A compound grounding device based on active inverter voltage regulation and small resistance

Abstract

The invention discloses a composite grounding device based on active inverter voltage regulation and small resistance, which includes a high-resistance ground fault identification unit, an active inverter voltage regulator, a small resistance zero-sequence protection device and a coordination controller; The high-impedance ground fault identification unit is used to accurately identify the fault feeder; the active inverter voltage regulator receives the operation command issued by the coordination controller, and injects the adjusted voltage into the neutral point; the small resistance zero-sequence protection device is used Ground fault processing when the fault current is not lower than the zero-sequence protection threshold; the coordination controller is responsible for the coordination and cooperation between the active inverter voltage regulator and the small-resistance zero-sequence protection device. The present invention can efficiently suppress the fault point voltage through the efficient coordination and cooperation of the active inverter voltage regulator and the small resistance zero-sequence protection device, and realize efficient and reliable processing of transient and permanent grounding faults, especially for high-resistance The suppression of ground fault has very good feasibility and practical value.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a composite grounding device based on active inverter voltage regulation and small resistance. Background technique [0002] The distribution network is located at the end of the power system and is closely related to users. Therefore, how to improve the safety and reliability of the distribution network in the event of a fault has always been a research hotspot. The resonant grounding system represented by the arc suppression coil is widely used in urban and rural distribution networks because of its simple working principle and ability to maintain the normal operation of faulted feeders under instantaneous ground faults. However, with the continuous development of urban distribution network, the continuous increase of cable lines and nonlinear loads leads to the increasing amplitude of ground fault current. Traditional arc suppression coils are difficult to expand, ...

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Problems solved by technology

[0005] In order to solve the deficiencies mentioned in the above-mentioned background technology, the object of the present invention is to provide a composite grounding device based on active inverter voltage regulation and small resistance, inject the regulated voltage to the neutral point through the active inverter voltage regulator, It can efficiently suppress the fault point voltage and realize fault elimination. Through the efficient coordination and cooperation of the source inverter voltage regulator and the small resistance zero-sequence protection device, it can realize efficient and reliable processing of instantaneous ground faults and permanent ground faults, and solve the problem of High-impedance ground fault identification and suppression are difficult problems

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