Stability discrimination device for direct-driven wind power plant through LCC-HVDC output system

Abstract

The invention provides a stability discrimination device for a direct-driven wind power plant through an LCC-HVDC output system, which can accurately obtain the system impedance, effectively evaluate the stability margin of the system and accurately judge whether the direct-driven wind power plant through the LCC-HVDC output system is stable in oscillation or not. Positive sequence impedance and coupling impedance of a direct-driven wind power plant through an LCC-HVDC output system in a full frequency band are accurately obtained through the device, equivalent impedance of the system under the impedance action of a power grid is calculated by considering the machine-network coupling effect, the system stability is analyzed more accurately and effectively, then the system stability is judged by using the maximum peak criterion, the criterion representation form is more concise, the flexibility and accuracy of the criterion are further improved, the defect that the stability evaluation of the direct-driven wind power plant through the LCC through the HVDC sending-out system is inconvenient and inaccurate in the current research is overcome, and an important basis is provided for the design and grid connection of the direct-driven wind power plant through the LCC through the HVDC sending-out system.

Description

technical field [0001] The invention belongs to the technical field of direct-current high-voltage power transmission systems, and in particular relates to a stability judging device for a direct-drive wind farm sending out a system through an LCC-HVDC. Background technique [0002] In recent years, the installed capacity of direct-drive wind turbines in my country has increased year by year. However, the reverse and unbalanced nature of my country's electric energy demand and resource distribution in time and space predestined that my country's development and utilization of wind power must follow the centralized distribution of wind power from remote areas with abundant wind energy resources (such as Hami, Jiuquan, Mengdong, etc.). The way to realize the consumption of long-distance load centers such as "Sanhua area". The traditional LCC-HVDC power transmission technology occupies a dominant position in the current and future HVDC construction due to its large-capacity pow...

AI Technical Summary

Problems solved by technology

However, at present, no effective evaluation scheme has been proposed for the stability judgment of the AC-DC interconnection and multi-port direct-drive wind farm transmission system via LCC-HVDC. Therefore, it is urgent to break through the multi-port system stability judgment considering the frequency coupling effect Difficult problem, analyze the stability of the direct drive wind farm sending system via LCC-HVDC

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