Abstract：Islanding protection is necessary for the distributed generation (DG) systems, but it is difficult for some traditional methods such as frequency or phase variation methods to detect the islanding effect when the power generated by the DG systems matches with the demand power of the local load. The islanding detection capabilities about different disturbing signals are analyzed and even harmonic current disturbing signal suiting to multi-inverter DG system is available in this paper. Combining with a zero-crossing frequency detector, the positive feedback loop with even harmonic current disturbance is introduced to detect the islanding phenomenon. Output current reference in the grid-connected inverter is affected by a minute disturbance signal in general. Once the islanding occurs, the positive feedback of disturbance current makes the voltage frequency at the point of common coupling go beyond a preset threshold value. It is easy to design the software program, less to inject the current harmonics into the grid, quick to detect the islanding effect, equal to form the multi-inverter system. Simulation and experimental results verify that the method is effective and reliable.
张琦, 孙向东, 钟彦儒, 任碧莹. 用于分布式发电系统孤岛检测的偶次谐波电流扰动法[J]. 电工技术学报, 2011, 26(7): 112-119.
Zhang Qi, Sun Xiangdong, Zhong Yanru, Ren Biying. Even Harmonic Current Disturbing Method for Islanding Detection in the Distributed Power Generation Systems. Transactions of China Electrotechnical Society, 2011, 26(7): 112-119.
[1] IEEE Standard 929—2000. IEEE Recommended Practice for Utility Interface of Photovoltaic(PV) Systems[S]. [2] Mihai Ciobotaru, Vassilios G Agelidis, Remus Teodorescu, et al. Accurate and less-disturbing active antiislanding method based on PLL for grid- connected converters[J]. IEEE Transactions on Power Electronics, 2010, 25(6): 1576-1584. [3] Hurng Liahng Jou, Wen Jung Chiang, Jinn Chang. A Simplified control method for the grid-connected inverter with the function of islanding detection[J]. IEEE Transactions on Power Electronics, 2008, 23(6): 2775-2783. [4] 郭小强, 赵清林, 邬伟扬.光伏并网发电系统孤岛检测技术[J].电工技术学报, 2007, 22(4):157-162. Guo Xiaoqiang, Zhao Qinglin, Wu Weiyang. Islanding detection method for photovoltaic grid-connected power system[J]. Transactions of China Electrotechnical Society, 2007, 22(4): 157-162. [5] 陈卫民, 陈国呈, 吴春华, 等.基于分布式并网发电的新型孤岛检测研究[J].电工技术学报, 2007, 22(8): 114-118. Chen Weimin, Chen Guocheng, Wu Chunhua, et al. Research on a novel islanding detection based on grid-connected distributed generations[J]. Transactions of China Electrotechnical Society, 2007, 22(8): 157-162. [6] 刘芙蓉, 康勇, 段善旭, 等. 主动移频式孤岛检测方法的参数优化[J]. 中国电机工程学报, 2008, 28(1): 95-99. Liu Furong, Kang Yong, Duan Shanxu, et al. Parameter optimization of active frequency drift islanding detection method[J]. Proceedings of the CSEE, 2008, 28(1): 95-99. [7] 任碧莹, 孙向东, 钟彦儒, 等. 用于单相分布式发电系统孤岛检测的新型电流扰动方法[J]. 电工技术学报, 2009, 24(7): 157-163. Ren Biying, Sun Xiangdong, Zhong Yanru, et al. A novel current-disturbing method for islanding detection in single-phase distribute power generation systems[J]. Transactions of China Electrotechnical Society, 2009, 24(7): 157-163. [8] Sun Xiangdong, Zhang Qi, Ren Biying, et al. A novel digital phase-locked loop for distributed grid- connected power generation systems under unbalanced and distorted utility conditions[C]. PEDG2010, 2010: 813-817. [9] Zhang Qi, Sun Xiangdong, Zhong Yanru, et al. A novel digital phase-locked-loop for single-phase grid-connected power generation systems[C]. IPEMC2010, Sapporo, 2010: 349-353. [10] Lopes L A C, Huili S. Performance assessment of active frequeny drifting islanding detection methods[J]. IEEE Transactions Energy Conversion, 2006, 21(1): 171-180. [11] L A C Lopes, Z Yongzheng. Islanding detection assessment of multi-inverter systems with active frequency drifting methods[J]. IEEE Transactions Power Delivery, 2008, 23(1): 480-486. [12] Zeineldin H H, Kennedy S. Sandia frequency-shift parameter selection to eliminate nondetection zones[J]. IEEE Transactions Power Delivery, 2009, 24(1): 486-487. [13] Sanchis P, Marroyo L, Coloma J. Design methodology for the frequency shift method of islanding prevention and analysis of its detection capability[C]. Progress in Photovoltaics: Research and Applications, 2005, 13(5): 409-428. [14] Timbus A V, Rodriguez P, Teodorescu R, et al. Line impedance estimation using active and reactive power variations[C]. Proceedings of PESC, 2007: 1273- 1279. [15] 刘方锐, 段善旭, 康勇, 等. 多机光伏并网逆变器的孤岛检测技术[J].电工技术学报, 2010, 25(1): 167-171. Liu Fangrui, Duan Shanxu, Kang Yong, et al. Islanding detection method for multiple PV converters system[J]. Transactions of China Electrotechnical Society, 2010, 25(1): 167-171.
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