scholarly journals Fault Section Estimation in Radial LVDC Distribution System Using Wavelet Transform

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8486
Author(s):  
Hun-Chul Seo ◽  
Gi-Hyeon Gwon ◽  
Keon-Woo Park
Keyword(s):  
Wavelet Transform ◽  
Distributed Generation ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Rapid Development ◽  
Power Conversion ◽  
Stable Operation ◽  
Protection Method ◽  
Dc Line

The demand for low voltage DC (LVDC) distribution systems is increasing due to the rapid development of power conversion technology, the increase of DC-based digital loads, and the expansion of DC-based distributed generation (DG). For the stable operation of the LVDC distribution system, it is necessary to develop a protection method. In this paper, the fault section is estimated using wavelet transform (WT) in LVDC distribution system. The fault section is classified into a DC line and a DC bus. The characteristics of fault current at each fault section part are analyzed in simple and actual LVDC system. Based on this analysis, the algorithm for fault section estimation is proposed using the detail component after performing WT. The results of fault section estimations are verified through various simulations using EMTP and MATLAB. The fault section estimation can be utilized in the development of protection schemes in LVDC distribution system.

scholarly journals Development of New Protection Scheme in DC Microgrid Using Wavelet Transform

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 283
Author(s):  
Hun-Chul Seo
Keyword(s):  
Wavelet Transform ◽  
Low Voltage ◽  
Rapid Development ◽  
Circuit Breaker ◽  
Stable Operation ◽  
Fault Current ◽  
Pv System ◽  
Dc Microgrid ◽  
Protection Scheme ◽  
Protection Method

The demand for a low voltage direct current (LVDC) microgrid is increasing by the increase of DC-based digital loads and renewable resources and the rapid development of power electronics technology. For the stable operation of an LVDC microgrid, it is necessary to develop a protection method. In this paper, the new protection scheme considering the fault section is proposed using wavelet transform (WT) in an LVDC microgrid. The fault sections are classified into DC side of the alternating current (AC)/DC converter, DC/DC converter connected to photovoltaic (PV) system, DC line, and DC bus. The characteristics of fault current at each fault section are analyzed. Based on these analyses, the new protection scheme including the fault section estimation is proposed using WT. The proposed scheme estimates the fault section using the detail component after performing WT and sends the trip signal to each circuit breaker according to the fault section. The proposed protection scheme is verified through various simulations according to the fault region and fault current using electromagnetic transient program (EMTP)/ATPDraw and MATLAB. The simulation results show that the fault section is accurately determined, and the corresponding circuit breaker (CB) operations are performed.

scholarly journals New Protection Scheme in Loop Distribution System with Distributed Generation

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5897 ◽  
Author(s):  
Hun-Chul Seo
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Fault Location ◽  
Electromagnetic Transients ◽  
Radial Distribution System ◽  
Protection Scheme ◽  
Protection Method ◽  
Bidirectional Power Flow

Loop distribution systems are increasingly used for reasons such as increased distributed generation (DG) and increased demand for a reliable and high-quality power supply. Because the loop distribution system involves bidirectional power flow, the method for protection of the radial distribution system cannot be applied. Therefore, a protection method is proposed herein for loop distribution systems. In this study, the existence of DG is also considered. According to the proposed method, the fault point is estimated on the basis of the equivalent circuit of the distribution system. Then, the fault section is determined and separated from the distribution system. The separation of DG is determined depending on whether the frequency and voltage are maintained within the steady state ranges. The proposed method is modelled and verified using the Electromagnetic Transients Program. Simulations according to the fault location are performed and analyzed. The results show that the method accurately determines the fault section so that normal power can be supplied to the healthy sections in the distribution system.

scholarly journals Optimal Harmonic Mitigation in Distribution Systems with Inverter Based Distributed Generation

2021 ◽  
Vol 11 (2) ◽  
pp. 774 ◽  
Author(s):  
Ahmed S. Abbas ◽  
Ragab A. El-Sehiemy ◽  
Adel Abou El-Ela ◽  
Eman Salah Ali ◽  
Karar Mahmoud ◽  
...  
Keyword(s):  
Power Quality ◽  
Distributed Generation ◽  
Distribution System ◽  
Distribution Systems ◽  
Renewable Energy Sources ◽  
Harmonic Distortion ◽  
Planning Problem ◽  
Voltage Profile ◽  
Harmonic Mitigation ◽  
The Impact

In recent years, with the widespread use of non-linear loads power electronic devices associated with the penetration of various renewable energy sources, the distribution system is highly affected by harmonic distortion caused by these sources. Moreover, the inverter-based distributed generation units (DGs) (e.g., photovoltaic (PV) and wind turbine) that are integrated into the distribution systems, are considered as significant harmonic sources of severe harmful effects on the system power quality. To solve these issues, this paper proposes a harmonic mitigation method for improving the power quality problems in distribution systems. Specifically, the proposed optimal planning of the single tuned harmonic filters (STFs) in the presence of inverter-based DGs is developed by the recent Water Cycle Algorithm (WCA). The objectives of this planning problem aim to minimize the total harmonic distortion (THD), power loss, filter investment cost, and improvement of voltage profile considering different constraints to meet the IEEE 519 standard. Further, the impact of the inverter-based DGs on the system harmonics is studied. Two cases are considered to find the effect of the DGs harmonic spectrum on the system distortion and filter planning. The proposed method is tested on the IEEE 69-bus distribution system. The effectiveness of the proposed planning model is demonstrated where significant reductions in the harmonic distortion are accomplished.

