Device apparatus and energy storage system

Abstract

To detect abnormalities in connection of slave devices or abnormalities in a communication circuit by detecting the number of serial connections in the slave devices and comparing it with a set value in a communication form in which a master device and the slave devices are daisy-chained.SOLUTION: A device apparatus includes one master device 65 and a plurality of slave devices 70, and the one master device 65 and the plurality of slave devices 70 are daisy-chained together via a communication line L. The master device 65 assigns consecutive device addresses to all devices, and then performs response confirmation for each of the plurality of slave devices 70 through communication via the communication line L. The master device 65 detects the number Q of serial connections of the slave devices 70 based on the device addresses of slave devices 70 whose responses have been successfully confirmed, and compares the detected number of serial connections with a set value Q.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to daisy-chained devices. [Background technology]

[0002] The introduction of energy storage systems is being promoted to achieve efficient energy management. When the demand for electricity is lower than the supply, the energy storage system charges a storage bank with surplus electricity, and when the demand for electricity exceeds the supply, the system discharges the storage bank to make up for the power shortage. Patent Document 1 is a document disclosing technology related to energy storage systems. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-65595 Summary of the Invention [Problem to be solved by the invention]

[0004] A typical energy storage bank is configured by connecting multiple energy storage modules (units of multiple energy storage cells) in series, with a module monitoring device monitoring the status of the energy storage modules and a bank monitoring device monitoring the entire energy storage bank.

[0005] In a communication format in which a bank monitoring device (master device) and a module monitoring device (slave device) are daisy-chained, there was no established technology to detect connection or communication abnormalities in the module monitoring device. This issue was not limited to monitoring devices for power storage banks, but was present in all daisy-chained devices.

[0006] An object of the present invention is to detect connection abnormalities or communication abnormalities in slave devices by detecting the serial number of slave devices and comparing it with a set value in a communication configuration in which a master device and slave devices are daisy-chain connected. [Means for solving the problem]

[0007] A device apparatus according to one embodiment of the present invention includes one master device and a plurality of slave devices, and the one master device and the plurality of slave devices are daisy-chain connected by a communication line.

[0008] The master device assigns consecutive device addresses to all devices, and then communicates via the communication line to confirm the response of each of the slave devices. The master device detects the serial number of the slave devices based on the device addresses of the slave devices whose responses have been successfully confirmed, and compares the detected serial number with a set value. [Effects of the Invention]

[0009] In a communication configuration in which a master device and slave devices are daisy-chained, this technology detects the serial number of the slave device and compares it with a set value, making it possible to detect connection or communication abnormalities in the slave device. [Brief explanation of the drawings]

[0010] [Figure 1] Energy storage system block diagram [Figure 2] Battery panel block diagram [Figure 3] Perspective view of the energy storage module [Figure 4] A diagram showing the communication method between the bank monitor and the module monitor. [Figure 5] Diagram showing the IC startup sequence [Figure 6] A diagram showing the device addresses of each device [Figure 7] Abnormality determination sequence [Figure 8] A diagram showing the device addresses of each device [Figure 9] A diagram showing the device addresses of each device DETAILED DESCRIPTION OF THE INVENTION

[0011] (Outline of this embodiment) (1) A device apparatus according to one embodiment of the present invention includes one master device and multiple slave devices, and the master device and multiple slave devices are daisy-chained together by a communication line.

[0012] The master device assigns consecutive device addresses to all devices, and then confirms the response of each of the slave devices through communication via the communication line.The master device detects the serial number of the slave device based on the device address of the slave device whose response has been confirmed successfully, and compares the detected serial number with a set value.The master device is a device that controls or manages the slave devices.In the device apparatus described in (1), any configuration other than the above is optional and may be used.

[0013] The operation and effect of the device apparatus described in (1) will be explained. Since the device addresses assigned to all devices are consecutive, by referencing the device addresses of the slave devices whose responses have been successfully confirmed, it is possible to determine from which numbers the responses have been confirmed, and from which numbers onwards or before which the responses have not been confirmed. Therefore, it is possible to find the serial number of the slave devices from the device addresses of the slave devices whose responses have been successfully confirmed.

