Performance Evaluation of SVPWM Methods Using Effective Time Concept for Open-End Winding Induction Motor

This paper presents the performance evaluation of different space vector based Pulse width modulation (SVPWM) methods using effective time concept in conjunction with a 3 phase open-end winding induction motor (OEWIM). Typically to obtain supply at variable voltage and frequencies, all ac drives need to be fed with voltage source inverters (VSIs). These VSIs can be operated by providing the gating signals to the switches employed in the inverters. Various PWM schemes are available in order to provide these gating signals. Among all the PWM schemes, conventional SVPWM and carrier-based SVPWM are the most widely used PWM schemes. The usage of carrier-based SVPWM is increasing day by day due to their effortless digital realization along with desirable dc bus utilization. In this present work 2 two level three phase VSIs which are excited with two equal isolated dc voltages are employed to feed the desired drive. It facilities the employment of the switching devices and the dc buses at reduced voltage ratings in the system. This paper predominantly emphases on the implementation of three different carrier based SVPWM with use of effective time concept for an OEWIM drive. MATLAB/Simulink environment is selected to simulate different PWM schemes with different switching patterns for three phase OEWIM. Theoretical reflections are certified through the simulation results. The analysis is conducted for the selected modulation methods for linear modulation index values by means of Fast Fourier Transform (FFT) analysis on the dual inverter line voltage, OEWIM stator current waveforms and total harmonic distortion (THD) as statistics of quality.