Three-phase asynchronous electromotor runs power factor and loss

When three-phase asynchronous electromotor moves, the power that consumes includes have rendered great service power and without result power two heft. Power of have rendered great service is to be used at electromotor to produce mechanical torsion and the power that drive load needs, its electric current follows laden addition and increase, and without result power, it is to be used at the electric field of electromotor interior and magnetic field to change as the iteration of power source frequency, in the power that when undertaking energy is exchanged ceaselessly between load and power source, consumes. Below the circumstance that changes in load without result electric current, its change is very little, be in phasic on, voltaic change always is lag at voltage 90 ° , be pure inductance property so. In moving actually, the total electric current of electromotor of power source supply is electric current of have rendered great service and the vector that do not have result electric current are mixed, when electromotor is in full load to move, electric current of have rendered great service is more than without result electric current, the power factor of total electric current is higher, and when load drops, electric current of have rendered great service is reduced, without result electric current basic and changeless, so power factor is reduced.

Such OK thinking: When the output power of electromotor is certain, power factor is lower, jump over without result power with respect to what mean its place to need big, the loss that causes consequently is bigger also. Carry out a proof, without the electric energy loss that result power place produces, basically be to produce what be defeated by distribution circuitry to go up, further to those distance power source, circuit resistor R is bigger, electromotor runs the terminal unit with power small factor, what cause without work loss more outstanding.