| 51. |
- Cao, Xin, et al.
(författare)
-
A New Method for Simplifying Complex DC Systems and Obtaining the Controller Droop Coefficients
- 2022
-
Ingår i: IEEE Transactions on Power Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8950 .- 1558-0679. ; 37:2, s. 996-1006
-
Tidskriftsartikel (refereegranskat)abstract
- DC grid has become an important application in power transmission. However, the exist works only have the method to obtain the droop coefficient in a radial topology. Also, this droop coefficient is for V-I droop control. There is no such like method to obtain the droop coefficient for the P-V droop control. This paper proposed a new method for a complex dc grid to obtain the droop coefficients. Firstly, based on the converter control strategies, the types of converter were classified. It will help to find out which kinds of converter can be participated into the dc-side voltage control. Secondly, a virtual node was defined, and the matrix of the dc grid was reshaped to fit the new added virtual node by using the proposed simplification method. An example was shown how this method worked. After that a new method of calculating the P-V droop coefficient was proposed. Finally, a simulation model was investigated to verify if the proposed method can operate in a real system. The results showed that the simplification method can ensure the mathematical relationships of the dc system. And simulations show good performances of the droop coefficient calculation method.
|
|
| 52. |
- Ciftci, Baris, 1987-, et al.
(författare)
-
A Proposal for Wireless Control of Submodules in Modular Multilevel Converters
- 2018
-
Konferensbidrag (refereegranskat)abstract
- The modular multilevel converter is one of the most preferred converters for high-power conversion applications. Wireless control of the submodules can contribute to its evolution by lowering the material and labor costs of cabling and by increasing the availability of the converter. However, wireless control leads to many challenges for the control and modulation of the converter as well as for proper low-latency high-reliability communication. This paper investigates the tolerable asynchronism between phase-shifted carriers used in modulation from a wireless control point of view and proposes a control method along with communication protocol for wireless control. The functionality of the proposed method is validated by computer simulations in steady state.
|
|
| 53. |
- Ciftci, Baris, et al.
(författare)
-
Simple Distributed Control for Modular Multilevel Converters
- 2019
-
Ingår i: 2019 21st European Conference on Power Electronics and Applications, EPE 2019 ECCE Europe. - Brussels : European Power Electronics and Drives Association. - 9789075815306
-
Konferensbidrag (refereegranskat)abstract
- The central control of MMC becomes demanding in computation power and communication bandwidth as the number of submodules increase. Distributed control methods can overcome these bottlenecks. In this paper, a simple distributed control method together with synchronization of modulation carriers in the submodules is presented. The proposal is implemented on a lab-scale MMC with asynchronous-serial communication on a star network between the central and local controllers. It is shown that the proposed control method works satisfactorily in the steady state. The method can be applied as is to MMCs with any number of submodules per arm.
|
|
| 54. |
- Ciftci, Baris, et al.
(författare)
-
Wireless Communication in Modular Multilevel Converters and Electromagnetic Interference Characterization
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The wireless control of modular multilevel converter (MMC) submodules was recently proposed. The success of the control depends on specialized control methods suitable for wireless communication and a properly designed wireless communication network in the MMC valve hall while aiming for low latency and high reliability. The wireless communication in the hall can be affected by the electromagnetic interference (EMI) of MMC submodules, voltage and current transients. In this article, firstly, a wireless communication network based on 5G New Radio is designed for an example full-scale MMC valve hall. After that, radiated EMI characteristics of MMC submodules with different voltage and current ratings and two dc circuit breakers are measured. The effects of EMI on wireless communication in the multi-GHz frequency band are tested. The interference from the components is confined below 500 MHz, and the wireless communication with 5825 MHz center frequency is not affected by the interference.
|
|
| 55. |
- Ciftci, Baris, 1987-, et al.
(författare)
-
Wireless Communication in Modular Multilevel Converters and Electromagnetic Interference Characterization
- 2022
-
Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; , s. 38189-38201
-
Tidskriftsartikel (refereegranskat)abstract
- The wireless control of modular multilevel converter (MMC) submodules was recently proposed. The success of the control depends on specialized control methods suitable for wireless communication and a properly designed wireless communication network in the MMC valve hall while aiming for low latency and high reliability. The wireless communication in the hall can be affected by the electromagnetic interference (EMI) of MMC submodules, voltage and current transients. In this article, firstly, a wireless communication network based on 5G New Radio is designed for an example full-scale MMC valve hall. After that, the radiated EMI characteristics of the MMC submodules with different voltage and current ratings and two dc circuit breakers are measured. The effects of EMI on wireless communication in the multi-GHz frequency band are tested. The interference from the components is confined below 500 MHz, and the wireless communication with 5825 MHz center frequency is not affected by the interference.
|
|
| 56. |
- Ciftci, Baris, et al.
(författare)
-
Wireless control of modular multilevel converter autonomous submodules : 23rd European Conference on Power Electronics and Applications
- 2021
-
Ingår i: Proceedings 23rd European Conference on Power Electronics and Applications. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- The wireless control of modular multilevel converter (MMC) submodules might offer advantages for MMCs with a high number of submodules. However, the control system should tolerate the stochastic nature of the wireless communication, continue the operation flawlessly or, at least, avoid overcurrents, overvoltages, and component failures. The previously proposed control methods enabled to control the submodules wirelessly with consecutive communication errors up to hundreds of control cycles. The submodule control method in this paper facilitates the MMC to safely overcome communication errors that last longer and when the MMC experiences significant electrical disturbances during the errors. The submodules are proposed to operate autonomously by implementing a replica of the central controller in the submodules and drive the replicas based on the local variables and the previously received data. The simulation and experimental results verify the proposed control method.
|
|
| 57. |
- Ciftci, Baris, et al.
(författare)
-
Wireless Control of Modular Multilevel Converter Submodules
- 2021
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 36:7, s. 8439-8453
-
Tidskriftsartikel (refereegranskat)abstract
- Wireless control of modular multilevel converter (MMC) submodules offers several potential benefits to exploit, such as decreased converter costs and ease in converter installation. However, wireless control comes with several challenging engineering requirements. The control methods used with wired communication networks are not directly applicable to the wireless control due to the latency and reliability differences of wired and wireless networks. This article reviews the existing control architectures of MMCs and proposes a control and communication method for wireless submodule control. Also, a synchronization method for pulsewidth modulation carriers is proposed suitable for wireless control. The imperfections of wireless communication, such as higher latency and packet losses compared to wired communication, are analyzed for the operation of MMCs. The latency is fixed with a proper controller and wireless network design. The converter is rendered immune to the packet losses by decreasing the closed-loop control bandwidth. The functionality of the proposal is verified, for the first time, experimentally on a laboratory-scale MMC using a simple wireless network. It is shown that wireless control of MMC submodules with the proposed approach can perform comparably to the wired control.
