US-20260128680-A1 - ELECTRIC POWER CONVERSION APPARATUS

US20260128680A1US 20260128680 A1US20260128680 A1US 20260128680A1US-20260128680-A1

Abstract

An electric power conversion apparatus includes: a first electric power terminal; an inductor; a capacitor; a switching circuit including a first switching device and a second switching device; a transformer including a first winding and a second winding; a rectifying circuit including a third switching device and a fourth switching device; a smoothing circuit; a second electric power terminal; and a control circuit configured to control operations of the switching circuit and the rectifying circuit by performing first control in which a first operation, a second operation, a third operation, a fourth operation, a fifth operation, and a sixth operation are performed in this order repeatedly.

Inventors

Ryosuke Ushikubo

Assignees

TDK CORPORATION

Dates

Publication Date: 20260507
Application Date: 20251028
Priority Date: 20241106

Claims (6)

1 . An electric power conversion apparatus comprising: a first electric power terminal including a first coupling terminal and a second coupling terminal; an inductor having a first end coupled to the first coupling terminal and a second end coupled to a first node; a capacitor having a first end coupled to the first coupling terminal or the second coupling terminal and a second end coupled to a second node; a switching circuit including a first switching device and a second switching device, the first switching device having a first end coupled to a third node and a second end coupled to the second coupling terminal, the second switching device having a first end coupled to the second node and a second end coupled to the third node; a transformer including a first winding and a second winding, the first winding having a first end coupled to the first node and a second end coupled to the third node, the second winding having a first end coupled to a fourth node and a second end coupled to a fifth node; a rectifying circuit including a third switching device and a fourth switching device, the third switching device having a first end coupled to the fifth node and a second end coupled to a sixth node, the fourth switching device having a first end coupled to the fourth node and a second end coupled to the sixth node; a smoothing circuit coupled to the fourth node and the sixth node; a second electric power terminal coupled to the smoothing circuit; and a control circuit configured to control operations of the switching circuit and the rectifying circuit by performing first control in which a first operation, a second operation, a third operation, a fourth operation, a fifth operation, and a sixth operation are performed in this order repeatedly, wherein the first operation includes causing the first switching device, the second switching device, the third switching device, and the fourth switching device to be off, the second operation includes causing the second switching device and the fourth switching device to be on and causing the first switching device and the third switching device to be off, the third operation includes causing the third switching device and the fourth switching device to be on and causing the first switching device and the second switching device to be off, the fourth operation includes causing the third switching device to be on and causing the first switching device, the second switching device, and the fourth switching device to be off, the fifth operation includes causing the first switching device and the third switching device to be on and causing the second switching device and the fourth switching device to be off, and the sixth operation includes causing the third switching device to be on and causing the first switching device, the second switching device, and the fourth switching device to be off.
2 . The electric power conversion apparatus according to claim 1 , wherein the electric power conversion apparatus is configured to, in a time period during which the control circuit is performing the third operation, allow a first voltage across the first switching device to change from a voltage higher than a second voltage between the first coupling terminal and the second coupling terminal to a voltage lower than the second voltage.
3 . The electric power conversion apparatus according to claim 1 , wherein the electric power conversion apparatus is configured to: in the second operation, allow current to flow through the smoothing circuit, the sixth node, the fourth switching device, and the fourth node in this order along a first circulation path including the smoothing circuit, the sixth node, the fourth switching device, and the fourth node, and to thereafter flow in reverse order along the first circulation path; and in the fifth operation, allow current to flow through the smoothing circuit, the fourth node, the second winding, the fifth node, the third switching device, and the sixth node in this order along a second circulation path including the smoothing circuit, the fourth node, the second winding, the fifth node, the third switching device, and the sixth node, and to thereafter flow in reverse order along the second circulation path.
4 . The electric power conversion apparatus according to claim 1 , wherein the control circuit is configured to: perform the first control when a current value of a current flowing through the second electric power terminal is greater than a first threshold; and when the current value of the current flowing through the second electric power terminal is less than or equal to the first threshold, control the operations of the switching circuit and the rectifying circuit by performing second control in which a seventh operation, an eighth operation, a ninth operation, a tenth operation, an eleventh operation, and a twelfth operation are performed in this order repeatedly, the seventh operation includes causing the first switching device, the second switching device, the third switching device, and the fourth switching device to be off, the eighth operation includes causing the second switching device and the fourth switching device to be on and causing the first switching device and the third switching device to be off, the ninth operation includes causing the second switching device to be on and causing the first switching device, the third switching device, and the fourth switching device to be off, the tenth operation includes causing the third switching device to be on and causing the first switching device, the second switching device, and the fourth switching device to be off, the eleventh operation includes causing the first switching device and the third switching device to be on and causing the second switching device and the fourth switching device to be off, and the twelfth operation includes causing the third switching device to be on and causing the first switching device, the second switching device, and the fourth switching device to be off.
