Working principle of high efficiency energy saving motor and frequency conversion energy saving motor
Working principle of frequency converter: the frequency converter we use mainly adopts the AC-DC-AC mode. Firstly, the power frequency AC power supply is converted into DC power supply through the rectifier, and then the DC power supply is converted into the AC power supply with controllable frequency and voltage to supply the motor. The circuit of frequency converter is generally composed of four parts: rectifier, intermediate DC link, inverter and control.
The rectifier part is three-phase bridge uncontrolled rectifier, the inverter part is IGBT three-phase bridge inverter, and the output is PWM waveform, and the intermediate DC link is filter, DC energy storage and buffer reactive power.
Working principle of high efficiency and energy saving motor:
New motor design, new technology and new materials are adopted to improve the output efficiency by reducing the loss of electromagnetic energy, thermal energy and mechanical energy.
1. It can be started directly and the asynchronous motor can be completely replaced;
2. The rare earth permanent magnet high-efficiency energy-saving motor itself can save more than 3% of electric energy than ordinary motor;
3. The power factor of motor is generally higher than 0.90, so it is unnecessary to add power factor compensator to improve the quality factor of power grid;
4. The motor current is small, which saves the transmission and distribution capacitance and prolongs the overall operation life of the system;
5. Adding driver can realize soft start, soft stop, stepless speed regulation, and further improve the power saving effect.
Difference between high efficiency energy saving motor and frequency conversion energy saving motor
1. High efficiency and energy-saving motor is to improve the operation efficiency of motor itself through manufacturing process
2. Frequency conversion energy saving refers to saving electricity by adjusting the motor speed. The energy conversion ratio is not improved, but reduced, because the loss of frequency converter is increased.
3. Frequency conversion speed regulation is mainly used in the occasion of load change, energy saving effect is very obvious. Its energy-saving principle is simply to change the frequency according to the need, and then change the output power.
4. For the situation of stable load, that is to say, when speed regulation is not required, the use of frequency converter will reduce the overall efficiency, but will cost electricity.
5. When the load changes greatly, both of them can save power, but the proportion of energy saving by frequency conversion is much larger. Compared with the common motor with the same power, the energy saving of high-efficiency and energy-saving motor can only be increased by a few percentage points.
6. The motor powered by frequency converter is called frequency conversion motor, which is different from ordinary motor. Frequency converter directly drives ordinary motor, which will damage the motor.
7. The energy-saving principles of the two are different, and they can be used at the same time. Both technologies need to be vigorously developed and popularized.