Lead-acid battery monitoring device and lead-acid battery monitoring method

Abstract

To provide a lead storage battery monitoring device and a lead storage battery monitoring method.SOLUTION: The lead storage battery monitoring device comprises: a plurality of monitoring units 20 attached to a plurality of series or in parallel connected lead storage batteries 1 to measure monitoring data; and a management unit 10 sequentially connected to the plurality of monitoring units 20 via radio communication. The lead storage battery monitoring device performs first monitoring operation of sequentially receiving, from the plurality of monitoring units 20, monitoring data including internal resistance and temperature of each lead storage battery 1 using the management unit 10, and second monitoring operation of sequentially receiving, from the plurality of monitoring units 20, monitoring data including temperature of each lead storage battery 1 using the management unit 10.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a lead-acid battery monitoring device and a lead-acid battery monitoring method. [Background technology]

[0002] Patent Document 1 discloses that in a power storage system, a relay panel is communicatively connected to a higher-level power control device and lower-level storage battery panels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6135767 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present invention provides a lead-acid battery monitoring device and a lead-acid battery monitoring method. [Means for solving the problem]

[0005] A lead-acid battery monitoring device according to one aspect of the present invention includes a plurality of monitoring units attached to a plurality of lead-acid batteries connected in series and / or parallel and configured to measure monitoring data, and a management unit sequentially connected via wireless communication to the plurality of monitoring units. The lead-acid battery monitoring device executes a first monitoring operation in which the management unit sequentially receives monitoring data from the plurality of monitoring units, the monitoring data including the internal resistance and temperature of each lead-acid battery, and a second monitoring operation in which the management unit sequentially receives monitoring data from the plurality of monitoring units, the monitoring data including the temperature (but not the internal resistance) of each lead-acid battery.

[0006] A lead-acid battery monitoring method according to another embodiment of the present invention includes a management unit that sequentially connects via wireless communication to a plurality of monitoring units attached to a plurality of lead-acid batteries connected in series and / or parallel, and performs a first monitoring operation in which the management unit sequentially receives monitoring data from the plurality of monitoring units, the monitoring data including the internal resistance and temperature of each lead-acid battery, and performs a second monitoring operation in which the management unit sequentially receives monitoring data from the plurality of monitoring units, the monitoring data including the temperature (not including the internal resistance) of each lead-acid battery. [Effects of the Invention]

[0007] The above-described embodiment makes it possible to grasp the state of a lead-acid battery with high accuracy by reducing the frequency of measurement of the internal resistance that requires discharging the lead-acid battery, while increasing the frequency of measurement of the temperature that has a significant impact on the deterioration and lifespan of the lead-acid battery. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an overview of a storage battery monitoring device. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control unit. [Figure 3] FIG. 2 is a schematic diagram illustrating communication between a control unit and a sensor unit. [Figure 4] FIG. 10 is a diagram showing a remote monitoring screen on a web browser. [Figure 5] 10 is a flowchart showing an example of a processing procedure in a control unit. [Figure 6] 10 is a flowchart illustrating an example of a processing procedure in the sensor unit. [Figure 7] FIG. 1 is a schematic diagram showing a communication procedure. [Figure 8] FIG. 2 is a diagram illustrating an example of a first monitoring operation and a second monitoring operation. [Figure 9] 10A and 10B are diagrams illustrating other examples of the first monitoring operation and the second monitoring operation. DETAILED DESCRIPTION OF THE INVENTION

[0009] In a power storage system, many storage batteries are connected in series and / or parallel. Some large-scale power storage systems are composed of hundreds of storage batteries. There is a growing need to remotely monitor each storage battery in large-scale power storage systems. To achieve such battery monitoring, multiple monitoring units attached to each storage battery must be wired to a management unit that acquires data from the monitoring units, but this increases the cost of installing a network. There is a need for technology that can achieve remote monitoring of storage batteries while reducing wiring and communication costs.

[0010] Among the short-range wireless communication standards, Bluetooth Low Energy (hereinafter referred to as BLE) is attracting attention for IoT applications. BLE enables wireless communication at low cost.

