Do all substation power transformers have load tap changers?

• A. Yes
• B. No
• C. They may or may not
• D. Only large transformers

Answer: (C)

Voltage regulation in a substation often relies on devices that adjust transformer windings, so a transformer can keep the downstream voltage steady as load changes. However, not every transformer includes this feature. The presence of a load tap changer depends on design choices, size, and how voltage is regulated in the station. Some large, critical transformers have on-load or off-load tap changers to adjust voltage under load; others use fixed taps or rely on external regulators, capacitor banks, or other systems for regulation. Because of these variations, the correct understanding is that they may or may not have load tap changers.