JP7254482B2 - Rechargeable battery status detection device and rechargeable battery status detection method - Google Patents

Description

The present invention relates to a rechargeable battery state detection device and a rechargeable battery state detection method.

In Patent Document 1, a rechargeable battery is subjected to multiple pulse discharges in rest periods between charging steps, and after different pulse discharges (for example, after the first pulse discharge and after the second pulse discharge). are compared, and if the difference exceeds a threshold value, a technology is disclosed that controls the charging conditions.

JP-A-11-509078

However, in the technology disclosed in Patent Document 1, the voltage behavior after discharge varies depending on the size, type (normal liquid type, idling stop car, etc.) and manufacturer of the rechargeable battery, so a threshold value is set for each rechargeable battery. There is a need.

More specific description will be given. FIG. 27 shows the measurement results of the voltage after the first pulse discharge (arrows) and the voltage after the fourth pulse discharge (arrows) at SOCs of 100% and 80% for rechargeable batteries of size category LN2. In the rechargeable battery of size category LN2, the differential value after the pulse is 0.011 V when the SOC is 100%, as indicated by the solid curve, and the differential value after the pulse is 0.003 V when the SOC is 80%, as indicated by the dashed curve. is.

FIG. 28 shows the measurement results of the voltage after the first pulse discharge (arrows) and the voltage after the fourth pulse discharge (arrows) at SOCs of 100% and 80% for rechargeable batteries of size category LN5. For the rechargeable battery of size category LN5, the difference value after the pulse is 0.006 V when the SOC is 100%, as indicated by the solid curve, and the difference value after the pulse is 0.001 V when the SOC is 80%, as indicated by the dashed curve. is.

Therefore, in order to distinguish between 80% and 100% SOC, the threshold is set to 0.009 V for rechargeable batteries of size category LN2, and the threshold is set to 0.009 V for rechargeable batteries of size category LN5. Should be set to 0.005V. That is, there is a problem that it is necessary to change the setting of the threshold according to the size of the rechargeable battery. Although not shown in FIGS. 27 and 28, it is necessary to change the setting of the threshold depending on the type and manufacturer of the rechargeable battery.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and is a rechargeable battery state detection device capable of accurately estimating the state of a rechargeable battery regardless of the size, type, etc. of the rechargeable battery. and to provide a rechargeable battery status detection method.

In order to solve the above-described problems, the present invention provides a rechargeable battery state detection device for detecting the state of a rechargeable battery, wherein a control signal is supplied to a discharge circuit for discharging the rechargeable battery, thereby detecting the state of the rechargeable battery. receiving means for receiving a voltage signal from a voltage sensor that detects the terminal voltage of the rechargeable battery and a current signal from a current sensor that detects the charging and discharging current of the rechargeable battery; Referencing the voltage signal received by the receiving means, detecting a variation between a voltage before pulse discharging of the rechargeable battery by the discharging circuit and a voltage of the rechargeable battery during or after discharging. detecting means; determining means for referencing said current signal received by said receiving means to determine whether said rechargeable battery has been charged or discharged between a first point in time and a second subsequent point in time; The rechargeable battery based on the first variation value detected by the detection means at the first time point, the second variation value detected by the detection means at the second time point, and the determination result of the determination means. and an output means for outputting an estimation result of the estimation means.
According to such a configuration, it is possible to accurately estimate the state of the rechargeable battery regardless of the size, type, etc. of the rechargeable battery.

Further, in the present invention, the detecting means detects a difference value between a voltage before pulse discharging by the discharging circuit and a voltage of the rechargeable battery during or after discharging, and the estimating means detects the second determination results of charge/discharge of the rechargeable battery between the first time point and the second time point; a first difference value and a second difference value respectively detected by the detection means at the first time point and the second time point; and estimating the state of charge of the rechargeable battery based on.
According to such a configuration, the state of charge of the rechargeable battery can be easily estimated using the difference value.

Further, according to the present invention, the estimating means detects the above detected by the detecting means when the determining means determines that the rechargeable battery is charged between the first time point and the second time point. the detection when the second difference value is smaller than the first difference value, or when the determination means determines that the rechargeable battery is discharged between the first time point and the second time point; It is characterized in that when the second difference value detected by means is larger than the first difference value, it is determined that the rechargeable battery is in a nearly fully charged state.
With such a configuration, it is possible to reliably know whether or not the rechargeable battery is in a nearly fully charged state based on the difference value and the charging/discharging determination result.

Also, in the present invention, the detecting means detects the internal resistance value calculated based on the voltage and current before pulse discharging by the discharging circuit and the voltage and current of the rechargeable battery during or after discharging. , the estimating means determines the charging/discharging determination result of the rechargeable battery between the first time point and the second time point, and the first internal state detected by the detecting means at the first time point and the second time point. The state of charge of the rechargeable battery is estimated based on the resistance value and the second internal resistance value.
With such a configuration, the state of charge of the rechargeable battery can be easily estimated based on the internal resistance value.

Further, according to the present invention, the estimating means detects the above detected by the detecting means when the determining means determines that the rechargeable battery is charged between the first time point and the second time point. When the second internal resistance value is greater than the first internal resistance value, or when the determination means determines that the rechargeable battery is discharged between the first time point and the second time point When the second internal resistance value detected by the detecting means is smaller than the first internal resistance value, it is determined that the rechargeable battery is in a nearly fully charged state.
With such a configuration, it is possible to reliably know whether or not the rechargeable battery is in a nearly fully charged state based on the internal resistance value and the charging/discharging determination result.

