Islanding detection method for inverter-based distributed generation with negligible non-detection zone using energy of rate of change of voltage phase angle

2015 ◽  
Vol 9 (15) ◽  
pp. 2337-2350 ◽  
Author(s):  
Haidar Samet ◽  
Teymoor Ghanbari ◽  
Farid Hashemi
Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5180
Author(s):  
Karthikeyan Subramanian ◽  
Ashok Kumar Loganathan

Distributed Generation (DG) has changed the power generation system to small-scale instead of large-scale generation. The demanding issue with the interconnection of DG is the detection of unintended islanding in a network. Several methods proposed in the literature show drawbacks such as high non-detection zones (NDZ) and higher tripping time. In this paper, the IEEE 13 bus distribution network with DGs like wind and solar power plants is integrated at two buses. Islanding is detected by utilizing data from a micro-synchrophasor located at the distribution grid and the DG. The micro-synchrophasor-based unintended islanding detection algorithm is based on parameters such as voltage, rate of change of voltage, frequency, rate of change of frequency, voltage phase angle difference and the rate of change of the voltage phase angle difference between the utility and the islanded grid. The proposed islanding detection algorithm discriminates between islanding and non-islanding conditions and is highly efficient under zero power mismatch conditions. The proposed method has null NDZ and satisfies the IEEE 1547 standard for DG tripping time. The effectiveness of the proposed IDM was verified when there are multiple DGs in the islanded grid. Also, the proposed method does not require additional hardware as it can be incorporated in digital relays with synchrophasor functionality.


2021 ◽  
Vol 11 (5) ◽  
pp. 7591-7597
Author(s):  
L. Bangar Raju ◽  
K. Subba Rao

Distributed Generators (DGs) are incorporated in the power distribution systems to develop green energies in microgrids. Islanding is a challenging task in a microgrid. Different types of islanding methods, e.g. local and remote methods, have been developed for handling this task, with local methods being easier to implement, while remote methods are communication-based and costly. The local methods are classified as passive, active, and hybrid, out of which the passive methods are more simple and economical. In this paper, a passive islanding detection method is proposed to detect single line to ground fault. This fault is considered to represent the 60 to 70% of the total un-intentional faults of this category. The available passive methods cannot detect islanding at lower power mismatches as the variations in voltage and frequency fall within thresholding values. In this method, the voltage signals are first retrieved at the targeted DG output and then the phase angle is estimated. Finally, the phase angle is differentiated to get Rate Of Change Of Voltage Phase Angle (ROCOVPA) to detect islanding, and then it is compared with the Rate Of Change Of Frequency (ROCOF) at zero percent power mismatch. Simulation results depict that the ROCOVPA is more effective than ROCOF. The proposed method not only reduces detection time and Non-Detection Zone (NDZ) but is also stable during non-islanding cases like load connection and disconnection to avoid nuisance tripping.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2421
Author(s):  
Xinxin Zheng ◽  
Rui Zhang ◽  
Xi Chen ◽  
Nong Sun

This paper proposes an improved active frequency drift (AFD) islanding detection method of a three-phase inverter. Different than the existing single-phase AFD method, in the three-phase system, the disturbance is added to the phase angle, which takes part in coordinate transformation calculations. Thus, the frequency drift of the three-phase reference current can be realized by the disturbance of the phase angle. It is unnecessary to add frequency drift to each phase respectively with the proposed method, which can simplify the control system. Furthermore, the non-detection zone can be eliminated by updating certain parameters; therefore, the detection method is sensitive. In this paper, the application of the proposed method in a digital control system is discussed in detail. The non-detection zone is analyzed, and an elimination method is proposed. Finally, the simulation and experimental results are given to verify the theoretical analysis.


2013 ◽  
Vol 318 ◽  
pp. 597-600
Author(s):  
Dong Xie ◽  
Xing Zhang

In the area of renewable energy technologies, islanding of distributed generation system needs to be prevented due to safety reasons and to ensure quality of power supplied to the customers. Several islanding detection methods based on passive and active schemes have been proposed in the literature. Passive methods have a large non detection zone (NDZ), While active schemes degrade power quality. This paper proposed a new passive islanding detection method which combines the Wavelet-transform and neural network techniques. This method can reduce the NDZ to zero without any perturbation that deteriorates the power quality. The simulation results show that the proposed islanding detection method is effective and robust in all kind of conditions.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaolong Chen ◽  
Yongli Li

