同步调相机对受端省级电网运行影响及控制策略研究

Research on synchronous condenser’s influences on receiving-end provincial grid and its control strategy

同步调相机作为特高压直流配套工程投产后,开展其对受端电网运行影响以及协调控制策略研究具有重要现实意义。首先分析了大型同步调相机的无功运行特性,建立了不同时间尺度下的调相机无功电压模型。其次通过华东实际电网算例,仿真分析了对电压特性、短路电流以及换相失败等的影响。仿真结果表明,调相机接入后可以有效提升电压支撑能力,显著增强电网强度,降低换相失败风险,验证了理论分析的正确性。最后提出将调相机接入AVC统一调配,并采用较小静态调差系数和稳态迟相运行的控制策略,可充分发挥调相机的动态无功支撑作用。

After synchronous condenser being put into operation as the match project of UHVDC transmission, it’s reasonable to investigate its influence on the operation of large-scale AC-DC hybrid grids, as well as explore its control strategy. Firstly, this paper researches the reactive power characteristics of condenser and builds its reactive power supporting models for different time scales. Secondly, simulations are carried out with the East China Power Grid, the condenser’s influences on voltage characteristics, short-circuit current and commutation failure characteristics are analyzed. The result reveals that condenser could considerably enhance the voltage supporting capability, improve the power grid strength and decrease the risk of UHVDC commutation failure. The validity of theoretical analysis is also verified by the simulation. Finally, a unified dispatch strategy which adopts small difference coefficients and steady lagging-phase operation is proposed for integrating the condenser into AVC system. By adopting the proposed strategy, condenser’s dynamic reactive power supporting function can be sufficiently utilized.