Hall Angle Offset
Minimum AC input voltage at full output power
This parameter specifies the angle offset between the rotor flux and the hall angle. The alignment of the hall angle signal with the rotor flux depends on the mechanical alignment of the hall sensors within the stator winding. The hall sensor offset parameter allows adjustment to the hall angle alignment.
The MCE controller defines the 0 deg rotor angle at the negative zero crossing of the U phase back EMF. At the correct mechanical alignment, the DH_1 transition with DH_2 low and DH_3 high should align at the peak of the UV line back EMF. In the case of analog Hall sensors, the 120 deg rotor angle alignment is with the AH_U zero crossing at AH_V negative polarity.
The Hall Angle Offset can be determined by measuring the electrical angle between the DH_1 transition or AH_U zero crossing and positive zero crossing of the UV line back EMF and subtracting 90 deg.
Diagram: Hall Angle Offset Measurement
The diagram illustrates the relationship between motor back EMF, digital and analog Hall sensor signals, and the resulting Hall Angle, with a focus on determining the Hall Angle Offset. It comprises five vertically aligned plots against a common time axis (t).
- Motor Back EMF (U Phase): The uppermost plot displays the sinusoidal waveform of the U phase back EMF, labeled `eu`. A dashed line indicates the zero-crossing point.
- Line to Line Back EMF: The second plot shows the line-to-line back EMF waveform, labeled `e_uv`. This waveform is phase-shifted relative to the U phase EMF. Key angular references of 90° and 120° are marked. A segment labeled "Offset meas" is also indicated.
- Digital Hall Sensor Signals (DH1, DH2, DH3): The third plot presents three distinct digital signals (DH1, DH2, DH3) as square waves. These signals represent the outputs of digital Hall sensors and their transitions align with specific points in the EMF waveforms.
- Analog Hall Sensor Signals (AH_U, AH_V): The fourth plot shows two sinusoidal analog Hall sensor signals, AH_U and AH_V, which are phase-shifted. A segment labeled "Hall_Angle_Offset" is depicted between specific points on these signals.
- Hall Angle: The bottommost plot illustrates the calculated Hall Angle as a sawtooth-like waveform. It sweeps through a range of angles, with horizontal lines marking reference points at 0° and -120°. Blue dots highlight specific temporal points on this angle waveform.
The text explains that the Hall Angle Offset is determined by measuring the electrical angle between the DH_1 transition or the AH_U zero crossing and the positive zero crossing of the UV line back EMF, followed by subtracting 90 degrees.
