Optimal design of single-phase shell-type distribution transformers based on a multiple design method validated by measurements

Evaluation of distribution transformer banks in electric power systems

“…M3 lamination was used for the magnetic material of all transformers (Figure 4). Figures 5 to 8 were generated using a field-validated transformer design program [11]. Figure 5 shows the tendency of three-phase transformers to have less weight than three-phase transformer banks, but for lower power ratings, the opposite is observed, which is depicted with details in Figure 6.…”

“…The main reason behind this finding is related to the higher weight of transformer tank, oil and high-voltage conductor of three-phase transformer over three-phase transformer banks. core mass (kg) P 11 lateral core mass (kg) P 12 central core mass (kg) M Cu high-voltage conductor mass for three-phase transformers three-phase transformer total mass M ta À 3θ tank mass of the three-phase transformer M oil À 3θ mineral oil mass of the three-phase transformer C mat À 3θ material cost of the three-phase transformer uc HV per unit cost of high-voltage conductor ($/kg) uc LV per unit cost of low-voltage conductor ($/kg) uc c per unit cost of core magnetic material ($/kg) uc ta per unit cost of tank steel ($/kg) uc oil per unit cost of mineral oil ($/kg) BP transformer bid price ($) A transformer no-load loss cost rate ($/W) NLL the transformer no-load loss (W) B…”

“…The single-phase case can be easily deduced. Details concerning the calculation of P l1 and P l2 can be found in the studies of Olivares-Galvan et al [11], Harlow [15], Georgilakis [16] and Cogent Power Inc. [14]. The mean turn length is required to calculate the winding resistance and the mass for any given winding (for the calculation of the winding mean turn length, see Rubaai [17] and McLyman [17,18]).…”

“…The transformer design optimisation problem is achieved using a multiple design method that assigns many alternative values to the design variables so as to generate a large number of alternative designs and finally to select the design that satisfies all the problem constraints with the optimum value of the objective function [16,27]. Consequently, this method guarantees the finding of the optimum among the alternative designs considered [11,16,27]. The five design variables and their ranges of variation have been presented in Section 3.2.…”

“…total material cost or total mass) can substitute TOC objective function in Figure 3. In addition to Equations (1a), (1b) and 1c-9(1c)-, the most important formulas can be found in the study of Olivares-Galvan et al [11], which are involved in the transformer design program (shown in the flowchart of Figure 3) to compute quantities such as core mass, no load loss, excitation current, winding mass, load losses and efficiency.…”