Theses and Dissertations Collection

With the advent of power electronic converter-based generation technology in the power utility industry, there is an increasing need for sources of dynamically controllable real and reactive power to maintain stability of electric power systems. Static Synchronous Compensators (STATCOMs) improve the stability of electric power systems by dynamically controlling reactive power supply to the system. However, they cannot provide dynamic real power control. In this dissertation, a device capable of both dynamic real power and reactive power control is presented. The device consists of a modular multilevel converter (MMC) -based STATCOM combined with a hybrid energy storage system that combines a battery energy storage with a supercapacitor energy storage system. Matlab/Simulink is utilized to examine the stability of the response of an electric transmission system under fault conditions without compensation, with a STATCOM alone and with the enhanced energy storage system. Simulation plots show that the system stability improves significantly when the hybrid energy storage system is combined with the STATCOM for dynamic real and reactive power compensation.