నైరూప్య

Improved Z Source Inverter for Speed Control of an Induction Motor

D.Amudhavalli , L.Narendran

This paper presents an improved Z source inverter used to control the speed of an induction motor. The proposed Z source inverter (ZSI) can effectively reduce the voltage stress across the capacitors in the impedance network. This reduces the voltage range of the capacitors used, and also the cost of the proposed topology which is in turn used to control the speed of an induction motor which is used in many valuable industrial applications. The Z Source inverter is a combined inverter with an additional buck-boost feature and the proposed topology increases the efficiency of the circuit by reducing the voltage stress across the capacitors. This topology finds its applications in a number of renewable energy sources, where the input voltage is unreliable in nature and keeps varying from time to time. A speed sensor is connected to an induction motor to sense the actual speed, which is compared with a reference speed. A PI controller is designed which helps to run the motor to the reference speed. The simulation results indicate that the proposed topology is a promising technique that can be applied to improve the overall inverter efficiency.