JP2012212510A - Battery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery system capable of accurately monitoring a charging rate without carelessly stopping a device which serves as a power supply destination.SOLUTION: A charging state monitoring part of a battery system comprises: a charging state value storage part 74 in which a charging state value of a secondary battery of a main power supply part is stored in a rewritable manner; a first charging state value calculation part 72 which calculates a charging state value of the current main power supply part by integrating detected current values and rewrites a stored charging state value; a driving time measurement part 77 which measures a driving time of the load to be driven; a driving time monitoring part 78 which monitors the measured driving time and outputs a correction start notification when a preset correction start time is reached; a test current value setting part which sets a current value to be changed and discharged to the main power supply part as a test current value based on the correction start notification; and a second charging state value calculation part 73 which acquires a voltage between terminals, calculates the charging state value based on the voltage between the terminals, and rewrites the stored charging state value.

Description

  The present invention relates to a battery system that supplies power to a load using a secondary battery as a power source.

  In recent years, secondary batteries such as lithium ion secondary batteries have attracted attention as energy sources for vehicles such as automobiles, industrial vehicles, and construction machinery. Such a secondary battery is configured when a battery system is configured by a plurality of secondary batteries and a control unit that monitors the secondary batteries, and the charge rate of each secondary battery is monitored by the control unit. Performs charging in a predetermined charging facility.

  Here, various methods have been proposed for detecting the charging rate. As the simplest method, the current value flowing through the secondary battery is detected as needed, the current value is integrated to obtain the charge amount, and the charge amount to the capacity is obtained. However, in this method, since it is obtained by integration, errors occur due to battery temperature, etc., and errors accumulate due to repeated charging and discharging, etc. The error will increase. For this reason, as a method of solving the problem, when the charging rate is between 20% and 80%, the charging rate is estimated by accumulating the current value in the same manner, and when the charging rate exceeds 80% during charging, In addition, when the voltage falls below 20% during discharging, the voltage between terminals is measured as an IV judgment method, and the charging rate is obtained by applying the measured voltage to the relationship between the voltage obtained in advance and the charging rate. A method of performing this has been proposed (see, for example, Patent Document 1).

JP-A-11-121048

  However, according to Patent Document 1, although the charging rate can be appropriately corrected while operating the apparatus using the secondary battery as an energy source, there is a large error during the calculation of the charging rate by integrating the current values. It may occur. Specifically, if the use is repeated such that the detected charging rate fluctuates within a range defined by preset upper and lower limits (20% to 80% in the above example), correction is made. The error will increase without an opportunity. If the error exceeds an allowable value (± 20% in the above example), does the actual charge rate become 100% and an overcharge state occurs before the correction is performed? Alternatively, there is a possibility that the actual charging rate becomes 0% and the device is completely discharged, and the operation of the apparatus must be stopped.

  Further, in Patent Document 1, when correcting the charging rate based on the current value integration, the charging rate is obtained based on the voltage between the terminals in the charged state or in the discharged state. Since the internal impedance changes depending on the magnitude of the value, there is a limit to obtaining an accurate charging rate. In order to determine the charging rate more accurately, an upper limit value and a lower limit value are determined within a range that allows an error in the charging rate obtained by current value integration. A method may be considered in which the operation is stopped, the open-circuit voltage is measured as the voltage between the terminals, and the charging rate is obtained and corrected based on the open-circuit voltage. However, even when the method is applied, if the error exceeds the allowable value defined by the upper limit value and the lower limit value, there is a possibility that the battery may be overcharged or discharged, and the secondary It is necessary to temporarily stop the operation of the device due to the change in the charging rate of the battery, and it has been difficult to apply to a device with a short downtime.

  The present invention has been made in view of the above-described circumstances, and provides a battery system capable of accurately monitoring a charging rate without inadvertently stopping a device as a power supply destination. It is.

In order to solve the above problems, the present invention proposes the following means.
The battery system of the present invention comprises a secondary battery, and supplies a power to a load, a main power supply unit, a main power supply current detection unit that detects a current value charged and discharged to the main power supply unit, and the main power supply unit A main power supply voltage detection unit for detecting a voltage between terminals of the secondary battery, and a current value and a voltage between terminals detected by the main power supply current detection unit and the main power supply voltage detection unit. A charging state monitoring unit that monitors a charging state value representing a charging state of the secondary battery, and the charging state monitoring unit stores the charging state value of the secondary battery of the main power supply unit in a rewritable manner. The current value detected by the main power supply current detection unit is added to the charge state value stored in the charge state value storage unit and the charge state value storage unit, whereby the current value of the main power supply unit is The secondary battery charge state value is calculated and stored in the charge state value storage unit. A first charge state value calculation unit that rewrites the charged state value, a drive time measurement unit that measures a drive time of a load driven by the main power supply unit, and a drive time measured by the drive time measurement unit. A drive time monitoring unit that monitors and outputs a correction start notification when a preset correction start time is reached, and the main power supply unit is charged / discharged based on the correction start notification output by the drive time monitoring unit An inspection current value setting unit that sets a current value to a preset inspection current value, and a battery value that charges and discharges the main power supply unit by the inspection current value setting unit is set to the inspection current value. The inter-terminal voltage detected by the main power supply voltage detection unit is acquired, the charge state value of the secondary battery of the main power supply unit is calculated based on the inter-terminal voltage, and stored in the charge state value storage unit Rewrite the state of charge value It is characterized by having a state of charge value calculating unit.

  According to this configuration, when the drive time measured by the drive time measurement unit reaches the correction start time, the correction start notification is output, and based on this, the inspection current value setting unit is connected to the main power supply unit. The current value charged / discharged is set to a preset inspection current value. The second charge state value calculation unit obtains the inter-terminal voltage detected by the main power supply voltage detection unit while being charged and discharged at the preset inspection current value, and based on this, the charge state Since the value is calculated, the charge state value can be accurately calculated because the internal impedance can be set to a predetermined value without different current values charged / discharged in the secondary battery for each calculation. And also in the first charge state value calculation unit, for the charge state value rewritten in the second charge state value calculation unit, the current value newly detected by the main power supply current detection unit is integrated, Since the charge state value stored in the charge state value storage unit is rewritten, the error can be minimized. In addition, since the rewriting of the charging state value by the second charging state value calculation unit is every correction start time monitored by the driving time monitoring unit, it is periodic, and the time is calculated as the first charging state value calculation. As long as the error that may occur in the calculation of the state of charge by integrating the current value in the unit can be compensated within the allowable range, and the operation of the device having a load with the main power source as the power source is not limited By setting, it is possible to reliably prevent the secondary battery from being overcharged or completely discharged while operating the device appropriately.

