Method for continuously tracking and measuring grounding current of automatic compensating device of arc suppression coil

Abstract

The invention relates to a method for continuously tracking and measuring a grounding current of an automatic compensating device of an arc suppression coil. The method is suitable for a pure cable power network or a cable aerial wire hybrid power network which has low degree of natural asymmetry. The method can continuously track and measure a capacitive current (compensating current) component and active current (damping current) component of the single-phase grounding current of the power network by monitoring the amplitude and the phase of zero sequence voltage of the power network. Theoretically, the measurement error of the method is not greater than Deltav= (delt Iv) / Iv<=U*00 / (U*0-U*00). The method is simple and easy to implement. Only the detection of one electric quantity parameter can lead to the continuous tracking and monitoring of two parameters needed by an automatic tracking compensating controller of the arc suppression coil. The method can be easily realized by using a single chip microcontroller, without any operation to the arc suppression coil or influencing the normal work of the power network. The method is applicable to the tuning control of not only a post-set arc suppression coil but also a preset arc suppression coil, and is a general measurement method for the grounding current of the automatic compensating device of the arc suppression coil.

Description

technical field [0001] The invention relates to a measurement method in the field of electrical technology, in particular to an automatic tracking and measurement technology for distribution network grounding current used for arc suppression coil control. Background technique [0002] There are many tuning control methods for arc suppression coils: displacement voltage maximum value method, impedance triangle method, phase tuning method, two-point analysis method, resonance method combined with curve fitting method, etc., each of which has its own characteristics. Such as: displacement voltage maximum value method, impedance triangle method, and phase tuning method, the arc suppression coil needs to be continuously adjusted during tuning, which will greatly shorten the life of the mechanical components (such as on-load switches) used for gear adjustment, and it is only applicable to " Pre-tuning" arc suppressing coils cannot give the value of detuning current or capacitive c...

AI Technical Summary

Problems solved by technology

Such as: displacement voltage maximum value method, impedance triangle method, and phase tuning method, the arc suppression coil needs to be continuously adjusted during tuning, which will greatly shorten the life of the mechanical components (such as on-load switches) used for gear adjustment, and it is only applicable to " Pre-tuning" arc suppressing coils cannot give the value of detuning current or capacitive current; two-point analysis method, resonance method combined with curve fitting method can directly measure the grounding capacitive current of the power grid, so it can be applied to "follow tuning", It is also applicable to the control of "pre-tuning" arc suppressing coil, but the arc suppressing coil is also required to be operated multiple times during tuning, which will also shorten the life of the mechanical components used for gear shifting, and cannot continuously control the detuning current or capacitive current of the grid Therefore, the tuning and measuring device needs to have a correct judgment on the change of the grid zero-sequence parameter (line operation) in order to re-measure; the above tuning and measuring method is suitable for overhead with a high degree of natural asymmetry (above 0.5%) Wire or overhead wire and cable hybrid grid, while the pure cable grid (such as coal mine) has a low natural asymmetry, generally below 0.5%, and some coal mine grids are only 0.02%

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