What Is The Function Of Buchholz Relay In Power Transformer

Power transformers are a crucial part of the electrical power generation and distribution system. They are designed to convert high voltage, low current power to low voltage, high current power, and vice versa. However, the safe and efficient operation of power transformers is essential to ensure the continuity of power supply. To achieve this, various protective devices are employed, including the Buchholz relay.

So what is a Buchholz relay, and what is its function in power transformers? A Buchholz relay is a protective device that primarily detects and alerts operators of any internal problems within the transformer tank. It is named after its inventor, Max Buchholz, a German electrical engineer who developed it in 1921.

The Buchholz relay is installed between the transformer tank and its oil conservator. It operates on the principle of gas detection. When transformer oil decomposes due to natural aging or as a result of a fault, gas is produced that accumulates in the transformer tank. If the volume of gas reaches a critical value, it displaces the oil and creates a space in which the air and gas mixture can form. This creates a pressure difference between the transformer tank and the oil conservator, which triggers the Buchholz relay to trip.

The Buchholz relay consists of a gas collection chamber, a float switch, and a contact system. When the gas concentration in the transformer tank exceeds the normal level, the float switch moves upwards, closing the contact system and tripping the alarm, which alerts the operator.

The primary function of the Buchholz relay is to detect faults early before the transformer is severely damaged. It helps to reduce the extent of the damage, keep repair costs down, and avoid blackouts. Some faults that the Buchholz relay can detect include electrical faults, insulation faults, and loose connections in the transformer.

In summary, a Buchholz relay is a crucial protective device in power transformers. Its primary function is to detect internal problems within the transformer tank and alert operators promptly to take necessary action. The use of a Buchholz relay can help prevent catastrophic failures, minimize damage and reduce the cost of repairs, and ensure the continuity of power supply.