Absorption type grounding circuit and method for reducing grounding impedance

Abstract

The invention discloses an absorption type grounding circuit and method for reducing grounding impedance. The circuit comprises a grounding grid and a capacitance absorption apparatus. Two ends of the capacitance absorption apparatus are respectively in connection with the grounding grid and a zero potential earth pole. In the method, the capacitance absorption apparatus is in series connection between the grounding grid and the zero potential earth pole. The circuit can improve path conditions of transformer station grounding grid discharge over the ground, absorb shock wave wavefront and reduce grounding impedance, and has the characteristics of excellent grounding effect, low ground potential, convenient installation, reliable operation and low manufacturing cost.

Description

technical field [0001] The invention relates to grounding technology, in particular to an absorbing grounding circuit and method capable of reducing grounding impedance. Background technique [0002] The electrical facilities of substations should be struck by lightning, and most of them are located in areas with high soil resistivity. The counterattack of the ground potential and the transient voltage increase of the tower seriously affect the safe operation of the power supply system. [0003] Traditional grounding is laid in the ground with metal materials, which are called grounding wires or grounding grids. For nearly a century, human beings have guided and developed grounding technology on the basis of Ohm's law and the concept of voltage and current in a linear state. And to pursue a lower grounding resistance as the goal. However, in the process of pursuing a lower grounding resistance, a large number of reports from home and abroad show that a grounding system with...

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Problems solved by technology

However, in the process of pursuing a lower grounding resistance, a large number of reports from home and abroad show that a grounding system with a lower grounding resistance is not the most suitable grounding system, and the characteristics of the grounding device under the action of the impulse current and the power frequency current There is a big difference in the action, due to the influence of the inductive component of the grounding device itself, it shows obvious nonlinear time-varying characteristics

[0004] For large-scale grounding grids, its inductive component cannot be ignored. Under the action of lightning current with high-frequency components and other impact currents, the inductance effect of the substation grounding grid is obvious, and even plays a major role. The lightning current cannot be safely and effectively released, resulting in The transient potential of the high-voltage power transmission and transformation system rises and superimposes with the counter voltage of the ground potential, which has a more serious impact on the safe operation of the power supply system

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