Energy extraction from the parasitic elements in power converters

Patent metadata

Field	Value
Publication number	US-11929665-B2
Application number	US-202318373590-A
Country	US
Kind code	B2
Filing date	Sep 27, 2023
Priority date	Dec 2, 2016
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

A switching power conversion apparatus for converting power from an input voltage source to a load includes first and second switches connected to a switching node. An inductive element has a magnetizing current connected to the node, and the inductive element is connected to deliver energy via the first and second switches from the input voltage to the load during a succession of power conversion cycles. A capacitance connected to the node resonates with the inductive element to cause parasitic oscillation. A clamp subcircuit across the inductive element contains an auxiliary switch to trap energy and prevent parasitic oscillation, wherein the auxiliary switch is complementary to the first switch. A controlled voltage source injects energy in the inductive element, when the auxiliary switch turns off to discharge the parasitic capacitance by using trapped energy in the inductive element in addition to injected energy from the controlled voltage source.

First claim

What is claimed is:

1. A switching power conversion apparatus, for converting power from an input voltage source to a load, comprising:
a first switch connected to a switching node;
a second switch connected to the switching node, wherein the second switch is turned on after the first switch turns off;
an inductive element having a magnetizing current connected to the switching node, wherein the inductive element is connected to deliver energy via the first and second switches from the input voltage to the load during a succession of power conversion cycles;
a capacitance connected to the switching node wherein the capacitance is configured to resonate with the inductive element during a portion of the power conversion cycles to cause a parasitic oscillation unrelated to the power conversion cycles;
a clamp subcircuit placed across the inductive element containing an auxiliary switch to trap energy in the inductive element and prevent the parasitic oscillation, wherein the auxiliary switch is complementary to the first switch; and
a controlled voltage source, controlled in an amplitude and a duration of the amplitude, to inject energy in the inductive element to control an amplitude of the magnetizing current of the inductive element at a determined level, at a time when the auxiliary switch turns off to discharge the parasitic capacitance to a given voltage by using trapped energy in the inductive element in addition to injected energy from the controlled voltage source.

2. The switching power conversion apparatus of claim 1 , wherein the inductive element comprises a choke.

3. The switching power conversion apparatus of claim 2 , wherein the switching power conversion apparatus is a non-isolated boost converter containing a power switch and a rectifier means, wherein the power switch is the first switch and the rectifier means is a secondary switch.

4. The switching power conversion apparatus of claim 2 , wherein the switching power conversion apparatus is a non-isolated buck converter containing a power switch and a rectifier means, wherein the power switch which is the first switch and the rectifier means is a secondary switch.

5. The switching power conversion apparatus of claim 1 , wherein:
the inductive element comprises a transformer, and the transformer contains a primary winding, at least one secondary winding, and auxiliary windings; and
the clamp subcircuit is placed across the primary winding.

6. The switching power conversion apparatus of claim 5 , wherein the transformer is part of a flyback converter.

7. The switching power conversion apparatus of claim 5 , wherein the transformer is part of a forward converter.

8. The switching power conversion apparatus of claim 5 , wherein the transformer is part of a half bridge converter.

9. The switching power conversion apparatus of claim 5 , wherein the transformer is part of a full bridge converter.

10. The switching power conversion apparatus of claim 1 wherein the inductive element comprises a transformer containing a primary winding, at least one secondary winding, and auxiliary windings, and the clamp subcircuit is placed across the auxiliary winding.

11. The switching power conversion apparatus of claim 10 , wherein the transformer is part of a flyback converter.

12. The switching power conversion apparatus of claim 10 , wherein the transformer is part of a forward converter.

13. The switching power conversion apparatus of claim 10 , wherein the transformer is part of a half bridge converter.

14. The switching power conversion apparatus of claim 10 , wherein the transformer is part of a full bridge converter.

15. A switching power conversion apparatus, for converting power from an input voltage source to a load, comprising:
a first switch connected to a switching node;
a second switch connected to the switching node wherein the second switch is turned on after the first switch turns off;
an inductive element connected to the switching node, wherein the inductive element is connected to deliver energy via the first and second switches from the input voltage to the load during a succession of power conversion cycles;
the switching node is a primary winding of a transformer, the transformer having at least a secondary winding and at least an auxiliary winding;
a current injection circuit containing a current injection switch, a current injection diode, and a current injection voltage source connected across an auxiliary winding, wherein the current injection switch is turned on prior to the first switch turning on and is turned off after the first switch is turned on;
a current injection capacitor connected between a termination of the current injection switch which is not connected to the auxiliary winding and a cathode of the current injection diode;
a capacitance connected to the switching node, wherein the capacitance is configured to resonate with the inductive element during a portion of the power conversion cycles to cause a parasitic oscillation unrelated to the power conversion cycles;
a clamp subcircuit placed across the primary winding containing an auxiliary switch to trap energy in the inductive element and prevent the parasitic oscillation, wherein the auxiliary switch is complementary to the first switch; and
a controlled voltage source to inject energy in the inductive element to control amplitude of a magnetizing current of the inductive element at a determined level, when the auxiliary switch turns off to discharge the parasitic capacitance to a given voltage by using trapped energy in the inductive element in addition to injected energy from the controlled voltage source.

16. The switching power conversion apparatus of claim 15 , wherein the transformer is part of a flyback converter.

17. The switching power conversion apparatus of claim 15 , wherein the transformer is part of a forward converter.

18. The switching power conversion apparatus of claim 15 , wherein the transformer is part of a half bridge converter.

19. The switching power conversion apparatus of claim 15 , wherein the transformer is part of a full bridge converter.

20. A switching power conversion apparatus, for converting power from an input voltage source to a load, comprising:
a first switch connected to a switching node;
a second switch connected to the switching node wherein the second switch is turned on after the first switch turns off;
an inductive element connected to the switching node, wherein the inductive element is connected to deliver energy via the first and second switches from the input voltage to the load during a succession of power conversion cycles;
the switching node is a primary winding of a transformer, the transformer having at least a secondary winding, and having first and second auxiliary windings;
a current injection circuit containing a current injection switch, a current injection diode, and a current injection voltage source connected across the first auxiliary winding, wherein the current injection switch is turned on prior to the first switch turning on and is turned off after the first switch is turned on;
a current injection capacitor connected between a termination of the current injection switch which is not connected to the first auxiliary winding and a cathode of the current injection diode;
a capacitance connected to the switching node, wherein the capacitance is configured to resonate with the inductive element during a portion of the power conversion cycles to cause a parasitic oscillation unrelated to the p

Assignees

• Rompower Tech Holdings Llc

Inventors

• Jitaru Ionel

Classifications

• H02M1/083 Primary

  for the ignition at the zero crossing of the voltage or the current · CPC title

• H02M1/4258

  using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage (H02M1/4241 takes precedence) · CPC title

• H02M3/155

  using semiconductor devices only · CPC title

• H02M3/335

  using semiconductor devices only · CPC title

• H02M3/33553

  with galvanic isolation between input and output of both the power stage and the feedback loop · CPC title