JPWO2020084817A1 - Battery monitoring system and physical quantity aggregation method - Google Patents

Abstract

The battery monitoring system includes a plurality of communication devices that acquire physical quantities related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and a battery monitoring device that monitors the charging / discharging of the plurality of unit batteries. .. The communication device acquires from the communication time unit that measures the time, a correction execution unit that corrects the time measured by the communication time unit based on the information related to the correction notified from the battery monitoring device, and the unit battery. The battery monitoring device includes a transmission unit that adds a time measured by the communication time unit to the physical quantity and transmits the time to the battery monitoring device. The battery monitoring device includes a monitoring time unit that measures the time and the monitoring time unit measures the time. Based on the correction information notification unit that notifies the communication device of information related to the correction of the time measured by the communication time unit, and the time when the physical quantity received from the communication device is added to the physical quantity. It is equipped with an aggregation unit that aggregates.

Description

The present disclosure relates to a battery monitoring system and a physical quantity aggregation method. This application claims priority based on Japanese Application No. 2018-202069 filed on October 26, 2018, and incorporates all the matters described in the Japanese application.

Each secondary battery has a limited battery voltage and charge / discharge capacity, but according to an assembled battery in which unit batteries, which are battery modules including the secondary battery, are connected in series, the total battery voltage and charge / discharge capacity are limited. The capacity can be increased. In such an assembled battery, due to differences in characteristics such as internal resistance and deterioration degree of each secondary battery, and differences in usage conditions such as battery temperature, charging is performed between the secondary batteries or unit batteries while charging and discharging are repeated. The balance of the amount (remaining capacity) may be lost.

If charging and discharging are repeated in a state where the charge amount is out of balance due to the above-mentioned causes, the terminal voltage at the time of charging and discharging of each secondary battery or unit battery becomes uneven, and the imbalance is promoted. The difference in internal resistance due to deterioration tends to increase. If the terminal voltage becomes uneven, the battery is charged according to the secondary battery or unit battery having the highest terminal voltage during charging, and discharged according to the secondary battery or unit battery having the lowest terminal voltage during discharging. There must be. In some cases, the capacity balance between each secondary battery or unit battery may be adjusted. In any case, it is important to accurately grasp the battery voltage (hereinafter, also simply referred to as voltage) and charge / discharge current of each secondary battery or unit battery in real time.

On the other hand, Patent Document 1 describes a voltage detection circuit connected to the + and-terminals of each module battery of an assembled battery, and a signal conversion circuit that converts the output of the voltage detection circuit into a digital signal for serial transmission output. , A battery monitoring device including a voltage measuring unit including a modulation / demodulation circuit and a transmission circuit is described. This monitoring device adds the address number of each unit to the voltage data measured by each voltage measuring unit and transmits it to an ECU (Electronic Control Unit) which is a central control device.

Further, Patent Document 2 describes an assembled battery system including a plurality of storage battery modules and a management device that wirelessly communicates with each storage battery module and manages them. The storage battery module includes a plurality of secondary batteries connected in series, a cell monitoring unit that acquires battery information of each secondary battery, a wireless communication unit that wirelessly transmits battery information from the cell monitoring unit, and a control unit. And have. The management device transmits measurement instructions including information for specifying the next measurement timing to each storage battery module at predetermined intervals, causes each cell monitoring unit to acquire battery information all at once in a predetermined measurement slot, and wirelessly. It is controlled so that it is transmitted from the communication unit to the management device.

Japanese Unexamined Patent Publication No. 8-339829 International Publication No. 2014/10008

The battery monitoring system according to one aspect of the present disclosure monitors a plurality of communication devices for acquiring physical quantities related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and charging / discharging of the plurality of unit batteries. A battery monitoring system including a battery monitoring device, wherein the communication device measures the time based on a communication metering unit that measures the time and information related to correction notified from the battery monitoring device. The battery monitoring device includes a correction execution unit that corrects the time and a transmission unit that adds the time measured by the communication metering unit to the physical quantity acquired from the unit battery and transmits the time to the battery monitoring device. From the monitoring metering unit that measures the time, a correction information notification unit that notifies the communication device of information related to the correction of the time measured by the communication metering unit based on the time measured by the monitoring and timing unit, and the communication device. It includes an aggregation unit that aggregates the received physical quantity based on the time added to the physical quantity.

The physical quantity aggregation method according to one aspect of the present disclosure monitors charging / discharging of a plurality of communication devices for acquiring the physical quantity related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and the charging / discharging of the plurality of unit batteries. It is a method of aggregating the physical amount in the battery monitoring device in a battery monitoring system including a battery monitoring device, and based on the information related to the correction notified from the battery monitoring device in the communication device. The battery monitoring device includes a step of correcting the time measured by the communication metering unit and a step of adding the time measured by the communication metering unit to the physical quantity acquired from the unit battery and transmitting the time to the battery monitoring device. In the step of notifying the communication device of information related to the correction of the time measured by the communication meter based on the time measured by the own monitoring time unit, and the physical amount received from the communication device. Includes a step to aggregate based on the time added to.

It should be noted that the present application can be realized not only as a battery monitoring system provided with such a characteristic processing unit or as a physical quantity aggregation method in which characteristic processing is a step, but also as one of the battery monitoring systems. The unit can be realized as a semiconductor integrated circuit or as another system including a battery monitoring system.

FIG. 5 is a block diagram showing a configuration example of a main part of a vehicle equipped with the battery monitoring system according to the first embodiment. It is a block diagram which shows the structural example of the battery monitoring system 1 and the assembled battery which concerns on Embodiment 1. FIG. It is a block diagram which shows the structural example of the MCU which BMU has. It is a block diagram which shows the structural example of MCU which a current detection unit has. It is a block diagram which shows the structural example of the MCU which a battery monitoring device has. It is a graph which shows an example of the waveform of the battery voltage and charge / discharge current of a secondary battery. It is a graph which shows the result of successive estimation of the resistance parameter in the equivalent circuit model of a secondary battery. It is a flowchart which shows the processing procedure of the control part which realizes the function of a timekeeping part in common. It is a flowchart which shows the processing procedure of the control part which realizes the function of the aggregation part. It is explanatory drawing which shows typically the charge / discharge current, the battery voltage and the temperature which were sorted in the order of the start time of the aggregation time. It is a flowchart which shows the processing procedure of the control part which realizes the function of the correction information notification part. It is a flowchart which shows in common the processing procedure of the control part which receives the signal from the battery monitoring device in each of a BMU and a current detection unit. It is a flowchart which shows the processing procedure of the control part which realizes each function of a voltage acquisition part and a current acquisition part in common. It is explanatory drawing which shows the equivalent circuit model of the secondary battery represented by the combination of a resistor and a capacitor. It is a flowchart which shows the processing procedure of the control part which sequentially estimates a parameter by a battery monitoring device. It is a flowchart which shows the processing procedure of the control part which concerns on a subroutine of a current determination. It is a graph which shows the waveform of the battery voltage and charge / discharge current of a secondary battery which estimates a parameter. It is a graph which shows the result of sequentially estimating the parameter of the equivalent circuit model of a secondary battery. It is a block diagram which shows the structural example of the battery monitoring system and the assembled battery which concerns on Embodiment 2. It is a block diagram which shows the structural example of the MCU which a battery monitoring device has. It is a flowchart which shows the processing procedure of the control part which realizes the function of the current acquisition part and a part of the function of an aggregation part. It is a flowchart which shows the processing procedure of the control part which realizes the other part function of the aggregation part. It is a flowchart which shows the processing procedure of the control part which realizes the function of a voltage acquisition part.

[Issues to be disclosed by this disclosure]
However, according to the technique described in Patent Document 1, the voltage data of each module is transmitted to the ECU in order, but the simultaneity is not guaranteed, and the voltage data of each module is acquired at what time. It is unknown. Further, according to the technique described in Patent Document 2, the measurement slots for each storage battery module do not always match in time, and it is unknown at what time in the designated measurement slot the battery information was acquired. There was a problem that it was.

The present disclosure has been made in view of such circumstances, and the purpose of the present disclosure is to set the physical quantity related to charging / discharging obtained from the secondary battery or the unit battery contained in the assembled battery to a common time of the system. It is an object of the present invention to provide a battery monitoring system and a physical quantity aggregation method that can be associated and aggregated in a battery monitoring apparatus.

[Effect of the present disclosure]
According to the disclosure of the present application, it is possible to collect the physical quantities related to charging / discharging acquired from the secondary battery or the unit battery included in the assembled battery in the battery monitoring device in association with the common time of the system.

[Explanation of Embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described. In addition, at least a part of the embodiments described below may be arbitrarily combined.

(1) The battery monitoring system according to one aspect of the present disclosure includes a plurality of communication devices for acquiring physical quantities related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and charging of the plurality of unit batteries. A battery monitoring system including a battery monitoring device for monitoring discharge, wherein the communication device is based on a communication metering unit that measures time and information related to correction notified from the battery monitoring device. The battery monitoring device includes a correction execution unit that corrects the time measured by the battery, and a transmission unit that adds the time measured by the communication metering unit to the physical quantity acquired from the unit battery and transmits the time to the battery monitoring device. Is a monitoring metering unit that measures the time, a correction information notification unit that notifies the communication device of information related to the correction of the time measured by the communication measuring unit based on the time measured by the monitoring measuring unit, and the above. It includes an aggregation unit that aggregates the physical quantity received from the communication device based on the time added to the physical quantity.

(14) The physical quantity aggregation method according to one aspect of the present disclosure includes a plurality of communication devices for acquiring physical quantities related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and charging of the plurality of unit batteries. A method of aggregating the physical quantity in the battery monitoring device in a battery monitoring system including a battery monitoring device for monitoring discharge, based on information related to correction notified from the battery monitoring device in the communication device. The step includes a step of correcting the time measured by the communication metering unit itself, and a step of adding the time measured by the communication metering unit to the physical quantity acquired from the unit battery and transmitting the time to the battery monitoring device. In the battery monitoring device, a step of notifying the communication device of information related to the correction of the time measured by the communication time unit based on the time measured by its own monitoring time unit, and the physical amount received from the communication device. Includes a step of aggregating based on the time added to the physical quantity.

