Variable-frequency top cover drainage control system

The utility model provides a variable-frequency top cover drainage control system, which comprises a control system 1, the control system 1 is connected with a drainage system 2, a water level monitoring system 3, a man-machine interaction system 4 and an external power supply 5, and the control system 1 comprises a frequency converter 11, a PLC 12 and an in-situ control box 13. And a universal change-over switch is arranged in the in-situ control box 13 and is used for switching a manual/automatic/cut-off control mode. The PLC 12 and the frequency converter 11 control the drainage system 2 through a liquid level signal of the water level monitoring system 3, a control signal of the remote control system and a control mode signal of the in-situ control box 13. According to the variable-frequency top cover drainage control system and the control method thereof, wide applicability is achieved, variable-frequency operation, starting and stopping are conducted on the drainage pump according to the liquid level, t