Charge distribution measurement of solid insulator materials: A review and new approach

A reliability of electrical energy supply could be disrupted by the build-up of space charge distribution within or on the surface of insulator. Preventive measures have been carried out since the earliest days of power transmission network invented till today to alleviate the space charge effect on electrical energy systems. Although the preventive measures have been taken greatly, there are inevitable factors especially environmental conditions that lead to the accumulation of space charge. Space charge which carries energy such as kinetic, heat and other forms is believed released these energies during the space charge accumulation process and subsequently distort the local electric field. Despite the numerous papers published on space charge investigation in polymeric insulation, there is an absence of thorough review papers on this topic as well as space charge effects on glass insulation. Hence, this paper provides a summary of charge distribution measurement within and on the surface of insulators along with a new approach to measure the space charge distribution on the surface of glass insulator strings. This knowledge will provide a contribution to the development of a new online space charge distribution measurement system for glass insulator string that will be more efficient, by utilizing the available technology for data transmission. This new approach also has the capability to monitor the condition of the insulator while energized and in service, thus the faulty insulators can be replaced without disrupting the distribution of electrical energy around the world.