scholarly journals Decentralized Voltage Optimization Based on the Auxiliary Problem Principle in Distribution Networks with DERs

2021 ◽  
Vol 11 (10) ◽  
pp. 4509
Author(s):  
Anna Rita Di Fazio ◽  
Chiara Risi ◽  
Mario Russo ◽  
Michele De Santis
Keyword(s):  
Distribution Systems ◽  
Auxiliary Problem ◽  
Optimization Procedure ◽  
Distribution Networks ◽  
Small Dimension ◽  
Quadratic Program ◽  
Voltage Profile ◽  
Distributed Energy ◽  
Auxiliary Problem Principle ◽  
Coordination Process

This paper addresses the problem of optimizing the voltage profile of radially-operated distribution systems by acting on the active and reactive powers provided by distributed energy resources (DERs). A novel voltage optimization procedure is proposed by adopting a decentralized control strategy. To this aim, a centralized voltage optimization problem (VOP), minimizing the distance of all the nodal voltages from their reference values, is firstly formulated as a strictly-convex quadratic program. Then, the centralized VOP is rewritten by partitioning the network into voltage control zones (VCZs) with pilot nodes. To overcome the lack of strictly convexity determined by the reduction to the pilot nodes, the dual centralized VOP working on the augmented Lagrangian function is reformulated and iteratively solved by the method of multipliers. Finally, a fully-distributed VOP solution is obtained by applying a distributed algorithm based on the auxiliary problem principle, which allows for solving in each VCZ a quadratic programming problem of small dimension and to drive the VCZ solutions toward the overall optimum by an iterative coordination process that requires to exchange among the VCZs only scalar values. The effectiveness and feasibility of the proposed method have been demonstrated via numerical tests on the IEEE 123-bus system.

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 Adaptive Impedance-Based Fault Location Algorithm for Active Distribution Networks

2018 ◽  
Vol 8 (9) ◽  
pp. 1563 ◽  
Author(s):  
Cesar Orozco-Henao ◽  
Arturo Suman Bretas ◽  
Juan Marín-Quintero ◽  
Andres Herrera-Orozco ◽  
Juan Pulgarín-Rivera ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Fault Location ◽  
Real Life ◽  
Distribution Networks ◽  
Maximum Error ◽  
Energy Resources ◽  
Distributed Energy Resources ◽  
Distributed Energy ◽  
Power Sources ◽  
Location Algorithm

Modern fault location methods are robust; however, they depend strongly on the availability of the measurements given by Distributed Energy Resources (DER). If the communication or synchronism of this information is lost, the fault location is not possible. This paper proposes an adaptive impedance-based fault location algorithm for active distribution systems. The proposal combines information provided by Intelligent Electronic Devices (IEDs) located at the substation, the knowledge of the network topology and parameters, as well as the distributed power sources, to estimate the fault location. Its adaptive feature is given by the use of a Distributed Energy Resources (DER) electrical model. This model is used to estimate the DER current contribution to the fault, in case the information provided by a local IED is not available. The method takes two types of DER technologies into account: Inverter non-interfaced DER (INIDER) and Inverter-interfaced DER (IIDER). The proposed method is validated on a modified IEEE 34-node test feeder, which was simulated with ATP/EMTP. The results obtained using the IEDs information, presented a maximum error of 0.8%. When this information is not available, the method’s performance decreases slightly, obtaining a maximum error of 1.1%. The proposed method showed better performance when compared with two state of the art methods, indicating potential use for real-life applications.

scholarly journals Optimal Allocation of DSTATCOM in Distribution Network Using Whale Optimization Algorithm

2018 ◽  
Vol 8 (5) ◽  
pp. 3445-3449 ◽  
Author(s):  
P. Balamurugan ◽  
T. Yuvaraj ◽  
P. Muthukannan
Keyword(s):  
Optimization Algorithm ◽  
Distribution Systems ◽  
Optimal Allocation ◽  
Stability Index ◽  
Distribution Networks ◽  
Whale Optimization Algorithm ◽  
Voltage Profile ◽  
Power Losses ◽  
Whale Optimization ◽  
Static Compensator

This paper deals with a new approach implemented to decrease power losses and improve voltage profile in distribution networks using Distribution STATic COMpensator (DSTATCOM). DSTATCOM location can be determined by the voltage stability index (VSI) and sizing can be identified by nature inspired, recently developed whale optimization algorithm (WOA). To check efficacy, the proposed technique is tested on two standard buses: Indian rural electrification 28-bus and IEEE 69-bus distribution systems. Obtained results show that optimal allocation of DSTATCOM effectively reduces power losses and improves voltage profile.

