Models
Simulation of Saturation with CM-Cores
In this simulation, two Common-Mode Cores (CM) are shown - the left model has a purely linear behavior, while the right model simulates the saturation behavior of a nanocrystalline material
Both cores also show an equal frequency behavior, which was also modeled to be similar to nanocrystalline material
The diagram shows the current over time - blue for the Linear CM-Core - red for the Non-Linear-CM core
Defining the start of saturation at 10% deviation from the linear behavior, the saturation current here is just over 1 A
Inverter simulation with Linear CM-Core inside the HV-Filter
0% is set as modulation (zero vector) - this results in the highest CM currents through the magnet core
Inverter simulation with Non-Linear CM-Core inside the HV-Filter
Apart from the magnetic core, the circuit is unchanged
Current spikes through one Y-Capacitor (Cy1) The CM current through the magnet core is the sum of both Y-C
Current spikes through one Y-Capacitor (Cy1) Doubling the battery voltage, doubles the amplitude of the current spikes
Current spikes through a Y-Capacitor (Cy1) With the Non-Linear Core, the current spikes have increased by about 30%
That's about the maximum current for the non-linear core - with barely acceptable inductance reduction
At twice the battery voltage, the amplitude of the current spikes increases by a factor of 10 with the Non-Linear Core
The current spikes have now increased dramatically
Voltage spikes at the Artificial Network (BNN = LISN) with 250 V battery voltage and Linear Magnetic Core
Voltage spikes at the Artificial Network (BNN = LISN) with 250 V battery voltage and Non-Linear Magnetic Core
Voltage spikes at the Artificial Network (BNN = LISN) with 500 V battery voltage and Linear Magnet Core
Voltage spikes at the Artificial Network (BNN = LISN) with 500 V battery voltage and Non-Linear Magnet Core
Noise level at BNN (=LISN) 250 V Linear Magnet Core
Noise level at BNN (=LISN) 250 V Non-Linear Magnet Core
Noise level at BNN (=LISN) 500 V Linear Magnet Core
Noise level at BNN (=LISN) 500 V Non-Linear Magnet Core
Results at the Artificial Network (BNN = LISN):
Conclusion
With the models shown here, CM-Cores and CM-Chokes can be fully mapped in all relevant properties - both with the desired Frequency Characteristics, as well as with the desired Saturation Behavior
Thus, e.g. HV-Filters can be designed and tested to the limit of their ampacity - and beyond, e.g. to investigate the consequences in case of failure
At 250 V, the noise spectrum with the non-linear magnetic core is only slightly different than with the linear core. The deviation from the linear behavior is only 30%.
At 500 V, however, the noise spectrum with the non-linear magnetic core is significantly different than with the linear core. The deviation from the linear behavior is here about factor 10.
© Ingenieurbüro Lindenberger 8447