Coil with ferromagnetic core. Co-simulation with LTspice

QuickField simulation example

Charged capacitor is connected to the coil. Coil is represented by inductor L1 connected in series with resistor R1.

Problem Type
Axisymmetric problem of DC magnetics

Geometry

Electric circuit schematics:
Nonlinear coil circuit LTSpice

Given
Capacitor value C1 = 100 uF
Capacitor initial voltage V_C1 = 100 V
Coil number of turns n = 500
Coil resistance value R1 = 4.5 Ohm
Ferromagnetic core permeability μ - B(H) curve:

Task
Calculate transient current in the electric circuit.

Solution
QuickField calculates Flux linkage vs. Current characteristic of the coil. The series calculations are automated using LabelMover parametric tool.
The Flux linkage vs. Current characteristic is used in LTspice circuit simulator to define inductor L1 behavior.

Result:
Measured flux linkage (per single turn) and total winding current in QuickField
Coil magnetic flux linkage

Measured in QuickField		Data for LTspice		Inductance, `L` = (Φ/`I`)·`n`² [mH]
Total winding current, `I` [A]	Flux linkage per turn, Φ [mWb]	Conductor current, `I` / `n` [A]	Winding flux linkage, `n`·Φ [mWb]	Inductance, `L` = (Φ/`I`)·`n`² [mH]
500	0.00518	1	2.59	2.59
1000	0.0104	2	5.18	2.59
1500	0.0154	3	7.70	2.57
2000	0.0192	4	9.60	2.40
2500	0.0216	5	10.8	2.16
3000	0.0236	6	11.8	1.97
3500	0.0256	7	12.8	1.83
4000	0.0274	8	13.7	1.71
4500	0.0292	9	14.6	1.62
5000	0.0210	10	15.5	1.55
5500	0.0328	11	16.4	1.49
6000	0.0345	12	17.2	1.44
6500	0.0362	13	18.1	1.39
7000	0.0379	14	19.0	1.35
7500	0.0396	15	19.8	1.32
8000	0.0413	16	20.7	1.29

Capacitor voltage and coil current in time calculated by LTspice
coil simulation

*LTspice is an electronic circuit simulation software by Linear Technology (LTC).

View simulation report in PDF
Download simulation files (files may be viewed using any QuickField Edition).