| 1. |
- Chompoobutrgool, Yuwa, et al.
(författare)
-
A fundamental study on damping control design using PMU signals from dominant inter-area oscillation paths
- 2012
-
Ingår i: North American Power Symposium (NAPS), 2012. - : IEEE. - 9781467323086 ; , s. 1-6
-
Konferensbidrag (refereegranskat)abstract
- This article presents a fundamental study on feedback control using different types of signals available from a dominant inter-area oscillation path; the passageway containing the highest content of the inter-area oscillations. Results from the previous studies verify the persistence and robustness of dominant path signals and suggest that using such signals, effective damping control may be achieved. To corroborate the implication, signals available from phasor measurement units (PMU) e.g. voltage phasors (magnitude and angle) from the dominant path are used as feedback inputs for a power system stabilizer (PSS) control design for damping enhancement. The corresponding performance are compared with those using generator speed, which is a commonly used signal though not available from PMUs, as inputs. Contrary to expectations found in common practice, that of speed being the one of the most effective signal for damping control, it is demonstrated here that their corresponding damping performance is inferior to those using voltage phasors as feedback inputs. A conceptualized two-area system is used to analyze damping performance throughout this study.
|
|
| 2. |
- Chompoobutrgool, Yuwa, 1984-, et al.
(författare)
-
Analysis of Time Delay Effects for Wide-Area Damping Control Design using Dominant Path Signals
- 2014
-
Ingår i: 2014 IEEE Power and Energy Society General Meeting. - : IEEE Computer Society. - 9781479964154 ; , s. 6938872-
-
Konferensbidrag (refereegranskat)abstract
- The purpose of this article is to investigate the effects of time delays for wide-area damping control design when signals from dominant inter-area oscillation paths are used as feedback inputs for damping controllers. The analysis is carried out using a two-area study system. Frequency and time-domain responses of a generator's terminal voltage when the PSS uses PMU signals subject to time delays will be compared and assessed. The analysis reveals that while modal observability of the dominant path signals corresponds to the gain of the open-loop system at the inter-area frequency, these properties are inversely proportional to their corresponding delay margins.
|
|
| 3. |
- Chompoobutrgool, Yuwa, 1984-
(författare)
-
Aspects of Wide-Area Damping Control Design using Dominant Path Synchrophasor Signals
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The presence of inter-area oscillations has long affected stability constraints, and therefore, limited the power transfer capacity of interconnected power systems. Adequate damping of these inter-area oscillations is, thus, necessary to secure system operation and ensure system reliability while increasing power transfers. Power system stabilizers (PSS) are the most common devices used to enhance the damping of such oscillations. Many studies have demonstrated that PSSs using remote signals may perform better than using local signals.The advent of phasor measurement units (PMU) makes remote or wide-area signals become available, which enables various important applications. Of particular interest is wide-area damping control (WADC), which aims to utilize remote or wide-area measurements to damp the inter-area oscillations. However, two main challenges in WADC design are (1) feedback controller input signal selection (which PMU signal is best to use?), and (2) latency (which is inherent in the transmission of the measurements) considerations.In response to the first challenge, this thesis proposes a concept called dominant inter-area oscillation path, which serves to pinpoint a set of candidate signals that can be used as the feedback controller inputs by locating the interconnected corridors where the inter-area modal contents are the most observable. Derivation, identification, and use of the dominant inter-area oscillation paths are demonstrated throughout the thesis. Extensive analysis on the relationships between the proposed set of signals and system properties regarding stability and robustness is presented. To tackle the second challenge, the impacts of time delays on the system performance when using the dominant path signals are investigated.To date, several studies have proposed different control design methods using various oscillation dampers to design WADC. Nevertheless, neither a systematic method nor a concept that encompasses fundamental knowledge on power system dynamics has yet been offered. The objective of this thesis is, thus, to propose an analytical framework based on the dominant path concept which is built upon fundamental principles for feedback controller input signal selection in WADC. With this framework, a proper and systematic approach is developed. The proposed method allows to select appropriate signals and use them to effectively mitigate the inter-area oscillations that constrain power transfer capacity and affect system stability.
