Design & Simulation of 3-Phase 3-Level Voltage Source Inverter for PV Synchronization to Grid

Abstract

The Solar Photovoltaic (SPV) systems which directly supply power to the grid are becoming more widely used. The photovoltaic (PV) field has given rise to a global industry capable of producing many gig watts (GW).The active and reactive power feed-in by grid-connected solar PV systems will result in voltage rise over its maximum limit in distribution systems. In This Project proposes different voltage control strategies to limit the voltage rise in low voltage distribution systems causedby grid connected solar PV systems. The voltage control strategies include four different active and reactive power control strategies. A power electronic converter which converts DC power from the PV array to AC power at required voltage and frequency levels is known as Inverter. Generally different Pulse Width Modulation (PWM) techniques have been implemented for grid connected 3-phase Voltage Source Inverter (VSI) system .On the basis of discussion of harmonic injection SPWM (HI-SPWM) and voltage space vector PWM (VSV-PWM), a novel SPWM technique (IF-SPWM), which is really simplest and well designed to obtain maximum inverter gain, minimum switching frequency and to avoid the disadvantages of HI-SPWM, is proposed. The IF-SPWM is based on instantaneously floating the equivalent neutral point of the output of a 3-phase inverter i.e. instantaneously injecting the same voltage waveform into the phase voltages. Modeling of photovoltaic systems includes modeling of SPV array, power electronics inverter/converter based on. In extension the proposed concept can be implemented for 3-phase 3-level VSI using SPWM for grid connected PV applications by using MATLAB/SIMULATION software