Small Signal Modeling of Inverter-based Grid-Connected Microgrid to Determine the Zero-Pole Drift Control with Dynamic Power Sharing Controller

E. Pathan, S. A. Zulkifli, U. B. Tayab, R. Jackson


This paper presents a small signal state space modeling of three-phase inverter-based microgrid (MG) system with consideration of improved droop control. The complete system matrices for one distribution source-grid connects to the local load have been elaborated by applying high, medium and low-frequency clusters to the system without considering the switching action on the inverter during power-sharing. Moreover, the final matrices will be used to determine the location of the eigenvalues for the control parameters gains due to dynamic effect of the MG, by observing the root locus graph on cluster identification. Sensitivity analysis of all types of frequency cluster showed that power-sharing control parameters such as load current, source current, and inverter voltage are influencing system stability and must be considered when designing the proportional-integral (PI) control when different load scenarios have been applied from the zero-pole drifting. Those eigenvalues of the system model are indicating the frequency and damping oscillatory components when there is sudden changed at the inverter-grid connection. The matrices’ eigenvalues are being plotted using MATLAB/Simulink to identify system stability region and find the PI controller parameters.


power sharing control; microgrid; power-sharing control; small-signal stability

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F. Blaabjerg, R. Teodorescu, M. Liserre, A. V Timbus, “Overview of Control and Grid Synchronization for Distributed Power Generation Systems”, IEEE Transactions on Industrial Electronics, Vol. 53, No. 5, pp. 1398-1409, 2006

A. Vidal, F. D. Freijedo, A. G. Yepes, P. Fernandez-Comesana, J. Malvar, O. Lopez, J. Doval-Gandoy, “Assessment and optimization of the transient response of proportional-resonant current controllers for distributed power generation systems”, IEEE Transactions on Industrial Electronics, Vol. 60, No. 4, pp. 1367-1383, 2013

IEEE Standards Coordinating Committee, 1547.4-2011-IEEE Guide for Design, Operation, and Integration of Distributed Resource Island Systems with Electric Power Systems, IEEE, 2011

Y. Han, M. Luo, X. Zhao, J. M. Guerrero, L. Xu, “Comparative Performance Evaluation of Orthogonal-Signal-Generators-Based Single-Phase PLL Algorithms - A Survey”, IEEE Transactions on Power Electronics, Vol. 31, No. 5, pp. 3932-3944, 2016

P. Shen, Y. Han, C. Lu, J. M. Guerrero, “Small-signal modeling of the PVR-based AD scheme and controller design for three-phase standalone DG system”, Journal of Electrical Engineering & Technology, Vol. 11, No. 5, pp. 1165-1178, 2016

F. Katiraei, M. R. Iravani, P. W. Lehn, “Small-signal dynamic model of a micro-grid including conventional and electronically interfaced distributed resources”, IET Generation, Transmission & Distribution, Vol. 1, No. 3, pp. 369-378, 2007

N. Pogaku, M. Prodanovic, T. C. Green, “Modeling, analysis and testing of autonomous operation of an inverter-based microgrid”, IEEE Transactions on Power Electronics, Vol. 22, No. 2, pp. 613-625, 2007

M. Rasheduzzaman, J. Mueller, J. W. Kimball, “Small-signal modeling of a three-phase isolated inverter with both voltage and frequency droop control”, 2014 IEEE Applied Power Electronics Conference and Exposition, Fort Worth, USA, March 16-20, 2014

W. R. Issa, M. A. Abusara, S. M. Sharkh, “Control of Transient Power during Unintentional Islanding of Microgrids”, IEEE Transactions on Power Electronics, Vol. 30, No. 8, pp. 4573-4584, 2015

U. B. Tayab, M. Azrik, B. Roslan, L. J. Hwai, M. Kashif, “A review of droop control techniques for microgrid”, Renewable and Sustainable Energy Reviews, Vol. 76, pp. 717-727, 2017

W. Issa, M. Abusara, S. Sharkh, T. Mallick, “A small signal model of an inverter-based microgrid including DC link voltages”, 17th European Conference on Power Electronics and Applications, Geneva, Switzerland, September 8-10, 2015

U. B. Tayab, Q. M. Humayun, “Enhanced droop controller for operating parallel-connected distributed-generation inverters in a microgrid”, Journal of Renewable and Sustainable Energy, Vol. 10, No. 4, 2018

U. B. Tayab, M. Kashif, “A modified droop controller for parallel operation of single-phase inverters in Islanded microgrid”, International Journal of Intelligent Engineering & Systems, Vol. 10, No. 4, pp. 11-17, 2017

R. S. Herrera, P. Salmeron, J. R. Vazquez, S. P. Litran, A. Perez, “Generalized instantaneous reactive power theory in poly-phase power systems”, 13th European Conference on Power Electronics and Applications, Barcelona, Spain, September 8-10, 2009

A. Tuladhar, H. Jin, T. Unger, K. Mauch, “Control of parallel inverters in distributed AC power systems with consideration of line impedance effect”, IEEE Transactions on Industrial Applications, Vol. 36, No. 1, pp. 131-138, 2000

B. Zhang, X. Yan, D. Li, X. Zhang, J. Han, X. Xiao, “Stable Operation and Small-Signal Analysis of Multiple Parallel DG Inverters Based on a Virtual Synchronous Generator Scheme”, Energies, Vol. 11, No. 1, pp. 1-22, 2018

K. Hashmi, M. M. Khan, S. Habib, H. Tang, “An Improved Control Scheme for Power Sharing between Distributed Power Converters in Islanded AC Microgrids”, International Conference on Frontiers of Information Technology, Islamabad, Pakistan, December 8-20, 2017

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