Pulse charging of a capacitor

Patent metadata

Field	Value
Publication number	US-12230994-B2
Application number	US-202017596220-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Jun 13, 2019
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

There is provided an apparatus for pulse charging of a load capacitor, the apparatus comprising: a ferrous cored transformer having a primary winding and a secondary winding; a primary circuit connected to the primary winding; a secondary circuit connected to the secondary winding, the secondary circuit comprising the load capacitor; and an uncoupled inductance in the primary circuit or the secondary circuit, the uncoupled inductance reducing the coupling coefficient between the primary circuit and the secondary circuit.

First claim

The invention claimed is:

1. An apparatus for pulse charging of a load capacitor, the apparatus comprising:
a ferrous cored transformer having a primary winding, a secondary winding, and a coupling coefficient between the primary winding and the secondary winding;
a primary circuit connected to the primary winding, the primary circuit configured to carry a first voltage;
a secondary circuit connected to the secondary winding, the secondary circuit comprising the load capacitor, the secondary circuit configured to carry a second voltage having a first resonant peak while the first voltage is non-zero and a second resonant peak while the first voltage is zero; and
an uncoupled inductance in the primary circuit, the uncoupled inductance being magnetically uncoupled from the primary winding and the secondary winding and having a value wherein a coupling coefficient between the primary circuit and the secondary circuit is 0.6 and the coupling coefficient between the primary winding and the secondary winding is greater than 0.6 such that the load capacitor charges on the second resonant peak of the secondary voltage while the first voltage is zero.

2. The apparatus of claim 1 , wherein the uncoupled inductance is in series with the primary winding.

3. The apparatus of claim 1 , wherein the uncoupled inductance is provided by a variable inductor component.

4. A method of pulse charging of a load capacitor, the method comprising:
connecting a primary circuit to a primary winding of a ferrous cored transformer, the primary circuit configured to carry a first voltage;
connecting a secondary circuit to a secondary winding of a ferrous cored transformer, the secondary circuit comprising the load capacitor, the secondary circuit configured to carry a second voltage having a first resonant peak while the first voltage is non-zero and a second resonant peak while the first voltage is zero; and
connecting an uncoupled inductance in the primary circuit, the uncoupled inductance being magnetically uncoupled from the primary winding and the secondary winding and having a value wherein a coupling coefficient between the primary circuit and the secondary circuit is 0.6 and a coupling coefficient between the primary winding and the secondary winding is greater than 0.6 such that the load capacitor charges on the second resonant peak of the secondary voltage while the first voltage is zero.

5. The method of claim 4 , wherein the uncoupled inductance is in series with the primary winding.

6. The method of claim 4 , wherein the uncoupled inductance is provided by a variable inductor component.

7. A method of designing a circuit for pulse charging of a load capacitor, the method comprising:
selecting a ferrous cored transformer having a primary winding, a secondary winding, and a coupling coefficient between the primary winding and the secondary winding, and calculating the mutual inductance between the primary and secondary windings;
determining a secondary circuit resonant frequency; and
identifying a required coupling coefficient for a primary circuit connected to the primary winding and a secondary circuit connected to the secondary winding, the primary circuit configured to carry a first voltage, the secondary circuit comprising the load capacitor and configured to carry a second voltage having a first resonant peak while the first voltage is non-zero and a second resonant peak while the first voltage is zero, and calculating a value of an uncoupled inductance such that the primary and secondary circuits are coupled by the coupling coefficient, wherein the uncoupled inductance is magnetically uncoupled from the primary winding and the secondary winding and has a value wherein the coupling coefficient between the primary circuit and the secondary circuit is 0.6 and the coupling coefficient between the primary winding and the secondary winding is greater than 0.6 such that the load capacitor charges on the second resonant peak of the secondary voltage while the first voltage is zero.

8. The method of claim 7 , wherein calculating the mutual inductance between the primary and secondary windings comprises: identifying the primary inductance, the secondary winding inductance, the coupling coefficient between the primary and secondary windings, and calculating therefrom the mutual inductance between the primary and secondary windings.

9. The method of claim 7 , wherein determining the secondary circuit resonant frequency comprises: determining the secondary winding capacitance, load capacitance and load voltage, and calculating therefrom the secondary circuit resonant frequency.

10. The method of claim 7 , comprising the uncoupled inductance with a variable inductor component.

11. The method of claim 7 , wherein the uncoupled inductance is in series with the primary winding.

Assignees

• Bae Systems Plc

Inventors

• Moore Ian Anthony
• Parker Michael James
• Scott Daniel James
• Toms Stuart James

Classifications

• H02J7/927

  with introduction of pulses during the charging process · CPC title

• H01F38/00 Primary

  Adaptations of transformers or inductances for specific applications or functions · CPC title

• H01F30/00

  Fixed transformers not covered by group H01F19/00 · CPC title

• H03K3/53 Primary

  by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback (H03K3/335 takes precedence) · CPC title

• H01F27/2895

  Windings disposed upon ring cores · CPC title