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.

Protection of Active Distribution Systems with DGs

2015 ◽  
Vol 16 (5) ◽  
pp. 399-411 ◽  
Author(s):  
Abdelrahman Ahmed Akila ◽  
Ahmed Helal ◽  
Hussein Eldesouki
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Distribution Systems ◽  
Distribution Network ◽  
Single Source ◽  
Passive Systems ◽  
Coordination Problem ◽  
Distributed Generators ◽  
Fault Currents ◽  
Negative Impacts

Abstract Distribution systems are traditionally designed as radial passive systems fed from a single source. Protection coordination of such systems has been easily established assuming the system radiality. Insertion of distributed generators (DGs) into distribution systems makes the distribution system to be more active which causes redistribution of fault currents magnitudes and directions. This causes negative impacts on the original protection system coordination, since the distribution system losses its radiality and passiveness. Recently protection coordination in the presence of distributed generation has been paid a great attention. Researchers proposed various solutions to solve the protection coordination problem caused by adding DG into the distribution network. In this paper, the proposed solutions for the protection coordination problem considering the DG insertion will be illustrated, classified, and criticized.

scholarly journals Reliability worth Assessment of Active Distribution System Considering Protective Devices and Multiple Distributed Generation Units

2018 ◽  
Vol 7 (2) ◽  
pp. 111
Author(s):  
Subramanya Sarma S ◽  
V. Madhusudhan ◽  
V. Ganesh
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Distribution Systems ◽  
Renewable Energy Sources ◽  
Distribution Networks ◽  
Research Area ◽  
Test System ◽  
Primary Concern ◽  
Reliability Indices ◽  
New Research

<p>Reliability worth assessment is a primary concern in planning and designing of electrical distribution systems those operate in an economic manner with minimal interruption of electric supply to customer loads. Renewable energy sources (RES) based Distributed Generation (DG) units can be forecasted to penetrate in distribution networks due to advancement in their technology. The assessment of reliability worth of DG enhanced distribution networks is a relatively new research area. This paper proposes a methodology that can be used to analyze the reliability of active distribution systems (DG enhanced distribution system) and can be applied in preliminary planning studies to compute the reliability indices and statistics. The reliability assessment in this work is carried out with analytical approach applied on a test system and simulated results validate that installation of distributed generators can improve the distribution system reliability considerably.</p>

scholarly journals Recloser-Fuse settings in distribution systems with optimizing multiple distributed generation considering technical aspects

2020 ◽  
Vol 17 (3) ◽  
pp. 1135
Author(s):  
Ahmed Mohamed Abdelbaset ◽  
AboulFotouh A. Mohamed ◽  
Essam Abou El-Zahab ◽  
M. A. Moustafa Hassan
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Power Loss ◽  
Distribution Systems ◽  
Test System ◽  
Optimal Size ◽  
Loss Reduction ◽  
Voltage Profile ◽  
Power Loss Reduction ◽  
System Power

<p><span>With the widespread of using distributed generation, the connection of DGs in the distribution system causes miscoordination between protective devices. This paper introduces the problems associated with recloser fuse miscoordination (RFM) in the presence of single and multiple DG in a radial distribution system. Two Multi objective optimization problems are presented. The first is based on technical impacts to determine the optimal size and location of DG considering system power loss reduction and enhancement the voltage profile with a certain constraints and the second is used for minimizing the operating time of all fuses and recloser with obtaining the optimum settings of fuse recloser coordination characteristics. Whale Optimizer algorithm (WOA) emulated RFM as an optimization problem. The performance of the proposed methodology is applied to the standard IEEE 33 node test system. The results show the robustness of the proposed algorithm for solving the RFM problem with achieving system power loss reduction and voltage profile enhancement.</span></p>

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 Impacts of Photovoltaic Distributed Generation Location and Size on Distribution Power System Network

2018 ◽  
Vol 9 (2) ◽  
pp. 905 ◽  
Author(s):  
N. Md. Saad ◽  
M. Z. Sujod ◽  
Lee Hui Ming ◽  
M. F. Abas ◽  
M. S. Jadin ◽  
...  
Keyword(s):  
Power Systems ◽  
Distributed Generation ◽  
Distribution System ◽  
Short Circuit ◽  
Rapid Development ◽  
Reducing Power ◽  
Load Flow ◽  
Voltage Profile ◽  
Power Losses ◽  
Distribution Grid

As the rapid development of photovoltaic (PV) technology in recent years with the growth of electricity demand, integration of photovoltaic distributed generation (PVDG) to the distribution system is emerging to fulfil the demand. There are benefits and drawbacks to the distribution system due to the penetration of PVDG. This paper discussed and investigated the impacts of PVDG location and size on distribution power systems. The medium voltage distribution network is connected to the grid with the load being supplied by PVDG. Load flow and short circuit calculation are analyzed by using DigSILENT Power Factory Software. Comparisons have been made between the typical distribution system and the distribution system with the penetration of PVDG. Impacts in which PVDG location and size integrates with distribution system are investigated with the results given from the load flow and short circuit analysis. The results indicate positive impacts on the system interconnected with PVDG such as improving voltage profile, reducing power losses, releasing transmission and distribution grid capacity. It also shows that optimal locations and sizes of DGs are needed to minimize the system’s power losses. On the other hand, it shows that PVDG interconnection to the system can cause reverse power flow at improper DG size and location and increases short circuit level.

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