scholarly journals Voltage Estimation Method for Power Distribution Networks Using High-Precision Measurements

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2385
Author(s):  
Chan-Hyeok Oh ◽  
Seok-Il Go ◽  
Joon-Ho Choi ◽  
Seon-Ju Ahn ◽  
Sang-Yun Yun
Keyword(s):  
Case Studies ◽  
High Precision ◽  
Distribution System ◽  
Random Noise ◽  
Estimation Method ◽  
Distribution Networks ◽  
Precision Measurements ◽  
Estimation Accuracy ◽  
Bus Voltage ◽  
Load Center

In this study, we propose a voltage estimation method for the radial distribution network with distributed generators (DGs) using high-precision measurements (HPMs). The proposed method uses the section loads center for voltage estimation because individual loads are not measured in the distribution system. The bus voltage was estimated through correction of the section load center by using an HPM at the end of the main feeder. The correction parameter of the section load center was calculated by comparing the initial voltage estimates and the measurements of the HPMs. After that, the voltage of the main feeder was re-estimated. Finally, the bus voltage in the lateral feeder was estimated based on the voltage estimates in the main feeder and the current measurements in the lateral feeder. The accuracy of the proposed algorithm was verified through case studies by using test systems implemented in MATLAB, Simulink, and Python environments. In order to verify the utilization of the proposed method to the practical system, a test with injection of approximately 5% of normally distributed random noise was performed. Through the results of the case studies, when an HPM is installed at the end of the main feeder, it demonstrated that the voltage estimation accuracy can be greatly improved by the proposed method. Compared with the existing methods, the proposed method was less affected by PV and showed robustness to measurement noise.

scholarly journals Optimal Micro-PMU Placement Using Mutual Information Theory in Distribution Networks

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1917 ◽  
Author(s):  
Zhi Wu ◽  
Xiao Du ◽  
Wei Gu ◽  
Ping Ling ◽  
Jinsong Liu ◽  
...  
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Estimation Method ◽  
Distribution Networks ◽  
Point Estimation ◽  
Optimal Placement ◽  
Measurement Unit ◽  
Selection Strategy ◽  
Smart Meters ◽  
Point Estimation Method

Micro-phasor measurement unit (μPMU) is under fast development and becoming more and more important for application in future distribution networks. It is unrealistic and unaffordable to place all buses with μPMUs because of the high costs, leading to the necessity of determining optimal placement with minimal numbers of μPMUs in the distribution system. An optimal μPMU placement (OPP) based on the information entropy evaluation and node selection strategy (IENS) using greedy algorithm is presented in this paper. The uncertainties of distributed generations (DGs) and pseudo measurements are taken into consideration, and the two-point estimation method (2PEM) is utilized for solving stochastic state estimation problems. The set of buses selected by improved IENS, which can minimize the uncertainties of network and obtain system observability is considered as the optimal deployment of μPMUs. The proposed method utilizes the measurements of smart meters and pseudo measurements of load powers in the distribution systems to reduce the number of μPMUs and enhance the observability of the network. The results of the simulations prove the effectiveness of the proposed algorithm with the comparison of traditional topological methods for the OPP problem. The improved IENS method can obtain the optimal complete and incomplete μPMU placement in the distribution systems.

scholarly journals Charging Station and Power Network Planning for Integrated Electric Vehicles (EVs)

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2595 ◽  
Author(s):  
Guozhong Liu ◽  
Li Kang ◽  
Zeyu Luan ◽  
Jing Qiu ◽  
Fenglei Zheng
Keyword(s):  
Case Studies ◽  
Traffic Flow ◽  
Electric Vehicles ◽  
Distribution System ◽  
Large Scale ◽  
Distribution Networks ◽  
Fuzzy Membership Function ◽  
Multi Objective ◽  
Charging Stations ◽  
The Impact