[0011] An embodiment of a lead-acid battery monitoring device will be described below with reference to the drawings. The lead-acid battery monitoring device shown in Fig. 1 includes a plurality of sensor units (monitoring units) 20 attached to a plurality of lead-acid batteries 1 connected in series and / or parallel, respectively, and a control unit (management unit) 10 capable of wirelessly connecting to the plurality of sensor units 20.

[0012] Here, a plurality of lead-acid batteries 1 connected in series may be referred to as a bank, and a plurality of banks connected in parallel may be referred to as a domain.

[0013] The control unit 10 and the multiple sensor units 20 may be installed in a battery panel that houses multiple lead-acid batteries to be monitored. For example, the control unit 10 is attached to the inside of the opening / closing cover of the battery panel. The multiple sensor units 20 are installed on each of the multiple lead-acid batteries 1 arranged in the battery panel.

[0014] The control unit 10 has a web server function and may receive access from a network-connected computer (PC) or a terminal such as a tablet.

[0015] 2 is a block diagram showing the configuration of the control unit 10. The control unit 10 includes a control unit 100, a storage unit 110, a display unit 30, an operation unit 40, a first communication unit 51, a second communication unit 52, and a third communication unit 53.

[0016] The control unit 100 has a processor, and controls the first communication unit 51 , the second communication unit 52 , and the third communication unit 53 based on a program stored in the storage unit 110 .

[0017] The storage unit 110 uses a nonvolatile memory. The storage unit 110 stores programs in advance. The storage unit 110 stores storage battery information acquired by the control unit 100.

[0018] The display unit 30 is, for example, a liquid crystal panel. The operation unit 40 is a touch panel built into the liquid crystal panel. The operation unit 40 may include physical buttons.

[0019] The first communication unit 51 is a wireless communication module that realizes wireless communication connection with the sensor unit 20. The control unit 10 is communicatively connected to a plurality of sensor units 20 via the first communication unit 51. The first communication unit 51 realizes communication via BLE. The second communication unit 52 is a connection module for connecting to the network of the customer (a customer who owns a power storage system such as a backup power supply using a lead-acid battery 1) shown in FIG. 1, and is, for example, a network card compatible with a wired LAN. The third communication unit 53 is a communication module that enables communication connection with a network-connected computer (PC) or tablet terminal of a maintenance technician. The third communication unit 53 is, for example, a USB (Universal Serial Bus). The third communication unit 53 may realize communication with the tablet terminal of the maintenance technician via wireless LAN.

[0020] 3 is a schematic diagram showing communication between the control unit 10 and the sensor units 20. Messages broadcast from the control unit 10 to multiple sensor units 20 include identification information of the specific sensor unit 20. The message may include a MAC address storage section and a message body. The MAC address storage section may store identification information of a particular sensor unit 20.

[0021] The control unit 10 has a web server function and creates screen data for screen display including an icon representing the overall state of the plurality of lead-acid batteries 1.

[0022] 4 shows an example of a remote monitoring screen displayed on a web browser terminal network-connected to the control unit 10. The remote monitoring screen includes an icon for the overall status, an icon for the storage battery voltage state, and an icon for the storage battery internal resistance state.

[0023] As the overall status icon, in addition to an icon indicating "normal," an icon indicating "caution" or an icon indicating "warning" may be prepared. Similarly, icons indicating "caution" or "warning" may be prepared for the icons of the battery voltage state and the battery internal resistance state.

[0024] In the above-mentioned lead-acid battery monitoring device, a message broadcast from the control unit 10 to multiple sensor units 20 includes identification information of a specific sensor unit 20, and communication between the control unit 10 and the specific sensor unit 20 is established using the identification information. Therefore, even in a case where hundreds of sensor units 20 are provided in association with hundreds of lead-acid batteries 1, such as in a power storage system having a group of storage batteries in the form of a domain including multiple banks, the control unit 10 can reliably acquire monitoring data sequentially from the sensor units 20.

[0025] In the lead-acid battery monitoring device, the sensor unit 20 and the control unit 10 are installed on the same battery panel. It is relatively easy to install (retrofit) this lead-acid battery monitoring device on an existing battery panel that does not have a monitoring device.

