CT/PT Transformer

A CT (Current Transformer) and PT (Potential Transformer) are both types of instrument transformers used in electrical power systems.

A current transformer, or CT, is designed to measure high currents flowing through power conductors. It consists of a primary winding and a secondary winding. The primary winding is connected in series with the conductor carrying the high current, while the secondary winding is connected to a measuring or protection device. The primary winding has a lower number of turns compared to the secondary winding, resulting in a reduced current being detected and measured by the secondary winding. CTs are used for accurate measurement, metering, and protection of high currents in power systems.

A potential transformer, or PT, is used to measure high voltages in power systems. Similar to a CT, it also has a primary winding and a secondary winding. The primary winding of a PT is connected in parallel across the high voltage line, and the secondary winding is connected to the measuring device. The primary winding is designed with a high voltage rating, while the secondary winding provides a lower voltage proportional to the high voltage being measured. PTs are commonly used for voltage measurement, metering, and protective relay applications in power systems. They allow for accurate and safe measurement of high voltages.

Both CTs and PTs are essential components of power system measurement and instrumentation. They ensure the safe and reliable monitoring of electrical currents and voltages, enabling effective control and protection of power systems.