Bidirectional dc/dc converter, and bidirectional power converter

Patent metadata

Field	Value
Publication number	US-2016149502-A1
Application number	US-201414899808-A
Country	US
Kind code	A1
Filing date	Jul 1, 2014
Priority date	Jul 2, 2013
Publication date	May 26, 2016
Grant date	—

Abstract

In a discharging operation of a vehicle storage battery, a controller switches between a full-wave rectification operation of full-wave rectify a voltage across a second winding while maintaining a second short circuit in an open state, and a full-wave voltage doubling rectification operation of full-wave voltage doubling rectify a voltage across second winding while maintaining second short circuit in a closed state, based on magnitude relationship between DC voltage across first terminals and DC voltage across second terminals. In a charging operation, controller switches between a full-wave rectification operation of full-wave rectify a voltage across a first winding while maintaining a first short circuit in an open state, and a full-wave voltage doubling rectification operation of full-wave voltage doubling rectify a voltage across first winding while maintaining first short circuit in a closed state, based on magnitude relationship between DC voltage across first terminals and DC voltage across second terminals.

First claim

1 . A bidirectional DC/DC converter configured to perform bidirectional voltage conversion in which an operation is switched between a first operation of outputting a second DC voltage resulting from DC/DC conversion of a first DC voltage received through first terminals, through second terminals, and a second operation of outputting a fourth DC voltage resulting from DC/DC conversion of a third DC voltage received through the second terminals, through the first terminals, the bidirectional DC/DC converter comprising:
a first switching circuit constituted by a series circuit of first and second switching elements connected between the first terminals and a series circuit of third and fourth switching elements connected between the first terminals; a first winding of a transformer connected between a connection point of the first and second switching elements and a connection point of the third and fourth switching elements; a second switching circuit constituted by a series circuit of fifth and sixth switching elements connected between the second terminals and a series circuit of seventh and eighth switching elements connected between the second terminals; a second winding of the transformer connected between a connection point of the fifth and sixth switching elements and a connection point of the seventh and eighth switching elements; first to eighth rectifying elements that are respectively connected in parallel to the first to eighth switching elements so that the first to eighth rectifying elements are reversely biased when receiving an input DC voltage; a series circuit of first and second capacitors connected between the first terminals; a series circuit of third and fourth capacitors connected between the second terminals; a first short circuit having a closed state of making electrical conduction between the connection point of the third and fourth switching elements and a connection point of the first and second capacitors and an open state of breaking the electrical conduction between the connection point of the third and fourth switching elements and the connection point of the first and second capacitors; a second short circuit having a closed state of making electrical conduction between the connection point of the seventh and eighth switching elements and a connection point of the third and fourth capacitors and an open state of breaking the electrical conduction between the connection point of the seventh and eighth switching elements and the connection point of the third and fourth capacitors; and a controller configured to perform drive controls of the first to eighth switching elements and open/close controls of the first and second short circuits, the controller being configured:
in the first operation, to switch an operation between a full-wave rectification operation of applying a full-wave rectification voltage, resulting from full-wave rectification of a voltage across the second winding, to the series circuit of the third and fourth capacitors while maintaining the second short circuit in the open state, and a full-wave voltage doubling rectification operation of applying a voltage across the second winding alternately to the third capacitor and the fourth capacitor while maintaining the second short circuit in the closed state, on a basis of magnitude relationship between the first DC voltage received through the first terminals and the second DC voltage output through the second terminals; and
in the second operation, to switch an operation between a full-wave rectification operation of applying a full-wave rectification voltage, resulting from full-wave rectification of a voltage across the first winding, to the series circuit of the first and second capacitors while maintaining the first short circuit in the open state, and a full-wave voltage doubling rectification operation of applying a voltage across the first winding alternately to the first capacitor and the second capacitor while maintaining the first short circuit in the closed state, on a basis of magnitude relationship between the fourth DC voltage output through the first terminals and the third DC voltage received through the second terminals.

2 . The bidirectional DC/DC converter according to claim 1 , wherein the controller is configured, in the first operation, to switch, on a basis of magnitude relationship between the first DC voltage of the first terminals and the second DC voltage of the second terminals, an operation between
a full bridge operation for switching control of: the first and second switching elements so that ON/OFF states of the first and second switching elements are mutually inverted; and the third and fourth switching elements so that ON/OFF states of the third and fourth switching elements are mutually inverted, while maintaining the first short circuit in the open state, and a half bridge operation comprising: setting a duty cycle of the first switching element to equal to or less than 50%; setting a duty cycle of the second switching element to a value same as that of the first switching element; controlling switching of the first and second switching elements so that a phase difference between an ON state of the first switching element and an ON state of the second switching element is 180 degrees; and maintaining the third and fourth switching elements in OFF states, while maintaining the first short circuit in the closed state.

3 . The bidirectional DC/DC converter according to claim 1 , wherein the controller is configured, in the second operation, to switch, on a basis of magnitude relationship between the fourth DC voltage of the first terminals and the third DC voltage of the second terminals, an operation between
a full bridge operation for switching control of: the fifth and sixth switching elements so that ON/OFF states of the fifth and sixth switching elements are mutually inverted; and the seventh and eighth switching elements so that ON/OFF states of the seventh and eighth switching elements are mutually inverted, while maintaining the second short circuit in the open state, and a half bridge operation comprising: setting a duty cycle of the fifth switching element to equal to or less than 50%; setting a duty cycle of the sixth switching element to a value same as that of the fifth switching element; controlling switching of the fifth and sixth switching elements so that a phase difference between an ON state of the fifth switching element and an ON state of the sixth switching element is 180 degrees; and maintaining the seventh and eighth switching elements in OFF states, while maintaining the second short circuit in the closed state.

4 . A bidirectional power converter comprising:
the bidirectional DC/DC converter according to claim 1 configured to perform bidirectional voltage conversion in which the operation is switched between the first operation of outputting the second DC voltage resulting from DC/DC conversion of the first DC voltage received through the first terminals, through the second terminals, and the second operation of outputting the fourth DC voltage resulting from DC/DC conversion of the third DC voltage received through the second terminals, through the first terminals; and a bidirectional inverter configured
to convert the second DC voltage across the second terminals into an AC voltage and output the resultant AC voltage in accordance with the first operation, and
to convert an AC voltage into the third DC voltage to apply the third DC voltage between the second terminals in accordance with the second operation.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Kidera Kazunori
• Yoshizawa Jin

Classifications

• H02M7/487

  Neutral point clamped inverters · CPC title

• H02M3/33546 Primary

  with automatic control of the output voltage or current (H02M3/33561 takes precedence) · CPC title

• H02M7/797 Primary

  using semiconductor devices only · CPC title

• H02M3/33584

  Bidirectional converters · CPC title