  In the battery system, the charging state monitoring unit refers to the charging state value stored in the charging state value storage unit, and the current charging state value indicates that the secondary battery has a charging rate of 100%. A high charge state determination unit that determines whether or not included in a high charge range including a value at the time, the inspection current value setting unit is based on the determination result in the high charge state determination unit, When the state of charge value is included in the high charge range, the test current value is set to a discharge test current value discharged from the main power supply unit.

  According to this configuration, when the high charge state determination unit determines that the current charge state value is included in the high charge range, the inspection current value setting unit sets the discharge inspection current value as the inspection current value. In the state where the main power supply unit is discharged, the second charge state value calculation unit calculates the charge state value. For this reason, in the state where the charge state value is included in the high charge range, even if the actual charge state value is higher than the charge state value stored in the charge state value storage unit, the battery is discharged. However, it is possible to reliably prevent an overcharged state by calculating the state of charge value.

  In the battery system, the charge state monitoring unit refers to the charge state value stored in the charge state value storage unit, and the current charge state value indicates that the secondary battery has a 0% charge rate state. A low charge state determination unit that determines whether or not included in the low charge range including the value at the time, the inspection current value setting unit is based on the determination result in the low charge state determination unit, When the charge state value is included in the low charge range, a charge inspection current value for charging the main power supply unit is set as the inspection current value.

  According to this configuration, when the low charge state determination unit determines that the current charge state value is included in the low charge range, the inspection current value setting unit sets the charge inspection current value as the inspection current value. In the state where the main power supply unit is charged, the second charge state value calculation unit calculates the charge state value. For this reason, even if the actual charge state value is lower than the charge state value stored in the charge state value storage unit in the state where the charge state value is included in the low charge range, the battery is charged. However, it is possible to reliably prevent the battery from being discharged by calculating the state of charge value.

  Further, in the above battery system, a lower limit value of the high charge range is set to be larger than an upper limit value of the low charge range, and a charge state of the secondary battery is set between the high charge range and the low charge range. A medium charging range is set, and the inspection current value setting unit includes the charging state value in the medium charging range based on the determination results of the high charging state determination unit and the low charging state determination unit. Is characterized in that the inspection current value is set to 0A.

  According to this configuration, it is determined by the high charge state determination unit and the low charge state determination unit that the current charge state value is not included in the high charge range and the low charge range, that is, included in the medium charge range. In this case, the inspection current value setting unit sets the inspection current value to 0 A, and the second charging state value calculation unit calculates the charging state value. For this reason, in the state where the charging state value is included in the middle charging range, the actual charging state value should be significantly higher or lower than the charging state value stored in the charging state value storage unit. Can be reliably prevented from being overcharged or completely discharged.

  In the battery system described above, a secondary power source configured by a secondary battery and connected between the main power source unit and the power source for switching connection / disconnection between the main power source unit and the sub power source unit. The charging state monitoring unit has a switch control unit that controls connection / disconnection of the switch between power supplies, the inspection current value setting unit acquires a required current value required by the load, When it is determined by the high charge state determination unit that the state of charge is included in the high charge range, it is determined whether the discharge inspection current value is larger than the required current value, and the required current When it is determined that the discharge inspection current value is larger than the value, the main power supply unit and the sub power supply unit are connected to the switch control unit by the switch between power supplies.

  According to this configuration, when the charge state value is determined to be included in the high charge range by the high charge state determination unit, the second charge state value calculation is performed in a state where the main power supply unit is discharged at the discharge inspection current value. The state of charge is calculated by the unit, but when the inspection current value setting unit determines that the discharge inspection current value is larger than the required current value, the switch control unit uses the inter-power switch to switch the main power unit Connect the sub power supply unit. For this reason, the sub-power supply unit can be charged with power that is excessively discharged with respect to the required current value and is not consumed by the load, and energy efficiency can be improved.

  In the battery system, the battery system further includes a power switch for switching connection between the main power supply unit and the sub power supply unit with respect to the load, and the charge state monitoring unit includes the inspection current value setting unit, When the charge state determination unit determines that the charge state value is not included in the high charge range, the switch control unit is configured to connect the load and the sub power supply unit by the power switch. And

  According to this configuration, when the high charge state determination unit determines that the charge state value is not included in the high charge range, the main power supply unit is not discharged, that is, the power from the main power supply unit to the load. In a state where no supply is performed, the second charge state value calculation unit calculates the charge state value. On the other hand, the switch control unit connects the load and the sub power source unit by the power source switch. For this reason, it is possible to supply power to the load using the secondary power supply unit as a power source while calculating the charge state value of the main power supply unit in the second charge state value calculation unit, and stop the operation of the device including the load. I will not let you.

  Further, in the above battery system, a power source switching for switching a connection between the main power source unit and the sub power source unit for a load, and a sub power source unit connected in parallel with the main power source unit constituted by a secondary battery. The charge state monitoring unit includes a switch control unit that connects the load and the sub power supply unit by the power switch based on the correction start notification output from the drive time monitoring unit. It is characterized by that.

  According to this configuration, based on the correction start notification output from the drive time monitoring unit, the power connection switching control unit connects the load and the sub power supply unit with the power switch, so that the state of the main power unit is achieved. Regardless, while the second charging state value calculation unit calculates the charging state value of the main power supply unit, power can be supplied to the load using the sub power supply unit as a power source, and the operation of the device including the load is stopped. I will not let you.

  In the battery system, the charge state monitoring unit includes a table storage unit in which a voltage / charge state value table indicating a relationship between the inter-terminal voltage and the charge state value is stored, and the second charge state value The calculation unit refers to the voltage / charge state value table from the table storage unit to obtain the charge state value corresponding to the acquired inter-terminal voltage.

  According to this configuration, the second state-of-charge value calculation unit accurately calculates the state-of-charge value by fitting the terminal voltage acquired with reference to the voltage / charge state value table stored in the table storage unit. Can be sought.

  Further, in the above battery system, the table storage unit has a relationship between the voltage between terminals and the charge state value for each of the test current values that can be set by the test current setting unit as the voltage / charge state value table. Is memorized.

  According to this configuration, the charge state value can be obtained more accurately by obtaining the charge state value by fitting the inter-terminal voltage to a different voltage / charge state value table for each inspection current value.

  In the battery system, the table storage unit stores, as the voltage / charge state value table, a relationship between a terminal voltage and a charge state value when a current value flowing through the secondary battery is 0A. And a correction value table in which correction values are indicated for each of the test current values that can be set by the test current setting unit and for each charge state value are stored, and the second charge state value is stored. The calculation unit further obtains a correction value corresponding to the charge state value obtained with reference to the voltage / charge state value table with reference to the correction value table, and charges the charge by the correction value. A value obtained by correcting the state value is output as a current charge state value.

