Control circuit for a direct current/three-phase current converter.

摘要

Control circuit for semiconductor components (21-26) of a converter circuit (40) which can be switched on and off to convert direct current (Id) into three-phase current. The converter circuit is connected between a direct-current source and the stator of a synchronous machine (2) having a cylindrical rotor. The control circuit comprises rotor position sensors (52) and also a direct current measuring device (43). The control circuit comprises a computer which is designed to determine the value of the commutation angle ( mu ) of the phase current (i) in the converter at any value of the direct current (Id) on the basis of a model of the synchronous machine (2) which solely takes account of the fundamental harmonic of the phase current (i), the firing angle ( alpha ) of the semiconductor components being set between limits determined for any value of the direct current (Id) by the associated commutation angle ( mu ).