JP2022069374A - Battery management device and battery device - Google Patents

Abstract

To provide a battery management device capable of improving the accuracy of voltage measurement, and a battery device.SOLUTION: A battery management device 100 comprises a micro computer 1 and a monitoring IC 3. The micro computer includes a function for adjusting and setting a voltage measurement range for a plurality of battery cells 7. The monitoring IC measures a voltage of each battery cell in the voltage measurement range set by the micro computer. The battery management device can improve the accuracy of voltage measurement because an appropriate voltage measurement range can be adjusted by the micro computer.SELECTED DRAWING: Figure 1

Description

The disclosure in this specification relates to a battery management device and a battery device.

Patent Document 1 discloses a battery device that executes equalization processing for each battery block in order to rapidly reduce voltage variations for a plurality of batteries.

Japanese Unexamined Patent Publication No. 2010-141957

In the device for managing the state of the battery, it is important to perform the equalization of the battery, the estimation of the storage rate (SOC) of the battery, the estimation of the degree of deterioration of the battery (SOH), and the like with high accuracy. For this purpose, it is required to improve the measurement accuracy of the battery voltage.

One of the purposes disclosed in this specification is to provide a battery management device and a battery device capable of improving the accuracy of voltage measurement.

The plurality of embodiments disclosed herein employ different technical means to achieve their respective objectives. Further, the scope of claims and the reference numerals in parentheses described in this section are examples showing the correspondence with the specific means described in the embodiment described later as one embodiment, and limit the technical scope. is not.

One of the battery management devices to be disclosed is a range setting unit (1) that sets a limited measurement range that limits the voltage measurement range for a plurality of in-vehicle batteries (7), and a limited measurement range set by the range setting unit. A measuring unit (3; 103) for measuring the voltage of the battery is provided.

One of the disclosed battery devices is a plurality of in-vehicle batteries (7), a range setting unit (1) that sets a limited measurement range that limits the voltage measurement range of the battery, and a limitation set by the range setting unit. It is provided with a measuring unit (3; 103) for measuring the voltage of the battery in the measuring range.

According to this technique, the range setting unit (1) can set a limited voltage measurement range of the entire voltage range of the battery (7). Since an appropriate voltage measurement range can be set, the accuracy of voltage measurement can be improved.

It is a block diagram which concerns on the battery device. It is a block diagram of a monitoring IC. It is a characteristic diagram which shows the relationship between OCV and SOC about a battery cell. It is a flowchart which showed the battery management of 1st Embodiment. It is a flowchart which showed the battery management of 2nd Embodiment. It is a characteristic diagram explaining the operation which concerns on SOH estimation. It is a flowchart which showed the battery management of 3rd Embodiment. It is a flowchart which showed the battery management of 4th Embodiment. It is a block diagram of the monitoring IC which concerns on 5th Embodiment. It is a timing chart for explaining voltage detection. It is a timing chart for explaining voltage detection. It is a flowchart for demonstrating acquisition target setting process.

Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each form, the same reference numerals may be given to the parts corresponding to the matters described in the preceding forms, and duplicate explanations may be omitted. When only a part of the configuration is described in each form, other forms described above can be applied to the other parts of the configuration. Not only the combinations of the parts that clearly indicate that they can be combined in each embodiment, but also the parts of the embodiments that are not explicitly combined if there is no problem in the combination. It is also possible.

<First Embodiment>
The first embodiment will be described with reference to FIGS. 1 to 4. A battery management device capable of achieving the object specified in the specification can be applied to the management of a secondary battery mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle. Vehicles include passenger cars, buses, construction work vehicles, agricultural machinery vehicles and the like. As the secondary battery, a lithium ion secondary battery, a nickel hydrogen secondary battery, an organic radical battery and the like can be used.

FIG. 1 shows a configuration related to the battery device 200 and an external device for charging the assembled battery 5. The battery device 200 includes an assembled battery 5 and a battery management device 100.

The battery management device 100 includes a control device 10 related to the assembled battery 5. The external device includes a charging facility (CF) 12 and a charging terminal (CT) 11. Electric power can be exchanged between the assembled battery 5 and the charging terminal 11 by the charge / discharge circuit (CDC) 8 mounted on the vehicle.

The battery management device 100 is provided in the vehicle described above. The battery management device 100 functions as a management device for monitoring and controlling charging / discharging of the assembled battery 5 including the secondary battery in the vehicle described above. The assembled battery 5 can be charged by an external device.

A power process is provided between the battery management device 100 and the charging equipment 12 to allow power to flow in one direction or in both directions. The charging facility 12 is a power supply device arranged in a house, a business establishment, or the like. The charging equipment 12 is configured as a simple power outlet or a charging stand for charging.

The charging terminal 11 is a portable or stationary device. The charging terminal 11 can be arranged in the charging equipment 12 or the vehicle. The charging terminal 11 communicates with the vehicle using a dedicated signal line. The charging terminal 11 can also be configured as a charger. The system main relay 6 can switch the charging terminal 11 and the assembled battery 5 between an energized state and a non-energized state.

The charging equipment 12 includes an AC power source and an outlet that outputs electric power supplied from the AC power source. AC power is supplied from a small power generation facility or a wide area power grid. The outlet is located outside the facility that provides the charging facility 12 and is capable of accepting a predetermined plug. The outlet and the plug provide a connection device for connecting between the charging equipment 12 and the charging terminal 11.

The vehicle equipped with the battery management device 100 has an inlet. The inlet provides an input-side connector for the charging terminal 11. The inlet has a terminal group including a plurality of terminals for DC power and a plurality of terminals for data communication.

The charging terminal 11 includes a plug that can be connected to the outlet of the charging equipment 12. The plug can be energized with AC power. The charging terminal 11 includes a connector that can be connected to the inlet of the vehicle. The connector is also called a charging gun. The connector has a terminal group including a plurality of terminals for AC power and a plurality of terminals for data communication. The vehicle inlet and the connector of the charging terminal 11 provide a connection device for connecting the charging terminal 11 and the vehicle. The charging terminal 11 includes a control device that adjusts the power supplied to the plug of the charging terminal 11 and supplies it to the connector. The control device of the charging terminal 11 includes a switch circuit for interrupting the power supply to the connector. The control device of the charging terminal 11 can include a voltage conversion circuit.

The control device of the charging terminal 11 is also a communication device for communicating with the vehicle via the connector of the charging terminal 11. The control device of the charging terminal 11 cooperates with the control device 10 of the battery management device 100 to execute a charging process for controlling charging of the assembled battery 5. The control device of the charging terminal 11 transmits a signal indicating that power can be supplied from the charging terminal 11 by a CPLT signal. Further, the control device of the charging terminal 11 receives a signal indicating that the assembled battery 5 can be discharged by the CPLT signal. The control device of the charging terminal 11 interrupts the power supply from the charging terminal 11 to the assembled battery 5.

The assembled battery 5 supplies power to a traveling electric motor provided in the vehicle. The assembled battery 5 has a high capacity and a high voltage so that it can be used as a power source for traveling the vehicle. The assembled battery 5 includes a plurality of battery groups connected in series or in parallel. The battery group includes a plurality of battery cells 7 connected in series. The battery cell 7 is a secondary battery.

