Analysis of load-induced unintentional islanding in Low Voltage grids with PV generators

The interest of unintentional islanding operation has recently grown in Low Voltage (LV) distribution grids because of the large penetration of Distributed Energy Resources (DERs), especially the ones based on the PhotoVoltaic (PV) energy source. The probability of unintentional islanding is increased also due to the newly introduced standards with extended frequency and voltage limits before the PV protection trips and due to the large number of PV generators, which can make ineffective the anti-islanding provisions each PV is equipped with. Moreover, interconnection standards of DERs require some additional grid support functions, such as active and reactive power regulation using P/f and Q/V droop characteristics, which can further increase the probability of unintentional islanding. In this paper, an analysis of this phenomena is provided using a simplified static and dynamic characterization of the generators and the loads. Simulation results based on Matlab and DIgSILENT tools on a simplified LV distribution network are reported together with preliminary experimental results on a lab-scale prototype.

[1]  Farrokh Albuyeh,et al.  Grid of the future , 2009, IEEE Power and Energy Magazine.

[2]  S.-K. Chung,et al.  Phase-locked loop for grid-connected three-phase power conversion systems , 2000 .

[3]  V. Blasko,et al.  Operation of a phase locked loop system under distorted utility conditions , 1997 .

[4]  F. Noor,et al.  Unintentional islanding and comparison of prevention techniques , 2005, Proceedings of the 37th Annual North American Power Symposium, 2005..

[5]  Bill Rose,et al.  Microgrids , 2018, Smart Grids.

[6]  N.W. Miller,et al.  Distributed generation islanding-implications on power system dynamic performance , 2002, IEEE Power Engineering Society Summer Meeting,.

[7]  R. Turri,et al.  Risk of unintentional islanding in LV distribution networks with inverter-based DGs , 2013, 2013 48th International Universities' Power Engineering Conference (UPEC).

[8]  F.Z. Peng,et al.  Survey of photovoltaic power systems islanding detection methods , 2008, 2008 34th Annual Conference of IEEE Industrial Electronics.

[9]  Toshihisa Funabashi,et al.  A review of islanding detection methods for distributed resources , 2003, 2003 IEEE Bologna Power Tech Conference Proceedings,.

[10]  Yongzheng Zhang,et al.  Islanding Detection Assessment of Multi-Inverter Systems With Active Frequency Drifting Methods , 2008, IEEE Transactions on Power Delivery.

[11]  Wenzhong Gao,et al.  Comparison and review of islanding detection techniques for distributed energy resources , 2008, 2008 40th North American Power Symposium.

[12]  B. Bletterie,et al.  Unintentional islanding in distribution grids with a high penetration of inverter-based DG: Probability for islanding and protection methods , 2005, 2005 IEEE Russia Power Tech.

[13]  M. Balaji,et al.  CONTROL OF POWER INVERTERS IN RENEWABLE ENERGY AND SMART GRID INTEGRATION , 2013 .

[14]  Marco Liserre,et al.  Grid Converters for Photovoltaic and Wind Power Systems , 2011 .

[15]  Zhihong Ye,et al.  Evaluation of anti-islanding schemes based on nondetection zone concept , 2003, IEEE 34th Annual Conference on Power Electronics Specialist, 2003. PESC '03..

[16]  Isao Iyoda,et al.  Modeling of load during and after system faults based on actual field data , 2003, 2003 IEEE Power Engineering Society General Meeting (IEEE Cat. No.03CH37491).