|
|
| 4. |
- Chompoobutrgool, Yuwa, 1984-
(författare)
-
Concepts for Power System Small Signal Stability Analysis and Feedback Control Design Considering Synchrophasor Measurements
- 2012
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the Nordic power network, the existence of poorly damped low-frequency inter-area oscillations (LFIOs) has long affected stability constraints, and thereby, limited power transfer capacity. Adequate damping of inter-area modes is, thus, necessary to secure system operation and ensure system reliability while increasing power transfers. Power system stabilizers (PSS) is a prevalent means to enhance the damping of such modes. With the advent of phasor measurement units (PMUs), it is expected that wide-area damping control (WADC), that is, PSS control using wide-area measurements obtained from PMUs, would effectively improve damping performance in the Nordic grid, as well as other synchronous interconnected systems. Numerous research has investigated one ``branch'' of the problem, that is, PSS design using various control schemes. Before addressing the issue of controller design, it is important to focus on developing proper understanding of the ``root'' of the problem: system-wide oscillations, their nature, behavior and consequences. This understanding must provide new insight on the use of PMUs for feedback control of LFIOs. The aim of this thesis is, therefore, to lay important concepts necessary for the study of power system small signal stability analysis that considers the availability of synchrophasors as a solid foundation for further development and implementation of ideas and related applications. Particularly in this study, the focus is on the application addressed damping controller design and implementation. After a literature review on the important elements for wide-area damping control (WADC), the thesis continues with classical small signal stability analysis of an equivalent Nordic model; namely, the KTH-NORDIC32 which is used as a test system throughout the thesis. The system's inter-area oscillations are identified and a sensitivity analysis of the network variables directly measured by synchrophasors is evaluated. The concept of network modeshapes, which is used to relate the dynamical behavior of power systems to the features of inter-area modes, is elaborated. Furthermore, this network modeshape concept is used to determine dominant inter-area oscillation paths, the passageways containing the highest content of the inter-area oscillations. The dominant inter-area paths are illustrated with the test system. The degree of persistence of dominant paths in the study system is determined through contingency studies. The properties of the dominant paths are used to construct feedback signals as input to the PSS. Finally, to exemplify the use of the dominant inter-area path concept for damping control, the constructed feedback signals are implemented in a PSS modulating the AVR error signal of a generator on an equivalent two-area model, and compared with that of conventional speed signals.
|
|
| 5. |
- Chompoobutrgool, Yuwa, et al.
(författare)
-
Development and Implementation of the Nordic Grid Model for Power System Small-Signal and Transient Stability Studies in a Free and Open Source Software
- 2012
-
Ingår i: Power and Energy Society General Meeting, 2012 IEEE. - : IEEE. - 9781467327299 ; , s. 6344571-
-
Konferensbidrag (refereegranskat)abstract
- This article presents an implementation of a Nordic grid model in Power System Analysis Toolbox (PSAT) -a free and open-source software. A newly developed hydro turbine and hydro governor (HTG) model is implemented with this grid model and compared with the currently available PSAT turbine and governor models. Small-signal and transient stability analyses of the system using the two models are carried out and compared to demonstrate the difference and necessity of accurate hydro turbine and governor model utilization. The paper ends with a validation of the linearized Nordic grid model generated by PSAT including the newly implemented HTG models. This validation is done through nonlinear time-domain simulation by applying both large and small disturbances.
|
|
| 6. |
|
|
| 7. |
- Chompoobutrgool, Yuwa, et al.
(författare)
-
Identification of power system dominant inter-area oscillation paths
- 2013
-
Ingår i: IEEE Transactions on Power Systems. - 0885-8950 .- 1558-0679. ; 28:3, s. 2798-2807
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents three algorithms for identification of dominant inter-area oscillation paths: a series of interconnected corridors in which the highest content of the inter-area modes propagates through. The algorithms are developed to treat different sets of data: 1) known system model; 2) transient; and 3) ambient measurements from phasor measurement units (PMUs). These algorithms take feasibility into consideration by associating the network variables made available by PMUs, i.e., voltage and current phasors. All algorithms are demonstrated and implemented on a conceptualized Nordic Grid model. The results and comparison among three algorithms are provided. The applications of the algorithms not only facilitate in revealing critical corridors which are mostly stressed but also help in indicating relevant feedback input signals and inputs to mode meters which can be determined from the properties of dominant paths.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Chompoobutrgool, Yuwa, et al.
