STATCOM and Flexible DC Coordinated Control Strategies for Improving the Stability of Hybrid Multi-infeed HVDC Operation

A voltage source converter based high voltage direct current (VSC-HVDC) in a hybrid multi-infeed high voltage direct current (HMIDC) system can realize the four-quadrant power operation. The reactive power control of VSC-HVDC can maintain stable operation of the AC bus voltage. A fault in the receiving AC system results in a significant voltage drop in the receiving bus, which will cause line commutated converter-based high voltage direct current (LCC-HVDC) continuous commutation failure. A static synchronous compensator (STATCOM) and VSC-HVDC reactive power coordination control strategy is proposed. The principle of STATCOM reactive power control is analyzed. Then, the HMIDC system with STATCOM is established. The coordinated control strategy and electrical parameters of the HMIDC system with STATCOM are designed. The effectiveness of the proposed coordinated power control strategy is verified by simulation results.