Modified differential evolution method for capacitor placement of distribution systems
ABSTRACT Optimal capacitor placement determines the size and location of capacitors to be installed on a radial distribution feeder. The capacitor placement problem is a combinatorial optimization problem having an objective function composed of power losses and capacitor installation costs subject to bus voltage constraints that are commonly solved by employing mathematical programming methods. This paper presents a new capacitor placement method which employs modified mixed integer hybrid differential evolution (MIHDE) method and sensitivity factor of buses for a given load pattern of distribution systems. The sensitivity factors help reduce the number of alternatives to be examined and MIHDE finds the optimal solution. The proposed approach is demonstrated by employing an application example. Numerical results show that the proposed method can achieve an optimal solution as the exhaustive search can but with much less computational time. This method is especially beneficial for capacitor placement of large distribution systems.
Conference Proceeding: A hybrid method of evolutionary algorithms for mixed-integer nonlinear optimization problems[show abstract] [hide abstract]
ABSTRACT: A hybrid method of evolutionary algorithms, called mixed-integer hybrid differential evolution (MIHDE), is proposed in this study. In the hybrid method, a mixed coding is used to represent the continuous and discrete variables. A rounding operation in the mutation is introduced to handle the integer variables so that the method is not only used to solve mixed-integer nonlinear optimization problems, but also used to solve the real or integer nonlinear optimization problems. The accelerated phase and migrating phase are implemented in MIHDE. These two phases acted as a balancing operator are used to explore the search space and to exploit the best solution. Both examples of mechanical design are tested by the MIHDE. The computation results demonstrate that the MIHDE is superior to other methods in terms of solution quality and robustness propertyEvolutionary Computation, 1999. CEC 99. Proceedings of the 1999 Congress on; 02/1999
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ABSTRACT: A simple optimization procedure for constraint based problems which works without an objective function is described. The absence of an objective function makes the problem formulation particularly simple. The new method lends itself to parallel computation and is well suited for tasks where a family of solutions is required, trade-off situations have to be dealt with or the design center has to be found.IEEE Trans. Evolutionary Computation. 01/1999; 3:22-34.
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ABSTRACT: An algorithm for optimizing shunt capacitor sizes on radial distribution lines with nonsinusoidal substation voltages such that the RMS voltages and their corresponding total harmonic distortion lie within prescribed values is presented. The problem is formulated as a combinatorial optimization problem with inequality constraints. A simple heuristic numerical algorithm that is based on the method of local variations is proposed to determine an optimal solution. An example shows that optimal capacitor sizes found by neglecting the harmonic components may result in unacceptable voltage distortion levelsIEEE Transactions on Power Delivery 05/1990; · 1.52 Impact Factor