[0026] The sensor unit 20 wirelessly transmits monitoring data of the voltage, internal resistance, and temperature of the lead-acid battery 1 to which the sensor unit 20 is connected to the control unit 10. Therefore, the state of health (SOH) of the lead-acid battery 1 can be monitored. As will be described later, each sensor unit 20 measures the temperature of the lead-acid battery 1 to which it is attached more frequently than the internal resistance. Each sensor unit 20 performs a first monitoring operation of measuring the internal resistance and temperature of the lead-acid battery 1 and wirelessly transmitting the results to the control unit 10, and a second monitoring operation of measuring the temperature of the lead-acid battery 1 and wirelessly transmitting the results to the control unit 10.

[0027] The control unit 10 may compare the monitoring data (numerical data) of the plurality of lead-acid batteries 1 with thresholds or perform statistical processing to determine the overall state. The lead-acid batteries 1 can be remotely monitored using a web browser on a terminal connected to the control unit 10 via LAN. Icons that represent the overall status of the multiple lead-acid batteries 1 make it easy to understand the status of the power storage system.

[0028] 5 is a flowchart showing an example of a processing procedure in the control unit 10. The control unit 10 executes the following processing on a bank-by-bank basis at a predetermined timing. The control unit 10 executes the processing for all banks in order. The control unit 10 stores in its built-in memory the timing for executing the following processing and the identification information of the sensor unit 20 to be connected.

[0029] The control unit 10 selects one piece of identification information of the sensor unit 20 (step S201). The control unit 10 transmits a connection request message including the selected identification information by BLE (step S202), and determines whether a communication connection (pairing) with the sensor unit 20 of the selected identification information has been established (step S203).

[0030] If it is determined in step S203 that a communication connection has been established (S203: YES), the control unit 10 sends a measurement request to the sensor unit 20 with which it is connected (step S204), and determines whether or not it has received the monitoring data obtained by measuring in response to the measurement request (step S205).

[0031] If it is determined that the monitoring data has been received (S205: YES), the control unit 10 sends a sleep instruction to the sensor unit 20 with which it is connected for communication (step S206), disconnects the communication connection (step S207), and proceeds to the next step S208.

[0032] The control unit 10 determines whether or not the identification information of all the sensor units 20 included in the target bank has been selected (step S208). If it is determined that all the sensor units 20 have not been selected (S208: NO), the control unit 10 returns the process to step S201 and selects the identification information of the next sensor unit 20.

[0033] If it is determined that all the banks have been selected (S208: YES), the control unit 10 ends the processing for the bank.

[0034] If it is determined in step S203 that a communication connection has not been established (S203: NO), the control unit 10 returns the process to step S203 and waits. The control unit 10 makes a predetermined number of attempts within a predetermined waiting time, and if communication cannot be established, the control unit 10 proceeds to step S207.

[0035] If it is determined in step S205 that the signal cannot be received (S205: NO), the control unit 10 returns the process to step S205 and waits. The control unit 10 makes a predetermined number of attempts within a predetermined waiting time, and if the control unit 10 is unable to receive data, the process proceeds to step S207.

[0036] 6 is a flowchart showing an example of a processing procedure (first monitoring operation) in the sensor unit 20. The sensor unit 20 intermittently wakes up the BLE communication device from a sleep state, for example, every two or three seconds (step S301), and determines whether or not a connection request to itself has been received (step S302).

[0037] If it is determined that the connection request has not been received (S302: NO), the sensor unit 20 transitions to the sleep state again (step S303) and ends the process.

[0038] If it is determined in step S302 that the connection request has been received (S302: YES), the sensor unit 20 starts up the entire system (step S304) and determines whether or not a measurement request has been received (step S305). If it is determined that a measurement request has been received (S305: YES), the sensor unit 20 measures monitoring data of the voltage, internal resistance, and temperature of the lead-acid battery to which the sensor unit 20 is attached (step S306). The sensor unit 20 transmits the monitoring data obtained by the measurement to the control unit 10 as a response to the measurement request (step S307).

[0039] The sensor unit 20 determines whether or not a sleep instruction has been received (step S308), and if it is determined that a sleep instruction has been received, transitions to a sleep state (step S303) and ends the process.

