Organizations: ABB Corporate Research Center, Väster˚as, Sweden · Dept. of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy
A staged physics-informed neural network (PINN) is proposed for identifying the inductance, capacitance and parasitic resistances of a DC buck converter from time-domain data. Gradients are released in the order of L to C to rL to rC, a sequence derived from sensitivity analysis. The five-stage schedule recovers L and C to within 5% and the series ESR to 10%, while a three-stage variant attains the same accuracy 11% faster. An 84 factorial sweep confirms that the trained PINN remains accurate for simultaneous 8% perturbations of all four components, achieving a waveform RMSE of 2.6 x 10-2 over 5 ms-an order-of-magnitude better than a simultaneous-training baseline.
Figures & tables
Fig. 1 : Buck converter with series inductor ESR (rL) , switch on-resistance (rDS,on) ,and capacitor leakage (rC) explicitly modeled
Fig. 2 : PINN modeling workflow.
Scenario
Stages of learning
Parasitic inductor resistance ( rL only)
2
Parasitic capacitor resistance ( rC only)
2
Both rL and rC
3
5 *
TABLE I : Sequential-training stages required for each identification scenario
Component Parameter
True Values
Inductor, L
2 mH
Capacitor, C
5 μF
Parasitic Inductor Resistance, rL
0.5 Ω
Parasitic Capacitor Resistance, rC
30 kΩ
TABLE II : Buck Converter Parameter True Values
Setting
Value / Rationale
Optimizer
Adam [β1=0.9,β2=0.999]
Learning rate
1×10−3 during data pre-fit; 1×10−4 for every parameter-release stage
Batch size
Full record (5 001 time-samples, 5 ms, Δt=1\upmu s)
Gradient clip
∥∇θ∥2≤1.0 to avoid spikes when a parameter is unfrozen
Input scaling
z -score on iL , vO , and duty ratio S (mean 0, std 1)
Target scaling
Same z -score applied to i˙L and v˙O ; data-loss weights wi=wv=1
TABLE III : Common hyper-parameters used in both training schedules
Fig. 3 : Stage 1 - True Data vs NN Simulation Plots
Fig. 4 : Stage 1 - True Data vs NN Simulation Plots
Offset (%)
L ( mH )
C ( μF )
rL ( Ω )
rC ( kΩ )
–8
1.84
4.60
0.460
27.6
–6
1.88
4.70
0.470
28.2
–4
1.92
4.80
0.480
28.8
–2
1.96
4.90
0.490
29.4
+2
2.04
5.10
0.510
30.6
+4
2.08
5.20
0.520
31.2
TABLE IV : Parameter-sweep grid used for model-robustness analysis
Figure 9
Fig. 7 : RMSE Plots for Parameter Sweep Grid
Table 11
Fig. 8 : PINN (red) versus truth (blue) for the three best parameter sets.
Department of Mechatronics and Robotics Engineering, Egypt-Japan University of Science and Technology (E-JUST), New Burg El-Arab City, Alexandria, Egypt
Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany · Institute of Electrical Energy Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany