Paper Title
Harmonic Filters Planning of Traction System IN Taiwan High Speed Rail

Abstract
This paper presents a method for combining hybrid differential evolution and orthogonal arrays (HDEOA) in the planning of harmonic filters for the traction system of a distributed generation (DG) system with specially connected transformers in unbalanced three-phase power systems. The objective is to minimize total demand distortion of harmonic currents and total harmonic distortion of voltages. An orthogonal array is first conducted to obtain the initial solution set; the set is then treated as the initial sample. Next, the HDEOA method parameters are determined by using matrix experiments with an orthogonal array, in which a minimal number of experiments have an effect that approximates the full factorial experiments. This HDEOA method is then applied to design optimal harmonic filters in a traction system, where both rectifiers and inverters with IGBT are used. From the results of the illustrative examples, the feasibility of the HDEOA to design an optimal passive harmonic filter of traction system is verified and the design approach can greatly reduce the harmonic distortion. Three design cases are compared that V-V connection suppressing the 3rd order harmonic and Le Blanc for the harmonic improvement is superior to those of the V-V and Scott connection. Keywords - Power system harmonic, harmonic filter, hybrid differential evolution, power quality, specially connected transformers.