摘要: As a long-distance transmission system, Sichuan system has an undesirable power flow distribution, which has seriously infringed on its security. In order to improve its stability, a dynamic model considering external disturbances... 展开 As a long-distance transmission system, Sichuan system has an undesirable power flow distribution, which has seriously infringed on its security. In order to improve its stability, a dynamic model considering external disturbances is proposed. Then based on PWM technology, a novel hybrid control strategy for UPFC is built. A nonlinear H_∞ law is designed for control phase of the series converter. While for the other three control variables (modulation ratios and control phase), conventional PI control is adopted. Furthermore, based completely on the locally measurable variables, the proposed controller could be very practical. Simulation studies have verified its effectiveness to improve the dynamic quality and transient stability of Sichuan system. 收起