CONTROLLER FOR WOUND-ROTOR INDUCTION MACHINE

摘要

PURPOSE:To shorten the time interval during which a power system is adversely effected by resuming operation of a cycloconverter upon reset of primary winding voltage and controlling the current flowing through an overvoltage suppressing circuit to zero. CONSTITUTION:Upon occurrence of fault on a power system, an overvoltage suppressing circuit 90 functions to prevent an overvoltage from being induced in the secondary winding of an induction machine. Upon reset of the voltage on a source bus line 2, a control circuit 11 outputs a signal (c) if an overvoltage detector 9D provides a signal (a) indicating operation of the overvoltage suppressing circuit 90. A cycloconver control circuit 50 receives the signal (c) and controls the output current from a cycloconverter 3 to be equal to the current flowing through the secondary winding of an induction machine 1. Consequently, current flowing through the overvoltage suppressing circuit 90 drops below a predetermined level and normal reset takes place.