The actual power calculation formula of ac motor is as follows:
P = 1.732×UI×cos, where U is line voltage, I is line current, cos is the actual power factor.
Ac motor is used to realize the conversion of mechanical energy and ac electrical energy.Due to the great development of AC power system, AC motor has become the most commonly used motor.Compared with DC motor, ac motor has no commutator (see the commutator of DC motor), so it is simple in structure, convenient in manufacture and relatively firm. It is easy to make the motor with high speed, high voltage, large current and large capacity.Ac motor power ranges from a few watts to hundreds of thousands of kilowatts, or even millions of kilowatts.There are two common ways for AC motors to reduce current. The first is to reduce the load carried by the motor, and the current will naturally come down. However, at this time, the motor's power factor becomes worse, the reactive current component increases, and the proportion of line loss increases.Second is concatenated resistance, but at this time on the motor voltage is reduced, at the same time, the power of the motor output decline, if it is not like a fan with motor power decrease, load load will decline, but fixed load, the motor will be increased to meet the requirements of the load current, the final is on the motor current exceeds current and burned.
