Shunt Reactor for Changing Power Factor from Leading to Lagging:

A shunt reactor is a device that is used to compensate for leading power factor in an electrical system. It is connected in parallel with the load and is primarily used to absorb reactive power. When the power factor of a system is leading, it means that the load is producing more reactive power than required. By connecting a shunt reactor, the excess reactive power can be absorbed, thereby changing the power factor from leading to lagging.

Shunt reactors are typically used in high-voltage transmission systems where long transmission lines are present. These transmission lines can exhibit capacitive reactance due to the length and the capacitance between the conductors. This capacitive reactance leads to a leading power factor. By connecting a shunt reactor in parallel with the transmission line, the capacitive reactance can be compensated, and the power factor can be adjusted.

The shunt reactor operates by consuming reactive power and producing a lagging power factor. It consists of a coil wound on a magnetic core, which is connected in parallel with the load. When the load produces excess reactive power, the shunt reactor absorbs it, reducing the overall power factor. The absorbed reactive power is converted into magnetizing current, which flows through the reactor.

The shunt reactor is designed to have a specific reactance value, which is chosen based on the required power factor correction. By adjusting the reactance value of the shunt reactor, the power factor can be controlled and adjusted to the desired value.

In summary, a shunt reactor is used for changing the power factor from leading to lagging. It is connected in parallel with the load and absorbs excess reactive power, thereby reducing the power factor. Shunt reactors are primarily used in high-voltage transmission systems to compensate for the capacitive reactance of long transmission lines.