Compensation of Voltage and Current Imbalance in Bipolar DC Microgrids Using a Three-leg DC Electric Spring

Document Type : Original Article

Authors

Department of Electrical Engineering, Shahid Bahonar University of Kerman, Kerman, Iran

Abstract

Bipolar DC microgrids with asymmetric loading face the problems of voltage and current imbalance in two poles, which can increase the voltage deviation in microgrid buses and power losses due to the presence of current in the neutral wire. One of the suggested methods to solve the problem of voltage and current imbalance in bipolar microgrids is to use two separate DC electric springs as two controlled smart loads in positive and negative poles. This structure requires a large number of active switches, two separate battery or storage units in the DC link of these two DC electric springs, and a complex control structure. In this paper, a unified three-leg DC electric spring is proposed to compensate voltage and current imbalance in bipolar DC microgrids. Compared with two separate DC electric springs, the proposed structure has less number of active switches and due to its common DC link, only one storage set is used in its structure. The effectiveness of the proposed structure in compensating voltage and current imbalance is confirmed through simulation in the MATLAB/SIMULINK environment.

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References

[1] M. Heidari, M. A. Shamsinejad, M. Monfared, "Reducing DC Link Capacitor Capacity in Grid-Connected Solar Inverters Using a Parallel Madrasah System", No. 49, 4, pp. 1577-1590, 2019.
[2] O. Souri, M. Heydari, Ehsan Najafi, "Presentation of a new high-voltage gain DC-DC converter based on active network and coupled inductor", Journal of Electrical Engineering, University of Tabriz, vol. 50, Issue 4, pp. 1647-1659, 2019.
[3] A. Kwasinski and C. N. Onwuchekwa, “Dynamic behavior and stabilization of DC microgrids with instantaneous constant-power loads,” IEEE Trans. Power Electron., vol. 26, no. 3, pp. 822–834, 2011.
[4] H. Kakigano, Y. Miura, and T. Ise, “Distribution Voltage Control for DC Microgrids Using Fuzzy Control and Gain-Scheduling Technique,” IEEE Trans. POWER Electron., vol. 28, no. 5, pp. 2246–2258, 2013.
[5] P. C. Loh, S. Member, D. Li, Y. K. Chai, and F. Blaabjerg, “Autonomous Operation of Hybrid Microgrid With AC and DC Subgrids,” IEEE Trans. POWER Electron., vol. 28, no. 5, pp. 2214–2223, 2013.
[6] H. Kakigano, Y. Miura, and T. Ise, “Low-Voltage Bipolar-Type DC Microgrid for Super High Quality Distribution,” IEEE Trans. POWER Electron., vol. 25, no. 12, pp. 3066–3075, 2010.
[7] Esmaeil Rak Rak, Leila Miri, "Non-isolated single-switch DC-DC converter with high efficiency and gain and low input current ripple for photovoltaic applications", Journal of Electrical Engineering, University of Tabriz, Volume 49, Issue 1, pp. 181-190, 2019.
[8] N. H. van der Blij, L. M. Ramirez-Elizondo, M. T. J. Spaan, and P. Bauer, “A state-space approach to modelling DC distribution systems,” IEEE Trans. Power Syst., vol. 33, no. 1, pp. 949–950, 2018.
[9] Y. Gu, W. Li, and X. He, “Analysis and control of bipolar LVDC grid with DC symmetrical component method,” IEEE Trans. Power Syst., vol. 31, no. 1, pp. 685–694, Jan. 2016.
[10] G. Gwon, C. Kim, Y. Oh, C. Noh, T. Jung, and J. Han, “Electrical Power and Energy Systems Mitigation of voltage unbalance by using static load transfer switch in bipolar low voltage DC distribution system,” Int. J. Electr. Power Energy Syst., vol. 90, pp. 158–167, 2017.
[11] G. H. Gwon, C. H. Kim, Y. S. Oh, C. H. Noh, T. H. Jung, and J. Han, “Mitigation of voltage unbalance by using static load transfer switch in bipolar low voltage DC distribution system,” Int. J. Electr. Power Energy Syst., vol. 90, pp. 158–167, Sep. 2017.
[12] A. Bagherian, T. Nouri, M. Shaneh, M. Radmehr, "Presentation of a super-boosted DC-DC interleaved converter with zero-voltage switching capability and low voltage stress on the switches for renewable energy system applications", Journal of Electrical Engineering, University of Tabriz, Volume 52, Issue 4, Pages 217-227, 1401.
[13] G. H. Gwon, C. H. Kim, Y. S. Oh, C. H. Noh, T. H. Jung, and J. Han, “Mitigation of voltage unbalance by using static load transfer switch in bipolar low voltage DC distribution system,” Int. J. Electr. Power Energy Syst., vol. 90, pp. 158–167, Sep. 2017.
[14] K. T. Mok, M. H. Wang, S. C. Tan, and S. Y. R. Hui, “DC electric springs - A technology for stabilizing DC power distribution systems,” IEEE Trans. Power Electron., vol. 32, no. 2, pp. 1088–1105, 2017.
[15] J. Liao, N. Zhou, Y. Huang, and Q. Wang, “Unbalanced Voltage Suppression in a Bipolar DC Distribution Network Based on DC Electric Springs,” IEEE Trans. Smart Grid, vol. 11, no. 2, pp. 1667–1678, 2020.
[16] J. Liao, N. Zhou, Y. Huang, and Q. Wang, “Decoupling Control for DC Electric Spring-Based Unbalanced Voltage Suppression in a Bipolar DC Distribution System,” IEEE Trans. Ind. Electron., vol. 68, no. 4, pp. 3239–3250, 2021.
[17] M. H. Wang, K. T. Mok, S. C. Tan, and S. Y. Hui, “Multifunctional DC Electric Springs for Improving Voltage Quality of DC Grids,” IEEE Trans. Smart Grid, vol. 9, no. 3, pp. 2248–2258, 2018.
[18] M. H. Wang, S. Yan, S. C. Tan, and S. Y. R. Hui, “Hybrid-DC Electric Springs for DC Voltage Regulation and Harmonic Cancellation in DC Microgrids,” IEEE Trans. Power Electron., vol. 33, no. 2, pp. 1167–1177, 2018.
[19] A. Hosseinipour and H. Hojabri, “Small-Signal Stability Analysis and Active Damping Control of DC Microgrids Integrated with Distributed Electric Springs,” IEEE Trans. Smart Grid, vol. 11, no. 5, pp. 3737–3747, 2020.
[20] Y. Yang, S. C. Tan, and S. Y. R. Hui, “Mitigating distribution power loss of dc microgrids with DC electric springs,” IEEE Trans. Smart Grid, vol. 9, no. 6, pp. 5897–5906, 2018.
[21] M. Wang, Y. He, X. Xu, Z. Dong, and Y. Lei, “A Review of AC and DC Electric Springs,” IEEE Access, vol. 9, no. iii, pp. 14398–14408, 2021.
[22] M. Naghizadeh, H. S. Gohari, H. Hojabri, and E. Muljadi, “New Single-Phase Three-Wire Interlinking Converter and Hybrid AC/LVDC Microgrid,” IEEE Trans. Power Electron., vol. 38, no. 4, pp. 4451–4463, Apr. 2023.
[23] D. O. Neacsu, “Space vector modulation - An introduction,” IECON Proc. (Industrial Electron. Conf., vol. 1, no. 2, pp. 1583–1592, 2001.
 
Tabriz Journal of Electrical Engineering
Volume 55, Issue 2 - Serial Number 112
October 2025
Pages 311-319

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