Condition monitoring Essay Example | Topics and Well Written Essays - 1500 words

Condition monitoring - Essay Example Common electrical components like transformers and power cables are tested for partial discharge as part of a quality assessment framework. In fact, detection of partial discharge is a common practice adopted by electrical manufacturers across the world since the 1980s. Testing for partial discharge is necessary to improve the quality and reliability of electrical systems, as it has been cited as one of the primary reasons for failure of electrical systems (Bengtsson, 2003). The presence of partial discharge indicates a partial damage to the insulation that can lead to speaking effects along the insulation surface. Thus, detecting partial discharge helps in the identification of flaws like cracks and voids where there is a maximum probability of electrical stresses that can lead to a breach of the insulation. The analysis of partial discharge can be carried out using several predictive tests that identify any degradation of the insulation before such a condition leads to the damage o f the system. Such testing can further be carried out in standard operating conditions and does not require any special arrangements. Zhiqiang, (2004) says that typical methods of detection include acoustic, electrical and chemical techniques that do not affect the insulation system. Besides, all these methods for detection can be undertaken at reasonable costs and thus find widespread acceptance in the industry. This paper discusses the acoustic method of partial discharge (PD) detection by describing the advantages and disadvantages of the technique. Further, data has been sourced from 6 different research papers that analyze the acoustic PD method from different perspectives. Discussions and inferences from these individual papers has been presented and compared wherever appropriate. Possible future trends for acoustic PD testing have also been discussed in brief. Acoustic detection of PD Blackburn (1998) says that the acoustic method for PD detection relies on the identification , processing and storage of the signal resulting from a partial discharge. The acoustic signal generated during a PD occurrence is detected and recorded by the acoustic PD testing arrangement. The technique is similar to the generation of thunder during a storm. The acoustic signal is generated when a current streamer develops within the void space. The material surrounding this volume becomes vaporized leading to an explosion that releases a detectable amount of mechanical energy. The released energy then travels along the electrical system’s volume as a pressure field. The acoustic PD detection technique is mostly used in gas-insulated substations as well as in High-voltage transformers. Detections systems that employ this method are also differentiated based on their construction, into internal and external acoustic PD systems. Internal PD systems consist of a sensor that is placed within the transformer tank to detect the magnitude of the pressure wave through the oil med ium. In contrast, external PD systems are based on sensors that are attached to the outside wall of the transformer tank to monitor the pressure wave. Amongst these two methods, the external PD systems are more widely used in the industry due to the ease of construction and operation (Darley, 2001). The main benefit of the acoustic PD detection method over other available techniques is that the information on the position of the PD can be retrieved instantly from the PD detection system through