In AC circuits, the cosine of the phase difference between the voltage and current (phi) is called power factor, with symbolic power factor means that, numerically, the power factor is the ratio of active power and apparent power, cosΦ = P / S

The power factor of the size and nature of the load circuit, such as incandescent bulbs, power factor of 1 of the resistive load resistance furnace, generally having inductive or capacitive load circuit power factor less than 1. The power factor is an important technical data of the power system. The power factor is a measure of the level of a coefficient of efficiency of electrical equipment. The power factor is low, the circuit is used to convert an alternating magnetic field of reactive power, thereby reducing the utilization of the device, increasing the loss of line-powered. Therefore, the electricity sector is the power factor of the power units have a certain standard requirements.

    (1) basic: take the equipment for example. For example: the device power is 100 units, that is, 100 units of power delivered to the device. However, the inherent reactive power loss due to most of the electrical system, can only use the power of the 70 units. Unfortunately, although only 70 units, 100 units are required to pay fees. (Our day-to-day user METER active power, without measurement of reactive power, did not say 70 units and 100 units are required to pay the cost of the claim, the active power of 70 units, you pay consumption is 70 units) In this example, the power factor is 0.7 (most of the equipment the power factor of less than 0.9 will be fine), this reactive power loss is mainly present in electrical equipment (such as blower, pumps , compressors, etc.), also known as inductive load. Power factor is the motor efficiency standards for measurement.

    (2) Fundamental Analysis: each motor system are two major power consumption are real useful work (called kW) and electric resistance exercise in futility. The power factor is the ratio between the useful work and the total power. The higher the power factor, the higher will be the ratio between the useful work and total power, the system runs more efficiently.

    (3) Analysis: In the inductive load circuit, the current waveform peak occurs after the voltage waveform peak. Two waveforms separated peak power factor available. The lower the power factor, two the waveform peaks separated bigger. Paul two peaks can re-close together, thereby enhancing the efficiency of the system.