The charge / discharge circuit 8 is mounted on the vehicle. The charge / discharge circuit 8 functions as a charging circuit that rectifies and transforms the electric power supplied to the inlet of the vehicle and supplies it to the assembled battery 5. The charge / discharge circuit 8 can also function as a discharge circuit that converts the DC power obtained from the assembled battery 5 into AC power and outputs the DC power to the inlet of the vehicle. The charging / discharging circuit 8 enables charging of the assembled battery 5 from the AC power supply of the charging equipment 12 and reverse power flow from the assembled battery 5 to the AC power supply. The charge / discharge circuit 8 can include an inverter circuit and a voltage converter circuit. The control device 10 of the battery management device 100 controls the charge / discharge circuit 8.

The control device 10 includes a monitoring IC (BMIC) 3, an insulating element (IE) 2, and a microcomputer (μC) 1. The monitoring IC 3 functions as a measuring unit for measuring the voltage (voltage between terminals) between the anode and the negative electrode of each battery cell 7. One monitoring IC 3 measures, for example, the voltage between terminals of each battery cell 7 included in one battery group.

The microcomputer 1 and each monitoring IC 3 are insulated by an insulating element 2. The microcomputer 1 acquires the voltage between terminals measured by each monitoring IC 3 via the insulating element 2. The microcomputer 1 monitors each battery cell 7 through each monitoring IC 3 and manages the state of the assembled battery 5 such as the charge / discharge state. The monitoring IC 3 and the monitoring IC 3 are insulated by an insulating element (IE) 21. The reason why this insulation configuration is provided is that the GND level is different for each monitoring IC3, and the communication performance is ensured.

The microcomputer 1 adjusts the voltage measurement range in the battery cell 7 to set a limited measurement range. The microcomputer 1 sets a limited measurement range when the vehicle is in a state where the influence of noise is small. The microcomputer 1 functions as a range setting unit capable of setting an arbitrary limited measurement range among the voltages in the entire range of the battery cell 7. The microcomputer 1 sets the voltage measurement range adjusted by the command transmitted to the monitoring IC 3 as the limited measurement range. The monitoring IC 3 interprets the command output from the microcomputer 1 and operates within the voltage measurement range included in this command.

As an example, the microcomputer 1 sets a limited measurement range with the following logic. The microcomputer 1 sets a limited measurement range including the maximum value by using the maximum value among the voltage measurement values measured by the monitoring IC 3 for the voltage in the entire range in the battery cell 7. The microcomputer 1 sets a limited measurement range including the minimum value by using the minimum value among the voltage measurement values measured by the monitoring IC 3 for the voltage in the entire range in the battery cell 7. The microcomputer 1 sets a limited measurement range by using the maximum value and the minimum value among the voltage measurement values measured by the monitoring IC 3 for the voltage in the entire range of the battery.

As shown in FIG. 2, for example, the monitoring IC 3 includes a command unit (CS) 31, an analog-to-digital converter (A / D) 32, a level shifter (L / S) 33, and a switch group (MUX) 34. The monitoring IC 3 further includes an equalization circuit (BC) 4.

The command unit 31 includes a serial I / O, a non-volatile memory, and a digital filter, and has a function of interpreting a command from the microcomputer 1.

The analog-to-digital converter 32 includes an A / D converter that forms an electronic circuit that converts an analog electric signal into a digital electric signal, and a clamp circuit for limiting the input range of the A / D converter. The number of quantization bits of the A / D converter is a fixed value. By controlling the clamp circuit by the command unit 31, the input range of the A / D converter is controlled.

The switch group 34 has a function of arbitrarily selecting the voltage of each battery cell 7. The switch group 34 has a function of selecting a plurality of inputs and outputting them as one signal.

The level shifter 33 functions as a level shifter and a gain sector. The level shifter 33 includes an operational amplifier and a plurality of feedback circuits connected in parallel between the input terminal and the output terminal of the operational amplifier. This feedback circuit contains a switch and a capacitor connected in series. The capacitances of the capacitors included in the plurality of feedback circuits may be the same or different.

The switches of the plurality of feedback circuits included in the level shifter 33 are selectively controlled to the energized state and the cutoff state. This changes the number of capacitors connected between the input terminal and the output terminal of the operational amplifier. The capacitance between the input terminal and the output terminal of the operational amplifier changes. In addition, the resistance between the input terminal and the output terminal of the operational amplifier changes. As a result, the gain and offset of the level shifter 33 are controlled.

By limiting the input range of the analog-digital converter 32 and adjusting the gain and offset of the level shifter 33, the voltage range of the analog electric signal to be analog-digitally converted by the analog-to-digital converter 32 is controlled. The voltage range of the voltage of the battery cell 7 to be analog-digitally converted by the analog-digital converter 32 is controlled. As a result, the voltage measurement range is adjusted.

The monitoring IC 3 measures the voltage of the battery cell 7 in the voltage measurement range set by the microcomputer 1. The monitoring IC 3 functions as a measuring unit that measures the voltage of the battery cell 7 in the limited measurement range set by the microcomputer 1.

The battery cell 7 included in the assembled battery 5 has a unique characteristic regarding the relationship between the storage rate (SOC) and the open circuit voltage (OCV). In this specification, the storage rate of the battery cell 7 may be described as SOC. When the battery cell 7 is a lithium ion secondary battery, the battery cell 7 has characteristic data as shown in FIG. 3 as an example. The characteristic data as shown in FIG. 3 is stored in the storage unit (ME) 22 of the control device 10. The temperature dependence of the SOC and OCV characteristic data of various secondary batteries is stored in the storage unit 22. The characteristic data corresponding to the type and temperature of the battery cell 7 is read out by the microcomputer 1. The storage unit 22 may be built in the microcomputer 1. In the drawings, the microcomputer 1 and the storage unit 22 are shown separately in order to clearly indicate the components.

The microcomputer 1 functions as an SOC estimation unit that estimates the SOC of the battery cell 7 by an operation using the voltage between terminals of the battery cell 7 measured by the monitoring IC 3 and this characteristic data. The microcomputer 1 functions as an SOC estimation unit that estimates SOC based on voltage measurement values measured in the entire voltage range of the measurable battery cell 7. The microcomputer 1 functions as an SOC estimation unit that estimates SOC based on the measured voltage measurement value.

The characteristic data shown in FIG. 3 show the relationship between the SOC of the battery cell 7 and the open circuit voltage. This characteristic data includes a low change region in which the voltage change width with respect to the SOC is equal to or less than a predetermined value. The characteristic data includes a high change region in which the voltage change is larger than the low change region in each of the SOC range lower than the low change region and the SOC range higher than the low change region.

The low voltage change region is the range indicated by the arrow on the vertical axis of FIG. The SOC of the battery cell 7 corresponding to the low change region corresponds to the range indicated by the arrow on the horizontal axis of FIG. The entire range of the voltage between the terminals of the battery cell 7 includes a low change region in which the voltage change width with respect to the SOC is smaller than that in the low SOC region and the high SOC region.

The microcomputer 1 functions as a range setting unit for setting a limited measurement range based on the inherent characteristics of the battery cell 7 showing the relationship between the SOC and the open circuit voltage. It is preferable that the microcomputer 1 sets the voltage range included in the low change region as the limited measurement range among the voltages in the entire range related to the battery cell 7. The control device 10 has a function capable of performing high-precision voltage measurement and accurate estimation of the storage state of the battery cell 7 having such characteristics.

