Research on the state monitoring method of ultra high voltage transformers based on built-in sensors

Abstract An AC ultra-high voltage transformer is one of the core equipment in the power system. However, there are still some issues with the existing monitoring technology for ultra-high voltage transformers. Although the application of external ultrasonic partial discharge sensors has improved monitoring capabilities, such sensors generally have certain defects due to the interference of the operating environment and electromagnetic noise. In response to the above issues, this article proposes a state monitoring method for ultra-high voltage transformers based on built-in sensors: a built-in multi parameter partial discharge sensor is developed, which can perform multimodal collaborative monitoring of transformer discharge faults; A signal processing method based on an improved wavelet threshold adaptive algorithm is proposed, which significantly enhances the ability to extract weak discharge signals under strong noise; And comparative experiments have shown that this method can effectively improve the sensitivity of partial discharge monitoring without changing the distribution characteristics of the electromagnetic field inside the transformer.