TY - JOUR
T1 - Emulation of Multi-Inverter Integrated Weak Grid via Interaction-Preserved Aggregation
AU - Liao, Shuhan
AU - Huang, Meng
AU - Zha, Xiaoming
AU - Guerrero, Josep M.
N1 - Funding Information:
Manuscript received December 1, 2019; revised January 29, 2020 and March 24, 2020; accepted April 10, 2020. Date of publication April 16, 2020; date of current version July 30, 2021. This work was supported in part by the National Natural Science Foundation of China under Grant 51637007, Grant 51877159, and Grant U1866601, and in part by VILLUM FONDEN under the VILLUM Investigator Grant 25920: Center for Research on Microgrids (CROM). The work of Josep M. Guerrero was supported by a Villum Investigator from The Villum Foundation under Grant 999730. Recommended for publication by Associate Editor Marco Liserre. (Corresponding author: Meng Huang.) Shuhan Liao, Meng Huang, and Xiaoming Zha are with the School of Electrical Engineering and Automation, Wuhan University, Wuhan 430072, China (e-mail: shuhanliao@whu.edu.cn; meng.huang@whu.edu.cn; xmzha@whu.edu.cn).
Publisher Copyright:
© 2013 IEEE.
PY - 2021/8
Y1 - 2021/8
N2 - Simplified weak grid models are widely used to emulate the nonideal power grid for the design and stability analysis of grid-connected inverters. However, the dynamic behavior of a real grid with multiple inverters is complex. In this article, an emulation method is proposed for multi-inverter integrated weak grids using an interaction-preserved aggregation model associated with grid impedance. First, the interaction among inverters in weak grids is analyzed using the state-space model and participation analysis. Then, a two-inverter aggregation is proposed for a large-scale system. This model can preserve the impact of parameters on the interaction modes (IMs) and predict the IM-related instability of multi-inverter systems. Thus, the two-inverter representation is applied to emulation to preserve interactions and to simplify the testing of multiple inverters. The emulation of the 16-inverter system is implemented on a hardware-in-the-loop (HIL) test bench with one practical inverter controller under test and the remaining parts integrated in the OPAL-RT real-time simulator. The test results show that the instability attributed to the interaction can be identified by the proposed emulation method.
AB - Simplified weak grid models are widely used to emulate the nonideal power grid for the design and stability analysis of grid-connected inverters. However, the dynamic behavior of a real grid with multiple inverters is complex. In this article, an emulation method is proposed for multi-inverter integrated weak grids using an interaction-preserved aggregation model associated with grid impedance. First, the interaction among inverters in weak grids is analyzed using the state-space model and participation analysis. Then, a two-inverter aggregation is proposed for a large-scale system. This model can preserve the impact of parameters on the interaction modes (IMs) and predict the IM-related instability of multi-inverter systems. Thus, the two-inverter representation is applied to emulation to preserve interactions and to simplify the testing of multiple inverters. The emulation of the 16-inverter system is implemented on a hardware-in-the-loop (HIL) test bench with one practical inverter controller under test and the remaining parts integrated in the OPAL-RT real-time simulator. The test results show that the instability attributed to the interaction can be identified by the proposed emulation method.
KW - Aggregation modeling
KW - grid emulation
KW - gridconnected microgrids
KW - interaction
KW - multiple inverters
UR - http://www.scopus.com/inward/record.url?scp=85111868559&partnerID=8YFLogxK
U2 - 10.1109/JESTPE.2020.2988364
DO - 10.1109/JESTPE.2020.2988364
M3 - Journal article
AN - SCOPUS:85111868559
SN - 2168-6777
VL - 9
SP - 4153
EP - 4164
JO - IEEE Journal of Emerging and Selected Topics in Power Electronics
JF - IEEE Journal of Emerging and Selected Topics in Power Electronics
IS - 4
M1 - 9069228
ER -