AFPM Core Efficiency Optimization
Compare core-loss data at your design point, then use the evidence and limits below to decide what needs validation. The tool starts with operating inputs and keeps material loss assumptions explicit.
Request an engineering reviewPublished September 23, 2026 · Sources reviewed October 1, 2026
What an efficiency review should establish
Method: compare losses at a defined point
The calculator derives the fundamental electrical frequency from synchronous speed and total poles. Material loss must then come from test or supplier data at that frequency and the same peak flux density. No Steinmetz coefficients or generic crossover threshold are assumed.
- 1
Set the operating point
Enter speed, total poles, and peak flux density.
- 2
Match loss data
Use steel and SMC data at the same frequency and peak flux density.
- 3
Compare entered W/kg
The tool compares only the values and conditions you provide.
- 4
Validate the design
Check waveform, test method, geometry, process, and temperature.
Published data: useful for screening, not direct ranking
Supplier data is tied to a grade and test specimen. The examples below show why a loss value needs its conditions attached; the numbers are not a head-to-head AFPM core result.
| Decision dimension | Electrical steel example | SMC example | Interpretation |
|---|---|---|---|
| Supplier loss data example | M270-35A: maximum 2.70 W/kg at 1.5 T and 50 Hz for the 0.35 mm grade. Supplier data | Somaloy 700 1P: 9.9 W/kg at 1.5 T and 50 Hz in the cited data sheet; its test specimen and process are specified there. Supplier data | These published examples use different specimen and process conditions; do not compare them as a material ranking. |
| Measurement context | IEC 60404-3 covers AC magnetic-property measurement of electrical-steel sheet and strip with a single-sheet tester at power frequencies. IEC scope | Use the specific SMC grade data sheet and its stated specimen, compaction, heat-treatment, and test method. Example data sheet | Material-sheet measurements do not automatically represent a finished AFPM core. |
| Design decision | Assess the selected grade, lamination thickness, cutting and stacking route, insulation, and the actual 2D or 3D flux path. | Select a grade against both magnetic and mechanical requirements; the SMC product family has different loss/permeability trade-offs. Höganäs product range | Choose from matched component or machine evidence, not a universal frequency threshold. |
Values and product availability can change. The cited supplier sheets are the source for each stated grade and test condition; request current data for a production decision.
A practical AFPM core validation sequence
- 1
Map the duty cycle
Record speed, torque, electrical frequency, flux waveform, and time at each operating region.
- 2
Screen candidate data
Compare grade-specific loss curves only where frequency, flux density, and test conditions overlap.
- 3
Check the core and process
Review flux path, saturation margin, geometry, manufacturing route, assembly stress, cooling, and cost.
- 4
Validate representative hardware
Measure a representative core or machine and reconcile the result with the loss model before locking the design.
An AFPM prototype study reported that optimization and control choices changed iron loss by around 14% between its tested configurations. That result belongs to the studied prototypes; it is evidence to evaluate topology and control together, not a general performance promise. Read the IEEE study.
Apply the comparison to your AFPM design
For a design-specific review, share the operating point, core geometry, candidate loss data, and validation target.
Request a design reviewLimits and risks to resolve before selection
AFPM efficiency FAQ
What does the comparison tool calculate?
It calculates fundamental electrical frequency from speed and total pole count, checks whether both entered loss data sets match that frequency and the entered peak flux density, and compares the two W/kg values. It does not predict losses from material names.
How is AFPM electrical frequency calculated?
For synchronous operation, fundamental electrical frequency in hertz is mechanical speed in RPM multiplied by the total number of poles, then divided by 120. This does not include inverter harmonics or local space-harmonic effects.
Why must both loss values use the same frequency and flux density?
Specific core loss changes with magnetic frequency and flux density. Comparing values measured at different operating points can make the apparent material difference meaningless; use matching curves or test data instead of interpolating with this tool.
Does lower core loss mean higher motor efficiency?
It indicates lower entered core loss for the stated comparison point only. Motor efficiency also depends on copper, magnet, mechanical, inverter, cooling, and operating-cycle losses, plus how the core behaves in the assembled machine.
Is SMC always better at high frequency?
No universal crossover frequency applies to every topology, grade, waveform, and process. Compare the specific steel and SMC data over the intended operating range, then validate the selected design in a representative component or machine.
Can supplier sheet data be used as finished-core performance?
Use it for screening, with the supplier test conditions attached. Cutting, compaction, heat treatment, assembly stress, local flux waveform, and geometry can change finished-part behavior; verify critical values on representative samples.
What should an engineering review include?
Share the speed and torque map, pole/slot geometry, flux-density waveform, core drawings, candidate grades, process route, cooling boundary conditions, and test targets. Include loss curves with frequency, induction, waveform, and specimen details.
Related AFPM engineering topics
Sources and evidence limits
Page reviewed October 1, 2026. Supplier values describe named products and stated test conditions. They do not establish an unmeasured production-core result or guarantee an efficiency gain.
- Höganäs, Somaloy® 700 1P material data sheet
Supplier loss curves and sample conditions for a specific SMC grade and compaction route; not a universal SMC value.
- thyssenkrupp Steel, powercore® A non-oriented electrical steel
Supplier maximum core-loss data for named grades, thicknesses, flux densities, and frequencies.
- IEEE Transactions on Energy Conversion, AFPM SMC iron-loss analysis
AFPM prototype study showing that topology and control choices affect measured and modeled iron loss.
- IEC 60404-3:2022
Measurement method for AC magnetic properties of electrical-steel sheet and strip using a single-sheet tester at power frequencies.
- Höganäs, coated powders for electromagnetic applications
Product-family positioning: grades address different combinations of loss, permeability, and mechanical requirements.
Need a design-specific comparison?
Share your operating points, core geometry, candidate material data, and validation target for an engineering review of an AFPM core or SMC stator program.
Discuss your AFPM core