In this embodiment, a plurality of communication devices acquire physical quantities related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and a battery monitoring device monitors the charging / discharging of the plurality of unit batteries. When the battery monitoring device notifies the information related to the time correction based on the time measured by itself, the communication device corrects the time measured by itself based on the notified information. The communication device acquires the physical quantity related to charging / discharging from the unit battery, adds the time measured by itself to the physical quantity, and transmits the physical quantity to the battery monitoring device. The battery monitoring device aggregates the received physical quantities based on the time of reception. As a result, the time referred to when aggregating in the battery monitoring device becomes the time corrected by the notification from the battery monitoring device.

(2) The information related to the correction of the time is the time notified by the correction information notification unit when the time of a predetermined unit changes among the times measured by the monitoring time unit, and the correction execution unit is the time. It is preferable to correct the time measured by the communication time unit to the notified time.

According to this aspect, when the battery monitoring device notifies the communication device of the time when the time of the predetermined unit timed by itself changes, the communication device sets the time measured by itself according to the notified time in the predetermined unit. Round to the time and correct. As a result, the times measured by the battery monitoring device and the communication device are synchronized with each other.

(3) The information relating to the correction of the time is an instruction for correcting the time notified by the correction information notification unit when the time of a predetermined unit measured by the monitoring time unit changes, and the correction execution unit is the same. When notified of the instruction, it is preferable to detect a time lag of less than the predetermined unit measured by the communication time unit and correct the delay or advance of the time measured by the communication time unit.

According to this aspect, when the battery monitoring device notifies the communication device of an instruction to correct the time when the time of a predetermined unit measured by the battery monitoring device changes, the communication device measures the time by itself when the instruction is notified. Detects the time lag of a unit smaller than the unit and corrects the time lag measured by itself. As a result, the communication device converges so that the time measured by the battery monitoring device and the communication device coincide with each other in order to correct the advance or delay of the time measured by the communication device based on the detected time lag.

(4) It is preferable that the battery monitoring device synchronizes the time measured by the monitoring time unit with the time acquired from the outside.

According to this aspect, the time measured by the battery monitoring device is synchronized with the time acquired from the outside. As a result, the time measured by the battery monitoring device follows the time from the outside with high accuracy.

(5) The aggregation cycle in which the aggregation unit aggregates the physical quantity is the same as the acquisition cycle in which the communication device acquires the physical quantity, and the aggregation unit is based on the time when the physical quantity is added to the physical quantity. Therefore, it is preferable that the aggregation is performed in association with the time representing each of the aggregation cycles.

According to this aspect, in the battery monitoring device, the physical quantity related to the charge / discharge acquired in the acquisition cycle of the communication device is subjected to each aggregation cycle having the same length as the acquisition cycle based on the time added to the physical quantity. Are aggregated in association with the representative time. As a result, acquisition and aggregation of physical quantities related to charge / discharge are performed in a one-to-one synchronization, and the aggregation results are sorted in the order of time representing each aggregation cycle.

(6) The battery monitoring device notifies the communication device of the cycle for aggregating the physical quantity, and the communication device acquires the physical quantity at the cycle notified from the battery monitoring device. It is preferable to have.

According to this aspect, the battery monitoring device notifies the communication device of the aggregation cycle, and the communication device acquires the physical quantity related to charging / discharging in the acquisition cycle having the same length as the notified aggregation cycle. As a result, the acquisition cycle of the physical quantity related to charge / discharge can be changed from the battery monitoring device.

(7) The communication time unit measures the time in units of 1 second or more, the first time unit, and the second time unit that clocks less than 1 second in synchronization with the time measured by the first time unit. The correction information notification unit includes the timekeeping unit, and when the time in units of 1 second or more measured by the monitoring timekeeping unit changes, the correction information notification unit notifies the information related to the correction of the time, and the correction execution unit is the first. 1 It is preferable to correct the time measured by the time section.

According to this aspect, among the times measured by the communication time unit in the communication device, the first time unit measures the time in units of 1 second or more, and the second time unit counts the time in units of less than 1 second. Times in synchronization with the timekeeping section. When the battery monitoring device notifies the communication device of information related to the time correction in units of 1 second or more, the communication device corrects the time measured by the first time unit. As a result, a general-purpose real-time clock that clocks the time in units of 1 second or more can be used for the first clock, and when the first clock is corrected by the communication device, the second clock becomes the first clock. It is corrected in synchronization with.

(8) The acquisition cycle is a cycle of 1 / N seconds (N is an integer of 2 or more) measured based on the time measured by the second time section, and the time measured by the first time section. It is preferable to include a cycle whose start time is the same as when the value changes.

According to this aspect, the acquisition cycle is a cycle in which the time corresponding to the N cycle is exactly 1 second, and one cycle of the N cycle starts at the 1-second transition measured by the first timekeeping section. It will be the time. As a result, the physical quantities related to charging / discharging can be aggregated in a cycle shorter than 1 second. Further, when the first time portion of the communication device is corrected, the phases of the acquisition cycle and the aggregation cycle can be matched in the battery monitoring system.

(9) The time added by the communication device is a time in a unit smaller than the unit of time corresponding to the acquisition cycle, and the aggregation unit has the aggregation cycle based on the time when the physical quantity is added to the physical quantity. It is preferable that they are aggregated in association with either the start time or the end time of each.

According to this aspect, when the physical quantity related to charge / discharge is acquired in the acquisition cycle, the communication device adds a time in a unit smaller than the unit of time corresponding to the acquisition cycle. The battery monitoring device aggregates the physical quantities related to charge / discharge acquired by the communication device in association with the start time or end time of each aggregation cycle based on the time added to the physical quantities. As a result, when the time when the physical quantity related to charge / discharge is actually acquired is delayed, the physical quantity related to charge / discharge is aggregated in association with the start time of the next aggregation cycle.

(10) The physical quantity includes the voltage of the secondary battery or the unit battery and the charge / discharge current of the unit battery, and the battery monitoring device is a time-series aggregate of the secondary battery or the unit battery. It is preferable to include an estimation unit that estimates the parameters of the secondary battery or the equivalent circuit model of the unit battery based on the voltage of the unit battery and the charge / discharge current of the unit battery.

According to this aspect, the coefficient of the above relational expression is determined and determined by sequentially applying the time-series aggregated voltage and charge / discharge current to the relational expression expressing the relationship between the battery voltage and the charge / discharge current. Estimate the parameters based on the resulting coefficients.

(11) The battery monitoring device includes an estimation prohibition unit that prohibits estimation of the parameter when the absolute value of the charge / discharge current of the secondary battery or the unit battery aggregated in time series is smaller than the first threshold value. Is preferable.

According to this aspect, if the absolute value of the charge / discharge current is smaller than the first threshold value while estimating the parameters of the secondary battery or the unit battery, the parameters are not estimated. As a result, the parameter update is deferred when there is a high probability that the parameter estimation error will increase.

(12) The battery monitoring device includes an estimation prohibition unit that prohibits estimation of the parameter when the difference between the charge / discharge currents of the secondary battery or the unit battery aggregated in adjacent cycles is smaller than the second threshold value. Is preferable.

According to this aspect, if the difference between the charge / discharge current aggregated in the current aggregation cycle and the charge / discharge current aggregated in the previous aggregation cycle is smaller than the second threshold value, the parameter is not estimated. As a result, the parameter update is deferred when the parameter estimation error is inevitably large.

(13) The communication device may acquire the voltage of the unit battery or the secondary battery contained in the unit battery, and the battery monitoring device may acquire the charge / discharge current of the unit battery and aggregate it in itself. preferable.

According to this aspect, since the battery monitoring device also serves as a communication device for acquiring the charge / discharge current of the unit battery, the number of communication devices is reduced.

[Details of Embodiments of the present disclosure]
Hereinafter, specific examples of the battery monitoring system and the physical quantity aggregation method according to the embodiment of the present disclosure will be described with reference to the drawings. It should be noted that the present invention is not limited to these examples, and is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. Also, the technical features described in each embodiment can be combined with each other.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration example of a main part of a vehicle equipped with the battery monitoring system according to the first embodiment. The vehicle includes an assembled battery 20 formed by combining a plurality of secondary batteries (hereinafter, also referred to as cells) 22, a battery monitoring system 1 for monitoring the assembled battery 20, relays 11, 12, an inverter 13, a motor 14, and a DC. It includes a / DC converter 15, an auxiliary battery 16, an electric load 17, a start switch 18, and a charger 19.

The battery monitoring system 1 includes a battery management unit (BMU: Battery Management Unit) 23 that separately manages a plurality of battery modules (hereinafter, also referred to as unit batteries) included in the assembled battery 20, a current sensor 240, and a current detection unit. 24 and a battery monitoring device 100 that monitors the entire system. The battery monitoring device 100 is communicably connected to each BMU 23 and the current detection unit 24. Although the assembled battery 20 and each BMU 23 are housed in the secondary battery unit 200, each BMU 23 may be outside the secondary battery unit 200. Further, the current sensor 240 may be housed in the secondary battery unit 200, or the current detection unit 24 may be housed in the secondary battery unit 200.

The current sensor 240 is composed of, for example, a shunt resistor or a Hall sensor, and converts the charge current and discharge current (hereinafter referred to as charge / discharge current) of the assembled battery 20 into a voltage signal. The current detection unit 24 detects the charge / discharge current of the assembled battery 20 based on the voltage signal converted from current to voltage by the current sensor 240.

The relay 11 is connected between the positive electrode side of the assembled battery 20, the input side of the inverter 13, and the input side of the DC / DC converter 15. The negative electrode side of the assembled battery 20 is connected to one end of the current sensor 240. The output side of the inverter 13 is connected to one end of the motor 14. The output side of the DC / DC converter 15 is connected to the positive electrode side of the auxiliary battery 16, one end of the electric load 17, and one end of the start switch 18. The relay 12 is connected between the positive electrode side of the assembled battery 20 and the positive electrode side of the charger 19. The other end of the current sensor 240, the other end of the motor 14, the negative electrode side of the auxiliary battery 16, the other end of the electric load 17, and the negative electrode side of the charger 19 are connected to a common potential.

A relay control unit (not shown) turns on / off the relays 11 and 12. The inverter 13 controls the energization of the motor 14 while the relay 11 is on by a command from a vehicle controller (not shown). The charger 19 receives electric power from a power source outside the vehicle when the vehicle is stopped, and charges the assembled battery 20 while the relay 12 is on.

