The causes of hydro-generator shaft voltage and shaft current

The causes of hydro-generator shaft voltage and shaft current 2018 - 11 - Reasons: 11 shaft voltage and shaft current generator in the process of turning, as long as there is unbalanced magnetic flux chain on the rotating shaft, are the ends of the shaft of the generator can produce induction electric potential. The induction electric potential is called shaft voltage. The main shaft voltage can be divided into two parts: 1. Rotating shaft in rotary cutting unbalanced magnetic flux in the shaft at both ends of shaft voltage; 2. Because of the axial magnetic flux leakage and on both ends of rotor shaft voltage. Caused by unbalanced generator field, and then the reasons of the shaft voltage has three aspects: ( 1) Due to causes such as manufacturing and installation technology of the magnetic circuit is not balanced and the asymmetry of the air gap, this is inevitable. ( 2) Generator internal or external shaft voltage asymmetric short circuit occurs. Part this is because of the stator winding short-circuit induced current, it prevent synthesis of magnetic flux through this part of the winding of the stator area; And at this point, not of the stator winding short-circuit parts but no this phenomenon, this effect with the stator asymmetric equivalent magnetic circuit, produce axial alternating magnetic flux is given priority to with the fundamental frequency. If the lead is located in the generator stator winding length direction, the left and right sides of the asymmetric external short circuit may also produce shaft voltage. ( 3) Excitation loop grounding or rotor winding interturn short circuit also can produce strong axial magnetic flux imbalance. When shaft voltage reaches a certain value, through the current closed loop that produces such as bearings and its base, the current is called shaft current. When shaft voltage reaches a certain value, through the current closed loop that produces such as bearings and its base, the current is called shaft current.