Axial Flux Studio / Field guide
Current and drive conventions
Motor-phase RMS, controller limits and why battery amps differ.
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Rated current describes a dutyTranslate controller specifications carefullyVoltage and switching are separate constraintsPeak is not RMS.
RMS = peak ÷ √2. This conversion applies to a sinusoidal phase current, not battery current or an unspecified controller limit.
01Rated current describes a duty
Rated motor current is entered in A RMS per motor phase. Together with rated shaft speed, it describes the intended operating point. It is not, by itself, a thermally established continuous motor rating.
Keep the motor operating target separate from the controller’s continuous motor-phase RMS limit. A controller ceiling can make the target infeasible; it must not silently replace the current the machine requires.
02Translate controller specifications carefully
For an explicitly sinusoidal phase waveform, peak current divided by √2 gives RMS current. The drive helper previews this conversion before an explicit Apply action.
Battery/DC current, an unspecified “max amps” figure, Iq from an undocumented convention and timed burst current cannot safely be treated as continuous phase RMS current. Delta line current and winding current also differ; confirm the connection and the controller’s definition before entering a value.
03Voltage and switching are separate constraints
DC bus voltage and modulation determine available motor voltage. They do not increase the current rating. No-load back-EMF is a useful first check, but loaded feasibility also involves resistance, inductance, current angle and speed.
The PWM ripple loss setting concerns the motor ripple model. It is not a prediction of controller semiconductor losses. Review map-based capability and thermal assumptions before claiming a continuous operating envelope.