Potentialtransformator

A Potentialtransformator, often abbreviated as PT, is a type of instrument transformer used in electrical power systems. Its primary function is to reduce high voltage levels to a lower, standardized voltage that can be safely measured by standard measuring instruments, relays, and control equipment. Essentially, it acts as a voltage reducer, mirroring the voltage on the primary side to a scaled-down voltage on the secondary side.

PTs operate on the principle of electromagnetic induction, similar to power transformers. They consist of a primary winding with a large number of turns and a secondary winding with fewer turns. When a high voltage is applied to the primary winding, it induces a proportional voltage in the secondary winding. The ratio of turns between the primary and secondary windings determines the voltage transformation ratio. This ratio is carefully designed to ensure the secondary voltage is a safe and manageable level, typically 100V or 110V, for connected equipment.

These transformers are crucial for the accurate monitoring and protection of high-voltage electrical networks. By stepping down the voltage, PTs enable the use of standard, less expensive, and more sensitive measuring devices that would be damaged or inaccurate if directly connected to high voltages. They are essential components in switchgear, substations, and power generation facilities for metering power consumption, voltage regulation, and fault detection. Safety is paramount, as PTs isolate the low-voltage measurement circuits from the high-voltage power system.