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 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.

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.

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 Rotational Load Flow Method for Radial Distribution Systems

2016 ◽  
Vol 6 (3) ◽  
pp. 1344
Author(s):  
Diego Issicaba ◽  
Jorge Coelho
Keyword(s):  
Radial Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
System Analysis ◽  
Distribution Networks ◽  
Load Flow ◽  
Active Power ◽  
Actual Distribution ◽  
Flow Method ◽  
Node Voltage

This paper introduces a modified edition of classical Cespedes' load flow method to radial distribution system analysis. In the developed approach, a distribution network is modeled in different complex reference systems and reduced to a set of connected equivalent subnetworks, each without resistance, while graph topology and node voltage solution are preserved. Active power losses are then not dissipated in the modeled subnetworks and active power flows can be obtained as a consequence of radiality. Thus, the proposed method preprocesses a series of variable transformations concomitant to an iterative algorithm using a forward-backward sweep to arrive at the load flow solution. The proposed approach has been tested using literature and actual distribution networks, and efficiency improvements are verified in comparison to Cespedes' load flow method.

scholarly journals Power Flow Analysis of Weakly Meshed Distribution Network Including DG

2018 ◽  
Vol 8 (5) ◽  
pp. 3398-3404 ◽  
Author(s):  
A. Al-Sakkaf ◽  
M. AlMuhaini
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Flow Analysis ◽  
Load Flow ◽  
Power Distribution Systems ◽  
Power Flow Analysis ◽  
Bus Voltage ◽  
Flow Study

Power flow is one of the essential studies in power system operation and planning. All steady-state parameters for power distribution systems, such as bus voltage magnitudes, angles, power flows, and power losses, can be calculated by conducting power flow analysis. Distribution system features differ from those of transmission system, rendering conventional load flow algorithms inapplicable. In this paper, three distribution power flow techniques are presented and tested to evaluate their performance when applied to a networked distribution system including distributed generation (DG). These are the distribution load flow (DLF) matrix, the enhanced Newton Raphson (ENR), and the robust decoupled (RD) method. IEEE 33-bus system is adopted for implementing the above methods. Radial and weakly meshed configurations are applied to the tested system with DG inclusion to investigate their influence on the power flow study findings.

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>

Rotational Load Flow Method for Radial Distribution Systems

2016 ◽  
Vol 6 (3) ◽  
pp. 1344
Author(s):  
Diego Issicaba ◽  
Jorge Coelho
Keyword(s):  
Radial Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
System Analysis ◽  
Distribution Networks ◽  
Load Flow ◽  
Active Power ◽  
Actual Distribution ◽  
Flow Method ◽  
Node Voltage

This paper introduces a modified edition of classical Cespedes' load flow method to radial distribution system analysis. In the developed approach, a distribution network is modeled in different complex reference systems and reduced to a set of connected equivalent subnetworks, each without resistance, while graph topology and node voltage solution are preserved. Active power losses are then not dissipated in the modeled subnetworks and active power flows can be obtained as a consequence of radiality. Thus, the proposed method preprocesses a series of variable transformations concomitant to an iterative algorithm using a forward-backward sweep to arrive at the load flow solution. The proposed approach has been tested using literature and actual distribution networks, and efficiency improvements are verified in comparison to Cespedes' load flow method.

A New Power Flow Algorithm for Passive and Active Radial Distribution Networks

2018 ◽  
Vol 40 ◽  
pp. 101-118 ◽  
Author(s):  
M.A. Abdelkader ◽  
Mostafa A. Elshahed ◽  
Zeinab H. Osman
Keyword(s):  
Convergence Rate ◽  
Radial Distribution ◽  
Distribution Systems ◽  
Distribution Networks ◽  
High Ratio ◽  
Load Flow ◽  
Voltage Profile ◽  
Forward Algorithm ◽  
High Convergence Rate ◽  
Radial Distribution Networks

Due to the rapid increase in electricity consumption, there is a tendency to install distributed generations (DGs) at the level of distribution systems. Therefore, the distribution systems become active, and special load flow methods have to be developed and applied due to its radial structure and the relatively high ratio of resistance to reactance components. This paper presents a new forward algorithm for balanced three-phase load-flow analysis of radial distribution networks (RDNs). Kirchhoff’s Current Law and Kirchhoff’s Voltage Law are utilized. However, a new arrangement of these equations is presented based on formation of virtual slack buses and subsystems truncated from the original network during iteration. The proposed algorithm firstly applied on three IEEE benchmark RDNs with different cases such as different load models, various loading levels to illustrate the convergence even high loading, and inserted DGs,; then it is applied on a real system in Egypt. Its high convergence rate is tested for the DG optimization problem. Further, the virtual subsystems can be utilized to recognize quickly the effect of load changes on the bus voltage profile. The results show that the proposed algorithm is more accurate, not sensitive to initial value, simple equations are used, and robust with high convergence rate because of employing the updated bus voltages immediately after determining their value.

scholarly journals Multiple DGs for Reducing Total Power Losses in Radial Distribution Systems Using Hybrid WOA-SSA Algorithm

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Khalid Mohammed Saffer Alzaidi ◽  
Oguz Bayat ◽  
Osman N. Uçan
Keyword(s):  
Radial Distribution ◽  
Distribution Systems ◽  
Distribution Networks ◽  
Load Flow ◽  
Optimal Placement ◽  
Total Power ◽  
Voltage Profile ◽  
Power Losses ◽  
Standard Case ◽  
Whale Optimization

Distributed generators (DGs) are currently extensively used to reduce power losses and voltage deviations in distribution networks. The optimal location and size of DGs achieve the best results. This study presents a novel hybridization of new metaheuristic optimizations in the last two years, namely, salp swarm algorithm (SSA) and whale optimization algorithm (WOA), for optimal placement and size of multi-DG units in radial distribution systems to minimize total real power losses (kW) and solve voltage deviation. This hybrid algorithm is implemented on IEEE 13- and 123-node radial distribution test systems. The OpenDSS engine is used to solve the power flow to find the power system parameters, such power losses, and the voltage profile through the MATLAB coding interface. Results describe the effectiveness of the proposed hybrid WOA-SSA algorithm compared with those of the IEEE standard case (without DG), repeated load flow method, and WOA and SSA algorithms applied independently. The analysis results via the proposed algorithm are more effective for reducing total active power losses and enhancing the voltage profile for various distribution networks and multi-DG units.

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.

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