scholarly journals Modeling and Estimation of Break Arc Extinction Distance in Low Voltage DC Systems

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6646
Author(s):  
Yong-Jung Kim ◽  
Hyo-Sung Kim
Keyword(s):  
Power Generation ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
System Stability ◽  
Temperature Plasma ◽  
Arc Voltage ◽  
Dc System ◽  
System A ◽  
Arc Current

Recently, as DC power generation and DC loads such as renewable energy and EVs increase, the need for a low-voltage direct current (LVDC) distribution system has gradually emerged. The DC system has various advantages, such as system stability, transmission efficiency, and connectivity to renewable power generation compared to AC distribution systems. One of the important technical issues for commercialization of DC distribution system is safety. Since the DC system does not have a current zero point, unlike the AC system, a breaking arc accompanied by a high-temperature plasma is easily generated when the circuit is cut off. The arc can cause fire accidents that threaten people and facilities. In order to prevent customers and facilities from the accidents caused by the arc in the DC system, a study on the characteristics of the DC breaking arc is necessary. An important factor of characteristics for the DC breaking arc fault is an arc extinction distance at which the DC breaking arc is completely extinguished. There are two major behaviors in DC breaking arc; one is active behavior where the arc voltage is inversely related with the arc current for a given gap distance, the other is passive behavior where the arc voltage is negatively proportional to the arc current according to Kirchhoff's voltage rule. This paper combines the two arc characteristics together to establish a DC breaking arc model, and proposes a method to estimate the arc extinction distance. Experiment results verify the method under various power and load conditions.

scholarly journals Electric Vehicles in Jordan: Challenges and Limitations

2021 ◽  
Vol 13 (6) ◽  
pp. 3199
Author(s):  
Laith Shalalfeh ◽  
Ashraf AlShalalfeh ◽  
Khaled Alkaradsheh ◽  
Mahmoud Alhamarneh ◽  
Ahmad Bashaireh
Keyword(s):  
Electric Vehicles ◽  
Distribution System ◽  
Distribution Systems ◽  
Environmental Benefits ◽  
System Stability ◽  
Loading Conditions ◽  
Stability Margins ◽  
High Penetration ◽  
Node Distribution ◽  
The Impact

An increasing number of electric vehicles (EVs) are replacing gasoline vehicles in the automobile market due to the economic and environmental benefits. The high penetration of EVs is one of the main challenges in the future smart grid. As a result of EV charging, an excessive overloading is expected in different elements of the power system, especially at the distribution level. In this paper, we evaluate the impact of EVs on the distribution system under three loading conditions (light, intermediate, and full). For each case, we estimate the maximum number of EVs that can be charged simultaneously before reaching different system limitations, including the undervoltage, overcurrent, and transformer capacity limit. Finally, we use the 19-node distribution system to study these limitations under different loading conditions. The 19-node system is one of the typical distribution systems in Jordan. Our work estimates the upper limit of the possible EV penetration before reaching the system stability margins.

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.

scholarly journals Design and Testing of a Low Voltage Solid-State Circuit Breaker for a DC Distribution System

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 338
Author(s):  
Leslie Tracy ◽  
Praveen Kumar Sekhar
Keyword(s):  
Solid State ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Circuit Breaker ◽  
Solid State Circuit ◽  
Dc Distribution ◽  
High Side ◽  
Solid State Circuit Breaker

In this study, a low voltage solid-state circuit breaker (SSCB) was implemented for a DC distribution system using commercially available components. The design process of the high-side static switch was enabled through a voltage bias. Detailed functional testing of the current sensor, high-side switch, thermal ratings, analog to digital conversion (ADC) techniques, and response times of the SSCB was evaluated. The designed SSCB was capable of low-end lighting protection applications and tested at 50 V. A 15 A continuous current rating was obtained, and the minimum response time of the SSCB was nearly 290 times faster than that of conventional AC protection methods. The SSCB was implemented to fill the gap where traditional AC protection schemes have failed. DC distribution systems are capable of extreme faults that can destroy sensitive power electronic equipment. However, continued research and development of the SSCB is helping to revolutionize the power industry and change the current power distribution methods to better utilize clean renewable energy systems.

scholarly journals Investigation of Var Compensation Schemes in Unbalanced Distribution Systems

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yinuo Huang ◽  
Licheng Wang ◽  
Kai Wang
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Current System ◽  
Voltage Regulation ◽  
Voltage Sensitivity ◽  
Compensation Methods ◽  
Distribution System Planning ◽  
Var Compensation ◽  
Phase Conductors