(författare)
-
On the persistence of dominant inter-area oscillation paths in large-scale power networks
- 2012
-
Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline) Volume 8, Issue PART 1, 2012. - : Elsevier BV. - 9783902823243 ; , s. 150-155
-
Konferensbidrag (refereegranskat)abstract
- This article discusses the degree of persistence of dominant inter-area oscillation paths: the passageways containing the highest content of inter-area oscillations in large-scale power networks. To this aim, a number of contingency studies are carried out: faults being imposed on the lines connecting to the dominant inter-area path. The path persistence is then examined using the relationship between sensitivities of network variables (i.e. voltages and current, magnitude and angle), and mode shapes describing the contribution of the oscillations among the generators variables (e.g. speed and angle). This relationship is termed network modeshape. The larger in magnitude and the lesser the variation the network modeshape is, the more observable and the more robust the signals measured from the dominant path becomes. The outcome is a proposed signal combination to be used as inputs to the damping controller for mitigation of inter-area oscillations in large-scale power systems.
|
|
| 11. |
- Chompoobutrgool, Yuwa, et al.
(författare)
-
Persistence of Multiple Interaction Paths for Individual Inter-Area Modes
- 2012
-
Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 9783902823243 ; , s. 14-19
-
Konferensbidrag (refereegranskat)abstract
- Dominant interaction paths are the passageways containing the highest modal content of particular oscillations in interconnected power systems. For the case of inter-area modes, pinpointing the dominant path that corresponds to each mode may allow for the extraction of signals that bear a significant modal content at a particular inter-area frequency. Strong modal content for these inter-area modes may also be spread onto secondary paths. These secondary paths bear similar properties as those shown by dominant paths. The aim of this study is thus to demonstrate the persistence of both dominant and secondary paths by employing “network modeshape” properties. The existence of the paths is verified by nonlinear time-domain simulations where modal content at each inter-area frequency is extracted. The proper selection of feedback signals from the dominating paths may increase the flexibility of WAPODs by providing a number of signal choices to be used as backup in the presence of contingencies.
|
|
| 12. |
- Chompoobutrgool, Yuwa, 1984-, et al.
(författare)
-
Survey on Power System Stabilizers Control and their Prospective Applications for Power System Damping using Synchrophasor-Based Wide-Area Systems
- 2011
-
Ingår i: European transactions on electrical power. - : John Wiley & Sons. - 1430-144X .- 1546-3109. ; 21:8, s. 2098-2111
-
Tidskriftsartikel (refereegranskat)abstract
- Powersystemoscillationdampingremains as one of the major concerns for secure and reliable operation of largepowersystems, and is of great current interest to both industry and academia. The principal reason for this is that the inception of poorly-damped low-frequency inter-areaoscillations (LFIOs) whenpowersystemsare operating under stringent conditions may lead tosystem-widebreakups or considerably reduce thepowertransfers over critical corridors. With the availability of high-sampling rate phasor measurement units (PMUs), there is an increasing interest for effectively exploiting conventionaldampingcontroldevices, such aspowersystemstabilizers(PSSs), by using these measurements ascontrolinput signals. In this paper, we provide a comprehensive overview of distinct elements (or "building blocks") necessary forwide-areapowersystemdampingusing synchrophasors and PSSs. These building blocks together shape a tentative methodical framework, and are disposed as follows: (1) fundamental understanding of the main characteristics of inter-areaoscillations, (2)wide-areameasurement andcontrolsystems(WAMS and WACS) andwide-areadampingcontrol(WADC), (3) advanced signal processing techniques for mode property identification, (4) methods for model-basedsmall-signal analysis, (5)controlinput signals selection, and (6) methods for PSScontroldesign. We also describe the latest developments in the implementation ofsynchrophasormeasurements in WAMS and WACS as well as their prospectives for WADCapplications. This paper serves both to abridge the state-of-the-art in each of these elements, and to accentuate aspiring ideas in each building block.
|
|
| 13. |
- Chompoobutrgool, Yuwa, et al.
(författare)
-
Using PMU signals from dominant paths in power system wide-area damping control
- 2015
-
Ingår i: Sustainable Energy, Grids and Networks. - : Elsevier. - 2352-4677. ; 4, s. 16-28
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents a comprehensive study of dominant inter-area oscillation path signals and their application for power system wide-area damping control (WADC). The analysis, carried out on both small and large study systems, focuses on the relationships that emerge from physical characteristics of inter-area oscillations, namely the modal observability of signals from dominant paths and their corresponding control loop system properties (i.e. stability and robustness). The aim is to be able to appropriately exploit the dominant path signals for the mitigation of inter-area oscillations. Guidelines and considerations are provided to facilitate the design of WADC using the proposed approach.
|
|
| 14. |
- Danielson, Magnus, et al.
