Stable status zero-sequence current increase and assistance device and method

Abstract

The invention discloses a steady-state zero-sequence current boosting device and method. It solves the defect that the current method of line selection and positioning using the steady-state component of the fault signal has the defect that the amplitude of the fault electrical quantity of the system itself is small and difficult to detect. It has the ability to instantly amplify the steady-state component of the fault signal after a single-phase ground fault occurs in the grid Make the line selection and positioning device based on the steady-state quantity of single-phase ground fault operate accurately, and achieve the advantages of positioning and line selection. Its structure is: it includes the busbar of the protected power distribution system, and the steady-state zero-sequence current The booster device is also connected to the voltage transformer, and the voltage transformer is connected to the busbar; the booster device is composed of a power capacitor bank, a switching switch and a control device. The control device monitors whether a single-phase ground fault occurs in the power distribution system. The power capacitor bank boosts the ground current, and the switching of the power capacitor bank is controlled by the control device through the switching switch.

Description

technical field [0001] The invention relates to a grounding fault detection technology in a power system, in particular to a steady-state zero-sequence current boosting device and method for a neutral point ungrounded or arc suppression coil grounded system. Background technique [0002] At present, for the power distribution system in operation, since the neutral point of the system is not grounded or grounded through the arc suppression coil, no short-circuit loop will be formed after a single-phase ground fault occurs, and only a small zero-sequence current caused by the distributed capacitance of the system. Various devices for finding single-phase ground faults at home and abroad are based on these relatively small quantities as the judgment basis, and the misjudgment rate is relatively large. In this regard, there is no accurate and reliable microcomputer line selection device that can act on tripping at present. [0003] Universities and manufacturers at home and abr...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the defect that the fault electrical quantity amplitude of the system itself is too small and difficult to detect in the current method for line selection and positioning using the steady-state component of the fault signal, and to provide a method that can instantly Amplify the steady-state component of the fault signal, make the line selection and positioning device based on the single-phase ground fault steady-state quantity operate accurately, and achieve the purpose of positioning and line selection, etc. The steady-state zero-sequence current boosting device and method

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