  According to this configuration, after the second charge state value calculation unit obtains the charge state value by fitting the voltage between the terminals acquired with reference to the voltage / charge state value table stored in the table storage unit, With reference to the correction table stored in the table storage unit, the correction value corresponding to the inspection current value and the current charging state value is obtained, and the correction value corresponding to the correction value is used as the charging state value. In addition, the charge state value can be obtained more accurately by eliminating the error due to charging and discharging.

  According to the battery system of the present invention, it is possible to accurately monitor the charging rate without inadvertently stopping the device that is the power supply destination.

It is explanatory drawing explaining the outline | summary of AGV which is an example of the apparatus by which the battery system of embodiment of this invention is mounted. It is a block diagram which shows schematic structure of AGV which is an example of the apparatus by which the battery system of embodiment of this invention is mounted. In AGV which is an example of the apparatus by which the battery system of embodiment of this invention is mounted, it is a circuit diagram explaining the outline | summary of the circuit structure containing a load and a power supply. It is a block diagram which shows the detail of CMU in the battery system of embodiment of this invention. It is a block diagram which shows the detail of BMU in the battery system of embodiment of this invention. In a battery system of an embodiment of the present invention, it is explanatory drawing explaining a voltage and charge state value table memorized by a table storage part. It is a block diagram which shows the detail of a control apparatus in AGV which is an example of the apparatus by which the battery system of embodiment of this invention is mounted. It is a flowchart which shows the monitoring flow of the charging rate by the battery system of embodiment of this invention. It is a flowchart which shows the monitoring flow of the charging rate by the battery system of embodiment of this invention. It is a flowchart which shows the monitoring flow of the charging rate by the battery system of embodiment of this invention. It is a flowchart which shows the monitoring flow of the charging rate by the battery system of embodiment of this invention. It is explanatory drawing at the time of implementing the charge from a main power supply part to a sub-power supply part in the circuit containing the load and power supply of AGV which is an example of the apparatus by which the battery system of embodiment of this invention is mounted. It is explanatory drawing at the time of supplying electric power to a load by a sub power supply part in the circuit containing the load and power supply of AGV which is an example of the apparatus by which the battery system of embodiment of this invention is mounted. It is explanatory drawing explaining the modification of the voltage and charge condition value table memorize | stored in the table memory | storage part in the battery system of embodiment of this invention. It is explanatory drawing explaining the correction value table memorize | stored in the table memory | storage part in the battery system of embodiment of this invention.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an example in which the present invention is applied to an AGV (Automatic Guided Vehicles) 100 as an application example of the battery system including the secondary battery. As shown in FIG. 1, the AGV 100 circulates, for example, stations 111 provided in various places of the circuit 110, receives a transported article at one station 111, and is used as a transport vehicle that delivers the transported goods at another station 111. Has been. In FIG. 1, a contactless power supply facility 112 is provided in part of the circuit 110. Further, the AGV 100 is provided with a power receiving unit 102 (see FIG. 2) corresponding to the power supply facility 112. Specifically, the power supply facility 112 is connected to an external power generation facility such as a power plant, and has a power supply line disposed along the circuit 110. Further, the power receiving unit 102 of the AGV 100 specifically includes an electromagnetic coil disposed along the power supply line while traveling along the circuit 110. For this reason, the AGV 100 receives an alternating current from the electromagnetic coil of the power receiving unit 102 by electromagnetic induction by the alternating current flowing through the power supply line of the power supply facility 112 while traveling on the part of the circuit 110 where the power supply facility 112 is provided. It is possible to do. Thereby, in AGV100 shown in FIG. 1, it is possible to repeat delivery of a conveyed product between the stations 111 while charging the secondary battery of the mounted battery system 1 appropriately by non-contact power feeding.
Note that the battery system described in detail below is applicable not only to the AGV 100 but also to various devices including vehicles such as hybrid vehicles, and in particular, charging opportunities are limited and continuous operation is required. It is effective for AGV100 and the like.

  FIG. 2 shows a block configuration of the AGV 100 including the battery system 1 of this embodiment. FIG. 3 shows a circuit configuration of the AGV 100 including the battery system 1 of this embodiment. As shown in FIGS. 2 and 3, the AGV 100 includes a load 101, a power receiving unit 102 that can receive power from the power supply facility 112, a control device 103 that controls each component including the load 101, and a power receiving unit 102. The battery system 1 includes a battery system 1 that can be charged by receiving power and can supply power to the load 101 by discharging. Examples of the load 101 include an electric motor serving as a travel drive source, a lighting device, and the like.

Further, the battery system 1 includes a main power supply unit 2, a sub power supply unit 3, and a BMS (Battery Management System) 4 that is a battery control unit that controls the main power supply unit 2 and the sub power supply unit 3. The main power supply unit 2 is an assembled battery including a plurality of secondary batteries 2A, 2B, 2C, and 2D. In this embodiment, the main power supply unit 2 is composed of four lithium ion secondary batteries. The sub power supply unit 3 includes a first sub power supply unit 31 and a second sub power supply unit 32. The first sub power supply unit 31 is an assembled battery including a plurality of secondary batteries 31A, 31B, 31C, and 31D. In this embodiment, four lithium ion secondary batteries having a smaller capacity than that of the main power supply unit 2 are used. It consists of a battery. Moreover, the 2nd sub power supply part 32 is comprised with one secondary battery, and is 1 lead acid battery with a capacity | capacitance smaller than the thing of the main power supply part 2 in this embodiment. The main power supply unit 2 serves as a power source of an electric motor mainly serving as a travel drive source, and the first sub power supply unit 31 is used as a backup for the main power supply unit 2. The second sub power supply unit 32 is used as a power source for other incidental equipment, for example, the control device 103.
The configurations and applications of the main power supply unit 2 and the sub power supply unit 3 are examples, and are not limited thereto.

  As shown in FIG. 3, the power receiving unit 102, the load 101, the main power supply unit 2, the first sub power supply unit 31, and the second sub power supply unit 32 are connected in parallel in that order to constitute a circuit. A resistor 4 is provided in parallel between the first sub power supply unit 31 and the second sub power supply unit 32. Further, various switches are provided in the circuit. Specifically, a first switch 51 that switches connection between the load 101 and the power receiving unit 102 with respect to the main power supply unit 2, a second switch 52 that cuts off the connection between the power receiving unit 102 and the load 101, A third switch 53 that cuts off the connection between the power supply unit 2 and the first sub power supply unit 31, and a fourth switch 54 that cuts off the connection between the first sub power supply unit 31, the main power supply unit 2, and the second sub power supply unit 32. And a fifth switch 55 that cuts off the connection between the first sub power supply unit 31 and the second sub power supply unit 32, and a wiring that connects the first sub power supply unit 31 and the load 101 to the positive electrode of the first sub power supply unit 31. A sixth switch 56 and a seventh switch 57 are provided on the side and the negative side, respectively. The first switch 51 to the seventh switch 57 can be driven by the corresponding first switch driving unit 61 to the seventh switch driving unit 67 under the control of the control device 103 to switch the connection.

