JP2023131187A - Lead battery management device, lead battery system, and lead battery management method - Google Patents

Abstract

To provide a management device for lead batteries that properly detects deterioration of lead batteries, a lead battery system using the same, and a lead battery management method.SOLUTION: A lead battery management device includes an acquisition unit that acquires charging current and discharging current of a lead battery, a storage unit, a processing unit that stores information in the storage unit, and an output unit. The processing unit obtains a cycle number of the lead battery based on charging current and discharging current, calculates a cumulative discharge amount of the lead battery based on the discharge current, causes the storage unit to store the number of cycles and the cumulative discharge amount, and causes the output unit to output a battery life notice when at least either the number of cycles or the cumulative discharge amount reaches a preset notice threshold.SELECTED DRAWING: Figure 4

Description

One aspect of the present invention relates to a management device for lead-acid batteries, a lead-acid battery system using the same, and a lead-acid battery management method.

Lead-acid batteries have been widely used for power backup in emergencies such as power outages. In this application, lead-acid batteries are float charged and discharged only in emergencies, so the number of discharges and subsequent charges is not very large.

In recent years, lead-acid batteries have been increasingly used in applications where charging and discharging are repeated on a daily basis (cycle applications), such as peak shifting and energy management. In response to this need, lead-acid batteries suitable for cycle applications have been developed.

Patent Document 1 discloses a technique for utilizing a storage battery included in an uninterruptible power supply (UPS) for demand control and negawatt trading.

Patent No. 6402924

In a typical storage battery system using lithium-ion batteries, battery cells connected in series are monitored (measuring voltage and temperature) by multiple cell management units (CMUs), and these cell management units (BMU) to collect measurement data. The BMU or a computer that receives measurement data from the BMU detects deterioration of the battery cells due to operation based on the measurement data.

In lead-acid battery systems, the deterioration behavior of lead-acid batteries during operation is significantly different from that when using lithium-ion batteries. In a lead-acid battery, the active material deteriorates even when charging and discharging are repeated at a shallow depth of discharge and the integrated value of the amount of discharged electricity is not so large. There is still room for improvement in the proper detection of deterioration associated with operation in lead-acid battery systems for cycle applications.

One aspect of the present invention provides a management device for lead-acid batteries that appropriately detects deterioration of lead-acid batteries, a lead-acid battery system using the same, and a lead-acid battery management method.

A lead-acid battery management device according to one aspect of the present invention includes an acquisition unit that acquires charging current and discharging current of a lead-acid battery, a storage unit, a processing unit that stores information in the storage unit, and an output unit. . The processing unit obtains the number of cycles of the lead-acid battery based on the charging current and the discharging current, calculates the cumulative amount of discharge of the lead-acid battery based on the discharge current, and stores the number of cycles and the number of cycles in the storage unit. A cumulative amount of discharge is stored, and when at least one of the number of cycles and the cumulative amount of discharge reaches a preset warning threshold, the output unit outputs a battery life warning.

According to the above aspect, deterioration of the lead-acid battery can be properly detected and the lead-acid battery system can be stably operated.

FIG. 1 is a diagram showing an overview of a lead-acid battery system. FIG. 1 is a block diagram showing an overview of a lead-acid battery system and a rectifier. FIG. 2 is a block diagram showing an overview of a management device. It is a flowchart which shows the process which obtains the number of cycles and the discharge integrated amount.

The lead-acid battery management device includes an acquisition unit that acquires charging current and discharging current of the lead-acid battery, a storage unit, a processing unit that stores information in the storage unit, and an output unit. The processing unit obtains the number of cycles of the lead-acid battery based on the charging current and the discharging current, calculates the cumulative amount of discharge of the lead-acid battery based on the discharge current, and stores the number of cycles and the number of cycles in the storage unit. A cumulative amount of discharge is stored, and when at least one of the number of cycles and the cumulative amount of discharge reaches a preset warning threshold, the output section outputs a battery life warning.

Here, the "lead acid battery" may be an assembled battery in which a plurality of lead acid batteries are connected in series or connected in series and parallel.
The "accumulated amount of discharge" means the integrated value of the amount of electricity discharged from the lead-acid battery from the start of operation of the lead-acid battery.
The "advance threshold" may be set to a value lower than a lifespan threshold corresponding to the end-of-life (EOL) of a lead-acid battery. For example, when the number of cycles corresponding to the EOL of the lead-acid battery is 5500 cycles, the advance notice threshold may be set to 5000 cycles.