The auxiliary battery 16 is, for example, a 12V lead-acid battery, and is charged by a DC / DC converter 15 that supplies electric power to the electric load 17 and is supplied with electric power from the assembled battery 20 while the relay 11 is on. NS. The voltage of the auxiliary battery 16 is not limited to 12V, and the type of the battery is not limited to the lead storage battery.

FIG. 2 is a block diagram showing a configuration example of the battery monitoring system 1 and the assembled battery 20 according to the first embodiment. In the assembled battery 20, a plurality of battery modules (corresponding to unit batteries) 21 including a secondary battery 22 connected in series or in series are further connected in series. The number of battery modules 21 included in the assembled battery 20 may be one. The battery module 21 may have a plurality of secondary batteries 22 connected in parallel. In the following, each battery module 21 is identified as a battery module_1, a battery module_2, ... Battery module_x by using module IDs 1 to x. Further, the secondary battery 22 included in each battery module 21 is identified by the cell IDs from 001 to y.

The BMU 23 includes a cell voltage detection circuit 232 that separately detects the voltage of the secondary battery 22 included in the corresponding battery module 21, a temperature detection circuit 233 that detects the temperature of the battery module 21, and a real-time clock that measures the time. It has a 234 (hereinafter, simply referred to as a clock), a wireless communication unit 237 that performs wireless communication with the battery monitoring device 100, and an MCU (Micro Control Unit) 30 that controls these.

The temperature detection circuit 233 detects the temperature of each secondary battery 22 or the battery module 21 based on a voltage signal converted from temperature to voltage by a temperature sensor (not shown) such as a thermistor included in the battery module 21. The cell voltage detection circuit 232 may detect the series voltage of a plurality of secondary batteries 22 or the voltage of the battery module 21. The clock 234 is a general-purpose clock IC that divides the oscillation frequency of 32.768 kHz by the crystal oscillator and measures the time in units of 1 second or more, but is not limited thereto.

The current detection unit 24 includes a current detection circuit 242 that detects the charge / discharge current of the assembled battery 20, that is, the charge / discharge current of the battery module 21, a clock 244 that measures the time, and wireless communication that wirelessly communicates with the battery monitoring device 100. It has a unit 247 and an MCU 40 that controls them.

The battery monitoring device 100 communicates with the clock 104 that clocks the time, the wireless communication unit 107 that wirelessly communicates with each BMU 23 and the current detection unit 24, and each unit in the vehicle according to the communication standard of CAN (Control Area Network). It has a CAN communication unit 110 and an MCU 50 that controls them. The communication unit that communicates with each unit in the vehicle is not limited to the CAN communication unit 110.

Next, the configurations of the MCUs 30, 40, and 50 will be described. FIG. 3 is a block diagram showing a configuration example of the MCU 30 included in the BMU 23. FIG. 4 is a block diagram showing a configuration example of the MCU 40 included in the current detection unit 24. FIG. 5 is a block diagram showing a configuration example of the MCU 50 included in the battery monitoring device 100.

The entire MCU 30 shown in FIG. 3 is controlled by a control unit 31 including a CPU (Central Processing Unit). The control unit 31 includes a voltage acquisition unit 32 that acquires the voltage detected by the cell voltage detection circuit 232, a temperature acquisition unit 33 that acquires the temperature detected by the temperature detection circuit 233, and a timer 35 that measures the time. , A timekeeping unit 34 (corresponding to a communication timekeeping unit) that acquires a time in units of 1 second or more from the clock 234 and clocks a time of less than 1 second using a timer 35 is connected. The control unit 31 also includes a flash memory, a non-volatile memory such as EPROM (Erasable Programmable Read Only Memory), EPROM (Electrically EPROM: registered trademark), and a DRAM (Dynamic Random Access Memory) Memory. A storage unit 36 using a rewritable memory such as the above is connected.

The control unit 31 further includes a wireless interface 37 that interfaces with the wireless communication unit 237, a clock synchronization unit 38 that synchronizes the time measured by the time measuring unit 34 with the time measured by the battery monitoring device 100, and a corresponding battery module 21. A cell voltage adjusting unit 39 that adjusts the voltage of the secondary battery 22 inside using a voltage adjusting circuit (not shown) is connected. The voltage acquisition unit 32, the temperature acquisition unit 33, the timing unit 34, the clock synchronization unit 38, and the cell voltage adjustment unit 39 are functional blocks realized by software processing executed by the control unit 31 using hardware such as an input / output interface. Is.

Moving to FIG. 4, the control unit 41 including the CPU controls the entire MCU 40. The control unit 41 uses a current acquisition unit 42 that acquires the current detected by the current detection circuit 242, a timer 45 that measures the time, and a timer 45 that acquires the time in units of 1 second or more from the clock 244. It is connected to a timekeeping unit 44 (corresponding to a communication timekeeping unit) that measures a time of less than 1 second. The control unit 41 also synchronizes the time measured by the battery monitoring device 100 with the storage unit 46 using a rewritable memory, the wireless interface 47 interfaced with the wireless communication unit 247, and the time measuring unit 44. The clock synchronization unit 48 to be used is connected. The current acquisition unit 42, the timekeeping unit 44, and the clock synchronization unit 48 are functional blocks realized by software processing executed by the control unit 41 using hardware.

Moving to FIG. 5, the control unit 51 including the CPU controls the entire MCU 50. The control unit 51 includes an aggregation unit 52 that aggregates physical quantities related to charging and discharging from each BMU 23 and a current detection unit 24, a correction information notification unit 53 that notifies information related to time correction, and a timer 55 that clocks time. , A clock unit 54 (corresponding to a monitoring time unit) that acquires a time in units of 1 second or more from the clock 104 and clocks a time of less than 1 second using a timer 55 is connected. The control unit 51 also includes a storage unit 56 using a rewritable memory, a wireless interface 57 that interfaces with the wireless communication unit 107, and a parameter estimation unit 58 that estimates the internal parameters of the secondary battery 22 or the battery module 21. A current determination unit 59 that determines the charge / discharge current for which estimation by the parameter estimation unit 58 should be prohibited is connected, and a wired interface 60 that interfaces with the CAN communication unit 110 is connected. The aggregation unit 52, the correction information notification unit 53, the timing unit 54, the parameter estimation unit 58, and the current determination unit 59 are functional blocks realized by software processing executed by the control unit 51 using hardware.

The parameter estimation unit 58 estimates the size of a resistor and a capacitor (hereinafter, these resistors and a capacitor are referred to as an internal parameter or simply a parameter) representing an equivalent circuit model of the secondary battery 22 or the battery module 21. These internal parameters can be sequentially estimated by observing the battery voltage of the secondary battery 22 or the battery module 21 and the charge / discharge current of the battery module 21. The current determination unit 59 is for prohibiting the estimation of the internal parameter when the error included in the estimation result of the internal parameter by the parameter estimation unit 58 becomes large. Details will be described later.

The software (program) executed by each of the control units 31, 41, and 51 is stored in advance in the non-volatile memory of the storage units 36, 46, and 56. Information generated by software processing executed by each of the control units 31, 41, and 51 is temporarily stored in the rewritable memory of the storage units 36, 46, and 56. A computer program in which the procedure of software processing by each of the control units 31, 41, and 51 is defined is loaded into the storage units 36, 46, 56 in advance by means (not shown), and the control units 31, 41, 51 load the computer program. You may want to do it.

In the battery monitoring system 1 described above, each BMU 23 and the current detection unit 24 correspond to a communication device. Each BMU 23 acquires the voltage of the corresponding battery module 21 or the voltage of the secondary battery 22 included in the battery module 21 at a predetermined cycle or at an aggregation cycle notified from the battery monitoring device 100, and uses the acquired battery voltage as the acquired battery voltage. The time to be measured by the time measuring unit 34 is added and transmitted to the battery monitoring device 100. Similarly, the current detection unit 24 acquires the charge / discharge current of the battery module 21 at a predetermined cycle or at the aggregation cycle notified from the battery monitoring device 100, and adds the time measured by the clock unit 44 to the acquired charge / discharge current. Is transmitted to the battery monitoring device 100. The time added by each of the BMU 23 and the current detection unit 24 does not necessarily have to be transmitted at the same time as the voltage and the charge / discharge current, and a slight deviation in the transmission time is allowed.

The transmission from each BMU 23 and the current detection unit 24 is performed in response to polling from the battery monitoring device 100, but is not limited thereto. The battery voltage, temperature, charge / discharge current, and time transmitted / received in the battery monitoring system 1 are actually transmitted / received as "data", but in the following, for example, the transmission / reception of battery voltage data is simply the battery voltage. Described as transmission / reception of.

The battery monitoring device 100 receives the battery voltage and time from each BMU 23 and also receives the charge / discharge current and time from the current detection unit 24 in a predetermined cycle or in the aggregation cycle notified to each BMU 23 and the current detection unit 24. The battery voltage and charge / discharge current are aggregated in chronological order. At that time, the battery monitoring device 100 aggregates the battery voltage and charge / discharge current in association with the time representing each aggregation cycle based on the received time, and aggregates the battery voltage and charge / discharge current (physical quantity related to charge / discharge). ; Hereafter, simply referred to as physical quantity) is sorted in the order of time representing each aggregation period. The aggregation cycle in which the battery monitoring device 100 aggregates the battery voltage and the charge / discharge current does not necessarily match the acquisition cycle in which each BMU 23 and the current detection unit 24 acquire the battery voltage and the charge / discharge current. , It is preferable that they match in order to perform efficient processing as a system.

The battery monitoring device 100 sequentially applies the battery voltage and charge / discharge current aggregated in time series to the formula of the parameter estimation method described later, and applies the battery module 21 or the secondary battery 22 included in the battery module 21. Estimate internal parameters. In order to accurately estimate this internal parameter, it is preferable to aggregate the battery voltage and charge / discharge current in a cycle shorter than 1 second. However, the clocks 234, 244 and 104 can only time in units of 1 second or more.

Therefore, in the first embodiment, the timers 35, 45, and 55 are used so that the BMU 23, the current detection unit 24, and the battery monitoring device 100 can measure the time in units of less than one second. Specifically, the timers 35, 45, 55 set the transmission frequency of 32.768 kHz generated by each of the clocks 234, 244 and 104, for example, with the time change in seconds measured by each of the clocks 234, 244 and 104 as the start point. By repeating the frequency division by 328, the time in units of 10 ms and the time in units of 100 ms are clocked.

