Numerical Calculation Of Electric Field Distribution In Stator Bar Of 1000MW Turbo-Generator

Generator with larger unit capacity has better economical performance, but will cause lots of unfavorable factors to the operation stability of generator insulation system. The insulation state of generator stator windings is very important to the safety, protracted and economical operation of the generator. The electric properties of insulation which is a key issue of the insulation state, is very important to the Safe operation of generator. In order to improve the performance of winding insulation, more attention must be paid to the insulation structure of the windings to eliminate the partial discharge and corona, which happens in the insulation materials.Because the distribution of electric field at the corner and end of generator stator windings is nonuniform, it is easily to cause partial discharge and electric corona. So, in this paper, the ANASYS software was adopted for the FEM simulation and calculation of 1000MV Turbo-Generator Stator Bar, then, Tina Pro was used for them on the Stator Bar equivalent circuit, the optimization scheme of stator bar corner structure, end anti-cornoa structure and contact point distance were given too.The following results can be concluded from this paper. First, when the fillet of the conductor is 2mm, the field strength distribution of the stator bar is improved obviously, that the maximum field strength is reduced from13.2kV to 8.65kV below and the uniformity coefficient fell to 1.99 below from 3.03, both of which have a decline of 34.47%. Second, in this paper, the CMATRIX command of ANSYS was used to calculate the body capacitance and surface capacitance of the end of the winding and then, The Tina Pro software was adapted to analyze the equivalent circuit, which has the practical significance in engineering applications. Using the simulation method, the validity of the data given by the electric machinery corporation was verified, the result is that the concentrated electric field in the slot has been processed to the place far away from the slot, and the electric field strength fell significantly compared to the original state. Meanwhile, the resistance of anti-cornoa structure was adjusted to improve the electrical field and potential distribution of the end of stator bar, and the best optimization scheme was given. Third, the same method as above was used for the simulation of the equipotential layer structure in stator bar. The simulation results show that it will be best where the distance between the contact point and the equipotential layer is less than 300mm.