Regulation of quality of supply - an innovation driving force? Novel equipment for reducing customers' interruption costs by bypassing switches during maintenance

The paper deals with localization of phase-to-phase shortcircuits on a medium voltage (MV) feeder with distributed generation (DG). Fundamental frequency currents and voltages are utilized for estimating the distance to the fault location. Loads and DG connected to the feeder cause errors in the estimated distance. Two methods to compensate for these errors are presented in the paper. Incompensation method A, pre-fault measurements from the DG-unit are utilized for estimating the DG-current during fault. In compensation method B, the magnitude of the DGcurrent and –voltage during fault is measured. A method for utilizing the DG-node measurements to discriminate between faults on the main and on a lateral branch is also presented. The goal is to obtain sufficiently accurate fault localization with limited information from the feeder available. Copyright IET