With the lead-acid battery management device having the above configuration, deterioration (signs of deterioration) of the lead-acid battery can be appropriately detected, and the lead-acid battery system can be stably operated.
In a lead-acid battery system for cycle use, if the lead-acid battery reaches the end of its lifespan and is no longer able to perform the desired charging and discharging, system users and customers will experience opportunity losses, such as the inability to reduce electricity charges and the inability to participate in electricity trading. With the above configuration, a battery life notice is output when at least either the number of cycles or the cumulative amount of discharge reaches the notice threshold, so preventive maintenance such as replacing the lead-acid battery can be performed.
As mentioned above, lead-acid batteries have traditionally been widely used for power backup in emergencies. In that application, lead acid batteries are float charged most of the time. Because the number of cycles for lead-acid batteries is very small (e.g., only a few times per month), there is little need to count the number of cycles or to provide lead-acid battery management equipment (i.e., a circuit board) to do so. Ta.
On the other hand, the lead-acid battery management device configured as described above grasps the operation status of the battery in detail, similar to the battery management device for lithium ion batteries. This lead-acid battery management device has a function of obtaining and storing the number of cycles of a lead-acid battery. This makes it possible to apply lead-acid batteries to systems with cyclical applications (peak shifting and energy management) that repeat charging and discharging on a daily basis, unlike emergency applications. The system can be operated stably.

The processing section may increase the number of cycles to be stored in the storage section when the amount of energized electricity equal to or greater than the determination threshold is discharged and charged.

In cyclic applications (industrial applications) such as peak shifting, lead-acid batteries are continuously charged and discharged over a certain period of time, unlike automotive applications that supply power to on-board loads. The present inventors count the number of cycles in a lead-acid battery system for cycle use (industrial use) by increasing (incrementing) the number of cycles when discharging and charging are performed with an amount of electricity that is equal to or greater than a determination threshold. We have discovered that this can be done properly.
Conventionally, there has been a lack of demand for this, so no specific method has been established for counting the number of cycles in lead-acid battery systems. According to the above configuration, it is possible to appropriately count the number of cycles in a lead-acid battery system for cycle use at a small additional cost.

The processing unit causes the storage unit to store information for obtaining the elapsed time from the start of operation of the lead-acid battery, and at least one of the elapsed time, the number of cycles, and the cumulative amount of discharge is set to a preset advance notice threshold. When the battery life reaches the battery life limit, the output unit may output a battery life notice.

With the above configuration, the operational status of the lead-acid battery can be evaluated from multiple aspects and preventive maintenance can be encouraged, thereby making it possible to operate the lead-acid battery system with high reliability.

The processing unit is configured to determine which parameter reaches the threshold when at least one of the elapsed time, the number of cycles, and the cumulative amount of discharge reaches the advance notice threshold or a life threshold set to a value higher than the notice threshold. The storage unit may store information as to whether or not the user has done so.

With the above configuration, appropriate replacement (update) of lead-acid batteries and future operational changes (for example, changes in cycle frequency, changes in upper and lower limit voltages (or upper and lower SOC limits), etc.) can be performed based on operation history data and operation results. , can be proposed to users and customers of lead-acid battery systems.

The lead-acid battery management device may further include a reception unit that receives a setting or change of a prior notice threshold value of at least one of the number of cycles and the cumulative amount of discharge.

With the above configuration, the advance notice threshold can be set or changed after the lead-acid battery management device is shipped from the factory, so it is possible to flexibly meet the needs of individual users and customers.

The lead-acid battery system includes the above-mentioned lead-acid battery management device and a lead-acid battery managed by the lead-acid battery management device.
The lead-acid battery includes a plurality of assembled battery units connected in parallel, and the lead-acid battery management device includes a bank management device that is provided in each assembled battery unit and obtains the number of cycles and cumulative discharge amount of each assembled battery unit; and a domain management device that outputs the battery life notice.