The optimal location and size of charging stations are important considerations in relation to the large-scale application of electric vehicles (EVs). In this context, considering that charging stations are both traffic service facilities and common electric facilities, a multi-objective model is built, with the objectives of maximizing the captured traffic flow in traffic networks and minimizing the power loss in distribution networks. There are two kinds of charging stations that are considered in this paper, and the planning of EV charge stations and distribution networks is jointly modelled. The formulated multi-objective optimization problem is handled by a fuzzy membership function. The genetic algorithm (GA) is used to solve the objective function. In case studies, a 33-node distribution system and a 25-node traffic network are used to verify the effectiveness of the proposed model. The location and capacity of two kinds of charging stations are designed in the case studies, after which the impact of the battery on the captured traffic flow is analyzed as well.

scholarly journals High-Precision Mutual Coupling Coefficient Estimation for Adaptive Beamforming

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Ziang Feng ◽  
Guoping Hu ◽  
Qichao Ge ◽  
Hao Zhou
Keyword(s):  
High Precision ◽  
Coupling Coefficient ◽  
Transition Matrix ◽  
Mutual Coupling ◽  
Signal To Noise Ratio ◽  
Estimation Method ◽  
Adaptive Beamforming ◽  
Estimation Accuracy ◽  
Matrix Estimation ◽  
Coefficient Estimation

Here, a high-precision mutual coupling coefficient estimation method is proposed that is more suitable for adaptive beamforming than traditional algorithms. According to the relationship between the designed transition matrix and the signal, the proposed algorithm selects the transition matrix corresponding to the high-power signal. The high-precision estimation of the mutual coupling coefficient is obtained by using the selected transition matrix estimation, which yields relatively good estimation accuracy for the mutual coupling coefficient when the desired signal-to-noise ratio (SNR) is low and relatively robust adaptive beamforming with unknown mutual coupling. Simulation results demonstrate the validity of the proposed method.

Permormance Analysis of Distribution System with Distributed Generation, A Case Study of Nepal

2014 ◽  
Vol 472 ◽  
pp. 211-218
Author(s):  
Ku Sang Sherpa ◽  
Diwakar Bhujel ◽  
Arbinda Kumar Mishra
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Reactive Power ◽  
Distribution Networks ◽  
Electric Power System ◽  
Limiting Factor ◽  
Voltage Dip ◽  
Maximum Penetration ◽  
Voltage Limit ◽  
Bus Voltage

This paper presents analysis of impact of synchronous machine based distributed generation (DG) in distribution networks at various penetration levels. Higher DG penetration level raises important issues about distribution system operation. Therefore, new techniques are needed to determine the maximum amount of DG that may be installed without requiring major changes in the existing electric power system. In this paper, DG is placed at the terminal points of the lateral one at a time and both real and reactive power is injected at power factor ranging from unity to zero. Limiting factor for maximum penetration primarily taken is load bus voltage at upper voltage limit of 1.05 pu. Variation in substation voltage is taken as another important constraint. System under consideration for studies is the radial distribution network originating from Chaumala Substation that is situated in Kailali district of Nepal. This paper reveals that maximum allowable voltage rise perspective is recommendable if substation voltage is regulated at 1.05 pu but if substation voltage is kept at 1.00 pu, highly utopist scenario of penetration occurs. So, conductor ampacity or line loading perspective shall be suitable. Further, if DG is injected taking substation voltage at 1.05pu, there is a chance of under voltage at bus that is situated at the end of the critical branch. On contrary, if substation voltage is taken to be 1.00pu, voltage dip is severe at the bus situated very close to substation.Lastly, if the DG is placed closer to the substation, its penetration level should be increased and vice versa.