In this method, the minimum unit of time to be clocked is actually 10.01 ms (that is, 1 / 32.768 × 328 = 10.01). In addition, since the timers 35, 45, and 55 are used to reset the time in the minimum unit of time, the minimum unit of time to be clocked is immediately before the change of the time in seconds measured by each of the clocks 234, 244, and 104. It becomes 9.01 ms (that is, 1000-10.01 × 99 = 9.01). However, if the aggregation cycle for acquiring and aggregating the battery voltage and charge / discharge current is, for example, 100 ms, it is considered that a deviation of about 1 ms when measuring the time in units of 10 ms does not matter.

The acquisition cycle and aggregation cycle may be 1 / N cycles of 1 second (N is an integer of 2 or more and 100 or less). However, it is preferable to divide 1000 by N and divide it. In this case, the acquisition cycle and aggregation cycle are 10 ms, 20 ms, 25 ms, 50 ms, 100 ms, 200 ms, 250 ms or 500 ms. When the multiple of N is 1000, the acquisition cycle can be synchronized with the time clocked by the clocks 234 and 244, and the aggregation cycle can be synchronized with the time clocked by the clock 104. Further, if the change in the time in seconds measured by the clocks 234 and 244 is the start time of the acquisition cycle and the change in the time in seconds measured by the clock 104 is the start time of the aggregation cycle, the acquisition cycle is obtained. And the phase of the aggregation period can be matched. When the start switch 18 is off, the acquisition cycle and the aggregation cycle are set to about 10 minutes, and the operation is performed intermittently.

When the aggregation cycle is, for example, 100 ms, the time added to the battery voltage and charge / discharge current acquired by the BMU 23 and the current detection unit 24, respectively, may be generally in units of 100 ms. However, if there is a non-negligible deviation between the start time of the acquisition cycle and the time when the battery voltage and charge / discharge current are actually acquired, they are added to the battery voltage and charge / discharge current acquired by the BMU 23 and the current detection unit 24, respectively. The time is preferably set to, for example, a time in units of 10 ms. When the battery voltage and charge / discharge current are aggregated, the battery monitoring device 100 treats the time added to each as a time in units of 100 ms, for example, rounded off. As a result, if the time when the battery voltage and charge / discharge current are actually acquired is delayed, the battery voltage and charge / discharge current are associated with the start time of the next aggregation cycle (same as the end time of the current aggregation cycle). Therefore, it is possible to reduce the difference between the time when the battery voltage and the charge / discharge current are acquired and the time when the battery voltage and the charge / discharge current are aggregated.

In order to estimate the above-mentioned internal parameters more accurately, it is preferable that the battery voltage and charge / discharge current acquired at the same time in each cycle are aggregated in the battery monitoring device 100. However, since the times measured by the clocks 234, 244 and 104 are generally generated by dividing the transmission frequency by the individual crystal oscillators, they deviate from each other with the passage of time. The effects of the difference in the acquisition time of the battery voltage and the charge / discharge current on estimating the internal parameters will be considered below.

FIG. 6 is a graph showing an example of waveforms of the battery voltage and charge / discharge current of the secondary battery 22. FIG. 7 is a graph showing the results of sequentially estimating the resistance parameters in the equivalent circuit model of the secondary battery 22. The horizontal axis of FIGS. 6 and 7 represents time. The vertical axis of FIG. 6 represents voltage or current, and the vertical axis of FIG. 7 represents the magnitude of resistance among the estimated parameters. In FIG. 6, the waveform of the battery voltage is shown on the upper side, and the waveforms of the charge current (plus side) and the discharge current (minus side) are shown on the lower side. Of the upper battery voltage waveforms, the solid line indicates the case where there is no delay in the acquisition time, and the broken line indicates the case where there is a certain delay in the acquisition time. This delay is indicated by the time difference of the time corresponding to the two vertical broken lines shown in FIG. Looking at the waveform of the battery voltage in correspondence with the charge current and the discharge current, it can be seen that the battery voltage fluctuates greatly up and down each time it is charged and discharged due to the voltage drop due to the internal resistance.

In FIG. 7, the resistance A estimated using the battery voltage shown by the upper solid line in FIG. 6 and the charge / discharge current shown by the lower side is shown by the solid line. Further, the resistance B estimated by using the battery voltage shown by the broken line on the upper side of FIG. 6 and the charge / discharge current shown on the lower side is shown by the broken line. As is clear from FIG. 7, if there is a discrepancy between the acquisition time of the battery voltage and the acquisition time of the charge / discharge current, the magnitude of the resistance among the internal parameters may be estimated to be smaller than the actual one. Therefore, in the first embodiment, the battery monitoring device 100 notifies each BMU 23 and the current detection unit 24 of the information related to the time correction, and each BMU 23 and the current detection unit 24 clock themselves based on this notification. Try to correct the time. As a result, the time when the battery voltage is acquired by each BMU 23 and the time when the charge / discharge current is acquired by the current detection unit 24 can be matched.

The information related to the above-mentioned time correction may be the time itself measured by the battery monitoring device 100, or may be an instruction for time correction. When notifying the time, the battery monitoring device 100 may notify the time being measured when the time in any unit measured by itself changes, but when the time measured by the clock 104 changes, the battery monitoring device 100 may notify the time. It is preferable to notify the time in units of 1 second or more. The time in units of less than 1 second is 0.00 seconds when the time measured by the clock 104 changes, so there is no need to notify. The BMU 23 and the current detection unit 24, respectively, correct the time so as to synchronize the time with their own clocks 234 and 244 according to the notified time. In this case, since the time in units of 10 ms and the time in units of 100 ms are reset, the time in units of less than 1 second is also corrected to 0.00 seconds.

For example, when the accuracy of the time measured by the clocks 234, 244 and 104 is 1 minute per month (corresponding to 23 ppm in terms of frequency accuracy), the time measured by the clock 104 is measured by the clocks 234 and 244. The time difference is 2 minutes per month, and the time shift is up to 1 ms in about 22 seconds. Therefore, it can be said that if the time is notified every 3 minutes, it is possible to prevent the accumulation of deviations of 10 ms or more. In other words, if the time is not notified for 4 minutes or more, the time measured by the clocks 234 and 244 may deviate by 10 ms (0.01 seconds) or more from the time measured by the clock 104. Even in such a case, it is possible to prevent the accumulation of time lags by instructing the time correction and correcting the advance or delay of the time measured by the clocks 234 and 244.

When notifying the time correction instruction, the battery monitoring device 100 notifies the correction instruction when the time in seconds measured by the clock 104 changes. When the instruction for time correction is notified, each BMU 23 and the current detection unit 24 detect a time lag in seconds by a time less than a second measured by the BMU 23 and the current detection unit 24. Specifically, when the time in seconds is 0.01 seconds, it is detected that the time in seconds is advanced by 0.01 seconds. If the time in seconds is 0.99 seconds, it is detected that the time in seconds is delayed by 0.01 seconds. Each BMU 23 and the current detection unit 24 make corrections to change the timekeeping speed at clocks 234 and 244, respectively, to offset the advance or lag detected in this way.

The time correction instruction may be notified in a cycle shorter than the cycle in which the advance or delay of the time detected by each BMU 23 and the current detection unit 24 increases by up to 0.01 seconds in one cycle. preferable. Therefore, when the accuracy of the time measured by the clocks 234, 244, 104 is 1 minute per month, the instruction for time correction may be notified, for example, at a cycle of 3 minutes.

The clocks 234, 244 and 104 used in the first embodiment are commercially available clock ICs, but can be corrected by changing the time counting speed by an integral multiple of ± 3 ppm. When each BMU 23 and the current detection unit 24 are notified of the time correction instruction, if it detects that the time measured by the clocks 234 and 244 is advanced by 0.01 seconds, the speed of the time measured by the clocks 234 and 244. Can be delayed by, for example, 3 ppm. Similarly, when each BMU 23 and the current detection unit 24 are notified of the time correction instruction, if they detect that the time measured by the clocks 234 and 244 is delayed by 0.01 seconds, the clocks 234 and 244 The timekeeping speed can be increased by, for example, 3 ppm.

When each BMU 23 and the current detection unit 24 are notified of the time correction instruction, if they detect that the time measured by the clocks 234 and 244 is delayed or advanced by 0.02 seconds or more, the clock 234 is used. And the timekeeping speed at 244 may be increased or decreased by, for example, 6 ppm or more. Further, in each BMU 23 and the current detection unit 24, the time measured by the clocks 234 and 244 is delayed or advanced by 0.01 second or more from the time when the instruction for correction of the previous time is notified. When it is detected, the time counting speed at the clocks 234 and 244 may be further increased or further decreased by, for example, 3 ppm. In the first embodiment, the battery monitoring device 100 notifies the instruction of time correction when the time in seconds measured by itself changes, but the clock 104 can measure the time in units of less than 1 second. Is not limited to this.

In addition to the above time correction, when it is necessary to match the time aggregated in the battery monitoring device 100 with the time measured externally, the battery monitoring device 100 synchronizes the time measured by itself with the time acquired from the outside. Let me. The time from the outside may be, for example, an absolute time acquired from a GPS receiver (not shown), a time measured by another system in the vehicle acquired via the CAN communication unit 110, or the Internet. It may be the time acquired from the connected NTP (Network Time Protocol) server.

Hereinafter, the operations of the battery monitoring device 100, each BMU 23, and the current detection unit 24 described above will be described in order using a flowchart. The case where both the acquisition cycle and the aggregation cycle are 100 ms is taken as an example, but the cycle is not limited to this cycle. First, the functions of the time measuring units 34, 44, and 54 of the battery monitoring device 100, the BMU 23, and the current detection unit 24, respectively, will be described, then the functions of each part of the battery monitoring device 100 will be described, and finally each BMU 23 and the current detection unit 24 and the current detection unit 24 will be described. The operation of the unit 24 will be described.

