Simulation And Study Of The Large Hydro’s Field Winding Turn To Turn Short-circuit

Large hydro’s field winding turn to turn short-circuit fault affect the normaloperation, through the multi-loop method the field winding turn to turn short-circuitfault is calculated, obtaining the fault current waveforms and analysis thecharacteristics, according to the characteristics of the stator and rotor current, to helpthe protection program selecting.In the dissertation, the multi-loop mathematical model is based, by calculatingthe coefficient of gap permeability, drawing the single coil inductance, the windingconnection forms is based, a single coil inductance formed the branch inductanceparameter, after conversion between branch and loop, getting the loop inductanceparameter. After the field winding short-circuit fault, the dimension of inductors,resistors, voltage matrix have increased, parameters need to be recalculated. Thelarge hydro field winding short-circuit fault’s transient is focused on research, partialinduactance formula of the inductance matrix is described simply, at he same timeusing equivalent coefficients to adjust to affection of the generator’s saturation andcogging. A relatively common procedure is written, the short-circuit fault ofnetworking no-load conditions were simulated, harmonic analysis to get close to thefundamental frequency’s harmonics amplitude large, fault characteristics issignificantly. The field winding short-circuit fault of different turns is simulated,through comparative analysis the fault current trends are appeared, results are inagreement with the theoretical. The field winding fault’s effection of small turn is notlarge, but, after the fault expanding, it would have serious consequences, for theshort-circuit fault of a small turn, finding the characteristics of the fault, providingthe basis and assistance for the combination of protection programs.Also prone to problems and corresponding solutions are simple described in the preparation process, some references are provided to initial and step selection insolution of differential equations.