For those electronic and electrical equipment (such as motor-operated appliances) which shows to be perceptual or capacitive, when they are in the normal work, the current waveform peak may lag or ahead of the voltage waveform peak and cause the decrease of the power factor of the product.
The common way used by this equipment is the corresponding capacitive or perceptual compensation. It aims at keeping the occurrence time of the compensation current waveform peak the same as the occurrence time of the voltage waveform peak. This kind of compensation way is almost used in the power factor compensation of the electric system, seldom used in the common electric and electrical equipment. Because the harmonic problem of the common electronic and electrical equipment is mainly the waveform distortion, but not only the problem of current waveform phase delay and phase advance. This kind of compensation way is not obvious.
For the common electric equipment, the increased component costs of this two kinds of passive power factor correction circuit is rather low, the volume is small and acceptable. The cost of the active power factor correction circuit is much higher than the passive costs, but the correction effect is better.
The active power factor correction circuit may be the last choice for those products which can not be suitable for other scheme. Of cause, some products will also use active power factor correction circuit to improve the product quality.