The equalization circuit 4 functions as an equalization processing unit that executes a process (equalization process) for reducing voltage variations of a plurality of battery cells 7 included in the battery group. The equalization circuit 4 includes a control unit and an equalization circuit unit. The control unit is built in the monitoring IC 3. The equalization circuit unit is connected to each battery cell 7. The equalization circuit unit is built in the monitoring IC3. The equalization circuit unit may be arranged outside the monitoring IC 3.

In the equalization process, for example, among the plurality of battery cells 7 included in the battery group, the battery cell 7 showing a relatively high voltage measurement value is discharged. At the same time, among the battery cells 7 included in the battery group, the battery cell 7 showing a relatively low voltage measurement value is charged. As a result, the SOCs of the plurality of battery cells 7 included in the battery group are equalized.

When the equalization processing condition is satisfied, the microcomputer 1 sends a signal to the equalization circuit 4 to instruct the corresponding battery group to perform the equalization processing. The microcomputer 1 does not send a signal instructing the equalization processing to the equalization circuit 4 when the equalization processing condition is not satisfied. The microcomputer 1 may send a signal prohibiting the equalization processing to the equalization circuit 4 when the equalization processing condition is not satisfied.

The microcomputer 1 functions as an equalization determination unit that determines whether or not to carry out the equalization processing according to whether the equalization processing condition is satisfied or not. When the difference between the maximum voltage measurement value and the minimum voltage measurement value measured by a predetermined battery group among the plurality of battery groups is smaller than the determination threshold value, the microcomputer 1 determines that the equalization process is not performed. When the difference between the above-mentioned maximum voltage measurement value and the minimum voltage measurement value is larger than the determination threshold value, the microcomputer 1 determines to perform the equalization process.

The control device in this specification may also be referred to as an electronic control unit (ECU). The control device or control system is provided by (a) an algorithm as multiple logics called if-then-else form, or (b) a trained model tuned by machine learning, for example, an algorithm as a neural network. ..

The control device is provided by a control system including at least one computer. The control system may include multiple computers linked by data communication equipment. A computer includes at least one processor (hardware processor) which is hardware. The hardware processor can be provided by (i), (ii), or (iii) below.

(I) The hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. The processor core is referred to as a CPU: Central Processing Unit, a GPU: Graphics Processing Unit, RISC-CPU, or the like. Memory is also called a storage medium. Memory is a non-transitional and substantive storage medium that stores "programs and / or data" that can be read by a processor non-temporarily. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, or the like. The program may be distributed by itself or as a storage medium in which the program is stored.

(Ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit containing a large number of programmed logic units (gate circuits). The digital circuit is a logic circuit array, for example, ASIC: ASIC: Application-Specific Integrated Circuit, FPGA: Field Programmable Gate Array, SoC: System on a Chip, PGA: Program Digital circuits may include memory for storing programs and / or data. Computers may be provided by analog circuits. Computers may be provided by a combination of digital and analog circuits.

(Iii) The hardware processor may be a combination of the above (i) and the above (ii). (I) and (ii) are arranged on different chips or on a common chip. In these cases, the part (ii) is also referred to as an accelerator.

The control device, the signal source, and the controlled object provide various elements. At least some of those elements can be called blocks, modules, or sections. Moreover, the elements contained in the control system are called functional means only if they are intentional.

Next, the control related to the battery management of the control device 10 will be described with reference to the flowchart of FIG. In this description, in order to clarify which component included in the control device 10 is the process to be executed, the subject of the sentence explaining the process is, if necessary, the process is performed on behalf of the control device 10. The components of the control device 10 to be executed are described. Further, in the drawing, the start is indicated by S and the end is indicated by E.

When the power of the control device 10 is turned on in step S100, the control device 10 determines in step S110 whether or not the voltage measurement condition is satisfied. In step S110, the control device 10 determines that there is no influence of noise when the motor or engine that generates the power to drive the vehicle is stopped and the assembled battery 5 is not charged or discharged. For example, when the ignition switch or the motor start switch is in the off state, the control device 10 determines that the motor or the engine is in the stopped state.

The control device 10 determines that charging / discharging of the battery is stopped, for example, when the inlet of the vehicle and the connector of the charging terminal 11 are not connected. When the inlet of the vehicle and the connector of the charging terminal 11 are not connected, the control device 10 determines that the charging / discharging of the assembled battery 5 is stopped. For example, when the system main relay 6 is in the off state and the charging terminal 11 and the assembled battery 5 are not energized, the control device 10 determines that the charging / discharging of the assembled battery 5 is stopped. The control device 10 determines that the voltage measurement condition is satisfied when the power device of the vehicle is in the stopped state and the charging / discharging of the assembled battery 5 is stopped. When the voltage measurement condition is satisfied, the control device 10 determines that noise is acceptable.

If it is determined in step S110 that the voltage measurement condition is not satisfied, the control device 10 ends the flowchart of FIG. If it is determined in step S110 that the voltage measurement condition is satisfied, the control device 10 proceeds to step S120. In step S120, the control device 10 determines whether or not there is a failure in the electric circuit in the battery management device 100. The control device 10 has a function as a failure determination unit for determining whether or not there is a failure in the electric circuit in the battery management device 100. If it is determined in step S120 that there is a failure in the electric circuit, the control device 10 ends the flowchart of FIG. 4 without performing the process of setting the limited measurement range.

If it is determined in step S120 that there is no failure of the electric circuit, the control device 10 proceeds to step S130. In step S130, the control device 10 determines whether or not the voltage value (cell voltage) of each battery cell 7 has an idea. If the approximate value of the current voltage value is known, the control device 10 determines in step S130 that it has an idea. For example, when the voltage value is stored in the storage unit 22, the control device 10 determines in step S130 that it has an idea.

If it is determined in step S130 that there is an idea, the control device 10 proceeds to step S140. If it is determined in step S130 that there is no idea, the control device 10 proceeds to step S150.

If it is determined that the voltage value of each battery cell 7 has an idea, the microcomputer 1 outputs a command for detecting the voltage of the battery cell 7 in a limited range to the monitoring IC 3 as a limiting command in step S140. The command unit 31 controls the analog-to-digital converter 32 and the level shifter 33 based on the restriction command to control the input range, gain, and offset. As a result, the limited measurement range of the battery cell 7 is set.

When the process proceeds to step S160 via step S140, the monitoring IC 3 of the control device 10 measures the voltage of the battery cell 7 in the limited measurement range set in step S150, and outputs the measured voltage measurement value to the microcomputer 1. The microcomputer 1 acquires the voltage measured in this limited measurement range and stores it in the storage unit 22. Then, the control device 10 proceeds to step S180.

When it is determined that the voltage value of each battery cell 7 has no idea by tracing back the flow, the microcomputer 1 sets the command for detecting the voltage of the battery cell 7 in the entire range to the monitoring IC 3 as an unrestricted command in step S150. Output. The command unit 31 controls the analog-to-digital converter 32 and the level shifter 33 based on the unrestricted command to control the input range, gain, and offset. As a result, the voltage measurement range in the entire range of the battery cell 7 is set.