Further, according to the present invention, the control means causes the discharge circuit to perform pulse discharge a plurality of times,
The detection means is characterized in that it detects a variation value of the voltage of the rechargeable battery before the plurality of pulse discharges and during or after the second and subsequent pulse discharges.
According to such a configuration, the state of charge of the rechargeable battery can be known more accurately based on the detection results obtained by pulse discharge a plurality of times.

The present invention also provides a rechargeable battery state detection method for detecting a state of a rechargeable battery, in which a control step of supplying a control signal to a discharge circuit for discharging the rechargeable battery to pulse-discharge the rechargeable battery. a receiving step of receiving a voltage signal from a voltage sensor that detects a terminal voltage of the rechargeable battery and a current signal from a current sensor that detects a charging/discharging current of the rechargeable battery; a detection step of referring to the voltage signal received and detecting a variation value between a voltage before the rechargeable battery is pulse-discharged by the discharge circuit and a voltage of the rechargeable battery during or after discharging; determining whether the rechargeable battery has been charged or discharged between a first time point and a second time point thereafter, with reference to the current signal received in the step; estimating the state of charge of the rechargeable battery based on the first variation value detected in the step, the second variation value detected in the detection step at the second time point, and the determination result of the determination step; The method is characterized by comprising an estimation step and an output step of outputting an estimation result of the estimation step.
According to such a method, it is possible to accurately estimate the state of the rechargeable battery regardless of the size, type, etc. of the rechargeable battery.

According to the present invention, it is possible to provide a rechargeable battery state detecting device and a rechargeable battery state detecting method capable of accurately estimating the state of a rechargeable battery regardless of the size, type, etc. of the rechargeable battery. becomes.

1 is a diagram showing a configuration example of a rechargeable battery state detection device according to a first embodiment of the present invention; FIG. 2 is a block diagram showing a detailed configuration example of a control unit in FIG. 1; FIG. FIG. 2 is a diagram showing a time waveform of a current flowing by the discharging circuit shown in FIG. 1; FIG. 2 is a diagram showing a time waveform of voltage by the discharging circuit shown in FIG. 1; 5 is a diagram showing the relationship between SOC and voltage change based on the measurements shown in FIG. 4; FIG. 4 is a flow chart for explaining an example of the operation of the first exemplary embodiment of the present invention; 7 is a diagram for explaining the timing at which the flowchart shown in FIG. 6 is executed; FIG. It is a figure for demonstrating the operation|movement of 2nd Embodiment of this invention. FIG. 9 is a diagram showing the relationship between SOC and voltage change based on the measurements shown in FIG. 8; It is a figure for demonstrating the operation|movement of 3rd Embodiment of this invention. FIG. 11 is a diagram showing the relationship between SOC and internal resistance based on the measurements shown in FIG. 10; It is a figure for demonstrating the operation|movement of 4th Embodiment of this invention. 13 is a diagram showing the relationship between SOC and voltage change based on the measurement shown in FIG. 12; FIG. It is a figure for demonstrating the operation|movement of 5th Embodiment of this invention. 15 is a diagram showing the relationship between SOC and voltage change based on the measurement shown in FIG. 14; FIG. It is a figure for demonstrating the operation|movement of 6th Embodiment of this invention. FIG. 17 is a diagram showing the relationship between SOC and internal resistance based on the measurements shown in FIG. 16; FIG. 3 is a diagram for explaining charge/discharge cycles when actually measuring a rechargeable battery; FIG. 10 is a diagram showing waveforms obtained by actually measuring a rechargeable battery of size category LN2; FIG. 20 is a diagram showing the relationship between states and voltage changes based on the actual measurement results shown in FIG. 19; FIG. 10 is a diagram showing waveforms obtained by actually measuring a rechargeable battery of size class LN5; FIG. 22 is a diagram showing the relationship between states and voltage changes based on the actual measurement results shown in FIG. 21; FIG. 10 is a diagram showing waveforms obtained by actually measuring a rechargeable battery of battery type M-42; FIG. 24 is a diagram showing the relationship between states and voltage changes based on the actual measurement results shown in FIG. 23; FIG. 10 is a diagram showing waveforms obtained by actually measuring a rechargeable battery of battery type M-42; 26 is a diagram showing the relationship between the state and the internal resistance based on the actual measurement results shown in FIG. 25; FIG. FIG. 2 is a diagram showing measurement results of a rechargeable battery of size category L2 according to the prior art; FIG. 3 is a diagram showing measurement results of a rechargeable battery of size category L5 according to the prior art;

Next, embodiments of the present invention will be described.

(A) Description of Configuration of First Embodiment of the Invention FIG. 1 is a diagram showing a power supply system of a vehicle having a rechargeable battery state detection device according to a first embodiment of the invention. In this figure, a rechargeable battery state detection device 1 has a control unit 10 as a main component, a voltage sensor 11, a current sensor 12, a temperature sensor 13, and a discharge circuit 15 are connected to the outside, and a rechargeable battery 14 to detect the state of Note that the control unit 10, the voltage sensor 11, the current sensor 12, the temperature sensor 13, and the discharge circuit 15 may not be configured separately, but may be configured by integrating some or all of them.

Here, the control unit 10 refers to the outputs from the voltage sensor 11, the current sensor 12, and the temperature sensor 13, detects the state of the rechargeable battery 14, outputs the information of the detection result to the outside, and outputs the information of the detection result to the outside. The state of charge of rechargeable battery 14 is controlled by controlling the generated voltage of 16 . The voltage sensor 11 detects the terminal voltage of the rechargeable battery 14 and supplies it to the controller 10 as a voltage signal. The current sensor 12 detects the current flowing through the rechargeable battery 14 and supplies it to the controller 10 as a current signal. The temperature sensor 13 detects the electrolyte of the rechargeable battery 14 or the ambient temperature of the rechargeable battery 14 and supplies it to the controller 10 as a temperature signal. Instead of the control unit 10 controlling the voltage generated by the alternator 16 to control the state of charge of the rechargeable battery 14, for example, an ECU (Electric Control Unit) (not shown) may control the state of charge. good.

