|
|
|
| An Active Harmonic Grid-Connecting Current Suppression Strategy for Hierarchical Control Based Microgrid |
| Feng Wei1, Sun Kai1, Guan Yajuan2, Josep M. Guerrero2, Xiao Xi1 |
1. State Key Lab of Security Control and Simulation of Power Systems and Generation Equipments Tsinghua University Beijing 100084 China;
2. Department of Energy Technology Aalborg University Aalborg 9000 Denmark |
|
|
|
|
Abstract Given that the droop controlled inverters based grid-connected microgrid (DCIGC-MG) presents low equivalent output impedance when connecting to the grid, the grid-connecting current (GCC) is distorted easily by the harmonic voltage components at the point of common coupling (PCC), and results in the increase of THDn of GCC. An active harmonic GCC suppression strategy for DCGC-MG based on hierarchical theory was proposed in this paper. Firstly, the voltage error between bus of DCGC-MG and PCC of grid was transferred to dq frame by the Park transformation. Then, an additional compensator consisting of multiple resonant voltage regulators was added into the secondary control to generate the harmonic voltage reference for inverters in the primary level. PI and multiple resonant controllers were adopted as voltage controller in the original primary level to improve the voltage tracking performance of inverter. As a result, the voltage difference between the PCC and system bus decreased, and the GCC is purified. The proposed control strategy not only reduces the steady-state hormonic current injected into the grid by the microgrid, but also suppressed the harmonic inrush currents when the microgrid connects to the distorted grid for protecting inverter. Finally, the simulation and experimental results from scaled-down laboratory prototype have verified the proposed control strategy.
|
|
Received: 20 August 2016
Published: 28 March 2018
|
|
|
|
|
|
[1] Joan Rocabert, Alvaro Luna, Frede Blaabjerg.Control of power converters in AC microgrids[J]. IEEE Transactions on Power Electronics, 2012, 27(11): 4734-4749.
[2] Barnes M, Kondoh J, Asano H.Real-world microgrids—an overview[C]//IEEE International Conference on System of Systems Engineering, SoSE '07, San Antonio, TX, USA, 2007.
[3] 黄宜平, 马晓轩. 微电网技术综述[J]. 电工技术学报, 2015, 30(1): 320-328.
Huang Yiping, Ma Xiaoxuan.Research on microgrid technology[J]. Transactions of China Electrotechnical Society, 2015, 30(1): 320-328.
[4] 黄伟, 孙昶辉, 吴子平, 等. 含分布式发电系统的微网技术研究综述[J]. 电网技术, 2009, 33(9): 14-18.
Huang Wei, Sun Changhui, Wu Ziping, et al.A review on microgrid technology containing distributed generation system[J]. Power System Technology, 2009, 33(9): 14-18.
[5] Josep M Guerrero, Juan C Vasquez, José Matas, et al.Hierarchical control of droop-controlled AC and DC microgrids—a general approach toward standardi- zation[J]. IEEE Transactions on Industrial Elec- tronics, 2011, 58(1): 158-172.
[6] Shafiee Q, Guerrero J M, Vasquez J C.Distributed secondary control for islanded microgrids—a novel approach[J]. IEEE Transactions on Power Electronics, 2013, 29(2): 1018-1031.
[7] Liu Shichao, Wang Xiaoyu, Liu P X.Impact of communication delays on secondary frequency control in an islanded microgrid[J]. IEEE Transactions on Industrial Electronics, 2014, 62(4): 2021-2031.
[8] Bahramirad S, Reder W, Khodaei A.Reliability- constrained optimal sizing of energy storage system in a microgrid[J]. IEEE Transactions on Smart Grid, 2012, 3(4): 2056-2062.
[9] Tang Xisheng, Deng Wei, Qi Zhiping.Investigation of the dynamic stability of microgrid[J]. IEEE Transactions on Power Systems, 2013, 29(2): 698-706.
[10] Lee Tzung-Lin, Cheng Po-Tai.Design of a new cooperative harmonic filtering strategy for distributed generation interface converters in an islanding network[J]. IEEE Transactions on Power Electronics, 2007, 22(5): 1919-1927.
[11] Hamzeh M, Karimi H, Mokhtari H.Harmonic and negative-sequence current control in an islanded multi-bus MV microgrid[J]. IEEE Transactions on Smart Grid, 2014, 5(1): 167-176.
[12] He Jinwei, Li Yunwei, Blaabjerg F.An enhanced islanding microgrid reactive power, imbalance power, and harmonic power sharing scheme[J]. IEEE Transactions on Power Electronics, 2014, 30(6): 3389-3401.
[13] Savaghebi M, Jalilian A, Vasquez J C.Secondary control scheme for voltage unbalance compensation in an islanded droop-controlled microgrid[J]. IEEE Transactions on Smart Grid, 2012, 3(2): 797-807.
[14] Liu Quanwei, Tao Yong, Liu Xunhao, et al.Voltage unbalance and harmonics compensation for islanded microgrid inverters[J]. IET Power Electronics, 2014, 7(5): 1055-1063.
[15] 鲍薇, 胡学浩, 李光辉, 等. 独立型微电网中基于虚拟阻抗的改进下垂控制[J]. 电力系统保护与控制, 2013, 41(16): 8-13.
Bao Wei, Hu Xuehao, Li Guanghui, et al.An improved droop control strategy based on virtual impedance in islanded micro-grid[J]. Power System Protection and Control, 2013, 41(16): 8-13.
[16] 刘红, 林明潮. 基于新型正序提取器的并网与独立双模式无缝切换策略[J]. 电工技术学报, 2015, 30(9): 53-60.
Liu Hong, Lin Mingchao.A seamless transition strategy between gird-tied and stand-alone modes for inverters based on a new positive component detector[J]. Transactions of China Electrotechnical Society, 2015, 30(9): 53-60.
[17] 冯伟, 孙凯, 关雅娟, 等. 孤立微电网中基于输出电压复合控制的电压源型并网逆变器谐波电流抑制策略[J]. 电工技术学报, 2016, 31(7): 72-80.
Feng Wei, Sun Kai, Guan Yajuan, et al.An active harmonic grid-connecting current suppression strategy for the droop control based microgrid based on the hierarchical control[J]. Transactions of China Electrotechnical Society, 2016, 31(7): 72-80.
[18] He Jinwei, Li Yunwei Munir M S. A Flexible harmonic control approach through voltage- controlled DG-grid interfacing converters[J]. IEEE Transactions on Industrial Electronics, 2011, 59(1): 444-455.
[19] He Jinwei, Li Yunwei, Blaabjerg F.Flexible micro- grid power quality enhancement using adaptive hybrid voltage and current controller[J]. IEEE Transactions on Industrial Electronics, 2013, 61(6): 2784-2794. |
|
|
|
2018, Vol. 33 