Upon receiving the unrestricted command, the monitoring IC 3 measures the voltage of the battery cell 7 in the entire range in step S170, and outputs the measured voltage measurement value to the microcomputer 1. The microcomputer 1 acquires the voltage measured in this entire range and stores it in the storage unit 22. Next, the control device 10 proceeds to step S180.

In step S180, the microcomputer 1 determines whether or not to carry out the equalization process for the battery group. In step S180, the microcomputer 1 equalizes according to whether or not the voltage difference, which is the difference between the maximum voltage measurement value and the minimum voltage measurement value related to the plurality of battery cells 7 included in the battery group, is larger than the determination threshold value. Determine if the process is to be performed. When the voltage difference described above is smaller than the determination threshold value, the microcomputer 1 ends the flowchart of FIG. 4 without performing the equalization process. When the voltage difference described above is larger than the determination threshold value, the microcomputer 1 determines that the equalization process is necessary. The microcomputer 1 controls the equalization circuit 4 in step S190 to carry out the equalization process. When the voltage difference described above is smaller than the determination threshold value, the microcomputer 1 determines that the equalization process is unnecessary.

The determination process in step S110 may be performed as follows. In step S110, when the power device that provides the driving force of the vehicle is stopped, the charging / discharging of the assembled battery 5 is stopped, or the system main relay 6 is off, the microcomputer 1 is set. Judge that the situation is acceptable for noise. In step S110, when it is determined that the noise is acceptable, the microcomputer 1 determines the noise level and determines whether or not the noise level is acceptable. If it is determined that the noise level is acceptable, the microcomputer 1 proceeds to step S120. In this way, the microcomputer 1 may determine that the voltage measurement condition is satisfied when the noise level is acceptable in a situation where noise is acceptable. When the SN ratio, which is the ratio of the signal and the noise, is equal to or higher than the specified value, the control device 10 determines that the noise is acceptable. When the SN ratio is equal to or less than the specified value, the influence of noise on the signal for voltage detection becomes large, and the influence on the voltage detection error becomes large. The source of noise is, for example, an in-vehicle load or an external device connected to the assembled battery 5 such as a power device.

The operation and effect brought about by the battery management device 100 of the first embodiment will be described. The battery management device 100 includes a range setting unit that sets a limited measurement range that limits the voltage measurement range for the battery cell 7 included in the in-vehicle assembled battery 5, and a battery cell 7 in the limited measurement range set by the range setting unit. It is equipped with a measuring unit that measures the voltage of. According to this, an appropriate voltage measurement range is set in order to improve the accuracy of voltage measurement. By improving the accuracy of voltage measurement, it is possible to contribute to these highly accurate estimations when performing SOC estimation and SOH estimation using voltage measurement.

For example, the battery management device 100 narrows the voltage measurement range of the battery cell 7 from the entire range of 0.0V to 5.0V to the limited measurement range of 3.0V to 3.5V. In this limited measurement range, the voltage of the battery cell 7 of the analog electric signal is converted into a digital electric signal by the analog digital converter 32. This reduces the quantization error of the analog-digital converter 32. In the case of the above example, the quantization error is about 1/10. This improves the voltage detection accuracy of the battery cell 7.

The monitoring IC 3 adjusts the voltage measurement range according to the command output from the microcomputer 1 to set the limited measurement range. According to this, it is possible to carry out appropriate voltage measurement with one control device 10 for a plurality of battery cells 7 having different open circuit voltage ranges.

The range setting unit of the battery management device 100 sets a limited measurement range adjusted based on the voltage value of the battery cell 7 when the voltage value of the battery cell 7 is estimated. When the range setting unit of the battery management device 100 has no idea about the voltage value of the battery cell 7, the range setting unit sets a limited measurement range based on the voltage measurement values performed for the voltage in the entire range. For example, when the voltage value of the battery cell 7 is not stored, the range setting unit of the battery management device 100 sets a limited measurement range based on the voltage measurement values performed for the voltage in the entire range. According to this, after confirming the open circuit voltage of the battery cell 7 to be measured, the limited measurement range is set based on the confirmed measured value. According to this setting, an appropriate voltage measurement range that brings about an improvement in the accuracy of voltage measurement is set.

The range setting unit of the battery management device 100 sets a limited measurement range by using at least one of the maximum value and the minimum value of the voltage measurement values measured for the entire voltage range. According to this, the voltage measurement range is set to the limited measurement range in which the voltage value in the current state is reflected. This improves the accuracy of voltage measurement.

The range setting unit sets a limited measurement range when the noise level is an acceptable noise level in an acceptable situation. The measuring unit measures the voltage of the battery cell 7 in this limited measurement range. According to this, the voltage is measured in the limited measurement range set when the noise level is acceptable in a state where the influence of noise is small. Therefore, the battery management device 100 can perform voltage measurement by separating noise and a signal, and further contributes to improvement of voltage measurement accuracy.

The range setting unit sets a limited measurement range when the power device that provides the driving force of the vehicle is in the stopped state and the charging / discharging to the assembled battery 5 is stopped. The measuring unit measures the voltage of the battery cell 7 in the limited measurement range set in this way. According to this, since the voltage is measured in the limited measurement range set in a state where the influence of noise is small, the voltage measurement in which the noise and the signal are separated is performed. Therefore, the battery management device 100 further contributes to the improvement of the voltage measurement accuracy.

The battery management device 100 includes an equalization determination unit for determining whether or not to carry out an equalization process for reducing voltage variations of a plurality of battery cells 7 included in a predetermined battery group among the plurality of battery groups. This equalization determination unit determines whether or not to perform the equalization process based on the voltage measurement value of the battery cell 7 measured in the limited measurement range. According to this, it is possible to determine the implementation of the high-precision equalization process based on the high-precision voltage measurement value measured in the limited measurement range.

The battery management device 100 includes an SOC estimation unit that estimates the storage rate based on characteristic data showing the relationship between the open circuit voltage and the storage rate and the voltage measurement value of the battery cell 7 measured in the limited measurement range. According to this, high-precision SOC estimation can be performed by estimation based on high-precision voltage measurement values measured in a limited measurement range.

<Second Embodiment>
The second embodiment will be described with reference to FIGS. 5 and 6. The control related to the battery management of the second embodiment will be described with reference to FIGS. 5 and 6. The configurations, actions, and effects that are not particularly described in the second embodiment are the same as those in the first embodiment, and only the differences from the first embodiment will be described below.

The control related to the battery management of the second embodiment differs from the control related to the battery management of the first embodiment only in the SOC estimation step, the determination step related to the SOH estimation, and the implementation step. In steps S200 to S270 in the flowchart shown in FIG. 5, the same processing as in steps S100 to S170 shown in FIG. 4 is performed.

As shown in FIG. 5, after the voltage measurement is performed in step S260 or step S270, the control device 10 executes the process of estimating the SOC in step S280 as described above. The microcomputer 1 estimates the SOC by calculating the SOC using the measured voltage value and the above-mentioned characteristic data.

In step S290, the microcomputer 1 determines whether or not the condition for estimating the SOH indicating the degree of deterioration of the battery cell 7 (SOH estimation condition) is satisfied. The microcomputer 1 determines that the SOH estimation condition is satisfied when, for example, a predetermined time has elapsed from the ignition switch and the motor start switch being turned off at the timing of voltage measurement used for SOC estimation. In this case, since the battery polarization is relaxed, the microcomputer 1 permits the SOH estimation.

