In this article, an islanding detection technique (IDT) is proposed based on applying positive feedback of wide area measurement based slip frequency at the inverter reactive power control loop. The classical Q--f droop characteristic based IDT is affected due to variations in load and active power mismatch (APM) conditions that may exist during islanding condition. To overcome these issues, an adaptive reactive power injection based IDT is proposed. Adaptiveness in the proposed method is achieved by considering the gain of the reactive power control loop as a product of rate of change of susceptance with respect to frequency seen at the inverter terminals, square of per unit point of common coupling voltage and slip frequency, which is the difference between distribution generator frequency and a reference substation bus frequency. The application of slip frequency as a positive feedback parameter injects negligible reactive power during grid side frequency disturbances and also associates with under frequency and over frequency ride through requirements. The method is least effected by load quality factor variations and APM conditions. The IDT is able to detect islanding conditions with a negligible non detection zone. Real time simulation studies are performed using dSPACE DS1104 real time controller and RTDS/RSCAD.

中文翻译：

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基于主动滑差频率的并网逆变器孤岛检测技术


在本文中，提出了一种基于在逆变器无功功率控制环路中应用基于转差频率的广域测量正反馈的孤岛检测技术（IDT）。基于经典 Q-f 下垂特性的 IDT 会受到孤岛状态期间可能存在的负载变化和有功功率失配 (APM) 条件的影响。为了克服这些问题，提出了一种基于自适应无功功率注入的 IDT。该方法的自适应性是通过将无功功率控制环路的增益考虑为电纳变化率相对于逆变器端子频率、公共耦合电压每单位点的平方和转差频率的乘积来实现的，其中是配电发电机频率与参考变电站母线频率之间的差值。转差频率作为正反馈参数的应用在电网侧频率扰动期间注入可忽略不计的无功功率，并且还与欠频和过频穿越要求相关。该方法受负载品质因数变化和 APM 条件的影响最小。 IDT 能够检测孤岛状况，且非检测区可忽略不计。使用 dSPACE DS1104 实时控制器和 RTDS/RSCAD 进行实时仿真研究。