  The circuit includes an inverter 7 that converts a direct current input from each power source of the main power supply unit 2 and the sub power supply unit 3 into an alternating current and outputs the alternating current to the load 101, and an alternating current input from the power receiving unit 102. Is converted into a direct current and output to each power source of the main power supply unit 2 and the sub power supply unit 3, and a DC-DC converter 9 that sets the voltage of the direct current input to the second sub power supply unit. And are provided. The inverter 7, the AC-DC converter 8, and the DC-DC converter 9 can control the voltage and current value of the output current under the control of the control device 103.

Next, details of the BMS 4 and the control device 103 will be described.
As shown in FIG. 2, the BMS 4 outputs a parameter value signal indicating the state of the secondary battery detected by each of the secondary batteries 2 </ b> A to 2 </ b> D, 31 </ b> A to 31 </ b> D and 32 of the main power supply unit 2 and the sub power supply unit 3. ADC (Analog Digital Converter) 41 (41A to 41D), 42 (42A to 42D), 43 for AD conversion, and CMU (Cell Monitor Unit) 44 (44A) to which digital signals output from the ADCs 41, 42, 43 are input 44D), 45 (45A to 45D), 46, and a plurality of secondary batteries are centrally managed based on signals output from the CMUs 44, 45, 46, and input / output of signals to / from the control device 103 is performed. BMU (Battery Management Unit) 70 to perform.

  As shown in FIG. 4, the main power supply unit 2 is provided with an ammeter 21 as a main power supply unit current detection unit for detecting a current flowing through each as a means for detecting a parameter value. The batteries 2A to 2D include voltmeters 22 and 23 which are main power supply voltage detectors for measuring the voltage between terminals and the can potential, and a thermometer which is a main power supply temperature detector for measuring the can temperature. 24 is provided. The ammeter 21, the voltmeters 22 and 23, and the thermometer 24 are connected to the CMU 44 via the corresponding ADC 41. For this reason, in this embodiment, current, terminal voltage, can potential, and can temperature are detected by the ammeter 21, voltmeters 22, 23, and the thermometer 24 as parameter values representing the state of the secondary battery, The CMU 44 can acquire the parameter value as a digital signal via the ADC 41. The CMU 44 also has a parameter value detection unit 44a that detects a parameter value indicating the state of the battery. When the parameter value detection unit 44a acquires each parameter value via the ADC 41, the parameter value detection unit 44a outputs the battery state information to the BMU 70 in association with the identification ID that uniquely identifies the secondary battery 2A to 2D corresponding to the parameter value. . Similarly, in the secondary power supply unit 3, each secondary battery is provided with means for detecting a parameter value, and the parameter value can be acquired by the CMU via the ADC and output to the BMU 70. Since it is the same structure, description is abbreviate | omitted. Further, in this embodiment, the ADC and the CMU are provided corresponding to each secondary battery. However, the ADC and the CMU may be provided in module units with a plurality of secondary batteries as one module. .

  As shown in FIG. 5, the BMU 70 includes a battery state information reception unit 71 that receives battery state information output from the parameter value detection unit 44 a of the CMU 44, and parameters included in the battery state information received by the battery state information reception unit 71. A first charge state value calculation unit 72 and a second charge state value calculation unit 73 that calculate a charge rate as a charge state value based on the value, a charge state value storage unit 74 in which the calculated charge rate is written, And a table storage unit 75 in which various tables used for calculation by the second charge state value calculation unit 73 are stored. When the first charging state value calculation unit 72 and the second charging state value calculation unit 73 calculate the charging rate, the charging rate stored in the charging state value storage unit 74 is rewritten to the charging rate that is the calculation result. .

  The table storage unit 75 stores a voltage / charge state value table indicating the relationship between the inter-terminal voltage and the charge rate acquired in advance for the secondary batteries 2 </ b> A to 2 </ b> D constituting the main power supply unit 2. . FIG. 6 shows an example of a voltage / charge state value table. As shown in FIG. 6, the voltage / charge state value table T1 shows the relationship between the inter-terminal voltage (open voltage) and the charging rate when no current is supplied to the secondary batteries 2A, 2B, 2C, and 2D. A relation line S2 showing a relation between the voltage between the terminals and the charging rate when the line S1 is discharged from the secondary batteries 2A, 2B, 2C, and 2D with a predetermined discharge inspection current (100A as an example) described later; A relationship line S3 indicating the relationship between the inter-terminal voltage and the charging rate when the secondary batteries 2A, 2B, 2C, and 2D are charged with a predetermined charging inspection current (100A as an example) described later is recorded.

  Further, as shown in FIG. 5, the BMU 70 further extracts a charging rate stored in the charging state value storage unit 74 and outputs it to the control device 103 and a load by the main power supply unit 2. The driving time measuring unit 77 that measures the driving time for driving 101 and the driving time monitoring unit 78 that monitors the driving time measured by the driving time measuring unit 77 are provided. When the drive time reaches a preset correction start time, the drive time monitoring unit 78 outputs a correction start notification to the charge state value output unit 76 and also to the control device 103. In addition, the charge state value output unit 76 periodically extracts the charge rate stored in the charge state value storage unit 74 and outputs the charge rate to the control device 103. When the correction start notification is received separately from this, Also, the charging rate stored in the charging state value storage unit 74 is extracted and output to the control device 103.

  As shown in FIG. 7, the control device 103 is calculated by a load drive control unit 104 that controls driving of the load 101, a first charge state value calculation unit 72, and a second charge state value calculation unit 73 of the BMU 70. A determination unit 105 that receives the charging rate and determines the level of the charging rate, and a current control unit that controls the inverter 7, the AC-DC converter 8, and the DC-DC converter 9 based on the determination result of the determination unit 105. 106, and a switch control unit 107 that controls the first switch driving unit 61 to the seventh switch driving unit 67. The load drive control unit 104 calculates a request current value for driving the load 101 with the request output based on the request output input from the outside, and outputs the request current value to the current control unit 106.

  The determination unit 105 includes a high charge state determination unit 105a that determines whether or not an input charging rate is included in a high charging range including 100%, and an input charging rate included in a low charging range including 0%. A low-charge state determination unit 105b that determines whether or not a high-charge range and a low-charge range, and a threshold storage unit 105c that stores a first threshold value and a second threshold value that define the low-charge range. The determination results of the low charge state determination unit 105b and the high charge state determination unit 105a are output to the current control unit 106 and the second charge state value calculation unit 73 of the BMU 70, respectively.

