Method, device and equipment for evaluating short-circuit ratio of high-voltage direct-current power transmission system and medium

Abstract

The invention discloses a method for evaluating the short-circuit ratio of a high-voltage direct-current power transmission system. The method comprises the steps: obtaining the voltage values of an alternating-current three-phase bus before and after switching when the switching state of an alternating-current filter of a converter station is detected to be changed; according to the voltage values of the AC three-phase bus, calculating an AC bus voltage change rate before and after switching; calculating a converter bus short-circuit ratio according to the rated capacity of an converter station AC filter bank and the rated transmission capacity of a high-voltage DC power transmission system; acquiring a DC power value transmitted by the high-voltage DC power transmission system and group number information of thealternating-current filter of the converter station in operation in real time; calculating the effective short-circuit ratio of the converter bus; and evaluating the converter bus short-circuit ratio and the converter bus effective short-circuit ratio to obtain the system strength of the AC system connected with the high-voltage DC power transmission system. The problem of parameter drift can be effectively solved, and the accuracy of calculating the short-circuit ratio is improved. The invention further discloses a device and equipment for evaluating the short-circuit ratio of the high-voltage direct-current power transmission system and a medium.

Description

technical field [0001] The invention relates to the technical field of high-voltage direct current transmission systems, in particular to an evaluation method, device, equipment and medium for short-circuit ratios of high-voltage direct current transmission systems. Background technique [0002] my country's coal resources are mainly distributed in the western and northern regions, hydropower resources are mainly concentrated in the southwest region, and the primary energy resources in the eastern region are scarce and the electricity load is relatively concentrated. The unbalanced distribution of energy resources and power load determines the necessity of power transmission from west to east. Due to the long transmission distance and large capacity, the advantages of HV / UHV DC transmission technology have been developed rapidly. [0003] The operation of the HVDC transmission system requires the support of the commutation voltage provided by the AC system. The safe and sta...

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Problems solved by technology

[0003] The operation of the HVDC transmission system requires the support of the commutation voltage provided by the AC system. The safe and stable operation of the system depends on the strength of the AC system. There are related problems in the operation of the HVDC system connected to the weak AC system: high dynamic overvoltage, voltage instability , Harmonic resonance and harmonic instability, fault recovery and transient instability, etc., seriously affect the normal operation of the system

At present, in the research on online calculation of short-circuit ratio and effective short-circuit ratio, there is the problem of drift of Thevenin equivalent parameters, and it is impossible to accurately calculate real-time short-circuit ratio

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