For the load should be how to choose a different frequency converter, if the load has a dedicated frequency converter, choose a dedicated frequency converter, if not, you can only choose a universal frequency converter.

So what are the three different load characteristics of the inverter? People often divide the load in practice into: constant torque load, constant power load and fan, pump load.

1.Constant torque load

Torque TL is not related to speed n, and TL remains basically constant at any speed. For example, conveyors, mixers and other friction loads, elevators, cranes and other potential loads, all belong to constant torque loads.

When the frequency converter drives the constant torque load, it needs to run at low speed and steady speed, so that the torque can be large enough and the overload capacity can be sufficient. Finally, the heat dissipation of the standard asynchronous motor should be considered to prevent the motor from heating up too high.

2.Constant power load

The torque of the paper machine, uncoiling machine and other specifications is inversely proportional to the speed n, which is the constant power load.

The constant power properties of the load change within a certain speed. When weak magnetic speed regulation, the maximum allowable output torque is inversely proportional to the speed, which is constant power speed regulation.

At very low speeds, due to mechanical strength limitations, the load torque TL has a maximum, so it will become a constant torque property.

The capacity of the motor and the capacity of the inverter is the smallest when the constant power and constant torque range of the motor is the same as the constant power and constant torque range of the load.

3.Fan, pump load

FGI frequency inverter manufacturer notes that fans, pumps and other equipment, with the reduction of speed, torque decreases according to the square of speed, and the power is proportional to the third square of speed. When saving electricity, it is necessary to use the inverter to adjust the air volume and flow rate by regulating the speed. Because the power required at high speed increases rapidly with the speed, the fan and pump load should not be allowed to run over the power frequency.