Secondary battery system with plural batteries and method of distributing charge/discharge power, etc.

Patent metadata

Field	Value
Publication number	US-2016013670-A1
Application number	US-201414773144-A
Country	US
Kind code	A1
Filing date	Mar 3, 2014
Priority date	Mar 4, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

A secondary battery system including plural batteries, extends the lifetime of each battery, and improves the charge/discharge (energy) efficiency of a whole system is provided. A secondary battery system includes plural batteries individually controllable for charging/discharging, plural PCSs each connected to the corresponding battery and performing charging/discharging to the connected battery, and a battery controller distributing a charge/discharge power value as a whole system to each of the PCSs at a fixed cycle or an arbitrary timing. The battery controller includes a preference order calculator setting a preference order to the plural batteries at each time point based on a deterioration characteristic of each battery related to each SOC thereof, and a distribution rate determining unit distributing the charge/discharge power value to the PCSs in accordance with the preference order.

First claim

1 . A secondary battery system comprising:
a plurality of batteries individually controllable for charging/discharging; a plurality of charging/discharging devices each connected with the corresponding battery, and performing charging/discharging to the connected battery; and a battery controller distributing, to each of the charging/discharging devices, a charge/discharge power value or a current value as a whole system at a fixed cycle or at an arbitrary timing, the battery controller comprising: a preference order calculator setting a preference order to the plurality of batteries at each time point based on a deterioration characteristic of each battery related to an SOC thereof; and a distribution rate determiner distributing the charge/discharge power value or the current value to the charging/discharging devices in accordance with the preference order.

2 . The secondary battery system including the plurality of batteries according to claim 1 , wherein the battery controller further comprises a charge-necessity-value calculator calculating a charge necessity value based on a charge necessity characteristic, the charge necessity characteristic being on a basis of a deterioration speed of the battery relative to the SOC thereof at the time point, and the deterioration speed being the deterioration characteristic of each battery.

3 . A method of distributing charge/discharge power, etc., comprises:
a plurality of batteries individually controllable for charging/discharging; a plurality of charging/discharging devices each connected with the corresponding battery, and performing charging/discharging to the connected battery; and a battery controller distributing, to each of the charging/discharging devices, a charge/discharge power value or a current value as a whole system at a fixed cycle or at an arbitrary timing, wherein the battery controller sets a preference order to the plurality of batteries at each time point based on a deterioration characteristic of each battery related to an SOC thereof, and to distribute the charge/discharge power value or the current value to the charging/discharging devices in accordance with the preference order.

4 . The charge/discharge power, etc., distribution method according to claim 3 wherein a charge necessity characteristic based on a deterioration speed of the battery relative to the SOC thereof at the time point is applied as the deterioration characteristic of each battery.

5 . The charge/discharge power, etc., distribution method according to claim 3 , wherein a charge necessity characteristic based on a deterioration speed relative to the SOC of each battery and a temperature thereof at the time point is applied as the deterioration characteristic of each battery.

6 . The charge/discharge power, etc., distribution method according to claim 4 , wherein a characteristic value proportional to a derivative value of a deterioration speed characteristic of the battery relative to the SOC thereof is applied as the charge necessity characteristic of each battery.

7 . The charge/discharge power, etc., distribution method according to claim 3 , wherein in the distribution of the charge/discharge power value to the respective charging/discharging devices in accordance with the preference order, the charge/discharge power value is distributed to the respective charging/discharging devices based on an efficiency characteristic to charge/discharge power of the battery and the charging/discharging device.

8 . The charge/discharge power, etc., distribution method according to claim 7 , wherein in the distribution of the charge/discharge power value to the respective charging/discharging devices in accordance with the preference order, when a total value of maximum chargeable/dischargeable power values (MPP) of all batteries is equal to or smaller than a charge/discharge instruction value of a whole system at the time point, the respective maximum chargeable/dischargeable power values (MPP) are distributed to all batteries.

9 . The charge/discharge power, etc., distribution method according to claim 7 , wherein in the distribution of the charge/discharge power value to the respective charging/discharging devices in accordance with the preference order, when a charge/discharge instruction value of a whole system at the time point is smaller than a total value of maximum chargeable/dischargeable power values (MPP) of all batteries, and is equal to or larger than a total value of maximum efficiency point power values (MEP) of all batteries, the respective MEPs are once distributed to all chargeable/dischargeable batteries, and a remaining not distributed yet is additionally distributed to each battery having already undergone the distribution at a rate of remaining amount (MPP−MEP).

10 . The charge/discharge power, etc., distribution method according to claim 7 , wherein in the distribution of the charge/discharge power value to the respective charging/discharging devices in accordance with the preference order, when a charge/discharge instruction value of a whole system at the time point is smaller than a total value of maximum efficiency point power values (MEP) of all batteries, the distribution is performed to the chargeable/dischargeable batteries in an order of the higher preference at a rate of MEP, the number of the chargeable/dischargeable batteries making a ratio between distributed power and the MEP closest to 1,

11 . The charge/discharge power, etc., distribution method according to claim 3 , wherein, as a result of the charge/discharge power distribution, the battery that has zero distribution amount is transitioned to a power saving mode that has a smaller power consumption than at a time of performing charging/discharging.

12 . The charge/discharge power, etc., distribution method according to claim 5 , wherein a characteristic value proportional to a derivative value of a deterioration speed characteristic of the battery relative to the SOC thereof is applied as the charge necessity characteristic of each battery.

13 . The charge/discharge power, etc., distribution method according to claim 8 , wherein in the distribution of the charge/discharge power value to the respective charging/discharging devices in accordance with the preference order, when a charge/discharge instruction value of a whole system at the time point is smaller than a total value of maximum chargeable/dischargeable power values (MPP) of all batteries, and is equal to or larger than a total value of maximum efficiency point power values (MEP) of all batteries, the respective MEPs are once distributed to all chargeable/dischargeable batteries, and a remaining not distributed yet is additionally distributed to each battery having already undergone the distribution at a rate of remaining amount (MPP−MEP).

Assignees

• Toshiba Kk

Inventors

• Tohara Masahiro
• Sameda Yoshito
• Mizutani Mami
• Endo Tamotsu

Classifications

• H02J4/25

  for transfer of electric power between AC and DC networks, e.g. for supplying the DC section within a load from an AC mains system · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/56

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