Mathematical model and diagnosis of rotor fault in synchronous condenser

Abstract

With the application of new energy in grid-connected system and the development of UHV DC transmission, the grid's requirements for reactive power regulation have gradually increased. Considering that, large-scale synchronous condensers have been put into use again. However, it is difficult to extract the characteristic signal of the inter-turn short-circuit fault in rotor windings of synchronous motors. In order to improve the stability of condensers, a certain relationship between the excitation current and the number of turns is derived using the Parker equation in the dq0 coordinate system, and the differential equation simulates the excitation current. Then the characteristic energy value of the fault signal is extracted through wavelet packet decomposition and reconstruction, and it is input to the RBF neural network for fault diagnosis. It is proved by MATLAB simulation that the diagnostic method proposed in this paper can effectively detect the degree of short-circuit faults between the turns of the rotor in condensers.