Vector Control Based Delta Modulation Inverter of Induction Motor Drives

This paper presents a new technique using delta modulation (DM) for static PWM inverter application. This technique was found useful for variable speed PWM inverter-fed a 3-phase induction motor drives. Current control technique is used as a current regulator for pulse width modulated (CR- PWM) IGBT inverters. The control strategy is based on the discrete delta modulation principle. The theory of field oriented control (FOC) was used for modeling the transient response of induction motor drives. Therefore, this theory is adopted and a model for the induction motor is achieved using the SIMULINK/ MATLAB software. Simulation results for speed, current and torque are obtained at various load conditions. Steady state and dynamic performance for the induction motor are also obtained in the case of a sudden change in speed or torque. The simulation results gave good results for the waveforms of stator current at steady state. These waveforms were approximately free of ripple with minimum harmonics.