Filter capacitor current sensor-free control device of three-phase DC-AC converter

The invention provides a filter capacitor current sensor-free control device for a three-phase DC-AC converter by using a state observer. The method comprises following steps: at a current sampling time, receiving one DC chain voltage of a three-phase DC-AC converter; at a current sampling time, receiving one first phase filter capacitor voltage actual value, one second phase filter capacitor voltage actual value, and one third phase filter capacitor voltage actual value; through one state observer, outputting one filter capacitor current state variable, which is a predicted current value of anext sampling time and is an average current value that does not contain any ripple. 本发明提供了一种状态观察器用于三相直交流转换器的滤波电容电流无传感器控制方法，包含：接收当前取样时间下，该三相直交流转换器的一直流链电压；接收该当前取样时间下，该三相直交流转换器的一第一相滤波电容电压实际值、一第二相滤波电容电压实际值、以及一第三相滤波电容电压实际值；以及藉由一状态观察器，输出滤波电容电流状态变量，该滤波电容电流状态变量为下一取样时间的一电流预测值，且该滤波电容电流状态变量为无涟波的一平均电流值。