FIG. 8 is a flowchart showing the processing procedures of the control units 31, 41, and 51 that realize the functions of the timekeeping units 34, 44, and 54, respectively. The process of FIG. 8 is started when there is an interrupt with a 1-second cycle by each of the clocks 234, 244 and 104, or when there is an interrupt with a 10 ms cycle by each of the timers 35, 45, 55. The first time in FIG. 8 is a time in units of 1 second or more, and is stored in the storage units 36, 46, and 56. Similarly, the second time is a time in units of less than one second, and is also stored in the storage units 36, 46, 56. In the figure, j is a counter for measuring the aggregation cycle (in the case of the battery monitoring device 100) or the acquisition cycle (in the case of the BMU 23 or the current detection unit 24) in units of 10 ms. The initial value of j is an integer value representing an aggregation cycle or acquisition cycle that is an integral multiple of 10 ms, and is simply referred to as an aggregation cycle or acquisition cycle in the figure.

When the process of FIG. 8 is activated, each of the control units 31, 41, and 51 determines whether or not there is an interrupt with a 1-second cycle (S10), and if there is an interrupt (S10: YES), the clock. The time in units of 1 second or more is read from 234, 244, 104 (S11) and stored in the storage units 36, 46, 56 as the first time (S12). In this way, the step of reading out and updating the first time stored in each of the storage units 36, 46, and 56 from the clocks 234, 244 and 104 every second realizes the function of the first timekeeping unit.

Next, each of the control units 31, 41, and 51 starts measuring the time of the 10.01 ms cycle by the timers 35, 45, 55 for measuring the second time (S13), and is stored in the storage units 36, 46, 56. The second time is 0.00 seconds (S14). After that, each of the control units 31, 41, and 51 initializes j to an integer value representing the aggregation cycle or the acquisition cycle (S15), and ends the process of FIG. By this initialization, a plurality of aggregation cycles or acquisition cycles are evenly distributed in one second.

In step S10, when there is no interrupt in the 1-second cycle (S10: NO), each of the control units 31, 41, and 51 determines whether or not there is an interrupt in the 10 ms cycle (S16), and there is no interrupt. If (S16: NO), the process of FIG. 8 is terminated. On the other hand, when there is an interrupt of 10 ms (S16: YES), 0.01 second is added to the second time stored in the storage units 36, 46, 56 (S17). In this way, the step of counting up the second time stored in each of the storage units 36, 46, and 56 every 10 ms realizes the function of the second time counting unit.

Next, each of the control units 31, 41, and 51 decrements j by 1 to determine (S18) whether or not j is 0, that is, whether or not the next aggregation cycle or acquisition cycle has arrived (S19). ). When j is 0 (S19: YES), each of the control units 31, 41, and 51 initializes j to an integer value representing the aggregation cycle or the acquisition cycle (S20), and the aggregation unit 52 (in the case of the battery monitoring device 100). ) Or the process for realizing the function of the voltage acquisition unit 32 or the current acquisition unit 42 (in the case of the BMU 23 or the current detection unit 24) (S21). When the process of step S21 is completed, or when j is not 0 in step S19 (S19: NO), each of the control units 31, 41, and 51 ends the process of FIG.

FIG. 9 is a flowchart showing a processing procedure of the control unit 51 that realizes the function of the aggregation unit 52. The process of FIG. 9 is started in the aggregation cycle in step S21 of FIG. In the figure, i is a counter that counts the serial numbers of the BMU 23 and the current detection unit 24, and the initial value is 1. The number of units is the number of BMU 23 + the number of current detection units 24 (here, 1).

When the process of FIG. 9 is activated, the control unit 51 transmits a transmission instruction of the physical quantity (battery voltage or charge / discharge current) to the i-th unit (S30), and whether or not the physical quantity is received from the i-th unit. (S31). When the physical quantity is not received (S31: NO), the control unit 51 waits until it is received. In this case, the time-out may be appropriately monitored, and when the time-out occurs, the process may be moved to step S36 described later. However, in step S37, the branch determination is made so that the process of step S30 is repeated until the time-out unit is retried a predetermined number of times.

When a physical quantity is received from the i-th unit (S31: YES), the control unit 51 determines whether or not a voltage (battery voltage; the same applies hereinafter) has been received (S32). When the voltage is received (S32: YES), the control unit 51 aggregates the received voltage based on the added time in chronological order by the module ID and the cell ID described above, and the time representing each aggregation cycle. Is sorted and stored in the storage unit 56 (S33). When the received voltage is the voltage of the unit battery, it is not necessary to aggregate by cell ID. When the temperature is received together with the voltage, it is sorted in the order of time and stored in the storage unit 56 in the same manner as the voltage.

On the other hand, when the voltage is not received in step S32 (S32: NO), the control unit 51 determines whether or not a current (charge / discharge current; the same applies hereinafter) has been received (S34). When the current is received (S34: YES), the control unit 51 aggregates the received current based on the added time in chronological order so as to be common to each module ID and cell ID, and sets each aggregation cycle. It is sorted in the order of representative time and stored in the storage unit 56 (S35).

When the time added to the received physical quantity is a time in units of 10 ms, the control unit 51 rounds off the time in units of 10 ms and treats it as a time in units of 100 ms. As a result, the sorted physical quantity may be associated with a time representing the next aggregation cycle.

Here, the data structure of the physical quantity stored in the storage unit 56 will be described. FIG. 10 is an explanatory diagram schematically showing charge / discharge current, battery voltage, and temperature sorted in the order of the start time of the aggregation cycle. Each of the aggregated physical quantities is structured on one storage surface for each module ID and cell IID, and is sorted in the order of the start time of the aggregation cycle of 100 ms (an example of the time representing the aggregation cycle). For example, for cells with module ID = 1 and cell ID = 001, the latest physical quantity aggregated at 12:31:15.8 on September 1, 2018 has a charge / discharge current of -30A (discharge current). The battery voltage is 3.651 V and the temperature is 30 ° C. Each storage surface may cover at least two estimation cycles, and the number of lines in the storage surface can be limited. For example, it is preferable that each storage surface is composed of a ring buffer.

As described above, in the first embodiment, each battery module 21 is identified by a module ID from 1 to x, and each secondary battery 22 is identified by a cell ID from 001 to y. Therefore, the storage surfaces identified by the "module ID, cell ID" are "1,001", "1,002", ... "1, y", "2,001", "2,002", ... -"X, y-2", "x, y-1", "x, y" are stored in the storage unit 56 in this order. When the aggregated battery voltage is the voltage of the unit battery, the above storage surface is identified only by the module ID.

Returning to FIG. 9, when the processing of step S33 or S35 is completed, or when no current is received in step S34 (S34: NO), the control unit 51 increments i by 1 (S36) and i It is determined whether or not the number of units is +1 (S37). When i is not the number of units + 1 (S37: NO), the control unit 51 shifts the process to step S30 in order to receive the physical quantity from the next unit.

When i is the number of units + 1 (S37: YES), that is, when physical quantities are received from all the units, the control unit 51 initializes i to 1 (S38) and then parameters for each cell or unit battery. The estimation unit 58 is activated (S39). The physical quantities used in the parameter estimation unit 58 are the battery voltage and the charge / discharge current sorted by the time representing the aggregation cycle. Aggregated temperatures may be used for more accurate parameter estimation.

FIG. 11 is a flowchart showing a processing procedure of the control unit 51 that realizes the function of the correction information notification unit 53. The process of FIG. 11 is started when there is an interrupt in a 1-second cycle by the clock 104. This activation may be simultaneous with the process of FIG. 8, but it is assumed that the process of FIG. 8 has priority. M in the figure is a counter for timing the notification cycle in seconds, and the initial value is an integer value representing the notification cycle (simply referred to as the notification cycle in the figure). Further, n is a counter for measuring the correction cycle in seconds, and the initial value is an integer value representing the correction cycle (simply referred to as the correction cycle in the figure). In FIG. 11, both the time notification and the time correction instruction are broadcast-transmitted, but only one of them may be transmitted.

When the process of FIG. 11 is activated, the control unit 51 decrements m by 1 (S40) and determines whether or not m is 0 (S41). When m is 0 (S41: YES), that is, when the next notification cycle arrives, the control unit 51 initializes m to an integer value representing the notification cycle (S42), and corrects n. It is initialized to an integer value representing (S43). Next, the control unit 51 reads the first time from the time measuring unit 54 that stores the time in the storage unit 56 (S44), includes the first time in the time notification, and broadcasts the time (S45). The process of 11 is finished.

In step S41, when m is not 0 (S41: NO), the control unit 51 decrements n by 1 (S46) and determines whether or not n is 0 (S47). When n is 0 (S47: YES), that is, when the next correction cycle arrives, the control unit 51 initializes n to an integer value representing the correction cycle (S48), and then gives an instruction to correct the time. Is broadcast (S49). When the process of step S49 is completed, or when n is not 0 in step S47 (S47: NO), the control unit 51 ends the process of FIG.

FIG. 12 is a flowchart that commonly shows the processing procedures of the control units 31 and 41 that receive the signal from the battery monitoring device 100 in the BMU 23 and the current detection unit 24, respectively. Further, FIG. 13 is a flowchart showing the processing procedures of the control units 31 and 41 that realize the functions of the voltage acquisition unit 32 and the current acquisition unit 42, respectively. The process of FIG. 12 is activated when a signal is received from the battery monitoring device 100. The process of FIG. 13 is started in the acquisition cycle.

When the process of FIG. 12 is activated, each of the control units 31 and 41 determines whether or not the time notification has been received (S50). When the time notification is received (S50: YES), each of the control units 31 and 41 stores the first time in units of 1 second or more among the notified times in the storage units 36 and 46. It is stored in the time measuring units 34 and 44 (S51). The control units 31 and 41 further set the notified first time to the clocks 234 and 244, and reset the counters for less than seconds of the clocks 234 and 244 (S52). As a result, the clocks 234 and 244 and the corresponding first timekeeping unit restart the timekeeping from the notified first time.

After that, each of the control units 31 and 41 starts time counting by the timers 35 and 45 for measuring the second time (S53), and further, the second time stored in the storage units 36 and 46 is 0.00 seconds. (S54), the process of FIG. 12 is terminated. As a result, the time counting by the second timekeeping unit is restarted from 0.00 seconds.

When the time notification is not received in step S50 (S50: NO), each of the control units 31 and 41 determines whether or not the time correction instruction has been received (S55). When the instruction for time correction is received (S55: YES), each of the control units 31 and 41 stores the time in the storage units 36 and 46, and the second time in units less than one second from the timekeeping units 34 and 44. Is read (S56). It is determined whether or not the second time is 0.00 seconds (S57). When the second time is 0.00 seconds (S57: YES), each of the control units 31 and 41 ends the process of FIG. 12, assuming that the time does not need to be corrected.

