The supplier of the frequency converter braking unit reminds you that the frequency converter is a power control device that uses frequency conversion technology and microelectronics technology to control AC motors by changing the frequency of the motor's working power supply. The frequency converter is mainly composed of rectification (AC to DC), filtering, inversion (DC to AC), braking unit, driving unit, detection unit, microprocessor unit, etc.
1. Energy saving by adjusting the speed
In order to ensure the reliability of production equipment, industrial enterprises leave a certain margin between the driving capacity and the design load. Therefore, many motors may not operate at full load, resulting in excess torque and increased consumption of active power, leading to wastage of electrical energy. For this situation, the speed control function of the frequency converter can reduce the operating speed of the motor, thereby reducing the consumption of electrical energy while maintaining a constant voltage.
If the motor speed decreases from N1 to N2, its shaft power P will become:
P2/P1 = (N2/N1)3
It can be seen that reducing the motor speed can achieve a cubic level energy-saving effect.
2. Energy saving through dynamic adjustment of efficiency
The self configured measurement and control output function of the frequency converter continuously monitors load changes and quickly makes adjustments to adapt to load changes, thereby maintaining high efficiency of the motor output at all times.
3. Energy saving through V/F function
Under the condition of ensuring the output torque of the motor, the frequency converter can automatically adjust the V/F curve, reducing the output torque of the motor and lowering the input current, thus achieving the goal of energy conservation.
4. Energy saving through soft start function
As is well known, when a motor starts at full voltage, the current absorbed from the power grid according to the motor's starting torque requirements is about 7 times the rated current of the motor. However, if the starting current is large, it not only wastes electricity, but also causes significant fluctuations in the power grid voltage. The continuous fluctuations in the power grid will also increase line loss and transformer loss. Through the soft start function of the frequency converter, the starting current of the motor can gradually increase from 0 to the rated current of the motor, effectively alleviating the impact of the starting current on the power grid. This not only reduces the waste of high current electrical energy, but also reduces the significant impact of starting inertia on equipment, reducing equipment life loss.
5. Energy saving by improving power factor
Most three-phase asynchronous motors belong to inductive loads, and due to the large amount of reactive power absorbed by the motor during operation, the power factor is relatively low. After adopting a frequency converter, its characteristics become AC-DC-AC. Through the rectification and filtering process of the frequency converter, the impedance characteristics of the power grid become resistive, which improves the power factor and reduces reactive power losses.
Overall, frequency converters do have certain energy-saving effects in many situations, and even have extremely significant effects in certain situations. Therefore, as an excellent technological innovation, frequency converters are fundamentally worth promoting vigorously.