Robust and fine sinusoidal voltage control of self-sustained operation mode for photovoltaic generation system

This paper describes a control method for the self-sustained operation of a photovoltaic (PV) generation system to compensate the output voltage distortion compensation. In order to improve the output voltage distortion, the control circuit consists of sinusoidal tracking control based on the internal model principle. Moreover, the control system is configured by combining the sinusoidal tracking control and a notch type disturbance observer. Thus, this configuration of the control system produces lower output voltage distortion. In addition, the zero location of sensitivity function is relocated by appropriately modifying the feedback element of the disturbance observer. The simulation and experimental results confirm that the proposed disturbance observer effectively reduces the output voltage distortion and improves the disturbance suppression characteristics. The THD of the output voltage is improved by 3.15 % using the proposed zero re-allocated disturbance observer in the case of the resistance and rectifier.