Redundancy Characteristics Analysis of Diode Open Circuit Fault in Multiphase Annular Brushless Excitation Machine for Nuclear Power

The rotating rectifier of the multiphase annular brushless excitation system is a key component to ensure reliable power supply for large capacity generators. On site rotating diode faults often occur, causing significant damage to the power system. In order to improve the fault strategy of system unified tripping caused by different types and degrees of diode faults, this paper deeply analyzes the fault variation law of diodes, derives the thermal equivalent current of diode current under different fault modes, reclassifies the fault modes according to the magnitude of the thermal equivalent current of diodes, and adopts redundant alarm or shutdown strategies for different faults, which can improve the elasticity of the power grid and reduce the economic losses of system shutdown maintenance.