Research Of Battery Locomotive Drive System Based On Permanent Magnet Synchronous Motor

Mine-used battery locomotive is a kind of significant transportation equipment. It plays an important role in the daily production in coalmine because a large number of engineers and equipments are required to schedule by it. Now most of the battery locomotives still follow the traditional DC speed regulation system. Because of the mechanical commutator in DC motor coupled with the wretched conditions underground, the current locomotive has some disadvantages such as high failure rate and poor reliability. Meanwhile, the DC motor needs regular maintenance and brushes replacement. All of these affect the daily use of locomotives seriously. Permanent magnet synchronous motor (PMSM) has developed rapidly in recent years. A new generation of PMSM uses rare earth material so that it gets the characteristics of small size, high efficiency, simple structure and almost maintenance-free which is especially suitable for using underground.Aiming at the problems of the current battery locomotive, the article proposes a battery locomotive speed regulation system based on permanent magnet synchronous motor. It uses a high-performance algorithm of Vector Control, introduces the speed sensorless control technology and designs the hareware circuit and software flow diagram. This article researches two parts mainly:Firstly, according to the defaults of DC speed regulation system, the article designs a PMSM battery locomotive speed regulation system which uses Vector Control algorithm. It analyzes the basic structure and mathematical model of PMSM, and introduces the concept of coordinate transformation. At the same time, it explains how the Vector Control algorithm realizes the dual-loop control of speed and current for PMSM under the rotating coordinate system combined with the schematic diagram. According to the Vector Control of PMSM, the article analyzes the current control strategy of maximum torque per ampere (MTPA) and space vector pulse width modulation (SVPWM) algorithm. Then uses MATLAB to simulate performances of speed regulation system and compares the control effect to that of traditional V/F method.Secondly, according to the poor reliability problem of mechanical speed sensor, the article introduces the speed sensorless control technology into the locomotive regulation system and estimates the speed and rotor position angle of the motor with extended Kalman filter (EKF) algorithm. Then, derives the recursive process and corresponding formulas of PMSM speed and position angle estimation by linearizing and discretizing the state and measurement equations of PMSM. The feasibility and operating effect of EKF estimation algorithm are simulated in MATLAB and the article finishes the hardware and software design of battery locomotive speed regulation system with STM32F407as the core.The experiments results show that:by using speed sensorless Vector Control(SVC), the speed regulation system of battery locomotive can reduce system complexity while obtain the excellent dynamic performance and speed stabilized accuracy. It can satisfy the requirements of the actual work underground better.