An Improved Control Strategy of PMSM Drive System with Integrated Bidirectional DC/DC

Abstract

With the development of power electronic technology, adding bidirectional DC/DC to the DC side of the motor controller has become an effective way to broaden the speed of motors. However, the motor drive system integrated with bidirectional DC/DC increases the switching loss and current harmonics of the inverter. Therefore, in this paper, a method based on fixed space vector pulse width modulation (SVPWM) modulation index and voltage instruction compensation are proposed, In this method, by considering the back electromotive force of the motor and the security margin of the weak magnetic region, the output voltage command amplitude of the current loop and the limit value of the inverter output is judged, and the optimal inverter input voltage is obtained, which effectively reduces the switching loss of the inverter, broadens the high efficient area of motor operation, and improves the efficiency of the controller. At the same time, the standardized benchmark composed of motor parameters is used to per-nit the permanent magnet synchronous motor (PMSM) mathematical model, which is helpful for the derivation of the formula and dramatically simplifies the calculation amount of the microcontroller. Moreover, the simulation and experimental results prove the effectiveness and feasibility of the algorithm.