SOLUTION

A transformer can have regulation closer to zero on the leading power factor.

Voltage Regulation of Transformer

Voltage regulation is defined as the ratio of the difference between no-load voltage and full load voltage to no-load voltage. Voltage regulation depends on the nature of the load.

For lagging and unity power factor V₂ > E₂.
where,
V₂ = Secondary terminal voltage on a given load.
E₂ = Secondary terminal voltage on no load.

• As the load increase, it tends to become capacitive and V₂ start increasing.
• In case the load has a leading power factor, the voltage drop is less than what it is in the case of the unity power factor load. If the effect of voltage drop due to resistance is exactly balanced by the voltage drop due to reactance, it is possible to have V₂ = E₂, i.e., the voltage on load remains the same as the voltage on no-load, and regulation becomes zero.
• In leading, the power factor condition load is just able to supply the reactive power for the active power flow.

In a transformer, minimum voltage regulation occurs when the power factor of the load is leading.

The voltage regulation of the transformer is zero at a leading power factor load such as a capacitive load.