Abstract
The present invention relates to a load impedance estimation and iterative learning control method capable of allowing inductance variation for inverter, wherein the method is applied for predicting the next duty cycles for four power switching sets of the inverter by way of accomplishing the real-time sampling of three phase voltages and calculating next-period voltage compensation according to the previous-period voltage compensation. Moreover, the method also involves the inductance variation of the output inductors into the load impedance-estimating matrix equation during the load impedance prediction. By the application of this method, the inverter with four wires and three phases is able to provide a steady output voltage to the loads even if the originally-connected loads are replaced by other different loads. Therefore, this load impedance estimation and iterative learning control method can indeed solve the drawbacks produced by the conventional SVPWM method.