Flexible Synchronization Control for Grid-Forming Converters with Regulated DC-Link Dynamics

Liang Zhao; Xiongfei Wang; Zheming Jin

doi:10.1109/ECCE50734.2022.9947855

Flexible Synchronization Control for Grid-Forming Converters with Regulated DC-Link Dynamics

Liang Zhao, Xiongfei Wang, Zheming Jin

Research output: Contribution to book/anthology/report/conference proceeding › Article in proceeding › Research › peer-review

Abstract

In grid-forming (GFM) converters with regulated dc-link dynamics, the dc-link voltage control can directly generate the frequency that is used for synchronizing GFM converters with the grid. However, this synchronization method suffers from low-frequency oscillations (LFO). To tackle this challenge, this paper proposes a flexible synchronization control scheme for grid-forming converters. In the approach, the dc-link voltage control, the active power feedforward control, and the q-axis voltage feedforward control loops are connected in parallel for the synchronization purpose. It is found that both the active power feedforward and the q-axis voltage feedforward loops can dampen the LFO. Yet, the active power feedforward loop with different controllers induces additional synchronous- or low-frequency instability issues, whereas the q-axis voltage feedforward loop does not have such adverse effect. Therefore, the paralleled dc-link voltage and q-axis voltage feedforward control-based synchronization scheme is recommended. Experimental tests of GFM converters with different grid impedances are performed. The results confirm the effectiveness of theoretical analysis and of the proposed control approach.

Original language	English
Title of host publication	2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022
Publisher	IEEE
Publication date	2022
ISBN (Electronic)	9781728193878
DOIs	https://doi.org/10.1109/ECCE50734.2022.9947855
Publication status	Published - 2022
Event	2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022 - Detroit, United States Duration: 9 Oct 2022 → 13 Oct 2022

Conference

Conference	2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022
Country/Territory	United States
City	Detroit
Period	09/10/2022 → 13/10/2022

Series	IEEE Energy Conversion Congress and Exposition
ISSN	2329-3721

Bibliographical note

Publisher Copyright:
© 2022 IEEE.

Keywords

constant-power dynamics
dc-link voltage control
Grid-forming control
low-frequency oscillation
synchronous resonance

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10.1109/ECCE50734.2022.9947855

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Cite this

@inproceedings{df2e4e163c90476e8d5cb96a174a0eec,

title = "Flexible Synchronization Control for Grid-Forming Converters with Regulated DC-Link Dynamics",

abstract = "In grid-forming (GFM) converters with regulated dc-link dynamics, the dc-link voltage control can directly generate the frequency that is used for synchronizing GFM converters with the grid. However, this synchronization method suffers from low-frequency oscillations (LFO). To tackle this challenge, this paper proposes a flexible synchronization control scheme for grid-forming converters. In the approach, the dc-link voltage control, the active power feedforward control, and the q-axis voltage feedforward control loops are connected in parallel for the synchronization purpose. It is found that both the active power feedforward and the q-axis voltage feedforward loops can dampen the LFO. Yet, the active power feedforward loop with different controllers induces additional synchronous- or low-frequency instability issues, whereas the q-axis voltage feedforward loop does not have such adverse effect. Therefore, the paralleled dc-link voltage and q-axis voltage feedforward control-based synchronization scheme is recommended. Experimental tests of GFM converters with different grid impedances are performed. The results confirm the effectiveness of theoretical analysis and of the proposed control approach.",

keywords = "constant-power dynamics, dc-link voltage control, Grid-forming control, low-frequency oscillation, synchronous resonance",

author = "Liang Zhao and Xiongfei Wang and Zheming Jin",

note = "Publisher Copyright: {\textcopyright} 2022 IEEE.; 2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022 ; Conference date: 09-10-2022 Through 13-10-2022",

year = "2022",

doi = "10.1109/ECCE50734.2022.9947855",

language = "English",

series = "IEEE Energy Conversion Congress and Exposition",

booktitle = "2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022",

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}

Zhao, L, Wang, X & Jin, Z 2022, Flexible Synchronization Control for Grid-Forming Converters with Regulated DC-Link Dynamics. in 2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022. IEEE, IEEE Energy Conversion Congress and Exposition, 2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022, Detroit, United States, 09/10/2022. https://doi.org/10.1109/ECCE50734.2022.9947855

Flexible Synchronization Control for Grid-Forming Converters with Regulated DC-Link Dynamics. / Zhao, Liang; Wang, Xiongfei; Jin, Zheming.
2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022. IEEE, 2022. (IEEE Energy Conversion Congress and Exposition).

Research output: Contribution to book/anthology/report/conference proceeding › Article in proceeding › Research › peer-review

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AU - Wang, Xiongfei

AU - Jin, Zheming

PY - 2022

Y1 - 2022

N2 - In grid-forming (GFM) converters with regulated dc-link dynamics, the dc-link voltage control can directly generate the frequency that is used for synchronizing GFM converters with the grid. However, this synchronization method suffers from low-frequency oscillations (LFO). To tackle this challenge, this paper proposes a flexible synchronization control scheme for grid-forming converters. In the approach, the dc-link voltage control, the active power feedforward control, and the q-axis voltage feedforward control loops are connected in parallel for the synchronization purpose. It is found that both the active power feedforward and the q-axis voltage feedforward loops can dampen the LFO. Yet, the active power feedforward loop with different controllers induces additional synchronous- or low-frequency instability issues, whereas the q-axis voltage feedforward loop does not have such adverse effect. Therefore, the paralleled dc-link voltage and q-axis voltage feedforward control-based synchronization scheme is recommended. Experimental tests of GFM converters with different grid impedances are performed. The results confirm the effectiveness of theoretical analysis and of the proposed control approach.

AB - In grid-forming (GFM) converters with regulated dc-link dynamics, the dc-link voltage control can directly generate the frequency that is used for synchronizing GFM converters with the grid. However, this synchronization method suffers from low-frequency oscillations (LFO). To tackle this challenge, this paper proposes a flexible synchronization control scheme for grid-forming converters. In the approach, the dc-link voltage control, the active power feedforward control, and the q-axis voltage feedforward control loops are connected in parallel for the synchronization purpose. It is found that both the active power feedforward and the q-axis voltage feedforward loops can dampen the LFO. Yet, the active power feedforward loop with different controllers induces additional synchronous- or low-frequency instability issues, whereas the q-axis voltage feedforward loop does not have such adverse effect. Therefore, the paralleled dc-link voltage and q-axis voltage feedforward control-based synchronization scheme is recommended. Experimental tests of GFM converters with different grid impedances are performed. The results confirm the effectiveness of theoretical analysis and of the proposed control approach.

KW - constant-power dynamics

KW - dc-link voltage control

KW - Grid-forming control

KW - low-frequency oscillation

KW - synchronous resonance

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T2 - 2022 IEEE Energy Conversion Congress and Exposition, ECCE 2022

Y2 - 9 October 2022 through 13 October 2022

ER -

Flexible Synchronization Control for Grid-Forming Converters with Regulated DC-Link Dynamics

Abstract

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Bibliographical note

Keywords

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Stability and Control of Grid-Forming Converters with Regulated DC-Link Dynamics

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