The rechargeable battery 14 is composed of a rechargeable battery having an electrolytic solution, such as a lead-acid battery, a nickel-cadmium battery, or a nickel-hydrogen battery, and is charged by an alternator 16 to drive a starter motor 18 to start the engine. Also, power is supplied to the load 19 . Note that the rechargeable battery 14 is configured by connecting a plurality of cells in series.

The discharge circuit 15 is composed of, for example, a semiconductor switch and a resistance element connected in series, and turns on/off the semiconductor switch according to the control of the control unit 10 to discharge the rechargeable battery 14 with a predetermined current. .

Alternator 16 is driven by engine 17 to generate AC power which is converted to DC power by a rectifier circuit to charge rechargeable battery 14 . The alternator 16 is controlled by the controller 10 and is capable of adjusting the generated voltage.

The engine 17 is configured by, for example, a reciprocating engine such as a gasoline engine and a diesel engine, a rotary engine, or the like, and is started by a starter motor 18 to drive drive wheels through a transmission to provide propulsion to the vehicle. to generate electric power. The starter motor 18 is composed of, for example, a direct-current motor, and generates rotational force from electric power supplied from the rechargeable battery 14 to start the engine 17 .

The load 19 includes, for example, an electric steering motor, a defogger, a seat heater, an ignition coil, a car audio system, a car navigation system, and the like, and operates with power supplied from the rechargeable battery 14 . In the example of FIG. 1, only the engine 17 is configured to output the driving force, but for example, a hybrid vehicle equipped with an electric motor that assists the engine 17 may be used. In the case of a hybrid vehicle, the rechargeable battery 14 activates a high voltage system (system for driving an electric motor) composed of a lithium battery or the like, and the high voltage system starts the engine 17 .

FIG. 2 is a diagram showing a detailed configuration example of the control unit 10 shown in FIG. As shown in this figure, the control unit 10 includes a CPU (Central Processing Unit) 10a, a ROM (Read Only Memory) 10b, a RAM (Random Access Memory) 10c, a communication unit 10d, an I/F (Interface) 10e, and It has a bus 10f. Here, the CPU 10a controls each section based on a program 10ba stored in the ROM 10b. The ROM 10b is composed of a semiconductor memory or the like, and stores programs 10ba and the like. The RAM 10c is configured by a semiconductor memory or the like, and stores data generated when executing the program 10ba and data 10ca such as tables. The communication unit 10d communicates with an ECU (Electronic Control Unit) or the like, which is a host device, and notifies the host device of detected information or control information. The I/F 10e converts the signals supplied from the voltage sensor 11, the current sensor 12, and the temperature sensor 13 into digital signals and takes them in, and supplies drive currents to the discharge circuit 15, the alternator 16, the starter motor 18, and the like. supply and control these. The bus 10f is a group of signal lines for interconnecting the CPU 10a, ROM 10b, RAM 10c, communication section 10d, and I/F 10e and enabling information exchange therebetween.

In addition, although one CPU 10a is provided in the example of FIG. 2, distributed processing may be executed by a plurality of CPUs. Further, instead of the CPU, a DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), or the like may be used. Alternatively, the processing may be performed by a computer on a server using a general-purpose processor or cloud computing that executes the functions by loading a software program. In addition, although the ROM 10b and the RAM 10c are provided in FIG. 2, for example, a storage device other than these (for example, an HDD (Hard Disk Drive) which is a magnetic storage device) may be used.

(B) Description of the operation of the first embodiment of the present invention Next, the operation of the first embodiment of the present invention will be described. In the following, after the operation of the first embodiment of the present invention is explained, the processing of the flowchart for realizing such an operation will be explained.

First, the outline of the operation of the first embodiment of the present invention will be described. An ignition switch (not shown) is operated to stop the engine 17 of the vehicle, and after a predetermined period of time (for example, several hours) elapses, for example, when the polarization and stratification of the rechargeable battery 14 are eliminated, the control unit The CPU 10 a of 10 refers to the voltage signal supplied from the voltage sensor 11 and measures the voltage V0 of the rechargeable battery 14 .

Next, the CPU 10a of the control unit 10 supplies a control signal to the discharge circuit 15 to cause the rechargeable battery 14 to pulse-discharge. FIG. 3 is a diagram for explaining a specific example of pulse discharge. The horizontal axis of FIG. 3 indicates time (sec), and the vertical axis indicates the discharge current (A) flowing from the rechargeable battery 14 to the discharge circuit 15 . In FIG. 3, the solid line indicates the change in current when the SOC of the rechargeable battery 14 is 100%, the dashed line with short intervals indicates the change in current when the SOC is 80%, and the dashed line with long intervals indicates the SOC. is 40%, and the one-dot chain line shows the current change when SOC is 0%. As shown in FIG. 3, when the square-wave pulse discharge is started, the current (I0≈0A), which was about 0A before the discharge, becomes about 5A (I1≈5A). At this time, since the internal resistance differs depending on the SOC of the rechargeable battery 14, the discharge current also differs.

The CPU 10a refers to the voltage signal supplied from the voltage sensor 11 and detects the voltage V1 of the rechargeable battery 14 after a certain period of time has passed since the pulse discharge is completed.

