Capacitor Placement In Distribution Networks Research Articles

Shunt capacitor placement in radial distribution networks considering switching transients decision making approach

This paper provides a new approach in decision making process for shunt capacitor placement in distribution networks. The main core of the evaluation process is a multi-objective framework to allocate the capacitor banks. The power loss and the total harmonic distortion (THD) are the objective functions of the system under study in a long-term planning horizon. In order to select the executive plan introduced by using a multi-objective model, transient switching overvoltages have been considered. As the size and location of shunt capacitors may result in unacceptable overvoltages, the proposed technical decision making framework can be applied to avoid corresponding damages. In this paper, an iterative conventional power flow technique is introduced. This technique can be applied to evaluate THD for distribution networks as well as other power flow based objectives, such as power losses calculation and voltage stability assessment. The presented framework is a two stage one where at the first stage, a non-dominated sorting genetic algorithm (NSGA-II) augmented with a local search technique is used in order to solve the addressed multi-objective optimization problem. Then, at the second stage, a decision making support technique is applied to determine the best solution from the obtained Pareto front. In order to evaluate the effectiveness of the proposed method, two benchmarks are addressed in this paper. The first test system is a 9-bus distribution network and the second one is an 85-bus large scale distribution network. The simulation results show that the presented method is satisfactory and consistent with the expectation.

Optimal capacitor placement in distribution networks regarding uncertainty in active power load and distributed generation units production

The paper proposes a new method for optimal allocation of shunt capacitors in distribution network with renewable distributed generation units such as wind turbines and/or solar power plants. The proposed method, based on application of the Monte Carlo simulation methods, respects the uncertainties associated with load demand and renewable sources power production. The optimisation problem is modelled by two criterion functions with the aim of improving voltage profile in a network by optimal selection of the locations and installed powers of the shunt capacitors. The suggested criterion functions have been optimised simultaneously by applying the non-dominated sorting genetic algorithm. On the basis of the measured data on wind speed and solar radiation, the method has been tested by the example of a real distribution network.

Comprehensive framework for capacitor placement in distribution networks from the perspective of distribution system management in a restructured environment

This paper presents a new and comprehensive Objective Function (OF) for capacitor placement in distribution networks. In this study, distribution network management’s viewpoint toward identifying comprehensive OF to maximize the benefit of a distribution company is considered. In addition to considering active power loss cost and capacitor cost, two other important terms, i.e. cost of buying reactive power and voltage drop penalty for maximizing the benefit of distribution companies are considered in the OF. All actual conditions including time varying nature of load, annual load growth, time varying price of active and reactive power, and switchable and fixed capacitor are taken into account based on the reality. The profit derived from the proposed OF is compared with two other common OFs, and it is shown that the benefit achieved from the proposed OF is more than the two other OFs. The proposed OF is validated and tested on radial distribution systems with differing topologies and varying sizes and complexities.

Reliability and economic‐driven switchable capacitor placement in distribution network

In this study, reliability and economic-driven capacitor allocation problem in electrical distribution system is investigated for a definite planning horizon considering several technical and economic aspects. Also, the system reliability modelling is performed based on a new approach, which is considering values of reactive component of currents flowing through branches of the feeder and applying different feeder's failure rate models. The aim of this study is minimising total cost of the system including system power loss cost, system risk cost, investment cost and maintenance cost. Herein, in order to achieve practical outcomes, inflation and interest rates as the economic factors considered in the planning, and yearly load growth, hourly and daily varying load, and customers’ load types are applied in the modelling, and also load model-based power flow is run rather than simple power flow. In this study, it is demonstrated that considering unreal model for the system load types or ignoring dependence of system reliability on the reactive component of current can significantly affect the results of the capacitor placement problem and also it can impose extra cost to the local distribution company.

Optimal capacitor placement in distribution networks using Genetic Algorithm

One of the on-going studies in the power distribution system is optimal placement of capacitors to which designers pay attention since many years ago. The most important benefit of capacitor placement is loss reduction, voltage profi le improvement, increment of power factor and freeing up the power system capacity. This paper presents a new approach for capacitor allocation in a sample distribution system. The problem formulation considers most of effective parameters in the capacitorinstallation. One of the distinguished characteristics of the implementation of the Genetic Algorithm for optimal capacitor placement in distribution system is its multifunction capability. The proposed method on capacitor placement and detecting optimumcapacitance has been implemented and tested in a 9 -bus IEEE sample network in DIGSILENT and MATLAB environments.

Optimal capacitor placement in distribution networks

This paper deals with the voltage stability problem associated with radial distribution networks. Two load models are studied: the full load flow model (FLFM) and the equivalent generic single-line model (EGSLM). Optimization is then carried out to find the optimal capacitor size that minimizes some costing function, and finally several capacitor placement techniques are studied.