Improved speed control of dual induction motor drive powered by a single five-leg VSI

This paper proposes an improved speed control method for a dual-induction motor drive powered by a single five-leg voltage source inverter. Generally, dual- and multi-motor drive systems are widely used in electric vehicles, traction systems and in several industrial applications. The proposed solution utilizes field-oriented control scheme as basis. The space vector pulse-width modulation technique was used to generate the output voltages. The main purpose of the proposed solution is to utilize the additional degree of freedom provided by a dual-motor drive system. The improved speed control system consists of two blocks: an additional computation block and a rotor flux position control block. The proposed control technique allows for effective control of the rotor speed of two independent three-phase IMs, regardless of load conditions. Under limited conditions, when the rotor speeds of both motors are the same, the proposed rotor flux position control allows to achieve higher modulation indexes and decrease energy losses as well. Simulation studies were carried out in PLECS software, the obtained results proved the effectiveness of the proposed control scheme. To identify the feasibility and effectiveness of the proposed control system, an experimental validation was conducted. Simulation and experimental results are shown and discussed in this paper.