Fuzzy tuned real and reactive power regulation in GC-VSI for PV systems

Operating solar Photovoltaic (PV) under fluctuating irradiation and load with variable profiles is a challenging job. Besides, reactive power demand in grid-connected solar PV system makes it more challenging because of its limitations in reactive power capability. As per Indian electricity grid codes, reactive power compensation comes under ancillary services and it is mandatory nowadays. On PV source side, DC/DC boost converter, and on grid side, traditional three-phase Grid-Connected-Voltage Source Inverter (GC-VSI) are taken for research study. If real power delivered to the grid by GC-VSI is less than the capacity, the surplus capacity is used to provide reactive power. Normally, shunt capacitors or Flexible Alternating Current Transmission System (FACTS) devices are used at Point of Common Coupling (PCC) as compensation devices. In this work, the DC-link capacitor employed in front end of GC-VSI is utilised to serve reactive power control to the grid. An effective fuzzy-tuned direct current vector control is implemented to enrich reactive power control. Simulation studies carried with extensive MATLAB/Simulink platform illustrate the efficacy of suggested system and reveal that proposed approach is capable of effective reactive power support by the DC-link capacitor and extraction of maximum possible power from PV arrays.