[0040] If the sensor unit 20 determines in step S305 that it has not received the measurement request (S305: NO), it returns the process to step S305 and waits. If the sensor unit 20 has not received the measurement request after making a predetermined number of attempts within a predetermined waiting time, it proceeds to step S303.

[0041] If the sensor unit 20 determines in step S308 that it has not received the sleep instruction (S308: NO), it returns the process to step S308 and waits. If the sensor unit 20 has not received the sleep instruction after making a predetermined number of attempts within a predetermined waiting time, it proceeds to step S303.

[0042] In summary, the lead-acid battery monitoring device shown in FIGS. 5 and 6 performs the following operations. The control unit 10 sequentially selects the identification information of multiple sensor units 20 stored in advance, and sends a connection request message including the identification information of the selected sensor unit 20 to the multiple sensor units 20 in order to establish communication with the selected sensor unit 20, and sends a measurement request for monitoring data to the sensor unit 20 with which communication has been established. Each of the multiple sensor units 20 intermittently wakes up from a sleep state for wireless communication with the control unit 10, determines whether or not it has received a connection request message including its own device's identification information, and transitions to a sleep state if it has not received the connection request message, and if it has received a connection request message, measures monitoring data of the lead-acid battery to which that sensor unit 20 is connected in response to receiving the measurement request, wirelessly transmits the measured monitoring data to the control unit 10, and then transitions to the sleep state. When a sleep instruction is received from the control unit 10 or the communication connection with the control unit 10 is disconnected, the sensor unit 20 transitions to the sleep state.

[0043] FIG. 7 is a schematic diagram showing the communication procedure during the first monitoring operation. The first monitoring operation is performed, for example, once a day. The control unit 10 executes the procedure shown in the flowchart of FIG. 5, and the sensor unit 20 executes the procedure shown in the flowchart of FIG. 6 accordingly, showing the startup time of the sensor unit 20. As shown in FIG. 7, the sensor unit 20 intermittently determines whether or not a connection request has been received by the BLE communication device. Only when a connection request has been received, does the sensor unit 20 measure monitoring data (voltage, internal resistance, temperature) of the lead-acid battery 1 to which the sensor unit is attached and wirelessly transmit the measured monitoring data to the control unit 10. While the control unit 10 sequentially performs the first monitoring operation with multiple sensor units 20, it does not perform the second monitoring operation described below.

[0044] As described above, the lead-acid battery monitoring device executes the first monitoring operation, for example, once a day, to acquire the voltage, internal resistance, and temperature from each lead-acid battery 1. Alternatively, the first monitoring operation may acquire the internal resistance and temperature from each lead-acid battery 1. Of these monitoring data, the temperature in particular has a significant impact on the deterioration and lifespan of the lead-acid battery 1.

[0045] The temperature of the lead-acid battery 1 often fluctuates throughout the day due to the influence of the ambient temperature, etc. It is expected that the estimation accuracy will be higher if the average temperature for the day is calculated from temperatures measured multiple times a day and the deterioration of each lead-acid battery 1 is estimated based on the average temperature, rather than estimating the deterioration of each lead-acid battery 1 based on the temperature measured once a day.

[0046] On the other hand, measuring the internal resistance requires a weak discharge from each lead-acid battery 1, and if the first monitoring operation is performed multiple times a day to measure the internal resistance along with the temperature, each lead-acid battery 1 will be discharged multiple times a day. When the power storage system is used as a backup power source, the multiple lead-acid batteries 1 are constantly charged (e.g., float charged) from the power grid, so after a weak discharge is performed to measure the internal resistance, the lead-acid batteries 1 are charged. Although it is a weak discharge, because discharge and charging occur (cycles), it is expected that increasing the number of times the internal resistance is measured will accelerate the deterioration of the lead-acid batteries 1.

