A practical loss allocation method should consider size, distance from source, and network usage of its' participants. The power flow pattern in distribution network has changed over a period due to ...increased integration of distributed generation (DG) and hence, the equivalent distance and usage of network have changed for the conventional distribution network. The regulators require a fair and robust model for loss allocation which should be able to discriminate between the contributions of multiple participants. The loss allocation techniques proposed earlier in the literature either require additional quantities over and above power flow solution or are specifically developed only for radial distribution networks. This paper presents a cooperative game approach which provides stable solution integrated with appropriate penalties or rewards to participants. The proposed method provides an analytical solution which is solved using Shapley value for radial as well as weakly meshed distribution network. The memory and computational burden with the Shapley value have been overcome by a final analytical formula that satisfies the axioms of fairness. The use of the method is straightforward without any assumptions and requires only network data and power flow solution. The results are illustrated using different scenarios of DG output levels and network topologies and compared with other methods to establish its effectiveness.
In this paper, an approach for optimal placement of D-STATCOM in mesh distribution systems using sensitivity approaches is proposed. The main contributions of the paper are as follows: (i) Optimal ...D-STATCOM placement based on the new voltage sensitivity index in mesh distribution system, (ii) optimal D-STATCOM size determination for seasonal loads with load growth scenario, (iii) comparison of D-STATCOM placement and size determination with the existing sensitivity methods, and (iv) impact of optimal D-STATCOM placement on voltage stability margin enhancement, energy loss reduction and cost of energy savings.
The results of voltage profile improvement, reduction in power losses, reduction in cost of energy loss, improved voltage stability margin, cost of energy loss savings, installation cost of D-STATCOM and annual savings are obtained for UK 38 bus practical mesh distribution system.
A novel application of General Algebraic Modelling System (GAMS) software has been reported in this paper to determine the load flow solution for both radial and mesh distribution network. With ...interfacing of GAMS and MATLAB, optimal sitting and sizing of Distributed Generator (DG) in radial/mesh distribution systems is efficiently done in order to reduce power loss and improvement of voltage profile in distribution systems.
The main contributions of the paper are as follows:
Load flow solution by GAMS software for both radial and mesh distribution networks.
Planning of optimal sitting and sizing of DG has been carried out in two phases. In first phase, optimal locations of DG based on the Power Loss Sensitivity (PLS) and in second phase, optimal size of DG has been determined by CONOPT solver of GAMS, solves Non-Linear programming (NLP).
Two types of DGs have been considered for analysis i.e. Type 1 (DG operating at unity power factor) and Type 3 (DG operating at lagging power factor).
The results are obtained on IEEE 33-bus and IEEE 69-bus radial distribution systems and also compared with other existing methods. The test results demonstrate that the proposed method produced superior results in respect of loss reduction, improvement in voltage profile and computational time.
•A new MINLP approach is proposed for capacitor placement.•The proposed method is applied to the radial and mesh distribution systems.•Objective of capacitor placement is reduction costs of capacitor ...and power losses.•The capacitor placement solves using GAMS software with SBB and MINLP solvers.•The proposed method is capable to solve large scale systems.
Capacitors in radial/mesh distribution systems are used to supply reactive power to minimize loss and to improve the voltage profile. The appropriate placement of capacitors is also important to ensure that system power losses and total investment capacitor costs are minimal. The capacitor placement problem consists of finding specific sitting and sizing to install capacitor banks in an electrical distribution system. Consequently, the losses are reduced due to the compensation of the reactive component of power flow. This paper presents a new mixed integer nonlinear programming approach for capacitor placement in radial/mesh distribution systems that determine the optimal sitting and sizing of capacitors with an objective of reduction power loss and investment capacitor costs. The proposed method is applied to 10, 34, and 85-bus radial distribution systems and CIVANLAR mesh distribution system. Various-scale application systems are used to compare the performance of the proposed method with the Fuzzy reasoning, particle swim optimization (PSO), plant growth simulation algorithm (PGSA), and Heuristic based. Numerical results show that the performance of the proposed MINLP method is better than the other methods. Also, the MINLP method is superior to some other methods in terms of solution power loss and costs.
The modern distribution networks under the smart grid paradigm have been considered both interconnected and reliable. In grid modernization concepts, the optimal asset optimization across a certain ...planning horizon is of core importance. Modern planning problems are more inclined towards a feasible solution amongst conflicting criteria. In this paper, an integrated decision-making planning (IDMP) approach is proposed. The proposed methodology includes voltage stability assessment indices linked with loss minimization condition-based approach, and is integrated with different multi-criteria decision-making methodologies (MCDM), followed by unanimous decision making (UDM). The proposed IDMP approach aims at optimal assets sitting and sizing in a meshed distribution network to find a trade-off solution with various asset types across normal and load growth horizons. An initial evaluation is carried out with assets such as distributed generation (DG), photovoltaic (PV)-based renewable DG, and distributed static compensator (D-STATCOM) units. The solutions for various cases of asset optimization and respective alternatives focusing on technical only, economic only, and techno-economic objectives across the planning horizon have been evaluated. Later, various prominent MCDM methodologies are applied to find a trade-off solution across different cases and scenarios of assets optimization. Finally, UDM is applied to find trade-off solutions amongst various MCDM methodologies across normal and load growth levels. The proposed approach is carried out across a 33-bus meshed configured distribution network. Findings from the proposed IDMP approach are compared with available works reported in the literature. The numerical results achieved have validated the effectiveness of the proposed planning approach in terms of better performance and an effective trade-off solution across various asset types.
