scholarly journals Assessing and Mitigating Impacts of Electric Vehicle Harmonic Currents on Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3257
Author(s):  
Dima Alame ◽  
Maher Azzouz ◽  
Narayan Kar
Keyword(s):  
Electric Vehicle ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Weighted Arithmetic ◽  
Harmonic Currents ◽  
Distribution Transformers ◽  
Voltage Quality ◽  
Harmonic Power

Harmonic currents of electric vehicle (EV) chargers could jeopardize the power quality of distribution systems and add to the transformer’s losses, thus degrading its lifetime. This paper assesses and mitigates the impacts of different EV chargers on distribution transformers and the voltage quality of distribution systems. The effect of state-of-charge (SOC) of the EV battery is considered through applying weighted arithmetic mean to accurately assess the impacts of EV harmonic currents on aging and losses of the EV interfacing transformer. The voltage quality of the IEEE 33-bus distribution system, supplying several EV parking lots, is also assessed at different charging levels using a fast-decoupled harmonic power flow. A new optimal harmonic power flow algorithm—that incorporates photovoltaic-based distribution generation units (DGs)—is developed to enhance the voltage quality of distribution systems, and elongate the lifetime of the substation transformer. The effectiveness of the proposed mitigation method is confirmed using the IEEE 33-bus distribution system, hosting several EV charging stations and photovoltaic-based DGs.

scholarly journals An Optimal Phase Arrangement of Distribution Transformers under Risk Assessment

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5852
Author(s):  
Chia-Sheng Tu ◽  
Chung-Yuen Yang ◽  
Ming-Tang Tsai
Keyword(s):  
Distribution System ◽  
Value At Risk ◽  
Power Flow ◽  
Distribution Systems ◽  
Operating Efficiency ◽  
Voltage Profile ◽  
Distribution Transformers ◽  
Line Loss ◽  
Load Arrangement ◽  
Phase Arrangement

This paper presents a phase arrangement procedure for distribution transformers to improve system unbalance and voltage profile of distribution systems, while considering the location and uncertainties of the wind turbine (WT) and photovoltaics (PV). Based on historical data, the Monte Carlo method is used to calculate the power generation value-at-risk (VAR) of WTs/PVs installed under a given level of confidence. The main target of this paper is to reduce the line loss and unbalance factor during 24-hour intervals. Assessing the various confidence levels of risk, a feasible particle swarm optimization (FPSO) is proposed to solve the optimal location of WTs/PVs installed and transformer load arrangement. A three-phase power flow with equivalent current injection (ECI) is analyzed to demonstrate the operating efficiency of the FPSO in a Taipower feeder. Simulation results will support the planner in the proper location of WTs/PVs installed to reduce system losses and maintain the voltage profile. They can also provide more risk information for handing uncertainties when the renewable energy is connected to the distribution system.

scholarly journals Protection of Sensitive Loads in Distribution Systems Using a BSFCL-DVR System

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1615
Author(s):  
Mehdi Firouzi ◽  
Saleh Mobayen ◽  
Hossein Shahbabaei Kartijkolaie ◽  
Mojtaba Nasiri ◽  
Chih-Chiang Chen
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Fault Current ◽  
Dynamic Voltage Restorer ◽  
Voltage Quality ◽  
Voltage Restorer ◽  
Point Of Common Coupling ◽  
Dynamic Voltage ◽  
Bridge Type ◽  
In The Beginning

In this paper, an incorporated bridge-type superconducting fault current limiter (BSFCL) and Dynamic Voltage Restorer (DVR) is presented to improve the voltage quality and limiting fault current problems in distribution systems. In order to achieve these capabilities, the BSFCL and DVR are integrated through a common DC link as a BSFCL-DVR system. The FCL and DVR ports of the BSFCL-DVR system are located in the beginning and end of the sensitive loads’ feeder integrated to the point of common coupling (PCC) in the distribution system. At first, the principle operation of the BSFCL-DVR is discussed. Then, a control system for the BSFCL-DVR system is designed to enhance the voltage quality and limit the fault current. Eventually, the efficiency of the BSFCL-DVR system is verified through the PSCAD/EMTDC simulation.

scholarly journals A Head Formulation for the Steady-State Analysis of Water Distribution Systems Using an Explicit and Exact Expression of the Colebrook–White Equation

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1163
Author(s):  
Mengning Qiu ◽  
Avi Ostfeld
Keyword(s):  
Steady State ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Solution Method ◽  
Water Distribution System ◽  
Academic Research ◽  
Exact Expression ◽  
Contamination Source

