Transformer Protection Devices | Types and Their Functions to Prevent Electrical Faults

Transformer protection devices are used to protect transformers from electrical faults, such as overcurrents, short circuits, and ground faults. Here are some of the most common transformer protection devices:

1. Buchholz Relay: A Buchholz Relay is a type of oil and gas actuated protection device that is placed in the piping between the transformer tank and the conservator tank. It detects the presence of gas generated by a fault in the transformer's oil or windings and trips the transformer before damage can occur.

2. Differential Protection Relay: Differential protection is a widely used protection scheme for transformers. This type of relay operates on the principle of comparing the currents entering and leaving the transformer. If there is any difference between the two currents, it indicates that there is a fault somewhere in the transformer, and the relay will trip the transformer.

3. Overcurrent Protection Relay: Overcurrent protection relays are used to protect transformers from overcurrents that can occur due to short circuits, overloads, or ground faults. These relays measure the current flowing through the transformer and trip the circuit breaker if the current exceeds a certain threshold.

4. Ground Fault Protection Relay: Ground fault protection relays are used to detect and trip the transformer if there is a ground fault. They measure the current flowing to the ground and trip the transformer if the current exceeds a certain threshold.

5. Temperature Monitoring Devices: Temperature monitoring devices are used to monitor the temperature of the transformer and detect any overheating that can occur due to a fault. These devices can include thermocouples, resistance temperature detectors (RTDs), and infrared sensors.