scholarly journals Methods for protecting network from islanding danger

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Yasser Ahmed Elshrief ◽  
◽  
Sameh Abd-Elhaleem ◽  
Belal Ahmed Abozalam ◽  
A.D. Asham ◽  
...  
Keyword(s):  
Distributed Generator ◽  
Safety Issues ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
Utility Grid ◽  
Nondetection Zone ◽  
Detection Speed

The process of energizing loads from other sources like a distributed generator with a total disconnection of utility grid at the point of common coupling is called islanding. The islanding phenomenon affects the network by safety issues and bad impact on the utility and connected loads, especially the workers on the utility. Hence, it must be detected by a suitable anti-islanding (AI) technique which is needed to be faster in terms of time detection and smaller or negligible nondetection zone. To detect this phenomenon, there are local and remote AI techniques. In this paper, local AI techniques are illustrated, which are used for improving the performance regarding the size of the nondetection zone and detection speed.

scholarly journals An improved islanding detection algorithm based on AFDPF

2021 ◽  
Vol 257 ◽  
pp. 02049
Author(s):  
Lulu Ma ◽  
Xiujuan Guo ◽  
Liming Wei
Keyword(s):  
Power Generation ◽  
Adverse Effects ◽  
Detection Algorithm ◽  
Islanding Detection ◽  
The Third ◽  
Distributed Power Generation ◽  
Simulink Simulation ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
Nondetection Zone

Unplanned islanding is a harmful phenomenon that will cause a series of adverse effects on the power grid. Therefore, islanding detection is a necessary feature of a microgrid with distributed power generation. Based on the Active Frequency Drift with Positive Feedback (AFDPF) algorithm, this paper proposes an improved frequency offset method.The method uses the frequency difference between two cycles to determine the direction of the disturbance signal. The value of the third power is superimposed on the point of common coupling (PCC)to improve detection speed.And check the Nondetection zone of this method based on the Qf0×Cnom coordinate system. Finally, through MATLAB/simulink simulation, the effectiveness and superiority of the improved frequency shift islanding detection algorithm are verified.

DSP - Based Islanding Protection for Photovoltaic Grid Connected Inverter

2013 ◽  
Vol 291-294 ◽  
pp. 2007-2010
Author(s):  
Khanchai Tunlasakun
Keyword(s):  
Digital Signal Processor ◽  
Digital Signal ◽  
Local Load ◽  
Grid Voltage ◽  
National Instrument ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
Utility Grid ◽  
Grid Connected Inverter ◽  
Signal Processor

This research presents the DSP - based islanding protection for photovoltaic grid connected inverter with under / over frequency and under / over voltage islanding protection methods. The design is based on the TMS320VC33PGE digital signal processor on the NI SPEEDY 33 board from National Instrument Inc. The prototype is monitor the grid frequency and grid voltage at the point of common coupling (PCC) between the photovoltaic grid connected inverter, the local load and the distribution. The results of study, the prototype can turn off relay between photovoltaic grid connected inverter and utility grid when the frequency is change under 48Hz or over 52Hz and the voltage is change under 200V or over 240V.

scholarly journals Improving Voltage Profile of Islanded Microgrid using PI Controller

2018 ◽  
Vol 8 (3) ◽  
pp. 1383 ◽  
Author(s):  
Sajid Hussain Qazi ◽  
Mohd Wazir Mustafa
Keyword(s):  
Pulse Generator ◽  
Operating Mode ◽  
Pi Controller ◽  
Voltage Profile ◽  
Distributed Generator ◽  
Distributed Generators ◽  
Voltage Controller ◽  
Point Of Common Coupling ◽  
Simulation Results ◽  
Common Coupling

<p class="MsoNormal" style="margin-top: 6.0pt; text-align: justify;">In islanding operating mode of microgrid, the voltage and frequency of system must be maintained by the microgrid, or else the system will crumble due to the characteristics of different distributed generators (DG) utilized in microgrid. The voltage and frequency lost provision when main grid is disconnected. This paper presents PI controller based voltage controller to regulate voltage to its normal condition. The controller is proposed to be utilized individually with each distributed generator (DG) in microgrid. The controller compares inverter output voltage with voltage at point of common coupling (PCC) and its output is feed to PWM pulse generator to generate appropriate pulses for inverter to regulate voltage to its nominal value. The simulation results of proposed system are shown using MATLAB/Simulink platform.</p>

scholarly journals On active anti-islanding techniques: survey

2021 ◽  
Vol 22 (2) ◽  
pp. 609
Author(s):  
Yasser Ahmed Elshrief ◽  
Sameh Abd-Elhaleem ◽  
Belal Abo Zalam ◽  
Amin D. Asham
Keyword(s):  
Power Grid ◽  
Electric Utility ◽  
Islanding Detection ◽  
Detection Zone ◽  
Distributed Generators ◽  
Point Of Common Coupling ◽  
Comprehensive Survey ◽  
Common Coupling ◽  
Detection Speed ◽  
Critical Aspects

