Design And Application Of High-voltage Auxiliary Power Supply System Of The Power Plant In Xiaomo

For the stable and safe operation of the power plants,the reliable operation of power plant system should be ensured.When the power load of the plant may not work in an orderly manner or a serious fault occurs,reliably supplying power to the power grid with high quality can be quite difficult.Therefore,the design of a reasonable and reliable electric power plant system and the connection mode of the working power supply is quite important to ensure the normal and reliable operation of the power plant.Taking the power plant in Xiaomo as an example,this paper studies its design of station service electrical system.The evaluation system based on analytic hierarchy process(AHP)is established for the comprehensive evaluation of the design of the power plant in Xiaomo.The work of the paper is mainly summarized as follows:(1)Based on the AHP,an evaluation system for the electric wiring scheme of high-voltage power plant is established.Firstly,the basic theory of AHP is introduced and explained its adaptability evaluation of plant power system.Further,the evaluation of wiring scheme model in power plant is proposed.Considering three level indicators including the technical level,economic benefits and environmental impact,a detailed evaluation index scheme is established.The evaluation model established is relatively comprehensive,thus it can be used for evaluation of the connection plan of auxiliary power.(2)In this section,AHP model is used to evaluate the proposed four candidate connection schemes.Firstly,the basic principle of voltage level and power supply connection for auxiliary power system is introduced.Combined with the actual engineering situation of power plant in Xiaomo,four candidate wiring schemes are proposed and designed.Further,the electrical performance of the scheme is analysed from the short circuit current,voltage fluctuations and other aspects.Besides,the performance from technical and economic aspects is also provided.According to the specific conditions of the four wiring schemes,we use the proposed AHP model to determine the optimal wiring scheme.(3)The selection of related electrical equipments is carried out on the basis of the wiring scheme which is designed above.According to the actual situation in Xiaomo and the power plant industry standards,we design the type,cooling mode and voltage regulation mode of the main transformer in Xiaomo.Besides,the selection of other related equipments,such as voltage transformer,current transformer,lightning arrester and isolating switch is also carried out to further improve the design of the electrical system in Xiaomo,which makes the design more feasible.(4)In this section,the design and inspection of the power supply fast switching system are discussed.Combined with the actual engineering situation of the power plant in Xiaomo,the wiring scheme of fast switching power supply is preliminarily designed from the aspects of economy and reliability.Further,three candidate schemes based on the above wiring scheme are designed.The AHP model for the comprehensive evaluation is established from the aspects of economy,reliability,flexibility and extensibility,which can be used to determine the optimal scheme.Finally,we test the fast switching system from the normal function,basic function and switching function.The results of related design imply that,the design scheme of the plant power system proposed in this paper is reasonable and scientific.