The lead-acid battery management method includes acquiring the charging current and discharging current of the lead-acid battery, obtaining the number of cycles of the lead-acid battery based on the charging current and discharging current, and determining the cumulative discharge amount of the lead-acid battery based on the discharging current. is calculated, and a battery life notice is output when at least one of the number of cycles and the cumulative amount of discharge reaches a preset notice threshold.

The above-mentioned lead-acid battery management method may be implemented by a management device attached to the lead-acid battery, or may be implemented by a computer installed apart from the lead-acid battery, or a mobile terminal device such as a smartphone or tablet.

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the embodiments.

As shown in FIG. 1, the lead acid battery system 100 includes an assembled battery unit U and a monitoring device 110. The assembled battery unit U houses a plurality of lead-acid batteries Pb1, Pb2, . . . connected in series in a metal casing (battery panel) 115. Lead-acid batteries that are suitable for cycle applications are used.

The monitoring device 110 has a monitor 111 and a handle 113 for opening the front door on the front side of a metal casing (monitoring panel). The monitoring device 110 houses both management devices 1D and 1B, which will be described later, in a housing.

The monitoring device 110 may monitor a single assembled battery unit U as shown in FIG. 1, or may monitor a plurality of assembled battery units U as shown in FIG.

FIG. 2 shows the electrical configuration of the lead-acid battery system 100 and the rectifier 4.
The rectifier 4 converts AC power supplied from a commercial power source or the like into DC power using a power converter (AC/DC converter) 3 controlled by a control unit 5, and connects a DC power load (not shown) and a lead-acid battery system 100. supply to.

The lead-acid battery system 100 includes a domain management device 1D and a plurality of assembled battery units U connected in parallel to a common power line Lo extending from the rectifier 4. In this embodiment, five assembled battery units (U1 is the first assembled battery unit, U2 is the second assembled battery unit, and U5 is the fifth assembled battery unit) having the same configuration are connected to each other by the individual power line Lm. It is connected in parallel to the common power line Lo.

Each battery pack unit U includes a battery pack (hereinafter also referred to as a bank) including a plurality of lead-acid batteries Pb1, Pb2, etc. connected in series, a plurality of voltage sensors 33, a current sensor 41, and a current sensor 41. It includes a cutoff device 45 and a bank management device 1B.

Voltage sensor 33 measures the voltage of each lead acid battery Pb. The plurality of voltage sensors 33 of each assembled battery unit U may be mounted on one circuit board (monitoring unit). The voltage sensor 33 or the monitoring unit is connected to the bank management device 1B via a signal line, and transmits voltage measurement data of each lead-acid battery Pb to the bank management device 1B.

The current sensor 41 is provided on the individual power line Lm of each battery pack unit U, and measures the current of a battery pack (bank) in which a plurality of lead-acid batteries are connected in series. The current sensor 41 is connected to the bank management device 1B via a signal line, and transmits current measurement data to the bank management device 1B.

The current interrupt device 45 is controlled to be normally closed during normal operation. The current interrupting device 45 is opened by the bank management device 1B when an abnormality occurs in the assembled battery unit U or during maintenance, and interrupts the current (disconnects the banks).

The domain management device 1D is connected to the bank management device 1B of each assembled battery unit U via a communication bus 120 (for example, a CAN (Controller Area Network) bus or a LAN cable). Data regarding the state of the battery unit U is acquired at predetermined time intervals.

When the monitoring device 110 (see FIG. 1) monitors a single assembled battery unit U, the domain management device 1D is omitted and the bank management device 1B has the functions of the domain management device 1D described below. Good too.

A communication device 25 is connected to the domain management device 1D. The communication device 25 transmits the status data acquired from each bank management device 1B to the outside. The communication device 25 may be an independent device, for example, a router-type communication device, or a network card-type device (network interface card).

The domain management device 1D may be connected to the control unit 5 of the rectifier 4 via a signal line.

FIG. 3 is a block diagram showing the configuration of management devices 1D and 1B. Although the domain management device 1D and the bank management device 1B are shown separately, their configurations are almost the same, and hereinafter they will also be collectively referred to as the management device 1.

The management device 1 (circuit board) includes a processing section 10, a first communication section 11, a second communication section 12, a third communication section 13, a storage section 14, and an input/output section 15.

