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 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 A Direct Method for Distribution System Load Flow Solutions

2019 ◽  
Vol 8 (6S3) ◽  
pp. 749-753
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Jacobian Matrix ◽  
Direct Method ◽  
Distribution Networks ◽  
Vital Role ◽  
Load Flow ◽  
Distribution Automation ◽  
Voltage Profile

Load flow or power flow studies are plays vital role in power system operation and control. These load flows are used to find voltage profile, power flow and losses etc. at each and every buses and branches. Traditional LU decomposition and forward-backward methods are consuming more time to run load flows due to Jacobian matrix. The proposed solution A direct approach method for distribution load flow solutions does not required any Jacobian matrix to load flow solution, hence this solution is time efficient and robust. Using special properties of distribution networks two simple matrices are formed. One is bus injection to branch current and other branch current to bus voltage matrix, by multiplying these two matrices to obtain required load flow solution.Test results gives the clear picture about this method. This method having grate capacity touse in unbalanced multiphase distribution automation applications, mostly on very large distribution systems. This project tested with the input data of 15 bus and 33 bus radial distribution system and also a 9 bus system data which includes Distribution Generation.

scholarly journals Allocation of distributed generation and capacitor banks in distribution system

2019 ◽  
Vol 13 (2) ◽  
pp. 437 ◽  
Author(s):  
Olatunde Oladepo ◽  
Hasimah Abdul Rahman
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Optimal Placement ◽  
Voltage Profile ◽  
Power Losses ◽  
Capacitor Banks ◽  
Reactive Power Flow ◽  
Imaginary Power

<p>Voltage profile and power losses on the distribution system is a function of real and imaginary power loading condition. This can be effectively managed through the controlled real and reactive power flow by optimal placement of capacitor banks (CB) and distributed generators (DG). This paper presents adaptive Particle Swarm Optimization (MPSO) to efficiently tackle the problem of simultaneous allocation of DG and CB in radial distribution system to revamp voltage magnitude and reduce power losses. The modification to the conventional PSO was achieved by replacing the inertial weight equation (W) in the velocity update equation base on the particle best experience in the previous iteration. The inertial weight equation is designed to vary with respect to the iteration value in the algorithm. The proposed method was investigated on IEEE 30-bus, 33-bus and 69-bus test distribution systems. The results shows a significant improvement in the rate of convergence of APSO, improved voltage profile and loss reduction.</p>

ANALYSIS OF POWER LOSSES DUE TO DISTRIBUTED GENERATION INCREASE ON DISTRIBUTION SYSTEM

2016 ◽  
Vol 78 (6-3) ◽  
Author(s):  
Hadi Suyono ◽  
Rini Nur Hasanah
Keyword(s):  
Power Plant ◽  
Wind Power ◽  
Distributed Generation ◽  
Distribution System ◽  
Power Flow ◽  
Power Plants ◽  
Distribution Systems ◽  
Small Scale ◽  
Voltage Profile ◽  
Power Losses

Small-scale power plants injected into the existing distribution systems are commonly called as embedded or dispersed generation. The continuously increasing penetration of distributed generation becomes a challenge for conventional power systems. Recently developed distributed generation systems are mostly categorized into small scale plants in terms of power output. However, they are expected to be massive in terms of number. The power plants injection as well as their spread in the whole distribution systems will influence the power flow and losses in the network. Some researches have been undertaken recently to relate the embedded plants with the power losses and voltage profile of the networks. This paper presents a study on the influence of penetration level and concentration of distributed generation on power losses in the network. Steady-state power flow analysis is used to examine the power losses variation for a variety of distributed generation penetration. Based on the power flow analysis, voltage profile and power losses due to the power plants injection can be determined. The influence of various technologies used is also considered, including the use of wind power, photovoltaic and micro-hydro power plants. Four different scenarios to determine the effect of dispersed generation injection are proposed, starting from the original grid in the first scenario, being added with photovoltaic plant (0.5MVA) in the second scenario, the addition of wind power plant (0.5MVA) to the grid in the third scenario, and the fourth is the addition of microhydro power plant (1x2.5MVA) to the grid. The considered scenarios are based on the existing potential of the plants in the network system under concern, i.e. the Sengkaling Substation of the Pujon Feeder in Malang, Indonesia. Based on the analysis results, the injection of microhydro power plant (Scenario 4) presents the best influence being compared to the three other scenarios. The microhydro power potential is greater than that of the PV and wind power plants. Besides, it is well located in the middle of distribution system. From the point of view of power loss analysis, Scenario 4 also results in the smallest loss compared to the other scenarios. The least favorable losses reduction is given by Scenario 3 using the wind power plant injection, although the injection of renewable energy power plants in this study in general is proven to improve the voltage profile and reduction of power losses in the system.    

scholarly journals A new meta-heuristic pathfinder algorithm for solving optimal allocation of solar photovoltaic system in multi-lateral distribution system for improving resilience

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Varaprasad Janamala
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Optimal Allocation ◽  
Photovoltaic System ◽  
Solar Photovoltaic ◽  
Voltage Profile ◽  
Pv System ◽  
Solar Photovoltaic System ◽  
The Impact

