The relationship between the current, voltage, power, efficiency, power factor and other parameters of motor products will always have a parameter change that affects the change of other parameters.

High efficiency motor, especially under the dual carbon target, the improvement of motor efficiency has become a very hot topic. Motor manufacturers and motor users are very concerned about the efficiency compliance of the motor.

In the process of updating the 18613 standard version of GB, the motor will always be replaced due to the improvement of efficiency. During motor replacement, some users questioned the changes of power factor and rated current of high-efficiency motor. That is to say, after replacing the high efficiency motor, it will be found that sometimes the power factor of the motor decreases, and the rated current of some motors increases compared with the original low efficiency motor. Therefore, it is very doubtful whether the efficiency of the motor is improved, and whether the motor they buy is a high efficiency motor? In response to this problem, we also have related Twitter, this time through the corresponding formula for qualitative analysis.

1、Why is the power factor of high efficiency motor low?

Through the output power, the efficiency, power factor and current of the motor are interrelated.

When the output power is determined, the line voltage is constant. Under normal circumstances, the current variation range is very small, so the efficiency and power factor usually increase and decrease each other, which is finally reflected in the high efficiency of high-efficiency motors, but the power factor is often relatively low.

2、Why is the current of high efficiency motor high?

We analyze this problem from the composition of the current. The current of the motor consists of active current and reactive current, wherein the reactive current includes excitation current and leakage reactance current. In order to pursue high efficiency, the power factor of high efficiency motors is generally low, and the excitation current is large, that is, the reactive current increases, and the corresponding total current is naturally large.