| 1. |
- Andersson, A., et al.
(author)
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An analysis of inverter switching loss minimization based on discontinuous PWM for a salient-pole PMSM
- 2014
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In: 2014 16th European Conference on Power Electronics and Applications (EPE'14-ECCE Europe), Lappeenranta, Finland, 26-28 August 2014. - 2325-0313. - 9781479930159
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Conference paper (peer-reviewed)abstract
- This article presents the result of an inverter switching loss minimization technique based on discontinuous PWM patterns for a salient-pole PMSM with a two-level voltage source inverter for an automotive application. The suggested PWM patterns are evaluated using the resulting electromagnetic torque considering peak-to-peak ripple as well as the DC-current harmonic spectra. The study focuses on high rotational speeds, from 0.6-2.5 ωbase considering both current and voltage limitations. The analysis focuses on electromagnetic torque characteristics evaluated at steady state operation. The results show that the electromagnetic torque ripple is increased by up to 73 % and 78 % whereas the inverter switching losses is decreased by up to -17%and -41%for the EUDC driving cycle using DPWM30 and DPWM60, respectively.
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| 2. |
- Asimakopoulos, Panagiotis, 1985, et al.
(author)
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Design of a Modular Multilevel Converter as an Active Front-End for a magnet supply application
- 2014
-
In: 2014 16th European Conference on Power Electronics and Applications (EPE'14-ECCE Europe), Lappeenranta, Finland, 26-28 August 2014. - 2325-0313. - 9781479930159
-
Conference paper (peer-reviewed)abstract
- The aim of this work is to describe the general design procedure of a Modular Multilevel Converter (MMC) applied as an Active Front-End (AFE) for a magnet supply for beam accelerators. The dimensioning criteria for the converter and the dc-link capacitance are presented and the grid transformer requirements are set. Considering the converter design, the arm inductance calculation is based on the specifications for the arm-current ripple and the DC-link fault tolerance, but, also, on the limitation of the second harmonic and the second-order LC resonance of the arm current. The module capacitance value is evaluated by focusing on the required switching dynamics and the capacitor-voltage ripple according to a newly proposed graphical method. The loading of each semiconductor in the half bridge is calculated via simulation, indicating the unsymmetrical current distribution. It is concluded that the current distribution for each semiconductor depends on the mode of operation of the converter. The different criteria for the choice of the number of modules per arm are discussed. Finally, the complete system, including a model for the load and the converter control strategy applied to the converter is simulated and obtained results are presented.
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| 3. |
- Nilves, M., et al.
(author)
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Enhanced control strategy for MMC-based STATCOM for unbalanced load compensation
- 2014
-
In: 2014 16th European Conference on Power Electronics and Applications (EPE'14-ECCE Europe), Lappeenranta, Finland, 26-28 August 2014. - 2325-0313. - 9781479930159
-
Conference paper (peer-reviewed)abstract
- Modular Multilevel Converters (MMC) technology is today one of the preferred technology in HVDC and large STATCOM applications due to modularity, fault tolerance and high efficiency, but the voltage balancing becomes very challenging, especially during negative sequence current injection as required for load unbalance compensation. This paper proposes an improved balancing strategy for the delta configuration to overcome this situation based on the injection of a third harmonic zero sequence current. Simulation results have proved the effectiveness of the proposal even where different switching losses and capacitor tolerance are taken in consideration.
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| 4. |
- Palmberg, Eva, 1939, et al.
(author)
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Wireless Charging for vehicles-Some Key Elements
- 2014
-
In: 2014 16th European Conference on Power Electronics and Applications (EPE'14-ECCE Europe), Lappeenranta, Finland, 26-28 August 2014. - 2325-0313. - 9781479930159
-
Conference paper (peer-reviewed)abstract
- In this paper so called wireless charging is investigated, primarily considering applications such as charging hybrid or electric vehicles at stand-still. The base concept investigated is a sending and a receiving coil at various designs. The theory behind wireless energy transfer and the needed components are described and analyzed, showing how design aspects, frequencies, height and vertical displacement affect the results. Analytical expressions, measurements, as well as FEM analyses in 2D and 3D with two different FEM programs have been compared, with a reasonable agreement between methods.
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| 5. |
- Roshanfekr, Poopak, 1976, et al.
(author)
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Torque Ripple Reduction Methods for an Interior Permanent Magnet Synchronous Generator
- 2014
-
In: 2014 16th European Conference on Power Electronics and Applications (EPE'14-ECCE Europe), Lappeenranta, Finland, 26-28 August 2014. - 2325-0313. - 9781479930159
-
Conference paper (peer-reviewed)abstract
- This article presents the effect of different torque ripple reduction methods on the average torque and back-emf harmonics. Two methods are compared. One is skewing the stator of the machine and the other method is using a fractional slot winding for the machine. It has been shown that both methods reduce the torque ripple of the IPMSM by 70% while the impact on the average torque is ignorable. The back-emf harmonics will be also reduced.
