scholarly journals Evaluation of Passive Islanding Detection Methods for Line to Ground Unsymmetrical Fault in Three Phase Microgrid Systems: Microgrid Islanding Detection Method

2021 ◽  
Vol 11 (5) ◽  
pp. 7591-7597
Author(s):  
L. Bangar Raju ◽  
K. Subba Rao
Keyword(s):  
Phase Angle ◽  
Power Distribution ◽  
Distribution Systems ◽  
Detection Method ◽  
Rate Of Change ◽  
Detection Methods ◽  
Islanding Detection ◽  
Detection Zone ◽  
Local Methods ◽  
Nuisance Tripping

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.

scholarly journals Islanding Detection Using a Micro-Synchrophasor for Distribution Systems with Distributed Generation

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5180
Author(s):  
Karthikeyan Subramanian ◽  
Ashok Kumar Loganathan
Keyword(s):  
Distributed Generation ◽  
Phase Angle ◽  
Distribution Systems ◽  
Detection Algorithm ◽  
Rate Of Change ◽  
Islanding Detection ◽  
Phase Angle Difference ◽  
Angle Difference ◽  
Voltage Phase ◽  
Islanded Grid

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.

scholarly journals Improved Three-Phase AFD Islanding Detection Based on Digital Control and Non-Detection Zone Elimination

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2421
Author(s):  
Xinxin Zheng ◽  
Rui Zhang ◽  
Xi Chen ◽  
Nong Sun
Keyword(s):  
Control System ◽  
Phase Angle ◽  
Digital Control ◽  
Detection Method ◽  
Frequency Drift ◽  
Phase System ◽  
Islanding Detection ◽  
Detection Zone ◽  
Three Phase ◽  
Three Phase Inverter

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.

A Novel Islanding Detection Method for Inverter-Based Distributed Generation Systems

2013 ◽  
Vol 318 ◽  
pp. 597-600
Author(s):  
Dong Xie ◽  
Xing Zhang
Keyword(s):  
Power Quality ◽  
Distributed Generation ◽  
Detection Method ◽  
Detection Methods ◽  
Islanding Detection ◽  
Generation System ◽  
Detection Zone ◽  
Renewable Energy Technologies ◽  
Energy Technologies

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.

scholarly journals A robust islanding detection method with zero-non-detection zone for distribution systems with DG

2021 ◽  
Vol 133 ◽  
pp. 107247
Author(s):  
Alexandre Serrano-Fontova ◽  
Juan A. Martinez ◽  
Pau Casals-Torrens ◽  
Ricard Bosch
Keyword(s):  
Distribution Systems ◽  
Detection Method ◽  
Islanding Detection ◽  
Detection Zone

An Improved Islanding Detection Method for Photovoltaic Grid-Connected System

2013 ◽  
Vol 748 ◽  
pp. 453-456
Author(s):  
Chen Xin Li ◽  
Qi Ping Yuan
Keyword(s):  
Detection Method ◽  
Harmonic Distortion ◽  
Active Power ◽  
Photovoltaic System ◽  
Detection Methods ◽  
Islanding Detection ◽  
Detection Zone ◽  
Frequency Detection ◽  
Essential Function ◽  
Maintenance Personnel

Islanding detection is a very essential function for a photovoltaic grid-connected system. Islanding phenomenons not only damage to equipment, but also endanger to the safety of the maintenance personnel. Passive islanding detection methods that use alone have considerable non-detection zone (NDZ); active islanding detection methods that use alone are that join disturbance to system, but the disturbance will cause system instability [1]. In this paper, an over/under voltage and over/under frequency detection method combines with an improved active power perturbation detection method are proposed. The photovoltaic system can be reduced non-detection zone (NDZ) with improved the power quality and reduced the total harmonic distortion (THD) through this method.

scholarly journals Research on a novel passive islanding detection method

2021 ◽  
Vol 71 (5&6) ◽  
pp. 91
Author(s):  
Dong Xie ◽  
Dajin Zang ◽  
Peng Gao ◽  
Junjia Wang ◽  
Zhu Zhu
Keyword(s):  
Distributed Generation ◽  
Bp Neural Network ◽  
Detection Method ◽  
Electric Energy ◽  
Detection Methods ◽  
Islanding Detection ◽  
Characteristic Parameters ◽  
Detection Zone ◽  
Voltage Signal ◽  
Simulation And Experiment