When the read second time is not 0.00 seconds (S57: NO), each of the control units 31 and 41 determines whether or not the second time is smaller than 0.50 seconds (S58). This determination detects whether the second time is ahead (less than 0.50 seconds) or behind (more than 0.50 seconds) with respect to the time clocked by the battery monitoring device 100. Is for. By this determination, the advance or delay of the first time is detected.

When the read second time is smaller than 0.50 seconds (S58: YES), each of the control units 31 and 41 corrects the clocks 234 and 244 to be delayed by an integral multiple of 3 ppm according to the detected advance amount (S58: YES). S59), the process of FIG. 12 is completed. On the other hand, when the read second time is not less than 0.50 seconds (S58: NO), each of the control units 31 and 41 advances the clocks 234 and 244 by an integral multiple of 3 ppm according to the detected delay amount. The correction is performed (S60), and the process of FIG. 12 is completed. The above steps S50 to S60 correspond to the correction execution unit. In particular, steps S55 to S60 are steps for realizing the function of the clock synchronization unit.

When the time correction instruction is not received in step S55 (S55: NO), each of the control units 31 and 41 determines whether or not the physical quantity transmission instruction has been received (S61). When the physical quantity transmission instruction is received (S61: YES), each of the control units 31 and 41 reads the latest acquired physical quantity from the storage units 36 and 46 (for writing in the storage units 36 and 46, see FIG. 13 described later). ). Each of the control units 31 and 41 associates the latest read physical quantity with the module ID and cell ID to be acquired (when the physical quantity is the battery voltage), and adds the time stored in the storage units 36 and 46 (when the physical quantity is the battery voltage). (When the physical quantity is the battery voltage or the charge / discharge current) is transmitted (S62: step of realizing the function of the transmitter). If the temperature is obtained along with the voltage, include the temperature in the transmitted signal.

In step S61, when the physical quantity transmission instruction is not received (S61: NO), each of the control units 31 and 41 determines whether or not the notification of the aggregation cycle has been received (S63), and does not receive the notification (S63). : NO), the process of FIG. 12 is completed. On the other hand, when the notification of the aggregation cycle is received (S63: YES), each of the control units 31 and 41 stores the notified aggregation cycle as the acquisition cycle (S64), and ends the process of FIG.

Moving to FIG. 13, when the process of FIG. 13 is activated, each of the control units 31 and 41 acquires a physical quantity (battery voltage in the case of the control unit 31 and charge / discharge current in the case of the control unit 41) (S70). .. In the case of the control unit 31, the temperature may be acquired together with the battery voltage. The cycle for acquiring the temperature may be longer than the acquisition cycle (for example, 1 second). Step S70 is a step of realizing the functions of the voltage acquisition unit, the current acquisition unit, and the temperature acquisition unit.

Next, each of the control units 31 and 41 acquires the current time from the time counting units 34 and 44 (S71). Each of the control units 31 and 41 associates the acquired physical quantity with the module ID and cell ID to be acquired (when the physical quantity is the battery voltage), adds the acquired time (when the physical quantity is the battery voltage or the charge / discharge current). ) After storing in the storage units 36 and 46 (S72), the process of FIG. 13 is terminated.

Hereinafter, a method of estimating the internal parameters representing the equivalent circuit model of each secondary battery 22 will be described based on the battery voltage and charge / discharge current acquired and aggregated in time series as described above. FIG. 14 is an explanatory diagram showing an equivalent circuit model of the secondary battery 22 represented by a combination of a resistor and a capacitor. This equivalent circuit model is represented by a circuit in which a resistor Ra, a parallel circuit of a resistor Rb and a capacitor Cb are connected in series to a voltage source using an OCV as an electromotive force. The resistor Ra corresponds to the electrolyte resistance. The resistor Rb corresponds to the charge transfer resistance and the capacitor Cb corresponds to the electric double layer capacitance. The charge transfer resistance may be included in the resistance Ra, and the resistance Rb may correspond to the diffusion resistance.

The equivalent circuit model of the secondary battery 22 is not limited to that shown in FIG. A more complicated circuit model is assumed for the equivalent circuit model of the battery module 21 in which a plurality of secondary batteries 22 are connected in series or in parallel. For example, an nth-order (n is a natural number) Foster-type RC ladder circuit in which n parallel circuits of a resistor Rj and a capacitor Cj (j = 1, 2, ..., N) are connected in series to the resistor R0, or one ends are connected to each other. The other end of each of the n resistors Rj (j = 1, 2, ..., N) is an nth-order Cowell-type RC ladder circuit connected between n capacitors Cj connected in series, or these. It may be a combination.

Next, a method of estimating the parameters of the equivalent circuit model by the parameter estimation unit 58 will be described. It is known that the following approximate equations (1) to (4) hold for the parameters of the equivalent circuit model shown in FIG. 14 (for details, see "Battery Management Engineering" by Shuichi Adachi et al., Published by Tokyo Denki University. , 6.2.2).

uL (k) = b0 ・ i (k) + b1 ・ i (k-1) -a1 ・ uL (k-1)
+ (1 + a1) · OCV ... (1)
b0 = Ra ... (2)
b1 = TsRa / (RbCb) + Ts / Cb-Ra ... (3)
a1 = Ts / (RbCb) -1 ... (4)
However,
uL: Battery voltage i: Charge / discharge current Ts: Estimated cycle (k is, for example, an estimation step)
OCV: Open circuit voltage

When the parameters Ra, Rb and Cb are back-calculated from the above equations (2) to (4), the following equations (5) to (7) are established.

Ra = b0 ... (5)
Rb = (b1-a1b0) / (1 + a1) ... (6)
Cb = Ts / (b1-a1b0) ... (7)

In the present embodiment, the successive least squares method is applied to the equation (1) to determine the coefficients b0, b1 and a1, and the determined coefficients are substituted into the equations (5) to (7) to substitute the parameters Ra, Rb and Cb. To estimate. Although Ts does not necessarily have to coincide with the aggregation cycle, it will be described here assuming that Ts is equal to the acquisition cycle and the aggregation cycle. It is assumed that the OCV (Open Circuit Voltage) is constant while each parameter is estimated. The estimated parameters may be corrected according to the temperature aggregated with the battery voltage.

By the way, in the equation (1), there are four unknowns (a1, b0, b1 and OCV), and at least four equations are required to obtain these values. However, for the charge / discharge current i, when i (k) = i (k-1) = 0, the values of the terms related to b0 and b1 become zero, and the equations (5) to (7) are satisfied. It disappears. Further, when i (k) = i (k-1) = constant, the change in OCV due to the flow of the constant current only appears in u (k), and the change in u (k) becomes extremely small. Therefore, it is difficult to estimate the parameters accurately.

Therefore, in the first embodiment, when it is highly probable that the parameter estimation unit 58 cannot properly estimate the parameters from the determination result of the current determination unit 59 shown in FIG. 5, the parameter estimation unit 58 prohibits the parameter estimation. do. That is, when the parameter estimation is not prohibited by the current determination unit 59, the parameter estimation unit 58 is based on the battery voltage uL and the charge / discharge current i aggregated in the storage unit 56 in time series, and the parameter Ra is as described above. , Rb, Cb are output.

The current determination unit 59 estimates the parameters by the parameter estimation unit 58 when the aggregated charge / discharge current i is smaller than the first threshold value and when the amount of change in the aggregated charge / discharge current i is smaller than the second threshold value. proclaim. When the parameter estimation is prohibited by the current determination unit 59, the parameter estimation unit 58 continues to output the previously estimated parameter without updating it.

Hereinafter, the operation of the battery monitoring device 100 described above will be described with reference to a flowchart. FIG. 15 is a flowchart showing a processing procedure of the control unit 51 that sequentially estimates parameters by the battery monitoring device 100. FIG. 16 is a flowchart showing a processing procedure of the control unit 51 related to the current determination subroutine. The current determination subroutine realizes the function of the current determination unit. The process shown in FIG. 15 is the main routine and is started in step S39 shown in FIG. The calculation result in each step is appropriately stored in the storage unit 56. In FIG. 9, the charge / discharge current is simply referred to as a current.

When the main routine of FIG. 15 is activated, the control unit 51 reads the battery voltage uL (k) in the current aggregation cycle from the storage unit 56 (S81) and also reads the charge / discharge current i (k) (S82). .. Next, the control unit 51 calls a subroutine related to the current determination (S83). When Ts does not match the acquisition cycle and the aggregation cycle, the battery voltage and charge / discharge current at the time corresponding to the estimation step k or the time closest to the estimation step k are read from the storage unit 56, and each is UL (k). And i (k).

Moving to FIG. 16, when the subroutine related to the current determination is called, the control unit 51 determines whether | i (k) | is smaller than the first threshold value (S91), and is smaller than the first threshold value. (S91: YES), memorizing that the estimation of the parameter is prohibited (S92), and returning to the main routine. The first threshold value may be a fixed value obtained by experiments or simulations, or may be a variable value changed according to running conditions.

When | i (k) | is not smaller than the first threshold value (S91: NO), the control unit 51 determines the current i (k-1) previously read from the storage unit 56 and the current i (k) read this time. | Δi |, which is the difference between the two, is calculated (S93). Next, the control unit 51 determines whether or not the calculated | Δi | is smaller than the second threshold value (S94), and if it is smaller than the second threshold value (S94: YES), shifts the process to step S92. As a result, it is memorized that the estimation of the parameter is prohibited.

When | Δi | is not smaller than the second threshold value (S94: NO), the control unit 51 remembers that the estimation of the parameter is not prohibited (S95) and returns to the main routine.

Returning to FIG. 15, when returning from the subroutine related to the current determination, the control unit 51 determines whether or not it is stored that the parameter estimation is prohibited, that is, whether or not the parameter estimation is prohibited. (S84), if prohibited (S84: YES), the execution of the main routine of FIG. 15 ends without estimating the parameters. As a result, the control unit 51 continues to output the previously estimated parameter without updating it.

