Design And Apply Of The Transformer RVM Measurement And Diagnosis System Software

Transform is the key equipment to convert and transmit the electric energy in the power grid, and it’s of great significance to ensure the safe operation of the power grid and avoid the large-scale power outage. So far, the routine transformer measurement methods such as insulation resistance measurement, resistance absorption ratio measurement and so on have some shortages, they can’t diagnose and analyze the transformer insulation state accurately and roundly. As one of the dielectric response measurement metohds, return voltage measurement (RVM) is a new measurement to diagnose transformer insulation state, it has many advantages such as strong anti-interference and nondestructive measurement, but at present, there is no set of measurement instrument based on RVM in China, and still lacks a method to diagnose transformer insulation state based on RVM.This paper develops the Transformer RVM Measurement And Diagnosis System software according to the site condition and requirement of return voltage test, which can make the RVM measurement process (charging process, discharging process, collection process) automatically complete, and it can filtrate the measured data, filtering out the noise disturbance and the frequency voltage disturbance, then it will calculate the return voltage parameter based on the return voltage curve which is measured, and the softwave can also save the data and the test parameter to database.To analyze the relationship between return voltage and oil-paper insulation, this paper sets up a testing platform for RVM experiment, this paper obtains the varying regularity between the oil-paper insulation and the return voltage by testing oil-paper insulation samples which are in different degree of aging or damp. And according to the measuring parameter which is seted by the independent development instrument-Transformer RVM Measurement and Diagnosis System (charging voltage is 800V, charging time is 500 seconds, the ratio of charging time to discharging time is 2), this paper proposes a method to evaluate the transformer insulation state qualitative and a method to evaluate the water content in oil-paper insulation system of transformer.In the end, we measured two transformers in Guangdong Power Grid Corporation FoShan Electricity Authority using Transformer RVM Measurement and Diagnosis System on offline, through comparing their return voltage that is measured, we evaluated their insulation state, and the applying result shows that Transformer RVM Measurement and Diagnosis System software can apply to transformer field measurement based on f return voltage method, and it has a accurate diagnosis result.