Practical Implementation of Embedded Controlled Reduced Switch Z-Source Inverter-Fed Induction Motor Drive

K Srinivasan,T Vijayakumar

doi:10.4236/cs.2016.79190

Abstract

A cost-effective component minimized embedded controlled Z-source inverter for induction motor drive is presented. The proposed topology combines the advantages of a traditional four-switch three-phase inverter with the advantages of the z impedance network (two inductors in series and two X connected capacitors). This new topology, besides the self-boost property, has low switch count and it can operate as a buck-boost inverter. As a result, the new embedded controlled reduced switch Z-source inverter system provides ride through capability during voltage sags, reduces line harmonics, improves power factor, reliability and extends output voltage range. Analysis, simulation and experiment result will be presented to demonstrate these new features.

Highlights

There are two existing inverter topologies used for adjustable speed drives: The conventional threephase Pulse Width Modulation (PWM) inverter and three-phase PWM inverter with a dc-dc boost converter [1]; the conventional PWM inverter topology imposes high stresses to the switching devices and motor and limits the motor’s constant power speed ratio
The advantages of RISC processor against complex instruction set computer (CISC) processor are RISC instructions are simpler and operate faster, A RISC processor takes a single cycle for each instruction, while CISC processor requires multiple clocks per instruction, which makes decoding a tough task, and the control unit in a CISC is always implemented by a micro-code, which is much slower than the hardware implemented in RISC
This work has demonstrated that the reduced switch three-phase Z-source inverter topology is a good alternative technology to the conventional three-phase inverter for more efficient, more reliable and less cost conversion systems

Summary

Introduction

There are two existing inverter topologies used for adjustable speed drives: The conventional threephase Pulse Width Modulation (PWM) inverter and three-phase PWM inverter with a dc-dc boost converter [1]; the conventional PWM inverter topology imposes high stresses to the switching devices and motor and limits the motor’s constant power speed ratio. How to cite this paper: Srinivasan, K. and Vijayakumar, T. The newly proposed Z-source inverter [3] has the unique feature that it can boost the output voltage by introducing shoot through operation mode, which is forbidden in traditional voltage source inverters With this unique feature, the Z-source inverter provides a cheaper, simpler, single-stage approach for applications of fuel cell. Six Switch Three Phase (SSTP) inverters have been widely utilized for variable speed induction motor (IM) drives [4]. These inverters have some drawbacks, which involve the losses of the six switches as well as the complexity of the control algorithms and interface circuits to generate six PWM logic signals. Advantages of the FSTP inverter over the conventional SSTP inverter are, reduced price due to reduction in number of switches, reduced switching losses, reduced number of interface circuits to supply logic signals for the switches, simpler control algorithms to generate logic signals, less chances of destroying the switches due to lesser interaction among switches and less real-time computational burden

Four-Switch Three-Phase Inverter Model

Z-Source Inverter-Fed Induction Motor Drive

Results and Discussion

Experimental Results

Conclusion