GROUND FAULT PROTECTION METHODS

摘要

A power distribution system (1") is described. The power distribution system (1 ") comprises a plurality of power converter systems (21-24) electrically connected to a distribution bus (5) which defines a point of common coupling. Each power converter system (21-24) includes a power converter (31 -34) with a plurality of semiconductor switching devices controlled using a PWM strategy with a switching frequency. A controller (121-124) for each power converter system (21-24) is provided. Each controller ( 121-124) is adapted to apply a spectrum analysis process to the respective power converter system that uses measured or derived zero sequence currents associated with the respective power converter system to determine the location of a ground fault within the power distribution system. Each controller (121-124) is adapted to apply a switching frequency process where the switching frequency of the power converter of at least one of the power converter systems is different from the switching frequency of the power converter of at least another one of the power converter systems during at least part of the time that the spectrum analysis process is applied.