Traction speed regulation system and traction speed regulation control method for permanent magnet motor of coal mining machine

The invention relates to a coal mining machine permanent magnet motor traction speed regulation system and a traction speed regulation control method, and the system comprises a first frequency converter, a first contactor and a first permanent magnet motor which are connected in sequence, and a second frequency converter, a second contactor and a second permanent magnet motor which are connected in sequence, the three-phase power supply, the main contactor, the first frequency converter and the second frequency converter are sequentially connected, the first permanent magnet motor and the second permanent magnet motor are provided with a first sampling module and a second sampling module respectively, sensing signal output ends of the first sampling module and the second sampling module are connected into the main control unit, and the main contactor, the first contactor and the second contactor are controlled by the main control unit to be connected and disconnected. The first frequency converter and the se