The processing unit 10 is a microcomputer, and uses a CPU (Central Processing Unit) and built-in memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory) to control each component and execute processing.

The first communication unit 11 is a communication device that realizes communication with the voltage sensor 33 or the monitoring unit and the current sensor 41 (see FIG. 2). The first communication unit 11 of the bank management device 1B functions as an acquisition unit that acquires the charging current and discharging current of each assembled battery unit U. Specifically, the first communication unit 11 is a serial communication interface such as RS-232C.

The second communication unit 12 is a communication device that realizes communication with other management devices 1. The second communication unit 12 is, for example, a communication device that realizes communication on a CAN bus.

The third communication unit 13 is a communication device that realizes communication with the communication equipment 25 (see FIG. 2). The third communication unit 13 uses, for example, a communication interface such as Ethernet (registered trademark) or a wireless communication antenna.

Parts of the first to third communication units 11 to 13 may be incorporated inside the processing unit 10, which is a microcomputer.

The storage unit 14 uses nonvolatile memory such as flash memory. The storage unit 14 stores a management program 1P that the processing unit 10 reads and executes. The management program 1PD stored in the storage unit 14 of the domain management device 1D and the management program 1PB stored in the storage unit 14 of the bank management device 1B have different contents. The management program 1PB and the management program 1PD may be stored in a ROM built into the processing unit 10.

The management program 1PB and the management program 1PD may be rewritable. The management program 1PB or the management program 1PD is obtained by reading out the management program 9PB or the management program 9PD stored in the storage medium 9 by the processing unit 10 via the input/output unit 15, copying it, and storing it in the storage unit 14. There may be.

The storage unit 14 stores communication settings in the first communication unit 11, the second communication unit 12, and the third communication unit 13. The processing unit 10 is capable of communicating with the monitoring unit, other management device 1, and communication device 25 based on communication settings stored in the storage unit 14. The storage unit 14 temporarily or non-temporarily stores the status data acquired from the monitoring unit and the current sensor 41 until it is delivered to the communication device 4.

The input/output unit 15 is a connection interface with external equipment, and includes a plurality of external terminals. The external terminal may include a USB (Universal Serial Bus).

A monitor 111 and an input interface 152 can be connected to the input/output unit 15 of the domain management device 1D. The monitor 111 and the input interface 152 may be integrated using a liquid crystal panel with a built-in touch panel. The monitor 111 and the input interface 152 may be replaced by a maintenance worker's terminal device that has a display and an input interface and is communicatively connected by wire or wirelessly. A wired or wireless communication connection may be made via the communication device 25. The input/output unit 15 and monitor 111 of the domain management device 1D function as an output unit that outputs a battery life notice.

In this embodiment, the bank management device 1B obtains the number of cycles and the cumulative amount of discharge of the lead-acid battery Pb in each assembled battery unit U. The domain management device 1D outputs a battery life notice based on the number of cycles and the cumulative amount of discharge obtained by each bank management device 1B. When at least either the number of cycles or the cumulative amount of discharge reaches a preset warning threshold, a battery life warning is output to the monitor 111 connected to the domain management device 1D. The battery life notice from the domain management device 1D may be output to the outside in the form of an e-mail, message, or web page via the communication device 25 (see FIG. 2), or may be output to the outside in the form of an e-mail, message, or web page, or may be output to a remote monitoring server (not shown). may be sent to.

Since the domain management device 1D that aggregates information from each bank management device 1B outputs the battery life notice, additional costs can be reduced compared to the case where each bank is provided with an output section. When outputting the battery life notice, the output unit of the domain management device 1D may also indicate which assembled battery unit U the battery life notice is for.

The input/output unit 15 and the input interface 152 of the domain management device 1D function as a reception unit that accepts settings or changes of advance notice thresholds for at least one of the number of cycles and the cumulative amount of discharge. The third communication unit 13 may function as a reception unit and accept settings or changes of the advance notice threshold from a remote location. After the management device 1D is shipped from the factory, the advance notice threshold can be set or changed at the site where the lead-acid battery system 100 is installed or remotely, so it is possible to flexibly meet the needs of individual users and customers. Can be done. If the user desires to deeply discharge the lead-acid battery Pb, the advance notice threshold value can be set low; otherwise, the notice threshold value can be set to a standard value. For example, if a cycle at a depth of discharge (DOD) of 70% is expected, the advance notice threshold is set to 5000 cycles, and when a cycle at a DOD of 30 to 50% is expected, the advance notice threshold is set to 5500 cycles.

