How to calculate the rated current of three-phase motor?

Rated current of three-phase motor = rated power ÷( 1.732× rated voltage× power factor× efficiency).

Calculation of rated current: I = p/( 1.732× u× cos φ× η)

(p = motor power: KW, u = power supply voltage: v, I = current: a, cos φ = power factor, η = efficiency)?

The rated current is the current flowing through the end of the winding calculated by dividing the rated capacity of the winding by the rated voltage of the winding and the corresponding coefficient (1 for single phase and √3 for three phases).

So the rated current of transformer is the rated current of each winding, which refers to the line current. However, if the windings of a single-phase transformer forming a three-phase group are connected in a triangle, the rated current of the windings is expressed by line current, with the numerator being √3 and the denominator being. For example, if the line current is 500A, the rated current of the winding is (500/√ 3) A. ..

Application scope of three-phase synchronous motor

Three-phase synchronous motor is widely used to drive high-power mechanical equipment that does not need speed regulation, such as rolling mills, turbocompressors, blowers, various pumps and frequency conversion units, because of its good characteristics of keeping the speed constant when the power supply voltage fluctuates or the load torque changes. Or used for driving various ball mills and reciprocating compressors with low power but low rotating speed;

It can also be used to drive the propeller of large ships. In recent years, due to the maturity and scale of SCR frequency conversion device technology, synchronous motor can also realize variable speed operation through frequency conversion. Therefore, under a certain control mode, the operation characteristics of three-phase synchronous motor are similar to those of separately excited DC motor, thus expanding its application range.