Indirect voltage control method for single phase DC/AC converters

A controller for single phase DC/AC converters is proposed that is analogous with the droop control method used in synchronous generator technology. Its approach is different from the existing droop techniques adopted for power electronic inverters where consistently the output voltage is controlled through an explicit voltage control loop. The proposed method indirectly controls the output voltage of the inverter by controlling its immediate (or internal) voltage. Therefore, when operating in parallel with other inverters, it can offer a more robust and stable operation by avoiding direct competition of the inverters. This paper presents the derivations and numerical results of the proposed controller.