Analisis Hidrolis dan Jejak Karbon Jaringan Distribusi Air Bersih di Pulau Kecil Padat Penduduk (Pulau Lengkang Kecil, Kota Batam)

2020 ◽  
Vol 21 (2) ◽  
pp. 227-235
Author(s):  
Muhammad Rizki Apritama ◽  
I Wayan Koko Suryawan ◽  
Yosef Adicita
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Treatment Plant ◽  
Primary Source ◽  
Distribution Networks ◽  
Clean Water ◽  
Island Community ◽  
Dug Wells ◽  
Centralized Wastewater Treatment

ABSTRACTThe clean water supply system network on Lengkang Kecil Island was developed in 2019. A small portion of the community's freshwater comes from harvesting rainwater and dug wells, which are only obtained during the rainy season. The primary source of clean water used by the community comes from underwater pipelines with a daily discharge of 0.86 l/sec. The water supply of the Lengkang Kecil Island community is 74.3 m3/day, with 146 House Connections (HCs) and to serve public facilities such as elementary schools, primary health centers, and mosques. Hydraulic evaluation of clean water distribution using EPANET 2.0 software on flow velocity shows the lowest rate of 0.29 m/s and the highest of 1.21 m/s. The lowest pressure value in the distribution system is 6.94-6.96 m and headloss units in the range 0.08-0.25 m/km. These three criteria are still within the distribution network design criteria (feasible). A carbon footprint can be calculated from each activity from the analysis of the evaluation of clean water distribution networks. The most massive emissions came from pumping activities with 131 kg CO2-eq, followed by emissions from wastewater 62.5 kgCO2-eq. Further research is needed to determine the quality of wastewater and the design for a centralized wastewater treatment plant (IPALT) to improve Lengkang Kecil Island residents' living standards.Keywords: Lengkang Kecil Island, water, EPANET, carbon footprintABSTRAKJaringan sistem penyediaan air bersih pada Pulau Lengkang Kecil dimulai pada tahun 2019. Sebagian kecil air bersih yang digunakan masyarakat berasal dari pemanenan air hujan dan sumur gali yang hanya didapat pada musim hujan. Sumber air bersih utama yang digunakan masyarakat berasal dari pengaliran perpipaan bawah laut dengan debit harian 0,86 l/detik. Kebutuhan air masyarakat Pulau Lengkang Kecil adalah 74,3 m3/hari dengan 146 Sambungan Rumah (SR) serta untuk melayani fasilitas umum seperti sekolah dasar (SD), puskesmas, dan masjid. Evaluasi hidrolis distribusi air bersih dengan menggunakan software EPANET 2.0 terhadap kriteria kecepatan aliran menunjukkan nilai terendah 0,29 m/s dan tertinggi 1,21 m/s. Nilai sisa tekan dalam sistem distribusi adalah 6,94–6,96 m dan unit headloss pada kisaran 0,08–0,25 m/km. Ketiga kriteria ini masih berada dalam kriteria desain jaringan distribusi (layak). Dari analisis evaluasi jaringan distribusi air bersih, dapat dihitung jejak karbon yang dihasilkan dari setiap kegiatannya. Emisi terbesar berasal dari kegiatan pemompaan dengan nilai 131 kgCO2-eq, diikuti dengan emisi yang berasal dari air limbah dengan nilai 62,5 kgCO2-eq. Penelitian lanjutan diperlukan untuk mengetahui kualitas dari air limbah dan desain untuk instalasi pengolahan air limbah terpusat (IPALT) untuk meningkatkan taraf hidup penduduk Pulau Lengkang Kecil.Kata kunci: Pulau Lengkang Kecil, air, EPANET, jejak karbon

Determining the Norton’s Equivalent Model of Distribution System with Distributed Generation (DG) for Stability Analysis

2019 ◽  
Vol 12 (2) ◽  
pp. 190-198
Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar
Keyword(s):  
Distributed Generation ◽  
Normal Condition ◽  
Distribution System ◽  
Distribution Networks ◽  
Equivalent Model ◽  
Stability Factor ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Issues

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

scholarly journals Microgrid as a Cost-Effective Alternative to Rural Network Underground Cabling for Adequate Reliability

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1978 ◽  
Author(s):  
Sanna Uski ◽  
Erkka Rinne ◽  
Janne Sarsama
Keyword(s):  
Case Studies ◽  
Power Supply ◽  
Dairy Farm ◽  
Cost Effective ◽  
Distribution Networks ◽  
Comparison Method ◽  
Economic Benefits ◽  
Economic Feasibility ◽  
Cost Calculation ◽  
Islanded Operation