|
|
| 58. |
- Ciftci, Baris, 1987-
(författare)
-
Wireless Control of Modular Multilevel Converter Submodules
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The modular multilevel converter (MMC) has extensively been used in high-voltage, high-power applications such as high-voltage dc transmission systems and flexible alternating current transmission systems. The control of MMC submodules is conventionally realized using wired communication systems. However, MMCs in high-power applications consist of up to thousands of submodules. Significant issues arise with the wired communication systems in the MMC valve halls of these applications, including considerable workforce and time requirements for the cable deployment.The main objective of this thesis is to propose a wireless control method for MMC submodules. Wireless communication has fundamental differences from wired communication regarding latency and reliability. Since the control of submodules is a time-critical process, the MMC internal control and modulation methods used with wired communication systems are not directly applicable to wireless communication systems.A wireless control method is proposed for the MMC submodules. The proposal is based on the distributed control of MMCs, where the control and modulation tasks are shared between a central controller and the submodule controllers. The fundamental data to transmit wirelessly is the insertion indices for each of the MMC arms and the synchronization signal for the modulation carriers generated in the submodules. The amount and the cycle time of the time-critical wireless data are in the range of tens of bytes and hundreds of microseconds and are independent of the total number of submodules. The proposal is experimentally verified on a laboratory-scale MMC.The original proposal is enhanced against the communication errors such that the submodules suffering from the errors can continue their modulation smoothly and uninterruptedly. If continuing the modulation is not feasible in case of very long-lasting communication errors, the submodules switch to a safe operation mode to avoid faults in the MMC. Moreover, wireless control of submodules with ac-side faults is analyzed. The MMC rides through the ac-side faults even with a complete loss of communication before or after the fault instant.A wireless communication network based on 5G New Radio is designed theoretically for an example full-scale MMC valve hall according to the proposed wireless control method. It is evaluated that the latency and reliability of the proposed communication solution can correspond to the proposed wireless control method requirements. Finally, the electromagnetic interference from the MMC submodules is measured as below 500 MHz, which does not affect a wireless communication held in the multi-GHz range.
|
|
| 59. |
- Ciftci, Baris, et al.
(författare)
-
Wireless control of modular multilevel converter submodules under ac-side faults
- 2021
-
Konferensbidrag (refereegranskat)abstract
- Wireless control of modular multilevel converter (MMC) submodules has been offered recently with potentially lower cost and higher availability advantages for the converter station. In this paper, the wireless control of MMC submodules under ac-side faults is investigated. The central controller of the MMC is equipped for the unbalanced grid conditions. Local current controllers in the submodules are operated autonomously in case of loss of wireless communication during the fault. A set of simulations with single line-to-ground, line-to-line, and three-phase-to-ground faults reveal that the MMC rides through the faults in all the cases with the expected communication conditions or when the communication is lost before or after the fault instant.
|
|
| 60. |
- Ciftci, Baris, et al.
(författare)
-
Wireless Control of Modular Multilevel Converter Submodules With Communication Errors
- 2022
-
Ingår i: IEEE Transactions on Industrial Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0278-0046 .- 1557-9948. ; 69:11, s. 11644-11653
-
Tidskriftsartikel (refereegranskat)abstract
- Wireless control of modular multilevel converter (MMC) submodules can benefit from different points of view, such as lower converter cost and shorter installation time. In return for the advantages, the stochastic performance of wireless communication networks necessitates an advanced converter control system immune to the losses and delays of the wirelessly transmitted data. This paper proposes an advancement to the distributed control of MMCs to utilize in wireless submodule control. Using the proposed method, the operation of the MMC continues smoothly and uninterruptedly during wireless communication errors. The previously proposed submodule wireless control concept relies on implementing the modulation and individual submodule-capacitor-voltage control in the submodules using the insertion indices transmitted from a central controller. This paper takes the concept as a basis and introduces to synthesize the indices autonomously in the submodules during the communication errors. This new approach allows the MMC continue its operation when one, some, or all submodules suffer from communication errors for a limited time. The proposal is validated experimentally on a laboratory-scale MMC.
|
|
| 61. |
|
|
| 62. |
- Demetriades, Georgios D., et al.
(författare)
-
Characterization of the Dual-Active Bridge Topology for High-Power Applications Employing a Duty-Cycle Modulation
- 2008
-
Ingår i: 2008 IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-10. - NEW YORK, NY : IEEE. - 9781424416677 ; , s. 2791-2798
-
Konferensbidrag (refereegranskat)abstract
- In the present paper the Dual-Active Bridgetopology employing a duty-cycle modulation is studied. Thebehavior of the converter at steady-state is examined.Additionally, the small-signal model of the topology ispresented and the dynamic behavior is examined.Simulations and experimental results are presented. It isworth noticing that the converter is operated under softswitchingconditions in a wide load range.
|
|
| 63. |
- Demetriades, Georgios D., et al.
(författare)
-
Dynamic Modeling of the Dual-Active Bridge Topology for High-Power Applications
- 2008
-
Ingår i: 2008 IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-10. - NEW YORK : IEEE. - 9781424416677 ; , s. 457-464
-
Konferensbidrag (refereegranskat)abstract
- In the present paper the staedy-state and thedynamic behavior of the Dual-Active Bridge topology havebeen studied. The small-signal model of the converter hasbeen derived and theoretical and experimental results arepresented.The Dual-Active Bridge is an attractive solution for highpowerapplications where a bi-directional operation is needed.
|
|
| 64. |
|
|
| 65. |
- Haider, Arif, et al.
(författare)
-
Open-loop approach for control of multi-terminal DC systems based on modular multilevel converters
- 2011
-
Ingår i: Proceedings of the 2011-14th European Conference on Power Electronics and Applications (EPE 2011). - 9781612841670 - 9789075815153
-
Konferensbidrag (refereegranskat)abstract
- In this paper a multi-terminal direct current (MTDC) system with modular multilevel converters (M2Cs) is suggested. An open loop control method is used for the control of the converters. Each converter is modeled with 36 sub-modules per arm with a total of 216 sub-modules consisting of half bridges. Power-synchronization control is used instead of a phase-locked loop (PLL) for synchronization. Thus, the short circuit capacities of the ac systems are no longer limiting factors and the instability caused by the PLL in weak ac systems is avoided [10]. A direct voltage controller is implemented with power-synchronization control as an inner loop in one station. Several scenarios are analyzed to demonstrate control flexibility and ride-through capability for grid transients. By means of analytical calculations and time simulations in PSCAD/EMTDC, the validity of the proposed MTDC system is confirmed.
|
|
| 66. |
- Harnefors, Lennart, et al.
(författare)
-
A general algorithm for speed and position estimation of AC motors
- 2000
-
Ingår i: IEEE Transactions on Industrial Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0278-0046 .- 1557-9948. ; 47:1, s. 77-83
-
Tidskriftsartikel (refereegranskat)abstract
- A computationally efficient speed and position estimation algorithm, generally applicable to AC motor drives, is designed and analyzed. Applications include: (a) sensorless permanent-magnet and reluctance synchronous motor drives using the fundamental excitation as information source; (b) sensorless drives using saliency and signal injection; and (c) sensored drives using resolvers. Particular attention is given for case (a). Low parameter sensitivity in the entire speed range (except at low speeds for the reluctance motor)-implying a small position estimation error-and good dynamic properties at nominal speeds are verified.
|
|
| 67. |
- Harnefors, Lennart, et al.
