What's the difference between universal inverter and fan pump converter?
Constant power load:The torque required by machine spindles and rolling mills, paper machines, and plastic film production lines is generally inversely proportional to the rotational speed, which is called constant power load. The constant power nature of the load should be in terms of a range of speed variations. When the speed is very low, the mechanical strength limit, TL can not be infinitely increased, at low speed into a constant torque nature. The constant power area and the constant torque area of the load have a great influence on the choice of transmission scheme. When the motor is in constant flux speed regulation, the maximum allowable output torque is constant, which belongs to constant torque speed regulation. While in the speed regulation of magnetic flux weakening, the maximum allowable output torque is inversely proportional to the speed, which belongs to constant power speed regulation. If the constant torque of the motor and the range of constant power speed are consistent with the constant torque of the load and the range of constant power, the capacity of the motor and the capacity of the converter are all the smallest, which is called "matching".
In practice, the production machinery is often divided into three types: constant torque load, constant power load and fan, pump load.Constant torque load:The load torque TL is independent of the speed n, and the TL remains constant or almost constant at any speed. For example, conveyor belts, mixers, extruders and other friction loads, as well as cranes, hoists and other potential loads are constant torque load.When the inverter drives the load with constant torque, the torque at low speed is large enough and has enough overload capacity. If it is necessary to operate at a low speed, the cooling capacity of the standard asynchronous motor should be taken into consideration, so as to avoid the excessive temperature rise of the motor.
Fan and pump load:In a variety of fans, pumps, oil pumps, with the rotation of the impeller, the air or liquid within a certain speed range of resistance is roughly proportional to the speed of the 2 side of the n. As the speed decreases, the torque decreases by 2 times the speed. The power required for this kind of load is proportional to the 3 power of the velocity. When the required air volume and flow rate are reduced, the frequency and speed of air flow can be regulated by the frequency converter, so the energy can be saved substantially. Because the power required at high speed increases with the speed, and is proportional to the speed of the three side, so the fan and pump load should not be used in the ultra power frequency operation