The domain management device 1D may calculate a total current value (current value flowing through the common power line Lo) by summing the current values of each bank transmitted from each bank management device 1B.
The domain management device 1D may recognize which assembled battery unit U is in operation (or not disconnected from the array), and may output the recognized state to the outside.

Each bank management device 1B increases the number of cycles when the assembled battery unit U is discharged and charged at a rate equal to or higher than a determination threshold value (for example, equal to or higher than 10 ampere hours [Ah]). An example of detecting charging and discharging at a predetermined sampling period will be shown below.
・When discharging, charging, discharging, and charging are performed at or above the determination threshold value, it is counted that two cycles of charging and discharging have been performed.
・If discharge, discharge, charge, discharge, charge is performed at or above the determination threshold value, it is also counted as two cycles of charging and discharging.
・Even when discharging, charging, charging, discharging, and charging are performed at or above the determination threshold value, it is counted as two cycles of charging and discharging.

In this embodiment, the number of cycles is incremented at the timing when switching from discharging to charging, but the present invention is not limited to this, and the number of cycles may be incremented at the timing when switching from charging to discharging.

A method for counting the number of cycles and a method for calculating the cumulative amount of discharge in each bank management device 1B will be described with reference to FIG. 4. Each bank management device 1B may periodically execute the process shown in FIG.

The bank management device 1B determines whether the direction of the current flowing through the individual power line Lm is the same as that when the process was executed last time (step S101), and if it is the same (S101: YES), the current direction at that time is set in the "accumulated amount". The amount of electricity based on the current value is integrated (step S102). The "integrated amount" may be a storage area prepared in the storage unit 14 as a variable or a counter. If the direction of the current flowing through the individual power line Lm is different from that when the process was executed last time (S101: NO), the value of "integrated amount" is reset to zero (step S103), and then the "integrated amount" is set to the current value at that time. The amount of electricity based on the current value is integrated (S102).

The bank management device 1B determines whether the absolute value of the "integrated amount" (the amount of electricity energized in one direction in the assembled battery unit U) is greater than or equal to the determination threshold (step S104). For example, it is determined whether the absolute value of the "integrated amount" is 10 Ah or more.

If the absolute value of the "integrated amount" is equal to or greater than the determination threshold (S104: YES), the bank management device 1B determines whether discharge is occurring from the sign of the current measurement data (Step S105). If discharge is being performed (S105: YES), the "discharge flag" is set to 1 (step S106). The “discharge flag” may be a storage area prepared in the storage unit 14.

If the absolute value of the "integrated amount" (the amount of electricity energized in one direction in the assembled battery unit U) is not equal to or greater than the determination threshold (for example, less than 10 Ah) (S104: NO), the process of counting the number of cycles is terminated. , the process proceeds to the process of calculating the cumulative amount of discharge.

If it is determined from the sign of the current measurement data that discharge is not occurring (S105: NO), it is determined whether the "discharge flag" is 1 (step S107). If the "discharge flag" is 1 (S107: YES), the "discharge flag" is reset to zero, and the number of cycles stored in the storage unit 14 is incremented (step S108). If the "discharge flag" is not 1 (S107: NO), the process of counting the number of cycles is ended, and the process proceeds to the process of calculating the integrated discharge amount.

The bank management device 1B determines whether discharge is occurring based on the sign of the current measurement data (step S109). If discharge is being performed (S109: YES), the amount of discharged electricity is calculated based on the current value at that time, and the integrated amount of discharge stored in the storage unit 14 is updated (Step S110). If discharge is not being performed (S109: NO), the process ends.

The processing unit 10 of the domain management device 1D shown in FIG. 3 further causes the storage unit 14 to store information for obtaining the elapsed time from the start of operation of the lead-acid battery system 100.
The domain management device 1D controls the input/output unit 15 when the elapsed time, the number of cycles in any of the assembled battery units U, or the cumulative amount of discharge in any of the assembled battery units U reaches a preset advance notice threshold. outputs a battery life notice.