AbstractA new meta-heuristic Pathfinder Algorithm (PFA) is adopted in this paper for optimal allocation and simultaneous integration of a solar photovoltaic system among multi-laterals, called interline-photovoltaic (I-PV) system. At first, the performance of PFA is evaluated by solving the optimal allocation of distribution generation problem in IEEE 33- and 69-bus systems for loss minimization. The obtained results show that the performance of proposed PFA is superior to PSO, TLBO, CSA, and GOA and other approaches cited in literature. The comparison of different performance measures of 50 independent trail runs predominantly shows the effectiveness of PFA and its efficiency for global optima. Subsequently, PFA is implemented for determining the optimal I-PV configuration considering the resilience without compromising the various operational and radiality constraints. Different case studies are simulated and the impact of the I-PV system is analyzed in terms of voltage profile and voltage stability. The proposed optimal I-PV configuration resulted in loss reduction of 77.87% and 98.33% in IEEE 33- and 69-bus systems, respectively. Further, the reduced average voltage deviation index and increased voltage stability index result in an improved voltage profile and enhanced voltage stability margin in radial distribution systems and its suitability for practical applications.

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 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 Optimal Allocation of Capacitor Bank for Loss Minimization and Voltage Improvement Using Analytical Method

SCITECH Nepal ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 1-7
Author(s):  
Avinash Khatri KC ◽  
Tika Ram Regmi
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Optimal Allocation ◽  
Reactive Power ◽  
Capacitor Bank ◽  
Minimum Cost ◽  
Distribution Networks ◽  
Standard Test ◽  
Load Flow ◽  
Voltage Profile

An electric distribution system plays an important role in achieving satisfactory power supply. The quality of power is measured by voltage stability and profile of voltage. The voltage profile is affected by the losses in distribution system. As the load is mostly inductive on the distribution system and requires large reactive power, most of the power quality problems can be resolved with requisite control of reactive power. Capacitors are often installed in distribution system for reactive power compensation. This paper presents two stage procedures to identify the location and size of capacitor bank. In the first stage, the load flow is carried out to find the losses of the system using sweep algorithm. In the next stage, different size of capacitors are initialized and placed in each possible candidate bus and again load flow for the system is carried out. The objective function of the cost incorporating capacitor cost and loss cost is formulated constrained with voltage limits. The capacitor with the minimum cost is selected as the optimized solution. The proposed procedure is applied to different standard test systems as 12-bus radial distribution systems. In addition, the proposed procedure is applied on a real distribution system, a section of Sallaghari Feeder of Thimi substation. The voltage drops and power loss before and after installing the capacitor were compared for the system under test in this work. The result showed better voltage profiles and power losses of the distribution system can be improved by using the proposed method and it can be a benefit to the distribution networks.

scholarly journals Optimal Phase Arrangement of Distribution Transformers for System Unbalance Improvement and Loss Reduction

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 545 ◽  
Author(s):  
Chia-Sheng Tu ◽  
Ming-Tang Tsai
Keyword(s):  
Distribution System ◽  
Load Flow ◽  
Phase Selection ◽  
Customer Information ◽  
Distribution Transformers ◽  
Three Phase ◽  
Phase Combination ◽  
Line Loss ◽  
Operating Constraints ◽  
Selection Of

This paper presents an efficient strategy for transformer planning to reduce the system losses by means of transformer rearrangement. The customer connected to the distribution transformer are first investigated by the field survey, and the loads of the various customers are collected from the customer information system (CIS) and distribution database system (DAS) to derive their load patterns. The objective function is to minimize the total line loss in the 24 intervals. An improved bacterial foraging algorithm (IBFO) is proposed herein to find the optimal phase combination of distribution transformers to minimize the total line loss by considering operating constraints. A three-phase load flow program with Eeuivalent current injection (ECT) is used to solve the total line loss and system unbalance factor on a Taipower distribution system. The results can help operators not only perform the proper installation phase selection of distribution transformers, but also reduce the system losses, decrease the system unbalance factor, and improve the voltage profiles of the buses.

Optimal Capacitors in Radial Distribution System for Loss Reduction and Voltage Enhancement

2016 ◽  
Vol 2 (3) ◽  
pp. 566 ◽  
Author(s):  
S. Bhongade ◽  
Sachin Arya
Keyword(s):  
Radial Distribution ◽  
Distribution System ◽  
Power Loss ◽  
Distribution Systems ◽  
Pso Algorithm ◽  
Load Flow ◽  
Base Case ◽  
Voltage Profile ◽  
Radial Distribution System ◽  
Case Load

The work presented in this paper is carried out with the objective of identifying the optimal location and size (Kvar ratings) of shunt capacitors to be placed in radial distribution system, to have overall economy considering the saving due to energy loss minimization. To achieve this objective, a two stage methodology is adopted in this paper. In the first stage, the base case load flow of uncompensated distribution system is carried out. On the basis of base case load flow solution, Nominal voltage magnitudes and Loss Sensitivity Factors are calculated and the weak buses are selected for capacitor placement.In the second stage, Particle Swarm Optimization (PSO) algorithm is used to identify the size of the capacitors to be placed at the selected buses for minimizing the power loss. The developed algorithm is tested for 10-bus, 34-bus and 85-bus Radial Distribution Systems. The results show that there has been an enhancement in voltage profile and reduction in power loss thus resulting in much annual saving.

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