Partial discharge detection is an important means to find out potential insulation defects of high voltage power equipment and to carry out quality control. For the sample of capacitor

due to the limitation of capacitance and electromagnetic interference

the test result of both traditional pulse current method and ultrasonic testing method have some limitations. In this paper

according to the characteristics and requirements of delivery partial discharge detection of capacitor

a new type of high frequency partial discharge detection method of current is studied and developed. This method is based on differential balance wiring mode

a combined denoise method of the combination of dual channel pulse polarity identification and UHF noise sensor is proposed with purpose of improving the sensitivity of the partial discharge detection under strong electromagnetic interference condition. The corresponding special measurement system is developed and the actual application result of the method is proved by way of site test.The results show that the method is able to achieve the delivery partial discharge detection of capacitor under strong electromagnetic interference.