Distributed rooftop photovoltaic (PV) generators prospered distributed generation (DG) in recent years. Certain randomness of rooftop PV connection may lead to significant PV power imbalance across three phases, especially in low-voltage distribution systems. Due to interphase line coupling, traditional Var compensation methods which typically have competent voltage regulation performance may become less effective in such PV imbalance scenarios. In this paper, the limitation of traditional Var compensation methods in voltage regulation with unbalanced PV power integration is demonstrated and comprehensively analyzed. After describing the voltage regulation challenge, based on the voltage sensitivity analysis, it is revealed that PV power unbalanced level together with equivalent mutual impedance among phase conductors has a significant impact on the effectiveness of traditional Var compensation methods on voltage regulation. On this basis, to improve the performance of voltage regulation methods, some suggestions are proposed for both current system operation and future distribution system planning. Numerical studies demonstrate the effectiveness of the proposed suggestions. Future rooftop PV integration in LV systems can benefit from this research.

scholarly journals Research On Arc Fault Detection Using Morlet Wavelet Features And ResNet

2021 ◽  
Author(s):  
Shuai Zhang ◽  
Na Qu ◽  
Tianfang Zheng ◽  
Congqiang Hu
Keyword(s):  
Distribution System ◽  
Low Voltage ◽  
Detection System ◽  
Coefficient Matrix ◽  
Morlet Wavelet ◽  
Data Set ◽  
System A ◽  
Wavelet Features ◽  
The Time Domain ◽  
Space Image

Abstract Series arc fault is the main cause of electrical fire in low-voltage distribution system. A fast and accurate detection system can reduce the risk of fire effectively. In this paper, series arc experiment is carried out for different kinds of electrical load. The time-domain current is analyzed by Morlet wavelet. Then, the multiscale wavelet coefficients are expressed as the coefficient matrix. We use HSV color index to map the coefficient matrix to the phase space image. Random gamma transform and random rotation are applied to data enhancement. Finally, typical deep residual network (ResNet) is established for image recognition. Training results show that this method can detect faults in real time. The accuracy of ResNet50 is 96.53% by using the data set in this paper.

scholarly journals The Simulation Study of a Restructured Residential Low-Voltage Distribution System Microgrid

2016 ◽  
Vol 13 (2) ◽  
pp. 103
Author(s):  
L. Ramesh ◽  
Umamageswari Umamageswari
Keyword(s):  
Power Generation ◽  
Distribution System ◽  
Tamil Nadu ◽  
Low Voltage ◽  
Voltage Distribution ◽  
Distributed Energy ◽  
Power Sources ◽  
Electricity Grid ◽  
Renewable Power ◽  
Near Future

A primary and necessary focus in creating a greener environment is the conversion of existing power-generation sources to renewable power sources in the near future. Another important focus is to develop sustainable household power generation to a low-voltage electricity grid with a power purchase and selling facility. To help with achieving the above vision, the objective of this work is to critically analyze the existing low-voltage distribution system and make suggestions for restructuring it to the low-voltage interconnected microgrid (MG). The test was carried out in the Tamil Nadu Electricity Board (TNEB) 100kVA transformer feeder which was connected to supply around 100 houses with electricity. The performance analysis of the proposed system was examined through different case studies, represented as a normal operating condition of the existing distribution system and a reconstructed and interconnected MG to the TNEB grid. The project was designed and analyzed using PSCAD software. The results discussed in the project are helpful in examining the effects of multiple distributed energy resources on distributed generation. In future, knowledge of these effects may be helpful for rural area electrification. 

scholarly journals Performances Analysis on Power Quality Problems Mitigation by using Unified Power Quality Conditioner (UPQC)

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
May Phone Thit
Keyword(s):  
Power Quality ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Maximum Load ◽  
Dynamic Voltage Restorer ◽  
Power Distribution System ◽  
System A ◽  
Unified Power Quality Conditioner ◽  
Power Quality Conditioner

Nowadays, power quality is one of the major problems in electric power distribution system. The poor power quality at distribution level can affect the operation and performance of sensitive and critical loads. In the distribution systems, poor power quality results in various problems such as higher power losses, harmonics, sag and swells in the voltage, and poor power factor., etc. Unified Power Quality Conditioner (UPQC) is the only versatile device which can mitigate several power quality problems related with distribution system. A UPQC that combines the operations of a Distribution Static Compensator (D-STATCOM) and Dynamic Voltage Restorer (DVR) together with the shunt and series active control devices. UPQC can solve the problems related to the voltage/current harmonics, voltage sag/swell and unbalance in distribution system. To evaluate the performance improvement in the system, a model of UPQC is developed in MATLAB/SIMULINK with a typical distribution network. In this research, UPQC is applied for power quality enhancement of Myaungtagar industrial distribution substation, Myanmar. Enhancements in power quality by UPQC are evaluated under maximum load condition.Keywords—Power Quality, UPQC, Series Controller, Shunt controller, Harmonics

scholarly journals A Distributed Control Scheme Using SiC-Based Low Voltage Ride-Through Compensator for Wind Turbine Generators

