The supplier of the frequency converter braking unit reminds you that the frequency conversion speed regulation of electric motors has gradually become a symbol of the times. Synchronous motor operation speed regulation is the frequency conversion speed regulation control of AC electric motors driving square torque load machinery such as fans and pumps in the production process. Variable frequency speed control can achieve the best process effect and significant energy-saving and consumption reducing effects.
1. Energy saving effect
The mechanical equipment driven by traditional brushless excitation synchronous motors, such as fans, pumps, and compressors, operates at a constant power output at the power frequency. When the process adjusts its flow rate and pressure, serious energy waste will occur because the flow rate is proportional to the speed of the load, and the required power is proportional to the third power of the speed. Therefore, if the required flow rate is 80% of the rated flow rate, in this practical situation, using modern variable frequency speed regulation automatic control can save more than 45% of electricity compared to traditional regulation methods.
2. Variable frequency operation process control
Variable frequency speed regulation operation is a single machine control system. The process of variable frequency speed regulation operation is basically the same as that of variable frequency speed regulation soft start, but there are differences. The difference is that after the main control room issues the preparatory command for variable frequency speed regulation operation control of the synchronous motor, the turning drive motor of the synchronous motor drives it to rotate. When the rotational speed of the synchronous motor reaches 1% of the rated speed, the synchronous motor follows the designed program to instruct the control system to activate the excitation control. After the excitation control is activated, the main control room issues a "permission to activate" signal, which indicates the closing of the soft start high-voltage switch signal for variable frequency speed regulation operation. At the same time, the main control room immediately closes the high-voltage switch of the main control circuit of the soft start control system for variable frequency speed regulation operation of the synchronous motor based on signal instructions, so that the synchronous motor is in the soft start operation state of variable frequency speed regulation control.
In the process of frequency conversion and frequency modulation soft start control of synchronous motors, the polarity of the rotor magnetic poles of the synchronous motor remains unchanged, and it accelerates and rotates with the frequency of frequency conversion speed regulation, gradually increasing the voltage and frequency conversion speed, so that the synchronous motor runs at the rated speed, and completes the frequency conversion speed regulation soft start control.
During the operation of synchronous motors with variable frequency speed regulation, the variable frequency speed regulation control system, micro industrial control electronic computer control system, and vector operation control achieve stable and precise speed control according to the actual load changes.
Before stopping the synchronous motor during variable frequency speed regulation operation, the variable frequency speed regulation operating device must automatically reduce the output current to zero and block all triggering pulses of the variable frequency speed regulation operating device before giving the "allow stop" signal display. The overall control shall immediately disconnect the main control circuit high-voltage switch power supply of the variable frequency speed regulation operation control device based on the display signal instructions, and end the variable frequency speed regulation operation control process.