Research on key technologies of high voltage and large capacity static synchronous series compensator control system

Abstract

With the rapid development of economy, the structure of power grid is becoming more and more complex, which has brought about uneven distribution of power flow, limited transmission capacity and the decline of power quality. The application of new static synchronous series compensator can quickly and effectively regulate power flow, suppress sub-synchronous oscillation and enhance system stability on the basis of guaranteeing transmission capacity. In practical engineering application, the design of control system and the realization of control algorithm are very important. In this paper, the control system of 220 kV 30MW self-excited SSSC device is developed based on the control and protection platform of serial RapidIO technology. Firstly, the main topology structure of SSSC is introduced, and the two-stage DC voltage stabilization and upper steady-state operation control strategy of SSSC using fast response control method which simultaneously regulates modulation ratio and trigger angle are expounded. Secondly, the dual redundancy control system architecture is designed, and the control system implementation scheme is designed. Finally, the RTDS power in the loop experimental system is designed, and the control algorithm is verified by RTDS experiments. The experimental results show that the control strategy and control system implementation scheme adopted in this paper can realize smooth start-up and exit of SSSC device and flexible regulation of power flow. The developed control system can satisfy the long-term reliable and stable operation of the system, especially the design of redundancy mechanism, and increase the reliability of the device operation. Follow-up static synchronous series compensator project and even FACTS project provide reference.