Novel control design and strategy for load frequency control in restructured power systems

In restructured electric power systems, a number of generation companies and independent power producers compete in the energy market to make a profit. Furthermore, a new marketplace for ancillary services is established, providing an additional profit opportunity for those power suppliers. These services are essential since they help support the transmission of power from energy sources to loads, and maintain reliable operation of the overall system. This dissertation addresses regulation , a major ancillary service also known as the load frequency control (LFC) problem, and presents novel control designs and strategies for the LFC in restructured power systems.;A power system is an interconnection of control areas, which are operated according to control performance standards established by the North American Electric Reliability Council (NERC). LFC is a necessary mechanism in each control area because it maintains a balance between power demand and power generation while assuring compliance with NERC standards.;This dissertation first develops three new control designs that yield effective and robust load frequency control actions. All controllers developed here require only local measurements. The first control design is based on decoupling each area thru modeling of the interconnection effects of other control areas. The second control design relies on the robust H infinity theory in terms of linear matrix inequalities (LMIs). The third control design is achieved by the collaboration between genetic algorithms (GAs) and LMIs. The first two control designs result in high-order dynamic controllers. The third design requires only a simple proportional-integral (PI) controller while yielding control performance as good as those resulting from the previous two designs. Consequently, the third control design is the most preferable due to its simplicity and suitability for industry practice. Furthermore, a stability analysis method based on perturbation theory of eigenvalues is developed to assess the stability of the entire power system being equipped by the proposed controllers.;Second, to comply with NERC standards, two LFC strategies are developed to direct LFC\u27s actions. One strategy employs fuzzy logic to mimic a skillful operator\u27s actions so that all decisions are made efficiently. The other strategy treats the compliance with NERC standards as constraints while minimizing the operational and maintenance costs associated with LFC actions. Three new indices are introduced to assess economic benefits from the strategy compared to the conventional methods. Simulation is performed to demonstrate performances of all proposed methods and strategies

Field analysis and design of a moving iron linear alternator for use with linear engine

The previous research at West Virginia University has developed a permanent magnet linear alternator and linear combustion engine for testing and studying the performance. In this prototype, magnets are part of the moving part.;This research will present a new type of linear alternator with permanent magnets installed on stationary called Moving Iron Linear Alternator (MILA). MILA offers several advantages over other types such as rugged structure, and low cost production. First, MILA will be designed for use with the existing linear engine. An optimization methodology will be applied to obtain optimal design parameters. Next, a MILA model will be created in EMAS, field analysis software, to determine the machine flux. Later, the simulation will be performed for calculating the back emf and current of MILA. Finally, the simulation results will be discussed and explanations will be given

Field Analysis and Design of a Moving Iron Linear Alternator for Use with Linear Engine

magnet linear alternator and linear combustion engine for testing and studying the performance. In this prototype, magnets are part of the moving part. This research will present a new type of linear alternator with permanent magnets installed on stationary called Moving Iron Linear Alternator (MILA). MILA offers several advantages over other types such as rugged structure, and low cost production. First, MILA will be designed for use with the existing linear engine. An optimization methodology will be applied to obtain optimal design parameters. Next, a MILA model will be created in EMAS, field analysis software, to determine the machine flux. Later, the simulation will be performed for calculating the back emf and current of MILA. Finally, the simulation results will be discussed and explanations will be given. ACKNOWLEDGEMENTS I would like to express my sincere appreciation to my research advisor, Dr. Parviz Famouri, for his guidance and encouragement throughout this research. I would like to thank Dr. Muhammad A. Choudhry and Dr. Wils L. Cooley for serving on my examining committee and for their valuable suggestions

Energy storage system control strategies for power distribution systems

Energy storage systems have been widely employed to attain several benefits, such as reliability improvement, stabilization of power systems connected with renewable energy resources, economic benefits and etc. To achieve the above objectives, the appropriate and effective control strategies for energy storage systems are needed to be developed. This research proposes energy storage system control strategies for power distribution systems equipped with a limited size of energy storage system in order to improve reliability and save energy costs by determining an optimal charging schedule of the energy storage system. Simulation results demonstrate the benefits of energy storage system applications under the different control strategies

Optimal Preventive Maintenance Planning for Electric Power Distribution Systems Using Failure Rates and Game Theory

Current electric utilities must achieve reliability enhancement of considerable distribution feeders with an economical budget. Thus, optimal preventive maintenance planning is required to balance the benefits and costs of maintenance programs. In this research, the proposed method determines the time-varying failure rate of each feeder to evaluate the likelihood of future interruptions. Meanwhile, the consequences of feeder interruptions are estimated using interruption energy rates, customer-minutes of interruption, and total kVA of service areas. Then, the risk is assessed and later treated as an opportunity for mitigating the customer interruption costs by planned preventive maintenance tasks. Subsequently, cooperative game theory is exploited in the proposed method to locate a decent balance between the benefits of reliability enhancement and the costs required for preventive maintenance programs. The effectiveness of the proposed method is illustrated through case studies of large power distribution networks of 12 service regions, including 3558 medium-voltage distribution feeders. The preventive maintenance plans resulting from the proposed method present the best compromise of benefits and costs compared with the conventional approach that requires a pre-specified maintenance budget

Optimal Preventive Maintenance Planning for Electric Power Distribution Systems Using Failure Rates and Game Theory

Current electric utilities must achieve reliability enhancement of considerable distribution feeders with an economical budget. Thus, optimal preventive maintenance planning is required to balance the benefits and costs of maintenance programs. In this research, the proposed method determines the time-varying failure rate of each feeder to evaluate the likelihood of future interruptions. Meanwhile, the consequences of feeder interruptions are estimated using interruption energy rates, customer-minutes of interruption, and total kVA of service areas. Then, the risk is assessed and later treated as an opportunity for mitigating the customer interruption costs by planned preventive maintenance tasks. Subsequently, cooperative game theory is exploited in the proposed method to locate a decent balance between the benefits of reliability enhancement and the costs required for preventive maintenance programs. The effectiveness of the proposed method is illustrated through case studies of large power distribution networks of 12 service regions, including 3558 medium-voltage distribution feeders. The preventive maintenance plans resulting from the proposed method present the best compromise of benefits and costs compared with the conventional approach that requires a pre-specified maintenance budget