FIG. 4 shows the change in voltage over time when the rechargeable battery 14 is pulse-discharged. In FIG. 4, the horizontal axis indicates time (sec), and the vertical axis indicates voltage change (V) (for example, change from a predetermined reference voltage (for example, 12 V)). In FIG. 4, the solid line indicates the change in voltage when the SOC of the rechargeable battery 14 is 100%, the dashed line with short intervals indicates the change in voltage when the SOC is 80%, and the dashed line with long intervals indicates the SOC. is 40%, and the one-dot chain line shows the voltage change when SOC is 0%. As shown in FIG. 4, when the SOC decreases from 80%, the voltage change increases accordingly, but when the SOC reaches 100%, the voltage change increases without decreasing.

FIG. 5 is a diagram showing the relationship between the difference value ΔV (=V1−V0) between the voltages V0 and V1 shown in FIG. 4 and the SOC. In the example shown in FIG. 5, up to 80% SOC, the difference value ΔV increases as the SOC increases, but when the SOC exceeds 80%, the difference value ΔV starts to decrease.

That is, the difference value ΔV between the voltage V0 before the pulse discharge and the voltage V1 after the pulse discharge increases as the SOC increases, but stops increasing and decreases when the SOC approaches full charge. As a result of the experiment, such tendency was observed regardless of the size, type, and manufacturer of the rechargeable battery 14 .

Therefore, in the first embodiment, the state of charge of the rechargeable battery 14 is detected based on the difference value ΔV between the voltages before and after the pulse discharge and the state of charge or discharge of the rechargeable battery 14 based on the characteristics described above. do.

Next, an example of processing executed in the first embodiment shown in FIG. 1 will be described with reference to FIG. When the process of the flowchart shown in FIG. 6 is started, the following steps are executed.

In step S10, the CPU 10a of the control unit 10 determines whether or not the engine 17 has been stopped. If it is determined that the engine 17 has been stopped (step S10: Y), the process proceeds to step S11; At step S10:N), the process is terminated. For example, the CPU 10a determines whether or not an ignition switch for stopping the engine 17 has been operated by making an inquiry to an ECU (Electric Control Unit) (not shown) via the communication unit 10d. When it is determined that the engine 17 has been stopped, the process proceeds to step S11.

In step S11, the CPU 10a determines whether or not a predetermined time (for example, several hours) has elapsed since the engine 17 was stopped. Otherwise (step S11: N), the same process is repeated.

In step S12, the CPU 10a refers to the voltage signal supplied from the voltage sensor 11 and measures the pre-discharge voltage V0 of the rechargeable battery .

In step S13, the CPU 10a supplies a control signal to the discharge circuit 15 to cause the rechargeable battery 14 to pulse-discharge. The pulse discharge may be, for example, a discharge having a rectangular waveform, a current value of about several amperes (for example, 1 A to 10 A), and a time width of several tens to several hundred msec. can. Of course, waveforms or numerical values other than these may be set.

In step S14, the CPU 10a determines whether or not a predetermined time (for example, several tens of milliseconds to several hundreds of milliseconds) has passed after executing the pulse discharge. If it is determined that the predetermined time has passed (step If S14: Y), the process proceeds to step S15, otherwise (step S15: N), the same process is repeated.

In step S15, the CPU 10a refers to the voltage signal supplied from the voltage sensor 11 and measures the post-discharge voltage V1 of the rechargeable battery .

In step S16, the CPU 10a calculates the difference value ΔV=V1−V0 between the pre-discharge voltage V0 measured in step S12 and the post-discharge voltage V1 measured in step S15. The difference value ΔV thus obtained is stored in the RAM 10c as data 10ca.

In step S17, the CPU 10a determines whether or not the charge/discharge balance from the previous measurement is positive. At step S17: N), the process is terminated. For example, as shown in FIG. 7, when the charge/discharge balance becomes positive in the next "charge/discharge stop" period after the "charge/discharge stop" period in which the process shown in FIG. 6 is executed, that is, If the rechargeable battery 14 has been charged since the previous "stop charging/discharging" period (if the SOC has increased), the determination is Y and the process proceeds to step S18. As a method of calculating the balance of charge/discharge, the balance can be calculated by causing the CPU 10a to cumulatively add the current signals supplied from the current sensor 12. FIG.

In step S18, the CPU 10a acquires from the RAM 10c the difference value .DELTA.V calculated during the previous "stop charging/discharging" period, and substitutes it for .DELTA.V0.

In step S19, the CPU 10a calculates the difference value ΔV calculated during the current "stop charging/discharging" period (first time point) and the difference value ΔV calculated during the previous "stop charging/discharging" period (second time point). ΔV0 is compared to determine whether or not ΔV<ΔV0 is satisfied. If it is determined that ΔV<ΔV0 is satisfied, the process proceeds to step S20, otherwise the process ends.

In step S20, the CPU 10a determines that the rechargeable battery 14 is nearly fully charged. More specifically, in step S17, when the rechargeable battery 14 is charged during the period from the previous "stop charging/discharging" period to the current "stop charging/discharging" period, ΔV<ΔV0 is satisfied, it is determined that the rechargeable battery 14 exists in the region where the slope of the graph shown in FIG. 5 is negative. Information indicating that the battery is almost fully charged is notified to an ECU (not shown) via the communication unit 10d, for example. The ECU that has received such notification can reduce the load on the engine 17 by reducing the output voltage of the alternator 16, for example, thereby improving fuel efficiency.

