Rotary vane vacuum pump energy saving control device including rotary vane vacuum pumps and connected to the drive of the asynchronous motor, rotary vane vacuum pump need vacuum sealed container, and vacuum gauge pressure regulating device, control unit and communication. Vacuum gauge pick up the air pressure sensor is located in the sealed container, the electrical signal output end of the vacuum gauge connected to control device, control device for the control of termination and grid connection of ac voltage regulation device, ac voltage regulation device outputs the asynchronous motor.
The vacuum gauge receives the gas pressure signal in the sealed container sent by the pressure sensor, and the warp sends the amplifier into the control device. Control units are stored according to gas pressure signal to adjust the voltage application, will receive the gas pressure signals compared with the set value, when they were pumping the gas pressure is lower than the setting of the container, step-down instruction for ac voltage regulation device. According to the instructions of the control device, the ac voltage regulating device provides a lower voltage to the asynchronous motor when the gas pressure is reduced, thus reducing the energy consumption. The vacuum gauge is equipped with a gas pressure display table to show the current gas pressure in the sealed container.
Ac voltage regulation device can be change the way of asynchronous motor wiring device, control device in the gas pressure is less than the set value, a step-down instruction, connection of ac voltage regulating device receives the step-down order will to star connection to reduce the motor stator phase voltage, step-down instructions when the control device, the triangle connection mode of asynchronous motor. The method is simple in structure and low in price, but the power supply voltage is only two files and cannot be adjusted accurately.
Ac voltage regulation device can also be a three-phase thyristor phase shift exchange regulating device, control device according to gas pressure gauge of step-down instruction, when receives the control device of the step-down instruction, stepless adjustment for the voltage of the motor down, can achieve maximum efficiency control. However, the control is more complicated and the cost is higher, and the three-phase thyristor phase-shifting alternating voltage will increase the harmonic current of the electric network and the harmonic loss of the motor, and the energy saving effect will be reduced.
Ac voltage regulation device can also be a three-phase sinusoidal pulse width modulation (SPWM) ac voltage regulation device, control device according to gas pressure of decompression instruction, when receives the control device of the step-down instruction, stepless adjustment for the voltage of the motor down, achieve maximum efficiency control. This kind of pressure regulation is ideal, but the control is complex, the cost is expensive.
The ac voltage regulator is connected to the power grid by the load protection device. The overload protection device is an asynchronous motor to protect the circuit breaker or the thermal relay.