Research And Engineering Application Of Intelligent Ultra High Voltage Frequency Convertion Resonant Test Power Supply

High voltage test is an absolutely necessary tache before putting transmission line into service. With the rapid development of ultra high voltage grid in our country, it seems especially important weather the ultra high voltage field test can be accomplished successfully. Developing a test power supply applicable to ultra high voltage grade and easy transported is imperative under the situation. At present, the high voltage test power sources of our country mainly includes high voltage test transformer and resonant ac-testing supply. But due to their huge volume, difficult to transport, lower voltage grade and they don't have a rapidly response protecting circuit, they hardly meet the needs of ultra high voltage field test. The development of this device has great meaning for decreasing the expenses of ultra high voltage transmission construction and realizing grid upgrade.Firstly, this paper discussed the characteristics of ultra high voltage transmission and the necessity of the putting it into practice in our country. Traditional high voltage experiment and its test supply are analyzed, and the exist problems of the power supply are proposed at the same time. Combined with project practical demands, the design requirements for intelligent extra high voltage variable frequency resonant power supply is proposed.Then, on the basis of analyzing design requirements and combining with practical demands, a integer configuration of novel serial resonant extra high voltage testing supply based on DSP is proposed. Moreover,a sine wave generator based on DDS frequency changing technology and control algorithm for voltage, frequency regulation are brought forward, which have the characteristics of rapid response, good waveforms and lower aberration rate. Aiming at the small power of traditional resonant testing power supply, this paper put forward a source amplification cabinet provided with bridge type power amplification circuit and its output power can achieve 600kW. Fiber undistorted technology and its application to ultra high voltage field experiment are also introduced in this thesis, so the problems of high electromagnetic interference in testing field and hard to measure feedback voltage are solved.Moreover, development means as well as loss calculation for each parts in resonant loop of extra high voltage level are proposed. Making methods and parameters of extra high voltage reactor are introduced in detail. At the same time, from the aspects of power loss, partial discharge quantity and withstanding voltage level, various components suitable for extra high voltage resonant loop are researched, including excitation transformer, ultra high voltage resonant reactor, extra high voltage resonant capacitor and equalizing ring, also the request of its parameters are suggested.Besides, in order to have a overall understanding of the parameter performance of each parts and the device itself, also to insure the device safely steady operating, an comprehensive type test about ultra high voltage power source is carried out in this paper. Fission test is done before the integer test. In fission test, performances and parameters of intermediate excitation transformer, high voltage resonant reactor, compensation reactor, high voltage resonant capacitor and 600kW power frequency modulation cabinet are tested. The measurement of integer character factor of the device, harmonic factor and voltage withstanding properties are included in integer test.At last, through two field experiments, partial discharge test of 1000kV ultra high voltage transformer in Hengyang transformer factory and 1000kV GIS withstand voltage test in Jinmen, Hubei province, the performances and field feasibility of the device are powerfully validated.