Patent ID: 8233295

Claim:
A method for approximating a peak summed magnitude of a phase voltage waveform comprising voltage vectors including a fundamental voltage vector and a third harmonic voltage vector in a multi-phase system, the method comprising: computing an endpoint value based on a magnitude of a fundamental voltage vector and a magnitude of a third harmonic voltage vector, wherein the endpoint value is the lowest value of the peak summed magnitude for a particular ratio of the magnitude of the fundamental voltage vector to the magnitude of the third harmonic voltage vector; generating a first scaling factor based on a voltage angle difference between an angle of the fundamental voltage vector and an angle of the third harmonic voltage vector; determining, based on the endpoint value and the first scaling factor, an unscaled approximation of the peak summed magnitude of the phase voltage waveform; and scaling the unscaled approximation based on a second scaling factor to generate an approximated peak summed magnitude of the phase voltage waveform that substantially corresponds to the peak summed magnitude of the phase voltage waveform.