Compared with ordinary motors, there is not much difference in appearance between frequency conversion motors and ordinary motors, but there is a big difference between the two in terms of function and utilization. The frequency conversion motor is powered by a frequency conversion power supply or a frequency converter. The speed of the motor can be changed. There are constant torque and constant power frequency conversion motors, while the ordinary motor is powered by the industrial frequency power supply, and its rated speed is relatively reliable.
The ordinary motor fan moves with the motor rotor at the same time, while the frequency conversion motor is driven by another independent fan to dissipate heat. This design can guarantee the heat dissipation requirement of the frequency conversion motor at low speed.
However, when ordinary motors are used by frequency conversion and run at low speeds, they may burn out due to overheating.
In addition, due to the high frequency magnetic field of the variable frequency motor, the insulation grade is higher than that of the ordinary motor. The slot insulation and electromagnetic wire of the variable frequency motor have special requirements to improve the ability to withstand high frequency attack waves.
The variable frequency motor can be adjusted at any speed within its speed range, and the motor will not be damaged. Ordinary motors can only run under the conditions of rated voltage and rated frequency.
The energy saving of variable frequency motors is mainly expressed in the application of fans and pumps.
The reason is that in order to ensure the reliability of the equipment operation, the manufacturer will choose a frequency conversion motor with a higher power when selecting a matching motor, leaving a certain margin for the equipment.
When ordinary motors cannot run under full load, in addition to reaching the power drive requirements, the excess torque increases the loss of active power and causes the waste of electrical energy.
The traditional speed adjustment method of fans, pumps and other equipment is to adjust the air supply and water supply by adjusting the inlet or outlet baffle and valve opening. The input power is large, and a large amount of energy is consumed in the process of blocking the baffle and valve. middle.
When using variable frequency speed regulation, if the flow requirement is reduced, the requirement can be satisfied by lowering the speed of the pump or fan. In this way, the consumption of electric energy is naturally reduced for the utilization of customers.