[0014] This method allows the master device to automatically detect the serial number of slave devices through software processing. Furthermore, by comparing the serial number with a set value, the comparison result can detect the presence or absence of connection abnormalities or communication circuit failures of the slave devices. For example, by detecting the serial number of slave devices and comparing it with a set value when the device is started, the comparison result can detect the presence or absence of connection abnormalities or communication abnormalities (circuit failures), thereby preventing the device from reaching an unsafe event.

[0015] (2) In the device apparatus described in (1), the master device may set a total number of all devices connected in a daisy chain based on the maximum serial number of the slave devices. The master device may assign device addresses, which are the total number of devices minus one, to all devices connected in a daisy chain, in order from the master device to the top device of the slave devices. The master device may perform response confirmation on the slave devices connected in the daisy chain in ascending order of device addresses. The master device may calculate the serial number of the slave devices by subtracting the device address of the slave device that first successfully confirmed the response from the total number of devices. In the device apparatus described in (2), any configuration other than the above is optional and may be used.

[0016] The device apparatus described in (2) can calculate the serial number of slave devices by subtracting the device address of the slave device that first succeeded in confirming the response from the total number of devices.

[0017] (3) In the device apparatus described in (1) or (2), the total number of devices may be a value obtained by adding 2 to the maximum number of serial connections of the slave devices. In the device apparatus described in (3), any configuration other than the above is optional and may be any configuration.

[0018] The device apparatus described in (3) can detect that the number of slave devices connected is greater than the set value. For example, if the set value of the number of serial slave devices is 3, it can detect that four or more slave devices are connected.

[0019] (4) The device according to any one of (1) to (3) may be used for monitoring a power storage bank. The power storage bank may include a plurality of power storage modules. The slave device may be a monitoring device for the power storage modules. The master device may be a monitoring device for the power storage bank. This configuration can contribute to improving the reliability of the power storage bank monitoring system by detecting connection abnormalities.

[0020] (5) An energy storage system includes a PCS panel that houses a power conversion unit and a battery panel that houses a power storage bank connected to the power conversion unit via a power line. The power storage bank includes a plurality of power storage modules connected in series, a module monitoring device that monitors the power storage modules, and a bank monitoring device. The bank monitoring device and the plurality of module monitoring devices are daisy-chained via a communication line, and the bank monitoring device assigns consecutive device addresses to all monitoring devices and then confirms responses from each of the plurality of module monitoring devices via the communication line. The bank monitoring device detects the number of series of the module monitoring devices based on the device address of the module monitoring device that successfully confirmed the response and compares the detected number of series with a set value. In the energy storage system described in (5), any configuration other than the above is optional and may be used.

[0021] The number of series connections in energy storage modules can vary from project to project. If the number of series connections differs from the actual number due to incorrect or defective harness connections or communication abnormalities (circuit failures) during the construction (assembly) of the energy storage system and cannot be detected, it could lead to an unsafe event at the energy storage bank. By applying this technology, it is possible to detect the number of series connections in the module monitoring device. By comparing the number of series connections with the installed value, it is possible to detect the connection status (incorrect or defective harness connections, etc.) and communication abnormalities (circuit failures) of the module monitoring device. This makes it possible to prevent the energy storage bank from reaching an unsafe event.

[0022] (6) In the energy storage system described in (5), the bank monitoring device may detect the number of series of the module monitoring devices and compare it with a set value when the energy storage system is first started up. In the energy storage system described in (6), any configuration other than the above is optional and any configuration may be used.

[0023] Energy storage systems require the assembly of complex and numerous wiring connections during on-site construction. In particular, when a storage bank is composed of multiple energy storage modules and a module monitoring device is installed for each energy storage module, the numerous wiring connections make harness connection errors and harness defects more likely to occur. When such errors or defects occur, it takes time to determine the cause, delaying the construction of the energy storage system and preventing successful initial startup, directly leading to operational delays. Using this technology, the number of series connections in the module monitoring device is detected and compared with a set value during the initial startup of the energy storage system. From the comparison results, the module monitoring device's connection status (harness connection errors, harness defects, etc.) and communication abnormalities (circuit failures) can be determined. This allows for smooth initial startup of the energy storage system, contributing to early operation.