This paper presents a general formulation of the classical iterative-sweep power flow, which is widely known as the backward–forward method. This formulation is performed by a branch-to-node ...incidence matrix with the main advantage that this approach can be used with radial and meshed configurations. The convergence test is performed using the Banach fixed-point theorem while considering the dominant diagonal structure of the demand-to-demand admittance matrix. A numerical example is presented in tutorial form using the MATLAB interface, which aids beginners in understanding the basic concepts of power-flow programming in distribution system analysis. Two classical test feeders comprising 33 and 69 nodes are used to validate the proposed formulation in comparison with conventional methods such as the Gauss–Seidel and Newton–Raphson power-flow formulations.
This paper offers an enhanced voltage stability assessment index (VSAI) and loss minimalize condition (LMC) centered integrated planning approach. The proposed method aims at the simultaneous ...attainment of voltage stability, loss minimizations and various other related objectives with the employment of multiple distributed generation (DG) units, in mesh distribution systems (MDS). The approach presents two enhanced VSAI expressions based on a multiple-loops configured equivalent MDS model. The main objective of each VSAI expression is to find the weakest buses as potential candidates for single and multiple DG placements with initial optimal DG sizes for aimed objectives attainment in MDS. Later, mathematical expressions for LMC have been presented, based on equivalent MDS model. The LMC aims to achieve significant loss minimization with optimal DG sizes and attain negligible voltage difference across tie-line branches via reduction of respective loop currents. The proposed integrated VSAI-LMC based planning approach is employed with two computation variants and tested on two well-known, 33-Bus and 69-Bus, test distribution systems (TDS). The performance analysis of each TDS is conducted with two cases and respective scenarios, across various performance evaluation indicators (PEIs). The paper also offers a comparative analysis of achieved numerical outcomes of the proposed planning approach with the available research works found in the literature. The numerical results attained have better performance in comparison with the presented literature data and thus shows the effectiveness and validity of the proposed planning approach.
This paper offers a new improved voltage stability assessment index (VSAI_B)-centered planning approach, aiming at the attainment of technical and cost related objectives with simultaneous multiple ...asset deployment in a mesh distribution systems (MDS). The assets such as multiple distributed generation (DG) and distributed static compensator (D-STATCOM) units have been utilized; aiming at voltage stabilization, loss minimization, and associated objectives. The proposed planning approach incorporates expressions of VSAI_B aiming at initial simultaneous assets placement followed by loss minimization conditions (LMC) for appropriate asset sizing, which is further utilized for performance evaluations. The VSAI_B-LMC-based integrated planning approach is applied to configured MDS models such as a 33-bus test distribution system (TDS) for detailed analysis. The performance evaluations with the presented approach have been conducted for different cases along with respective scenarios considering various technical and cost-economic performance metrics. First, three cases referring to multiple DGs sitting and sizing for various power factors have been presented, followed later by two cases of multiple DGs and D-STATCOMs with respective evaluation scenarios. Finally, benchmark analysis is conducted on a 69-bus TDS for validity demonstration of the proposed approach. The comparison of achieved results in comparison with the available literature points out toward the validity and improved performance of the proposed approach.
Renewable energy sources-based distributed generation (DG) integration is becoming the integral part of the present-day active distribution networks in the competitive environment. Distribution ...Static compensator (D-STATCOM) devices are playing a key role for better management in terms of planning the reactive power deployment for maintaining the better voltage profile and reduction in the line losses. In this article, a steady-state analysis of mesh distribution system has been carried out with installation of DG and D-STATCOM with large industrial load under load growth scenario. The major objectives of the manuscript are (i) finding the best possible place for D-STATCOM as per proposed new sensitivity index, (ii) sizing of D-STATCOM using variational algorithm based on minimum total cost of energy loss criteria, (iii) determination of percentage feeder released capacity and annual savings in cost of energy loss with DG or/and D-STATCOM. (iv) comparative analysis with simultaneous and individual allocation of DG and D-STATCOM.
Copulas and other multivariate models can give joint exceedance probabilities for multivariate events in the natural environment. However, the choice of the most appropriate multivariate model may ...not always be evident in the absence of knowledge of dependence structures. A simple nonparametric alternative is to approximate multivariate dependencies using “line mesh distributions”, introduced here as a data-based finite mixture of univariate distributions defined on a mesh of
L
= C(
m
, 2) lines extending through Euclidean
n
-space. That is,
m
data points in
n
-space define a total of
L
lines, where C() denotes the binomial coefficient. The utilitarian simplicity of the method has attraction for joint exceedance probabilities because just the data and a single bandwidth parameter within the 0, 1 interval are needed to define a line mesh distribution. All bivariate planes in these distributions have the same Pearson correlation coefficients as the corresponding data. Marginal means and variances are similarly preserved. Using an example from the literature, a 5-parameter bivariate Gumbel model is replaced with a 1-parameter line mesh distribution. A second illustration for three dimensions applies line mesh distributions to data simulated from a trivariate copula.
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