فيزياء خفض فقد اللاحمل (P0): فولاذ CRGO المعالج بالليزر مقارنة بقلوب السبائك غير المتبلورة

تنقيح المجالات المغناطيسية، ومعادلات تخلف شتاينميتز، والحد من التيارات الدوامية التقليدية، ومعامل البناء (BF)، والخصائص المغناطيسية للشريط غير المتبلور Fe-Si-B.

1. Physics of No-Load Core Losses

No-load core loss (P0) occurs 8,760 hours per year continuously. It consists of hysteresis loss (Ph), classical eddy current loss (Pcl), and anomalous excess loss (Pexc):

P0 = Ph + Pcl + Pexc

2. Mathematical Formulation of Loss Mechanisms

Hysteresis Loss (Steinmetz Empirical Formulation):

Ph = kh · f · Bmax1.6… 2.0 [W/kg]

Classical Eddy Current Loss in Laminations of Thickness d:

Pcl = (π2 · f2 · Bmax2 · d2) / (6 · ρ · D) [W/kg]

Where:

  • f: System frequency (50 Hz or 60 Hz).
  • Bmax: Peak magnetic flux density in Tesla.
  • d: Lamination thickness (0.23 mm for CRGO, 0.025 mm for amorphous ribbon).
  • ρ: Electrical resistivity of core material.
  • D: Mass density of core material.

3. Technical Comparison: CRGO vs Laser-Scribed vs Amorphous

Material PropertyConventional CRGO (M4/M3)Laser-Scribed CRGO (23ZH85)Amorphous Ribbon (Fe-Si-B)
Lamination Thickness (d)0.27 - 0.30 mm0.20 - 0.23 mm0.025 mm (25 μm)
Saturation Flux Density (Bs)2.03 T1.95 - 2.00 T1.56 T
Design Operating Flux (Bop)1.65 - 1.72 T1.55 - 1.65 T1.30 - 1.35 T
Specific Loss @ 1.5 T, 50 Hz0.95 - 1.15 W/kg0.65 - 0.78 W/kg0.18 - 0.22 W/kg
No-Load Loss ReductionBaseline (0%)-25% to -35%-65% to -75%

4. Core Stacking & Building Factor (BF)

The assembled core exhibits higher losses than laboratory Epstein strip samples due to mechanical clamping stresses and joint air gaps:

Pcore_actual = BF · Pepstein · Mcore

Modern step-lap mitred joints (6-7 step overlap with 45° mitre cuts) reduce BF from 1.25 down to 1.08 - 1.12.

*Reference: IEC 60404-8-7; IEC 60076-1; CIGRE Technical Brochure 655.*