[0024] <Embodiment 1> 1. Description of Energy Storage System 10 Figure 1 is a block diagram of an energy storage system 10. The energy storage system 10 is a system that is connected to a power grid 1 and adjusts the supply and demand of electricity. The power grid 1 may be that of a power utility company, or it may be an independent power grid that consists of the stand-alone operation output of a large power conditioner.

[0025] The energy storage system 10 includes a battery panel 20 that stores energy, a PCS panel 30, and a remote monitoring panel 50. PCS is an abbreviation for Power Conditioning System.

[0026] The PCS panel 30 includes power conversion units 40A to 40C, a control unit 45, and a housing 31 that houses them. The power conversion units 40A to 40C are bidirectional power converters capable of reverse conversion (DC to AC) and forward conversion (AC to DC). The power conversion units 40A to 40C are connected to the power grid 1 via an interconnection switch 43.

[0027] The inverse conversion operation (DC to AC) of the power conversion units 40A to 40C allows the battery panel 20 to be discharged and AC power to be supplied to the power grid 1. In addition, the forward conversion operation (AC to DC) of the power conversion units 40A to 40C allows the battery panel 20 to be charged with AC power from the power grid 1.

[0028] In this embodiment, the capacity of the PCS board 30 is ensured by providing a plurality of three power conversion units 40A to 40C in parallel.

[0029] The control unit 45 includes, for example, a CPU (Central Processing Unit) and a memory for storing various data. The control unit 45 controls the power conversion units 40A to 40C in response to commands from a higher-level system such as an EMS (Energy Management System) and adjusts the supply and demand of power.

[0030] Specifically, when the demand for electricity is lower than the supply, the excess electricity is used to charge the battery panel 20 of the energy storage system 10, and when the demand for electricity exceeds the supply, the power shortage is made up by discharging the battery panel 20 of the energy storage system 10.

[0031] By exchanging power with the power grid 1 and adjusting supply and demand, it is possible to improve the efficiency of energy use and contribute to energy conservation.

[0032] The remote monitoring panel 50 is equipped with a communication board 55 for wireless communication with the remote monitoring device 100. The remote monitoring device 100 remotely monitors the state (SOC and temperature) of the battery panel 20 by communication via the remote monitoring panel 50. The remote monitoring panel 50 also has a communication function with a higher-level system, and commands from the higher-level system are notified to the control unit 45 of the PCS panel 30 via the remote monitoring panel 50.

[0033] 2. Configuration of the battery panel 20 2 is a block diagram of the battery panel 20. The battery panel 20 is composed of one or more power storage banks 21, a thermistor 22 that detects the temperature of the battery panel 20, a panel air conditioner 23 that controls the temperature of the battery panel 20, a fire detection system 24, a battery panel monitoring unit 25, and a housing 20A that houses these components.

[0034] The battery panel monitoring unit 25 includes a control device 26, a memory unit 27, a display unit 28, and a DC power supply unit 29. The battery panel monitoring unit 25 collects information from within the battery panel and communicates with the PCS panel 30 and the remote monitoring device 100.

[0035] The power storage bank 21 is composed of a plurality of power storage modules 60 connected in series, a current sensor 63, a fuse 64, a relay switch, a bank monitoring device 65, and a plurality of module monitoring devices 70. The current sensor 63 measures the current of the power storage bank 21, and the relay switch cuts off the current of the power storage bank 21.

[0036] 3, the power storage module 60 is a unit formed by fixing a plurality of power storage cells 61 connected in series to a frame 62. Various types of cells can be used as the power storage cells 61, such as non-aqueous electrolyte secondary battery cells such as lithium ion secondary batteries, capacitors, NAS battery cells, and redox flow battery cells, as long as they are capable of storing electricity (capable of repeated charging and discharging).

[0037] When the energy storage system 10 has multiple battery panels 20, the battery types of the battery panels 20 may be the same or different. For example, all the battery panels 20 may be made of lithium-ion secondary batteries, or a combination of battery panels 20 made of lithium-ion secondary batteries and battery panels 20 made of NAS may be used.

[0038] A module monitoring device 70 is provided for each power storage module 60. The module monitoring device 70 monitors the temperature of the power storage module 60 and the cell voltage of each power storage cell 61.