If it is determined in step S290 that the SOH estimation condition is not satisfied, the flowchart of FIG. 5 ends without estimating the SOH. If it is determined in step S290 that the SOH estimation condition is satisfied, the microcomputer 1 estimates SOH in step S300 and ends the flowchart of FIG. The microcomputer 1 functions as an SOH estimation unit that estimates SOH.

It is preferable that the microcomputer 1 calculates SOH (%) by an operation using the following mathematical formula (1) to estimate SOH.

FIG. 6 shows the characteristic data relating to the battery cell 7 and the operation for obtaining the SOH estimation. As shown in FIG. 6, SOC1 and SOC2 are estimated values of SOC estimated using high-precision voltage measurement values measured in a limited measurement range set by the microcomputer 1. The integrated value of I is calculated by integrating the values of the currents from SOC1 to SOC2. The initial full charge capacity is the full charge capacity at the time of manufacturing the battery cell 7, in other words, the full charge capacity at which deterioration has not started.

The battery management device 100 may perform the determination process of step S290 by the following method. The microcomputer 1 may determine that the SOH estimation condition is satisfied when the measurement error of the voltage measuring device is smaller than the reference value. The microcomputer 1 may determine that the SOH estimation condition is satisfied when the measurement error of the current measuring device is smaller than the reference value. The microcomputer 1 may determine that the SOH estimation condition is satisfied when the voltage measuring device and the current measuring device are operating normally.

<Third Embodiment>
The third embodiment will be described with reference to FIG. 7. The control related to the battery management of the third embodiment will be described with reference to FIG. 7. The configurations, actions, and effects that are not particularly described in the third embodiment are the same as those in the first embodiment, and only the differences from the first embodiment will be described below.

The control related to the battery management of the third embodiment is different from the control of the first embodiment in that at least a part of step S110 is subdivided into steps S112, S114, and S116. In the flowchart of FIG. 7, the same steps as the steps shown in FIG. 4 are designated by the same step reference numerals.

As shown in FIG. 7, in step S112, the microcomputer 1 determines whether or not there is an influence of noise. If it is determined that there is no influence of noise, the microcomputer 1 proceeds to step S120. When it is determined that there is an influence of noise, the microcomputer 1 executes the determination process of step S114.

In step S114, the control device 10 determines whether or not charging from the external device is currently being performed or is being prepared for the assembled battery 5. The external device is, for example, a charging facility 12. External equipment includes equipment that outputs AC power supplied from a small power generation facility or wide area power grid. External devices include power storage facilities that output DC power, storage batteries, and the like.

If it is determined in step S114 that charging is in progress or charging is not being prepared, the control device 10 ends the flowchart of FIG. 7. If it is determined in step S114 that charging or preparation for charging is in progress, the control device 10 executes a process of stopping charging or a process of stopping charging preparation in step S116. After the charging is stopped by step S116, the control device 10 executes the processes after step S120 as described above. According to the steps of S114 and S116, when the assembled battery 5 is being charged or is being prepared for charging, by stopping the charging, it is possible to reduce the influence of noise. As a result, a limited measurement range that enables highly accurate voltage measurement is set.

The third embodiment has the following effects. When the assembled battery 5 is being charged from an external power source, the range setting unit sets a limited measurement range and the measurement unit measures the battery voltage in the limited measurement range while the charging is temporarily stopped. According to this control, the battery management device 100 that can provide an opportunity for performing high-precision voltage measurement even while the assembled battery 5 is being charged from an external device can be obtained.

<Fourth Embodiment>
The fourth embodiment will be described with reference to FIG. The control related to the battery management of the fourth embodiment will be described with reference to FIG. The configurations, actions, and effects that are not particularly described in the fourth embodiment are the same as those in the first embodiment, and only the differences from the first embodiment will be described below.

The control according to the battery management of the fourth embodiment is different from the control of the first embodiment in that it has the steps of S162, S164, and S166. In the flowchart of FIG. 8, the same steps as the steps shown in FIG. 4 are designated by the same step reference numerals.

As shown in FIG. 8, after measuring the voltage in the limited measurement range in step S160, the control device 10 executes the determination process in step S162. In step S162, the microcomputer 1 of the control device 10 functions as an equalization determination unit that determines a correction value of the determination threshold value used in the determination in step S180 according to the width of the limited measurement range set. When the width of the limited measurement range is larger than the predetermined range width stored in the storage unit 22, the microcomputer 1 greatly corrects the determination threshold value. When the width of the limited measurement range is smaller than the predetermined range width, the microcomputer 1 corrects the determination threshold value to be small.

If the width of the limited measurement range is larger than the predetermined range width, the microcomputer 1 proceeds to step S164. The microcomputer 1 executes a process of determining the determination threshold value largely corrected in step S164. In step S180, the microcomputer 1 determines whether or not the equalization process is performed depending on whether or not the voltage difference described above is larger than the largely corrected determination threshold value. When the determination threshold value is largely corrected in step S164, the equalization process tends not to be performed before the correction.

If the width of the limited measurement range is smaller than the predetermined range width, the microcomputer 1 proceeds to step S166. The microcomputer 1 executes a process of determining the determination threshold value corrected to be small in step S166. In step S180, the microcomputer 1 determines whether or not the equalization process is performed depending on whether or not the voltage difference described above is larger than the small corrected determination threshold value. When the determination threshold value is corrected to be small in step S166, the equalization process is likely to be performed before the correction.

The microcomputer 1 may set the determination threshold value according to the width of the limited measurement range by the following method. The microcomputer 1 multiplys the width of the limited measurement range by a coefficient, and corrects the determination threshold value to be smaller as the width of the limited measurement range calculated in this way is smaller. The microcomputer 1 corrects the determination threshold value as the width of the limited measurement range calculated in this way becomes larger. When the difference between the maximum voltage measurement value and the minimum voltage measurement value measured for a predetermined battery group is smaller than this determination threshold value, the microcomputer 1 determines that the equalization process is not performed. When the difference between the above-mentioned maximum voltage measurement value and the minimum voltage measurement value is larger than this determination threshold value, the microcomputer 1 determines to perform the equalization process.

The fourth embodiment has the following effects. The microcomputer 1 sets a determination threshold value according to the width of the limited measurement range. According to this control, the necessity of high-precision equalization processing is determined by using the determination threshold value set according to the width of the limited measurement range. As a result, highly accurate equalization processing is performed.

When the width of the limited measurement range is larger than the predetermined range width, the microcomputer 1 greatly corrects the determination threshold value. When the width of the limited measurement range is smaller than the predetermined range width, the microcomputer 1 corrects the determination threshold value to be small. When the difference between the maximum voltage measurement value and the minimum voltage measurement value measured for a predetermined battery group among a plurality of batteries is smaller than the determination threshold value, the microcomputer 1 determines that the equalization process is not performed. When the difference between the above-mentioned maximum voltage measurement value and the minimum voltage measurement value is larger than the determination threshold value, the microcomputer 1 determines to perform the equalization process.

