Active Damping Resonance Suppression and Optimization of Photovoltaic Cluster Grid Connected System

In order to effectively suppress the resonance problem of photovoltaic grid-connected system, an optimization method of active damping resonance suppression is proposed by combining active damping notch control method and active damper method. The resonance mechanism of photovoltaic grid-connected system is analyzed based on frequency domain analysis method. The notch filter is added into the active damping control method, and the active damping of the system is enhanced by using the notch characteristics. The virtual impedance is introduced in parallel with the active damper at the common bus to increase the system damping, which can suppress the system resonance effectively. Finally, the Matlab/Simulink simulation results show that the resonance suppression of photovoltaic grid-connected system can obviously improve the voltage waveform of the common bus, and make the total harmonic distortion rate of the common bus reach 1.07%, which is 0.55% lower than that of the single active damping notch control method, and the higher harmonic suppression effect is more obvious.