[0039] The bank monitoring device 65 performs integrated management of the number of series connections and communication status of the module monitoring devices 70, and monitors the power storage bank 21. For example, it monitors the current of the power storage modules 60 based on the measurement value of the current sensor 63, and monitors the temperature of each power storage module 60 and the cell voltage of each power storage cell 61 through communication with the module monitoring device 70.

[0040] The power storage bank 21 is connected to a power line (main circuit) L0 via a fuse 64 and a relay SW. The power storage bank 21 may be configured as a single bank or multiple banks. Fig. 2 shows a configuration of three banks.

[0041] 3. Communication method and communication sequence 4 is a diagram showing a communication system between the bank monitor 65 and the module monitor 70. The bank monitor 65 includes a CPU 66, a communication IC 67, a pulse transformer 68, and a memory unit 69.

[0042] The module monitoring device 70 includes a pulse transformer 71, a monitoring IC 75, and an EEPROM 76. The monitoring IC 75 has a monitoring function and a communication function for the energy storage cells 61. The EEPROM 76 stores information such as the serial number of the monitoring IC 75, the number of cells in the energy storage module 60, and the type of the cells 61.

[0043] The bank monitoring device 65 and the multiple module monitoring devices 70 are daisy-chained via a communication line L. A daisy-chain connection is a form in which multiple devices are connected in a daisy-chain fashion, and is also called a cascade connection. FIG. 4 shows an example in which three module monitoring devices 70 are daisy-chained (number of series = 3). The number of connections is just an example, and may be any number other than 3.

[0044] The bank monitoring device 65 communicates with each module monitoring device 70 via a bucket brigade network (specifically, insulated two-wire differential SPI communication). SPI is an abbreviation for Serial Peripheral Interface.

[0045] In this communication method, the CPU 66 of the bank monitoring device 65 communicates directly with the monitoring IC 75 of the module monitoring device 70 via the communication IC 67, pulse transformer 68, and pulse transformer 71. This eliminates the need for a CPU or its peripheral circuits (such as a power supply circuit or reset circuit for the CPU) in the module monitoring device 70, thereby reducing the cost of the module monitoring device 70. Furthermore, the use of pulse transformers 68 and 71, which essentially have an infinite lifespan, improves long-term reliability compared to using photocouplers, which have a finite lifespan. Electrical isolation between the bank monitoring device 65 and the module monitoring device 70 ensures user safety (electric shock protection). In particular, in this example, the use of two pulse transformers 68 and 71 allows the remote monitoring panel 50 to be double-insulated against the battery voltage of the power storage bank 21.

[0046] 4.Starting up the communication IC and assigning a device address 5 shows the startup flow of the communication ICs 67, 75A, 75B, and 75C of the power storage bank 21. The vertical axis represents time. The K1 box represents the startup process of the communication ICs, and the K2 box represents the process of assigning device addresses to the communication ICs.

[0047] The communication ICs start with a start command sent from the CPU 66 to the communication IC 67, and then start commands are sent in sequence between the ICs, thereby starting up the ICs 75A, 75B, and 75C in sequence.

[0048] Specifically, the CPU 66 first starts the communication IC 67 in response to a start-up instruction. After that, the CPU 66 again sends a start-up command to the communication IC 67 to start the monitoring IC, causing the communication IC 67 to start the second-stage monitoring IC 75A. Similarly, the second-stage monitoring IC 75A starts the third-stage monitoring IC 75B, and the third-stage monitoring IC 75B starts the fourth-stage monitoring IC 75C.

[0049] The device addresses are assigned after all ICs 67, 75A to 75C are started up. Specifically, first, the CPU 66 sets a device address (for example, the total number of communication ICs) for the communication IC 67. The communication IC 67 subtracts 1 from the device address and transmits the resulting device address to the next monitoring IC 75A and assigns it to the next monitoring IC 75A.

[0050] In this way, an IC can assign consecutive device addresses by subtracting 1 from the device address and sending it to the next IC.

[0051] In the example of FIG. 6, the total number of communication ICs is four, and device addresses 4, 3, 2, and 1 can be assigned to the communication IC 67, the monitoring IC 75A, the monitoring IC 75B, and the monitoring IC 75C in that order.

