Research On Control Strategy Of Mine Electric Locomotive Switched Reluctance Motors Drive System

Mine electric locomotives are important tools for mining operations, features like large starting torque, overload capability, frequent starts and braking, safe and reliable are required because of bad transport environment. DC drive is adopted in mine electric locomotives previously for the good speed control performance, but it still has disadvantages such as complex structure, difficult to maintain and low efficiency. Though above shortcomings are not existed in AC motor, it failed to be widely used in electric drive system of mining electric locomotive for bad speed control performance until high performance AC drive speed control strategies like vector control are proposed with the development of power electronic technology currently, which make AC’s performance has met or exceeded the DC and achieve the transition from DC to AC. Variable frequency speed control systems based on AC asynchronous motor are widely used in mine electric locomotives for now. It is still less than ideal because of deficiencies like large starting current, low overload capability and power factor for the application condition of mine electric locomotives,though it has overcome the above shortcomings in DC. Due to the features of simple structure, low cost, small starting current, large starting torque, and reliability,Switched Reluctance Motor(SRM) is very suitable for application in the mine electric locomotive electric transmission system. Relative control methods about applying SRM in mine electric locomotive are studied.Firstly, following contents are introduced, the study situation and existing problem in mine electric locomotives, basic characteristics and development status of SRM, apply SRM into electric drive system in mining electric locomotive, basic structure and main contents of this paper.Secondly, basic structure, circuit equation, mathematical model and basic composition of SRM speed control system are introduced, basic principle of SRM traditional control methods and comparative analysis are explained. Aiming at the problem of large torque ripple and considering the working characteristics, adaptive fuzzy PI control based on direct torque control strategies are proposed.The design method of the proposed strategies is elaborated. Make speed control as outer control ring using adaptive fuzzy PI control, make torque control as inner control ring using direct torque control strategy. Theoretical analysis and design study about design method of inner and outer control ring.Build simulation model by MATLAB, simulation verification of control effect and comparison analysis with traditional methods are conducted, proving the efficiency and feasibility of proposed strategy.Use a certain type SRM as experimental subjects, design SRM control system experiment equipment with system controller TMS320F2812. Further experimental validation of the above theory through the equipment, modification and perfection on the algorithm of corresponding control algorithms are conducted, providing reference for for applying SRM into electric drive system in mine electric locomotive.