R&D Of Power Supply Control Device For Diesel Locomotive Auxiliary System

AC drive is considered as an important development direction of Auxiliary system for diesel locomotive. Based on the development of the auxiliary system for foreign diesel locomotive, the dissertation focuses on the study of both advantage and disadvantage of the auxiliary system approach for 8CJ, NJ1, NJ2 locomotives, and points out a new research approach: using three-phase PWM rectifier.The dissertation sets up the mathematical model of voltage source three-phase PWM rectifier, and designs the controller which consists of voltage and current double closed loop control. The controller inducts current state feedback and carries through forward compensation with AC main voltage to dismiss current coupling in dq coordinate. The dismissed-coupling current becomes separate dq current component; it not only can accurately track the current without static error in steady state, but also has quickly dynamic respond performance.Introduces the main power circuit and the composed of control device. The control device includes main control board, power supply board, in-out board and mother board. And the main control board is the core of the whole control, mainly composed of central processing unit, analog signal processing unit, logic protecting unit and communicating unit.Adopting voltage-oriented (VOC) PWM commute control strategy, the dissertation puts forward an easy digital arithmetic to realize VOC, so calculation is reduced greatly. The voltage and current of the three-phase PWM rectifier have better respond performance, the current aberrances is smaller and the voltage is steady under this control strategy.Based on the mathematic model of synchronous motor, the dissertation analyzes the control strategy in inverting state and rectifying state. The variable frequency starting is the first process of the system, it include rotor standstill position detection, v/f mode invert and flux weakening control, their control principle and control strategy are given. Rectifying is the second process of the system, based on analyzing the mathematic mode of synchronous motor and the control principle of voltage source rectifier (VSR) , the dissertation puts forward a new control strategy.The experimental results show that the PWM rectifier has good respond performance and can implement PWM commute with unity power factor, and met with the control target.