VSC Control in Grid Connected PV Plant for Power Generation and Harmonics Mitigation During Partial Shading Irradiance Condition

The main objective of the work presented in this paper is the control and power quality enhancement of a photovoltaic system connected to a high voltage electrical grid. The system under study is composed of 400 kW PV field connected to a 66 kV grid via a DC/DC boost converter and a three-phase VSC (Voltage Source Converter). A smart control of the PV array power is realized using fuzzy logic technique. In addition, the grid current waveform improvement is ensured by suppressing the harmonic currents generated by the DC/AC PWM converter. To do this task, a passive LCL filter is designed to filter these harmonics to obtain a current THD (Total Harmonic Distortion) level of less than 5%. The effectiveness of the proposed filtering strategy is tested in terms of grid current depollution for different levels of power injection under partial shading irradiance condition. It verifies that the THD of the obtained grid current is according to IEEE Std 519-2014 harmonic limits.