According to this control, high-precision equalization processing can be performed by determining the necessity of equalization processing based on the high-precision voltage measurement value measured in the limited measurement range. Further, by using the judgment threshold value corrected according to the width of the limited measurement range, the necessity of high-precision equalization processing is determined. Therefore, highly accurate equalization processing is performed.

<Fifth Embodiment>
A fifth embodiment will be described with reference to FIG. FIG. 9 is a configuration diagram of the monitoring IC 103. The configurations, actions, and effects that are not particularly described in the fifth embodiment are the same as those in the first embodiment, and only the differences from the first embodiment will be described below.

The monitoring IC 103 of the fifth embodiment includes a command unit 31, a plurality of analog-to-digital converters 32, a plurality of level shifters 33, and a switch group 34. The monitoring IC 103 further includes a equalization circuit 4. The analog-digital converter 32 and the level shifter 33 are provided so as to correspond to each other.

The monitoring IC 103 has a function of setting a plurality of different limited measurement ranges by a configuration including a plurality of analog-to-digital converters 32 for one switch group 34. The monitoring IC 103 functions as a measuring unit that measures the voltage of the battery cell 7 in a plurality of set limited measurement ranges. Each analog-to-digital converter 32 may be configured to have a function of setting a predetermined limited measurement range. In this case, the plurality of analog-to-digital converters 32 and the level shifter 33 provided corresponding to one battery group are configured to set different predetermined limited measurement ranges.

The range setting unit of the fifth embodiment sets a plurality of different limited measurement ranges. According to this, appropriate voltage measurement is performed for a plurality of battery cells 7.

Further, the monitoring IC 103 includes a plurality of level shifters 33 and an analog-to-digital converter 32 for one switch group 34. Therefore, the voltage of the plurality of battery cells 7 can be measured quickly.

As a matter of course, when the switch group 34 selects the voltage of each of the plurality of battery cells 7, the voltage measurement range of each of the plurality of battery cells 7 is set by the analog-digital converter 32 and the level shifter 33. It may be set individually. Such a configuration is applicable to all embodiments and modifications.

Further, when the switch group 34 selects the voltage of the plurality of battery cells 7 included in the battery group, the analog-digital converter 32 and the level shifter 33 set a common voltage measurement range for at least a part of the plurality of battery cells 7. It may be set with. In such a configuration, a common voltage measurement range may be set as a limited measurement range based on at least one of the maximum value and the minimum value of the voltage measured by the plurality of selected battery cells 7. Such a configuration is applicable to all embodiments and modifications.

<Sixth Embodiment>
The sixth embodiment will be described with reference to FIGS. 10 to 12.

In the first embodiment, an example is shown in which the microcomputer 1 sets the voltage measurement range of the battery cell 7 when the power device of the vehicle is in the stopped state. An example is shown in which the microcomputer 1 sets the voltage measurement range of the battery cell 7 when the ignition switch of the vehicle is in the off state.

On the other hand, in the present embodiment, the microcomputer 1 sets the voltage measurement range of the battery cell 7 when the ignition switch of the vehicle is in the ON state. The microcomputer 1 executes the setting of the voltage measurement range and the voltage detection as a cycle task.

First, the voltage detection of the battery cell 7 will be described in detail with reference to FIG. FIG. 10 shows the time change of the voltage of the battery cell 7. The vertical axis is an arbitrary unit. The horizontal axis is time. Arbitrary units are a. u. It is written in. The time is indicated by T.

The battery cell 7 has an internal resistance. Therefore, there is a difference between the internal resistance and the voltage drop according to the current flowing through the battery cell 7 between the open circuit voltage corresponding to the SOC of the battery cell 7 and the closed circuit voltage detected by the monitoring IC 3. In the following, the voltage of the battery cell 7 detected by the monitoring IC 3 will be unified with the closed circuit voltage.

In addition to the closed circuit voltage, FIG. 10 shows the drive state of the battery management device 100, the actual current flowing through the assembled battery 5, and the closed circuit voltage of one battery cell 7. The drive state of the battery management device 100 is described as DS. For the sake of simplicity, the behavior of the closed circuit voltage of the battery cell 7 and the behavior of the closed circuit voltage of the assembled battery 5 shown in the drawings are the same. In order to clarify the behavior, the drawing shows that the closed circuit voltage of the battery cell 7 changes significantly in a short time.

In the initial state of time 0, the ignition switch of the vehicle is turned off. The battery management device 100 is in a non-driving state. Battery information such as the closed circuit voltage is not stored in the storage unit 22. The system main relay 6 that controls the conduction state between the assembled battery 5 and various in-vehicle devices is in the cutoff state. Therefore, no current is substantially flowing through the assembled battery 5. The closed circuit voltage of the battery cell 7 is a value in the low change region.

Even if no current is flowing through the battery cell 7, the SOC of the battery cell 7 decreases due to self-discharge. Therefore, in the initial state of time 0, the closing voltage of the battery cell 7 tends to decrease, albeit in a small amount.

At time t0, the ignition switch of the vehicle changes from the off state to the on state. The battery management device 100 changes from the non-driving state to the driving state. The system main relay 6 goes from the cutoff state to the energized state. As a result, the supply of power supply power from the assembled battery 5 to various in-vehicle devices starts. The actual current begins to flow in the assembled battery 5. The rate of decrease in SOC of the battery cell 7 increases. Along with this, the rate of decrease in the closed circuit voltage of the battery cell 7 also increases.

At time t1, the microcomputer 1 acquires the closed voltage of the battery cell 7. At this time, the battery information is not stored in the storage unit 22. Therefore, the microcomputer 1 sets the voltage measurement range at time t1 to the entire range. That is, the microcomputer 1 sets the voltage measurement range to 0.0V to 5.0V.

At time t2, the microcomputer 1 again acquires the closed voltage of the battery cell 7. At this time, the microcomputer 1 determines the center value of the limited measurement range at the time t2 based on the closed circuit voltage of the battery cell 7 acquired at the time t1. Further, the microcomputer 1 determines the range width α of the limited measurement range.

The voltage measurement range is indicated by the width of the arrows on both ends of the solid line shown in FIG. The difference between the center value and the upper and lower limit values of the limited measurement range is set in the range width α. The range width α is a value larger than the detection error of the closed circuit voltage. The range width α is a value smaller than half of the difference between OCV1 and OCV2 shown in FIG. The difference between the center value and the upper limit value and the difference between the center value and the lower limit value may be the same or different. In this embodiment, the range width α is set to a fixed value. The range width α is stored in the storage unit 22. Therefore, the limited measurement range is substantially determined based on the closed circuit voltage. The microcomputer 1 sets a limited measurement range based on this range width α and the acquired closed circuit voltage. The microcomputer 1 sets, for example, the limited measurement range of the time t2 to 2.8V to 3.2V. The microcomputer 1 acquires the closed circuit voltage detected by the monitoring IC 3 in the limited measurement range at this time t2.

Strictly speaking, since there is arithmetic processing in the battery management device 100, the determination timing of the limited measurement range and the acquisition timing of the closed circuit voltage in the time t2 are not the same. The decision timing is before the acquisition timing. However, the difference between these two timings is small. Therefore, these two timings are regarded as the same and described.

