Development of low cost ultrasonic listening device for partial discharge detection: Part II

This paper describes the continuity of the development ultrasonic listening device that capable in capturing the ultrasonic sound produced by discharges in the insulation. The device is designed using the wideband amplifier that provides a wide bandwidth range that covers from 10 Hz up to 100 kHz. The design of the device has been improved by adding the parabolic reflector. With this improvement, the detection sensitivity is increased up to 160 centimetres, therefore, the device able to detect the discharges for underground cable. In standard detection procedure, the power system needs to be offline in order to assemble the detection device such as sensors prior to the detection process. This device will be an added value compared to the conventional device; where the detection work can be done while the power system is still online. Moreover, the method of detection is purely a non contact method; without any detection device such as sensors to be attached to the affected insulation. Besides it is low in cost, this device promise a simple and practical usage to the users. To the extension of the design, this device can be used to detect partial discharge in the insulation of overhead power cable and underground cable without having to dig out the cable.