Safe and time-optimized power transfer between two induction loads supplied by a single generator

The paper deals with the problem of transferring power between different induction loads supplied by the same current generator, in as short a time as possible. In the reference solution, the system is completely stopped: it needs a long time for the current to reach zero and, afterwards, its new value, because the DC link inductance must be demagnetized and remagnetized; moreover an auxiliary starter is needed. In the proposed solution, the input of the current inverter is short-circuited whenever a transfer must be performed; the inductance remains magnetized and the current at the output of the inverter varies very quickly. The transfer time is minimal, and no starter is needed; the specific inverter control laws used to insure natural commutation are described. The paper also, presents control models of the system, obtained by using the first harmonic modeling method