Vector control of the single-phase inverter based on the extended and virtual circuits

A vector control based on the extended equivalent circuit and virtual circuits is proposed for the single-phase inverter. By the extended circuit, the other two phase voltages can be extended by the output voltage of the single-phase inverter so as to construct the voltage vector. The voltage outer-loop is to control the voltage vector in dq coordinate system, and the output voltage can track the target value without deviation in steady state. By designing the virtual circuit, the voltage inner-loop can achieve approximate decoupling and improve the dynamic response under the changeable load. Compared with the traditional dual closed-loop control, the proposed dual closed-loop control scheme only needs to detect and control the voltage without the current. It not only can achieve good control effect, but also reduce the complexity of the hardware. Finally, the simulation and experimental results show that the single-phase inverter has good static and dynamic characteristics regardless of stable load or changeable load.