Pole placement under a passivity constraint for the AC current control of a modular multilevel converter

Thomas F, Fischer F, Lorenz A, Graichen K (2026)

Publication Type: Journal article

Publication year: 2026

Journal

IEEE Access Institute of Electrical and Electronics Engineers (IEEE)

Book Volume: 14

Pages Range: 110496-110513

DOI: 10.1109/ACCESS.2026.3714899

Abstract

With the growing importance of voltage source converters in the electrical power grid, ensuring their reliability by fulfilling performance requirements is becoming increasingly important. At the same time, the passivity of the converter input admittance is crucial to ensure the stability of the interaction with the AC grid. Fulfilling all requirements at the same time renders the design of the AC current control (ACCC) a challenging task. This paper proposes a pole placement method that incorporates an explicit passivity constraint for the ACCC of modular multilevel converters in HVDC applications. Based on a simplified analytical model, the design parameters are derived directly from the performance specifications. Subsequently, the remaining degrees of freedom are utilized to fulfill the passivity requirement, making the underlying constraints and trade-offs transparent. The method is validated through MATLAB simulations using a representative design example. A comparison with an H∞ -based optimization method from the literature demonstrates that the proposed approach yields competitive performance with a lower control order. Finally, a robustness analysis is conducted to assess the effect of previously neglected model dynamics and the grid model. The results show that delays in the automation interface have a small impact on all objectives except passivity, whose sensitivity depends mainly on the delay magnitude and the desired tracking speed.

Authors with CRIS profile

Fynn Thomas Chair of Automatic Control (LRT/AC) Knut Graichen Chair of Automatic Control (LRT/AC)

Related research project(s)

Robust energy-based control of MMC/HVDC systems June 15, 2023 - Dec. 31, 2026

Involved external institutions

Siemens Energy (Germany) DE Germany (DE)

How to cite

APA:

Thomas, F., Fischer, F., Lorenz, A., & Graichen, K. (2026). Pole placement under a passivity constraint for the AC current control of a modular multilevel converter. IEEE Access, 14, 110496-110513. https://doi.org/10.1109/ACCESS.2026.3714899

MLA:

Thomas, Fynn, et al. "Pole placement under a passivity constraint for the AC current control of a modular multilevel converter." IEEE Access 14 (2026): 110496-110513.

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