A dynamic virtual impedance control method for multi-machine parallel connection of network-constructed energy storage converters

CN121643012BActive Publication Date: 2026-05-29이너 몽골리아 일렉트릭 파워 그룹 컴퍼니 리미티드 이너 몽골리아 일렉트릭 파워 리서치 인스티튜트 브랜치
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
이너 몽골리아 일렉트릭 파워 그룹 컴퍼니 리미티드 이너 몽골리아 일렉트릭 파워 리서치 인스티튜트 브랜치
Filing Date
2026-02-04
Publication Date
2026-05-29

AI Technical Summary

Technical Problem

Existing fixed-parameter virtual impedance control strategies struggle to simultaneously achieve precise reactive power allocation, effective circulating current suppression, dynamic response speed, and voltage regulation accuracy in multi-machine parallel systems, especially exhibiting drastic fluctuations in control performance under time-varying line parameters.

Method used

The dynamic virtual impedance control method is adopted. By introducing a dynamically adjustable virtual impedance module at the voltage outer loop control command output of each converter, and combining the locally measured output current, bus voltage amplitude and its rate of change and the system average reactive power, a dynamic virtual impedance is generated in real time, which includes dynamic virtual resistance and inductance components. This is used to correct the voltage command and achieve adaptive compensation.

Benefits of technology

Under scenarios such as sudden load changes, asymmetrical line parameters, and communication interruptions, the system achieves reactive power distribution error of less than 5%, high-frequency circulating current suppression of less than 5% of rated current, and bus voltage drop of less than 3%, significantly improving the system's dynamic response speed and voltage regulation accuracy, and adapting to changes in line parameters.

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Patent Text Reader

Abstract

The application discloses a kind of dynamic virtual impedance control methods of network type energy storage converter multi-machine parallel, belong to the field of power electronics.The method aims at solving the problem that fixed parameter virtual impedance is difficult to consider reactive power accurate distribution, circulating current suppression, dynamic response and voltage accuracy in multi-machine parallel system.Dynamic adjustable virtual impedance module is introduced in the voltage outer loop output end of each converter, based on the output current, bus voltage rate of change and adjacent machine reactive deviation information measured locally, real-time calculation virtual resistance and virtual inductance;And through phase synchronization mechanism, the average reactive power of system is estimated under the condition of no communication to realize multi-machine cooperation.The method realizes that reactive power distribution error is less than 5%, bus voltage drop is lower than 3%, high-frequency circulating current control is within 5% of rated current under all operating conditions, which significantly improves the dynamic performance and robustness of the system.
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