Power Factor defines the phase difference between current and voltage in an electrical circuit. In DC circuits, there is no phase difference between voltage and current that's why DC has no power factor. But in the case of AC, the power factor is very important. Reactive devices such as inductors, capacitors create a phase difference between voltage and current when AC supply is given.

When there is no phase difference between voltage and current or in other words when voltage and current both are in the same phase, the power factor will be unity.
When current lags behind the voltage, then the lagging power factor occurs.
When current leads behind the voltage, then the leading power factor occurs.

In an AC circuit, when the current leads behind the voltage and the system behave as capacitive nature, then the power factor will be leading.

Here you can see in the below figure, a pure capacitive load is connected to the AC supply. The current leads behind the voltage with the 90-degree angle. So it is an example of a leading power factor.

## Causes of Leading Power Factor

When a pure capacitive or a capacitive load is connected with AC supply then the leading power factor occurs.

When a pure capacitive load(which does not have any resistance) is connected with AC supply it does not take any active or real power. Only reactive power will flow in the circuit.

When a normal capacitive load(has some resistance) is connected with AC supply, it consuming a few active or real power and at the same time, reactive power also flowing in the circuit.

In a long-distance transmission line, two adjacent conductors create a capacitive effect that's why the leading power factor occurs. In this case, the shunt reactors(nothing but inductor) are used to improve the leading power factor in a long transmission line.

## Effects of Leading Power Factor

The main harmful effect of the leading power factor is, it creates a high voltage in the circuit which can affect the load as well as the power supply circuit.

Leading power factors can damage the power source devices such as generators, alternators, etc because generators, alternators cannot withstand the leading power factor.

Leading Power causes to increase the receiving end voltage than the sending end voltage in a transmission line.

Leading Power Factor Causes, Effects, Improvements Reviewed by ETechnoG on 1/18/2020 Rating: 5