Management device, power storage system

Patent metadata

Field	Value
Publication number	US-11277011-B2
Application number	US-201916961656-A
Country	US
Kind code	B2
Filing date	Feb 8, 2019
Priority date	Mar 13, 2018
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A voltage detector detects a voltage of each cell of a plurality of cells that are series-connected. A plurality of discharge circuits are respectively parallel-connected to the plurality of cells. A controller performs a control to equalize voltages or capacities of the plurality of cells to a target value by controlling discharge time of the plurality of discharge circuits, based on the voltages of the plurality of cells detected by the voltage detector. The controller sets the target value higher as an amount of change in the voltages of the plurality of cells in a predetermined period is larger.

First claim

The invention claimed is:

1. A management device comprising:
a voltage detector that detects a voltage of each cell of a plurality of cells that are series-connected;
a plurality of discharge circuits respectively parallel-connected to the plurality of cells; and
a controller that performs a control to equalize voltages or capacities of the plurality of cells to a target value by controlling discharge time of the plurality of discharge circuits, based on the voltages of the plurality of cells detected by the voltage detector,
wherein the controller sets the target value higher as an amount of change in the voltages of the plurality of cells in a predetermined period is larger, and the target value is common to the plurality of cells.

2. The management device according to claim 1 wherein, when the amount of change is zero, the controller sets a voltage of a cell having a lowest voltage of the voltages of the plurality of cells as the target value.

3. The management device according to claim 1 , wherein, when the amount of change is zero, the controller sets a rechargeable capacity of a cell having a largest rechargeable capacity of rechargeable capacities of the plurality of cells as the target value.

4. The management device according to claim 1 , wherein in an idle period of the plurality of cells, the controller causes the voltage detector to regularly detect the voltages of the plurality of cells, calculates an amount of change between voltages of the plurality of cells detected last time and voltages of the plurality of cells detected this time, and performs an equalization process between the plurality of cells, based on a target value depending on the amount of change.

5. A power storage system comprising:
the plurality of cells that are series-connected; and
the management device according to claim 1 that manages the plurality of cells.

6. The power storage system according to claim 5 , wherein:
the power storage system is mounted on a vehicle, and
during parking of the vehicle, the management device regularly starts up to cause the voltage detector to detect the voltages of the plurality of cells.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Nagase Ryosuke
• Nishikawa Shinya
• Iida Takashi

Classifications

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• H02J7/54 Primary

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• H01M10/48

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title