As described above, according to the first embodiment of the present invention, the voltage before and after the pulse discharge is measured, and the state of the rechargeable battery 14 is detected based on the increase or decrease of the difference between them. , status can be detected regardless of the size, type, or manufacturer of the rechargeable battery 14 .

(C) Description of Configuration of Second Embodiment of the Present Invention Next, a configuration example of the second embodiment of the present invention will be described. Although the configuration example of the second embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2, the processing executed by the control unit 10 is different.

(D) Description of Operation of Second Embodiment of the Present Invention Next, operation of the second embodiment of the present invention will be described. In the first embodiment, as shown in FIG. 4, the voltage V0 before the start of the pulse discharge and the voltage V1 after the end of the pulse discharge are measured, and the state of the rechargeable battery 14 is detected based on the difference value ΔV between them. However, in the second embodiment, as shown in FIG. 8, the state of the rechargeable battery 14 is detected based on the difference value ΔV between the voltage V0 before the start of discharging and the voltage V1p before the end of discharging. The timing for measuring the voltage V1p before the end of the discharge can be, for example, the timing within about 20% before the end of the pulse discharge. Of course, other timings (for example, within about 50 to 30%) may be used.

FIG. 9 is a diagram showing a change due to SOC of the difference value ΔV between the voltage V0 before the start of discharge and the voltage V1p before the end of discharge. The horizontal axis of FIG. 9 indicates the SOC, and the vertical axis indicates the difference value ΔV. As shown in FIG. 9, the difference value ΔV increases as the SOC increases when the SOC is less than 80%, but begins to decrease when the SOC exceeds 80%. Therefore, when the SOC of rechargeable battery 14 increases and difference value ΔV changes from increasing to decreasing, it can be determined that rechargeable battery 14 is nearly fully charged.

As described above, according to the second embodiment of the present invention, the voltage before and during pulse discharge is measured, and based on the increase/decrease in the difference between these voltages and the charge/discharge balance, the rechargeable battery Since the state of 14 is detected, the state can be detected regardless of the size, type, and manufacturer of the rechargeable battery 14 .

(E) Description of the configuration of the third embodiment of the present invention Next, the configuration of the third embodiment of the present invention will be described. The configuration of the third embodiment is similar to that of the first embodiment shown in FIGS. 1 and 2, but the processing executed by the control unit 10 is different.

(F) Description of the operation of the third embodiment of the present invention Next, the operation of the third embodiment of the present invention will be described. In the first and second embodiments, the voltage V0 before pulse discharge and the voltages V1p and V1 during or after pulse discharge are measured, and the state of rechargeable battery 14 is detected based on the difference value ΔV between them. However, in the third embodiment, the internal resistance R is obtained from the voltage difference value ΔV and the current difference value ΔI, and the state of the rechargeable battery 14 is detected based on the internal resistance R.

More specifically, when the voltage and current before the start of the pulse discharge are V0 and I0, and the voltage and current before the end of the pulse discharge are V1p and I1p, the internal resistance R=(V1p-V0)/(I1p-I0). defined as

FIG. 10 is a diagram showing the relationship between the internal resistance R obtained as described above and time. More specifically, the horizontal axis of FIG. 10 indicates time (sec), and the vertical axis indicates internal resistance (mΩ). In FIG. 10, the solid line indicates the change in internal resistance when the SOC of the rechargeable battery 14 is 100%, the dashed line with short intervals indicates the change in internal resistance when the SOC is 80%, and the dashed line with long intervals indicates the change in internal resistance when the SOC is 80%. indicates the change in internal resistance when the SOC is 40%, and the one-dot chain line indicates the change in internal resistance when the SOC is 0%.

FIG. 11 is a diagram showing the relationship between SOC and changes in internal resistance. More specifically, the horizontal axis of FIG. 11 indicates SOC (%), and the vertical axis indicates internal resistance change (mΩ). As shown in FIG. 11, when the SOC is less than 80%, the internal resistance R decreases as the SOC increases, and when the SOC exceeds 80%, the internal resistance R begins to increase. Therefore, for example, when the charge/discharge balance of the rechargeable battery 14 is positive and the change in the internal resistance R changes from a decrease to an increase, the SOC shown in FIG. 11 belongs to the region exceeding 80%. It can be determined that the battery is in a state close to full charge.

As described above, according to the third embodiment of the present invention, the internal resistance is calculated from the voltage and current before, during, or after pulse discharge, and the internal resistance increases or decreases and the charge/discharge balance is calculated. Therefore, the state of the rechargeable battery 14 can be detected regardless of the size, type, and manufacturer of the rechargeable battery 14 .

(G) Description of the configuration of the fourth embodiment of the present invention Next, the configuration of the fourth embodiment of the present invention will be described. The configuration of the fourth embodiment is similar to that of the first embodiment shown in FIGS. 1 and 2, but the processing executed by the control unit 10 is different.

(H) Description of Operation of Fourth Embodiment of the Present Invention Next, operation of the fourth embodiment of the present invention will be described. In the first and second embodiments, one pulse discharge is performed, the voltage V0 before the pulse discharge and the voltage V1 during or after the pulse discharge are measured, and based on the difference value ΔV of these, the rechargeable battery 14, but in the fourth embodiment, as shown in FIG. 12, pulse discharge is performed a plurality of times (five times in FIG. 12), and the voltage V0 before these pulse discharges is detected. Then, difference values ΔV1 to ΔV5 of voltages V1 to V5 after a predetermined time has passed since the end of each pulse discharge are obtained, and the state of the rechargeable battery 14 is detected based on changes in these difference values ΔV1 to ΔV5. The cycle of pulse discharge can be set to 1/2 sec, for example. Of course, other periods (eg, 1 to 1/100 sec) may be set. Also, the number of pulse discharges is set to five in FIG. 12, but can be set to any number of times greater than or equal to two as long as the SOC of the rechargeable battery 14 does not decrease due to discharge.

