scholarly journals A Nondestructive Islanding Detection Method Based on Adaptive and Periodic Disturbance on Reactive Power Output of Inverter-Based Distributed Generation

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaolong Chen ◽  
Yongli Li
Keyword(s):  
Distributed Generation ◽  
Power Output ◽  
Reactive Power ◽  
Detection Method ◽  
Test System ◽  
Rate Of Change ◽  
Islanding Detection ◽  
Unity Power Factor ◽  
Periodic Disturbance ◽  
Strategy Transformation

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.

scholarly journals Improved ROCOF relay for islanding detection of solar distributed generation

2019 ◽  
Vol 14 (3) ◽  
pp. 1105 ◽  
Author(s):  
J. Rajesh Reddy ◽  
A. Pandian
Keyword(s):  
Distributed Generation ◽  
Fossil Fuels ◽  
Reactive Power ◽  
Rate Of Change ◽  
Islanding Detection ◽  
Detection Zone ◽  
Detection Scheme ◽  
Renewable Distributed Generation ◽  
Power Injection ◽  
Effective Performance

<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>

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 An Islanding Detection Technique for Inverter-Based Distributed Generation in Microgrids

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 130
Author(s):  
Mazaher Karimi ◽  
Mohammad Farshad ◽  
Qiteng Hong ◽  
Hannu Laaksonen ◽  
Kimmo Kauhaniemi
Keyword(s):  
Distributed Generation ◽  
Phasor Measurement Units ◽  
Rate Of Change ◽  
Detection Technique ◽  
Islanding Detection ◽  
Simulation Studies ◽  
Local Measurements ◽  
Measurement Units ◽  
Utility Grid ◽  
Frequency Fluctuations

This article proposes a new passive islanding detection technique for inverter-based distributed generation (DG) in microgrids based on local synchrophasor measurements. The proposed method utilizes the voltage and current phasors measured at the DG connection point (point of connection, PoC). In this paper, the rate of change of voltages and the ratio of the voltage and current magnitudes (VoI index) at the PoC are monitored using micro-phasor measurement units. The developed local measurements based decentralized islanding detection technique is based on the VoI index in order to detect any kind of utility grid frequency fluctuations or oscillations and distinguishing them from islanding condition. The simulation studies confirm that the proposed scheme is accurate, robust, fast, and simple to implement for inverter-based DGs.

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.

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