Voltage balance correction circuit

Patent metadata

Field	Value
Publication number	US-11095128-B2
Application number	US-201715717860-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	Mar 30, 2015
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

A voltage balance correction circuit includes multiple voltage correction circuits that correspond one-to-one to multiple electricity storage cells connected in series, and a control circuit that is configured to control the multiple voltage correction circuits based on voltages of the multiple electricity storage cells. The multiple voltage correction circuits include first coils that are connected to the electricity storage cells in parallel, respectively, field-effect transistors that are configured to turns on/off connections of the first coils with the electricity storage cells, respectively, under control of the control circuit, and second coils that are magnetically respectively coupled with the first coils. In the multiple voltage correction circuits, the second coils are connected in parallel.

First claim

The invention claimed is:

1. A voltage balance correction circuit comprising:
multiple voltage correction circuits corresponding one-to-one to multiple electricity storage cells connected to one another in series; and
a control circuit configured to control the multiple voltage correction circuits based on voltages of the respective electricity storage cells, wherein:
the multiple voltage correction circuits each comprise a first coil connected to a corresponding electricity storage cell in parallel, a switch configured to turn ON/OFF connection of the first coil with the corresponding electricity storage cell under control of the control circuit, and a second coil magnetically coupled with the first coil, the switch configured to turn ON/OFF with a voltage that is lower than a rated voltage of the corresponding electricity storage cell,
through the multiple voltage correction circuits, the second coils of the respective voltage correction circuits are connected to one another in parallel,
each of the multiple voltage correction circuits comprises a switch driver circuit configured to operate on electric power of a corresponding electricity storage cell to turn ON/OFF the switch, and
the control circuit configured to control the switch driver circuit such that the switch driver circuit alternates turning ON/OFF of the switch of a selected one of the multiple voltage correction circuits corresponding to an electricity storage cell having a highest voltage of the multiple electricity storage cells, and meanwhile keeps the switches of remaining ones of the multiple voltage correction circuits, corresponding to remaining ones of the electricity storage cells, in a rectified state.

2. The voltage balance correction circuit according to claim 1 , wherein the control circuit selects an electricity storage cell corresponding to the voltage correction circuit of which a switch is to be kept in a rectified state, in accordance with voltages of the electricity storage cells.

3. The voltage balance correction circuit according to claim 1 , wherein the voltage correction circuits are each an isolated forward converter circuit or an isolated flyback converter circuit constituted by the first coil as a primary winding and the second coil as a secondary winding.

Assignees

• Fdk Corp

Inventors

• Miyazaki Masatsuru
• Fukui Norio

Classifications

• H02J7/56 Primary

  Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters · CPC title

• H02M3/33507

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

• H01M10/441

  for several batteries or cells simultaneously or sequentially · CPC title

• H01M2010/4271

  Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing · CPC title

• H02M3/33546

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