5 . The electric power conversion apparatus according to claim 4 , wherein the control circuit is configured to, when the current value of the current flowing through the second electric power terminal falls below a second threshold less than the first threshold, control the operations of the switching circuit and the rectifying circuit by performing third control that causes the first switching device and the second switching device to alternately turn on and causes the third switching device and the fourth switching device to remain off.
6 . The electric power conversion apparatus according to claim 5 , wherein the control circuit is configured to, when the current value of the current flowing through the second electric power terminal falls below a third threshold less than the second threshold, control the operations of the switching circuit and the rectifying circuit by performing fourth control in which the third control is performed intermittently.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority from Japanese Patent Application No. 2024-194631 filed on Nov. 6, 2024 and Japanese Patent Application No. 2025-158981 filed on Sep. 25, 2025, the entire contents of each of which are hereby incorporated by reference. BACKGROUND The disclosure relates to an electric power conversion apparatus that converts electric power. Examples of an electric power conversion apparatus include what is called an active clamp forward DC-DC converter. For example, reference is made to International Publication No. WO 2004/001937. SUMMARY An electric power conversion apparatus according to one embodiment of the disclosure includes a first electric power terminal, an inductor, a capacitor, a switching circuit, a transformer, a rectifying circuit, a smoothing circuit, a second electric power terminal, and a control circuit. The first electric power terminal includes a first coupling terminal and a second coupling terminal. The inductor has a first end coupled to the first coupling terminal and a second end coupled to a first node. The capacitor has a first end coupled to the first coupling terminal or the second coupling terminal and a second end coupled to a second node. The switching circuit includes a first switching device and a second switching device. The first switching device has a first end coupled to a third node and a second end coupled to the second coupling terminal. The second switching device has a first end coupled to the second node and a second end coupled to the third node. The transformer includes a first winding and a second winding. The first winding has a first end coupled to the first node and a second end coupled to the third node. The second winding has a first end coupled to a fourth node and a second end coupled to a fifth node. The rectifying circuit includes a third switching device and a fourth switching device. The third switching device has a first end coupled to the fifth node and a second end coupled to a sixth node. The fourth switching device has a first end coupled to the fourth node and a second end coupled to the sixth node. The smoothing circuit is coupled to the fourth node and the sixth node. The second electric power terminal is coupled to the smoothing circuit. The control circuit is configured to control operations of the switching circuit and the rectifying circuit by performing first control in which a first operation, a second operation, a third operation, a fourth operation, a fifth operation, and a sixth operation are performed in this order repeatedly. The first operation includes causing the first switching device, the second switching device, the third switching device, and the fourth switching device to be off. The second operation includes causing the second switching device and the fourth switching device to be on and causing the first switching device and the third switching device to be off. The third operation includes causing the third switching device and the fourth switching device to be on and causing the first switching device and the second switching device to be off. The fourth operation includes causing the third switching device to be on and causing the first switching device, the second switching device, and the fourth switching device to be off. The fifth operation includes causing the first switching device and the third switching device to be on and causing the second switching device and the fourth switching device to be off. The sixth operation includes causing the third switching device to be on and causing the first switching device, the second switching device, and the fourth switching device to be off. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the specification, serve to explain the principles of the disclosure. FIG. 1 is a circuit diagram illustrating a configuration example of an electric power conversion apparatus according to one example embodiment of the disclosure. FIG. 2 is an explanatory diagram illustrating an example of operation modes of the electric power conversion apparatus illustrated in FIG. 1. FIG. 3 is a timing waveform diagram illustrating an operation example of the electric power conversion apparatus illustrated in FIG. 1. FIG. 4A is an explanatory diagram illustrating an operation state of the electric power conversion apparatus illustrated in FIG. 1. FIG. 4B is an explanatory diagram illustrating another operation state of the electric power conversion apparatus illustrated in FIG. 1. FIG. 4C is an explanatory diagram illustrating another operation state of the electric power conversion apparatus illustrated in FIG. 1. FIG. 4D is an explanatory diagram illustrating another operation state of the electric power conversion apparatus illustrated