EEAC-Based Emergency Power Support Strategy for Improving Total Transmission Capacity of Multiple HVDC Links

In modern power system, HVDC links with desirable adaptability can provide emergency power support to improve transmission capacity in risky situations. Traditional emergency DC power support (EDCPS) methods for transmission capacity enhancement heavily rely on domain expertise for parameter tuning, which is lack of theoretical foundation. Focusing on sending-end power systems with multiple HVDC links for renewable energy delivery, this paper develops an extended equal-area criterion (EEAC)-based emergency power support approach to improve the total transmission capacity (TTC). Firstly, a TTC estimation method is introduced to help reliably quantify the power transfer limit. Then, an index is proposed to evaluate the effectiveness of EDCPS based on EEAC, laying a solid foundation for the design of EDCPS strategy. Further, an EDCPS strategy is developed to enhance the stability of the whole system and increase the TTC of multiple HVDC links. Finally, case studies on a realistic sending-end system demonstrate the effectiveness of the proposed EDCPS approach.