Study On Mine Hoist Doubly-fed Speed Control System Startup Mode

Scheme of a doubly-fed induction motor adjustable speed has many advantages and applied to the fans, pumps and wind power generation recently years. The features of all these applications are the flow load and non-frequently starting and stopping in the system. Therefore, the doubly-fed machine speed control system generally uses the rotor rheostat-type auxiliary starting or direct starting.This paper analyzes the principle and technological present status of the doubly-fed induction motor speed control system. In view of the mine hoist’s load and operation characteristics, the system structure and start-up mode of hoist’s doubly-fed speed regulation scheme are put forward. The system uses the scheme of doubly-fed speed adjustment in AC-DC-AC double PWM converter, and the hybrid startup operating mode both single and double feed. This scheme can reduce the power rating capacity of the converter and the cost of speed control system obviously. It also can drive the high voltage motor with the low voltage converter, and on the premise of without replace existing motor, the system can increase power rating of the mine hoist and has important meanings in the existing mine expansion. The scheme’s feasibility has been proved by the matlab simulation and experiments.