The substation is an important part of the power transmission system, and the transformer is one of the core equipment of the substation. During the operation of the transformer, the internal voltage of the transformer often fluctuates sharply due to the change of the load. When the voltage is high enough, it will cause the insulator in the appliance to ionize and discharge. When the partial discharge develops to a serious stage, the solid insulating material and transformer oil quickly decompose, which will cause the entire insulation system to be broken down and cause the transformer to fail. Therefore, any discharge phenomenon in an operating transformer should arouse people's attention.

Partial discharge in transformers is always accompanied by high-frequency current pulses, electromagnetic radiation, sound, light, heat, and chemical processes. Acoustic emission detection, as a common partial discharge detection method, is a dynamic non-destructive detection. Method, it can perform online real-time or continuous monitoring of transformers, the main advantages are:

1. High real-time. Acoustic emission has a very high response speed, which can capture and distinguish every transient partial discharge pulse.

2. Strong tracking. Acoustic emission has a strong endurance capability, and can track changes in partial discharge over a long period of time (such as months and years). It can reveal when the partial discharge occurs (to milliseconds), the time period during which the partial discharge occurs every day, and the strength of the partial discharge signal.

3. Automatic recognition of partial discharge signal characteristics. On-site monitoring will inevitably encounter a lot of noise. This is especially true in the all-weather, changing conditions of the four seasons.

4. Three-dimensional automatic positioning of the partial discharge source. An important feature that distinguishes acoustic emission monitoring from other technologies is that it can be used for three-dimensional positioning of the partial discharge source. Through positioning, it can help users find and analyze the source of the fault and the possible degree of damage, and accurately and conveniently propose solutions to the fault.

5. It does not affect the normal use of the transformer. There are some partial discharge monitoring methods that can only install sensors when the transformer is out of use, or repair and maintain the monitoring system, but for acoustic emission technology, it can be installed, debugged, and operated completely when the transformer is running. use.

Due to the advantages of acoustic emission technology, partial discharge can be monitored on-line around the clock, and users can view the monitoring results of each transformer at any time.