(författare)
-
Dynamic modeling of modular multilevel converters
- 2011
-
Ingår i: Proceedings of the 2011-14th European Conference on Power Electronics and Applications (EPE 2011). - 9781612841670 - 9789075815153
-
Konferensbidrag (refereegranskat)abstract
- Theory for the dynamics of modular multilevel converters is developed in this paper. It is shown that the sum capacitor voltage in each arm often can be considered instead of the individual capacitor voltages, thereby significantly reducing the complexity of the system model. A selection of the so-called insertion indices, which compensates for the sum-capacitor-voltage ripples, is considered. The system which results for this selection is analyzed, and is shown to be asymptotically stable. Finally, explicit formulas for the steady-state sum-capacitor-voltage ripples are derived.
|
|
| 68. |
|
|
| 69. |
- Harnefors, Lennart, et al.
(författare)
-
Model-Based Current Control of AC Machines Using the Internal Model Control Method
- 1998
-
Ingår i: IEEE transactions on industry applications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0093-9994 .- 1939-9367. ; 34:1, s. 133-141
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, the internal model control (IMC) method is applied to AC machine current control. Permanent magnet synchronous machines and induction machines are considered. The result is synchronous-frame proportional integral (PI) or PI-type controllers, the parameters (gain and integration time) of which are expressed directly in certain machine parameters and the desired closed-loop bandwidth. This simplifies the controller design procedure, eliminating or reducing the need for trial-and-error steps, and is the main purpose for using IMC.
|
|
| 70. |
|
|
| 71. |
|
|
| 72. |
- Harnefors, Lennart, et al.
(författare)
-
Robust Current Control of AC Machines Using the Internal Model Control Method
- 1995
-
Konferensbidrag (refereegranskat)abstract
- In the present paper, the internal model control (IMC) method is introduced and applied to AC machine current control. A permanent magnet synchronous machine is used as an example. It is shown that the IMC design is straightforward and the resulting controller is simple to implement. The controller parameters are expressed in the machine parameters and the desired closed-loop rise time. The extra cost of implementation compared to PI control is negligible. It is further shown that IMC is able to outperform PI control with as well as without decoupling with respect to dq variable interaction in the presence of parameter deviations.
|
|
| 73. |
- Heinig, Stefanie, et al.
(författare)
-
Auxiliary Power Supplies for High-Power Converter Submodules : State of the Art and Future Prospects
- 2022
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 37:6, s. 6807-6820
-
Tidskriftsartikel (refereegranskat)abstract
- Recent developments in medium-voltage (MV) silicon and silicon carbide (SiC) power semiconductor devices are challenging state-of-the-art converter and auxiliary power supply (APS) designs. The APS is an important converter component, which energizes the gate-drive units and, therefore, has an influence on the overall reliability and efficiency of the converter system. There has, however, been comparably little research on how the APS of high-power converter submodules can be realized, in particular, for high-voltage applications. New, or improved, solutions may build on state-of-the-art topologies in the near future, but utilize MV SiC technology in the APS circuit itself to enable improved efficiency, reliability, simplicity, and compactness. Externally-fed APS concepts could provide several further advantages. Their various benefits on converter and system level may enable them to be a competitive solution for future APS concepts. Especially, light-based power supply systems are considered most useful since they offer extreme voltage isolation capability and immunity to electromagnetic interference. This article presents a review of the wide range of solutions for APSs, possible implementation options, and the most important design considerations. The different solutions are evaluated in a qualitative fashion, providing an overview of available APS concepts with regard to the requirements for high-power converter applications.
|
|
| 74. |
- Heinig, Stefanie, et al.
(författare)
-
Auxiliary Power Supplies for High-Power Converter Submodules: State-of-the-Art and Future Prospects
- 2020
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Recent developments in high-voltage (HV) silicon and silicon carbide (SiC) power semiconductor devices are challenging state-of-the-art converter and auxiliary power supply (APS) designs. There has been comparably little research on how the APS of converter submodules can be realized. The APS is, however, an important converter component, which energizes the gate-drive units and, therefore, has an influence on the overall reliability and efficiency of the converter system. The wide range of possible solutions for APSs motivates an overview of state-ofthe- art and alternative concepts. Such a review is presented in this article, along with a qualitative evaluation regarding APS requirements for high-power converter applications.Moreover, future prospects of internal and external APS designs are discussed. Internal solutions may build on state-of-the-art topologies in the near future, but utilize HV SiC technology in the APS circuit itself to enable improved efficiency, reliability, simplicity, and compactness. The active voltage-divider-based APS is a promising concept if the required power is relatively low. Series-connected bootstrap circuits or snubber-based power tapping could provide a reduction of complexity and cost.It is recognized that several advantages are achievable by employing external APS concepts. Light-based power supply systems, comparably expensive today but under rapid development and with optimistic cost predictions, are considered most useful in this respect. Their extreme voltage isolation capability and immunity to electromagnetic interference, combined with various benefits on converter and system level, enable them to be a competitive solution for future APS concepts
|
|
| 75. |
- Heinig, Stefanie, et al.
(författare)
-
Implications of Capacitor Voltage Imbalance on the Operation of the Semi-Full-Bridge Submodule
- 2019
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 34:10, s. 9520-9535
-
Tidskriftsartikel (refereegranskat)abstract
- Future meshed high-voltage direct current grids require modular multilevel converters with extended functionality. One of the most interesting new submodule topologies is the semi-full-bridge because it enables efficient handling of DC-side short circuits while having reduced power losses compared to an implementation with full-bridge submodules. However, the semi-full-bridge submodule requires the parallel connection of capacitors during normal operation which can cause a high redistribution current in case the voltages of the two submodule capacitors are not equal. The maximum voltage difference and resulting redistribution current have been studied analytically, by means of simulations and in a full-scale standalone submodule laboratory setup. The most critical parameter is the capacitance mismatch between the two capacitors. The experimental results from the full-scale prototype show that the redistribution current peaks at 500A if the voltage difference is 10V before paralleling and increases to 2500A if the difference is 40V. However, neglecting very unlikely cases, the maximum voltage difference predicted by simulations is not higher than 20-30V for the considered case. Among other measures, a balancing controller is proposed which reduces the voltage difference safely if a certain maximum value is surpassed. The operating principle of the controller is described in detail and verified experimentally on a down-scaled submodule within a modular multilevel converter prototype. It can be concluded that excessively high redistribution currents can be prevented. Consequently, they are no obstacle for using the semi-full-bridge submodule in future HVDC converters.
