Study On Economics Of Transformer Capacity And Operation Mode In Power Supply And Distribution Of Civil Building

In recent years, with the accelerating process of urbanization, energy demand growth was rigid, the number and capacity of civil building distribution transformer is increasing. Because of the large amount and the long operation time, so its power loss is very large. Study on economics of transformer capacity and operation mode in power supply and distribution of civil building can reduce the power loss, not only makes economic sense but also has environmental significance. The main research contents of this paper are divided into the following several aspects:(1)Firstly, the principle,parameters and power loss of transformer are introduced, and the positive effect of reactive power compensation on the capacity and operation of distribution transformers is analyzed quantitatively; Secondly, the idea of the extremum of mathematics is combined with the transformer power loss rate load characteristic curve, and the calculation formula of the transformer economic load factor is derived. On this basis, taking the comprehensive power loss as an example, analyzed the mathematical formula of the comprehensive power loss rate, divided single transformer operation area into comprehensive power economic operation area and comprehensive power best operation area; Finally, taking the comprehensive power loss as the breakthrough point, established parallel operation and separate operation comprehensive power loss load characteristic mathematical model of two-winding transformer. Using the critical point theory, calculate and derive the mathematical model.Obtains two operation modes of economic operation area critical point division method of two-winding transformer by analyzing respectively, to lay the theoretical foundation for the follow-up study of this paper.(2)According to the characteristics of the measurement of the electricity tariff in the civil building, traditional formula of TOC method has been simplified and improved. By combining the improved method of TOC with the traditional theory of load calculation and reactive power compensation in the design of building power supply and distribution, summarize and analyze the method of determining the number and economic capacity of distribution transformer in civil building. According to civil building distribution transformers operational requirements, change critical conditions for the mathematical model of comprehensive power loss load characteristics of the separate operation two-winding transformer. Based on the mathematical model curve, discussed the critical points method for the economic operation mode determination of distribution transformer in civil building from two cases. On this basis, further refinement analysis for power supply reliability of class II or I electric loads in different power supply schemes are presented, the methods of determining the economic operation mode of civil building distribution transformer in different power supply schemes are given.(3)Put Xi’an an international Mall 3# building commercial substation as an actual engineering case. By applying the method of determining the number and economic capacity of distribution transformer in civil building, selecte the number and economic capacity of distribution transformer in actual engineering substation.For the power supply scheme of the actual engineering case, using the methods of determining the economic operation mode of civil building distribution transformer in corresponding power supply schemes, analyze the economic operation of transformers in actual engineering case. Verify the correctness and practicability of the conclusions and methods of this paper by the practical engineering application.The purpose of this research is through a large number of mathematical derivation and theoretical analysis to come up with determination method of economic capacity and economic operation mode of distribution transformer in civil building, achieving energy saving and reducing power loss of distribution transformer in civil building. The methods and conclusions of this paper have referential significance for transformer design and selection in civil building power supply and distribution design.