[0052] The device address of the monitoring IC 75C is determined after sending an ACK to the monitoring IC 75B. The other monitoring ICs, 75B, 75A, and communication IC 67, are determined after receiving an ACK from the monitoring ICs 75C, 75B, and 75A, or after the DAISY communication times out. The ACK is a confirmation signal that indicates that communication has been completed successfully.

[0053] In the following description, the bank monitoring device 65 is referred to as a master device, and the module monitoring devices 70A to 70C are referred to as slave devices, as shown in Fig. 6. Of the slave devices 70A to 70C, the one closer to the master device 65 in the communication transmission direction is referred to as the lower tier, the one farther away is referred to as the upper tier, and the top tier is referred to as the top device.

[0054] 2. Number of serial connections Q for 70 slave devices The number Q of series connections of the slave devices 70 may differ depending on the scale and specifications of the energy storage system 10. When assembling the battery panel, if the number Q of series connections of the slave devices 70 differs from the expected design value due to a harness connection error, a communication circuit failure, or the like, and this cannot be detected, it may lead to an unsafe event.

[0055] In this embodiment, when the communication IC of the power storage bank 21 is started up (including the initial start-up after on-site installation of the energy storage system, start-up after power-on, start-up by reset or restart, etc.), the abnormality determination sequence shown in FIG. 7 is executed to determine whether the connection status of the slave device 70 is good or bad.

[0056] To execute the abnormality determination sequence shown in FIG. 7, the master device (CPU 66) stores an execution program for the abnormality detection sequence and the following information in the storage unit 69.

[0057] Design value of the number of serial slave devices Q - Maximum number of serial slave devices (70) Qmax (maximum number of serial connections possible based on product specifications, etc.)

[0058] The abnormality determination sequence shown in FIG. 7 is made up of the processes of S10 to S60. <Device address assignment> When the abnormality determination sequence starts, the master device (CPU 66) writes the total number of devices N into the register 67A of the communication IC 67 in S10.

[0059] N=(Qmax+1)+1 (1) Qmax is the maximum serial number of the slave device 70. (Qmax+1) indicates the maximum serial number of all devices, including the master device 65, plus the maximum serial number of the slave device 70.

[0060] The reason why 1 is added to the maximum number of serial connections (Qmax+1) of all devices on the right side of equation (1) is to determine if the number of serial connections Q of the slave device 70 exceeds the maximum number of serial connections Qmax.

[0061] The master device 65 assigns consecutive device addresses to all communication ICs when the ICs are started up. Specifically, addresses obtained by subtracting 1 from the total number of devices N are assigned to each device from the master device 65 to the top device 70 in the uppermost row. The procedure for assigning and determining device addresses is as described with reference to FIGS. 5 and 6.

[0062] <Response confirmation> After the device addresses are determined, the process proceeds to S20, where the master device 65 performs response confirmation on each slave device 70 in order, starting with device address 1. The response confirmation determines whether communication is normal, and is confirmed by checking whether an ACK is returned in response to the transmission of the response confirmation signal. When response confirmation has been completed for all slave devices 70 to which addresses have been assigned, the process proceeds to S30.

[0063] <Calculating the number of series Q> In S30, the master device 65 detects the serial number Q of the slave devices 70 by subtracting the device address with which communication was first established in S20 from the total number N of devices set in S10.

[0064] 8, if the total number of devices N=27 (the maximum number of serial slave devices 70 Qmax=25) and the actual number of serial slave devices 70 is 4, communication is not possible for device addresses 1 to 22, but communication is possible from device address 23 onwards. Therefore, the number of serial slave devices 70 can be calculated as Q=27-23, which is 4.

[0065] After detecting the serial number Q, the master device 65 shuts down and restarts the monitoring IC 75 of the slave device 70. Then, the master device 65 assigns a new device address with the serial number Q calculated in S30 (see FIG. 9). Even if the serial number Q of the slave device 70 changes, the serial number Q of the slave device 70 can be calculated using the above method.

[0066] <Connection status determination> Thereafter, the process proceeds to S40, where the master device 65 can determine whether the number Q of serial connections of the slave devices 70 calculated in S30 is abnormal by comparing it with the design value.

[0067] Specifically, if the number of series Q detected in S30 matches the design value, it can be determined that there is no connection error or communication circuit failure and that the system is normal (S50).