Steady-state demand-driven water distribution system (WDS) solution is the bedrock for much research conducted in the field related to WDSs. WDSs are modeled using the Darcy–Weisbach equation with the Swamee–Jain equation. However, the Swamee–Jain equation approximates the Colebrook–White equation, errors of which are within 1% for ϵ/D∈[10−6,10−2] and Re∈[5000,108]. A formulation is presented for the solution of WDSs using the Colebrook–White equation. The correctness and efficacy of the head formulation have been demonstrated by applying it to six WDSs with the number of pipes ranges from 454 to 157,044 and the number of nodes ranges from 443 to 150,630. The addition of a physically and fundamentally more accurate WDS solution method can improve the quality of the results achieved in both academic research and industrial application, such as contamination source identification, water hammer analysis, WDS network calibration, sensor placement, and least-cost design and operation of WDSs.

scholarly journals Smart charging for electric vehicles to minimise charging cost

2017 ◽  
Vol 231 (6) ◽  
pp. 526-534 ◽  
Author(s):  
Yue Wang ◽  
David Infield ◽  
Simon Gill
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Distribution System ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Low Voltage ◽  
Wholesale Price ◽  
Heuristic Method ◽  
Domain Model ◽  
Smart Charging

This paper assumes a smart grid framework where the driving patterns for electric vehicles are known, time variations in electricity prices are communicated to householders, and data on voltage variation throughout the distribution system are available. Based on this information, an aggregator with access to this data can be employed to minimise electric vehicles charging costs to the owner whilst maintaining acceptable distribution system voltages. In this study, electric vehicle charging is assumed to take place only in the home. A single-phase Low Voltage (LV) distribution network is investigated where the local electric vehicles penetration level is assumed to be 100%. Electric vehicle use patterns have been extracted from the UK Time of Use Survey data with a 10-min resolution and the domestic base load is generated from an existing public domain model. Apart from the so-called real time price signal, which is derived from the electricity system wholesale price, the cost of battery degradation is also considered in the optimal scheduling of electric vehicles charging. A simple and effective heuristic method is proposed to minimise the electric vehicles’ charging cost whilst satisfying the requirement of state of charge for the electric vehicles’ battery. A simulation in OpenDSS over a period of 24 h has been implemented, taking care of the network constraints for voltage level at the customer connection points. The optimisation results are compared with those obtained using dynamic optimal power flow.

Optimal Capacitors Placement of Distribution Systems Using 2nd Order Power Loss Sensitivity Analysis and Hierarchical Clustering

2014 ◽  
Vol 986-987 ◽  
pp. 377-382 ◽  
Author(s):  
Hui Min Gao ◽  
Jian Min Zhang ◽  
Chen Xi Wu
Keyword(s):  
Sensitivity Analysis ◽  
Hierarchical Clustering ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Digital Simulation ◽  
Second Order ◽  
First Order ◽  
The Impact

Heuristic methods by first order sensitivity analysis are often used to determine location of capacitors of distribution power system. The selected nodes by first order sensitivity analysis often have virtual high by first order sensitivities, which could not obtain the optimal results. This paper presents an effective method to optimally determine the location and capacities of capacitors of distribution systems, based on an innovative approach by the second order sensitivity analysis and hierarchical clustering. The approach determines the location by the second order sensitivity analysis. Comparing with the traditional method, the new method considers the nonlinear factor of power flow equation and the impact of the latter selected compensation nodes on the previously selected compensation location. This method is tested on a 28-bus distribution system. Digital simulation results show that the reactive power optimization plan with the proposed method is more economic while maintaining the same level of effectiveness.

scholarly journals Rapid Performance Evaluation of Water Supply Services for Strategic Planning

2019 ◽  
Vol 5 (5) ◽  
pp. 1197-1204 ◽  
Author(s):  
Gulfam Shahzad ◽  
Rashid Rehan ◽  
Muhammad Fahim
Keyword(s):  
Strategic Planning ◽  
Water Supply ◽  
Distribution System ◽  
Distribution Systems ◽  
Google Earth ◽  
System A ◽  
Quality Of Water ◽  
Interactive Map ◽  
Water Supply Services

The assessment of existing water supply services was carried out through selected performance indicators with the aim of using that data in future for strategic planning of urban Mardan. The key performance indictors studied were selected to assess both the quantity and quality of water. The quality of water was assessed by turbidity, pH, and E-coli tests for samples collected at the start, middle, and tail end of the distribution system. The quantity of water supplied was measured by calculating discharges from water tapes at the three selected locations in the distribution system. A total of thirty samples were collected from ten union councils out of fourteen covering urban Mardan. A number of issues are highlighted in the overall water supply infrastructure and short, mid, and long term remedial measures are recommended. The results are presented in the form of an interactive map using Google Earth and VBA based dynamic database. It was found that the overall quality of water is generally acceptable for drinking. However, the presence of bacteria is an issue in many cases which needs to be resolved. A significant decrease in discharge is observed in the distribution systems away from the source due to leakages and illegal connections. A comprehensive overhaul of both management and infrastructure is required for sustainable and satisfactory level of services.