|
|
| 76. |
- Heinig, Stefanie
(författare)
-
Main Circuits, Submodules, and Auxiliary Power Concepts for Converters in HVDC Grids
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In order to enable the massive introduction of renewable energies the need for high-voltage direct current (HVDC) grids is anticipated. Large, globally interconnected HVDC networks will likely be the most cost-efficient means to balance electricity demand and available generation. In a meshed system it is important to ensure reliability, robustness, failure management, and fast protection of equipment. In case of a failure somewhere in the grid, the remaining system must be kept operational. State-of-the-art converter implementations are either not adapted to future system requirements or lead to increased losses, cost, and converter footprint. Therefore, this thesis examines several aspects of how to improve the HVDC converter design and functionality with the ultimate aim of developing reliable, highly efficient, cost-effective, more compact and lightweight converters.Advancements are made on several levels of the converter hardware hierarchy. Main circuits, submodule (SM) topologies, and auxiliary power supply (APS) concepts are investigated and new solutions are proposed. On main-circuit level, different voltage-source converters (VSCs) are evaluated in terms of their energy storage elements. This is useful to compare the physical volume of capacitors required by each topology and, thus, to address the need to develop more compact converter stations. The theoretical analysis indicates that the required energy storage of the alternate arm converter (AAC) is smaller compared to the modular multilevel converter (MMC).On SM level, new topologies are evaluated with the goal to find topologies, which enable efficient handling of dc-side short circuits, reduction of power loss, and lower SM capacitance. The semi-full-bridge (SFB) SM is identified as one of the most promising topologies from this point of view and is investigated in detail. A control concept for capacitor balancing and several options for improved operation of the SFB are presented. Furthermore, a novel SM cluster topology is proposed which features low conduction losses and increased protection against explosion.The availability of a reliable APS system is crucial for equipment in future HVDC grids. Therefore, APS solutions are investigated considering design complexity, reliable performance, and power consumption. This thesis presents a novel combined optical power and data transmission concept which is tailored to the specific requirements of HVDC converters employing high-voltage (HV) silicon carbide (SiC) devices. The proposed concept offers a robust solution for isolated APS and signal transmission across any voltage barrier.
|
|
| 77. |
- Heinig, Stefanie, et al.
(författare)
-
Reduction of Switching Frequency for the Semi-Full-Bridge Submodule Using Alternative Bypass States
- 2018
-
Ingår i: 2018 20TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'18 ECCE EUROPE). - : IEEE. - 9789075815283
-
Konferensbidrag (refereegranskat)abstract
- As regards modular multilevel converter submodules, a different number of switches may be involved in the transitions between voltage levels depending on the submodule type and choice of switching states. In this paper, an investigation of the average switching frequency associated with different choices of bypass states is performed for the semi-full-bridge submodule. Theoretical considerations and simulation results show that the average switching frequency per device can be halved by using the proposed alternative bypass state. Moreover, the switching losses can be reduced by up to 60%. Finally, a comparative study with the full-bridge submodule has been conducted.
|
|
| 78. |
- Heinig, Stefanie, et al.
(författare)
-
Single-Fiber Combined Optical Power and Data Transmission for High-Voltage Applications
- 2020
-
Ingår i: Proceedings of the 46th Annual Conference of the IEEE Industrial Electronics Society, IECON 2020. - : Institute of Electrical and Electronics Engineers (IEEE).
-
Konferensbidrag (refereegranskat)abstract
- In this paper, power-over-fiber technology is used for combined power and data transfer applying amplitude-modulated light representing a pulse-width modulated signal that could be used for control of, for instance, power semiconductor devices in high-power converters. Even though the concept is generally applicable, an experimental verification aiming for a gate-driver of a switch in a modular multilevel converter is presented. In order to achieve a good resilience against electromagnetic noise, a concept where the modulated light is demodulated as a comparably powerful current signal is employed. A 5 MHz boost converter steps up the voltage to 15-20 V, such that silicon or silicon-carbide based power devices could be controlled. From the results, it can be concluded that it is possible to achieve transmission of a control signal with a latency of less than 500 ns for a gate drive unit of a high-power converter. The concept can easily be scaled up to powers of several watt.
|
|
| 79. |
- Heuvelmans, Matthijs
(författare)
-
Cost-effective Cells for High-power Modular Multilevel Converters
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The modular multilevel converter (MMC) topology was introduced in 2003and has since been receiving considerable attention from industry and academia.Notable benefits compared to two- or three-level voltage source convertersare its scalability, low switching losses, low output filter requirementsand ease of adding redundancy combined with fail-safe operation. There area number of disadvantages, such as the use of large bus capacitors and complexityof control. However, with currently predominant switch technology forhigh power levels, which are bipolar silicon devices, the benefits outweigh thedisadvantages. The use of integrated gate commutated thyristors (IGCTs) inan MMC is an attractive option compared to using IGBTs due to their robustnessand low conduction losses. Switching losses are of lesser importance,but not negligible.The objectives of this work are to contribute to a reduction in equipmentcost and to a decrease power loss in HVDC and STATCOM installations.The approach to achieve those objectives is by using the auxiliary resonantcommutated pole topology in IGCT-based MMC. In case thyristors are usedas auxiliary switches, the total amount of needed hardware does not differsignificantly from a hard-switched solution which needs a di/dt reactor and asnubber. The reduced switching losses in the main switches (IGCTs) lead toan efficiency increase, but also to the possibility of using higher-voltage devicesthat would otherwise be impracticable. This in turn can lead to a reduction inhardware cost due to a lower number of cells and lower conduction losses. Inaddition, the improved switching conditions allow for an increase in turn-offcurrent capability. Practical aspects that are also treated in this work are theuse of snubber circuits for the auxiliary switch, and the behaviour under ashoot-through. The latter aspect is essential for practical use in high-powerMMCs. In this work a fault-tolerant soft-switching cell is presented, whichallows for a current limiting series inductance between the main switches andthe dc-bus capacitor without causing a problematic voltage overshoot.
|
|
| 80. |
- Hu, Jiawei, et al.
(författare)
-
Collaborative Emergency Control Strategy Providing Transient Stability after HVDC-link Blocking
- 2022
-
Ingår i: EI2 2022. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 1051-1056
-
Konferensbidrag (refereegranskat)abstract
- Continuous commutation failures of line-commutated high-voltage direct current converter caused by AC faults lead to the blocking of HVDC-link. This may seriously threaten the stability of post-fault power system. Therefore, a collaborative emergency control strategy making use of DC power support is presented to guarantee transient stability after HVDC-link blocking. Firstly, the control enabling criterion is defined based on the variation characteristics of the phase trajectory slope during the first swing, while the analytical equation between the needed control quantity and the system parameters is derived. Secondly, the mathematical relation between the provided control quantity and the number of HVDC-links participating in the power support is deduced, and the participation sequence is determined on the basis of the post-fault stable equilibrium points. Additionally, the time delay of the whole implementation is considered. Finally, the effectiveness of presented control strategy is validated using the improved IEEE 68-bus AC/DC hybrid power system.
|
|
| 81. |
- Ilves, Kalle, et al.