[0068] If the number of series Q calculated in S30 is less than the design value, it can be determined that some kind of abnormality has occurred in the communication system, such as a connection error or a communication circuit failure (S60).

[0069] If the number of series Q calculated in S30 is greater than the design value, it can be determined that more slave devices 70 are connected than the design value (S60).

[0070] 4.Effects This configuration makes it possible to detect the serial number Q of the slave device 70 using the device address, and by comparing this with a set value, it is possible to confirm from the comparison result whether the slave device 70 is connected correctly and whether the communication IC is operating normally.

[0071] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention.

[0072] (1) In the above embodiment, the present technology is applied to the communication system of the power storage bank 21 to detect the number Q of serial connections of the module monitoring device 70. However, the present technology can also be applied to communication systems other than power storage banks as long as they are daisy-chain connected. This technology is particularly effective when the number of serial connections of slave devices varies from case to case.

[0073] (2) In the above embodiment, device addresses are assigned by subtracting 1 from the total number of devices N (descending order) from the bank monitoring device 65 to the top device 70C. The device addresses only need to be consecutive, and for example, they may be assigned by adding 1 (ascending order) from the bank monitoring device 65 to the top device 70C.

[0074] (3) In the above embodiment, the bank monitor 65 confirms the responses of the slave devices 70 in ascending order of device addresses. However, the bank monitor 65 may confirm the responses of the slave devices 70 in descending order of device addresses.

[0075] (4) Without being limited to the above-described embodiment, the present technology may include one master device and multiple slave devices, and the one master device and the multiple slave devices may be daisy-chained via communication lines, and may perform the following: (a) After assigning consecutive device addresses to all devices, the master device confirms responses from each of the plurality of slave devices through communication via the communication line. (b) The master device detects the serial number of the slave device based on the device address of the slave device that has successfully confirmed the response, and compares the detected serial number with a set value.

[0076] 1 Power system 10 Energy Storage Systems 20 Battery panel 21 Energy storage bank 65 Bank monitoring device (master device) 66 CPU 67 Communication IC 68 Pulse transformer 70 Module monitoring device (slave device) 71 Pulse transformer 75 Monitoring IC

Claims

1. A device apparatus, a master device and a plurality of slave devices; One master device and a plurality of slave devices are daisy-chained by a communication line, the master device assigns consecutive device addresses to all devices, and then confirms responses from each of the plurality of slave devices through communication via the communication line; The master device detects the serial number of the slave device based on the device address of the slave device that has successfully confirmed the response, and compares the detected serial number with a set value.

2. The device according to claim 1, the master device sets the total number of all devices connected in the daisy chain based on the maximum number of serial connections of the slave devices; the master device assigns device addresses obtained by subtracting one from the total number of devices to all devices connected in the daisy chain in order from the master device to the top device of the slave devices; The master device confirms responses from the slave devices connected in the daisy chain in ascending order of device addresses, The master device calculates the serial number of the slave devices by subtracting the device address of the slave device that first succeeds in confirming the response from the total number of devices.

3. The device according to claim 2, The total number of devices is a value obtained by adding two to the maximum number of serial connections of the slave devices.

4. The device for monitoring the electric storage bank according to claim 1 or 2, the power storage bank includes a plurality of power storage modules; the slave device is a monitoring device for the power storage module, The master device is a monitoring device for the power storage bank.

5. 1. An energy storage system comprising: a PCS panel that houses a power conversion unit; a battery panel accommodating a power storage bank connected to the power conversion unit via a power line; The storage bank includes: a plurality of power storage modules connected in series; a module monitoring device that monitors the power storage module; a bank monitor; the bank monitoring device and the plurality of module monitoring devices are daisy-chained by a communication line; the bank monitoring device assigns consecutive device addresses to all the monitoring devices, and then confirms responses from each of the plurality of module monitoring devices through communication via the communication line; The bank monitoring device detects the series number of the module monitoring device based on the device address of the module monitoring device that has successfully confirmed the response, and compares the detected series number with a set value.

6. 6. The energy storage system of claim 5, The bank monitoring device detects the number of series of the module monitoring devices and compares it with a set value when the energy storage system is first started up.

7. 7. The energy storage system according to claim 5 or claim 6, An energy storage system having a plurality of battery panels each having a different battery type.

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