An Approach to Voltage Quality Enhancement by Introduction of CWVM for Distribution System

2016 ◽  
Vol 7 (4) ◽  
pp. 1276
Author(s):  
Alok Kumar Shrivastav ◽  
Pradip Kumar Sadhu ◽  
Ankur Ganguly ◽  
Saumen Dhara
Keyword(s):  
Distribution System ◽  
Quality Enhancement ◽  
Steady State Response ◽  
Practical Application ◽  
Electrical Circuits ◽  
State Response ◽  
Harmonic Currents ◽  
Voltage Quality ◽  
Unbalance Voltage ◽  
Voltage Flicker

This paper presented with problems related with voltage flicker in power system networks. Several international standard issued to control the voltage flicker are briefly described and some important methods to analyse electrical circuits with sinusoidal and non-sinusoidal waveforms are introduced and evaluated. One of these methods – Cockcroft Walton Voltage Multiplier (CWVM) has been used to increase the voltage of a filter, which is also described in this paper as a practical application. The filter can compensate for harmonic currents, power factor, and unbalance voltage.<strong> </strong>The simulation results using Multisim are presented, showing that good dynamic and steady-state response can be achieved with this approach<em>.</em>

scholarly journals A Sensitivity-Based Three-Phase Weather-Dependent Power Flow Algorithm for Networks with Local Controllers—Part I: Algorithm Development

2021 ◽  
Author(s):  
Evangelos Pompodakis ◽  
Arif Ahmed ◽  
Minas Alexiadis
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
System Analysis ◽  
Distribution Networks ◽  
Theoretical Development ◽  
Modern Distribution ◽  
Three Phase ◽  
Flow Algorithm ◽  
Weather Variations

<b>Local voltage controllers (LVCs) are important components of a modern distribution system for regulating the voltage within permissible limits. This manuscript presents a sensitivity-based three-phase weather-dependent power flow algorithm for distribution networks with LVCs. This Part I presents the theoretical development of the proposed algorithm, which has four distinct characteristics: a) it considers the three-phase unbalanced nature of distribution systems, b) the operating state of LVCs is calculated using sensitivity parameters, which accelerates the convergence speed of the algorithm, c) it considers the precise switching sequence of LVCs based on their reaction time delays, and d) the nonlinear influence of weather variations in the power flow is also taken into consideration. Simulations and validation results presented in Part II indicate that the proposed approach outperforms other existing algorithms with respect to the accuracy and speed of convergence, thus making it a promising power flow tool for accurate distribution system analysis. </b><div><b><br></b></div>

scholarly journals Performance Analysis of Plug-in Electric Vehicle Supported DVR for Power-Quality Improvement and Energy Back-Up Strategy

2020 ◽  
Vol 8 (6) ◽  
pp. 945-952
Keyword(s):  
Electric Vehicle ◽  
Power Quality ◽  
Distribution System ◽  
Power Flow ◽  
Fossil Fuels ◽  
Electrical Power ◽  
Peak Load ◽  
Electrical Energy ◽  
Distribution Grid ◽  
Dynamic Voltage Restorer

Electric vehicle technology becomes increasingly important as it takes care of the environmental issues related to ICE vehicle and reduces the dependency on fossil fuels. Electric vehicle being greatly dependent on the limited electrical energy provided by a battery, the power flow efficiency is very important in this context. Electric vehicle integration to the distribution grid is increased at a faster rate because it can act as power backup to the grid/local loads reducing the peak load and filling the valley point. Most of software engineers own an Electric Vehicle based on eco-friendly principles. The Batteries in the car are connected to the charging point (or) grid monitoring of State of Charging (SOC) facilities in the parking area of company. When the Renewable power (solar energy) is available, the batteries will be charged to hundred percentage of SOC. Then excess power from PV will connect to load as well as grid. When the electrical power supply cutoff the car batteries will act as a battery bank of UPS and support to the critical load with condition based Allowable SOC. The total capacity of the batteries depends upon the no of cars available at a particular shift in a day. This work proposes the power backup of EV is utilized as an UPS to Software Company as well as used to support the Dynamic Voltage Restorer (DVR) to mitigate the fault occurring in the distribution system. Additionally, the EV supported DVR compensates voltage harmonics, voltage sag-swell, voltage interruptions coming from distribution to enhance power-quality of entire EV system without any additional compensation devices. The entire system is modeled using MATLAB/SIMULINK and the results confer the feasibility of the proposed objective.

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