Abstract
The design is made up of four parts: part one, the design specification; part two, the prospectus of the design and the calculations of the design; part three,construction of power substation; part four, the design drawing.
The design concerns a step-down substation of three voltages with the main capacity of 2X31.5MVA. Its main line of 110KV is a two-way bus, and the other two of 35KV and 10KV are both one-way bus line sections. As for the design, the thesis has verified its wiring project, calculated its short-circuit current, selected and tested its main electrical equipments like the circuit breaker, the disconnecting switch, the bus line, PT, CT, etc.
I would like to express my thanks to the supervisor, Mr. for his invaluable assistance. Since this is a tentative design, the criticism and advice of all my teachers and schoolmates are welcome for its improvement.