A voltage source type energy storage wide frequency band negative resistance characteristic analysis method based on impedance splitting

By simplifying the impedance model of voltage source energy storage inverters through impedance decomposition, dividing the frequency band and analyzing the negative resistance characteristics of the mid-frequency band, the instability problem of voltage source energy storage systems in inductive weak power grids is solved, thereby improving system stability.

CN116577559BActive Publication Date: 2026-05-29NORTHWEST BRANCH OF STATE GRID POWER GRID CO +1
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Patent Information

Application Number
CN202310465947.9
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2023-04-26
Publication Date
2026-05-29
Estimated Expiration
2043-04-26

AI Technical Summary

Technical Problem

Existing technologies cannot accurately pinpoint the source of negative damping generated by voltage source type energy storage inverters in long-distance, weakly inductive grid environments, leading to system instability and failing to effectively improve system stability.

Method used

An impedance-based approach is adopted to simplify the impedance model of a voltage source energy storage grid-connected inverter system through a complex vector synchronization link, dividing it into low-frequency, medium-frequency, and high-frequency bands. The source of negative resistance in the medium-frequency band is analyzed, and the negative resistance characteristics are accurately located using the impedance-based approach.

Benefits of technology

It enables precise analysis and risk identification of frequency band stability in voltage source energy storage systems, provides a reference for improving the small-signal stability of the system, and avoids the risk of system instability.

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Abstract

The application discloses a voltage source type energy storage wide frequency band negative resistance characteristic analysis method based on impedance splitting. The method is simplified based on a voltage source type energy storage impedance model, impedance characteristics of a simplified model in a wide frequency band range are analyzed, impedance frequency bands are divided according to characteristics of a voltage source type energy storage controller and the wide frequency band impedance characteristics, a medium frequency band negative resistance source is analyzed by using the impedance splitting method, and the voltage source type energy storage instability risk positioning method is improved, thereby providing a reference for improving small signal stability of the voltage source type energy storage.
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Citation Information

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