A potential transformer, also known as a voltage transformer, is a type of instrument transformer used in electrical power systems to step down high voltage electricity to a lower, measurable level for metering or control purposes.
In a 3-phase system, potential transformers are used to measure the voltage of each phase and transmit that information to protective relays and meters. This allows for efficient monitoring and control of the system.
A potential transformer works by using a primary winding to connect to the high voltage source and a secondary winding to connect to the measuring or control instruments. The ratio of turns between the primary and secondary windings determines the voltage reduction.
Using a potential transformer in a 3-phase system has several benefits, including accurate voltage measurement, isolation between high and low voltage circuits, and protection against voltage surges.
Potential transformers are commonly used in power generation, transmission, and distribution systems, as well as in industrial plants and commercial buildings for metering, monitoring, and protective purposes. They are also used in laboratory equipment and testing devices for precision voltage measurements.