scholarly journals Electrical grid reliability assessment by fault tree analysis

2020 ◽  
Vol 17 (3) ◽  
pp. 1127
Author(s):  
Ahmed Agwa ◽  
Zaky Matter ◽  
Ezzat Eisawy ◽  
Hamdy Hassan
Keyword(s):  
Fault Tree ◽  
Flow Analysis ◽  
Reliability Assessment ◽  
Fault Tree Analysis ◽  
Electrical Energy ◽  
Load Flow ◽  
System Planning ◽  
Electrical Grid ◽  
Load Flow Analysis ◽  
Planning And Operation

<p>The main rule of an electrical grid is to supply electrical energy to consumers as economically as possible, and with an adequate degree of reliability. Reliability is an essential measure and important component of all power system planning and operation procedures. In this paper, the electrical grid reliability is evaluated by Fault Tree (FT) analysis. In this method Alternating Current (AC) load flow analysis is combined with the FT technique. The electrical grid reliability is calculated based on the unreliability of the power supplied to the loads. The verification of the method is performed on a part of the Egyptian electrical grid (Alexandria zone 17-bus). The electrical grid components are sorted according to their influence on the electrical grid reliability.</p>

scholarly journals Modelling and Validation of a Grid-Connected DFIG by Exploiting the Frequency-Domain Harmonic Analysis

2020 ◽  
Vol 10 (24) ◽  
pp. 9014
Author(s):  
Emmanuel Hernández-Mayoral ◽  
Reynaldo Iracheta-Cortez ◽  
Vincent Lecheppe ◽  
Oscar Alfredo Jaramillo Salgado
Keyword(s):  
Pulse Width Modulation ◽  
Flow Analysis ◽  
Power Converter ◽  
Load Flow ◽  
Operating Conditions ◽  
Electrical Grid ◽  
Wind Energy Conversion Systems ◽  
Load Flow Analysis ◽  
Energy Conversion Systems ◽  
Doubly Fed

Wind Energy Conversion Systems (WECS) based on a Doubly-Fed Induction Generator (DFIG) represent the most common configuration employed in wind turbines. These systems involve injecting harmonic currents toward an electrical grid from a back-to-back power converter, potentially creating voltage distortions. To assess this phenomenon, a case study of a 3 kW DFIG-based wind turbine connected to the electrical grid is presented for analysis in the harmonic domain. Initially, a DFIG-based load flow analysis for determining the operating conditions is tackled at the fundamental frequency. Then, the modelling of a DFIG under steady-state operating conditions at harmonic frequencies is analyzed discussing its characteristics in the harmonic domain. The high-frequency harmonics in the output voltage of a pulse width modulation-driven inverter feeding the rotor windings of a DFIG and its connection to a three-winding transformer are also analyzed. This investigation produced a complete model of the DFIG connected to the electrical grid. The results demonstrated that although a considerable harmonic contribution up to the 25th order exists, it remains harmless since it is below 5%, according to the Std. IEEE 519.

scholarly journals Modeling and Load Flow Analysis of a Microgrid Laboratory.

2019 ◽  
Vol 3 (2) ◽  
pp. 103-111
Author(s):  
Taufik ◽  
Matthew A. Guevara ◽  
Ali Shaban ◽  
Ahmad Nafisi
Keyword(s):  
Renewable Energy ◽  
Hardware Implementation ◽  
Flow Analysis ◽  
Load Flow ◽  
Electric Power System ◽  
State University ◽  
Electrical Grid ◽  
Load Flow Analysis ◽  
Simulation Results ◽  
Hardware Test

Microgrids-miniature versions of the electrical grid are becoming increasingly more popular as advancements in technologies, renewable energy mandates, and decreased costs drive communities to adopt them. The modern microgrid has capabilities of generating, distributing, and regulating the flow of electricity, capable of operating in both grid-connected and islanded (disconnected) conditions. This paper utilizes ETAP software in the analysis, simulation, and development of a lab-scale microgrid located at Cal Poly State University. Microprocessor-based relays are heavily utilized in both the ETAP model and hardware implementation of the system. Three case studies were studied and simulated to investigate electric power system load flow analysis of the Cal Poly microgrid. Results were compared against hardware test measurements and showed overall agreement. Slight discrepancies were observed in the simulation results due mainly to the non-ideality of actual hardware components and lab equipment.

scholarly journals Probabilistic Load Flow Algorithm of Distribution Networks with Distributed Generators and Electric Vehicles Integration

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4234 ◽  
Author(s):  
Zhou ◽  
Yang ◽  
Yang ◽  
Yang ◽  
Littler ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Energy Distribution ◽  
Flow Analysis ◽  
Electrical Energy ◽  
Distribution Networks ◽  
Load Flow ◽  
Probabilistic Load Flow ◽  
Load Flow Analysis ◽  
Distributed Generators ◽  
Probabilistic Load

Probabilistic Load Flow (PLF) calculations are important tools for analysis of the steady-state operation of electrical energy networks, especially for electrical energy distribution networks with large-scale distributed generators (DGs) and electric vehicle (EV) integration. Traditional PLF has used the Cumulant Method (CM) and Latin Hypercube Sampling (LHS) method. However, traditional CM requires that each input variable be independent of one another, and the Cholesky decomposition adopted by the traditional LHS has limitations in that it is only applicable for positive definite matrices. To solve these problems, taking into account the Q-MCS theory of LHS, this paper proposes a CM PLF algorithm based on improved LHS (ILHS-CM). The cumulants of the input variables are obtained based on sampling results. The probability distribution of the output variables is obtained according to the Gram-Charlier series expansion. Moreover, DGs, such as wind turbines, photovoltaic (PV) arrays, and EVs integrated into the electrical energy distribution networks are comprehensively considered, including correlation analysis and dynamic load flow analysis for EV-coordinated charging. Four scenarios are analyzed based on the IEEE-30 node network, including with/without DGs and EVs, error analysis and performance evaluation of the proposed algorithm, correlation analysis of DGs and EVs, and dynamic load flow analysis with EV integration. The results presented in this paper demonstrate the effectiveness, accuracy, and practicability of the proposed algorithm.

Operation Characteristics of Zone 3 Distance Protection in Wind Power Systems with Fixed-Speed Induction Generators

2011 ◽  
Vol 12 (4) ◽  
Author(s):  
Shenghu Li
Keyword(s):  
Power Systems ◽  
Wind Power ◽  
Reactive Power ◽  
Flow Analysis ◽  
Load Flow ◽  
Synchronous Generators ◽  
Induction Generators ◽  
Load Flow Analysis ◽  
Wind Power Systems ◽  
Operation Characteristics

The induction generators (IGs) are basic to wind energy conversion. They produce the active power and consume the reactive power, with the voltage characteristics fragile compared with that of the synchronous generators and doubly-fed IGs. In the stressed system states, they may intensify var imbalance, yielding undesirable operation of zone 3 impedance relays.In this paper, the operation characteristics of the zone 3 relays in the wind power systems is studied. With the theoretical and load flow analysis, it is proved that the equivalent impedance of the IGs lies in the 2nd quadrature, possibly seen as the backward faults by the mho relays, i.e. the apparent impedance enters into the protection region from the left side. The undesirable operation may be caused by more wind power, larger load, less var compensation, and larger torque angle.

Load Flow Analysis for Micro Grid

2021 ◽  
pp. 177-196
Author(s):  
P. Sivaraman ◽  
C. Sharmeela ◽  
S. Elango
Keyword(s):  
Flow Analysis ◽  
Load Flow ◽  
Load Flow Analysis ◽  
Micro Grid
Sign in / Sign up

Export Citation Format

Share Document