Research On High Efficiency DC Driving Technology For Electric Locomotive Of Coal Mine

Battery electrical locomotive is a main transportation equipment in the well of colliery,which is drived by series-excitation DC electromotor mostly at the present time. In speed regulation series resistance is adopted abroad this many a day, but this quomodo has many drawbacks, such as energy costing of series resistance, speed regulation of many levels, striking fiercely when starting, and controller is operated with load, whose crunodes are often burned and needed to service at every turn. So, that a new DC drive of electrical locomotive used in coal mine is developed can not only enhance efficiency of excavating coal but also have great praxis significance for advancing technology of excavating coal and promoting developing of coal mine.In this paper Buck convertor is used in chopping speed regulation for electrical locomotive. And two convertors drive two electromotors of electrical locomotive separately controlled by PLC. The parallel-power-MOSFET method adopted in the main circuit reduces the noisiness and increases the power density. To avoid the high switching loss in the high-power switching supply, a new snubber blueprint with soft-switching is presented and the circuit structure of a passive and low loss snubber is designed, then the system mode and simulation analysis are also carried through. The ZCS(Zero Current Switching) and ZVS(Zero Voltage Switching) of main switches which reduces the switching loss and increases the conversion efficiency is realized. Commutator which functions without sparkle is designed, and bidirectional traction and applying the brake can transform smoothly controlled by PLC.According to the requirement of operation characteristic of electrical locomotive, on the basis of PWM control chip-SG2525 , both velocity and torque close loop control is realized. The optimizing control circuit is designed, and output voltage of converter is introduced to the adjustment. The circuit of pulse blockage and protective circuit of over-current and safeguard circuit which can give an alarm if abnormal functioning are all designed. A MOSFET drive circuit is designed with separate organ, tested and proved.The manufactured DC chopping drive has passed the locale test in the well of the coal mine, and its operation performance is all right and its efficiency is over 92%, which realizes high efficient drive and saves more energy, and has some economical and practical value. The works above make way for researching more deeply.