DC-DC converter

Patent metadata

Field	Value
Publication number	US-8934265-B2
Application number	US-201013806819-A
Country	US
Kind code	B2
Filing date	Jun 25, 2010
Priority date	Jun 25, 2010
Publication date	Jan 13, 2015
Grant date	Jan 13, 2015

Abstract

Provided is a vehicle which enables a highly-efficient DC-DC converter and a highly-efficient power supply to a load, regardless of a power supply amount of to the load. When the power supply amount to a load R1 is a predetermined value or more, a control means 5 implements a first mode for making the switching elements S1 to S4 driven, and when the power supply amount of to the load R1 is the predetermined value or less, the control means 5 implements a second mode, for making the switching elements S3 and S4 stopped in an OFF state, and making only the switching elements S1 and S2 driven.

First claim

The invention claimed is:

1. A DC-DC converter, comprising:
a full bridge circuit, composed of a first switching leg connecting a first and a second switching elements in series, and a second switching leg connecting a third and a fourth switching elements in series, the first and second switching legs being connected in parallel, wherein DC terminals are provided between both ends of the first switching leg and between both ends of the second switching leg, and AC terminals are provided between the series connecting point of the first and the second switching elements, and the series connecting point of the third and the fourth switching elements;
a rectifier circuit having a smoothing reactor;
a first smoothing capacitor connected to a DC power source in parallel and connected to the DC terminals of the full bridge circuit;
a second smoothing capacitor connected to a load in parallel, and connected to a DC terminals of the rectifier circuit;
a primary winding connected to the AC terminals of the full bridge circuit;
a secondary winding connected to an AC terminals of the rectifier circuit;
a transformer for connecting magnetically the primary winding and the secondary winding; and
a control means for controlling the full bridge circuit,
wherein
the first, second, third and fourth switching elements are each composed of a switch, an antiparallel diode connected to the switch in parallel, and a capacitor connected to the switch and the antiparallel diode in parallel, the DC-DC converter having a reactor component inserted between the AC terminals and the primary winding of the full bridge circuit in series;
when power supply amount to the load is predetermined value or more, the control means implements a first mode for making the first, the second, the third and the fourth switching elements driven; and
when power supply amount to the load is predetermined value or less, the control means implements a second mode for making one set of the switching elements of the switching leg at one side composing the first switching leg and the second switching leg stopped, in an OFF state, and for making one set of the switching elements of the switching leg at the other side composing the first switching leg and the second switching leg driven.

2. The DC-DC converter according to claim 1 , wherein:
in implementing the first mode, the control means drives the first, the second, the third and the fourth switching elements in a phase shift system; and
in implementing the second mode, the control means drives one set of the switching elements of the switching leg at the side to drive, in a frequency control system.

3. The DC-DC converter according to claim 1 , wherein
the capacitor, which one set of the switching elements of the switching leg at the side to drive in implementing the second mode has, has a capacitance larger than that of the capacitor which one set of switching elements of the switching leg at the side to be stopped in implementing the second mode has.

4. The DC-DC converter according to claim 1 , wherein a snubber capacitor is connected to each of one set of switching elements of the switching leg at the side stopped in implementing the second mode in parallel.

5. The DC-DC converter according to claim 1 , wherein the antiparallel diode, which one set of the switching elements of the switching leg at the side stopped in implementing the second mode has, has a reverse recovery characteristic slower than that of the antiparallel diode which one set of the switching elements of the switching leg at the side driven in implementing the second mode has.

6. The DC-DC converter according to claim 1 , wherein one set of the switching elements of the switching leg at the side to drive in implementing the second mode has a switching characteristic faster than that of one set of the switching elements of the switching leg at the side to be stopped in implementing the second mode.

7. The DC-DC converter according to claim 1 , wherein one set of the switching elements of the switching leg at the side to drive in implementing the second mode are MOSFETs, and one set of the switching elements of the switching leg at the side to be stopped in implementing the second mode are IGBTs.

8. The DC-DC converter according to claim 1 , wherein one set of the switching elements of the switching leg at the side to drive in implementing the second mode are IGBTs, and one set of the switching elements of the switching leg at the side to be stopped in implementing the second mode are MOSFETs.

9. The DC-DC converter according to claim 1 , wherein the predetermined value includes a first predetermined value and a second predetermined value larger than the first predetermined value, and the control means is configured to switch to a second mode, in the case where a power supply amount to the load is the first predetermined value or less, and is configured to switch to a first mode, in the case where power supply amount to the load is the second predetermined value or more.

10. The DC-DC converter according to claim 1 , wherein the rectifier circuit is provided with a connecting body between one end of the first smoothing reactor and one end of the second smoothing reactor, and a connecting body between one end of the first diode and one end of the second diode, the other end of the first smoothing reactor being connected to the other end of the first diode, and the other end of the second smoothing reactor being connected to the other end of the second diode, wherein AC terminals are provided between the other end of the first diode and the other end of the second diode, and DC terminals are provided between the connecting point of the first and the second smoothing reactors and the connecting point of the first and the second diodes.

11. The DC-DC converter according to claim 1 , wherein the rectifier circuit is provided with a connecting body between one end of the first smoothing reactor and one end of the second smoothing reactor, and a connecting body between one end of the switching element at the first rectifier circuit side and one end of the switching element at the second rectifier circuit side, the other end of the first smoothing reactor being connected to the other end of the switching element at the first rectifier circuit side, and the other end of the second smoothing reactor being connected to the other end of the switching element at the second rectifier circuit side, wherein AC terminals are provided between the other end of the switching element at the first rectifier circuit side and the other end of the switching element at the second rectifier circuit side, and DC terminals are provided between the connecting point of the first and the second smoothing reactors and the connecting point of the switching elements at the first and the second rectifier circuit sides.

12. The DC-DC converter according to claim 1 , wherein the secondary winding is provided with a connecting body between one end of the first secondary winding and one end of the second secondary winding, and the rectifier circuit is provided with the smoothing reactor and the first and the second diodes, one end of the first diode being connected to the other end of the first secondary winding, one end of the second diode being connected to the other end of the second secondary winding; and the other end of the first diode and the other end of the second diode being connected to one end of the smoothing reactor, wherein DC terminals are provided between the connecting point of the first and the second secondary winding and the other end of the smoothing reactor, and AC terminals are provided between one end of the first diode

Assignees

• Hatakeyama Tomoyuki
• Shimada Takae
• Hitachi Ltd

Inventors

• Hatakeyama Tomoyuki
• Shimada Takae

Classifications

• H02M3/24

  by static converters · CPC title

• H02M3/3376 Primary

  with automatic control of output voltage or current · CPC title

• H02M3/33538

  of the forward type (H02M3/3353, H02M3/33569 take precedence) · CPC title

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title

• H02M3/28

  using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC · CPC title