Islanding Detection Scheme for Inverter-Based Distributed Generation Systems Using Cumulative Reactive Power Harmonics

2019 ◽  
Vol 14 (5) ◽  
pp. 1907-1917
Author(s):  
Raza Haider ◽  
Teymoor Ghanbari ◽  
Chul-Hwan Kim
2021 ◽  
Author(s):  
Sasan Mostafaei

This thesis presents a novel active anti-islanding detection scheme for the three phase gridconnected converters. The proposed hybrid method works based on the combination of Positive Feedback Frequency Shift (PFFS) and Reactive Power Variation (RPV) methods, and therefore it combines the features of both methods. Unlike the RPV scheme, this method is capable of synchronizing all power converters with each other in a distributed generation (DG) system. Therefore, it can effectively detect islanding when the DG system has multiple renewable energy sources interfaced to the system by multiple converters. The proposed method can also be combined with other active methods, such as the active frequency drift method. This minimizes the power quality degradation since the scheme is called upon only when 0.1Hz deviation in the grid frequency is detected. Moreover, unlike other positive feedback methods, this scheme has little impact on the stability of the DG system, since the positive feedback reference is only limited to


2021 ◽  
Author(s):  
Sasan Mostafaei

This thesis presents a novel active anti-islanding detection scheme for the three phase gridconnected converters. The proposed hybrid method works based on the combination of Positive Feedback Frequency Shift (PFFS) and Reactive Power Variation (RPV) methods, and therefore it combines the features of both methods. Unlike the RPV scheme, this method is capable of synchronizing all power converters with each other in a distributed generation (DG) system. Therefore, it can effectively detect islanding when the DG system has multiple renewable energy sources interfaced to the system by multiple converters. The proposed method can also be combined with other active methods, such as the active frequency drift method. This minimizes the power quality degradation since the scheme is called upon only when 0.1Hz deviation in the grid frequency is detected. Moreover, unlike other positive feedback methods, this scheme has little impact on the stability of the DG system, since the positive feedback reference is only limited to


Author(s):  
Bineeta Soreng ◽  
Raseswari Pradhan

In this paper, an optimal controller-based islanding detection scheme is proposed for an inverter-based distributed generation system (DGS). Islanding is both harmful and unsafe but unavoidable state in a DGS. Therefore, islanding state is required to be detected quickly and accurately. A reactive power control strategy for islanding is presented in this work. It is reported that the active and reactive power mismatches in a DGS forces its voltage or frequency to deviate. That deviation is recorded continuously in this scheme and islanding state is reported when the deviation touches the thresholds. To help in this tracking process, a modified H8-based optimal controller whose parameters are tuned with LMI is proposed. It can offer both feedback and feed-forward control actions. The proposed DGS is modelled using MATLAB/SIMULINK and tested taking several case studies. It is found that, islanding condition is rapidly detected compared to that of the uncontrolled scheme yielding an optimal solution. Further, it is an inexpensive, robust, compact in structure and very easy to implement too.


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>


Author(s):  
Bhatraj Anudeep ◽  
Paresh Kumar Nayak

Abstract In distributed generation (DG) systems, the rate of change of voltage and the rate of change of frequency are the two most common and widely used simple and low-cost passive islanding detection schemes. Unfortunately, these passive islanding detection schemes find limitation for detecting the islandings that cause very small power imbalance. In this paper, an improved passive islanding detection scheme is proposed by using the two newly derived indices from the sequence components of the current signal with the conventional voltage and frequency parameters. The performance of the proposed scheme is tested for numerous islanding and non-islanding cases generated on IEEE Std 399–1997 and IEC microgrid model distribution system integrated with both inverter-interfaced and synchronous DGs through PSCAD/EMTDC. The obtained results confirm the effectiveness of the proposed scheme.


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