  The current control unit 106 determines the characteristics of the current output by the inverter 7, the AC-DC converter 8, and the DC-DC converter 9 based on the requested current value from the load drive control unit 104 and the determination result in the determination unit 105. The current value setting unit 106a that outputs a command signal corresponding to the determined current characteristic, and the inspection that stores the inspection current value that is used when the second charging state value calculation unit 73 calculates the charging rate A current value storage unit 106b. In a normal state, the current value setting unit 106 a is configured so that the required current value input from the load drive control unit 104 is discharged from the main power supply unit 2 and supplied to the load 101, and the inverter 7 and the AC-DC converter 8. And the DC-DC converter 9 is driven. The current value setting unit 106a is charged and discharged from the main power supply unit 2 with the inspection current value stored in the inspection current value storage unit 106b as the inspection current value setting unit based on the correction start notification from the BMU 70. Then, the inverter 7, the AC-DC converter 8 and the DC-DC converter 9 are driven.

  In the present embodiment, the inspection current value stored in the inspection current value storage unit 106b includes a discharge current value used during discharging, a charging current value used during charging, and charging / discharging by the main power supply unit 2. A zero current value for designating 0 A used when not implemented is stored. More specifically, the inspection current value is composed of an absolute value representing the current value and a positive / negative sign representing charge / discharge. For example, the discharge current value is +100 A, the charging current value is −100 A, and the zero current value is +0 A. Is set to Then, when the correction start notification is input, the current value setting unit 106a selects one of the inspection current values stored in the inspection current value storage unit 106b based on the determination result by the determination unit 105. Details will be described later.

  Although the configuration of the battery system 1 mounted on the AGV 100 has been described above, the charge state monitoring unit 1A that monitors the charge rate that is the charge state value of the main power supply unit 2 includes the components of the BMU 70 of the BMS 4 and the upper level thereof. The control unit 103 includes a determination unit 105, a current control unit 106, and a switch control unit 107 that constitute a part of the control device 103.

Next, details of the charging rate monitoring procedure performed by the charging state monitoring unit 1A will be described with reference to FIGS.
In a normal time, the load drive control unit 104 outputs a drive command signal to the switch control unit 107, and the switch control unit 107, based on the drive command signal, as shown in FIG. By driving the seventh switch drive unit 67, the first switch 51 is connected to the load 101 side, the second switch 52 is connected, and the third switch 53 to the seventh switch 57 are disconnected. Thereby, the power receiving unit 102 is opened, and only the main power source unit 2 is connected to the load 101. Further, the load drive control unit 104 outputs a requested output to the current value setting unit 106a of the current control unit 106 so that the current value setting unit 106a discharges from the main power supply unit 2 at a current value corresponding to the requested output. A command signal is output to the inverter 7. Thereby, as shown in FIG. 8, the direct current discharged from the main power supply unit 2 is output as a desired alternating current by the inverter 7, and the load 101 can be driven (step S1).

  Then, as the power supply by the main power supply unit 2 is started, measurement of the drive time by the drive time measuring unit 77 is started (step S2). In the main power supply unit 2, various measurements are performed by the ammeter 21, the voltmeters 22 and 23, and the thermometer 24, and battery state information including each parameter value detected by these measurements is output from the CMU 44, and the BMU 70 It is received by the battery state information receiving unit 71. And the 1st charge condition value calculating part 72 of BMU70 extracts a current value regularly from battery condition information, and calculates a charge rate (step S3). That is, the first charge state value calculation unit 72 calculates the charge amount from the previous calculation by multiplying the extracted current value by the corresponding time, and further calculates the charge amount as the target capacity of the secondary battery. Divide by to find the amount of charge rate fluctuation. Then, the first charge state value calculation unit 72 obtains the current charge rate by adding (subtracting) the obtained charge rate fluctuation amount to the charge rate stored in the charge state value storage unit 74. Next, the 1st charge condition value calculating part 72 rewrites the charge rate memorize | stored in the charge condition value memory | storage part 74 to the calculated | required charge rate (step S4). The charging state value output unit 76 periodically reads the charging rate rewritten in the charging state value storage unit 74 and outputs it to the control device 103.

  While the load 101 is being driven, the drive time is monitored by the drive time monitoring unit 78 (step S5). If the driving time does not reach the correction start time (NO), steps S2 and S3 are repeated while the load 101 is driven with the main power source 2 as the power source, and charging and discharging are performed momentarily. The charging rate of the changing main power supply unit 2 is periodically calculated. On the other hand, when the drive time reaches the correction start time (YES), the drive time monitoring unit 78 sends a correction start notification to the charge state value output unit 76 and the current value setting unit of the current control unit 106 in the control device 103. To 106a. The charging state value output unit 76 receives the correction start notification, acquires the current charging rate from the charging state value storage unit 74, and outputs the current charging rate to the determination unit 105 of the control device 103.

  In the determination unit 105, the high charge state determination unit 105a reads the first threshold value from the threshold value storage unit 105c, and the input charging rate is equal to or higher than the first threshold value, that is, high including 100% with the first threshold value as a boundary. It is determined whether it is included in the charge range, and the determination result is output to the current value setting unit 106a and the second charge state value calculation unit 73 of the BMU 70 (step S6). Further, the low charge state determination unit 105b reads the second threshold value from the threshold value storage unit 105c, and the input charging rate is equal to or lower than the second threshold value, that is, within a low charge range including 0% with the second threshold value as a boundary. It is determined whether it is included, and the determination result is output to the current value setting unit 106a and the second charge state value calculation unit 73 of the BMU 70 (step S7).

  When the current value setting unit 106a receives the correction start notification, the current value setting unit 106a refers to the determination results output from the high charge state determination unit 105a and the low charge state determination unit 105b. And when it is a determination result that the state of charge value is included in the high charge range (step S6; YES), as shown in FIG. 9, the current value setting unit 106a checks from the inspection current value storage unit 106b. A discharge current value is acquired as a current value (step S11). Next, the current value setting unit 106a determines whether or not the discharge current value is equal to or less than the required current value corresponding to the required output output from the load drive control unit 104 (step S12). When the discharge current value is equal to or less than the required current value, a command signal is output to the inverter 7 so that the discharge current value is output from the main power supply unit 2, and the inverter 7 is driven (step S13). . As a result, the main power supply unit 2 is discharged at the discharge current value, and the load 101 is driven by the corresponding alternating current.

  In this state, the second charge state value calculation unit 73 performs various measurements with the ammeter 21, voltmeters 22 and 23, and the thermometer 24 in each of the secondary batteries 2 </ b> A to 2 </ b> D, and from the CMU 44 to the BMU 70. The output battery state information is acquired via the battery state information receiving unit 71. The second charge state value calculation unit 73 refers to the voltage / charge state value table stored in the table storage unit 75 and acquires the relation line S2 in the discharge inspection current value based on the determination result from the determination unit 105. The inter-terminal voltage included in the battery state information thus applied is applied to obtain the charging rate (step S14). Then, the second charge state value calculation unit 73 rewrites the charge rate stored in the charge state value storage unit 74 (step S12), proceeds to step S2, and again measures the drive time by the drive time measurement unit 77. And a flow of monitoring this by the drive time monitoring unit 78 is executed.