When the parameter estimation is not prohibited (S84: NO), the control unit 51 uses the sequential least squares method and uses the parameters Ra (k), Rb (k), and Cb (7) according to the equations (1) to (7). k) is estimated (S85). Next, the control unit 51 changes the estimated values of the output parameters from Ra (k-1), Rb (k-1), and Cb (k-1) to Ra (k), Rb (k), and Cb (k). Update (S86) to end the execution of the main routine.

Next, an example of the parameters estimated by the processing shown in FIGS. 15 and 16 will be described. FIG. 17 is a graph showing waveforms of the battery voltage and charge / discharge current of the secondary battery 22 for which parameters are estimated. The upper part of the figure shows the waveform of the battery voltage, and the lower part shows the waveform of the charge current (plus side) and the discharge current (minus side). The horizontal axis of FIG. 17 represents time, and the vertical axis represents voltage in the upper row and current in the lower row. Focusing especially on the charge / discharge current in the lower stage, the magnitude of the current changes significantly to plus and minus at the point where the charge / discharge is switched, and the period in which the magnitude of the current is close to 0 (zero) continues for a relatively long time. You can see that it is doing. At such points and periods, it is difficult to accurately estimate the parameters as described above.

FIG. 18 is a graph showing the results of sequentially estimating the parameters of the equivalent circuit model of the secondary battery 22. The estimation results of the parameters Ra, Rb and Cb are shown by solid lines in the upper, middle and lower rows of the figure, respectively. The broken line in the figure indicates the magnitude of each parameter actually measured by the so-called AC impedance method. In FIG. 18, the horizontal axis represents time and the vertical axis represents resistance or capacitance. According to FIG. 18, it can be read that each of the parameters Ra, Rb and Cb converges toward the actually measured value even though there is a point and a period during which the charge / discharge current shown in FIG. 17 becomes 0.

As described above, according to the first embodiment, each BMU 23 and the current detection unit 24 charge / discharge the secondary battery 22 or the battery module 21 from the battery module 21 including one or a plurality of series or parallel secondary batteries 22. The physical quantity according to the above is periodically acquired, and the battery monitoring device 100 monitors the charge / discharge of the assembled battery 20 in which a plurality of battery modules 21 are connected in series. When the battery monitoring device 100 notifies the information related to the time correction based on the time measured by itself, each BMU 23 and the current detection unit 24 correct the time measured by themselves based on the notified information. Each BMU 23 and the current detection unit 24 periodically acquire a physical quantity related to charging / discharging from the battery module 21, add a time measured by itself, and transmit the physical quantity to the battery monitoring device 100. The battery monitoring device 100 periodically aggregates the received physical quantity based on the time of reception. As a result, the time referred to when the battery monitoring device 100 is aggregated is the time corrected by the notification from the battery monitoring device 100. Therefore, the physical quantity related to charging / discharging acquired from the secondary battery 22 or the battery module 21 included in the assembled battery 20 can be associated with the common time of the system and aggregated in the battery monitoring device 100.

Further, according to the first embodiment, when the battery monitoring device 100 notifies each BMU 23 and the current detection unit 24 of the time when the time in seconds measured by itself changes, each BMU 23 and the current detection unit 24 According to the notified time, the time measured by itself is rounded to the time in seconds and corrected. Therefore, the time measured by the battery monitoring device 100, each BMU 23, and the current detection unit 24 can be synchronized.

Further, according to the first embodiment, when the battery monitoring device 100 notifies each BMU 23 and the current detection unit 24 of the time correction instruction when the time in seconds measured by itself changes, each BMU 23 and the current detection unit 24 detects a time lag in a unit smaller than the second unit timed by itself when notified of the instruction, and corrects the lag of the clocks 234 and 244. Therefore, in order to correct the advance or delay of the clocks 234 and 244 based on the time difference detected by each BMU 23 and the current detection unit 24, the time measured by the battery monitoring device 100 and each BMU 23 and the current detection unit 24 is set. It can be converged to match.

Further, according to the first embodiment, the time measured by the battery monitoring device 100 is synchronized with the time acquired from the outside. Therefore, the time measured by the battery monitoring device 100 can be made to follow the time from the outside with high accuracy.

Further, according to the first embodiment, the battery monitoring device 100 obtains the physical quantity related to the charge / discharge acquired by each BMU 23 and the current detection unit 24 in the acquisition cycle, and has the same length as the acquisition cycle based on the time added to the physical quantity. In the summarization cycle, the summation is performed in association with the start time of each summarization cycle. Therefore, acquisition and aggregation of physical quantities related to charge / discharge can be performed in a one-to-one manner, and the aggregation results can be sorted in the order of the start time of each aggregation cycle.

Further, according to the first embodiment, the battery monitoring device 100 notifies each BMU 23 and the current detection unit 24 of the aggregation cycle, and each BMU 23 and the current detection unit 24 are filled with an acquisition cycle having the same length as the notified aggregation cycle. Acquire the physical quantity related to the discharge. Therefore, the acquisition cycle of the physical quantity related to charge / discharge can be changed from the battery monitoring device 100.

Further, according to the first embodiment, among the times measured by the time units 34, 44, and 54, the time in the unit of 1 second or more is timed by the first time unit, and the time in the unit of less than 1 second is the second. The timekeeping part synchronizes with the first timekeeping part. When the battery monitoring device 100 notifies each BMU 23 and the current detection unit 24 of information relating to the time correction in units of 1 second or more, each BMU 23 and the current detection unit 24 correct the time measured by the first time unit. As a result, a general-purpose real-time clock that clocks the time in units of 1 second or more can be used for the first clock, and when the first clock is corrected by each BMU 23 and the current detection unit 24, the second clock is used. It can be corrected in synchronization with the first timing section.

Further, according to the first embodiment, the aggregation cycle is a cycle in which the time corresponding to the N cycle is exactly 1 second, and one cycle of the N cycle is 1 second measured by the first timekeeping unit. The turning point is the start time. Therefore, the physical quantities related to charging / discharging can be aggregated in a cycle shorter than 1 second. Further, when the first time portion of each BMU 23 and the current detection unit 24 is corrected, the phases of the acquisition cycle and the aggregation cycle can be matched in the battery monitoring system 1.

Further, according to the first embodiment, each BMU 23 and the current detection unit 24 add a time in units of 10 ms, which is smaller than 100 ms, when the physical quantity related to charge / discharge is acquired in a cycle of, for example, 100 ms. The battery monitoring device 100 aggregates the physical quantities related to charge / discharge acquired by each BMU 23 and the current detection unit 24 in association with the start time or end time of each aggregation cycle based on the time added to the physical quantity. .. Therefore, if the time to actually acquire the physical quantity related to charge / discharge is delayed, the physical quantity related to charge / discharge can be aggregated in association with the start time of the next aggregation cycle.

Further, according to the first embodiment, the minimum square method is applied by sequentially applying the time-series aggregated voltage and charge / discharge current to the equation (1) expressing the relationship between the voltage and the charge / discharge current of the secondary battery 22. By using, the coefficients b0, b1 and a1 of the equation (1) are determined, and the parameters Ra, Rb and Cb are estimated based on the determined coefficients. Therefore, the internal parameters of the secondary battery 22 can be estimated in time series.

Further, according to the first embodiment, if the absolute value of the charge / discharge current is smaller than the first threshold value while estimating the parameters of the secondary battery 22, the parameters are not estimated. Therefore, if the parameter estimation error is inevitably large, the parameter update can be deferred.

Further, according to the first embodiment, if the difference between the charge / discharge current aggregated in the current aggregation cycle and the charge / discharge current aggregated in the previous aggregation cycle is smaller than the second threshold value, the parameter is estimated. No. Therefore, if the parameter estimation error is inevitably large, the parameter update can be deferred.

(Embodiment 2)
In the first embodiment, the battery monitoring device 100 and the current detection unit 24 are separated, whereas in the second embodiment, the functions of the current detection unit 24 are integrated in the battery monitoring device 100b. be. Further, in the first embodiment, the battery monitoring device 100 polls each BMU 23 and the current detection unit 24 to transmit the battery voltage and the charge / discharge current, whereas in the second embodiment, each BMU 23 acquires the battery voltage. In that case, there is a difference in that the battery voltage is transmitted autonomously.

FIG. 19 is a block diagram showing a configuration example of the battery monitoring system 1b and the assembled battery 20 according to the second embodiment. FIG. 20 is a block diagram showing a configuration example of the MCU 50b included in the battery monitoring device 100b. In the battery monitoring system 1b, as compared with the battery monitoring system 1 shown in FIG. 2 of the first embodiment, the battery monitoring device 100 is replaced with the battery monitoring device 100b, and the current detection unit 24 is reduced.

The battery monitoring device 100b includes a clock 104, a wireless communication unit 107, a CAN communication unit 110, a current detection circuit 242, and an MCU 50b that controls them. That is, in the battery monitoring device 100b, the MCU 50 is replaced with the MCU 50b and the current detection circuit 242 is added as compared with the battery monitoring device 100 shown in FIG. 2 of the first embodiment.

The MCU 50b shown in FIG. 20 has a control unit 51, an aggregation unit 52b, a correction information notification unit 53, a timing unit 54, a timer 55, a storage unit 56, a wireless interface 57, a parameter estimation unit 58, and a current. The determination unit 59, the wired interface 60, and the current acquisition unit 42b are connected. That is, in the MCU 50b, the aggregation unit 52 is replaced with the aggregation unit 52b, and the current acquisition unit 42b is added, as compared with the MCU 50 shown in FIG. 5 of the first embodiment. Other parts corresponding to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the battery monitoring system 1b described above, each BMU 23 corresponds to a communication device. The operation of each BMU 23 is the same as that of the first embodiment, except that when the acquired battery voltage is transmitted with the time added, the BMU 23 is transmitted without polling. Similar to the current detection unit 24 according to the first embodiment, the battery monitoring device 100b acquires the charge / discharge current of the battery module 21 and aggregates the charge / discharge current of the battery module 21 together with the battery voltage received from each BMU 23 in chronological order.

Hereinafter, the operations of the battery monitoring device 100b and each BMU 23 will be described in order using a flowchart. FIG. 21 is a flowchart showing a processing procedure of the control unit 51 that realizes the function of the current acquisition unit 42b and a part of the functions of the aggregation unit 52b. FIG. 22 is a flowchart showing a processing procedure of the control unit 51 that realizes some other functions of the aggregation unit 52b. Further, FIG. 23 is a flowchart showing a processing procedure of the control unit 31 that realizes the function of the voltage acquisition unit 32.

