中文说明：资源描述利用pi滞还跟踪，电网电压，可以使用户侧功率因素达到0.99以上，即实现用户电流与电网电压流形同相位。
English Description：
Application backgroundUsing PI hysteresis tracking, grid voltage, can be used to achieve more than 0.99 of the user side power factor, that is, to achieve the user current and grid voltage manifold with the same phase.