Integrated control system for arc suppression coil

Abstract

The invention discloses an integrated control system for an arc suppression coil. A new neutral-point earthing system equivalent operation model is built; and a resonant earthing system can be precisely tuned, and neutral-point displacement voltage can be precisely controlled only by changing damping resistance connected in parallel to two ends of the arc suppression coil for two times. According to the integrated control system for the arc suppression coil, system capacitance and conductivity can be precisely measured. Meanwhile, with the method, a precise inductance value for restricting the neutral-point displacement voltage by being far away from a resonance point for a follow-tuning type arc suppression coil under an overcompensation or undercompensation state is given, and a precise susceptance value for restricting the neutral-point displacement voltage to be connected in parallel under a full compensation or non-full compensation state of a pre-tuning type arc suppression coil is also given. The integrated control system is suitable for any resonant earthing power grid system and any arc suppression coil device. The integrated control system has the advantages of wide applicable range, small influence on the system operation and the like, is simple to operate and is easy to realize.

Description

technical field [0001] The invention relates to a measurement and control method of electrical technology, in particular to a comprehensive control technology for tuning of a resonant grounding system and limiting neutral point displacement voltage. Background technique [0002] When a single-phase ground fault occurs in the power grid, the arc suppression coil can generate an inductive current at the neutral point to compensate the ground capacitance current, greatly reducing the fault current and achieving the effect of arc extinguishing. my country's distribution network is mostly grounded by arc suppression coils. When the arc suppression coil is fully compensated, it is easy to cause resonance overvoltage, and the voltage displacement of the neutral point for a long time should not exceed 15% of the system phase voltage. [0003] At present, among the capacitive current measurement methods proposed, the extreme value method, the phase method, and the impedance triangle ...

AI Technical Summary

Problems solved by technology

When the arc suppression coil is fully compensated, it is easy to cause resonance overvoltage, and the voltage displacement of the neutral point for a long time should not exceed 15% of the phase voltage of the system

[0003] At present, among the capacitive current measurement methods proposed, the extreme value method, the phase method, and the impedance triangle method are only applicable to the pre-adjusted arc suppressing coil, which belongs to the indirect step-by-step measurement, and cannot measure the distributed conductance of the system to the ground, and the measurement process is cumbersome. Only applicable to pre-adjusted arc suppressing coils; two-point method, three-point method, injection signal method, resonance method combined with curve fitting method and known incremental compensation current method can directly measure the capacitive current when the fault is grounded, although it is suitable for pre-adjustment The adjustable mode is also suitable for the adjustable arc suppressing coil, but it is theoretically impossible or impossible to realize the complete and accurate measurement of the system capacitance and conductance or the measurement control method is complicated

Adjustable arc suppressing coils often take the way of overcompensating 15% to keep away from the resonance point to limit the neutral point displacement voltage; pre-adjusted arc suppressing coils are multi-parallel damping resistors to limit the neutral point displacement voltage, but the above method cannot accurately The neutral point displacement voltage is controlled at a certain target value

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