Water-cooled high power GTO converters for electric traction

Water-cooled modules for universal use in high power converters have been developed. All electrical parts and the cooling circuit are insulated, allowing a free choice of cooling liquid, preferably natural water as used in diesel engines. A symmetrical snubber circuit with reduced losses in a consequently designed arrangement with low stray inductance results in safe operation at extreme power. Design parameters and restraints for water-cooled designs are explained. Results of measurements on modules and a complete converter are given in this paper