DC Motor Velocity Adaptive Control through Buck-Boost AC/DC Converter with Power Factor Correction

This paper deals with the problem of velocity control of DC motors taking account the dynamics of the involved power converter. The latter is an AC/DC Buck Boost type. First, a 6th order model is developed for the global system, constituted of the motor and the converter. Based on this model, a regulator is then designed, using the backstepping technique, to achieve speed regulation and unitary power factor operation. The proposed regulator involves three loops: (i) an inner current control loop enforcing the converter input current to be in phase with the electric network voltage (unitary power factor), (ii) an outer speed control loop that regulates the machine velocity, (iii) a parameter adaptation loop that compensates the load torque uncertainty. The resulting multi-loop adaptive nonlinear regulator is formally proved to meet its objectives. This is further checked by simulation.