A New Control Method for Single-Phase Grid-Connected Inverter Using Instantaneous Power Theory

Document Type : Research paper

Authors

1 Faculty of Electrical and Computer Engineering, University of Birjand

2 Faculty of Engineering, Ferdowsi University of Mashhad

Abstract

Because of installation for local consumers and since it is free of all contaminations, connecting photovoltaic cells to the grid via single-phase inverter is significantly on the rise. In this paper, a new simple current control is proposed for a single-phase grid-connected voltage source inverter. Using the PQ theory and modelling a single-phase system as an unbalanced three-phase system, a method is provided for reference current generation. In the proposed method, it is not necessary to generate a fictitious phase for the current signal. Also, the removal of adjusting filter parameters which were used to generate fictitious current signal increases the simplicity of the control system and reduces computational efforts, especially in the presence of distortion in the current. The simulation results confirm that the proposed method provides a precise and fast current control with minimum harmonic distortions.

Keywords

Main Subjects


[1]     M. Schmela,“Global market outlook for solar power/2016-2020” , EPIA, Belgium, 2016.
[2]     H. Komurcugil, N. Altin, S. Ozdemir and I. Sefa “Lyapunov-function and proportional-resonant-based control strategy for single-phase grid-connected VSI with LCL filter,” IEEE Trans. Ind. Electron., vol. 63, no. 5, pp. 2838-2849, 2016.
[3]     M. Monfared and S. Golestan “Control strategies for single-phase grid integration of small-scale renewable energy sources: A review,” Renewable SustainableEnergy Rev., vol. 16, pp. 4982-4993, 2012.
[4]     Y. Shi, B. Liu and S. Duan “Low-frequency input current ripple reduction based on load current feedforward in a two-stage single-phase inverter,” IEEE Trans. Power Electron., vol. 31, no. 11, pp. 7972-7985, 2016.
[5]     Y. Hu, Y. Du, W. Xiao, S. Finney and W. Cao “DC-link voltage control strategy for reducing capacitance and total harmonic distortion in single-phase grid-connected photovoltaic inverters,”  IET Power Electron., vol. 8, no. 8, pp. 1386-1393, 2015.
[6]     G. Zhu, X. Ruan, L. Zhang and X. Wang “On the reduction of second harmonic current and improvement of dynamic response for two-stage single-phase inverter,” IEEE Trans. Power Electron., vol. 30, no. 2, pp. 1028-1041, 2015.
[7]     M. Banaei “Multi-stage DC-AC converter based on new DC-DC converter for energy conversion,” J. Oper. Autom. Power Eng., vol. 4, no. 1, pp. 42-53, 2016.
[8]     M. Kumar; R. Gupta “Sampled-Time Domain Analysis of Digitally Implemented Current Controlled Inverter,”  IEEE Trans. Ind. Electron., vol. PP, no.99, pp.1-1, 2016
[9]     F. Wu, F. Feng, L. Luo J. Duan and L. Sun “Sampling period online adjusting-based hysteresis current control without band with constant switching frequency,” IEEE Trans. Ind. Electron., vol. 62, no. 1, pp. 270-277, 2015.
[10]  S. Gautam and R. Gupta “Unified time-domain formulation of switching frequency for hysteresis current controlled AC/DC and DC/AC grid connected converters,” IET Power Electron., vol. 6, pp. 683-692, 2013.
[11]  Z. Yao and L. Xiao “Control of single-phase grid-connected inverters with nonlinear loads,” IEEE Trans. Ind. Electron., vol. 60, pp. 1384-138, 2013.
[12]  F. Wu, L. Zhang, and Q. Wu “Simple unipolar maximum switching frequency limited hysteresis current control for grid-connected inverter,” IET Power Electron., vol. 7, pp. 933-945, 2014.
[13]  M. Ebrahimi, S. A. Khajehoddin and M. Karimi-Ghartemani “Fast and robust single-phase DQ current controller for smart inverter applications,” IEEE Trans. Power Electron., vol. 31, no. 5, pp. 3968-3976, 2016.
