Patent ID: 9178455
Filing Date: 2015-11-03
Classification: H02P

Abstract:
1. A method for determining the rotor angle of a synchronous machine, the method comprising: generating a multiplicity of pulse-width-modulated drive signals for the phases of an inverter feeding the synchronous machine depending on a voltage to be fed into the synchronous machine; changing the pulse width modulation frequency of at least one drive signal of the multiplicity of pulse-width-modulated drive signals, with the result that the duration of the switching states of the inverter in which an active voltage phasor is output is extended in order to generate a switching pattern for the phases of the inverter; driving the inverter with the generated switching pattern; determining one or more of neutral point potentials at the neutral point of the synchronous machine during driving of the inverter with the switching pattern; and calculating the rotor angle of the synchronous machine depending on the determined neutral point potentials.