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.

scholarly journals Hybrid islanding detection method based on the rate of change of frequency and load impedance

2021 ◽  
Vol 10 (6) ◽  
pp. 2997-3006
Author(s):  
Hasmaini Mohamad ◽  
Zuhaila Mat Yasin ◽  
Nur Ashida Salim ◽  
Bibi Norasiqin Sheikh Rahimullah ◽  
Kanendra Naidu
Keyword(s):  
Distribution System ◽  
Detection Method ◽  
Threshold Value ◽  
Test System ◽  
Rate Of Change ◽  
Detection Methods ◽  
Islanding Detection ◽  
Load Impedance ◽  
Hybrid Detection ◽  
Active Detection

Interconnection of distributed generation (DG) in distribution system will result in formation of islands in the event of loss of main supply. This scenario is harmful to the power system, hence quick detection is critical to halt the formation of islands. Among the common passive and active detection methods available, the hybrid detection method is identified as the most reliable method. This paper proposes a new hybrid method using the combination of passive and active technique which is the rate of change of frequency (ROCOF) and load impedance, respectively. The passive method works when the value of ROCOF exceeds the threshold value which is set at 0.3Hz/s. The active method works when it detects low value of ROCOF and immediately inject a pre-specified load into the system to increase the ROCOF value up to its threshold value. Simulation study on different case studies is carried out on distribution test system to evaluate the performance of the proposed method. Results show that this method is effective in detecting any events that could result in islanding.

scholarly journals Over/Undervoltage and Undervoltage Shift of Hybrid Islanding Detection Method of Distributed Generation

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Manop Yingram ◽  
Suttichai Premrudeepreechacharn
Keyword(s):  
Control System ◽  
Distributed Generation ◽  
Hybrid Method ◽  
Detection Method ◽  
System Simulation ◽  
Detection Methods ◽  
Islanding Detection ◽  
Active Method ◽  
Passive Method ◽  
Simulation Results

The mainly used local islanding detection methods may be classified as active and passive methods. Passive methods do not perturb the system but they have larger nondetection zones, whereas active methods have smaller nondetection zones but they perturb the system. In this paper, a new hybrid method is proposed to solve this problem. An over/undervoltage (passive method) has been used to initiate an undervoltage shift (active method), which changes the undervoltage shift of inverter, when the passive method cannot have a clear discrimination between islanding and other events in the system. Simulation results on MATLAB/SIMULINK show that over/undervoltage and undervoltage shifts of hybrid islanding detection method are very effective because they can determine anti-islanding condition very fast.ΔP/P>38.41% could determine anti-islanding condition within 0.04 s;ΔP/P<-24.39% could determine anti-islanding condition within 0.04 s;-24.39%≤ΔP/P≤ 38.41% could determine anti-islanding condition within 0.08 s. This method perturbed the system, only in the case of-24.39% ≤ΔP/P ≤38.41% at which the control system of inverter injected a signal of undervoltage shift as necessary to check if the occurrence condition was an islanding condition or not.

scholarly journals A Test Device for Optimize PMU-Based Islanding Detection Technology

2015 ◽  
Vol 10 (2) ◽  
Keyword(s):  
Power Systems ◽  
Power Plants ◽  
Detection Method ◽  
Detection Methods ◽  
Islanding Detection ◽  
Algorithm Optimization ◽  
Test Device ◽  
Photovoltaic Power ◽  
Detection Technology ◽  
Bulk Power

Islanding detection is a necessary function for grid connected distributed generators. Usually, islanding detection methods can be classified as two catalogues: remote detecting methods and local detecting methods. Most of them have limitation and defects when they are applied in photovoltaic power stations. Recently synchronous phasor measuring units (PMU) is proposed to be applied for islanding detecting. Although the islanding detection method is supposed to be applied for traditional bulk power systems, it is also suitable for renewable generation power plants. To do this islanding detection will be implemented on central management unit of photovoltaic power station instead of on grid-tied inverters as traditionally. In implementing, the criteria of this method and the threshold of algorithm are needed to be optimized. This paper develops a test device which can optimize PMU-based islanding detection technology to validate the proposed islanding detection method applying in PV station. Then using simulation to discuss how to set a reasonable threshold for the researched islanding detection method applied in PV stations. Finally the paper provides a platform for the algorithm optimization.

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