Quick calculation of power of three-phase asynchronous motor

The use of three-phase asynchronous motor should be familiar to everyone, we will use its power speed calculation method when we use it, which will improve our work efficiency, but 

some users are not very clear, we as a professional manufacturer to tell you now, take a look.

The motor is an ordinary three-phase asynchronous motor, Y-type connection. Rated voltage -380V, rated power 7.5KW, rated current 15.2A. Through experience, the total power of the 

three-phase motor is equal to 3 times the power of each phase, that is, p=3*u*i, where: p is the total power of the three-phase motor, unit watt u is the phase voltage, unit volt i is the 

phase current, unit amperage note: It is also known that the line voltage is equal to 1.732 times the phase voltage, and the line current is equal to the phase current, that is, p=3* (U/1.732)

 *I where: p is the total power of the three-phase motor, the unit watt U is the line voltage, that is, 380 volts I is the line current, that is, the measured current of the clamp ammeter, the 

unit ampere: The formula p=1.732*U*I solution to the problem in summary, P=1.732*U*I*cosφ/1000, among which: P is the active power of the three-phase motor, the unit kilowatt U is 

the line voltage, that is, 380 volts I is the line current, that is, the measured current of the clamp ammeter, the unit ampere cosφ is the power factor, for the motor is usually taken 0.8<BR>,

 so: P=0.52*I≈0.5*I (KW), the formula is proved.

Related knowledge:

Three-phase four-wire system

Three-phase four-wire power supply mode, that is, the TN-C mode stipulated by the International Electrotechnical Commission (IEC), is to use the working neutral line as a zero protection 

line, which can be called the protective neutral line, which can be expressed by NPE. So there are three phase lines and one neutral line. The three-phase five-wire power supply mode, 

that is, the TN-S mode stipulated by the International Electrotechnical Commission (IEC), is a power supply system that strictly separates the working neutral line N and the special 

protection line PE. Therefore, three phase lines, one working neutral line, and one protection neutral line. The single-phase three-wire system is part of the three-phase five-wire system, 

that is, the TN-S system according to the International Electrotechnical Commission (IEC) standard and the national standard, and the N and PE lines appear in the distribution. Therefore 

phase line, neutral line, ground line. The three-phase three-wire system is generally used for power transmission and factory power supply, which is not the way prescribed by the 

International Electrotechnical Commission (IEC).

V connection

The three-phase three-wire triangular connection is three groups of coil head and tail connection, suitable for 4.5KW motor The three-phase four-wire Y-shaped connection, also known 

as the star connection, is three groups of coil three tail connection, forming a Y shape, suitable for 4.5KW or more motor.

Line voltage, line current

Phase voltage refers to the voltage of a phase load to the ground, in the three-phase four-wire system, that is, the voltage between the phase line and the neutral line. Line voltage is the 

voltage of the phase to the phase, in the three-phase four-wire system, that is, the voltage between the phase lines. Therefore, in the Y-shaped connection using the three-phase four-wire

 system, the line voltage is equal to 1.732 times the phase voltage, and the line current is equal to