The Off-line Fault Diagnosis Research And System Development On Rotor Winding Inter-turn Short-circuit Of Turbine Generator

With the development of the society,the capacity of the electric power system is getting larger to satisfy the increasingly larger need of electricity.The capacity of the generator is also larger and larger.Once the generator breaks down,it will have a bad influence on electric power system.Therefore,it is very important to diagnose whether the generator is fault.Rotor winding inter-turn short-circuit of generator is one of the most common fault.Therefore,it is very important to find ways to diagnose the fault quickly.(1)This dissertation analyses the variation of the rotor AC impedance after a field winding short-circuit fault.The rotor AC impedance test is conducted on the fault simulation generator and the Maxwell simulation model of generator.The rotor AC impedance is calculated under the condition of various degree of field winding shortcircuit fault and the fixed position of the rotor.The changing rules of the rotor AC impedance were analyzed.(2)This dissertation analyses the variation of the static equivalent circuit of the generator after a field winding short-circuit fault.with the principle analyzed and the formula derived for the stator AC impedance,a way to diagnose field winding shortcircuit fault by using the AC impedance of the stator is proposed.With the aid of shortcircuit fault simulation test on generator under the condition of rotor winding opencircuit and rotor winding short-circuit,the AC impedance of the stator can be calculated at different short-circuit fault conditions and rotor position.The changing rules of the stator AC impedance were analyzed.(3)With the aid of LabVIEW,the rotor winding inter-turn short-circuit fault diagnosis system is complied.The voltage and current signals is changed by transformer,which are collected by the data acquisition card of PCI8622 with the help of PCI Bus,those signals are transmitted to the LabVIEW fault diagnosis system to determine whether the generator rotor winding is at inter-turn short-circuit fault condition,which can process,analysis and display those signals.