Voltage transformers (VTs or potential transformers) provide scaled-down, accurate representations of system voltages for metering, protection, and control. They isolate secondary circuits from high voltage while maintaining a precise ratio and phase relationship. This allows protective relays, meters, and automation systems to safely monitor and react to system conditions. In some contexts “power voltage transformers” can also refer to larger step-down units feeding auxiliaries, but usually it denotes instrument transformers dedicated to measurement and protection.