Design and Implementation of a Single Phase Symmetrical Hybrid Sinusoidal Pulse Width Modulated Inverter for Improve Performance

摘要

The Inverter is widely used for various applications such as speed control of AC motors, photovoltaic interface, flexible AC transmission system (FACTS) and power conditioning devices. In the Square wave inverter output contains a large amount of lower order harmonics. To solve the problem a large bulky filter is required. In PWM techniques the output consists harmonics of high frequency. A small filter is required at the output to get sinusoidal output. In Hybrid PWM techniques two switches operated with high frequency PWM switching signals and two switches drives by low frequency signals. This causes unequal temperature rise at the switches which decreases the reliability of the system. This reduces the overall switching loss to nearly half compared to PWM technique. In Proposed symmetrical hybrid sine PWM (SHSPWM) technique each switch operated at high frequency and low frequency alternatively and at any time two switches operated at high frequency and two switches operated at low frequency. Therefore, the total switching loss becomes half and equally distributed among the all switches which improve the reliability of the system. In this paper starting from Square wave inverter SHSPWM inverter is simulated step by step and finally SHSPWM inverter is implemented in the laboratory. The performance of implemented SHPWM inverter is analyzed in terms of efficiency and total harmonics distortions (THD).