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 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 A Novel Analytical Approach for Optimal Placement and Sizing of Distributed Generations in Radial Electrical Energy Distribution Systems

2021 ◽  
Vol 13 (18) ◽  
pp. 10224
Author(s):  
Sasan Azad ◽  
Mohammad Mehdi Amiri ◽  
Morteza Nazari Heris ◽  
Ali Mosallanejad ◽  
Mohammad Taghi Ameli
Keyword(s):  
Radial Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Reducing Power ◽  
Distribution Networks ◽  
Active Power ◽  
Optimal Placement ◽  
Power Losses ◽  
Active Power Losses

Considering the strong influence of distributed generation (DG) in electric distribution systems and its impact on network voltage losses and stability, a new challenge has appeared for such systems. In this study, a novel analytical algorithm is proposed to distinguish the optimal location and size of DGs in radial distribution networks based on a new combined index (CI) to reduce active power losses and improve system voltage profiles. To obtain the CI, active power losses and voltage stability indexes were used in the proposed approach. The CI index with sensitivity analysis was effective in decreasing power losses and improving voltage stability. Optimal DG size was determined based on a search algorithm to reduce active power losses. The considered scheme was examined through IEEE 12-bus and 33-bus radial distribution test systems (RDTS), and the obtained results were compared and validated in comparison with other available methods. The results and analysis verified the effectiveness of the proposed algorithm in reducing power losses and improving the distribution system voltage profiles by determining the appropriate location and optimal DG size. In IEEE 12 and 33 bus networks, the minimum voltage increased from 0.9434 p.u and 0.9039 p.u to 0.9907 p.u and 0.9402 p.u, respectively. Additionally, the annual cost of energy losses decreased by 78.23% and 64.37%, respectively.

An Efficient Load Flow Method for Weakly Meshed and Radial Distribution Systems

2008 ◽  
Vol 2 (2) ◽  
pp. 55-62
Author(s):  
J. Viswanatha Rao ◽  
S. Sivanagaraju ◽  
P. Umapathi Reddy ◽  
G. Srinivas
Keyword(s):  
Radial Distribution ◽  
Distribution Systems ◽  
Load Flow ◽  
Flow Method

Multi-objective optimization of optimal capacitor allocation in radial distribution systems

2020 ◽  
Vol 21 (3) ◽  
Author(s):  
Sayed Mir Shah Danish ◽  
Mikaeel Ahmadi ◽  
Atsushi Yona ◽  
Tomonobu Senjyu ◽  
Narayanan Krishna ◽  
...  
Keyword(s):  
Radial Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Reactive Power ◽  
Stability Index ◽  
Distribution Networks ◽  
Optimization Method ◽  
Optimal Size ◽  
Multi Objective Optimization ◽  
Multi Objective

AbstractThe optimal size and location of the compensator in the distribution system play a significant role in minimizing the energy loss and the cost of reactive power compensation. This article introduces an efficient heuristic-based approach to assign static shunt capacitors along radial distribution networks using multi-objective optimization method. A new objective function different from literature is adapted to enhance the overall system voltage stability index, minimize power loss, and to achieve maximum net yearly savings. However, the capacitor sizes are assumed as discrete known variables, which are to be placed on the buses such that it reduces the losses of the distribution system to a minimum. Load sensitive factor (LSF) has been used to predict the most effective buses as the best place for installing compensator devices. IEEE 34-bus and 118-bus test distribution systems are utilized to validate and demonstrate the applicability of the proposed method. The simulation results obtained are compared with previous methods reported in the literature and found to be encouraging.

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.

Evaluation of the Forward-Backward Sweep Load Flow Method using the Contraction Mapping Principle

2016 ◽  
Vol 6 (6) ◽  
pp. 3229
Author(s):  
Diego Issicaba ◽  
Jorge Coelho
Keyword(s):  
Distribution System ◽  
Existence And Uniqueness ◽  
Contraction Mapping ◽  
System Analysis ◽  
Feasible Solution ◽  
Contraction Mapping Principle ◽  
Load Flow ◽  
Contraction Mapping Theorem ◽  
Flow Method ◽  
Theoretical Results

<p>This paper presents an assessment of the forward-backward sweep load flow method to distribution system analysis. The method is formally assessed using fixed-point concepts and the contraction mapping theorem. The existence and uniqueness of the load flow feasible solution is supported by an alternative argument from those obtained in the literature. Also, the closed-form of the convergence rate of the method is deduced and the convergence dependence of loading is assessed. Finally, boundaries for error values per iteration between iterates and feasible solution are obtained. Theoretical results have been tested in several numerical simulations, some of them presented in this paper, thus fostering discussions about applications and future works.</p>

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>

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