Calculation Of Magnetic Field In End Zone Of1000MW Hydro-generator At Operation Under Leading Power Factor

In recent years China’s power grid construction got great progress and rapiddevelopment. At present, the large capacity units and high-voltage level of powernetwork in China has been a notable feature. With the increment of long distancehigh-voltage transmission lines and the high voltage electricity line voltage level, thereactive power were surplus in the system. Owing to this surplus, This will lead tothe network voltage rise even more than the system of running voltage rating, whichnot only affects the quality of power supply voltage, still can make the power gridloss increased, and the electric energy is debased. With the large scale of the systemis continuously increasing, and this problem will become more prominent.In order to solve this problem, engineering and technical personnel had a lot oftheoretical research and experimental work. Installation reactors, SynchronousCondenser or Static VAR Compensator on the power Plant or transmission Line is aneffective measure to absorption system reactive power and reduce the system voltage,but there are shortcomings to increase capital investment and operating limitations.In recent years using synchronous generators operation under leading power factor tosolve the problem of surplus system reactive power received extensive attention andapplication. Unfavorable factors such as stability decreases, heating of stator end andTerminal Voltage would threaten the safe and stable operation of power generationunits. In this paper, end magnetic field is researched deeply when1000MW hydro-generator working at operation under leading power factor.This thesis first introduces the background and significance of the1000MW hydroelectric generator, a detailed analysis of the significance of the end magneticfield1000MW hydro-generator working at operation under leading power factor.Then, the2D model of1000MW hydro-generator is built based on the finiteelement software. The field currents are calculated at no-load and rated load inconsideration of the differences of various parts in the axial length, and determinedthe excitation current in different leading phase condition.For improving the calculation accuracy of the hydro-generator end magnetic field,a3D finite element model of the1000MW hydro-generator in the end region wasestablished which was fully considered the actual structure of the hydro-generator.Based on the theory of transient electromagnetic field, the distributions of theflux density in end structural are got at no-load, rated load and different leadingphase condition. At the same time, the distributions of eddy current and the eddycurrent loss in the end structural components are got.