Abstract
As the structure of the power system changes day by day, the penetra- tion of distributed generation units increases in microgrids, and the power supply can not meet the demand. Thus, the power system stability has been faced with a lot of challenges. Therefore, the importance of Flexible AC Transmission System (FACTS) can not be ignored nowadays. One of the members, Static Synchronous Compensator (STATCOM), is a potential so- lution to improve the power system stability. In the thesis, the basic structure and control strategies of a Voltage- Sourced Converter (VSC) system are investigated at first. Through the fre- quency loop shaping method, the compensator is properly designed. Based on the synchronous reference frame theory, the compensator of Phase-Locked Loop (PLL) is designed in order to track the grid voltage. It can reduce the complexity of the control the three-phase VSC system. Then, the control and functionalities of STATCOM are studied, and the passivity-based con- trol (PBC) method is introduced in order to compare with the conventional STATCOM control method. Because it is difficult to test the STATCOM with a real power system, the real-time simulation platform is built in or- der to interface the STATCOM with a virtual grid, which likes a real one. Also, the Real-Time Simulator (RTS) is used as a controller to control the real converter, which is known as Hardware-in-the-Loop (HIL). The sim- ulation procedure is proposed to verify the feasibility of the STATCOM control.