A Method for Discriminating Voltage Stability of DC Receiver AC System Based on WAMs Abnormal Fluctuation Dynamic Tracking

Abstract

The invention discloses a method for judging the voltage stability of a DC receiving-end AC system based on WAMS abnormal fluctuation dynamic tracking, including: 1. Extracting the voltage fluctuation waveform of the recent abnormal fluctuation information for statistics, and determining the operation mode in which voltage jitter often occurs; 2. Collect samples of fluctuation data, whose attributes are characteristic attributes under different operating modes; 3. Cluster the collected information pairs: attribute 2-dominant frequency damping ratio, attribute 6-voltage abnormal fluctuation level coefficient; 4. Adaptability The sample point with the highest information is taken as the first cluster center; 5. Correct the sample point for the above information; 6. Determine all the cluster center points and the number of clusters H, and combine the analysis of the power flow situation and the power-on situation to form The criterion of the voltage stability level is simplified to realize the judgment of the voltage stability of the AC system at the receiving end of the DC. The invention has a small amount of calculation, is easy to be implemented on-line, and can realize rapid judgment of the voltage instability problem of a DC receiving terminal and reasonable construction of a cascading fault set.

Description

technical field [0001] The invention belongs to the technical field of power system safety and stability analysis, and in particular relates to a method for judging voltage stability of an AC system at a DC receiving end based on dynamic tracking of WAMS abnormal fluctuations. Background technique [0002] At present, China's power grid has formed an UHV AC interconnected grid, which is connected to major 500 kV AC grids through a high-voltage DC system. According to the trend, China will build dozens of UHV DC projects in the next 10-20 years, and gradually form a UHV AC-DC hybrid power grid, which will supply power to the central and eastern load centers through UHV DC and AC systems. Conventional HVDC transmission systems require sufficient commutation voltage from the AC system at the receiving end, and will absorb a large amount of reactive power from the AC system after commutation failure occurs. After multiple DC feeds, the receiving end grid will face serious securi...

AI Technical Summary

Problems solved by technology

[0004] For the AC / DC hybrid fed into the receiving end power grid, the more serious safety and stability problem is: the possible cascading faults of the AC / DC system, that is, the failure of the AC system may cause the DC system to continue to fail in phase commutation, which in turn leads to DC blocking with higher power Transferred to the AC channel, triggering a cascading grid collapse accident

However, the current research focuses on theoretical analysis or summary of operating experience, and how to propose an effective and practical method for the construction of cascading fault sets combined with the actual situation of the power grid still needs further development

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