Design and implementation of one kilowatt capacity single phase grid tie photovoltaic inverter

摘要

This Paper is aimed to present the design and implementation of a one kilowatt capacity single phase grid tie photovoltaic inverter. The proposed design and simulation process of this system is in PSIM simulation environment. The reason for choosing the software PSIM is that it provides the solar module facilities. For single phase grid tie inverter design some special types of consideration, like reference voltage creation to synchronise the inverter's output with grid, PWM (Pulse Width Modulation) signal creation by comparing the reference and triangular wave, is designed and simulated precisely. According to the PWM pulses, the solar module provided DC voltage is switched by using single phase bridge inverter circuit. After filtering and matching the inverter's AC output wave's amplitude and frequency with grid, this AC power is given to the grid by using isolation transformer. All of these fundamental criteria of an inverter are met in this inverter design. After analysing the simulated output a hardware prototype is also implemented. In hardware prototype, according to the reference signal, PIC18F4431 microcontroller is used for generating the PWM pulses. These PWM pulses act as the switching controlling pulses for IGBT (Insulated Gate Bipolar Transistor).