Control of Two 3-Phase BLDC Motor Drives Using a Five-Leg Inverter

This paper proposes a control scheme for independent control of two three-phase BLDC motor drives using a five-leg inverter (FLI). In a conventional drive system, two BLDC motors would require a six-leg inverter or two three leg inverters. The proposed control scheme using FLI topology results in reduction in the number of switching devices leading to reduction in overall size, weight, and cost. Control of the common leg connected to both the motors becomes crucial while implementing two-phase conduction mode of operation in BLDC motors. The control scheme developed considers the current requirements of the motors for different operating conditions to achieve independent control over the motors. The proposed control scheme is validated by performing simulation using MATLAB-Simulink software for independent speed control of individual motors under different operating conditions like no-load, full load, same speed, and different speeds of the two motors.