USING THE MODIFIED REFERENCE SIGNAL TO EXTEND THE RANGE OF LINEAR MODULATION IN ELECTRIC DRIVE

Abstract

This paper presents the results of research and application of modified pulse width modulation method to extend the range of linear control in electric drive. By using modified reference signals, the linear control range of modulation index m is extended from 0.785 to 0.907, or able to control the motor at over rated speed range with amplitude modulation index m_a up to 1.125. The motor is controlled by indirect field-oriented control with rotor flux orientation method, using five-level cascaded H-bridge inverter. The results are verified by simulation using PSIM software shows the motor able to operates in the overmodulation region with better electric torque response.