A Three-Phase Space Vector PWM Inverter for Induction Motor Drive with Leakage Current Reduction

Several industrial applications rely on induction motors to carry out processes essential for product manufacturing. Speed control of an induction motor commonly requires a pulse width modulated inverter capable of driving a system with long cables, suppression of common mode voltage, reduction of common mode current, and suppression of electromagnetic interference. This paper proposes a three-phase motor drive aimed to make constant the common mode voltage. The proposed system consists of two three-phase conventional full bridge inverters connected in parallel and having as an input two separate direct current sources. The proposed system is controlled by using the space vector pulse width modulation technique. By designing the adequate signal sequences of the switches for both converters, it is possible to keep constant the common model voltage and therefore reduce the associated common mode current making the system more reliable. The proposed system is validated through numerical simulations and by the implementation of an experimental prototype. Low common mode current values as low as 83mA are obtained in both simulations and experiments.