Control of a 4 leg inverter for standalone photovoltaic systems

The control of a four leg inverter for standalone photovoltaic systems must provide symmetrical three phase voltages with constant frequency and amplitude. This paper presents a control strategy based on disturbance observer reduced order and disturbance feedforward in the state space. Simulation results for balanced and unbalanced load shows high dynamic and stationary precision of the amplitude and frequency of the output voltage. Experimental results verify the proposed control method.