Development of a 1.2MVA active front end using parallel industrial units

Danfoss Drives A/S has developed a 1.2 MVA Active Front End (AFE). The purpose with this development was to realize a high power AFE as a study object. Secondly the AFE was integrated into a new dynamometer and engaged in testing of high power motor inverters in an engineering laboratory environment. The AFE was used to supply power to a 1500 HP adjustable speed drive used for the dynamometer. The development was made with tight constraints: A limited time frame was available, and the design chosen must assure immediate successful operation. The scope of this paper is to present some of the considerations done during the design phase and to present the achieved system performance of the final system.