A novel harmonic sharing scheme in islanded microgrid

For the islanded microgrid which is connected with nonlinear loads, an effective harmonic sharing method should be designed to guarantee the system stable operation. In this paper, a novel method of virtual impedance and PCC voltage compensation are proposed to achieve the harmonic sharing and voltage quality improvement at the point of common coupling (PCC). The fundamental and each harmonic currents are extracted by the fourth order band-pass filter respectively. Then large virtual impedance is added to the voltage reference for harmonic power sharing. However, large virtual impedance will cause large voltage drop at PCC. To avoid such occurrence, a PI controller is used to compensate the voltage drop without additional hardware. Simulation and experimental results validate the correctness and feasibility of the proposed method.

[1]  Frede Blaabjerg,et al.  An accurate autonomous islanding microgrid reactive power, imbalance power and harmonic power sharing scheme , 2013, 2013 IEEE Energy Conversion Congress and Exposition.

[2]  Mehdi Savaghebi,et al.  Voltage harmonic compensation of a microgrid operating in islanded and grid-connected modes , 2011, 2011 19th Iranian Conference on Electrical Engineering.

[3]  Josep M. Guerrero,et al.  Wireless-control strategy for parallel operation of distributed generation inverters , 2006, Proceedings of the IEEE International Symposium on Industrial Electronics, 2005. ISIE 2005..

[4]  Zhao Zhengming,et al.  A novel virtual impedance method for droop controlled parallel UPS inverters with wireless control , 2014, 2014 IEEE Conference and Expo Transportation Electrification Asia-Pacific (ITEC Asia-Pacific).

[5]  F. Blaabjerg,et al.  Microgrid reactive and harmonic power sharing using enhanced virtual impedance , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[6]  Jian Yang,et al.  A harmonic and reactive power sharing control strategy for islanded microgrids , 2015, 2015 Chinese Automation Congress (CAC).

[7]  Tzung-Lin Lee,et al.  Design of a New Cooperative Harmonic Filtering Strategy for Distributed Generation Interface Converters in an Islanding Network , 2007, IEEE Transactions on Power Electronics.

[8]  Tzung-Lin Lee,et al.  Selective harmonic virtual impedance for voltage source inverters with LCL filter in microgrids , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[9]  Fang Zhuo,et al.  A virtual resistance based reactive power sharing strategy for networked microgrid , 2015, 2015 9th International Conference on Power Electronics and ECCE Asia (ICPE-ECCE Asia).

[10]  Kyeong-Hwa Kim,et al.  Sliding mode harmonic compensation strategy for power quality improvement of a grid-connected inverter under distorted grid condition , 2015 .

[11]  D De,et al.  Decentralized Parallel Operation of Inverters Sharing Unbalanced and Nonlinear Loads , 2010, IEEE Transactions on Power Electronics.

[12]  Josep M. Guerrero,et al.  Cooperative control with virtual selective harmonic capacitance for harmonic voltage compensation in islanded microgrids , 2012, IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society.