Automatic tuning control method of post-set arc suppression coils

Abstract

The invention discloses an automatic tuning control method of post-set arc suppression coils, which works out the active component in network earth capacitive current and network grounded fault current by measuring variation of unbalanced voltage of a network. During normal operation of the network, the neutral point unbalanced voltage of the network and a thread of voltage value of the network are measured, the variation of relative unbalanced degree of the network is calculated and monitored so as to determine whether compensation operation exists in the network or not and to determine whether the active component in the network earth capacitive current and the network grounded fault current is remeasured or not. Measuring the active component in the network earth capacitive current and the network grounded fault current comprises the following steps: firstly measuring the unbalanced voltage of the network, then controlling the post-set arc suppression coil to increase to output a compensation current (susceptance) by a controller, and measuring the unbalanced voltage of the network again so as to calculate the active component in the network earth capacitive current and the network grounded fault current. The invention is simple and easy to operate without affecting the normal operation of the network, has high measuring precision and is particularly suitable for post-set control of arc suppression coils.

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 a 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. In the resonant grounding system, the residual current at the ground fault point mainly has two parts: one is the reactive zero-sequence current after under-compensation or over-compensation, and its magnitude depends on the compensation detuning degree. The automatic tracking compensation technology of the arc suppression coil can ensure that the current ...

AI Technical Summary

Problems solved by technology

The second is the active power loss current of the zero-sequence circuit of the power grid

There are a variety of automatic tracking and tuning control methods for arc-suppression coils with adjustment, and the two-point analysis method [1] , Injection frequency conversion signal method [2-3] , inject power frequency current [4] , resonance method combined with curve fitting method [5] etc. After they measure the ground capacitance current of the power grid online, they control the automatic tuning of the arc suppression coil, which effectively suppresses the size of the first part of the residual current, and have been used in the stand-alone tuning control of the arc suppression coil of the distribution network in my country, while the second The on-line accurate measurement of partial residual current (active component of ground current) is rarely known, and there is no more mature and more accurate measurement method

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