(författare)
-
A new modulation method for the modular multilevel converter allowing fundamental switching frequency
- 2011
-
Ingår i: IEEE 8th International Conference on Power Electronics and ECCE Asia (ICPE & ECCE), 2011. - : IEEE. - 9781612849560 ; , s. 991-998
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a new modulation method for the modular multilevel converter. The proposed method is based on a fixed pulse pattern where harmonic elimination methods can be applied. Modulation methods with harmonic elimination based on calculated pulse patterns have been presented for other multilevel topologies. However, similar modulation schemes have not yet been presented for the modular multilevel topology. In the proposed modulation method, the pulse pattern is chosen in such a way that the stored energy in each submodule remains stable. It is shown that this can be done at the fundamental switching frequency without measuring the capacitor voltages or using any other form of feedback control. Such a modulation scheme has not been presented before. The theoretical results are verified by both simulations and experimental results. The simulation results show successful operation at the fundamental switching frequency with a larger number of submodules. When a smaller number of submodules are used, harmonic elimination methods may be applied. This is verified experimentally on a converter with eight submodules per phase leg. The experimental results verify that stable operation can be maintained at the fundamental switching frequency while successfully eliminating the fifth harmonic in the ac-side voltage.
|
|
| 82. |
- Ilves, Kalle, et al.
(författare)
-
Analysis of arm current harmonics in modular multilevel converters with main-circuit filters
- 2012
-
Ingår i: International Multi-Conference on Systems, Signals and Devices, SSD 2012 - Summary Proceedings. - : IEEE. - 9781467315906
-
Konferensbidrag (refereegranskat)abstract
- In a modular multilevel converter the circulating current that flows through each phase leg can affect the performance and efficiency of the converter. If measures are not taken to control the circulating current, it will inevitably contain a second-order harmonic. There are various solutions for eliminating this second-order harmonic. One of the proposed solutions includes a main-circuit filter that is tuned to block the second-order harmonic in the circulating current. This paper presents an analytical relation between the ac-side current and the higher-order harmonics in the circulating current when such a filter is used. It is found that when third-order harmonic injection is used, a large fourth-order harmonic component may appear in the circulating current. This is verified by simulating a 32-MVA converter designed for grid connected applications. The simulation results support the conclusion that it is essential to take this effect into consideration when designing the main-circuit filter.
|
|
| 83. |
- Ilves, Kalle, et al.
(författare)
-
Controlling the ac-side voltage waveform in a modular multilevel converter with low energy-storage capability
- 2011
-
Ingår i: Proceedings of the 2011-14th European Conference on Power Electronics and Applications (EPE 2011). - 9781612841670 - 9789075815153 ; , s. 1-8
-
Konferensbidrag (refereegranskat)abstract
- During nominal operation of a modular multilevel converter the stored energy in the submodule capacitors will vary with time. If the energy storage capability of the capacitors is relatively small compared to the energy variations, this will give large variations in the capacitor voltages. These voltage variations will distort the ac-side voltage waveform and induce harmonic components in the current that is circulating between the dc terminals. The adverse effects on the ac-side voltage can be compensated for by identifying the factors that cause the distortion. It is shown that the compensation can be done by means of feed forward control while maintaining stable operating conditions and thus eliminating the need of additional stabilizing controllers. It is also shown that the voltage controller can be combined with a circulating current controller that removes the harmonics in the current that is circulating between the dc terminals. The functionality of the proposed controller is verified by both simulations and experimental results from a 10 kVA laboratory prototype. The simulations illustrate how the proposed controller successfully removes the distortion from the ac-side voltage waveform. The experimental results demonstrate stable operation during a step transient when the output power is increased by 125%.
|
|
| 84. |
- Ilves, Kalle, et al.
(författare)
-
Steady-State Analysis of Interaction Between Harmonic Components of Arm and Line Quantities of Modular Multilevel Converters
- 2012
-
Ingår i: IEEE transactions on power electronics. - IEEE. - 0885-8993 .- 1941-0107. ; 27:1, s. 57-68
-
Tidskriftsartikel (refereegranskat)abstract
- The fundamental frequency component in the arm currents of a modular multilevel converter is a necessity for the operation of the converter, as is the connection and bypassing of the submodules. Inevitably, this will cause alternating components in the capacitor voltages. This paper investigates how the arm currents and capacitor voltages interact when the submodules are connected and bypassed in a sinusoidal manner. Equations that describe the circulating current that is caused by the variations in the total inserted voltage are derived. Resonant frequencies are identified and the resonant behaviour is verified by experimental results. It is also found that the effective values of the arm resistance and submodule capacitances can be extracted from the measurements by least square fitting of the analytical expressions to the measured values. Finally, the analytical expression for the arm currents is verified by experimental results.
|
|
| 85. |
- Jacobs, Keijo, et al.
(författare)
-
Comparative Evaluation of Voltage Source Converters with Silicon Carbide Semiconductor Devices for High-Voltage Direct Current Transmission
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Recent advancements in silicon carbide (SiC) powersemiconductor technology enable developments in the high-powersector, e.g., high-voltage direct current (HVdc) converters fortransmission, where today silicon (Si) devices are state-of-the-art. New submodule (SM) topologies for modular multilevelconverters (MMCs) offer benefits in combination with these newSiC semiconductors. This paper reviews developments in bothfields, SiC power semiconductor devices and SM topologies, andevaluates their combined performance in relation to core require-ments for HVdc converters: grid code compliance, reliability, andcost.A detailed comparison of SM topologies regarding theirstructural properties, design and control complexity, voltagecapability, losses, and fault handling is given. Alternatives tostate-of-the-art SMs with Si insulated-gate bipolar transistors(IGBTs) are proposed, and several promising design approachesare discussed. Most advantages can be gained from three tech-nology features. Firstly, SM bipolar capability enables dc faulthandling and reduced energy storage requirements. Secondly, SMtopologies with parallel conduction paths in combination with SiCmetal-oxide-semiconductor field effect transistors (MOSFETs)offer reduced losses. Thirdly, a higher SM voltage enabledby higher blocking voltage of SiC devices results in reducedconverter complexity. For the latter, ultra-high-voltage (UHV)bipolar devices, such as SiC IGBTs and SiC gate turn-offthyristors (GTOs), are envisioned
|
|
| 86. |
- Jacobs, Keijo, et al.
(författare)
-
Comparative Evaluation of Voltage Source Converters With Silicon Carbide Semiconductor Devices for High-Voltage Direct Current Transmission
- 2021
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 36:8, s. 8887-8906
-
Tidskriftsartikel (refereegranskat)abstract
- Recent advancements in silicon carbide (SiC) power semiconductor technology enable developments in the high-power sector, e.g., high-voltage-direct-current (HVdc) converters for transmission, where today silicon (Si) devices are state-of-the-art. New submodule (SM) topologies for modular multilevel converters offer benefits in combination with these new SiC semiconductors. This article reviews developments in both fields, SiC power semiconductor devices and SM topologies, and evaluates their combined performance in relation to core requirements for HVdc converters: grid code compliance, reliability, and cost. A detailed comparison of SM topologies regarding their structural properties, design and control complexity, voltage capability, losses, and fault handling is given. Alternatives to state-of-the-art SMs with Si insulated-gate bipolar transistors (IGBTs) are proposed, and several promising design approaches are discussed. Most advantages can be gained from three technology features. First, SM bipolar capability enables dc fault handling and reduced the energy storage requirements. Second, SM topologies with parallel conduction paths in combination with SiC metal-oxide-semiconductor field-effect transistors offer reduced losses. Third, a higher SM voltage enabled by a higher blocking voltage of SiC devices results in a reduced converter complexity. For the latter, ultrahigh-voltage bipolar devices, such as SiC IGBTs and SiC gate turn-off thyristors, are envisioned.
|
|
| 87. |
- Jacobs, Keijo, et al.
