Three-phase energy storage converter stability control method and system under serious short-circuit fault of power grid

The invention discloses a stable control method and system for a three-phase energy storage converter under a serious short-circuit fault of a power grid, and the interference resistance of an energy storage converter system is enhanced by converting a control mode. When the power grid has a serious short-circuit fault, control is switched to direct given fault active and reactive current control, certain reactive current is provided, and the voltage of a grid-connected point is supported. And according to the voltage drop degree of the power grid and the phase-locked loop switching control mode, the number of system intersections after a fault is increased, and the transient stability of the energy storage converter is improved. 本发明公开了一种电网严重短路故障下三相储能变流器稳定控制方法及系统，通过转换控制模式，增强了储能变流器系统抵抗干扰的能力。电网严重短路故障时，控制切换至直接给定故障有功、无功电流控制，提供一定的无功电流，支撑并网点电压。根据电网电压跌落程度，锁相环切换控制模式，增加故障后系统交点个数，提高储能变流器暂态稳定性。