PV supported unified power quality conditioner using space vector pulse width modulation

摘要

This paper presents a Photovoltaic (PV) supported Unified Power Quality Conditioner (UPQC) using Space Vector Pulse Width Modulation (SVPWM) for a three phase distribution system to improve the power quality as well as to reduce the burden on the three phase AC grid by supplying the power obtained from PV array. The PV array with a boost converter is connected to the DC link of the UPQC. It automatically senses the PV power and generates the shunt active filter reference currents using Instantaneous Symmetrical Components Theory (ISCT) on-line to supply the PV power to the grid. Thus it serves the dual purpose of correcting the power quality issues by working as UPQC and also transfers real power generated by PV to the grid. Over the years, hysteresis current controller has been the commonly used switching control technique due to its several advantages like simplicity, ease of implementation, good dynamic response and robustness. However, its major disadvantage would be that it gives widely varying switching frequency operation of Voltage Source Inverter (VSI). This results in uneven stresses on VSI switches. SVPWM is presented here to obtain constant switching frequency pulses for both the series and shunt active filters. Constant frequency pulses results in even stresses on the power switches of the VSI which increases reliability and lifetime. The SVPWM switching patterns can be easily generated with the availability of new generation DSPs. Simulation results on SVPWM switched PV supported UPQC is presented.