Heavy Load Analysis And Design Of 110kV Seven Star Transformer Substation

The substation, being a part of our country's electricity system, plays an important role in the region's economic development and life demand. Based on the analysis of the current circumstance lying in the New Town and Zhouxin district of Qingyuan city, this paper summarizes the issues of substation overburden because of the request of the city development and the increasing demand of electricity. The population density of New Town increases year over year, and its population will become larger than the old district in the next 5 years. Moreover, it will become the rapidest development district of Qingyuan city. Meanwhile, Zhouxin district starts to build up Yanhu New Town, which will become the city center in the future. If all the electrical load also distributed into Seven Star substation, it can't provide support to the load demand of the future.According to the geographical location of the New Town and Zhouxin district, especially the New Town, which is the center of politics and culture, this paper will define the design principles after taking safety, economy and reliability into consideration. Therefore, during the process of designing the substation, it will apply to the demand of “The General Design Principles Of 110 k V Substation” from the very beginning to the end. What's more, the design will be updated and improved with the development of Yanhu New Town.The major model will not be selected until making the analysis of the increasing trend of 110 k V substation load in the recent two years and figuring out the whole capacity in the next 10 years based on the theoretical calculation as well as comparing the advantages and disadvantages of different models.As to the option of connecting manner, the substation should meet the demand of supply reliability, daily maintenance and operation, saving investment and fasten the access to the further development. The best connecting manner will be selected combining the major wire connecting technology in the current domestic 35 k V—110k V substation and following the rules of “The Standard Design Of 110 k V—500k V Substation OF China Southern Power Grid”---the compared analysis of 110 k V main connecting wire “Double bus scheme ” and “Sectionalized double-bus configuration”, as well as 10 k V connecting wire “ Double bus scheme” and “Sectionalized configuration ”. Moreover, the choice of electrical equipment in the substation, should consider the problems of short-circuit happened in different operational processes and calculate the short-circuit current to avoid the damage of electric. The electrical equipment technical parameters should be decided combining the analysis the future load capacity and confirmation of dynamic stability and heat stability.Last but not the least, through removing some of the 10 k V electric cable of Seven Star substation to the newly built substation, it will share 110 k V load of Seven Star substation and spare some space. According to the development requirement, the newly built substation will take over certain load of the new town and plan out enough space for the future 5 to 10 years development. The new substation should be located nearby Seven Star substation, which helps easily classify the load of New Town and Zhouxin district, and also further assure the supply reliability between substations under the construction of substation networking. The design proposal of substation will define the connection method between stations which follows the design principles. The electric power main connection plan will be formed finally with the design above.