A reference space vector (formed by real part = cosine and imaginary part = sine) of length √2*RMS and frequency 2 Hz is applied. The resulting switching patterns are applied to a three-phase twolevel bridge with switching frequency 100 Hz, fed by DC voltage = √2*√3*1 where 1 is the theoretical maximum voltage from terminal to neutral. The resulting voltages with reference to midpoint of the DC voltage are measured.
The RMS of the first harmonic of the first of these voltages is calculated. Please note that the value of the first harmonic is valid after the first period (i.e. 0.5 s).
Furthermore, these three voltages are transformed to the corresponding space phasor. Note that the zero component is not zero, indicating the shift of the neutral with respect to the midpoint of the DC voltage.
The space phasor is rotated to the coordinate system rotating with 2*π*2 Hz. To suppress the influence of switching, real and imaginary part of the rotated phasor are filtered. The polar representation of this rotated and filtered phasor are calculated.
Please note that the filter has a settle time depending on the filter parameters.