Microgrids can be used for securing the supply of power during network outages. Underground cabling of distribution networks is another effective but conventional and expensive alternative to enhance the reliability of the power supply. This paper first presents an analysis method for the determination of microgrid power supply adequacy during islanded operation and, second, presents a comparison method for the overall cost calculation of microgrids versus underground cabling. The microgrid power adequacy during a rather long network outage is required in order to indicate high level of reliability of the supply. The overall cost calculation considers the economic benefits and costs incurred, combined for both the distribution network company and the consumer. Whereas the microgrid setup determines the islanded-operation power adequacy and thus the reliability of the supply, the economic feasibility results from the normal operations and services. The methods are illustrated by two typical, and even critical, case studies in rural distribution networks: an electric-heated detached house and a dairy farm. These case studies show that even in the case of a single consumer, a microgrid option could be more economical than network renovation by underground cabling of a branch in order to increase the reliability.

scholarly journals Low-complexity beam-domain channel estimation and power allocation in hybrid architecture massive MIMO systems

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Xiao Chen ◽  
Zaichen Zhang ◽  
Liang Wu ◽  
Jian Dang
Keyword(s):  
Channel Estimation ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Mimo Systems ◽  
Beam Steering ◽  
Estimation Method ◽  
Low Complexity ◽  
Estimation Accuracy ◽  
Hybrid Architecture

Abstract In this journal, we investigate the beam-domain channel estimation and power allocation in hybrid architecture massive multiple-input and multiple-output (MIMO) communication systems. First, we propose a low-complexity channel estimation method, which utilizes the beam steering vectors achieved from the direction-of-arrival (DOA) estimation and beam gains estimated by low-overhead pilots. Based on the estimated beam information, a purely analog precoding strategy is also designed. Then, the optimal power allocation among multiple beams is derived to maximize spectral efficiency. Finally, simulation results show that the proposed schemes can achieve high channel estimation accuracy and spectral efficiency.

scholarly journals Real Fault Location in a Distribution Network Using Smart Feeder Meter Data

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3242
Author(s):  
Hamid Mirshekali ◽  
Rahman Dashti ◽  
Karsten Handrup ◽  
Hamid Reza Shaker
Keyword(s):  
Fault Location ◽  
Network Reliability ◽  
Distribution Network ◽  
Estimation Method ◽  
Electrical Energy ◽  
Distribution Networks ◽  
Active Power ◽  
Financial Loss ◽  
Smart Meters ◽  
The Real

Distribution networks transmit electrical energy from an upstream network to customers. Undesirable circumstances such as faults in the distribution networks can cause hazardous conditions, equipment failure, and power outages. Therefore, to avoid financial loss, to maintain customer satisfaction, and network reliability, it is vital to restore the network as fast as possible. In this paper, a new fault location (FL) algorithm that uses the recorded data of smart meters (SMs) and smart feeder meters (SFMs) to locate the actual point of fault, is introduced. The method does not require high-resolution measurements, which is among the main advantages of the method. An impedance-based technique is utilized to detect all possible FL candidates in the distribution network. After the fault occurrence, the protection relay sends a signal to all SFMs, to collect the recorded active power of all connected lines after the fault. The higher value of active power represents the real faulty section due to the high-fault current. The effectiveness of the proposed method was investigated on an IEEE 11-node test feeder in MATLAB SIMULINK 2020b, under several situations, such as different fault resistances, distances, inception angles, and types. In some cases, the algorithm found two or three candidates for FL. In these cases, the section estimation helped to identify the real fault among all candidates. Section estimation method performs well for all simulated cases. The results showed that the proposed method was accurate and was able to precisely detect the real faulty section. To experimentally evaluate the proposed method’s powerfulness, a laboratory test and its simulation were carried out. The algorithm was precisely able to distinguish the real faulty section among all candidates in the experiment. The results revealed the robustness and effectiveness of the proposed method.

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