scholarly journals A Sustainability-Oriented Multiobjective Optimization Model for Siting and Sizing Distributed Generation Plants in Distribution Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-11
Author(s):  
Guang Chen ◽  
Bin Chen ◽  
Pan Dai ◽  
Hao Zhou
Keyword(s):  
Multiobjective Optimization ◽  
Environmental Sustainability ◽  
Optimization Model ◽  
Distribution System ◽  
Distribution Systems ◽  
Numerical Study ◽  
Economic Cost ◽  
Simulation Method ◽  
Chance Constraints ◽  
Load Flow

This paper proposes a sustainability-oriented multiobjective optimization model for siting and sizing DG plants in distribution systems. Life cycle exergy (LCE) is used as a unified indicator of the entire system’s environmental sustainability, and it is optimized as an objective function in the model. Other two objective functions include economic cost and expected power loss. Chance constraints are used to control the operation risks caused by the uncertain power loads and renewable energies. A semilinearized simulation method is proposed and combined with the Latin hypercube sampling (LHS) method to improve the efficiency of probabilistic load flow (PLF) analysis which is repeatedly performed to verify the chance constraints. A numerical study based on the modified IEEE 33-node system is performed to verify the proposed method. Numerical results show that the proposed semilinearized simulation method reduces about 93.3% of the calculation time of PLF analysis and guarantees satisfying accuracy. The results also indicate that benefits for environmental sustainability of using DG plants can be effectively reflected by the proposed model which helps the planner to make rational decision towards sustainable development of the distribution system.

scholarly journals Numerical Study on Coupled Operation of Stratified Air Distribution System and Natural Ventilation under Multi-Variable Factors in Large Space Buildings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang
Keyword(s):  
Thermal Comfort ◽  
Working Conditions ◽  
Distribution System ◽  
Distribution Systems ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Air Distribution ◽  
Large Space ◽  
Air Conditioners ◽  
Air Supply

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.

scholarly journals Reactive Power Loss & Efficiency Calculation Using Load Flow Technique In Distribution System For Pune City

2012 ◽  
pp. 76-79
Author(s):  
Gaikwad Vikas Subhash ◽  
Swati S. More
Keyword(s):  
Power Systems ◽  
Distribution System ◽  
Power Loss ◽  
Distribution Systems ◽  
Service Sector ◽  
Reactive Power ◽  
Flow Problem ◽  
Load Flow ◽  
Total System ◽  
Loss Efficiency

Reactive power compensation is an important issue in electric power systems, involving operational, economical and quality of service aspects. Consumer loads (residential, industrial, service sector, etc.) impose active and reactive power demand, depending on their characteristics. This paper presents an efficient method for solving the load flow problem in distribution systems and which is implemented for Pune city (India) to check the validity of proposed method. A simple algebraic matrix equation to solve the load flow problem is derived by using the complex power balance equations. By adopting the rectangular coordinate, which requires the neglect of only second order terms in the linearization procedure, the proposed method gives better convergence characteristics. Newton-Raphsonmethod is the famous load flow calculation technique, and normally used dueto its rapidness of numerical convergence. The proposed method estimates the incremental changesof active power on each generation bus with respect to the total system power loss, efficiency and the estimated value are used to update the slack bus power.

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 Real Distribution Network Voltage Regulation Incorporating Auto-Tap-Changer Pole Transformer Multiobjective Optimization

2019 ◽  
Vol 9 (14) ◽  
pp. 2813 ◽  
Author(s):  
Sayed Mir Shah Danish ◽  
Ryuto Shigenobu ◽  
Mitsunaga Kinjo ◽  
Paras Mandal ◽  
Narayanan Krishna ◽  
...  
Keyword(s):  
Multiobjective Optimization ◽  
Power Systems ◽  
Distribution System ◽  
Distribution Systems ◽  
Voltage Regulation ◽  
Power Transfer ◽  
Dimensional Solution ◽  
Protection Measures ◽  
Transfer Capability ◽  
Tap Changer

A number of studies realized operation of power systems are unstable in developing countries due to misconfiguration of distribution systems, limited power transfer capability, inconsistency of renewable resources integration, paucity of control and protection measures, timeworn technologies, and disproportionately topology. This study underlines an Afghanistan case study with 40% power losses that is mainly pertinent from old distribution systems. The long length of distribution systems, low-power transfer capability, insufficient control and protection strategy, peak-demand elimination, and unstable operation (low energy quality and excessive voltage deviations) are perceived pre-eminent challenges of Afghanistan distribution systems. Some attainable solutions that fit challenges are remodeling (network reduction), networks reinforcement, optimum compensation strategy, reconfiguration options, improving, and transfer capability. This paper attempts to propose a viable solution using multiobjective optimization method of auto-tap-changer pole transformer (ATCTr). The proposed methodology in terms of optimal numbers and placement of ATCTr can be known as a novel two-dimensional solution. For this purpose, a real case of Kabul City distribution system is evaluated. Simulation results indicate the effectiveness of the proposed method in reducing system losses and improving system overall performance. This approach tends to regulate the voltage deviation in a proper and statutory range with minimum number and optimum placement of ATCTrs. The proposed method is simulated using MATLAB® environment to compare and evaluate performance of the proposed network under different situations and scenarios.

A Study on Evaluation of ADPI and Ventilation Performance of a Small Auditorium with Unevenly Arranged Return Diffusers

2017 ◽  
Vol 25 (04) ◽  
pp. 1750029
Author(s):  
Yong-il Kwon
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Numerical Study ◽  
Side Wall ◽  
Air Distribution ◽  
Rear Wall ◽  
System Parameters ◽  
Ventilation Efficiency ◽  
Ventilation Performance ◽  
Air Diffusion

The ventilation performance and thermal comfort characteristics on placing the supply or return diffusers for the air distribution systems applied to an auditorium with high ceiling heights must be inherently considered. A numerical study has been conducted to simulate the airflow and ventilation characteristics in a small auditorium with the uniformly installed supply diffusers on the ceiling surface, and with the unevenly installed return diffusers on the side wall of the stage, the left and rear wall. It is the objective of the present study to investigate the effects of various air distribution system parameters on air diffusion performance index (ADPI), air change efficiency and scale of ventilation efficiency NO.4 (SVE4) of return diffusers in the auditorium with the movable audience seat on the flat floor. This paper focuses mainly on the effect of the unevenly installed return diffusers on the low part of the side wall of the auditorium with the movable audience seat.

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.

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.

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