直流有功恢复速率对送端系统功角稳定的影响分析

Influence Mechanism Analysis of the Active Power Recovery Rate of HVDC on the Rotor Angle Stability of the Sending-end System

特高压直流输电已成为中国大型能源基地电能外送的主要措施,研究故障清除后直流有功恢复速率对系统功角稳定性的影响具有重要意义。该文从数学上推导直流有功恢复速率对同步机电磁功率的影响;基于等面积定则理论分析不同直流有功恢复速率下,同步机减速面积的变化特性;并进一步研究同步机等值内阻变化对功角稳定性的影响;最后通过典型系统和实际系统验证了理论分析的正确性。文中的分析为特高压交直流外送系统功角稳定控制提供了参考。

At present, electrical power transmitted by ultra-high voltage direct current(UHVDC) has become the main choice of large-scale renewable energy bases in China. It is significant to analyze the active power recovery rate of UHVDC after the short-circuit fault is cleared on the rotor angle stability of the sending-end system. In this paper, the influence of active power recovery rate of HVDC after fault cleared on the electrical power of the synchronous generator(SG) was deduced mathematically. Based on the equal-area criterion(EAC), the variation characteristics of deceleration area of the SG with the increase of active power recovery rate of HVDC were analyzed. Furthermore, the impact of equivalent internal reactance of the SG on the rotor angle stability of the sending-end system was analyzed. Finally, the theoretical analysis was validated by the typical actual HVDC system in in China’s Northwest Power Grid. The analysis in this paper provides theoretical foundation and reference for the rotor angle stability control strategy of HVDC transmission system.