FIG. 13 is a diagram showing the relationship between the SOC and the difference value ΔV when pulse discharge is performed multiple times. The horizontal axis of FIG. 13 indicates the SOC (%), and the vertical axis indicates the difference value ΔV (V). Further, the solid polygonal line indicates the change due to SOC of ΔV1=V1-V0, the broken line with a short interval indicates the change due to SOC of ΔV2=V2-V0, and the broken line with a long interval indicates the change due to SOC of ΔV3=V3-V0. The broken dashed dotted line shows the change due to SOC of ΔV4=V4−V0, and the broken double-dotted line shows the change due to SOC of ΔV5=V5−V0. As shown in FIG. 13, when pulse discharge is performed a plurality of times, the greater the number of pulse discharges, the greater the slope of the polygonal line, making it easier to detect the state of rechargeable battery 14 .

As described above, according to the fourth embodiment of the present invention, the pulse discharge is performed a plurality of times, the difference value is calculated from the voltage before the pulse discharge and the voltage after each pulse discharge, and the difference value is calculated. Since the state of the rechargeable battery 14 is detected based on the increase/decrease and the balance of charge/discharge, the state can be detected regardless of the size, type, and manufacturer of the rechargeable battery 14.例文帳に追加

(I) Description of the configuration of the fifth embodiment of the present invention Next, the configuration of the fifth embodiment of the present invention will be described. The configuration of the fifth embodiment is similar to that of the first embodiment shown in FIGS. 1 and 2, but the processing executed by the control unit 10 is different.

(J) Description of the operation of the fifth embodiment of the present invention Next, the operation of the fifth embodiment of the present invention will be described. In the fourth embodiment, pulse discharge is performed a plurality of times, and the state of the rechargeable battery 14 is detected based on the difference values ΔV1 to ΔV5 between the voltage V0 before the pulse discharge and the voltages V1 to V5 after the pulse discharge. However, in the fifth embodiment, as shown in FIG. 14, the pulse discharge is performed a plurality of times (five times in FIG. 14), and the voltage V0 before the plurality of pulse discharges and the voltage V0 during each pulse discharge ΔV1 to ΔV5 of the voltages V1p to V5p are obtained, and the state of the rechargeable battery 14 is detected based on changes in these difference values ΔV1 to ΔV5. The period of pulse discharge can be set to, for example, 1/2 sec, as in the fourth embodiment described above. Of course, other periods (eg, 1 to 1/100 sec) may be set. Also, the number of pulse discharges is set to five in FIG. 14, but can be set to any number of times greater than or equal to two as long as the SOC of the rechargeable battery 14 does not decrease due to discharge.

FIG. 15 is a diagram showing the relationship between the SOC and the difference value ΔV when pulse discharge is performed multiple times. The horizontal axis of FIG. 15 indicates the SOC (%), and the vertical axis indicates the difference value ΔV (V). Further, the solid polygonal line indicates the change due to SOC of ΔV1=V1-V0, the broken line with a short interval indicates the change due to SOC of ΔV2=V2-V0, and the broken line with a long interval indicates the change due to SOC of ΔV3=V3-V0. The broken dashed dotted line shows the change due to SOC of ΔV4=V4−V0, and the broken double-dotted line shows the change due to SOC of ΔV5=V5−V0. As shown in FIG. 15, when pulse discharge is performed a plurality of times, the greater the number of pulse discharges, the greater the slope of the polygonal line, making it easier to detect the state of rechargeable battery 14 .

As described above, according to the fifth embodiment of the present invention, the pulse discharge is executed a plurality of times, the difference value is calculated from the voltage before the pulse discharge and during each pulse discharge, and the difference value is increased or decreased. Since the state of the rechargeable battery 14 is detected based on the charge/discharge balance, the state can be detected regardless of the size, type, and manufacturer of the rechargeable battery 14.例文帳に追加

(K) Description of the configuration of the sixth embodiment of the present invention Next, the configuration of the sixth embodiment of the present invention will be described. The configuration of the sixth embodiment is similar to that of the first embodiment shown in FIGS. 1 and 2, but the processing executed by the control unit 10 is different.

(L) Explanation of the operation of the sixth embodiment of the present invention Next, the operation of the sixth embodiment of the present invention will be explained. In the fifth embodiment, pulse discharge is performed a plurality of times, and the state of the rechargeable battery 14 is detected based on the difference between the voltage V0 before pulse discharge and the voltages V1 to V5 during discharge. In the sixth embodiment, as shown in FIG. 16, pulse discharge is performed a plurality of times (five times in FIG. 16), voltage V0 and current I0 before pulse discharge, voltages V1 to V5 and current values during pulse discharge. Internal resistances R1-R5 are detected based on I1-I5, and the state of rechargeable battery 14 is detected based on these internal resistances R1-R5. The period of pulse discharge can be set to, for example, 1/2 sec, as in the fourth embodiment described above. Of course, other periods (eg, 1 to 1/100 sec) may be set. The number of pulse discharges is set to five in FIG. 16, but can be set to any number of times greater than or equal to two as long as the SOC of the rechargeable battery 14 does not decrease due to discharge.

