Sensitive Monitoring and Protection of Transformers by Gas Rate Monitoring

A new system for protection and diagnosis of oil filled high voltage devices based on monitoring of undissolved gases is introduced. The gases are measured with a capacitive sensor which can be installed on top of the Buchholz-Relay or instead of the Buchholz-Relay. The sensitivity of the sensor is better than 0.5 ml. Beside the gas amount the gas rate and the time of gas generation is registered. Additionally other operation and ambient parameters such as temperature, voltage, current and many more can be registered.