Battery control device

Abstract

A battery control device which obtains a state of charge of a secondary battery from characteristics representing a relationship of a state of charge and a voltage of the secondary battery comprises a calling unit which calls a first characteristic among a plurality of the characteristics stored in advance based on use history information of the secondary battery, a correction limit width designation unit which designates a correction limit width for prescribing a tolerance level of correcting the first characteristic, and a direct detection correction unit which creates a second characteristic in which the first characteristic has been corrected according to the correction limit width based on a current value and a voltage value of the secondary battery, wherein the state of charge of the secondary battery is obtained using the second characteristic.

1 . A battery control device which obtains a state of charge of a secondary battery from characteristics representing a relationship of a state of charge and a voltage of the secondary battery, comprising:
 a calling unit which calls a first characteristic among a plurality of the characteristics stored in advance based on use history information of the secondary battery;   a correction limit width designation unit which designates a correction limit width for prescribing a tolerance level of correcting the first characteristic; and   a direct detection correction unit which creates a second characteristic in which the first characteristic has been corrected according to the correction limit width based on a current value and a voltage value of the secondary battery,   wherein the state of charge of the secondary battery is obtained using the second characteristic.   
     
     
         2 . The battery control device according to  claim 1 ,
 wherein the calling unit calls the first characteristic by using at least one among a state of health, a current history, a temperature history and a state of charge history of the secondary battery as the use history information.   
     
     
         3 . The battery control device according to  claim 1 ,
 wherein the correction limit width designation unit designates, as the correction limit width, a certain voltage width for each state of charge or a certain state of charge width for each voltage.   
     
     
         4 . The battery control device according to  claim 1 ,
 wherein the correction limit width designation unit designates, as the correction limit width, a voltage width which differs for each predetermined state of charge or a state of charge width which differs for each predetermined voltage.   
     
     
         5 . The battery control device according to  claim 1 ,
 wherein the correction limit width designation unit changes the correction limit width according to an operating history of the secondary battery.   
     
     
         6 . The battery control device according to  claim 5 ,
 wherein the correction limit width designation unit changes the correction limit width according to the operating history of the secondary battery by selecting one correction limit width among a plurality of the correction limit widths stored in advance based on the first characteristic.   
     
     
         7 . The battery control device according to  claim 1 , further comprising:
 a voltage operation unit which calculates an open voltage value and a polarization voltage value of the secondary battery based on a current value and a voltage value of the secondary battery,   wherein the direct detection correction unit acquires, a plurality of times within a predetermined time range, an open voltage value of the secondary battery when the current value and the polarization voltage value are respectively smaller than a predetermined threshold, and creates the second characteristic by using each of the acquired open voltage values, a current integrated value in an acquisition period of each of the open voltage values, and the first characteristic.   
     
     
         8 . The battery control device according to  claim 1 ,
 wherein:   the correction limit width designation unit designates a second correction limit width for prescribing a tolerance level of correcting the second characteristic created in a past by the direct detection correction unit; and   the direct detection correction unit creates the second characteristic by using the correction limit width designated by the correction limit width designation unit for a present first characteristic and the second correction limit width designated by the correction limit width designation unit for a past second characteristic.   
     
     
         9 . The battery control device according to  claim 1 ,
 wherein the direct detection correction unit corrects the first characteristic based on a current value and a voltage value of the secondary battery, and limits the first characteristic after correction to be within a range of the correction limit width.   
     
     
         10 . The battery control device according to  claim 9 ,
 wherein the direct detection correction unit updates the use history information based on the first characteristic after correction including parts outside the range of the correction limit width.   
     
     
         11 . The battery control device according to  claim 10 ,
 wherein the direct detection correction unit determines whether the first characteristic after correction is within the range of the correction limit width, and updates the use history information when the first characteristic after correction determined to be outside the range of the correction limit width satisfies a predetermined convergence condition.   
     
     
         12 . The battery control device according to  claim 11 ,
 wherein the convergence condition includes at least one of either a first condition in which a number of times that the first characteristic after correction was continuously determined to be outside the range of the correction limit width is equal to or greater than a predetermined number of times, or a second condition in which a variance in the first characteristic after correction is equal to or less than a predetermined threshold.