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 39
Author(s):  
Chao-Tsung Ma ◽  
Zong-Hann Shi
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Distributed Control ◽  
Low Voltage ◽  
System Stability ◽  
Low Voltage Ride Through ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Control Scheme ◽  
Reactive Current

As the penetration of renewable energy power generation, such as wind power generation, increases low-voltage ride-through (LVRT), control is necessary during grid faults to support wind turbine generators (WTGs) in compensating reactive current to restore nominal grid voltages, and maintain a desired system stability. In contrast to the commonly used centralized LVRT controller, this study proposes a distributed control scheme using a LVRT compensator (LVRTC) capable of simultaneously performing reactive current compensation for doubly-fed induction generator (DFIG)-, or permanent magnet synchronous generator (PMSG)-based WTGs. The proposed LVRTC using silicon carbide (SiC)-based inverters can achieve better system efficiency, and increase system reliability. The proposed LVRTC adopts a digital control scheme and dq-axis current decoupling algorithm to realize simultaneous active/reactive power control features. Theoretical analysis, derivation of mathematical models, and design of the control scheme are initially conducted, and simulation is then performed in a computer software environment to validate the feasibility of the system. Finally, a 2 kVA small-scale hardware system with TI’s digital signal processor (DSP) as the control core is implemented for experimental verification. Results from simulation and implementation are in close agreement, and validate the feasibility and effectiveness of the proposed control scheme.

scholarly journals Investigation on Using Low Voltage Automatic Regulation to Minimize the Impacts of Charging Plug-in Electric Vehicles in Distribution Systems

2021 ◽  
Vol 19 ◽  
pp. 85-90
Author(s):  
Priscila Costa Nascimento ◽  
◽  
Michel Girotto de Oliveira ◽  
José Carlos M. Vieira
Keyword(s):  
Steady State ◽  
Electric Vehicles ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Electric Energy ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Automatic Regulation ◽  
Electric Energy Storage

The growth of micro and mini distributed generation and, more recently, the use of electric energy storage systems and the incentives for electric mobility are important examples of the transformations that distribution networks have been going through. In this context, this paper firstly presents the impacts of uncoordinated plug-in electric vehicles (PEVs) charging in a real Brazilian distribution system. Four scenarios were elaborated with different PEVs penetration levels and the results show increased voltage unbalance, system losses, and violations of the steady-state voltage limits, even in the presence of an automatic voltage regulator installed in the medium voltage network. Then, as the main contribution, the potential usage of automatic voltage regulation at the low voltage network was investigated to minimize the negative impacts of uncontrolled PEV charging on distribution system steady-state operation. It is important to highlight that this is not a common practice of utilities in Brazil. The obtained results showed that regulating the voltage at the low voltage side could be an effective solution to keep the voltages within statutory limits.

scholarly journals On the Conflict between LVRT and Line Protection in LV Distribution Systems with PVs: A Current-Limitation-Based Solution

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2909 ◽  
Author(s):  
Aristotelis Tsimtsios ◽  
Dionisis Voglitsis ◽  
Ioannis Perpinias ◽  
Christos Korkas ◽  
Nick Papanikolaou
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Energy Resource ◽  
Distribution Networks ◽  
Voltage Distribution ◽  
Current Limitation ◽  
Protection Scheme ◽  
Low Voltage Ride Through ◽  
Photovoltaic Generators

The upcoming adoption of low-voltage-ride-through requirements in low-voltage distribution systems is expected to raise significant challenges in the operation of grid-tied inverters. Typically, these inverters interconnect photovoltaic units, which are the predominant distributed energy resource in low-voltage distribution networks, under an umbrella of standards and protection schemes. As such, a challenging issue that should be considered in low-voltage distribution network applications, regards the coordination between the line protection scheme (typically consisting of a non-settable fuse) and the low-voltage-ride-through operation of photovoltaic generators. During a fault, the fuse protecting a low-voltage feeder may melt, letting the generator to continue its ride-through operation. Considering that the efficacy/speed of the anti-islanding detection is affected by ride-through requirements, this situation can lead to protracted energization of the isolated feeder after fuse melting (unintentional islanding). To address this issue, this paper proposes a fault-current-limitation based solution, which does not require any modification in the existing protection scheme. The operation principles, design, and implementation of this solution are presented, while, its effectiveness is supported by extensive simulations in a test-case low-voltage distribution system. A discussion on the presented results concludes the paper.

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