(författare)
-
Dissipation Loop for Shoot-Through Faults in HVDC Converter Cells
- 2018
-
Ingår i: 2018 INTERNATIONAL POWER ELECTRONICS CONFERENCE (IPEC-NIIGATA 2018 -ECCE ASIA). - : Institute of Electrical and Electronics Engineers (IEEE). - 9784886864055 ; , s. 3292-3298
-
Konferensbidrag (refereegranskat)abstract
- Converter cells for HVDC applications store large amounts of energy. This energy might be dissipated in a very short time in case of a shoot-through fault. Measures to avoid shoot-through or handle the extreme currents during a fault and prevent damage from neighboring components are essential to ensure a continued operation of the converter. With future high-voltage silicon carbide semiconductors, cell voltages can be increased leading to higher stored energy per cell. In cells with thyristor-based semiconductors, e.g. IGCTs, a di/dt reactor may have to be employed. This paper presents a method to handle the dissipated energy during shoot-through which makes use of the inherently needed di/dt reactor. The majority of the stored energy in the cell can be dissipated in a dedicated discharge loop formed by the reactor and an antiparallel bypass thyristor. After diverting the fault current into the dissipation loop, there is no current through any other component of the cell.
|
|
| 88. |
- Jacobs, Keijo, et al.
(författare)
-
Low Loss Submodule Cluster for Modular Multilevel Converters Suitable for Implementation with SiC MOSFETs
- 2019
-
Ingår i: Proceedings IEEE Energy Conversion Congress and Exposition 2019. - : IEEE. - 9781728103952 - 9781728103969
-
Konferensbidrag (refereegranskat)abstract
- In this paper, a novel submodule cluster topologyfor modular multilevel converters is proposed. The cluster iscomposed of an arbitrary amount of submodule segments. Dependingon the amount of capacitors in the cluster, the converterconduction losses can be reduced significantly. The topologyenables electronic protection against explosion, thus, reducingthe requirements for submodule bypass equipment. Implicationsfor the converter operation and functionality are investigated anda wireless control scheme is proposed.
|
|
| 89. |
- Jacobs, Keijo, et al.
(författare)
-
MMC Converter Cells Employing Ultrahigh-Voltage SiC Bipolar Power Semiconductors
- 2017
-
Ingår i: 2017 19th European Conference on Power Electronics and Applications (EPE'17 ECCE EUROPE). - : Institute of Electrical and Electronics Engineers (IEEE). - 9789075815276
-
Konferensbidrag (refereegranskat)abstract
- This paper investigates the benefits of using high-voltage converter cells for transmission applications. These cells employ ultrahigh-voltage SiC bipolar power semiconductors, which are optimized for low conduction losses. The Modular Multilevel Converter with half-bridge cells is used as a test case. The results indicate a reduction of converter volume and complexity, while maintaining low losses and harmonic performance.
|
|
| 90. |
- Jacobs, Keijo, 1988-
(författare)
-
Silicon-Carbide-Based High-Voltage Submodules for HVDC Voltage-Source Converters
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In order to transition to renewable energy sources and simultaneously meet the increasing demand for electrical energy, highly flexible and efficient grids are required. High-voltage direct-current (HVDC) transmission and grids are foreseen to be a vital part of the future electricity grid. Voltage source converters (VSCs), interfacing between HVDC and high-voltage alternating current (HVAC) technology, need to comply with grid code, and offer high reliability and cost efficiency. The state-of-the-art VSC topology is the modular multilevel converter (MMC), which offers tailored harmonic performance, modularity, fault handling, redundancy, and low losses.This thesis investigates improvements for VSCs enabled by novel silicon carbide (SiC) power semiconductor devices. These devices feature lower losses, higher blocking voltage, and higher maximum operation temperature. However, a co-design of the different hardware levels (i.e., converter, submodule (SM), power device, and semiconductor) is required to unleash their full potential. The thesis features contributions on several of these hardware levels, aiming at improvements regarding defined technical requirements for VSCs.It has been shown that, on converter level, future ultrahigh-voltage (UHV) SiC bipolar devices with blocking voltages of up to 50 kV have the potential for significant reduction of converter complexity, volume, and losses. The increased SM voltage is a challenge for internal fault handling, which can be met by a proposed novel SM feature, the discharge loop.On SM level, additional improvements are enabled by synergies between power semiconductor device technology and SM topology. A comparative evaluation of a large variety of SM topologies in combination with different SiC power semiconductor device technologies identifies several promising design approaches for future SMs. An alternative to the state-of-the-art half-bridge and full-bridge SM is the semi-full-bridge, which is investigated intensively. It features lower switch count and lower losses compared to the full-bridge, while offering DC fault handling capability. Another topology, the double-connected double-zero SM, features additional conduction loss reduction in combination with SiC metal-oxide-semiconductor field-effect transistors (MOSFETs), which is enabled by parallel current paths during certain switching states. A SM cluster enhancing this effect is proposed.Finally, results on the optimization of SiC PiN diodes via different charge carrier lifetime tailoring methods are presented. The target application is a high-voltage high-frequency LCC converter. In the future, such diodes will also be required as anti-parallel diodes for novel UHV bipolar SiC devices, as bootstrap diodes in gate drivers, and as a part of snubber circuits.
|
|
| 91. |
- Jacobs, Keijo, et al.
