On DC-Side Impedance Frequency Characteristics Analysis and DC Voltage Ripple Prediction under Unbalanced Conditions for MMC-HVDC System Based on Maximum Modulation Index

- Journal title : Journal of Power Electronics
- Volume 16, Issue 1, 2016, pp.319-328
- Publisher : The Korean Institute of Power Electronics
- DOI : 10.6113/JPE.2016.16.1.319

Title & Authors

On DC-Side Impedance Frequency Characteristics Analysis and DC Voltage Ripple Prediction under Unbalanced Conditions for MMC-HVDC System Based on Maximum Modulation Index

Liu, Yiqi; Chen, Qichao; Li, Ningning; Xie, Bing; Wang, Jianze; Ji, Yanchao;

Liu, Yiqi; Chen, Qichao; Li, Ningning; Xie, Bing; Wang, Jianze; Ji, Yanchao;

Abstract

In this study, we first briefly introduce the effect of circulating current control on the modulation signal of a modular multilevel converter (MMC). The maximum modulation index is also theoretically derived. According to the optimal modulation index analysis and the model in the continuous domain, different DC-side output impedance equivalent models of MMC with/without compensating component are derived. The DC-side impedance of MMC inverter station can be regarded as a series xR + yL + zC branch in both cases. The compensating component of the maximum modulation index is also related to the DC equivalent impedance with circulating current control. The frequency characteristic of impedance for MMC, which is observed from its DC side, is analyzed. Finally, this study investigates the prediction of the DC voltage ripple transfer between two-terminal MMC high-voltage direct current systems under unbalanced conditions. The rationality and accuracy of the impedance model are verified through MATLAB/Simulink simulations and experimental results.

Keywords

DC voltage ripple;Fault prediction;High-voltage direct current;Impedance prediction;Maximum modulation index;Modular multilevel converter;

Language

English

Cited by

References

1.

J. M. Carrasco, L. G. Franquelo, J. T. Bialasiewicz, and E. Galvan, “Power-electronic systems for the grid integration of renewable energy sources: A survey, ” IEEE Trans. Ind. Electron., Vol. 53, No. 4, pp. 1002-1016, Jun. 2006.

2.

K. Shen, D. Zhao, J. Mei, and L. M. Tolbert. “Elimination of harmonics in a modular multilevel converter using particle swarm optimization-based staircase modulation strategy,” IEEE Trans. Ind. Electron., Vol. 61, No. 10, pp. 5311-5322, Oct. 2014.

3.

P. M. Meshram and V. B. Borghate, “A simplified nearest level control (NLC) voltage balancing method for modular multilevel converter (MMC),” IEEE Trans. Power Electron., Vol. 30, No. 1, pp. 450-462, Jan. 2015.

4.

M. Glinka and R. Marquardt. “A new ac/dc multilevel converter family,” IEEE Trans. Ind. Electron., Vol. 52, No. 3, pp. 662-669, 2005.

5.

Q. R. Tu and Z. Xu, “Impact of sampling frequency on harmonic distortion for modular multilevel converter,” IEEE Trans. Power Del., Vol. 26, No. 1, pp. 298-306, Jan. 2011.

6.

K. Ilves, A. Antonopoulos, S. Norrga, H.-P. Nee, “Steady-state analysis of interaction between harmonic components of arm and line quantities of modular multilevel converters,” IEEE Trans. Power Electron., Vol. 27, No. 1, pp. 57-68, Jan. 2012.

7.

Y. L. Li, E. A. Jones, and F. Wang. "Analysis of the relationship between switching frequency and sub-module capacitor unbalanced voltage for a modular multilevel converter," in Proc. Applied Power Electronics Conference and Exposition(APEC), pp. 220-224, Mar. 2014.

8.

M. Y. Guan and Z. Xu. “Modeling and control of a modular multilevel converter-based HVDC system under unbalanced grid conditions,” IEEE Trans. Power Electron., Vol. 27, No. 12, pp. 4858-4867, Dec. 2012.

