Study On The Comprehensive Protection Of The Drive System Of Induction Motor And The Thyristor

The comprehensive protection of drive system of the induction motor and thethyristor are studies when the fault is occurred in the motor or feed circuit in this thesis.The thyristor and stator winding have different topology architecture when the inductionmotor is controlled by the thyristor. Based on the fault characteristics of the inductionmotor, the current through the thyristor and the stator winding are studied when theshort-circuit or open-phase fault is occurred. The reasonable protection method based onthe different topology architecture is given in the thesis, and the induction motor and theover-current of the thyristor are reliably protected.To solve the problem that the half-wave Fourier algorithm will bring errors whenthere is decaying DC component in the sampling signal, the thesis introduces animproved half-wave Fourier algorithm. It not only includes the function of the half-waveFourier algorithm, but also filters the exponential decaying DC component with randomdecay time constant in theory.