Insulation failure prediction in induction machines using line-neutral voltages

摘要: This paper presents both the experimental results and a simple theoretical validation of novel technique used to detect turn faults in single phase stator an induction machine. The algebraic sum three instantaneous line-neutral voltages is shown readily identify occurrence insulation fault. Since this contains frequency components due core magnetic saturation, slot harmonics etc., detection sensitivity can be greatly improved by removal these frequencies band-pass filtering around fundamental. As relies on deviations impedance balance occurring during faults, not changes average values-attributable differing normal operating conditions-the largely immune varying load conditions, temperatures source voltage perturbations. Furthermore, it that only free relatively complicated calculations, but expectedly more so numerical errors comparison existing techniques based upon accurate sequence calculations current. simplicity allows low-cost analog or digital implementation wherein fault reliably detected within cycle fundamental machine excitation.