FIG. 17 is a diagram showing the relationship between internal resistances R1 to R5 and SOC when pulse discharge is performed a plurality of times. The horizontal axis of FIG. 17 indicates SOC (%), and the vertical axis indicates internal resistance (mΩ). In addition, the solid broken line shows the change due to SOC of R1 = (V1 - V0) / (I1 - I0), and the broken broken line with short intervals shows the change due to SOC of R2 = (V2 - V0) / (I2 - I0) , and the broken line with a long interval shows the change due to SOC of R3 = (V3 - V0) / (I3 - I0), and the broken line with a dashed line shows the change of R4 = (V4 - V0) / (I4 - I0) The change due to SOC is shown, and the two-dot chain line shows the change due to SOC of R5=(V5-V0)/(I5-I0). As shown in FIG. 17, when pulse discharge is performed a plurality of times, the greater the number of pulse discharges, the greater the slope of the polygonal line, making it easier to detect the state of rechargeable battery 14 .

As described above, according to the sixth embodiment of the present invention, pulse discharge is performed a plurality of times, and the internal resistance is calculated from the voltage and current before and during each pulse discharge. Since the state of the rechargeable battery 14 is detected based on the increase or decrease, the state can be detected regardless of the size, type, and manufacturer of the rechargeable battery 14 .

(M) Actual Measurement Results Next, actual measurement results according to each embodiment of the present invention will be described. As shown in FIG. 18, during the charging stop period (the period in which the ignition switch is operated and the engine 17 is stopped), the target rechargeable battery 14 is pulse-discharged, and the state of the rechargeable battery 14 is detected. shall be The state of the rechargeable battery 14 during each charging stop period is referred to as states A to C. State A is a state of SOC=40%, state B is a state of SOC=80%, and state C is a state of SOC=100. %.

FIG. 19 shows the results of actual measurement of the rechargeable battery 14 of EN (European Norm) standard size class LN2 in charge/discharge cycles as shown in FIG. The horizontal axis of FIG. 19 indicates time (sec), and the vertical axis indicates voltage change (V). In FIG. 19, the solid curve shows the voltage change due to pulse discharge in state A, the short dashed curve shows the voltage change due to pulse discharge in state B, and the long dashed curve shows the pulse discharge in state C. It shows the voltage change due to discharge.

FIG. 20 shows the relationship between the state of rechargeable battery 14 shown in FIG. 19 and voltage V1-V0. As shown in FIG. 20, the rechargeable battery 14 of EN standard size class LN2 has V1-V0 (=ΔV) when transitioning from state A (SOC=40%) to state B (SOC=80%). increases, but V1-V0 decreases when transitioning from state B to state C (SOC=100%). Therefore, when the charge/discharge balance is positive (charge amount>discharge amount) in the charge/discharge section shown in FIG. 18, and the voltage V1-V0 is negative, the rechargeable battery 14 is nearly fully charged It can be determined that it is in a state (state of 80%<SOC≦100%).

Next, FIG. 21 shows the results of actual measurement of the rechargeable battery 14 of EN standard size class LN5 in charge/discharge cycles as shown in FIG. The horizontal axis of FIG. 21 indicates time (sec), and the vertical axis indicates voltage change (V). Further, in FIG. 21, the solid line curve shows the voltage change due to the pulse discharge in the state A, the short dashed line curve shows the voltage change due to the pulse discharge in the state B, and the long dashed line curve shows the pulse discharge in the state C. It shows the voltage change due to discharge.

FIG. 22 shows the relationship between the state of rechargeable battery 14 shown in FIG. 21 and voltage V1-V0 (=ΔV). As shown in FIG. 22, in the EN standard size class LN5 rechargeable battery 14, V1-V0 increases when transitioning from state A (SOC=40%) to state B (SOC=80%). , V1-V0 decreases when transitioning from state B to state C (SOC=100%). Therefore, when the charge/discharge balance is positive (charge amount>discharge amount) in the charge/discharge section shown in FIG. 18, and the voltage V1-V0 is negative, the rechargeable battery 14 is nearly fully charged It can be determined that it is in a state (state of 80%<SOC≦100%).

Next, FIG. 23 shows the result of actual measurement of the rechargeable battery 14 (degraded rechargeable battery for idling stop) of the JIS (Japanese Industrial Standard) standard battery type M-42 in the charge and discharge cycle as shown in FIG. is shown. The horizontal axis of FIG. 23 indicates time (sec), and the vertical axis indicates voltage change (V). Further, in FIG. 23, the solid line curve shows the voltage change due to the pulse discharge in the state A, the short dashed line curve shows the voltage change due to the pulse discharge in the state B, and the long dashed line curve shows the pulse discharge in the state C. It shows the voltage change due to discharge.

FIG. 24 shows the relationship between the state of rechargeable battery 14 shown in FIG. 23 and voltage V1-V0. As shown in FIG. 24, the JIS standard battery type M-42 rechargeable battery 14 increases V1-V0 when transitioning from state A (SOC=40%) to state B (SOC=80%). However, when transitioning from state B to state C (SOC=100%), V1-V0 decreases. Therefore, when the charge/discharge balance is positive (charge amount>discharge amount) in the charge/discharge section shown in FIG. 18, and the voltage V1-V0 is negative, the rechargeable battery 14 is nearly fully charged It can be determined that it is in a state (state of 80%<SOC≦100%).

Next, FIG. 25 shows the results of measuring the internal resistance of the JIS standard battery type M-42 rechargeable battery 14 (rechargeable battery deteriorated due to idling stop) in charge and discharge cycles as shown in FIG. ing. The horizontal axis of FIG. 25 indicates time (sec), and the vertical axis indicates internal resistance (mΩ). Further, in FIG. 25, the solid curve shows the change in internal resistance due to pulse discharge in state A, the short dashed curve shows the change in internal resistance due to pulse discharge in state B, and the long dashed curve shows A change in internal resistance due to pulse discharge in state C is shown.