The microcomputer 1 acquires the cycle closed voltage in the acquisition cycle. This acquisition cycle is an expected time interval in which the SOC of the battery cell 7 does not change suddenly unless the charge / discharge state of the battery cell 7 suddenly changes due to rapid charging or the like. The acquisition cycle is a time interval in which it is expected that the amount of change in the closed circuit voltage of the battery cell 7 does not exceed the range width α. When the acquisition cycle elapses from the time t1, the time t2 is reached.

When the acquisition cycle elapses from the time t2 and reaches the time t3, the microcomputer 1 determines the limited measurement range based on the closed circuit voltage at the time t2. The microcomputer 1 sets, for example, the limited measurement range of the time t3 to 2.6V to 3.0V. Then, the microcomputer 1 acquires the closed circuit voltage of the battery cell 7 detected by the monitoring IC 3 in this limited measurement range.

When the time t3 changes to the time tc1, the driving state of the vehicle changes. The actual current is reduced. Along with this, the reduction rate of the closed circuit voltage is also reduced.

When the acquisition cycle elapses from the time t3 and reaches the time t4, the microcomputer 1 determines the limited measurement range based on the closed circuit voltage at the time t3. The microcomputer 1 sets, for example, the detection range of the time t4 to 2.4V to 2.8V. The microcomputer 1 acquires the closed circuit voltage of the battery cell 7 detected by the monitoring IC 3 in this limited measurement range.

From time t4 to time ct2, the charging equipment 12 is connected to the vehicle via the charging terminal 11. The assembled battery 5 is quickly charged by the charging equipment 12. As a result, the actual current rises sharply. The microcomputer 1 acquires the information from the charging equipment 12. At this time, the microcomputer 1 sets the voltage measurement range to the entire range.

When the acquisition cycle elapses from the time t4 and reaches the time t5, the microcomputer 1 acquires the closed circuit voltage of the battery cell 7 detected by the monitoring IC 3 in the entire range. Due to the change in the voltage measurement range, as shown in FIG. 10, even if the closed circuit voltage suddenly rises from the time tc2, the closed circuit voltage detected at the time t5 is within the voltage measurement range.

From the time t5 to the time tk3, the output voltage of the assembled battery 5 reaches the target voltage. When this is detected, the microcomputer 1 ends the quick charging by the charging equipment 12. The microcomputer 1 causes the charging equipment 12 to perform a full charge.

The amount of supply current differs between the above-mentioned quick charge and full charge. Fast charging has a larger supply current than full charging.

There is a difference in voltage drop between the closed circuit voltage and the open circuit voltage. Therefore, for example, even if the maximum output voltage of the assembled battery 5 is detected as the closed circuit voltage, the open circuit voltage does not reach the maximum output voltage. The SOC of the assembled battery 5 has not reached the full charge capacity.

The above target voltage is a value based on the maximum output voltage of the assembled battery 5. When the microcomputer 1 determines that the output voltage of the assembled battery 5 has reached the target voltage, the microcomputer 1 causes the charging equipment 12 to fully charge the battery. In full charge, charging power is supplied to the assembled battery 5 while keeping the output voltage of the assembled battery 5 at the target voltage in order to bring the SOC of the assembled battery 5 closer to the full charge capacity while avoiding overcharging. .. The target voltage and the maximum output voltage are stored in advance in the storage unit 22.

When the acquisition cycle elapses from the time t5 and reaches the time t6, the microcomputer 1 acquires the closed circuit voltage of the battery cell 7 detected by the monitoring IC 3 in the entire range. Of course, at this time, it is expected that the output voltage of the assembled battery 5 has reached the target voltage. Therefore, the closed circuit voltage may be detected in the voltage measurement range based on this target voltage.

(7th Embodiment)
The seventh embodiment will be described with reference to FIG.

In the sixth embodiment, as described with reference to FIG. 10, when the non-driving state is switched to the driving state, the microcomputer 1 shows an example of acquiring the closed circuit voltage detected by the monitoring IC 3 in the entire range. rice field.

On the other hand, in the present embodiment, when the non-driving state is switched to the driving state, the microcomputer 1 acquires the closed circuit voltage detected by the monitoring IC 3 in the usable range of the battery cell 7. According to this, even when the battery management device 100 is switched from the non-driving state to the driving state, the detection accuracy of the closed circuit voltage can be improved.

For example, at the time t0 shown in FIG. 11, the battery management device 100 changes from the non-driving state to the driving state. The system main relay 6 goes from the cutoff state to the energized state. Current begins to flow in the assembled battery 5. The reduction rates of the SOC and the closed circuit voltage of the battery cell 7 are increased.

From time t0 to time t1, the microcomputer 1 sets a limited measurement range based on the characteristic data of SOC and OCV shown in FIG. The microcomputer 1 sets, for example, the usable range of the battery cell 7 between SOC1 and SOC2 shown in FIG. Then, the microcomputer 1 sets a limited measurement range based on the OCV1 and the OCV2 corresponding to the SOC1 and the SOC2. As shown in FIG. 11, the microcomputer 1 sets the lower limit value of the limited measurement range to CCV1 and the upper limit value to CCV2.

The characteristic data shown in FIG. 6 depends on the temperature. And there is a difference in voltage drop between the open circuit voltage and the closed circuit voltage. Therefore, the microcomputer 1 may set a limited measurement range in consideration of not only the characteristic data shown in FIG. 6 but also the temperature, current, deterioration degree, etc. of the battery cell 7 at time t1.

In order to clarify the distinction from the entire range described in the other embodiments, it is described in the present embodiment that the microcomputer 1 sets the voltage measurement range at time t1 to the limited measurement range as described above. bottom. However, the battery cell 7 is used within the usable range in the first place. Therefore, the cycle voltage detected is expected to be within this usable range. Therefore, the usable range may be set to the entire range in the first place. Such settings can also be applied to other embodiments and modifications.

(8th Embodiment)
The eighth embodiment will be described with reference to FIG.

In the embodiments so far, the microcomputer 1 has shown an example of acquiring the closed circuit voltage of each of the plurality of battery cells 7 regardless of the implementation of the equalization process. On the other hand, in the present embodiment, after the equalization process is performed, the microcomputer 1 acquires the closed circuit voltage of a part of the plurality of battery cells 7.

When the equalization process is performed, the SOCs of each of the plurality of battery cells 7 are equalized. Therefore, it is expected that the closed voltage of each of the plurality of battery cells 7 is the same. Therefore, after the equalization process is performed, the monitoring IC 3 detects the closed circuit voltage of a part of the plurality of battery cells 7. The microcomputer 1 acquires the closed circuit voltage detected by the monitoring IC 3. This simplifies the arithmetic processing of the monitoring IC 3 and the microcomputer 1.

The monitoring IC 3 may detect all the closed circuit voltages of the plurality of battery cells 7. Then, the microcomputer 1 may acquire a part of the plurality of closed circuit voltages detected by the monitoring IC 3. This simplifies the arithmetic processing of the microcomputer 1.

However, after a certain amount of time has passed since the equalization was performed, the SOCs of the plurality of battery cells 7 vary. The closing voltage of each of the plurality of battery cells 7 becomes different.

Therefore, the microcomputer 1 executes the acquisition target setting process shown in FIG. The microcomputer 1 executes this acquisition target setting process as a cycle task. The microcomputer 1 executes this acquisition target setting process in parallel with other battery management shown in, for example, FIGS. 4 and 10.

