Operational Control of the Suspended Insulations Condition of 110 kV Power Lines

Based on the damage statistics of 110 kV power transmission lines and the analysis of the current regulatory documentation, a conclusion is made about the need for electric grid organizations in a modern complex for telemetric monitoring of the suspended insulations condition. The choice of changing the voltage distribution on insulators as a diagnostic criterion is considered, on the basis of which the control system is being built. The main requirements for the voltage sensor are formulated. The choice of voltage sensors design and parameters a based on a capacitive divider using the existing component base is considered. The calculation of the sensor parameters was made using the basic equivalent circuit of the suspended insulation string, the developed design scheme of the sensor and mathematical models of the electrics field distribution along the string. Calculations confirm the possibility of registering the appearance of a defective element in a chain-string by changing the voltage distribution along the insulators string. The calculation results were verified on a computer model in the Multisim environment. The experimental part of the work represents the results of laboratory measurements of the glass plate insulators (type PS-70E) capacitances, both new and damaged. The data obtained confirm the correctness of the capacitance values adopted in the calculations. A correlation has also been established between the grain size of a glass piece destroyed during an electrical breakdown of an insulator, its capacitance and residual electrical strength.