[14]  S. Somkun and V. Chunkag “Unified unbalanced synchronous reference frame current control for single-phase grid-connected voltage-source conver-ters,” IEEE Trans. Ind. Electron., vol. 63, no. 9, pp. 5425-5436, 2016.
[15]  Shuhui Li, Xingang Fu, Malek Ramezani, Yang Sun, Hoyun Won “A novel direct-current vector control technique for single-phase inverter with L, LC and LCL filters,” Electr. Power Syst. Res., vol. 125, pp. 235-244, 2015
[16]  B. Bahrani, M. Vasiladiotis, andA. Rufer “High-order vector control of grid-connected voltage-source converters with LCL-filters,” IEEE Trans. Ind. Electron., vol. 61, pp. 2767-2775, 2014.
[17]  M. Monfared, S. Golestan, and J. M. Guerrero “Analysis, design, and experimental verification of a synchronous reference frame voltage control for single-phase inverters,” IEEE Trans. Ind. Electron., vol. 61, pp. 258-269, 2014.
[18]  T. Ye, N. Dai, C. S. Lam, M. C. Wong and J. M. Guerrero “Analysis, design, and implementation of a quasi-proportional-resonant controller for a multifunctional capacitive-coupling grid-connected inverter,” IEEE Trans. Ind. Appl., vol. 52, no. 5, pp. 4269-4280, 2016.
[19]  G. Shen, X. Zhu, J. Zhang and D. Xu “A new feedback method for PR current control of LCL-filter-based grid-connected inverter,” IEEE Trans. Ind. Electron., vol. 57, no. 6, pp. 2033-2041,2010.
[20]  M. Castilla, J. Miret, J. Matas, L. G. d. Vicuna, and J. M. Guerrero “Linear current control scheme with series resonant harmonic compensator for single-phase grid-connected photovoltaic inverters,” IEEE Trans. Ind. Electron., vol. 55, pp. 2724-2733, 2008.
[21]  M. Castilla, J. Miret, J. Matas, L. G. d. Vicuna, and J. M. Guerrero “Control design guidelines for single-phase grid-connected photovoltaic inverters with damped resonant harmonic compensators,” IEEE Trans. Ind. Electron., vol. 56, pp. 4492-4501, 2009.
[22]  J. He and Y. W. Li “Hybrid voltage and current control approach for DG-grid interfacing converters with LCL filters,” IEEE Trans. Ind. Electron., vol. 60, pp. 1797-1809, 2013.
[23]  H. Akagi, E. H. Watanabe, M. Aredes, Instantaneous power theory and applications to power conditioning, Wiley-IEEE Press, 2007, pp. 41-107.
[24]  W. Song, Z. Deng, S. Wang and X. Feng “A simple model predictive power control strategy for single-phase PWM converters with modulation function optimization,” IEEE Trans. Power Electron., vol. 31, no. 7, pp. 5279-5289, 2016.
[25]  V. Khadkikar and A. Chandra “A novel structure for three-phase four-wire distribution system utilizing unified power quality conditioner (UPQC),” IEEE Trans. Ind. Appl., vol. 45, no. 5, pp. 1897-1902, 2009.
[26]  R. I. Bojoi, L. R. Limongi, D. Roiu and A. Tenconi “Enhanced power quality control strategy for single-phase inverters in distributed generation systems,” IEEE Trans. Power Electron., vol. 26, no. 3, pp. 798-806, 2011.
[27]  X. Zong, A single phase grid connected DC/AC inverter with reactive power control for residential PV application, M.S. Thesis, Dept. Elec. Eng., Toronto Univ., Toronto, 2011.
[28]  P. T. Krein, R. S. Balog, and M. Mirjafari “Minimum energy and capacitance requirements for single-phase inverters and rectifiers using a ripple port,” IEEE Trans. Power Electron. vol. 27, pp. 4690-4698, 2012.
[29]  A. Reznik, M. G. Sim, A. Al-Durra, and S. M. Muyeen “Filter design and performance analysis for grid-interconnected systems,” IEEE Trans. Ind. Appl., vol. 50, pp. 1225-1232, 2014.
[30]  M. Farhadi Kangarlu, E. Babaei, F. Blaabjerg “An LCL-filtered single-phase multilevel inverter for grid integration of PV systems,” J. Oper. Autom. Power Eng., vol. 4, no. 1, pp. 54-65, 2016.