Condition monitoring of overhead transmission line insulators
Background
Insulators in overhead transmission lines have two functions. Firstly, to mechanically support the weight of conductors and, secondly, to provide electrical insulation between the phase conductors (High voltage) and the grounded tower (zero potential). These insulators are being subjected to accumulation of different types of pollution (industrial, agricultural, sea salt, etc.). Pollution accumulation can, due to changes in surface properties, reduce the electrical performance of insulators and this may cause flashover. Flashover can cause tripping of the safety cut-outs on the line and, hence, affect line performance. Moreover the partial discharge activities which result from the change in surface properties in the presence of pollution can cause accelerated ageing of insulators, reducing their useful working life. Signals which indicate the presence of electrical discharge, or other effects due to changes in surface properties, can be employed to monitor power line insulators.
Based on this short background it is obvious that appropriate condition monitoring of insulators can give engineers information which allows appropriate remedial action to be taken. These remedial actions increase the reliability of the power network and also extend the life of insulators.
Tasks:
Obtain papers from a variety of sources, e.g. IEEE and IEE/IET journals or conference papers, which deal with methods that can be applied for condition monitoring of overhead power line insulators. From the material read, select 4 methods for discussion.
From the material gathered prepare a short report containing the following elements:
- Abstract
- The consequences of pollution accumulation on overhear power line insulators
- Discuss four selected techniques for condition monitoring of insulators :
- Discuss advantages and disadvantages of the four methods
- Comparison of data presented by the selected papers
- An indication of future trends, if any, in this field
Word count: The total report, including References, should be restricted to 2000 words.