[0047] FIG. 8 shows a lead-acid battery monitoring device performing a first monitoring operation, which measures and acquires the voltage, internal resistance, and temperature of each lead-acid battery 1, and a second monitoring operation, which measures and acquires only the temperature of each lead-acid battery 1. In FIG. 8, the first monitoring operation is performed once a day, and the second monitoring operation is performed three times a day at a timing different from the timing of the first monitoring operation. The lead-acid battery monitoring device of this embodiment performs the second monitoring operation more times than the first monitoring operation, at a timing different from the timing of the first monitoring operation. After performing the first monitoring operation once, the lead-acid battery monitoring device may perform the second monitoring operation multiple times in succession, with time intervals between each. For example, the lead-acid battery monitoring device may perform the first monitoring operation once at 1:00 AM, and then perform the second monitoring operation three times every six hours. The order of performing the first and second monitoring operations is not limited to the example shown in FIG. 8. The lead-acid battery monitoring device may perform the first monitoring operation once, and then perform the second monitoring operation twice in succession with a time interval therebetween, or may perform the second monitoring operation four or more times in succession with a time interval therebetween.

[0048] As shown in Fig. 9, the lead-acid battery monitoring device may measure and acquire voltage and temperature in the second monitoring operation. That is, in the second monitoring operation, monitoring data of the lead-acid battery 1 other than internal resistance is acquired. The sensor unit 20 can transition to the sleep state earlier when only temperature is measured in the second monitoring operation as in Fig. 8 than in the case of Fig. 9. Although FIGS. 8 and 9 show an example in which the voltage, internal resistance, and temperature are acquired in the first monitoring operation, alternatively, the internal resistance and temperature may be acquired in the first monitoring operation.

[0049] With the above configuration, it is possible to reduce the frequency of measurements of the internal resistance that requires discharging the lead-acid battery 1, while increasing the frequency of measurements of the temperature that has a significant impact on the deterioration and lifespan of the lead-acid battery 1, thereby making it possible to grasp the state of the lead-acid battery 1 with high accuracy.

[0050] When monitoring a large-scale energy storage system consisting of hundreds of lead-acid batteries 1, it takes a considerable amount of time for the control unit 10 to connect to each sensor unit 20 sequentially via wireless communication and acquire monitoring data from all of the lead-acid batteries 1. The environmental temperature at the time the temperature of the first lead-acid battery 1 is measured may be different from the environmental temperature at the time the temperature of the last lead-acid battery 1 is measured. If temperature measurements are taken once a day, a lead-acid battery that has a high measured temperature may be erroneously determined to be rapidly deteriorating. In contrast, it is expected that the accuracy of the estimation will be improved by taking temperature measurements multiple times a day and estimating the deterioration using the average temperature of each lead-acid battery 1 on that day.

[0051] Deterioration estimation using the average temperature may be performed by the control unit 10. Alternatively, monitoring data including the average temperature of each lead-acid battery 1 may be transmitted from the control unit 10 to a maintenance worker's terminal via the third communication unit 53 (see FIG. 2), and deterioration estimation may be performed by the maintenance worker's terminal. Furthermore, monitoring data may be transmitted from the maintenance worker's terminal to a remote information processing device (such as a remote monitoring server) connected to a network, and deterioration estimation may be performed by the information processing device.

[0052] Although an example has been described in which the average temperature of each lead-acid battery 1 over a predetermined period (one day) is calculated and used to estimate deterioration, the predetermined period is not limited to one day. The average temperature may be calculated by the control unit 10, or by a maintenance worker terminal or a remote information processing device. The average temperature may be calculated by the control unit 10, and the average temperature and the measured value for each time may be stored as log data in the storage unit 110 (see FIG. 2). In this way, in addition to the change in the average temperature, the change in temperature on a daily basis (a predetermined period of time) may also be confirmed and understood.

