Condition Monitoring of High Voltage Equipment


  • S. Yub
  • M. F. Hussin


Electrical system network comprises of generation, transmission line and distribution substation. A power generated from the generation station will be transferred through transmission line to the distribution substation. It involved a lot of main components such as transformer. Transformer is used to regulate the voltage by stepping up a high voltage and low current to sustain the power transformer. In order to do this, the power transfer within primary and secondary windings of the transformer must be approximately equal for better transmission unless there is losses in the transformer. The losses in the transformer are non-load and load losses. Non-load losses are minor losses in the transformer because it not varies to the loading of the load. It is an internal reaction due to the magnetizing current that energized the core of the transformer which produced core losses, stray losses, hysteresis losses, stray eddy current and dielectric losses [1]. On the others hand, load losses are due to eddy current and heat losses. These two losses contributed a significant loss in the transformer due to friction and heat created from the resistance winding resulting the flow of the current that can breakdown dielectric strength of the insulating oil inside the transformer. The insulating oil is used as an insulation system consist three main properties such as electrical, chemical and physical properties. Hence, the insulation oil is said to be serviceability when all the criteria needed is fulfilled. Therefore, the criteria in dielectric strength of the insulating oil is tested using standard oil test equipment based on the setting of the breakdown voltage indicate there is no moisture content and conducting substances in the insulating oil. The insulating oils used in the transformer required periodically testing, hence it has created the baseline properties of the insulating oils that needs to be studied and the data obtained can provide a valuable information to overcome any cause or losses that shorten the life span of the transformer.