Designing current compensated inductors

One Phase Common Mode Choke in a 50Hz net for suppressing 50kHz current harmonic

• Set inductance of both in series connected windings at the peak value of the current Ic (Ic = (Ic1 - Ic2)/2 ~ (0.01-0.05) x Iload
• Set the compensated harmonics of the thermal current .Note that the sign "+" marks the compensated current harmonics.
• Set the other harmonics of the thermal current which are not compensated without the sign "+".
• Select the differential inductance : L-Type = 4
• Select Cu round wire: Wire = 0
• The frequency of the first harmonic is 50Hz
• Set the Q-factor in order to limit the resistive voltage drop of the compensated current, the temperature rise and the criterion = 0
• Select ferrite with a good reverse permeability.
• Select suitable core family and the gap positions

• Control the value of inductance
• Manufacture 2 insulated, full layer windings, each with 50% of the calculated turns. Do not use double section bobbin

• Check the core construction with Gap=0
• Set the current in the LI-point higher and Press Ctrl+L to see the diagram Inductance vs. Current

• In order to calibrate the choke, connect both windings in series on the calculated calibration AC-voltage (rms value) with the calibration frequency (normally 50Hz or 60Hz) and then vary the gap until you get the calculated calibration AC-current (rms value).

Three Phase Common Mode Choke with a one phase core in a 50Hz symmetrical net for suppressing 5000Hz unsymmetrical current harmonics

• Set inductance of three in series connected windings at the peak value of the current 2 x Ico (Ico ~ (0.01-0.05) x Iload
• Set the compensated harmonics of the thermal current .Note that the sign "+" marks the compensated current harmonics.
• Set the other harmonics of the thermal current which are not compensated without the sign "+".
• Select the differential inductance : L-Type = 4
• The frequency of the first harmonic is 50Hz
• Set the Q-factor in order to limit the resistive voltage drop of the compensated current, the temperature rise and the criterion = 0
• Select grain oriented steel.
• Select suitable one phase core family and the gap positions

• Control the value of inductance
• Manufacture 3 insulated, full layer windings, each with 1/3 of the calculated turns.

• Check the core construction with Gap=0
• Set the current in the LI-point higher and Press Ctrl+L to see the diagram Inductance vs. Current

• In order to calibrate the choke, connect all windings in series on the calculated calibration AC-voltage (rms value) with the calibration frequency (normally 50Hz or 60Hz) and then vary the gap until you get the calculated calibration AC-current (rms value).

Drainage Choke between 2 rectifiers

• Set inductance of both windings in series at approx. 5-10% of the nominal current Id/2
• Select the differential inductance : L-Type = 4
• Select Cu flat wire or foil with layer insulation: Wire = 3 or 6
• The frequency of the first harmonic is 150Hz
• Set the rms values of the harmonics of the thermal current: Note that the sign "+" marks the compensated current harmonics.
• Set the temperature rise
• Select cold rolled steel.
• Set Gap = 1 and Core Assembly = 2 or better
• Select suitable core family (UI)

• Control the value of inductance

• Set the current in the LI-point higher and Press Ctrl+L to see the diagram Inductance vs. Current

• In order to calibrate the choke, connect both in series windings on the calculated calibration AC-voltage (rms value) with the calibration frequency (normally 50Hz or 60Hz) and then vary the gap until you get the calculated calibration AC-current (rms value).

Drainage Choke between 2 phases of inverters

• Set inductance of both windings in series at approx. 5-10% of the nominal current Iout/2
• Select the differential inductance : L-Type = 4
• Select Cu flat wire or foil with layer insulation: Wire = 3 or 6
• The frequency of the first harmonic is 50Hz
• Set the rms values of the harmonics of the thermal current: Note that the sign "+" marks the compensated current harmonics.
• Set the temperature rise
• Select cold rolled steel.
• Set Gap = 1 and Core Assembly = 2 or better
• Select suitable core family (UI)

• Control the value of inductance

• Set the current in the LI-point higher and Press Ctrl+L to see the diagram Inductance vs. Current

• In order to calibrate the choke, connect both in series windings on the calculated calibration AC-voltage (rms value) with the calibration frequency (normally 50Hz or 60Hz) and then vary the gap until you get the calculated calibration AC-current (rms value).