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| 6. |
- Stellas, D., et al.
(author)
-
Position-sensorless control of a submersible PMSM fed over a long cable and two transformers
- 2014
-
In: 2014 16th European Conference on Power Electronics and Applications (EPE'14-ECCE Europe), Lappeenranta, Finland, 26-28 August 2014. - 2325-0313. - 9781479930159
-
Conference paper (peer-reviewed)abstract
- This paper proposes the combination of two sensorless control algorithms for the secure start-up and the efficient operation of a remotely-controlled PMSM. V / f control is applied during the start-up of the motor and vector control is used for operation at higher speeds. The investigated system consists of a long step-out configuration with a cable and two transformers between the PMSM and its VSD. The system is tested with simulations and with experiments on a lab model. The results demonstrate that V / f control can safely start the PMSM. The effect of the inertia of the rotating assembly, the load torque and the initial rotor position on the start-up performance of the system is investigated and the successful transition from V / f control to vector control is demonstrated.
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| 7. |
- Acquaviva, Alessandro, 1987, et al.
(author)
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Energy efficiency of a SiC MOSFET propulsion inverter accounting for the MOSFET's reverse conduction and the blanking time
- 2017
-
In: 2017 19th European Conference on Power Electronics and Applications. - 2325-0313. - 9789075815276
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Conference paper (peer-reviewed)abstract
- MOSFET devices have a body diode that allows reverse conduction, additionally, when a negative drain-source voltage is present, the MOSFET channel conduction can also be controlled by applying a gate-source voltage above the threshold voltage level. In a three phase inverter this results in parallel conduction of the diode and MOSFET when voltage and current differ in sign. This paper analyzes the beneficial effect of parallel operation of the two devices, taking into account the blanking time, on the conduction losses and total efficiency for a three phase SiC MOSFET inverter for traction application in electrified vehicles. The losses of the inverter are derived and presented as an analytical expression and compared with a numerical implementation showing a perfect match of the two. The total losses and efficiency of the inverter are derived and analyzed with and without reverse conduction for different operating points.
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| 8. |
- Asimakopoulos, Panagiotis, 1985, et al.
(author)
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Current Sharing inside a High Power IGBT Module at the Negative Temperature Coefficient Operating Region
- 2016
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In: 18th European Conference on Power Electronics and Applications, EPE 2016 ECCE Europe, Karlsruhe, Germany, 5-9 September 2016. - 2325-0313. - 9789075815245
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Conference paper (peer-reviewed)abstract
- This work investigates the current sharing effect of a high power Soft Punch Through IGBT module in the Negative Temperature Coefficient region. The unbalanced current sharing between two of the substrates is demonstrated for different current and temperature levels and its impact on the thermal stressing of the device is evaluated. The results indicate that the current asymmetry does not lead to a significant thermal stressing unbalance between the substrates.
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| 9. |
- Asimakopoulos, Panagiotis, 1985, et al.
(author)
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Thermal stressing mitigation possibility intended for a DC-current magnet supply based on high power IGBT modules
- 2017
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In: 2017 19th European Conference on Power Electronics and Applications. - 2325-0313. - 9789075815276
-
Conference paper (peer-reviewed)abstract
- This work investigates the possibility to reduce the thermal stressing of high power IGBT modules in a DC-current application. Using four load current profiles as examples, two mitigation strategies are presented and their benefit to the power stack in terms of lifetime prolongation is evaluated. In the final part of the work, the investigation focuses on the relation between the shape of the load current and the potential for thermal stressing limitation that the proposed mitigation strategies can provide.
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| 10. |
- Behrouzian, Ehsan, 1985, et al.
(author)
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Impact of capacitor balancing strategies on converter ratings for star-connected cascaded H-bridge STATCOM
- 2017
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In: 19th European IEEE Conference on Power Electronics and Applications (EPE'17 ECCE Europe). - 2325-0313. - 9789075815276
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Conference paper (peer-reviewed)abstract
- This paper presents a comparison between two DC-voltage balancing strategies for cascaded star-connected multilevel STATCOM: zero-sequence voltage, and negative-sequence current control. Different levels of unbalance and grid strengths are considered. The impact of the control strategies on the convert ratings in terms of voltage and current requirements are compared and the operating range of the converter using each control strategy is theoretically derived. The results show that for a given system ratings, the operating range of the converter using negative-sequence current control is wider than the zero-sequence voltage control when the STATCOM is connected to weak grids. On the contrary, in case of connection to strong grids the zero-sequence voltage control can provide wider operating range. PSCAD simulation results are provided to prove the theoretical results.
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