The phenomenon of feeding loads from any distributed generators (DGs) with a total disconnection of utility grid at the point of common coupling is called Islanding. The DGs are usually independently controlled. Hence, when the islanding problem occurs, the electric utility loses the control and supervision over that section of the power grid. Furthermore, prolonged islanding can prevent reconnection to the power grid and may cause damage due to voltage and frequency excursions. Therefore, the islanding detection, which is also called anti-islanding (AI), is one of the most critical aspects of the integration of DG sources into the power grid. In this paper, a<strong> </strong>comprehensive survey on the local AI techniques is illustrated, especially active type which is used for improving the performance regarding the size of the non-detection zone and detection speed. Extensive comparisons are provided to demonstrate the effectiveness of each technique.

scholarly journals A Proposed Harmonic Monitoring System for Large Power Users Considering Harmonic Limits

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4507
Author(s):  
Rosalia Sinvula ◽  
Khaled Mohamed Abo-Al-Ez ◽  
Mohamed Tariq Kahn
Keyword(s):  
Monitoring System ◽  
Renewable Energy Sources ◽  
Electronic Devices ◽  
Harmonic Distortion ◽  
Large Power ◽  
High Penetration ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
Power Utilities ◽  
The Individual

Most power utilities within Southern Africa are faced with the challenges of harmonic distortion due to the high penetration of renewable energy sources (RES) and the use of electronic devices. There is an excessive total harmonic distortion (THD) measured at the point of common coupling (PCC). In this paper, a proposed harmonic monitoring system for large power users (LPUs) is developed. This proposed system considers harmonic limits of the individual and THD of the customers allowed injecting into the network, which should be part of the contractual electricity supply agreement (ESA). Hence, it will enable the monitoring of harmonic distortion to be smooth by determining whether the customer has passed or failed compliance for individual harmonic order and the THD of the voltage. The measurements of harmonic distortion are done using the Unipower power quality (PQ) analyzers that are connected at different points within the industrial network. Measurements of harmonic distortion of an industrial site are compared to the simulation results performed by DIgSILENT software to validate the proposed harmonic monitoring system. Based on the validation results, it is recommended that the ESA between the power utilities and the customers should consist of the harmonic limits.

Assessment of power quality parameters and indicators at the point of common coupling in a low voltage power grid with photovoltaic generation emulated

2022 ◽  
Vol 203 ◽  
pp. 107679
Author(s):  
Oscar Pinzón-Quintero ◽  
Daniel Gaviria-Ospina ◽  
Alejandro Parrado-Duque ◽  
Rusber Rodríguez-Velásquez ◽  
German Osma-Pinto
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Power Grid ◽  
Quality Parameters ◽  
Photovoltaic Generation ◽  
Point Of Common Coupling ◽  
Common Coupling

Power Quality Assessment and Enhancement in a Grid Connected Renewable Energy System Using Dynamic Voltage Restorer

2014 ◽  
Vol 573 ◽  
pp. 716-721
Author(s):  
S. Rajeshbabu ◽  
B.V. Manikandan
Keyword(s):  
Neural Network ◽  
Renewable Energy ◽  
Power Quality ◽  
Energy System ◽  
Dynamic Voltage Restorer ◽  
Renewable Energy System ◽  
Voltage Restorer ◽  
Point Of Common Coupling ◽  
Dynamic Voltage ◽  
Common Coupling

Renewable energy sources provide the additional/satisfy the power to the consumer through power electronics interfaces and integrated with the grid. In grid integration power quality is one of the important parameter that need to be paying more attention. This proposed work focuses on power quality issues in a grid connected renewable energy system. Power quality issues will arises due to many factors here with the by introducing a fault condition in a grid connected renewable energy system the measurements were made at the point of common coupling and the mitigation is done with the help of a dynamic voltage restorer. The dynamic voltage restorer is a device which offers series compensation activated by neural network based controller. The sag improvement and the total harmonic assessment were made at the point of common coupling. Keywords: Neural network, Point of common coupling, Renewable energy source, Power quality, Dynamic voltage restorer ,electric grid.

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