Automatic tuning method of preset arc suppression coil

Abstract

The invention relates to an automatic tuning method of a preset arc suppression coil, which comprises the following steps: further calculating the off tuning degree and the damping ratio of a power grid through measuring the change on the unbalanced voltage of the power grid; measuring the unbalanced voltage at the neutral point of the power grid and a certain line voltage value of the power grid during the normal operation of the power grid, calculating and monitoring the change on the relative unbalance degree of the power grid to judge whether the off tuning degree of the power grid is changed, i.e. whether the power grid requires line delivering and switching operations, and deciding whether the off tuning degree and the damping ratio of the power grid are newly measured; when the off tuning degree and the damping ratio of the power grid are measured, firstly measuring the unbalanced voltages of the power grid, then, controlling a tuned arc suppression coil to increase and output compensating current (electrical susceptance) for the power grid by a controller, and finally, measuring the unbalanced voltage of the power grid and calculating the off tuning current and the damping ratio of the power grid. The arc suppression coil is adjusted according to the measured off tuning current of the power grid to output the compensating current and then the currently running off tuning current of the power grid is further calculated again so as to validate that the currently running tuning current of the power grid is smaller than the setting valve of the off tuning current.

Description

technical field [0001] The invention relates to a measurement and control method in the field of electrical technology, in particular to an automatic tracking and tuning control technology for a power grid neutral point grounding system via an arc suppression coil. Background technique [0002] When a single-phase ground fault occurs in the resonant grounding system, the smaller the residual current at the ground fault point, the more conducive to the extinguishment of the fault arc, the more conducive to fault self-recovery, and the more conducive to improving the reliability of the power supply of the distribution network. Therefore, arc suppression is required The coil tuning controller can measure the grid grounding capacitor current with as high accuracy as possible, so that the arc suppressing coil can operate as close to the "full compensation" state as possible. There are measurement methods for automatic tracking and tuning control of pre-adjusted arc suppression co...

AI Technical Summary

Problems solved by technology

There are measurement methods for automatic tracking and tuning control of pre-adjusted arc suppression coils, such as zero sequence voltage maximum value method, impedance triangle method, phase tuning method, etc., which have their own characteristics and are suitable for arc suppression coils with different inductance adjustment methods, but They have a common defect, that is, they do not accurately measure the ground capacitance current of the power grid, but gradually approach the "full compensation" state. Therefore, the tuning control cannot be in place at one time, which will increase the mechanical adjustment method of the arc suppression coil (such as: tuning) air gap type, turn-tuning type) measurement and control system failure rate, shorten the life of the measurement and control system, and these tuning methods reflect low speed and low adjustment accuracy

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