Modeling, Simulation, and Control of a Medium-Scale Power System

verfasst von: Tharangika Bambaravanage, Dr. Asanka Rodrigo, Prof. Sisil Kumarawadu

Verlag: Springer Singapore

Buchreihe : Power Systems

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

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Über dieses Buch

This book highlights the most important aspects of mathematical modeling, computer simulation, and control of medium-scale power systems. It discusses a number of practical examples based on Sri Lanka’s power system, one characterized by comparatively high degrees of variability and uncertainty. Recently introduced concepts such as controlled disintegration to maintain grid stability are discussed and studied using simulations of practical scenarios.
Power systems are complex, geographically distributed, dynamical systems with numerous interconnections between neighboring systems. Further, they often comprise a generation mix that includes hydro, thermal, combined cycle, and intermittent renewable plants, as well as considerably extended transmission lines. Hence, the detailed analysis of their transient behaviors in the presence of disturbances is both highly theory-intensive and challenging in practice. Effectively regulating and controlling power system behavior to ensure consistent service quality and transient stability requires the use of various schemes and systems.
The book’s initial chapters detail the fundamentals of power systems; in turn, system modeling and simulation results using Power Systems Computer Aided Design/Electromagnetic Transients including DC (PSCAD/EMTDC) software are presented and compared with available real-world data. Lastly, the book uses computer simulation studies under a variety of practical contingency scenarios to compare several under-frequency load-shedding schemes. Given the breadth and depth of its coverage, it offers a truly unique resource on the management of medium-scale power systems.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract

This chapter highlights the importance of maintaining the quality and reliability of a power system. Types of disturbances that may lead the power system unstable and effects due to the instability situations are briefly explained.

Tharangika Bambaravanage, Asanka Rodrigo, Sisil Kumarawadu

Chapter 2. Literature Survey

Abstract

This chapter gives a clear idea about what is meant by a power system and its behaviour under different electrical and mechanical variations in power system components. Reasons for occurring power system instability situations, their effects on the power system in-turn are highlighted. In order to maintain a quality and reliable power supply through Primary, Secondary and Tertiary control these instability situations due to perturbations in a medium size power system can be effectively addressed and it is broadly discussed. The first few seconds of frequency degradation and recovery after a major generator trip is essentially be accomplished by governor control. When the power system’s self-regulation is insufficient to establish a stable state, the system frequency will continue to drop until it is arrested by automatic under-frequency load shedding to re-establish the load-generation balance within the time constraints necessary to avoid system collapse. Different suggestions for Under Frequency Load Shedding to maintain stability of the power system by various researchers are also high-lighted and reviewed in this chapter.

Tharangika Bambaravanage, Asanka Rodrigo, Sisil Kumarawadu

Chapter 3. Modelling the Power System

Abstract

To study the stability and to observe how the power system behaves, during normal and abnormal conditions, availability of a simulation model of the considering Power System is very important. It is very important to ascertain that the simulation model’s performance is identical or approximately equal to the corresponding real time power system’s behavior. Since one of the aims of this research is to address frequency degradation due to Generation—Load imbalance situations in Sri Lanka, it has been decided to simulate the power system of Sri Lanka. Convenience of collecting required data from the Ceylon Electricity Board (the only utility available in Sri Lanka) on request, was an added advantage. Therefore a simulation model of the Power System of Sri Lanka (Transmission network—132 and 220 kV) was designed using the software PSCAD/EMTDC. All basic components of the transmission network such as synchronous generators, transformers, transmission lines, under-ground cables, governors, turbines etc. were simulated with their real time values.

Tharangika Bambaravanage, Asanka Rodrigo, Sisil Kumarawadu

Chapter 4. Designing the Load Shedding Scheme

Abstract

It is very important to have a clear idea about the power system we are concerning on to understand the necessity of a load shedding scheme. The parameters and their values that we use in the under frequency load shedding scheme influence in stabilizing the power system very much. The proposed load shedding scheme was designed referring to Ahsans’ scheme as a pilot model. Having identified the weaknesses with it the new load shedding schemes are proposed.

Tharangika Bambaravanage, Asanka Rodrigo, Sisil Kumarawadu

Chapter 5. Results and Discussion

Abstract

Validity of the proposed load shedding schemes was carried out by simulating them in the designed power system simulation model under different scenarios (generation deficits) and compare their results with that of the current Ceylon Electricity Board’s (CEB’s) Load Shedding scheme. With the prevailing facilities with the CEB, the proposed load shedding scheme-I can be implemented more effectively than that of CEB. With the proposed load shedding scheme-II that leads for disintegration of the power system can cater more consumers than the previous Load shedding schemes while maintaining the stability of islands concerned as well as the national grid. The simulation results show that if the frequency of the last stage of the Load Shedding Scheme can be set at 48.6 Hz, the power system could be brought to a stable condition (while maintaining frequency and voltage within limits). That is, the power system frequency will not go below 47.0 Hz (f > 47 Hz) which is critical with thermal generators.

Tharangika Bambaravanage, Asanka Rodrigo, Sisil Kumarawadu

Chapter 6. Conclusion

Abstract

This research was carried out based on a model of the power system of Sri Lanka, which was simulated suing PSCAD EMTDC and COMFORTRAN software. This power system simulation was done with reference to the load flow occurred on the 13th May, 2013 as the day-time peak demand (around 12.30 p.m.). Different actual power system scenarios were simulated in this model and its results/performance was very much closer to real time values. But as I see, following are some points that should be accounted for, through which the performance of the simulation model could have been improved further.

Tharangika Bambaravanage, Asanka Rodrigo, Sisil Kumarawadu

Backmatter

Titel: Modeling, Simulation, and Control of a Medium-Scale Power System
verfasst von: Tharangika Bambaravanage
Dr. Asanka Rodrigo
Prof. Sisil Kumarawadu
Verlag: Springer Singapore
Electronic ISBN: 978-981-10-4910-1
Print ISBN: 978-981-10-4909-5
DOI: https://doi.org/10.1007/978-981-10-4910-1