[0053] An example has been described in which each of the plurality of sensor units 20 performs a first monitoring operation in which the sensor units 20 measure the internal resistance and temperature of the lead-acid battery 1 and wirelessly transmit the results to the control unit 10, and a second monitoring operation in which the sensor units 20 measure the temperature of the lead-acid battery 1 and wirelessly transmit the results to the control unit 10. The timing of measuring each monitoring parameter is not limited to the example of the embodiment. As mentioned above, measuring the internal resistance requires a weak discharge from each lead-acid battery 1. In a bank in which multiple lead-acid batteries 1 are connected in series, when measuring the internal resistance of one lead-acid battery 1, the voltage of the other lead-acid batteries 1 may fluctuate (for example, the voltage may increase). This voltage fluctuation is a phenomenon that occurs due to the measurement of the internal resistance of one lead-acid battery 1, and does not indicate that the state of the other lead-acid batteries 1 has actually changed. This voltage fluctuation usually disappears after a while has passed. To avoid the sensor unit 20 measuring and transmitting to the control unit 10 the voltage that has fluctuated due to the internal resistance measurement, the sensor unit 20 may first measure a monitoring parameter other than the internal resistance and then measure the internal resistance. That is, the sensor unit 20 may measure the voltage and temperature of the lead-acid battery 1 and transmit them to the control unit 10, and then measure the internal resistance of the lead-acid battery 1 and transmit them to the control unit 10. The measurement timing of each monitoring parameter can be set arbitrarily as long as the control unit 10 can receive, as monitoring data for each lead-acid battery 1, temperatures measured at more measurement points than the internal resistance. [Explanation of symbols]

[0054] 1 lead acid battery 10 Control unit (management unit) 20 Sensor unit (monitoring unit)

Claims

1. a plurality of monitoring units attached to a plurality of lead-acid batteries connected in series and / or parallel to measure monitoring data; a management unit that sequentially connects wirelessly to the plurality of monitoring units, a first monitoring operation in which the management unit receives monitoring data including an internal resistance and a temperature of each lead-acid battery from the plurality of monitoring units in sequence; a second monitoring operation in which the management unit receives monitoring data including the temperature of each lead-acid battery from the plurality of monitoring units in sequence; the management unit creates a remote monitoring screen that indicates whether each lead-acid battery is in a normal, caution, or warning state based on the monitoring data, even if the battery is normal; The management unit outputs the remote monitoring screen to a terminal connected via a local network.

2. 2. The lead-acid battery monitoring device according to claim 1, wherein the remote monitoring screen displays the temperature or internal resistance of each lead-acid battery.

3. 3. The lead-acid battery monitoring device according to claim 1, wherein the remote monitoring screen displays a transition of the temperature or internal resistance of each lead-acid battery.

4. 3. The lead-acid battery monitoring device according to claim 1, wherein the remote monitoring screen displays that the status of each lead-acid battery is normal.

5. 3. The lead-acid battery monitoring device according to claim 1, wherein the management unit causes the terminal to display the remote monitoring screen in response to a request from the terminal.

6. 6. The lead-acid battery monitoring device according to claim 5, wherein the terminal is a maintenance personnel terminal for the lead-acid battery.

7. 3. The lead-acid battery monitoring device according to claim 1, wherein each of the plurality of monitoring units transitions to a sleep state after transmitting the monitoring data to the management unit.

8. 3. The lead-acid battery monitoring device according to claim 1, wherein the monitoring data received by the management unit is stored and processed by another device that is directly or indirectly connected to the management unit for communication.

9. The management unit sequentially connects wirelessly to a plurality of monitoring units attached to a plurality of lead-acid batteries connected in series and / or parallel; performing a first monitoring operation in which the management unit receives monitoring data including an internal resistance and a temperature of each lead-acid battery from the plurality of monitoring units in sequence; performing a second monitoring operation in which the management unit receives monitoring data including the temperature of each lead-acid battery from the plurality of monitoring units in sequence; the management unit creates a remote monitoring screen that indicates whether each lead-acid battery is in a normal, caution, or warning state based on the monitoring data, even if the battery is normal; The management unit outputs the remote monitoring screen to a terminal connected via a local network.

10. the management unit connects communication with maintenance personnel terminals of the plurality of lead-acid batteries via a communication medium different from a communication medium with the monitoring unit; 10. The lead-acid battery monitoring method according to claim 9, wherein the management unit displays the remote monitoring screen on a maintenance personnel terminal in response to a request from the maintenance personnel terminal.

11. The lead-acid battery monitoring method according to claim 10 , wherein the maintenance staff terminal acquires the monitoring data received by the management unit and executes arithmetic processing.

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