Sliding Mode Control of a Mechanical Speed Sensorless dc Motor Drive Fed from a Current Controlled Chopper

This article deals with performance analysis and implementation of a four-quadrant chopper fed dc motor drive system. Control structure of the system is effected through a digital processor. The closed-loop control scheme of the drive utilizes the sliding mode controller (SMC) in its outer speed loop, while the inner loop is equipped with the Pulse Width Modulated (PWM) hysteresis current controller. An algorithmis evolved to eliminate the mechanical speed sensor. To simulate performance of the drive system, a mathematical model is developed. An experimental verification is carried out for the simulated performance.