工业变压器漏电检测

工业变压器应用广泛，体积可能非常大。在制造或维修变压器时，必须检查其是否完全防漏。这一点至关重要，因为变压器中充满了矿物油，矿物油用于冷却设备、提供电气绝缘和防止氧化。

如果在注油过程中发现泄漏，则必须先排出所有油，然后才能解决问题。这将导致大量的时间和成本损失。

Current method: air pressure test

At present, transformers are tested by filling them with dry air to an overpressure of 200–300 mbar. This pressure is maintained for several hours to check for any pressure drop, which indicates leaks. A higher test pressure is not possible due to the transformer’s construction. Components such as pressure relief valves, cooling fins and certain joints cannot withstand higher pressures. If a pressure drop is detected, a soapy water solution is used to locate leaks. All joints and connections are checked manually. The formation of air bubbles indicates a leak. 

This method is:

  • Very labour-intensive
  • Time-consuming
  • Prone to error, particularly with large transformers

It is therefore the case that leaks only become apparent once the transformer has been filled with oil and is operational.

Ultrasonic leak detection on depressurised systems with CS INSTRUMENTS

CS INSTRUMENTS has over 20 years’ experience in ultrasonic leak detection. This technology makes it possible to detect leaks without the system needing to be on overpressure. 

A compact ultrasonic tone generator is placed inside the transformer, requiring only an opening of 8 cm in diameter. Bespoke solutions are available for smaller openings. The sound source emits a powerful ultrasonic signal in multiple directions, which propagates throughout the entire transformer. An ultrasonic leak detector can then be used on the outside of the transformer to easily determine where leaks are located. Where a leak is present, the ultrasonic signal escapes and is detected by the leak detector responding to the ultrasonic tone.

Advantages of this method:

  • Leak detection from several metres away  
  • Fast and accurate localisation  
  • Option for visualisation and documentation (depending on the device)  
  • No pressure required → safe for all components  
  • Significant time savings: from days to minutes

Thanks to this approach, a complete transformer can be checked for leak-tightness quickly and reliably, with a significant reduction in working hours and the risk of missed leaks.