  In step S12, if the discharge current value is larger than the required current value (NO), the portion corresponding to the difference from the required current value in the current discharged from the main power supply unit 2 is charged to the lead storage battery. To do. That is, first, the current value setting unit 106a outputs a determination result that the discharge current value is larger than the required current value to the switch control unit 107, and the switch control unit 107, based on this, the third switch driving unit 63, By driving the fifth switch drive unit 65, the third switch 53 and the fifth switch 55 are switched from the state shown in FIG. 2 to the connection as shown in FIG. 12 (step S16). Then, the discharge current value is output from the main power supply unit 2, and the required current value in the discharge current value flows to the load 101 and the rest flows to the second sub power supply unit 32 to the inverter 7 and the DC-DC converter 9. A command signal is output to drive the inverter 7 and the DC-DC converter 9 (step S17). Next, the process proceeds to step S11. Similarly, the first charging state value calculation unit 73 calculates the charging rate, and in step S12, the charging rate in the charging state value storage unit 74 is rewritten.

  On the other hand, when it is a determination result that the charge state value is included in the low charge range (step S6; NO, step S7; YES), as shown in FIG. 10, the current value setting unit 106a displays the inspection current value. A charging current value is acquired as an inspection current value from the storage unit 106b (step S21). Furthermore, the current value setting unit 106a outputs a determination result that the charging rate is included in the low charging range to the load drive control unit 104 and the switch control unit 107. As a result, the switch control unit 107 drives the first switch driving unit 61, the second switch driving unit 62, the fourth switch driving unit 64, the sixth switch driving unit 65, and the seventh switch driving unit 67, so that FIG. As shown in FIG. 13, the first switch 51 is connected to the power receiving unit 102 side, the second switch 52 is disconnected, and the fourth switch 54, the sixth switch 55, and the seventh switch 57 are connected. Switching is performed (step S22). As a result, power can be supplied to the load 101 by the first sub power supply unit 31 and the main power supply unit 2 and the power receiving unit 102 are connected.

  Furthermore, the load drive control unit 104 drives the traveling motor included in the load 101 to cause the AGV 100 to travel in the range where the power feeding device 112 is provided in the circuit 110 (step S23). In the power supply facility 112, the main power supply unit 2 is charged via the power receiving unit 102 while traveling using the first sub power supply unit 31 as a power source. At this time, the current value setting unit 106a drives the AC-DC converter 8 based on the acquired charging inspection current value so that the main power source unit 2 is charged with the charging inspection current value (step S24).

  In this state, the second charge state value calculation unit 73 performs various measurements with the ammeter 21, the voltmeters 22 and 23, and the thermometer 24 in each of the secondary batteries 2 </ b> A to 2 </ b> D, and outputs it from the CMU 44 to the BMU 70. The obtained battery state information is acquired via the battery state information receiving unit 71. Then, the second charge state value calculation unit 73 refers to the voltage / charge state value table stored in the table storage unit 75, and sets the relationship line S <b> 3 in the charge inspection current value based on the determination result from the determination unit 105. Then, the charging rate is obtained by fitting the voltage between terminals included in the acquired battery state information (step S25). The second charge state value calculation unit 73 rewrites the charge rate stored in the charge state value storage unit 74 (step S26), proceeds to step S2, and starts measuring the drive time by the drive time measurement unit 77 again. And the flow which monitors this with the drive time monitoring part 78 is performed.

  Further, when the determination result indicates that the charge state value is not included in the high charge range and the low charge range (step S6; NO, step S7; NO), as shown in FIG. 11, the current value setting unit 106a. Acquires the zero current value as the inspection current value from the inspection current value storage unit 106b (step S31). Furthermore, the current value setting unit 106 a outputs a determination result that the charging rate is not included in the high charge range and the low charge range to the switch control unit 107. As a result, the switch control unit 107 drives the first switch driving unit 61, the second switch driving unit 62, the fourth switch driving unit 64, the sixth switch driving unit 66, and the seventh switch driving unit 67, so that FIG. As shown in FIG. 13, the first switch 51 is connected to the charging unit side, the second switch 52 is disconnected, and the fourth switch 54, the sixth switch 56, and the seventh switch 57 are switched to the connected state. (Step 32). As a result, power can be supplied to the load 101 by the first sub power supply unit 31. In addition, the main power supply unit 2 is disconnected from the load 101 and is not in a state where it receives power from the power receiving unit 102. For this reason, no current flows through the main power supply unit 2, and an open circuit voltage can be measured between the positive terminals.

  In this state, the second charge state value calculation unit 73 performs various measurements with the ammeter 21, the voltmeters 22 and 23, and the thermometer 24 in each of the secondary batteries 2 </ b> A to 2 </ b> D, and outputs it from the CMU 44 to the BMU 70. The obtained battery state information is acquired via the battery state information receiving unit 71. Then, the second charge state value calculation unit 73 refers to the voltage / charge state value table stored in the table storage unit 75, and sets the relation line S <b> 1 in the zero test current value based on the determination result from the determination unit 105. Then, the charging rate is obtained by fitting the voltage between terminals included in the obtained battery state information (step S33). The second charge state value calculation unit 73 rewrites the charge rate stored in the charge state value storage unit 74 (step S24), proceeds to step S2, and starts measuring the drive time by the drive time measurement unit 77 again. And the flow which monitors this with the drive time monitoring part 78 is performed.

  As described above, according to the battery system 1 of the present embodiment, when the drive time measured by the drive time measuring unit 77 reaches the correction start time, the drive time monitoring unit 78 outputs a correction start notification. Based on this, the current value setting unit 106a sets the current value charged / discharged to / from the main power supply unit 2 to a preset inspection current value. And the 2nd charge condition value calculating part 73 is the terminal detected with the voltmeter 22 of each secondary battery 2A-2D of the main power supply part 2 in the state charged / discharged with the said test current value set beforehand. Since the inter-current voltage is acquired and the charging rate is calculated based on this, the internal impedance can be set to a predetermined value without different current values charged and discharged to the secondary battery for each calculation. The charge rate can be calculated. And also in the 1st charge condition value calculating part 72, the part for the newly detected electric current value is integrated with respect to the charge rate rewritten in the 2nd charge condition value calculating part 73, and a charge condition value memory | storage part Since the charging rate stored in 74 is rewritten, the error can be minimized. Further, the rewriting of the charging rate by the second charging state value calculating unit 73 is performed every correction start time monitored by the driving time monitoring unit 78, and therefore becomes regular, and the time is set as the first charging state value. Limiting the operation of the AGV 100 having a load 101 that uses the main power supply unit 2 as a power source within a range that can compensate for an error that may occur in the calculation of the charging rate by the current value integration in the calculation unit 72. By setting within a range that does not, it is possible to reliably prevent the secondary battery from being overcharged or discharged completely while the AGV 100 is suitably operated.