(författare)
-
Analysis of Communication Network Challenges for Synchrophasor-Based Wide-Area Applications
- 2013
-
Ingår i: Proceedings of IREP Symposium. - : IEEE conference proceedings. - 9781479901999
-
Konferensbidrag (refereegranskat)abstract
- Wide-area synchrophasor applications inherently depend on the underlying IT and communications infrastructure supporting them. In particular, closed loop control systems for power grid oscillation damping is problematic, as it is a complex mixture of power grid monitoring, communication network properties and overall system stability issues. This article offers a holistic analysis of these fields, proposing a combined requirement on the full system: to keep system delays down to maintain stability. Simulation results to support the analysis findings, also showing how observability of power oscillations is important in combination with system delays related to feedback signals, and finally laying out experimentation plans to be performed in the lab on a complex power-grid model with real PMUs, communication network and controllers interacting with the SmarTS Lab real-time hardware-in-the-loop simulator platform.
|
|
| 15. |
- Li, Wei, et al.
(författare)
-
Development and implementation of hydro turbine and governor models in a free and open source software package
- 2012
-
Ingår i: Simulation (San Diego, Calif.). - : Elsevier BV. - 1569-190X .- 1878-1462. ; 24, s. 84-102
-
Tidskriftsartikel (refereegranskat)abstract
- This article studies accurate and detailed hydro turbine and governor models, and implements these models in Power System Analysis Toolbox (PSAT)-a free and open source software. The implementation of these models in PSAT is approached using a general methodology, which is described in detail. To evaluate the performances of the developed hydro turbine and governor models, simulation studies are carried out on test systems of different scales, from a single-machine infinite-bus (SMIB) system to a larger system which includes 20 generators. Further more, transient stability analysis and small signal stability analysis are carried out to assess the performance of the implemented models.
|
|
| 16. |
|
|
| 17. |
- Sturk, Christopher, et al.
(författare)
-
Coherency-Independent Structured Model Reduction of Power Systems
- 2014
-
Ingår i: IEEE Transactions on Power Systems. - 0885-8950 .- 1558-0679. ; 29:5, s. 2418-2426
-
Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a new model reduction algorithm for power systems based on an extension of balanced truncation. The algorithm is applicable to power systems which are divided into a study area which requires a high-fidelity model and an external area, making up most of the power system, which is to be reduced. The division of the power system can be made arbitrarily and does not rely on the identification of coherent generators. The proposed algorithm yields a reduced order system with a full non-linear description of the study area and a reduced linear model of the external area.
|
|
| 18. |
- Sturk, Christopher, et al.
(författare)
-
Structured Power System Model Reduction of Non-Coherent Areas
- 2012
-
Ingår i: Power and Energy Society General Meeting, 2012 IEEE. - : IEEE. - 9781467327275 ; , s. 6344913-
-
Konferensbidrag (refereegranskat)abstract
- This paper demonstrates how structured model reduction can be used to reduce the order of power systems without the need to identify coherent groups of generators. To this end the Klein-Rogers-Kundur 2-area system is studied in detail. It is shown how different modes of the system are captured as the model order is varied, which is of interest in e.g. distributed controller design, where the objective is to damp these oscillations. The power system is divided into a study area and an external area and the proposed algorithm is used to reduce the external area to a low order linear system, while retaining the nonlinear description of the study area. It is shown that this approach permits greater deviations from the steady-state than if a reduced system that is entirely linear is used, while still yielding accurate simulation results.
|
|
| 19. |
- Vanfretti, Luigi, 1981-, et al.
(författare)
-
Interarea Mode Analysis for Large Power Systems using Synchrophasor Data
- 2013
-
Ingår i: Power System Coherency and Model Reduction. - New York : Springer. - 9781461418023 - 9781461418030 ; , s. 259-295
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Interarea oscillations are predominantly governed by the slower electromechanical modes which, in turn, are determined by the coherent machine rotor angles and speeds. The issue is that, although these rotor angles and speeds provide the best visibility of such modes, currently they are not available from phasor measurement units (PMU). As such, the aim of this chapter is to demonstrate that interarea oscillations are observable in the network variables, such as voltages and line currents, which are measured by PMU. By analyzing the electromechanical modes in the network variables, we can trace how electromechanical oscillations are spread through the power network following a disturbance. Applying eigenvalue and sensi- tivity analysis, we provide an analytical framework to understand the nature of these network oscillations through a relationship termed network modeshapes. Using this relationship, a novel concept, “dominant interarea oscillation paths,” is developed to identify the passageways where the interarea modes of concern travel the most. We demonstrate the concept of the dominant path with an equivalent two-area sys- tem. We propose an algorithm for identification of the dominant paths and illustrate with a reduced model of a large-scale network. Finally, we end this chapter with an important application of the concept: feedback input signal selection for damping controller design.
|
|
