SVG协同风电场的电网电压稳定控制策略研究

Study on voltage stability control strategy of power grid with SVG coordinated wind farm

针对含风电场及SVG的电网因外部因素引起的电压偏差和波动问题,提出一种利用SVG和DFIG风电场协同控制电压的综合策略。根据监测点的电压波动,在电压骤升骤降时,通过PI控制和逻辑选择对SVG及DFIG进行控制,给出了整个调节系统的框架和流程。充分利用SVG调节无功的快速性,优先使用SVG输出无功功率对监测点电压进行支撑;如果超出了SVG的调节能力,在保证风电机组满足规定的功率因数前提下再调节风电机组进行无功输出,最终实现稳定监测点电压的目标。在检测到电压稳定后,还需要对无功分配情况进行合理性判别,对存在的不利情况进行无功重分配,避免不必要的无功流动,提高风电接入后电网的运行稳定性。

In order to solve the problem of voltage deviation and fluctuation caused by external factors in power grid including wind farm and SVG,a comprehensive strategy of voltage coordinated control by using SVG and DFIG wind farm is proposed.According to the voltage fluctuation of the monitoring point,the SVG and DFIG are controlled by PI control and logic selection when the voltage suddenly rises or falls,and the framework and process of the whole regulating system are given.By making full use of the rapidity of SVG in regulating reactive power,SVG is preferentially used to output reactive power to support the voltage at the monitoring point.If the regulation capacity of SVG is exceeded,the DFIG is controlled to output reactive power under the premise that the DFIG meets the specified power factor,and finally the voltage support for the monitoring point is realized.After the voltage stability is detected,it is also necessary to judge the rationality of reactive power distribution and redistribute reactive power under the existing adverse conditions to avoid unnecessary reactive power flow,which improves the operation stability of the grid after the wind farm is connected.