Discharge Quantity Inversion Method in GIS Based on Ultra-High Frequency Signal through Digital Simulation

Estimating the severity of partial discharge is a critical step in diagnosing faults of power equipment. The pulse current method using apparent discharge quantity to describe the discharge level is widely used. However, this method’s detection frequency range coincides with strong electromagnetic interference in the field and relies on offline test circuits, making it difficult to achieve online monitoring of electrical equipment. Therefore, this paper proposes a method of inverse calculation of discharge quantity based on digital simulation of ultra-high frequency (UHF) signal. Through digital modeling and simulation of power equipment and corresponding insulation defect, the relationship between partial discharge faults and UHF signals can be obtained. Based on that, the inverse formula is deduced to calculate the discharge quantity. Compared to the traditional technology, the proposed method doesn’t need the physical high-voltage test which could be more suitable for online application to evaluate the severity of power equipment.