Discrimination Method for Voltage Stability of DC Receiver AC System Based on WAMs Dynamic Tracking

Abstract

The invention discloses a voltage stability discrimination method for a DC receiving end AC system based on WAMS (Wide Area Measurement System) dynamic tracking. The method is characterized by comprising the following steps of: calculating the voltage stability level of a receiving system of an AC system in the normal operation mode of the AC system; calculating the voltage stability level of the receiving system of the AC system under the line fault disconnection condition; sorting line faults; combining a worst cascading fault set; calculating the voltage stability level of the receiving end AC system under the cascading fault condition; and judging whether the voltage instability occurs or not. The voltage stability discrimination method provided by the invention has the advantages of performing the characteristic analysis of the transient voltage instability accidents existing in existing and planned AC / DC hybrid power grids, providing effective fault screening and sorting according to the degree of damage caused by the AC fault to the stable operation of the DC system, reasonably establishing the cascading fault set by combining a power flow transferring condition after faults, and quickly assessing the grid voltage instability risk of the receiving end of the DC system after faults.

Description

technical field [0001] The invention relates to a method for judging voltage stability of a DC receiving end AC system based on WAMS dynamic tracking, and belongs to the technical field of power system safety and stability analysis. Background technique [0002] At present, my country's power grid has formed an UHV AC-DC interconnected grid, which is connected to multiple large-scale AC grids through a DC system. According to the trend, my country will also build dozens of UHV DC projects in the next 10-20 years, and gradually form a UHV AC-DC hybrid power grid to supply power to the load center through UHV DC and AC systems. Conventional HVDC power transmission systems require the AC system at the receiving end to provide sufficient commutation voltage, and will absorb a large amount of reactive power from the AC system after commutation failure occurs. Security and stability problems caused by power reserve problems. [0003] With the rapid development of dispatching con...

AI Technical Summary

Problems solved by technology

The current research methods for this problem are still single. In engineering, the time domain simulation method is mainly used. Through the transient stability simulation of various AC and DC system fault combinations, it is evaluated whether it will cause the continuous commutation failure of the DC system, and then cause more damage. It is a serious cascading failure; however, this method faces problems such as heavy workload and difficulty in enumerating potential failures

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