9.

J.-W. Moon, C.-S. Kim, J.-W. Park, and D.-W. Kang, “Circulating current control in MMC under the unbalanced voltage,” IEEE Trans. Power Del., Vol. 28, No. 3, pp. 1952-1959, Jul. 2013.

10.

Q. R. Tu, Z. Xu, and L. Xu. “Reduced switchingfrequency modulation and circulating current suppression for modular multilevel converters,” IEEE Trans. Power Del., Vol. 26, No. 3, pp. 2009-2017, Jul. 2013.

11.

S. H. Li, X. L. Wang, Z. Q. Yao, T. Li, and Z. Peng, “Circulating current suppressing strategy for MMC-HVDC based on nonideal proportional resonant controllers under unbalanced grid conditions,” IEEE Trans. Power Electron., Vol. 30, No. 1, pp. 387-397, Jan. 2015.

12.

M. Hagiwara and H. Akagi, “Control and experiment of pulse width modulated modular multilevel converters,” IEEE Trans. Power Electron., Vol. 24, No. 7, pp. 1737-1746, Jul. 2009.

13.

S. Rohner, S. Bernet, M. Hiller, and R. Sommer, “Modulation, losses, and semiconductor requirements of modular multilevel converters,” IEEE Trans. Ind. Electron., Vol. 57, No. 8, pp. 2633–2642, Aug. 2010.

14.

D. C. Ludois and G. Venkataramanan, “Simplified terminal behavioral model for a modular multilevel converter,” IEEE Trans. Power Electron., Vol. 29, No. 4, pp. 1622-1631, Apr. 2014.

15.

P. F. Hu and D. Z. Jiang, “A level-increased nearest level modulation method for modular multilevel converters,” IEEE Trans. Power Electron., Vol. 30, No. 4, pp.1836-1842, Apr. 2015.

16.

Q. Song, W. H. Liu, X. Q. Li, and H. Rao, “A steady-state analysis method for a modular multilevel converter,” IEEE Trans. Power Electron., Vol. 28, No. 8, pp. 3702-3713, Aug. 2013.

17.

X. J. Shi, Z. Q. Wang, B. Liu, Y. Q. Liu, L. M. Tolbert, and F. Wang, “Characteristic investigation and control of a modular multilevel converter-based HVDC system under single-line-to-ground fault conditions,” IEEE Trans. Power Electron., Vol. 30, No. 1, pp. 408-421, Jan. 2015.

18.

Q. R. Tu, Z. Xu, Y. Chang, and L. Guan, “Suppressing DC voltage ripples of MMC-HVDC under unbalanced grid conditions,” IEEE Trans. Power Del., Vol. 27, No. 3, pp. 1332-1338, Jul. 2012.

19.

J.-W. Moon, C.-S. Kim, J.-W. Park, D.-W. Kang, and J.-M. Kim, “Circulating current control in MMC under the unbalanced voltage,” IEEE Trans. Power Del., Vol. 28, No. 3, pp. 1952-1959, Jul. 2013.

20.

Y. L. Li, E. A. Jones, and F. Wang, "Switching- frequency ripple in dc link voltage in a modular multilevel converter with circulating current suppressing control," in Proc. Applied Power Electronics Conference and Exposition(APEC), pp. 191-195, Mar. 2014.

21.

K. Ilves, A. Antonopoulos, S. Norrga, and H.-P. Nee, “A new modulation method for the modular multilevel converter allowing fundamental switching frequency,” IEEE Trans. Power Electron., Vol. 27, No. 8, pp. 3482-3494, Aug. 2012.

22.

Michail Vasiladiotis, "Analysis, implementation and experimental evaluation of control systems for a modular multilevel converter," PhD thesis, Royal Institute of Technology, 2009.

23.

ABB, It's time to connect with offshore wind supplement, http://www.abb.com/hvdc, 2013.