Patent ID: 8704480

Claim:
A method for operation of a synchronous machine including a three-phase polyphase controller, connected to a polyphase power supply system and including at least three semiconductor switching elements which are switched on at specific times, the method comprising: defining a sinusoidal fundamental at a frequency which corresponds to the desired rotation speed of the synchronous machine; defining of two further fundamentals at the same frequency, which are phase-shifted with respect to the first fundamental, wherein a) a first option includes the frequency being equal to the frequency of the power supply system voltage, with the further fundamentals being phase-shifted through 120° and 240° with respect to the fundamental, or b) a second option includes the frequency being equal to half the frequency of the power supply system voltage, with the fundamentals including a phase shift with respect to one another which is not the same as the polyphase phase shift through 120° or 240°, wherein the first and second options for the frequency occur individually or in a time sequence; and selecting and using trigger times for triggering, at which triggering at a same time for two of the phases would cause a current of the same polarity as the fundamental associated with the respective phase, wherein the trigger times occur at a specific trigger angle after the respective zero crossing of the power supply system voltage.