The flowchart shown in FIG. 21 includes a step of aggregating the charge / discharge current and several steps until the parameter estimation unit 58 is started, as compared with the flowchart of the current acquisition unit 42 shown in FIG. 13 of the first embodiment. Has been added. The flowchart shown in FIG. 22 is a few steps until the step of aggregating the charge / discharge current is deleted and the parameter estimation unit 58 is started, as compared with the flowchart of the aggregation unit 52 shown in FIG. 9 of the first embodiment. Step has been deleted. The flowchart shown in FIG. 23 is different from the flowchart related to the voltage acquisition unit 32 shown in FIG. 13 of the first embodiment in a step of autonomously transmitting the acquired voltage.

The process of FIG. 21 is started in the acquisition cycle (same as the aggregation cycle). The process of FIG. 22 is activated when a signal is received from each BMU 23. The process of FIG. 23 is started in the acquisition cycle. When the process of FIG. 21 is activated, the control unit 51 acquires the charge / discharge current (S100). Next, the control unit 51 acquires the current time from the time measuring unit 54 (S101), and aggregates the acquired charge / discharge currents based on the acquired time in chronological order so as to be common to each module ID and cell ID. It is sorted in the order of time representing each aggregation cycle and stored in the storage unit 56 (S102).

After that, the control unit 51 determines whether or not all the battery voltages have been received from all the BMUs 23 in the current aggregation cycle (S103), and if received (S103: YES), shifts the process to step S106 described later. .. When not all battery voltages have been received (S103: NO), the control unit 51 acquires the current time from the timekeeping unit 54 (S104), and whether or not the battery voltage aggregation in the current aggregation cycle has timed out. Is determined (S105).

If the time-out has not occurred (S105: NO), the control unit 51 shifts the process to step S103. On the other hand, when the time-out occurs (S105: YES), the control unit 51 activates the parameter estimation unit 58 for each cell or unit battery (S106), and then ends the process of FIG. 21.

When the process of FIG. 22 is activated, the control unit 51 determines whether or not a voltage has been received from the BMU 23 (S110). When the voltage is received (S110: YES), the control unit 51 aggregates the received voltage by module ID and cell ID in chronological order, sorts them in the order of the time representing each aggregation cycle, and stores them in the storage unit 56. Store (S111). After that, the control unit 51 ends the process of FIG. 22. When the voltage is not received in step S110 (S110: NO), the control unit 51 ends the process of FIG. 22 as it is.

When the process of FIG. 23 is activated, the control unit 31 acquires the battery voltage (S120). Next, the control unit 31 acquires the current time from the timekeeping unit 34 (S121), and waits for a different time for each BMU 23 (S122). This standby is to prevent the transmissions from the BMUs 23 from colliding with each other. The retry sequence may be executed as appropriate. After the standby, the control unit 31 associates the acquired voltage with the module ID and the cell ID to be acquired, adds the acquired time, and transmits the voltage (S123: step of realizing the function of the transmission unit). End the process.

As described above, according to the second embodiment, each BMU 23 periodically acquires the battery voltage of the secondary battery 22 or the battery module 21 from the battery module 21 including one or more secondary batteries 22, and the battery. The monitoring device 100b monitors the charge / discharge of the assembled battery 20 in which a plurality of battery modules 21 are connected in series. When the battery monitoring device 100b notifies the information related to the time correction based on the time measured by itself, each BMU 23 corrects the time measured by itself based on the notified information. Each BMU 23 periodically acquires the battery voltage from the battery module 21, adds a time to be clocked by itself, and transmits the battery voltage to the battery monitoring device 100b. The battery monitoring device 100b periodically aggregates the received battery voltage based on the time when it is received, and also aggregates the charge / discharge current acquired from the battery module 21 by itself. As a result, the time referred to when aggregating to the battery monitoring device 100b is the time corrected by the notification from the battery monitoring device 100b. Therefore, the physical quantity related to charging / discharging acquired from the secondary battery 22 or the battery module 21 included in the assembled battery 20 can be associated with the common time of the system and aggregated in the battery monitoring device 100b.

Further, according to the second embodiment, since the battery monitoring device 100b also serves as the current detection unit 24, the number of communication devices can be reduced.

1, 1b Battery monitoring system 11, 12 Relay 13 Inverter 14 Motor 15 DC / DC converter 16 Auxiliary battery 17 Electric load 18 Start switch 19 Charger 20 sets Battery 21 Battery module 22 Secondary battery 23 BMU
24 Current detection unit 30, 40, 50, 50b MCU
31, 41, 51 Control unit 32 Voltage acquisition unit 33 Temperature acquisition unit 34, 44, 54 Timing unit 35, 45, 55 Timer 36, 46, 56 Storage unit 37, 47, 57 Wireless interface 38, 48 Clock synchronization unit 39 cells Voltage adjustment unit 42, 42b Current acquisition unit 52, 52b Aggregation unit 53 Correction information notification unit 58 Parameter estimation unit 59 Current determination unit 60 Wired interface 100, 100b Battery monitoring device 104, 234, 244 Clock 107, 237, 247 Wireless communication unit 110 CAN communication unit 200 Secondary battery unit 232 Cell voltage detection circuit 233 Temperature detection circuit 240 Current sensor 242 Current detection circuit

Claims (14)

A battery monitoring system including a plurality of communication devices for acquiring physical quantities related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and a battery monitoring device for monitoring the charging / discharging of the plurality of unit batteries. hand,
The communication device is
Communication timekeeping section that measures the time and
A correction execution unit that corrects the time measured by the communication clock unit based on the correction information notified from the battery monitoring device, and a correction execution unit.
It is provided with a transmission unit that adds a time measured by the communication clock unit to the physical quantity acquired from the unit battery and transmits the time to the battery monitoring device.
The battery monitoring device is
A monitoring timekeeping unit that measures the time,
A correction information notification unit that notifies the communication device of information related to the correction of the time measured by the communication time unit based on the time measured by the monitoring time unit.
A battery monitoring system including an aggregation unit that aggregates the physical quantity received from the communication device based on a time added to the physical quantity. The information related to the correction of the time is the time notified by the correction information notification unit when the time of a predetermined unit changes among the times measured by the monitoring time unit.
The battery monitoring system according to claim 1, wherein the correction execution unit corrects the time measured by the communication timekeeping unit to the notified time. The information related to the time correction is an instruction for time correction notified by the correction information notification unit when the time of a predetermined unit measured by the monitoring time unit changes.
When notified of the instruction, the correction execution unit detects a time lag of less than the predetermined unit timed by the communication timekeeping unit, and corrects the delay or advance of the time measured by the communication timekeeping unit. Item 1. The battery monitoring system according to item 1. The battery monitoring system according to any one of claims 1 to 3, wherein the battery monitoring device synchronizes the time measured by the monitoring time unit with a time acquired from the outside. The aggregation cycle in which the aggregation unit aggregates the physical quantity is the same as the acquisition cycle in which the communication device acquires the physical quantity.
The item according to any one of claims 1 to 4, wherein the aggregation unit aggregates the physical quantity in association with a time representing each of the aggregation cycles based on the time added to the physical quantity. Battery monitoring system. The battery monitoring device is designed to notify the communication device of a cycle for aggregating the physical quantity.
The battery monitoring system according to claim 5, wherein the communication device acquires the physical quantity at a cycle notified from the battery monitoring device. The communication time unit includes a first time unit that measures the time in units of 1 second or more, and a second time unit that measures the time in units of less than 1 second in synchronization with the time measured by the first time unit. Including
The correction information notification unit notifies information related to the correction of the time when the time in units of 1 second or more measured by the monitoring timekeeping unit changes.
The battery monitoring system according to claim 5 or 6, wherein the correction execution unit corrects the time measured by the first timekeeping unit. The acquisition cycle is a cycle of 1 / N seconds (N is an integer of 2 or more) measured based on the time measured by the second time section, and the time measured by the first time section changes. The battery monitoring system according to claim 7, which includes a cycle having the same time as the time as the start time. The time added by the communication device is a time in a unit smaller than the unit of time corresponding to the acquisition cycle.
Any of claims 5 to 8, wherein the aggregation unit aggregates the physical quantity in association with either the start time or the end time of each of the aggregation cycles based on the time added to the physical quantity. The battery monitoring system according to item 1. The physical quantity includes the voltage of the secondary battery or the unit battery and the charge / discharge current of the unit battery.
The battery monitoring device sets parameters of the equivalent circuit model of the secondary battery or the unit battery based on the voltage of the secondary battery or the unit battery and the charge / discharge current of the unit battery aggregated in time series. The battery monitoring system according to any one of claims 5 to 9, further comprising an estimation unit for estimating. 10. The battery monitoring device includes an estimation prohibition unit that prohibits estimation of the parameters when the absolute value of the charge / discharge current of the secondary battery or the unit battery aggregated in time series is smaller than the first threshold value. Battery monitoring system described in. 10. The battery monitoring device includes an estimation prohibition unit that prohibits estimation of the parameter when the difference between the charge / discharge currents of the secondary battery or the unit battery aggregated in adjacent cycles is smaller than the second threshold value. Battery monitoring system described in. The communication device acquires the voltage of the unit battery or the secondary battery contained in the unit battery, and obtains the voltage.
The battery monitoring system according to any one of claims 10 to 12, wherein the battery monitoring device acquires the charge / discharge current of the unit battery and aggregates it in itself. In a battery monitoring system including a plurality of communication devices for acquiring physical quantities related to charging / discharging from a plurality of unit batteries including one or a plurality of secondary batteries, and a battery monitoring device for monitoring the charging / discharging of the plurality of unit batteries. A method of consolidating the physical quantity in the battery monitoring device.
In the communication device
A step of correcting the time measured by the own communication clock based on the correction information notified from the battery monitoring device, and
The step includes a step of adding a time measured by the communication timekeeping unit to the physical quantity acquired from the unit battery and transmitting the time to the battery monitoring device.
With the battery monitoring device
A step of notifying the communication device of information related to the correction of the time measured by the communication time unit based on the time measured by the own monitoring time unit.
A physical quantity aggregation method including a step of aggregating the physical quantity received from the communication device based on a time added to the physical quantity.

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