The processing unit 10 of the domain management device 1D further determines whether or not any of the groups will It is determined which parameter in the battery unit U has reached the threshold value. The processing unit 10 causes the storage unit 14 to store the grasped information.

The management device 1 described above allows the lead-acid battery system 100 to be stably operated by appropriately detecting deterioration of the lead-acid battery Pb and performing preventive maintenance based on the output battery life notice.

With the configuration in which the number of cycles is incremented when the amount of electricity supplied is discharged and charged in excess of the determination threshold value, the number of cycles in the lead-acid battery system 100 for cycle use can be appropriately counted at a small additional cost.

The lead-acid battery system 100 is operated with high reliability by a configuration that outputs a battery life notice when at least one of the elapsed time from the start of operation, the number of cycles, and the cumulative amount of discharge reaches a preset notice threshold. be able to.

With a configuration that remembers which of the assembled battery units U has reached the advance notice threshold or the lifetime threshold in elapsed time, number of cycles, and cumulative discharge amount, it is possible to provide high value-added proposals to users and customers based on operation history data. Can be done against.

In the embodiment described above, the management devices 1D and 1B are housed in the casing of the monitoring device 110 (see FIG. 1), but the bank management device 1B may be housed in the casing 115 of the assembled battery unit U.

The housing 115 of the assembled battery unit U may accommodate lead-acid batteries Pb corresponding to a plurality of banks.

The lead-acid battery system 100 equipped with a lead-acid battery management device may be used for peak shift or energy management, or may be used for power backup.

1B Bank management device 1D Domain management device 10 Processing section 11 First communication section (acquisition section)
14 Storage unit 15 Input/output unit (output unit)
110 Monitoring device (lead storage battery management device)
111 Monitor (output section)
U Assembled battery unit (lead acid battery)

Claims (8)

an acquisition unit that acquires charging current and discharging current of the lead-acid battery;
storage section and
a processing unit that stores information in the storage unit;
An output section;
The processing unit includes:
Obtaining the number of cycles of the lead-acid battery based on the charging current and discharging current, calculating the cumulative amount of discharge of the lead-acid battery based on the discharging current, and storing the number of cycles and the cumulative amount of discharge in the storage unit. let me,
A lead-acid battery management device that causes the output unit to output a battery life notice when at least one of the number of cycles and the cumulative amount of discharge reaches a preset notice threshold. The lead-acid battery management device according to claim 1, wherein the processing unit increases the number of cycles to be stored in the storage unit when the amount of electricity supplied is equal to or greater than a determination threshold value and is discharged and charged. The processing unit includes:
storing information for obtaining the elapsed time from the start of operation of the lead-acid battery in the storage unit;
The lead-acid battery according to claim 1 or 2, wherein the output unit outputs a battery life notice when any one of the elapsed time, the number of cycles, and the cumulative amount of discharge reaches a preset notice threshold. Management device. The processing unit is configured to determine which parameter reaches the threshold when at least one of the elapsed time, the number of cycles, and the cumulative amount of discharge reaches the advance notice threshold or a life threshold set to a value higher than the notice threshold. 4. The lead-acid battery management device according to claim 3, wherein the storage unit stores information on whether or not the battery has been used. The lead-acid battery management device according to any one of claims 1 to 4, further comprising a reception unit configured to accept a setting or change of a advance notice threshold value of at least one of the number of cycles and the cumulative amount of discharge. A lead-acid battery management device according to any one of claims 1 to 5,
A lead-acid battery system, comprising: a lead-acid battery managed by the lead-acid battery management device. The lead-acid battery includes a plurality of assembled battery units connected in parallel,
The lead-acid battery management device includes a bank management device that is provided in each battery pack unit and obtains the number of cycles and cumulative discharge amount of each battery pack unit, and a domain management device that outputs the battery life notice. Lead acid battery system as described. Obtain the charging current and discharging current of a lead-acid battery,
Obtaining the number of cycles of the lead-acid battery based on the charging current and discharging current, and calculating the cumulative amount of discharge of the lead-acid battery based on the discharging current,
A lead-acid battery management method that outputs a battery life notice when at least one of the number of cycles and the cumulative amount of discharge reaches a preset notice threshold.

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