基于双闭环电压控制静止同步补偿器在双馈风电场并网中参数设置及运行特性分析

Analysis of parameter setting and operation characteristics on DFIG-based wind farm integration with STATCOM based on dual- loop voltage control

静止同步补偿器(STATCOM)在柔性功率潮流控制及双馈风电场并网运行中得到广泛分析与讨论,而其双闭环电压控制策略的分析直接影响风电场并网运行特性。建立了基于电压源变流器(VSC)的静止同步补偿器通过耦合变压器与电网相连的电路模型,推导了双闭环电压控制环节的数学模型,分析了控制环节参数设置对于并网运行特性的影响。以标准三机九节点系统作为等效测试电网建立了双馈风电场并网模型,实例中以控制环节参数设置验证了衰减系数与电压设定值与无功控制的对应关系,以负荷投切小扰动为例分析了投入装置可以改善系统受扰动时的电能质量,并且通过不同类型的故障仿真验证了即使电力系统发生了最严重的三相短路故障,STATCOM也能快速补偿无功功率,有效提高系统的暂态稳定性。

STATCOM has been widely analyzed and discussed in flexible power flow control and operation of DFIG- based wind farm integration. Analysis on its dual-loop voltage control strategy directly affects the operation characteris- tics of wind farm integration. Firstly, a circuit model of STATCOM based on VSC, which is connected to power grid through coupling transformer is built. Then, the mathematical model of dual-loop voltage control link is derived and the impact of parameter in control link on integration operation characteristics is analyzed. Finally, a model of DFIG- based wind farm integration is established, which is using the three-machine nine-bus system as the equivalent power grid. Simulation results show that the corresponding relationship between the droop coefficient and reactive power and the power quality can be improved by using STATCOM. And through different types of fault simulation, it shows that the STATCOM can compensate reactive power quickly and improve transient stability of power system effectively even if there is the most serious three - phase short circuit fault.