(författare)
-
Static and Dynamic Performance of Charge-Carrier Lifetime-Tailored High-Voltage SiC p-i-n Diodes with Capacitively Assisted Switching
- 2022
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers Inc.. - 0885-8993 .- 1941-0107. ; 37:10, s. 12065-12079
-
Tidskriftsartikel (refereegranskat)abstract
- Recent advancements in the silicon carbide (SiC) power semiconductor technology offer improvements for high-power converters, where today silicon (Si) devices are still dominant. Bipolar SiC devices feature particularly good conduction capability while blocking high voltages. With expected advances in SiC material quality and processing technology, resulting in higher charge carrier lifetimes, methods for tailoring will be required. In this article, three differently optimized 10-kV SiC p-i-n diodes are compared regarding their switching and conduction performance in a 50-kHz LCC converter with a high output voltage. The converter topology features capacitively assisted switching, resulting in reduced switching losses for diodes with short reverse recovery tails. One diode group was subjected to a novel carrier lifetime tailoring method, involving simultaneous annihilation and generation of carbon vacancies. Another group was tailored via proton irradiation. Tradeoffs for the optimization of the diodes are highlighted. The analysis is supported by circuit simulations, device simulations, static measurements, switching waveform measurements, and calorimetric loss measurements. The results show a total rectifier loss reduction of 37%, compared to a state-of-the-art implementation with eight 1-kV Si diodes. The switching losses account for 3%-19% of the total losses, indicating a much higher possible operation frequency.
|
|
| 92. |
|
|
| 93. |
- Jahn, Ilka
(författare)
-
Protection for Multiterminal HVDC Grids - A Digital Contribution
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis is to (1) enhance understanding of mechanisms that are important for the protection of high-voltage direct-current (HVDC) grids, and (2) suggest possible technical solutions. To that end, digital technologies were used both in simulation, as well as in a laboratory environment.Literature studies were carried out on fault detection algorithms and substation communication leading to a recommendation to use a combination of single- and double-ended algorithms for fault detection, as well as to use the EtherCAT protocol for substation communication.A limitation of simulation studies are possible parameter uncertainties. For that reason, large protection margins by design are important. The simulation part of this thesis includes, firstly, a study concerning protection margins showing the detrimental effect of not being able to share information in a multi-vendor context. Secondly, a new method is presented for holistic protection system design taking into account a large variety of parameters and making sure that no hardware or software constraints are violated. For this, genetic optimization was found to be the most suitable technique. It is found that the holistic method is particularly useful for complex optimization problems, such as HVDC grids with different DC circuit breaker opening times and no converter blocking. In one test case, the genetic optimization resulted in a 71% decrease of total inductor size compared to the initial dimensioning provided by an engineer.Due to the destructive nature of faults, HVDC protection can obviously not be systematically tested full-scale or even in a laboratory environment. Still, real-time testing using real controllers or protection devices is useful because it is more realistic than offline, electromagnetic transient simulations. In this thesis, an intelligent electronic device (IED) prototype for HVDC grid protection was developed, providing a crucial device for subsequent studies on IED type testing and HVDC protection system testing, both of which were conducted outside of this PhD work. A test of the IED prototype with actual fault recordings from an operational HVDC link further increased confidence in HVDC protection, because the successful testing is based on both a real protection IED, and a real fault recording, and not a simulation that could be subject to inaccuracies.Finally, based on the need to share information during design of a multivendor HVDC protection system, as well as control-related problems reported from the field, a proposal for open-source HVDC control and protection is put forward, aiming to enhance vendor-interoperability.
|
|
| 94. |
- Johannesson, Daniel, et al.
(författare)
-
Assessment of Junction Termination Extension Structures For Ultrahigh-Voltage Silicon Carbide Pin-Diodes; A Simulation Study
- 2021
-
Ingår i: IEEE Open Journal of Power Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2644-1314. ; 2, s. 304-314
-
Tidskriftsartikel (refereegranskat)abstract
- The junction termination extension (JTE) structures for ultrahigh-voltage (UHV) devices consumes a considerable part of the semiconductor chip area. The JTE area is closely related to chip performance, process yield and ultimately device cost. The JTE lengths for UHV devices (i.e., > 30 kV) are still unknown, not visible in the scientific literature and have therefore been predicted in this study by means of two-dimensional numerical simulations using the Sentaurus based technology computer-aided design (TCAD) tool. A previously reported space-modulated, two-zone JTE (SM-JTE) structure has been used as an input to set up a suitable TCAD model, which is further scaled to JTE lengths required for 40 kV class and 50 kV class SiC PiN diodes. The simulation results indicate that the SM-JTE requires an 1800 μm one-sided JTE length with 27 guard rings for a 40 kV theoretical PiN diode and 2700 μm with 36 guard rings for a 50 kV device, resulting in breakdown voltages of 41.4 kV and 51.7 kV, respectively. Moreover, the design considerations of different JTE categories are discussed with focus on the adaptability of the termination structures in ultrahigh-voltage devices, e.g., V B > 30 kV, which results in a comparison of the SM-JTE structure with other high-voltage JTE designs.
|
|
| 95. |
- Johannesson, Daniel, et al.
(författare)
-
Dynamic Avalanche Limit and Current Filamentation Onset Limit in 4H-Silicon Carbide High-Voltage Diodes
- 2021
-
Ingår i: IEEE Journal of Emerging and Selected Topics in Power Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-6777 .- 2168-6785. ; , s. 1-1
-
Tidskriftsartikel (refereegranskat)abstract
- Dynamic avalanche (DA) phenomena and current filament (CF) formation are two extreme conditions observed in high-power devices, setting the maximum limit on turn-on/off current capability and di/dt in Silicon-based bipolar devices. The properties of the Silicon Carbide (SiC) material enable devices with increased resilience for DA and CF compared to Si counterparts, and thus the SOA limits may be extended. In this study, the limit of DA and CF in SiC-based semiconductor structures are investigated by numerical TCAD simulations, for different current levels, di/dt, and temperatures for high-voltage devices (e.g., 20 kV class). DA is first indicated for di/dt beyond 105 kA/μs for current densities in the range of 50–1000 A/cm2, at 448 K. Similarly, stray inductance induced avalanche conditions are initiated above 33 kA/μs, while CF is initiated for di/dt starting from 83 kA/μs for current densities in the range of 8.3 kA/cm2. Moreover, the effects of the stray inductance in the main circuit loop are studied which may cause critical voltage transients during certain operating conditions. The outcome of the study may be useful to determine safe-operating-area limits and to be used as input for power electronic converter design as well as gate driver design for high-power electronic systems.
|
|
| 96. |
- Johannesson, Daniel, et al.
(författare)
-
Evaluation of Ultrahigh-Voltage 4H-SiC Gate Turn-Off Thyristors and Insulated-Gate Bipolar Transistors for High-Power Applications
- 2021
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 37:4, s. 4133-4147
-
Tidskriftsartikel (refereegranskat)abstract
- Technology-based computer-aided design (TCAD) models have been used to predict the static and dynamic performance of ultrahigh-voltage (UHV) 4H-Silicon Carbide (SiC) PiN diodes, insulated-gate bipolar transistors (IGBTs), and gate turn-off (GTO) thyristors designed for 2050 kV blocking voltage capability. The simulated forward voltage drops of 2050 kV device designs range between 3.15.6 V for PiN diodes, 4.210.0 V for IGBTs, and 3.47.8 V for GTO thyristors at 20 A/cm2 for room temperature operation. Moreover, with a low switching frequency application (i.e., 150 Hz) in mind, the switching energy losses using an 30 kV SiC GTO thyristor design are approximately EON/EOFF_GTO = 268/640 mJ, EON/EOFF_FWD = 388/6 mJ diode recovery losses, and EON/EOFF_SNUB = 954/22 mJ snubber component losses. The corresponding values for a SiC IGBT design are EON/EOFF_IGBT = 983/748 mJ, both operated at 448 K, A = 20 s, and with 30 A/cm2. The simulation output is used in a benchmark evaluation for a 1 GW, 640 kV application case, employing modular multilevel high-power converter legs comprising series-connected UHV SiC devices and state-of-the-art 4.5 kV Si bi-mode insulated-gate transistors (BiGTs). It is concluded that the high-voltage SiC power electronic building blocks present promising alternatives to existing high-voltage Si device counterparts in terms of system compactness and efficiency.
|
|
| 97. |
- Johannesson, Daniel, et al.
