METHOD OF COMBINED TESTING OF THREE-PHASE WINDING OF ELECTRICAL MACHINE

摘要

FIELD: electric engineering; measuring technique. ^ SUBSTANCE: method can be used for inspecting intra-turn isolation and detecting short-circuiting in winding of stator of asynchronous electrical machines. Two pulse sequences superposition is applied to windings of electrical machine from generator with adjusted pulse duration t and delay time t3; sequences have similar periods of T and opposite polarities of pulses. Delay time t3 = tau is set between specified pulse sequences. Pulse duration tau and time delay t3 is subject to change between pulse sequences while meeting the condition of t3 = tau to reach the k-th harmonic with maximal amplitude at frequency of omega0=2kpi/T. Meaning of voltage at output of phase detector is fixed, which value is proportional to difference in phases of harmonics with number of n=k, selected from test voltage by selective units, tuned to frequency of omega0=2kpi/T. Phase windings are subject to place exchange in sequence. Presence of defect in any phase winding is judged from change in voltage at output of phase detector. ^ EFFECT: improved truth of results of measurement; improved sensitivity. ^ 3 dwg