In step S310, the microcomputer 1 determines whether or not the equalization counter owned by the microcomputer 1 is smaller than the expected variation value stored in the storage unit 22. If it is determined that the equalization counter is smaller than the expected variation value, the microcomputer 1 proceeds to step S320. If the equalization counter determines that the variation is equal to or greater than the expected variation value, the microcomputer 1 proceeds to step S330.

The value of the equalization counter is cleared when the equalization process is executed. The expected variation value is determined based on the time when the closing voltages of the plurality of battery cells 7 are expected to be inconsistent after the equalization process is executed.

Proceeding to step S320, the microcomputer 1 increments the equalization counter. Then, the microcomputer 1 proceeds to step S340.

When the process proceeds to step S340, the microcomputer 1 sets only a part of the plurality of battery cells 7 for which the equalization process has been executed as the acquisition target (voltage measurement target) of the closed circuit voltage. For example, the microcomputer 1 makes one of a plurality of battery cells 7 included in one battery group a target for acquiring a closed circuit voltage. For example, the microcomputer 1 makes one of all the battery cells 7 included in the plurality of battery groups a target for acquiring the closed circuit voltage. Then, the microcomputer 1 ends the acquisition target setting process.

When it is determined in step S310 that the equalization counter is equal to or greater than the expected variation value and the process proceeds to step S330, the microcomputer 1 makes all of the plurality of battery cells 7 the acquisition target of the closed circuit voltage. After this, the microcomputer 1 ends the acquisition target setting process.

After the equalization process is executed, the microcomputer 1 repeatedly executes steps S310, S320, and S340. During this period, only a part of the closed circuit voltage of the plurality of battery cells 7 for which the equalization process has been executed is set as the acquisition target.

After that, when the equalization counter reaches the expected variation value, the microcomputer 1 repeatedly executes step S330. After that, all of the closed circuit voltages of the plurality of battery cells 7 are set as acquisition targets until the equalization process is executed again.

<Other embodiments>
Disclosure of this specification is not limited to the exemplary embodiments. Disclosures include exemplary embodiments and modifications by those skilled in the art based on them. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiment, and can be variously modified and carried out. Disclosure can be carried out in various combinations. The disclosure can have additional parts that can be added to the embodiment. The disclosure includes the parts and elements of the embodiment omitted. Disclosures include replacements or combinations of parts, elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. The technical scope disclosed is indicated by the description of the scope of claims and should be understood to include all modifications within the meaning and scope equivalent to the description of the scope of claims.

(Other variants)
The battery management device 100 capable of achieving the object disclosed in the specification is not limited to the configuration in which the monitoring IC 3 is provided for each battery group. The battery management device 100 may be configured to have a monitoring IC 3 and a microcomputer 1 with respect to the assembled battery 5. The battery management device 100 may be configured to include one microcomputer 1 for each battery group.

1 ... Microcomputer (range setting unit, equalization judgment unit, SOC estimation unit, SOH estimation unit), 3 ... monitoring IC (measurement unit), 5 ... assembled battery, 7 ... battery cell, 12 ... charging equipment (external power supply) , 100 ... Battery management device, 200 ... Battery device

Claims (16)

A range setting unit (1) that sets a limited measurement range that limits the voltage measurement range for a plurality of in-vehicle batteries (7), and
A measuring unit (3; 103) that measures the voltage of the battery in the limited measurement range set by the range setting unit, and
A battery management device equipped with. The battery management device according to claim 1, wherein the measuring unit adjusts the voltage measuring range according to a command output from the range setting unit to set the limited measurement range. The range setting unit is
If there is an idea about the voltage value of the battery, set the limited measurement range adjusted based on the voltage value of the battery.
The battery management device according to claim 1 or 2, wherein when the voltage value of the battery has no idea, the limited measurement range is set based on the voltage measurement value performed for the voltage in the entire range. The battery management device according to claim 3, wherein the range setting unit sets the limited measurement range by using at least one of the maximum value and the minimum value among the voltage measurement values measured for the voltage in the entire range. The battery management device according to any one of claims 1 to 4, wherein the range setting unit is configured to set a plurality of different limited measurement ranges. Claims 1 to claim 1 to claim 1, wherein the range setting unit sets the limited measurement range, and the measurement unit measures the voltage of the battery in the limited measurement range when the noise level is an acceptable noise level in an acceptable situation. The battery management device according to any one of 5. When the power device that provides the driving force of the vehicle is stopped and the charging / discharging to the battery is stopped, the range setting unit sets the limited measurement range, and the measurement unit sets the limited measurement range. The battery management device according to claim 6, wherein the voltage of the battery is measured in the above-mentioned. When the battery is being charged from the external power source (12), the range setting unit sets the limited measurement range, and the measurement unit sets the limited measurement range of the battery in the limited measurement range. The battery management device according to any one of claims 1 to 5, which measures a voltage. It is provided with an equalization determination unit (1) for determining whether or not an equalization process for reducing voltage variation is performed on a predetermined battery group including at least a part of the plurality of the batteries.
The equalization determination unit according to any one of claims 1 to 8 determines whether or not to carry out the equalization process based on the voltage measurement value of the battery measured in the limited measurement range. The battery management device described. It is provided with an equalization determination unit (1) for determining whether or not an equalization process for reducing voltage variation is performed on a predetermined battery group including at least a part of the plurality of the batteries.
The equalization determination unit sets a determination threshold value according to the width of the limited measurement range set by the range setting unit.
When the difference between the maximum voltage measurement value and the minimum voltage measurement value measured for a predetermined battery group including at least a part of the plurality of batteries is smaller than the determination threshold value, the equalization determination unit may perform the above. The battery management device according to any one of claims 1 to 8, wherein it is determined not to perform the equalization process, and if it is larger than the determination threshold value, it is determined to perform the equalization process. When the width of the limited measurement range set by the range setting unit is larger than the predetermined range width, the equalization determination unit greatly corrects the determination threshold value, and the width of the limited measurement range is larger than the predetermined range width. The battery management device according to claim 10, wherein if the value is small, the determination threshold value is corrected to be small. The equalization determination unit claims that when the equalization process is performed on a plurality of the batteries included in the battery group, a part of the plurality of the batteries included in the battery group is targeted for voltage measurement. The battery management device according to any one of claims 9 to 11. The SOC estimation unit (1) for estimating the storage rate based on the characteristic data showing the relationship between the open circuit voltage and the storage rate of the battery and the voltage measurement value of the battery measured in the limited measurement range is provided. The battery management device according to any one of claims 1 to 12. The battery management device according to claim 13, further comprising an SOH estimation unit (1) that estimates SOH indicating the degree of deterioration of the battery using the storage rate estimated by the SOC estimation unit. The battery management device according to any one of claims 1 to 14, wherein the range setting unit sets the voltage measurement range within the usable range of the battery when the non-driving state is switched to the driving state. Multiple in-vehicle batteries (7) and
A range setting unit (1) that sets a limited measurement range that limits the voltage measurement range for the battery, and
A measuring unit (3; 103) that measures the voltage of the battery in the limited measurement range set by the range setting unit, and
Battery device with.

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