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 Active Power Loss Reduction for Radial Distribution Systems by Placing Capacitors and PV Systems with Geography Location Constraints

2020 ◽  
Vol 12 (18) ◽  
pp. 7806 ◽  
Author(s):  
Thuan Thanh Nguyen ◽  
Bach Hoang Dinh ◽  
Thai Dinh Pham ◽  
Thang Trung Nguyen
Keyword(s):  
Power Loss ◽  
Distribution Systems ◽  
Distribution Networks ◽  
Active Power ◽  
Total Power ◽  
Voltage Profile ◽  
Pv System ◽  
Pv Systems ◽  
Search Optimization ◽  
Power Loss Reduction

This paper presents a highly effective method of installing both capacitors and PV systems in distribution systems for the purpose of reducing total power loss in branches. Three study cases with the installation of one capacitor, two capacitors and three capacitors were implemented and then the optimal solutions were used to install one more photovoltaic (PV) system. One PV system with 20% active power of all loads and less than active power of all loads was tested for two different conditions: (1) with geography location constraint and (2) without geography location constraint for PV system placement. The results from two systems consisting of 33 and 69 nodes were obtained by using the Stochastic Fractal Search Optimization Algorithm (SFSOA). Simulation results show that this method can determine the appropriate location and size of capacitors to reduce the total power losses more effectively than other existing methods. Furthermore, the paper also demonstrates the real impact of using both capacitors and PV systems to reduce active power loss as well as improve the voltage profile of distribution systems. This paper also finds that if it is possible to place PV systems in all nodes in distribution systems, the benefit from reducing total loss is highly significant and the investment of PV system placement is highly encouraged. As a result, it is recommended that capacitors and PV systems be used in distribution networks, and we claim that two important factors of the installed components consisting of location and size can be determined effectively by using SFSOA.

scholarly journals SPSO Based Optimal Integration of DGs in Local Distribution Systems under Extreme Load Growth for Smart Cities

Electronics ◽  
2021 ◽  
Vol 10 (20) ◽  
pp. 2542
Author(s):  
Mian Rizwan ◽  
Muhammad Waseem ◽  
Rehan Liaqat ◽  
Intisar Ali Sajjad ◽  
Udaya Dampage ◽  
...  
Keyword(s):  
Distribution System ◽  
Power Loss ◽  
Distribution Systems ◽  
Smart Cities ◽  
Electrical Energy ◽  
Distribution Networks ◽  
Economic Benefits ◽  
Voltage Profile ◽  
Extreme Load ◽  
System Nodes

Renewable energy-based distributed generators (DGs) are gaining more penetration in modern grids to meet the growing demand for electrical energy. The anticipated techno-economic benefits of these eco-friendly resources require their judicious and properly sized allocation in distribution networks (DNs). The preeminent objective of this research is to determine the sizing and optimal placing of DGs in the condensed DN of a smart city. The placing and sizing problem is modeled as an optimization problem to reduce the distribution loss without violating the technical constraints. The formulated model is solved for a radial distribution system with a non-uniformly distributed load utilizing the selective particle swarm optimization (SPSO) algorithm. The intended technique decreases the power loss and perfects the voltage profile at the system’s nodes. MATLAB is used for the simulation, and the obtained results are also validated by the Electrical Transient Analysis Program (ETAP). Results show that placing optimally sized DGs at optimal system nodes offers a considerable decline in power loss with an improved voltage profile at the network’s nodes. Distribution system operators can utilize the proposed technique to realize the reliable operation of overloaded urban networks.

scholarly journals A hybrid algorithm for voltage stability enhancement of distribution systems

2022 ◽  
Vol 12 (1) ◽  
pp. 50
Author(s):  
Hazim Sadeq Mohsin Al-Wazni ◽  
Shatha Suhbat Abdulla Al-Kubragyi
Keyword(s):  
Radial Distribution ◽  
Distribution System ◽  
Hybrid Algorithm ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Distribution Networks ◽  
Optimal Operation ◽  
Total Power ◽  
Optimal Size ◽  
Voltage Profile

This paper presents a hybrid algorithm by applying a hybrid firefly and particle swarm optimization algorithm (HFPSO) to determine the optimal sizing of distributed generation (DG) and distribution static compensator (D-STATCOM) device. A multi-objective function is employed to enhance the voltage stability, voltage profile, and minimize the total power loss of the radial distribution system (RDS). Firstly, the voltage stability index (VSI) is applied to locate the optimal location of DG and D-STATCOM respectively. Secondly, to overcome the sup-optimal operation of existing algorithms, the HFPSO algorithm is utilized to determine the optimal size of both DG and D-STATCOM. Verification of the proposed algorithm has achieved on the standard IEEE 33-bus and Iraqi 65-bus radial distribution systems through simulation using MATLAB. Comprehensive simulation results of four different cases show that the proposed HFPSO demonstrates significant improvements over other existing algorithms in supporting voltage stability and loss reduction in distribution networks. Furthermore, comparisons have achieved to demonstrate the superiority of HFPSO algorithms over other techniques due to its ability to determine the global optimum solution by easy way and speed converge feature.

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.

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