(författare)
-
Static and Dynamic Performance Prediction of Ultra-High-Voltage Silicon Carbide Insulated-Gate Bipolar Transistors
- 2021
-
Ingår i: IEEE transactions on power electronics. - 0885-8993 .- 1941-0107. ; 36:5, s. 5874-5891
-
Tidskriftsartikel (refereegranskat)abstract
- The performance of theoretical ultra-high-voltagepower semiconductor devices has been predicted by means ofnumerical simulations using the Sentaurus technology computeraideddesign tool. A general silicon carbide punch-throughinsulated-gate bipolar transistor (IGBT) structure has beenimplemented with suitable physics-based models and parametersto reflect the device characteristics in a wide range of deviceblocking voltages from 20 to 50 kV. The models for 20 kV classIGBTs have been implicitly validated by means of publishedexperimental results. Mixed-mode simulations were performedthat predicted total switching energy loss densities of 335, 629,906 and 999 mJ/cm2 for 20, 30, 40 and 50 kV class devicesrespectively, at 25ºC, JC = 20 A/cm2 and an ambipolar carrierlifetime of 20 μs. While the IGBT on-state forward voltage dropreduces, the switching losses increase with higher charge-carrierlifetime for a given current density (e.g., 20 A/cm2). The largespan of simulation results will be used as an input support to thedesign of future high-power converters.
|
|
| 98. |
- Johannesson, Daniel, et al.
(författare)
-
TCAD Model Calibration of High Voltage 4H-SiC Bipolar Junction Transistors
- 2019
-
Ingår i: Materials Science Forum. - : Trans Tech Publications, Ltd.. ; , s. 670-673
-
Konferensbidrag (refereegranskat)abstract
- In this project, a Technology CAD (TCAD) model has been calibrated and verified against experimental data of a 15 kV silicon carbide (SiC) bipolar junction transistor (BJT). The device structure of the high voltage BJT has been implemented in the Synopsys Sentaurus TCAD simulation platform and design of experiment simulations have been performed to extract and fine-tune device parameters and 4H-SiC material parameters to accurately reflect the 15 kV SiC BJT experimental results. The set of calibrated TCAD parameters may serve as a base for further investigations of various SiC device design and device operation in electrical circuits.
|
|
| 99. |
- Johannesson, Daniel
(författare)
-
Ultrahigh-Voltage Silicon Carbide Device Performance, Requirements, and Limitations in High-Power Applications
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increased awareness of the on-going climate change accelerates the electric energy system transformation from fossil-fueled power sources towards systems with larger portions of renewable energy sources. Moreover, the grid infrastructure requires reinforcements to cope with increasing electrical energy demand. Flexible AC transmission systems (FACTS) and high-voltage DC (HVDC) transmission systems allow higher grid capacity, efficient transmission over long distances and sub-sea electrical energy transfer. Efficient sub-sea transmission is required for off-shore wind- and intercontinental grid connections. It is predicted that basic power electronic building blocks (PEBB) utilizing SiC-based semiconductor devices will provide converter system benefits (e.g., reduced number of series connected devices, less complex system, lower energy losses, lower cooling requirements and smaller station footprint), in comparison to systems employing Si-based semiconductor devices. The main objective of this thesis is to design, evaluate and identify the performance, requirements, and limitations of high-voltage SiC devices suitable for high-power applications. The SiC semiconductor device characteristics have been investigated by two-dimensional numerical simulations and experiments to assess the suitability in high-power applications. A calibrated set of technology computer-aided design (TCAD) simulation models are used as foundation for estimating the performance of SiC PiN diodes, SiC insulated-gate bipolar transistors (IGBTs) and SiC gate turn-off (GTO) thyristors with blocking voltage capabilities in the range of 20–50 kV. The static and dynamic device performances are assessed along with related gate driver requirements and snubber design requirements. The devices characteristic are studied using physical parameters of device layer structures, device processing parameters, and varying circuit parameters using mixed-mode simulations that results in a wide range of data for device performance predictability. Moreover, the experimental characterization of 10 kV, 100 A SiC metal-oxide semiconductorfield-effect transistor (MOSFET) power modules are demonstrated and compared to Si counterparts. The junction termination extension (JTE) design aspects for 20, 30, 40, and 50 kV devices are investigated where the results are used to predict the active area ratio for each blocking voltage class. In addition, the limit of critical operating conditions such as dynamic avalanche and current filamentation are derived by TCAD simulations, which indicates that the critical operation points are significantly higher than that of Si-based counterparts. The wide-range simulation data have been used in benchmarking SiC-based devices with Si counterparts in an application case of a 1 GW, 640 kV, modular multilevel converter (MMC)-based HVDC system. The analytical benchmark model indicates an energy loss reduction to approximately half by employing SiC device configurations compared to state-of-the-art Si bi-mode insulated gate transistors (BiGTs). The low energy losses along with the benefits by reduction of system complexity, control hardware, cables, and fibers (due to a lower amount of PEBBs), the SiC converter design presents a promising alternative to existing Si-based high-power modular multilevel converters.
|
|
| 100. |
- Johannesson, Daniel, et al.
(författare)
-
Wide-Range Prediction of Ultra-High Voltage SiC IGBT Static Performance Using Calibrated TCAD Model
- 2020
-
Ingår i: Materials Science Forum. ; , s. 911-916
-
Konferensbidrag (refereegranskat)abstract
- In this paper, a technology computer-aided design (TCAD) model of a silicon carbide (SiC) insulated-gate bipolar transistor (IGBT) has been calibrated against previously reported experimental data. The calibrated TCAD model has been used to predict the static performance of theoretical SiC IGBTs with ultra-high blocking voltage capabilities in the range of 20-50 kV. The simulation results of transfer characteristics, IC-VGE, forward characteristics, IC-VCE, and blocking voltage characteristics are studied. The threshold voltage is approximately 5 V, and the forward voltage drop is ranging from VF = 4.2-10.0 V at IC = 20 A, using a charge carrier lifetime of τA = 20 μs. Furthermore, the forward voltage drop impact for different process dependent parameters (i.e., carrier lifetimes, mobility/scattering and trap related defects) and junction temperature are investigated in a parametric sensitivity analysis. The wide-range simulation results may be used as an input to facilitate high power converter design and evaluation. In this case, the TCAD simulated static characteristics of SiC IGBTs is compared to silicon (Si) IGBTs in a modular multilevel converter in a general highpower application. The results indicate several benefits and lower conduction energy losses using ultra-high voltage SiC IGBTs compared to Si IGBTs.
|
|
