Overcurrent fault monitoring protection device and method for flexible direct-current transmission inverter station

Abstract

The invention provides an overcurrent fault monitoring protection device and method for a flexible direct-current transmission inverter station and relates to the technical field of power system control. The device comprises a microprocessor unit, a composite buffer protection unit, a power frequency conversion unit, an IGBT drive unit, an overheating detection unit, a fault current detection unit, a wireless communication unit, an LC filter and an upper computer, wherein a microprocessor processes the current and temperature information acquired by the overheating detection unit and the fault current detection unit, drives the IGBT drive unit to control the on / off of the IGBT device and transmits the fault information to the upper computer. In the invention, the type of the fault current and the overheating fault of the power frequency conversion unit can be detected and positioned, the detected fault current is positioned, classified and processed so as to quickly and accurately inhibit the short-circuit current and overcurrent in the fault period, the damage of the power frequency conversion unit is avoided, and the monitoring position and protection of overcurrent fault of the flexible direct-current transmission inverter station are realized.

Description

technical field [0001] The invention relates to the technical field of power system control, in particular to an overcurrent fault monitoring and protection device and method for a flexible direct current transmission inverter station. Background technique [0002] With the prominence of environmental problems and the intensification of the energy crisis, renewable energy such as wind energy and solar energy has developed by leaps and bounds. As an effective way to connect clean energy to the grid, flexible DC transmission technology has attracted more and more attention. Due to the adjustment method of the flexible DC transmission system and the inherent characteristics of its own structure, the fault current of the DC transmission line has the characteristics of fast rising speed and large peak value, and frequent overcurrent faults. When a fault occurs, the fault current can easily damage the converter of the inverter station. The current equipment and equipment are insu...

AI Technical Summary

Problems solved by technology

Due to the adjustment method of the flexible DC transmission system and the inherent characteristics of its own structure, the fault current of the DC transmission line has the characteristics of fast rising speed and large peak value, and frequent overcurrent faults. When a fault occurs, the fault current can easily damage the converter of the inverter station. The current equipment and equipment are insulated, and the flexible DC transmission cannot monitor, locate and classify the fault current through relevant measures, and cannot realize the self-clearing of the fault by adjusting the trigger angle. high demands

At present, the protection of DC lines in flexible DC transmission projects only draws on the protection strategy of traditional HVDC transmission, which does not meet the requirements of fast action of flexible DC line protection.

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