Grounding system of flux adjustable arc extinguishing coil

Abstract

The invention discloses a grounding system of a flux adjustable arc extinguishing coil, and relates to the technical field of power grid protection. The grounding system comprises a monitoring system,a flux adjustment unit, a mutual inductor and the flux adjustable arc extinguishing coil, the mutual inductor detects zero-sequence voltage and current data of the power distribution network and transmits the zero-sequence voltage and current data to the monitoring system, the monitoring system monitors running condition of the power distribution network according to the zero-sequence voltage andcurrent data, and when the monitoring system determines that a single-phase grounding fault occurs in the power grid, a signal instruction is sent to the flux adjustment unit, the flux adjustment unit is controlled to input a DC for coil control, the magnitude of the zero-sequence magnetic flux in the arc extinguishing coil is adjusted, and further the capacitance and current of the power distribution network are compensated.

Description

technical field [0001] The invention discloses a grounding system for a magnetism-adjusting type arc-suppression coil, and relates to the technical field of power grid protection. Background technique [0002] my country's medium-voltage distribution network generally adopts the low-current grounding method. This grounding method does not form a short-circuit circuit when a single-phase ground fault occurs, and only generates a small-amplitude zero-sequence current in the system. The voltage between the three-phase lines is still symmetrical and does not affect the normal operation of the electrical load. The operating cost is reduced, and on the other hand, the reliability of the power supply system at this level is also improved. [0003] However, with the gradual increase of the cable network in the modern power grid, the single-phase grounding capacitive current of the medium-voltage distribution network is increasing sharply. When the system capacitive current is great...

AI Technical Summary

Problems solved by technology

When a single-phase ground fault occurs in the power grid, the control system short-circuits the resistors to achieve the best compensation effect. However, the arc suppression coil of the follow-up compensation cannot be adjusted online with power on, and the adjustment range is limited. The effect of smooth adjustment cannot be achieved. And adjust the response speed is slow and other issues

And because the 6-10kV sides of my country's power grid transformers are connected in a delta, the arc suppression coil of the existing structure generally cooperates with the grounding transformer, that is, the arc suppression coil functions through the neutral point of the grounding transformer and the power grid, and the grounding In the process of compensating the capacitance current of the power grid to the ground, the transformer only transmits the zero-sequence inductance capacity of the arc suppression coil, but consumes the no-load and load losses of the two power devices, which is not conducive to energy saving and environmental protection, and the complete set of equipment occupies a large installation space , high cost

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