MITIGATION OF T.H.D OF MICRO CONTROLLER BASED THREE PHASE VOLTAGE SOURCE INVERTER

Abstract

The use of power electronic devices plays a crucial role in control and transformation of electrical power.These devices are non-linear which takes enough space in all the regions of Power electronic converters. Inverter plays important role in industrial and domestic- applications for converting the direct current(DC) power into an alternating current(AC) power. Use of these controlled switches in inverters is gives a smooth and precise control for the transformation of electric power. But on the other hand, usage of these controlled switches results in the high level of Total Harmonic Distortion (THD) which has poor effects on the converter’s performance. This thesis aims at the mitigation of THD for three-phase voltage source inverter using low pass filter. This method is analyzed using fourier spectrum of the output phase voltages and the total harmonic distortion (THD). With addition to this, this thesis also discusses three phase inverter with 180 and 120 degrees conduction mode. RLC low pass filter is designed to reduce the lower order dominating harmonics and to lowers the total harmonic distortion (THD). The models for boost converter, gate driver circuit three phase inverter with 180 and 120 degrees conduction mode (with and without filter) have been simulated using proteus (simulator) and 8051 microcontroller is programmed using uKeil (programming software) to control the switching pattern of MOSFET’s.