  Further, when the high charge state determination unit 105a determines that the current charging rate is included in the high charge range, the inspection current value setting unit 106a sets the discharge inspection current value as the inspection current value and sets the main power supply. The second charging state value calculation unit 73 calculates the charging rate in a state where the unit 2 is discharged. For this reason, even if the actual charging rate is higher than the charging rate stored in the charging state value storage unit 74 in a state where the charging rate is included in the high charging range, charging is performed while discharging. By calculating the rate, it is possible to reliably prevent an overcharged state.

  Further, when the current value setting unit 106 a determines that the discharge inspection current value is larger than the required current value, the switch control unit 107 uses the third switch 53 and the fourth switch 54 to connect the main power supply unit 2 and the sub power supply. The unit 3 is connected. For this reason, the power which is discharged excessively with respect to the required current value and is not consumed by the load 101 can be charged in the sub power supply unit 3, and the energy efficiency can be improved.

  On the other hand, when the high charging state determination unit 105a determines that the charging rate is not included in the high charging range, the main power supply unit 2 is not discharged, that is, the power from the main power supply unit 2 to the load 101 is not discharged. The charging state value is calculated by the second charging state value calculation unit 73 in a state where the supply is not performed. In addition, the switch control unit 107 connects the load 101 and the sub power supply unit 3 by the sixth switch 56. Therefore, power can be supplied to the load 101 using the secondary power supply unit 3 as a power source while calculating the charging rate of the main power supply unit 2 in the second charge state value calculation unit 73, and the operation of the AGV 100 is stopped. I will not let you.

  When the low charging state determination unit 105b determines that the current charging rate is included in the low charging range, the current value setting unit 106a sets the charging inspection current value as the inspection current value and sets the main power supply unit The charging rate is calculated by the second charging state value calculation unit 73 in a state of being charged to 2. For this reason, charging is performed while charging even if the actual charging rate is lower than the charging rate stored in the charging state value storage unit 74 in a state where the charging rate is included in the low charging range. By calculating the rate, it is possible to surely prevent the discharge.

  Furthermore, when it is determined that the current charging rate is not included in the low charging range, that is, included in the middle charging range between the high charging range and the low charging range, the current value setting unit 106a The inspection current value is set to 0 A, and the second charging state value calculation unit 73 calculates the charging rate. For this reason, even if the actual charging rate is significantly higher or lower than the charging rate stored in the charging state value storage unit 74 in a state where the charging rate is included in the middle charging range, it is excessive. It is possible to reliably prevent the battery from being charged or completely discharged.

  In the present embodiment, when the second charging state value calculating unit 73 calculates the charging rate, the acquired inter-terminal voltage is applied with reference to the voltage / charging state value table T1 of the table storage unit 75. By fitting, the charging rate can be obtained accurately. In particular, in the present embodiment, the voltage / charge state value table T1 includes a charge current value, a discharge current value, a zero current value, and a voltage and a charge rate for each inspection current value that can be set by the current value setting unit 106a. The relationship lines S1, S2, and S3 are defined, and charging is performed more accurately without being affected by the internal impedance of the secondary battery by selecting a different relationship line according to the set inspection current value and obtaining the charging rate. The rate can be determined to correct the error.

  In the above embodiment, the high charge state determination unit 105a and the low charge state determination unit 105b determine whether the current charging rate belongs to the high charge range, the low charge range, or the medium charge range. However, it is not limited to this. For example, it is determined only whether it is included in the high charge range, for example, the charge rate is divided into two ranges, that is, a high charge range and a low charge range with one threshold, and if it belongs to the high charge range, The charging rate may be calculated by the second charging state value calculating unit 73, and if the charging rate belongs to the low charging range, the charging rate may be calculated by the second charging state value calculating unit 73 in the charging state. Further, the charging rate may be divided into four or more ranges. In this case, the charge rate is calculated in the charged state in a plurality of ranges with a high charge rate, and the discharge current value is set to a low range in a relatively high range of the charge rate. A high value may be set. Similarly, the discharge current values may be different even in a plurality of ranges where the charging rate is low.

  In the above embodiment, the voltage / charge state value table includes the relationship lines S1 to S3 corresponding to the discharge current value, the charge current value, and the zero current value, respectively, but corresponds to the zero current value. Only the relationship line S1 may be provided. In this case, it is preferable that the table storage unit 75 stores a correction value table that enables correction when charging / discharging is performed using each of the discharge current value and the charge current value. Moreover, in the said embodiment, although the electric current and the voltage between terminals are utilized among the parameter values detected from a secondary battery, can temperature may also be utilized.

14 and 15 show an example in which the correction table is used and the can temperature is also used as a modification of this embodiment.
In the present modification, the table storage unit 75 stores a voltage / charge state value table T2 shown in FIG. 14 and a correction value table T3 shown in FIG. As shown in FIG. 14, the voltage / charge rate cable T2 stores only the relationship line S1 between the terminal voltage and the charge rate at the zero current value. 15A and 15B, the correction value table includes a first correction value table T3 indicating a correction value when the main power supply unit 2 is discharged with a discharge inspection current value, and a charge inspection. This is composed of a second correction value table T4 indicating correction values when the main power supply unit 2 is charged with current values. Both the first correction value table T3 and the second correction value table T4 are configured by a charging rate (SOC) (%) column and a can temperature (° C.) column, and the column corresponding to each charging rate and can temperature. The charging rate correction value is recorded in each.

  Even in such a modification, in steps S14 and S25 (see FIGS. 9 and 10), based on the voltage between terminals when the main power supply unit 2 is charged and discharged with the discharge inspection current value or the charge inspection current value, In the second charge state value determination unit, the charge rate can be obtained in the same manner as in the above embodiment. That is, the second charge state value determination unit applies the acquired inter-terminal voltage to the relationship line S1 of the voltage / charge state value table shown in FIG. 14 to obtain the charge rate. Next, in the case of step S14, with reference to the first correction value table T3, the obtained charging rate and the obtained can temperature are fitted, and the charging rate correction value in the corresponding column is extracted. Then, the charging rate obtained by fitting to the relational expression S1 of the voltage / charging state value table is corrected by the extracted charging rate correction value, and the charging state after storing the corrected charging rate as the true charging rate is stored. The charging rate of the unit 74 is rewritten.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  In the embodiment and the modification, the charging state monitoring unit 1A that monitors the charging rate includes a part of the configuration in the BMU 40 in the BMS 4 that is the battery side control unit, and the other in the control device 103 that is the host. Although it was intended, it is not limited to this. All the configurations may be included on the BMS 4 side, or may be included on the control device 103 side. In the embodiment and the modification, the charging rate is handled as the charging state value. However, instead of the charging rate, the charging amount (product of current amount and time) may be handled as the charging state value.

