## 1 Introduction
Typically used passive methods are under/over voltage and frequency, phase jump in voltage, rate of change of frequency, rate of change of power and total harmonic distortion methods [1]. Some signal processing techniques combine with passive strategies to overcome drawbacks of passive methods just like wavelet transform (WT), wavelet packet transform (WPT) and S-transform (ST) [20, 21, 22, 23, 24, 25]. Some recent contributions are fuzzy logic, artificial neural network, decision tree, Naive Bayesian classifier, Random Forest classifier are established in [2, 20, 21, 26, 27, 28]. Active and passive islanding detection schemes are combined to form hybrid methods. These methods are developed to obtain the advantages of both types. A brief overview of hybrid methods is discussed in [2]. After observing the literature review, it has been realized that both the indices and rate of changes have been used for islanding detection in some contributions. 16 different rates of changes are considered and a new passive parameter based on the rate of change of frequency over reactive power (df/dq) is proposed in terms of sensitivity and performance. This technique is fast and simple. However, small NDZ is still a problem in this technique. Moreover, indices are not taken into account in this work [29]. A mathematical morphology-based method has used 6 passive indices for better effectiveness of protection scheme. Reactive power is the best in terms of simple methodology and quick implementation. However, NDZ still exists in this method [30]. A zero NDZ based and quick implementable passive islanding detection technique employed 2 passive indices viz. voltage and frequency variation. However, the use of 2 passive indices makes the algorithm complex and increases the computational burden [6]. Furthermore, few methods consider 2 passive indices for islanding detection such as negative sequence volt-age/current utilized phaslet algorithm [31], voltage/positive sequence voltage phase angle [32] and transient index voltage/positive sequence angle superimposed current [33]. The precision of these methods was high and have almost zero NDZ. Though, the usage of more indices makes the algorithm slightly complex. Some recent contributions have been considered in the literature including VPA techniques. Passive methods have been developed in [31; 32; 33; 34; 35; 36; 37; 38; 39] to minimize the NDZ and tripping time. In [40], the active islanding detection method for inverter type DG is employed based on voltage phase angle. A difference between the instantaneous and nominal voltage phase angle (VPA) of a distributed generation (DG) is applied to inverter-based interface control. However, inconsequential power quality issue is still present in this method. The active method for inverter base DG has been presented in [41] uses voltage phase angle of inverter-based DG as a feedback signal to change powers references. However, insignificant power quality issues still exist. In [42], the passive islanding detection method has been developed by combining under frequency (UF), over frequency (OF), rate of change of frequency (ROCOF), phase angle difference, rate of change of voltage (ROCOV) and rate of change of phase angle difference (ROCOPAD). This method has the advantages of zero NDZ and fast tripping time. However, the algorithm becomes complex due to using multiple passive parameters. The communication-based method has been used in [43] by employing proposed parameters of voltage phase angle difference and rate of change of voltage phase angle difference (ROCOVPAD). Zero NDZ, fast detection time and no power quality impacts on the system are the advantages of this method. However, the use of GPS and wireless modems is economically not good from an economical perspective. The abovementioned passive islanding detection methods are either suffer from one of the issues like NDZ, power quality issue, large tripping time or have complexity in the algorithm.