Protection from single-phase earthings overhead and cable lines 6-35 kV distribution networks

摘要

The security device of single-phase earth fault overhead lines and cable distribution networks 6-35 kV power direction comprising a body consisting of matching current transducers and voltage transformer type, two low-pass filters, two filters emergency components, comparing a current and voltage circuits characters, two monostable multivibrators, the two elements of the ban, and the starting body consisting of industrial frequency filter, one element prohibition voltage relay and comprising aND gate, a time element, two output relays, the input matching inverter transformer type connected to the secondary circuits of the current zero-sequence current of the protected line, and output via a series-connected first filter emergency constituting the first lowpass filter connected to the first input of comparing a current signs circuit and voltage input matching voltage converter type transformer secondary circuits coupled to the voltage zero sequence section (system) busbar, which is connected to defend th line, and the first output through series connected second filter emergency components and a second low pass filter coupled to the second input of the comparison current signs circuit and voltage, the second output matching inverter transformer type voltage through the filter discharge power frequency connected to the input voltage relays, whose output is connected a first input aND gate and through the first barring member connected to the input of the first monostable ban, the first output current comparison circuit signs and Port voltage