Optimization and Computer Aided Design of Special Transformers

摘要

The process of optimal design of special transformers like the resistance welding transformer (RWT) or combined current-voltage instrument transformer (CCVIT) is a complex procedure. The both design objects are complex non-linear electromagnetic systems, as described in [20] and [21]. The procedure of optimal design begins with thorough study of the initial design of the both transformers. For the purpose of the optimization the mathematical models of the transformers are defined. A thorough finite element (FEM-3D) analysis of the electromagnetic parameters is performed, [20, 21] and the derived results are input data in the genetic algorithm (GA) optimal design procedure. The CCVIT is a complex electromagnetic device with two measurement cores: voltage measurement core (VMC) and current measurement core (CMC) with four windings and two magnetic cores with mutual non-linear electromagnetic influence in one housing (VMC ratio 20000V/^3 : wov/^3 and CMC ratio 100 A: 5 A). The resistance welding transformer has the following rated data: primary voltage 380 V; secondary no-load voltage (1.41 - 4.63) V; conventional power 24 kVA; rated frequency 50 Hz; thy-ristor controlled switching; number of primary tap positions 9. The transformer is a single phase with shell type core.