Semi-direct variable speed drive with N+1 power availability

摘要

SEMI-DIRECT VARIABLE SPEED DRIVE WITH N+1 POWER AVAILABILITY Abstract A system for controlling a speed of each of N variable speed motors (M I-M3) with a drive voltage is disclosed, where N is an integer equal to or greater than 1. The system includes (N+1) generators (G I -G4) and a switching arrangement (205) configured to directly couple, in a one-to-one relation, the N variable speed motors (M1-M3) to the (N+1) generators (GI-G4) so that any one of the N variable speed motors (MI-M3)is capable of operating in at least a first mode and a second mode. In the first mode the any one of the N variable speed motors (Ml -M3) is driven with the drive voltage generated by a first generator of at least two of the (N+ 1) generators (G I -G4), and in the second mode the any one of the N variable speed motors (Ml-M3) is driven with the drive voltage generated by a second generator of the at least two of the (N+ 1) generators (G 1 -G4). C3) rN ( U