DESCRIPTION OF SYMBOLS 1 Battery system 1A Charge condition monitoring part 2 Main power supply part 2A, 2B, 2C, 2D Secondary battery 3 Sub power supply part 21 Ammeter (main power supply current detection part)
22 Voltmeter (Main power supply voltage detector)
53 Third switch (switch between power supplies)
54 Fourth switch (switch between power supplies)
55 Fifth switch (switch between power supplies)
56 Sixth switch (power switch)
72 1st charge state value calculating part 73 2nd charge state value calculating part 74 charge state value memory | storage part 75 table memory | storage part 77 drive time measuring part 78 drive time monitoring part 101 load 105a high charge state determination part 105b low charge state Determination unit 106a Current value setting unit (inspection current value setting unit)
107 Switch control unit T1, T2 Voltage / charge state value table T3, T4 Correction value table

Claims (11)

A main power source configured by a secondary battery and supplying power to a load;
A main power supply current detection unit for detecting a current value charged and discharged in the main power supply unit;
A main power supply voltage detection unit for detecting a voltage between terminals of the secondary battery of the main power supply unit;
A charging state monitoring unit that monitors a charging state value representing a charging state of the secondary battery of the main power supply unit based on the current value and the terminal voltage detected by the main power supply current detection unit and the main power supply voltage detection unit. And
The charging state monitoring unit includes a charging state value storage unit in which a charging state value of the secondary battery of the main power supply unit is stored in a rewritable manner;
By accumulating the current value detected by the main power supply current detection unit to the charge state value stored in the charge state value storage unit, the current charge state value of the secondary battery of the main power supply unit is obtained. A first charge state value calculation unit that calculates and rewrites the charge state value stored in the charge state value storage unit;
A drive time measuring unit for measuring a drive time of a load driven by the main power supply unit;
A drive time monitoring unit that monitors the drive time measured by the drive time measuring unit and outputs a correction start notification when a preset correction start time is reached;
An inspection current value setting unit that sets a current value charged / discharged to / from the main power supply unit to a preset inspection current value based on the correction start notification output by the drive time monitoring unit;
In the state where the battery value for charging / discharging the main power supply unit is set to the test current value by the inspection current value setting unit, the inter-terminal voltage detected by the main power supply voltage detection unit is acquired, and the inter-terminal voltage is obtained. And a second charge state value calculating unit for calculating a charge state value of the secondary battery of the main power supply unit and rewriting the charge state value stored in the charge state value storage unit. Battery system. The battery system according to claim 1,
The charge state monitoring unit refers to the charge state value stored in the charge state value storage unit, and the current charge state value includes a value when the secondary battery is in a 100% charge state. A high charge state determination unit that determines whether the charge state value is included in the range, and the test current value setting unit determines that the charge state value is based on the determination result in the high charge state determination unit. In the battery system, the inspection current value is set to a discharge inspection current value discharged from the main power supply unit. The battery system according to claim 2,
The charging state monitoring unit refers to the charging state value stored in the charging state value storage unit, and the current charging state value includes a value when the secondary battery is in a charging rate 0% state, A low charge state determination unit that determines whether the low charge range is relatively lower than the high charge range, and the inspection current value setting unit is based on a determination result in the low charge state determination unit When the charge state value is included in the low charge range, a battery test current value for charging the main power supply unit is set as the test current value. The battery system according to claim 3,
The lower limit value of the high charge range is set to be larger than the upper limit value of the low charge range, and as a charge state of the secondary battery, a middle charge range is set between the high charge range and the low charge range,
When the test current value setting unit is included in the medium charge range based on the determination result of the high charge state determination unit and the low charge state determination unit, the test current value is A battery system set to 0A. The battery system according to claim 1,
The charge state monitoring unit refers to the charge state value stored in the charge state value storage unit, and the current charge state value includes a value when the secondary battery is in a 0% charge state. A low charge state determination unit that determines whether or not the charge state value is included in the range, and the test current value setting unit determines whether the charge state value is in the low charge range based on a determination result in the low charge state determination unit. In the battery system, the test current value is set to a charge test current value for charging the main power supply unit. In the battery system according to any one of claims 2 to 4,
A secondary power source configured by a secondary battery and connected in parallel to the main power source;
A switch between power supplies for switching connection / disconnection between the main power supply unit and the sub power supply unit,
The charge state monitoring unit includes a switch control unit that controls connection / disconnection of a switch between power sources, and the inspection current value setting unit acquires a required current value required by the load, and determines the high charge state The charge state value is determined to be included in the high charge range, the discharge test current value is determined to be greater than the required current value, and the required current value When it is determined that the discharge inspection current value is large, the battery control system connects the main power supply unit and the sub power supply unit to the switch control unit by the switch between power supplies. The battery system according to claim 6,
A power switch for switching the connection between the main power supply unit and the sub power supply unit with respect to the load;
The charge state monitoring unit is configured to switch the power supply to the switch control unit when the inspection current value setting unit determines that the charge state value is not included in the high charge range by the high charge state determination unit. A battery system, wherein the load and the sub power supply unit are connected by a changeover switch. The battery system according to any one of claims 2 to 5,
A sub power source connected in parallel with the main power source constituted by a secondary battery;
A power changeover switch for switching connection between the main power supply unit and the sub power supply unit with respect to a load;
The charge state monitoring unit includes a switch control unit that connects the load and the sub power supply unit by the power supply switch based on the correction start notification output from the drive time monitoring unit. Battery system. The battery system according to any one of claims 1 to 8,
The charging state monitoring unit has a table storage unit in which a voltage / charging state value table indicating a relationship between the terminal voltage and the charging state value is stored,
A battery system, wherein a second charge state value calculation unit obtains the charge state value corresponding to the acquired inter-terminal voltage with reference to the voltage / charge state value table from the table storage unit. The battery system according to claim 9,
The table storage unit stores, as the voltage / charge state value table, a relationship between a terminal voltage and a charge state value for each of the inspection current values that can be set by the inspection current setting unit. Battery system. The battery system according to claim 9,
The table storage unit stores, as the voltage / charge state value table, a relationship between a voltage between terminals and a charge state value when a current value flowing through the secondary battery is 0 A, and the inspection current setting A correction value table in which correction values are stored in association with each of the inspection current values that can be set by the unit and for each state of charge value;
The second charge state value calculation unit further obtains a correction value corresponding to the charge state value obtained with reference to the voltage / charge state value table with reference to the correction value table, A battery system, wherein a value obtained by correcting the charge state value by a correction value is output as a current charge state value.

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