伊冯/呼辽交直流系统的次同步振荡阻尼特性分析

Analysis on Damping Characteristic of Subsynchronous Oscillation in AC/DC Power Grid Consisting of 500 kV AC Power Transmission From Yimin to Fengtun and ±500 kV DC Power Transmission From Hulun Buir to Liaoning

建立了基于伊冯/呼辽交直流系统的电磁暂态模型,采用基于时域仿真实现的复转矩系数法——测试信号法,对机组施加了一系列不同频率的测试信号。计算了不同连接方式下机组在次同步频率范围内的电气阻尼特性,并考察了可控串联补偿装置对该阻尼特性的影响。最后结合时域仿真法验证了测试信号法分析结果的有效性。理论分析和仿真结果表明,在交直流系统中采用联网运行带可控串补的方式,有利于抑制高压直流输电系统和交流输电线路中串补装置引起的次同步振荡问题。

An electromagnetic transient model for AC/DC power grid consisting of 500 kV AC power transmission from Yimin to Fengtun and ±500 kV DC power transmission from Hulun Buir to Liaoning is built, and adopting the complex torque coefficient method-test signal method that is implemented by time-domain simulation a series of testing signals with different frequencies are applied to generation units. Generation units’ electrical damping characteristics within the frequency range of subsynchronous oscillation （SSO） under different wiring patterns are calculated, and the influence of TCSC on the damping characteristics is observed. Based on time-domain simulation, the effectiveness of analysis results by test signal method is verified. Both results from theoretical analysis and experimental verification show that in AC/DC power grid the connected operation of DC power system with AC power system is favorable to mitigate SSO caused by HVDC power transmission system and serial compensation equipments in AC power transmission system.