近年來再生能源的重要性已逐漸升高，由儲能設備、太陽能發電系統與風力發電系統形成的小型分散式發電系統已被廣泛設置利用。通常分散式發電系統會與市電併聯運轉，所衍生的安全性問題受到相當重視。其中，孤島運轉現象係指分散式發電系統在市電系統故障跳脫時，分散式發電系統沒有檢測到此故障現象而持續向區域負載獨立供電的現象。為避免衍生包括電力維修人員感電事故等相關危害，當發生孤島運轉現象時，分散式發電系統應立即跳脫。
傳統孤島現象的偵測技術對於某些特定的負載仍然存在不可偵測區域，偵測結果容易受到區域負載條件的影響。因此，本文提出的兩階段式倍率檢測法可以克服上述之缺失，以利分散式發電系統運轉診斷。為驗證所提的孤島現象偵測法之可行性，本文利用PSIM軟體模擬系統與實作驗證，進行不同負載條件與干擾模擬等條件測試，證實本文所提的孤島現象檢測法能有效運作且具有良好的特性。

The importance of renewable energy has gradually increased in recent years. Storage systems, solar energy systems, and wind power generation systems constitute distributed generation systems, which currently are widely established. Distributed generation systems are typically connected to electricity grids. Consequently, security problems associated with such systems must be emphasized. Among the problems, the islanding effect is a phenomenon in which a distributed generation system still supplies power to a local load when the electricity grid blacks out. When an islanding event occurs, the distributed generation system should disconnect the inverter to avoid danger like electricity grid repair personnel to the hazard of electric shock.
Traditional islanding detection techniques have nondetection zones for conditions involving specific loads. In addition, the detection results are easily affected by local load conditions. To overcome the preceding disadvantages, this thesis proposes an islanding detection method that applies a two-stage magnification inspection method to facilitate the execution of diagnostics in distributed generation systems. To demonstrate the feasibility of the proposed islanding detection method, PSIM simulation software and practical implementations were applied. The simulation involved different load conditions and interference test conditions. The results prove that the proposed islanding detection method can operate effectively and that it exhibits favorable properties.

[1] G. T. Heydt, "The next generation of power distribution systems," IEEE Trans. Smart Grid, vol. 1, no. 3, pp. 225-235, 2010.
[2] G. Carpinelli, G. Celli, S. Mocci, F. Mottola, F. Pilo, and D. Proto, "Optimal integration of distributed energy storage devices in smart grids," IEEE Trans. Smart Grid, vol. 4, no. 2, pp. 985-995, 2013.
[3] M. C. Bozchalui and R. Sharma, "Optimal operation of Energy Storage in distribution systems with Renewable Energy Resources," in Proc. Power System Conference, pp. 1-6, Clemson University, USA, 2014.
[4] F. Blaabjerg, Y. Yang, K. Ma, and X. Wang, “Power electronics – the key technology for renewable energy system integration,” in Proc. 4th International Conference on Renewable Energy Research and Applications, pp. 1618-1626, Palermo, Italy, November 2015.
[5] M. Yingram, K. Chinnabutr, W. Chansanam, and R. Kudpik, "Perturbation of active islanding detection techniques in power system network." In Proc. Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology (ECTI-CON), pp. 1-4, Hua Hin, Thailand, 2015.
[6] B. Guha, R. J. Haddad, and Y. Kalaani, “A passive islanding detection approach for inverter-based distributed generation using rate of change of frequency analysis,” in Proc. IEEE SoutheastCon, pp.1-6, Fort Lauderdale, Florida, 2015.
[7] P. Mahat, Zhe Chen and B. Bak-Jensen, "Review of islanding detection methods for distributed generation," in Proc. Electric Utility Deregulation and Restructuring and Power Technologies, pp. 2743-2748, Nanjuing, China, 2008.
[8] IEEE recommended practice for utility interface of photovoltaic (PV) systems, 2000, IEEE Std 929-2000.
[9] IEEE Standard for Interconnecting Distributed Resources with Electric Power Systems, IEEE Std 1547-2003, 2003.
[10] W. Bower and M. Ropp, Evaluation of islanding detection methods for utility-interactive inverters in photovoltaic systems, 2002.
[11] M. Yingram and S. Premrudeepreechacharn, “Investigation over/under-voltage protection of passive islanding detection method of distributed generations in electrical distribution systems,” in Proc. the International Conference on Renewable Energy Research and Applications, pp. 1–5, Nagasaki, Japan, November 2012.
[12] P. Gupta, R. S. Bhatia, and D. K. Jain, "Average absolute frequency deviation value based active islanding detection technique," IEEE Trans. Smart Grid, vol. 6, no. 1, pp. 26-35, 2015.
[13] C. C. Hou and Y. C. Chen, “Active anti-islanding detection based on pulse current injection for distributed generation systems,” IET Power Electronics, vol. 6, Iss.8, pp. 1658-1667, 2013.
[14] S. Bifaaretti, A. Lidozzi, L. Solero, and F. Crescimbini, “Anti-islanding detector based on a robust PLL,” IEEE Trans. on industry applications, vol. 51, no. 1, pp. 398-405, 2015.
[15] A. Yafaoui, B. Wu, and S. Kouro, “Improved active frequency drift anti-islanding detection method for grid connected photovoltaic systems,” IEEE Trans. on power electronics, vol. 27, no. 5, pp. 2367-2375, 2012.
[16] X. L. Chen and Y. L. Li, "An islanding detection algorithm for inverter-based distributed generation based on reactive power control," IEEE Trans. Power Electron., vol. 29, no. 9, pp. 4672-4683, 2014.
[17] M. Ciobotaru, V. Agelidis, and R. Teodorescu, "Accurate and less-disturbing active anti-islanding method based on PLL for grid-connected PV inverters," in Proc. IEEE Power Electron. Spec. Conf., pp. 4569-4576, Rhodes, Greece, 2008.
[18] R. M. D. S. Filho, P. F. Seixas, and P. C. Cortizo, "A comparative study of three-phase and single-phase PLL algorithms for grid-connected systems," in Proc. INDUSCON Conf. , pp. 1-7, Recife, Brazil, 2006.
[19] A. B. Shitole, H. M. Suryawanshi, and S. Sathyan, “Comparative evaluation of synchronization techniques for grid interconnection of renewable energy sources,” Proc. IECON 2015, pp.1436-1441, Yokohama, Japan.
[20] N. Mohan, T. M. Undeland, and W. P. Robbins, Power Electronics-Converters, Applications and Design, 2003, Wiley.
[21] W. Y. Wu, X. Q. Guo, and H. R. Gu, "Phase locked loop and synchronization methods for grid-interfaced converters: A review," Przrgląd Elektrotechniczny (Electrical Review), vol. 87, no. 4, pp. 182-187, Apr. 2011.
[22] M. Kazimierkowski and L. Malesani, "Current Control Techniques for Three-Phase Voltage-Source Converters: A Survey," IEEE Trans. on Industrial Electronics Vol.45 NO 5, October 1998.
[23] U. A. Miranda, L. G. B. Rolim, and M. Aredes, "A DQ synchronous reference frame current control for single-phase converters," in Proc. IEEE 36th Power Electron. Spec. Conf., pp. 1377-1381, Recife, Brazil, 2005.
[24] 光伏逆變器反孤島效應保護測試, Chroma ATE Inc., 2013.