Active Arc Suppression Method for Distribution Network Ground Fault without Power Supply on DC Side of Converter

Abstract

The present invention proposes an active arc suppression method for distribution network grounding faults without power supply on the DC side of the converter. The grid-connected arc suppression device is pre-charged to make its DC side capacitor voltage reach the target value; after a single-phase ground fault occurs, the current is injected into the distribution network through the arc suppression device to realize full compensation of the single-phase ground fault current, and to ensure that the arc suppression process The DC side voltage of the medium device is constant. During the arc suppression process, the arc suppression device used in the present invention does not need to switch the switch to realize the selection of grid-connected phase lines, and can inject arc suppression current from any two phases of the distribution network to realize full compensation of single-phase grounding fault current, effectively reducing the The number of components reduces the requirements for the installation conditions of the arc suppression device and simplifies the arc suppression process.

Description

technical field [0001] The invention belongs to the technical field of power electronic equipment control, and in particular relates to an active arc suppression method for a grounding fault of a distribution network without a power supply at the DC side of a converter. Background technique [0002] In recent years, with the continuous expansion of the distribution network scale, the probability of single-phase ground faults has increased significantly, accounting for more than 80% of the total distribution network faults. Arcing ground faults caused by single-phase ground faults will pose a serious threat to the safe operation of the distribution network and the lives and properties of surrounding personnel. In order to solve the problem of ground fault arc suppression in distribution network, passive arc suppression technology and active arc suppression technology are widely used. Among them, active arc suppression technology is expected to gradually replace passive arc s...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, some active arc suppression devices use a three-phase cascaded H bridge as the main circuit, which can be directly connected to the three phase lines of the distribution network. The number of components required by the device is large and the withstand voltage requirement is high; some The active arc suppression device uses a single H-bridge inverter with a step-up transformer or a single-phase cascaded H-bridge as the main circuit, and is connected to the distribution network through a grounding transformer. Although it can reduce the required components and reduce the requirements for withstand voltage, However, the additional transformer further expands the footprint of the device

Moreover, when the above-mentioned active arc suppression device is used to fully compensate the single-phase ground fault current, there is a problem that it is difficult to obtain the source of the DC side capacitance of the device.

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