FIG. 26 is a diagram showing the relationship between the state of rechargeable battery 14 shown in FIG. 25 and the internal resistance. As shown in FIG. 26, the internal resistance of the rechargeable battery 14 of the JIS standard battery type M-42 decreases when transitioning from state A (SOC=40%) to state B (SOC=80%). However, when transitioning from state B to state C (SOC=100%), the internal resistance increases. Therefore, when the charge/discharge balance is positive (charging amount>discharging amount) in the charging/discharging section shown in FIG. %<SOC≦100%).

(C) Description of Modified Embodiment The above-described embodiment is merely an example, and needless to say, the present invention is not limited to the case described above. For example, in each of the above embodiments, the state of charge of the rechargeable battery 14 is determined based on the difference value ΔV between the voltage V0 before pulse discharge and the voltage V1 during or after pulse discharge. , the ratio of the voltages V0 and V1 (for example, V1/V0) may be used instead of the difference value. That is, the "variation value" in the claims includes not only the difference value but also the ratio.

Further, in each of the above embodiments, the state of charge is determined by the difference value ΔV when the charge/discharge balance is positive or the increase or decrease in the internal resistance R, but the difference when the charge/discharge balance is negative The state of charge may be determined by increasing or decreasing the value ΔV or the internal resistance R. More specifically, for example, in FIG. 5, when the charge/discharge balance is negative (when the SOC decreases), if the difference value ΔV increases, it is determined to be in the range of 80<SOC≦100. can do. The same applies to other embodiments.

In each of the above embodiments, the temperature of the rechargeable battery 14 is not taken into consideration. 25° C.), and the state may be determined based on the corrected voltage or internal resistance. As a method of correcting to the reference temperature, a relational expression or table indicating the relationship between temperature and voltage or internal resistance is stored in the RAM 10c as data 10ca, and correction can be performed based on the relational expression or table.

Also, the flowchart shown in FIG. 6 is an example, and the present invention is not limited only to the processing of these flowcharts.

1 Rechargeable Battery State Detector 10 Control Unit 10a CPU
10b ROM
10c RAM
10d communication unit 10e I/F
11 voltage sensor 12 current sensor 13 temperature sensor 14 rechargeable battery 15 discharge circuit 16 alternator 17 engine 18 starter motor 19 load

Claims (3)

In a rechargeable battery state detection device that detects the state of a rechargeable battery,
a control means for supplying a control signal to a discharge circuit for discharging the rechargeable battery to pulse-discharge the rechargeable battery;
Receiving means for receiving a voltage signal from a voltage sensor that detects the terminal voltage of the rechargeable battery and a current signal from a current sensor that detects the charge/discharge current of the rechargeable battery;
With reference to the voltage signal received by the receiving means, the voltage before pulse discharge of the rechargeable battery by the discharge circuit and the voltage of the rechargeable battery after a predetermined time has passed after the pulse current is stopped in the pulse discharge. a detection means for detecting a difference value from the voltage of
determining means for determining whether the rechargeable battery has been charged or discharged between a first point in time and a second subsequent point in time with reference to the current signal received by the receiving means;
Judgment results of charge/discharge of the rechargeable battery between the first time point and the second time point, and a first difference value and a second difference value respectively detected by the detecting means at the first time point and the second time point and, if the determining means determines that the rechargeable battery is charged between the first time point and the second time point, the detecting means or the determination means determines that the rechargeable battery is discharged between the first time point and the second time point estimating means for determining that the rechargeable battery is in a nearly fully charged state when the second difference value detected by the detecting means is larger than the first difference value detected by the detecting means;
an output means for outputting an estimation result of the estimation means;
A rechargeable battery state detection device comprising: The control means causes the discharge circuit to perform pulse discharge a plurality of times,
The detecting means detects the charging voltage before the discharge of the plurality of pulse discharges and at the time when a predetermined time has passed after the pulse current of the second and subsequent pulse discharges is stopped so that the change in the difference value of the voltage becomes larger. Detecting the difference value with the voltage of the possible battery,
2. The rechargeable battery state detection device according to claim 1, wherein: In a rechargeable battery state detection method for detecting a state of a rechargeable battery,
a control step of supplying a control signal to a discharge circuit for discharging the rechargeable battery to pulse discharge the rechargeable battery;
a receiving step of receiving a voltage signal from a voltage sensor that detects a terminal voltage of the rechargeable battery and a current signal from a current sensor that detects a charge/discharge current of the rechargeable battery;
With reference to the voltage signal received in the receiving step, the voltage before pulse discharging the rechargeable battery by the discharge circuit and the rechargeable battery at the time when a predetermined time has passed after the pulse current is stopped in the pulse discharging. a detection step of detecting a difference value from the voltage of
determining with reference to the current signal received in the receiving step whether the rechargeable battery has been charged or discharged between a first time point and a second time point thereafter;
determination result of charging/discharging of the rechargeable battery between the first time point and the second time point; and, if it is determined in the determining step that the rechargeable battery is charged between the first time point and the second time point, the detecting step or when the second difference value is smaller than the first difference value detected in the step of determining, it is determined that the rechargeable battery is discharged between the first time point and the second time point in the determining step. an estimating step of determining that the rechargeable battery is in a nearly fully charged state when the second difference value is greater than the first difference value detected in the detecting step;
an output step of outputting an estimation result of the estimation step;
A rechargeable battery state detection method, comprising:

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