Unit commitment with valve-point loading effect

Valve-point loading affects the input-output characteristics of generating units, bringing the fuel costs nonlinear and nonsmooth. This has been considered in the solution of load dispatch problems, but not in the planning phase of unit commitment. This paper presents a mathematical optimization model for the thermal unit commitment problem considering valve-point loading. The formulation is based on a careful linearization of the fuel cost function, which is modeled with great detail on power regions being used in the current solution, and roughly on other regions. A set of benchmark instances for this problem is used for analyzing the method, with recourse to a general-purpose mixed-integer optimization solver

Determination of optimal tool path in drilling operation using Modified Shuffled Frog Leaping Algorithm

Applications like boilerplates, food-industry processing separator, printed circuit boards, drum and trammel screens, etc. consists of a matrix of a large number of holes. The primary issue involved in hole-making operations is a tool travel time. It is often necessary to find the optimal sequence of operations so that the total processing cost of hole-making operations can be minimized. In this work, therefore an attempt is made to reduce the total tool travel of hole-making operations by applying a relatively new optimization algorithm known as modified shuffled frog leaping for determining the optimal sequence of operations. Modification is made in the existing shuffled frog-leaping algorithm by introducing three parameters with their positive values to widen the search capability of existing algorithms. A case study of the printed circuit board is considered in this work to demonstrate the proposed approach. Obtained results of optimization using modified shuffled frog leaping algorithm are compared with those obtained using particle swarm optimization, firefly algorithm and shortest path search algorithm

Algorithms to Model and Optimize a Stand-Alone Photovoltaic-Diesel-Battery System: An Application in Rural Libya

This paper introduces a new optimum calculation technique for a stand-alone hybrid photovoltaic-diesel-battery system (PDBS), which meets the energy requirements of a small village in southern Libya. The bat algorithm design strategy is applied to reduce the annual cost of the system, taking into consideration the controlled electricity restriction and the optimal numbers of PV panels, diesel generators, and batteries. Comparative tests are performed using MATLAB for the bat algorithm with the grey wolf search algorithm and particle swarm optimization, demonstrating that the bat algorithm determines the optimum size of the PDBS effectively at a lower expense. Results then indicate that, taking into account the reliability characteristics, this has a significant effect on optimum capacity, load supply, and cost

Increasing convergence rate in two-objective optimization of water distribution network with engineering judgment

Background: Water distribution networks (WDNs) are facilities that require massive investment and their optimization is very important. This study aimed to optimization and development of models for promoting WDNs with using engineering judgment. In this method, instead of controlling all system states, it is possible to search the optimal set of options based on engineering judgment and hydraulic and physical status of the system. Thus, the time to solve the optimization problem is greatly reduced, which is very important in widespread networks with many components. The case study was a WDN in western Tehran. Methods: To reduce the calculation size and increase the convergence rate using engineering judgment, the parts of the network where there was no possibility of parallel piping was ignored. For other parts with a low pressure problem, parallel piping was defined. A FMGA and WaterGEMS hydraulic software were used to optimize the WDN. Cost minimization and pressure benefit maximization were the objective functions and the diameters of the pipes were considered to be the decision variables. Results: The results of optimization the network showed that, the cost decreased 89.84% and the pressure in all nodes, except one node, reached within the standard range (26-60 mH20). It included 2387 m of pipe with diameters of 100, 150, 200, 250, 350, 400 and 500 mm. Conclusion: The results of optimization and modification of the network using engineering judgment confirm that the cost decreased significantly and the pressure level in all the nodes increased to above the allowable minimum pressure. Keywords: Water, Judgment, Software, Pressure, Engineerin