Survey on industry practices and effects associated with the cutting out of stator coils in hydrogenerators

Operation of hydrogenerators with cut out faulted coils is a common practice in the industry, this is often done within acceptable limits of voltage unbalance. The purpose of this brochure was to explore and document industry experience on cutting out of faulted stators coils including the cause of the faults, techniques to locate the fault in the windings, considerations for repair methodology chosen and effects or encountered problems of cut out coils.