In order to detect islanding nondestructively, an islanding detection method for microgrid is proposed based on adaptive and periodic disturbance on the reactive power output of inverter-based distributed generation (DG). The first two parts of the disturbance in a cycle form a symmetric triangular shape and the disturbance can adaptively adjust its peak value and cycle time for two purposes. One is to minimize the total amount of the disturbance. The other is to guarantee that the absolute value of the rate of change of frequency (ROCOF) is constant during islanding, which can be utilized to be a criterion to detect islanding. The method can be applied on the DG either operating at a unity power factor or generating both active and reactive power simultaneously. Moreover, it helps to avoid the serious transient process during control strategy transformation of the DG for microgrid islanded operation. According to the anti-islanding test system in the IEEE Std. 929-2000 and IEEE Std. 1547-2003, several study cases are carried out in the PSCAD/EMTDC environment. The simulation results show that the proposed method can detect islanding rapidly and nondestructively. Moreover, it also performs effectively for the system with multiple DGs.


2013 ◽  
Vol 291-294 ◽  
pp. 2057-2062
Author(s):  
Ji Hong Zhang ◽  
Pei Hong Yang ◽  
Zhen Kui Wu

The quick & exact anti-islanding is a mandatory feature for grid-connected distributed generation system. The conventional passivity detection method has the biggish blind section and lower reliability, especially when the grid-connected inverter export power and burthen power are balanceable; the islanding detection often is disabled. And that the initiative islanding detection method is considered an effective measure, but if the arithmetic & parameter choice irrelevantly, the islanding can not be detected easily; even injected harmonic to the grid and destroy power quality. An improved voltage shift technique islanding detection arithmetic is put forward in this paper, and the correlative mathematics model is established, and the project is analyzed and studied theoretically based on IEEE Std.2009-929 criterion. The result shows the method will not affect power quality, at the same time it can detect islanding phenomenon quickly& exactly, so it is feasible.


Author(s):  
J. Rajesh Reddy ◽  
A. Pandian

<p>In recent years to meet the energy consumption demand of the world, all are working on renewable distributed generation (RDG) due to shortage of fossil fuels. The RDG systems after integrating with grid, has a disadvantage of islanding in the power system. Islanding is caused, if the RDG is supplying power to load connected due to failures in the grid. As per IEEE 1547 distributed generation (DG) interconnection standards, the islanding should be detected within 2 seconds after islanding. In this paper a hybrid islanding detection scheme is presented with rate of change of frequency (ROCOF) and reactive power injection with positive feedback. It will reduce the non detection zone (NDZ) of passive ROCOF relay to zero and can detect balanced islanding. The computer simulations are performed on MATLAB-2016. The simulations results show the effective performance of the proposed method.</p>


In this paper an effective hybrid FAT-SGO approach is proposed for islanding detection of distributed generation (DG) system. The proposed approach is the joint implementation of Feedback Artificial Tree (FAT) and Shell Game Optimization (SGO) named as FAT-SGO technique. Reducing the non-detection zone (NDZ) as near as possible and keep the output power quality unmovable is main contribution of this paper. Furthermore, this method solves the issue of establishing detection thresholds inherent in existing methods. The proposed strategy uses the rate of change of frequency (ROCOF) in DG destination location is utilized as input sets of FAT system for intelligent islanding detection. Here, FAT is trained by SGO, which extracts the different intrinsic characteristics among islanding and grid disturbance. With the extracted characteristics, the FAT method is used for classifying the disturbances in islanding and grid. For authenticating the feasibility of this strategy is authorized through various conditions and different conditions of load, switching operation, and network. The simulation of the proposal is done in MATLAB / SIMULINK and the performance in islanding and non-islanding events was studied. Statistic analysis of proposed and existing methods of mean, median and standard deviation is analyzed. DG performance is assessed by comparative analysis with current techniques.


2021 ◽  
Vol 71 (5&6) ◽  
pp. 91
Author(s):  
Dong Xie ◽  
Dajin Zang ◽  
Peng Gao ◽  
Junjia Wang ◽  
Zhu Zhu

In distributed generation systems, islanding detection is a necessary function of grid-connected inverters. In view of the performance disadvantages of traditional passive and active islanding detection methods, this paper proposes a novel passive islanding detection method. The proposed method first extracts characteristic parameters from the inverter output voltage signal and inverter output current signal through lifting wavelet transform, and then conducts the pattern recognition of these extracted characteristic parameters via BP neural network, so as to judge if there is an islanding phenomenon. As verified by the simulation and experiment results, the islanding detection method proposed in this paper is effective, and is featured by high detection speed and small non-detection zone, without affecting electric energy quality; its detection performance has been remarkably improved in comparison with that of traditional islanding detection methods.


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