Control circuit of battery management system and data storage system

Abstract

The invention discloses a control circuit of a battery management system and a data storage system, and relates to the technical field of power supply control, and the control circuit comprises a rapid turn-off circuit 301 of a discharge MOS tube of a backup battery unit, and the rapid turn-off circuit 301 is used for releasing the junction capacitance voltage of the discharge MOS tube when the discharge MOS tube is turned off; the driving protection circuit 302 of the discharging MOS tube is used for locking the driving level of the discharging MOS tube when the discharging MOS tube is switched off; the fool-proof protection circuit 303 of the backup battery unit is used for turning off the discharge MOS tube under the condition that the positive output end and the negative output end of the backup battery unit are reversely connected, so that the problems that the turn-off time of the discharge MOS tube is relatively long, the loss of the MOS tube and a battery cell is easily caused, and the power supply reliability is influenced in an abnormal power supply scene are solved; and the effects of rapidly turning off the discharge MOS tube in the abnormal power supply scene and improving the power supply reliability are achieved.

Description

Technical Field

[0001] This application relates to the technical field of power supply control, and particularly to a control circuit of a battery management system and a data storage system. Background Art

[0002] Under the background of digital transformation, with the continuous growth of massive data, a unified storage system has emerged. Under normal circumstances, the unified storage system is powered by a power module. In the case of a power module anomaly, it can switch to a BBU (Backup Battery Unit) for power supply to perform hot backup and prevent data loss.

[0003] As the unified storage system is applied to more and more scenarios, the requirements for the security of stored data are increasing day by day. Therefore, higher requirements are also put forward for the security of the BBU (Backup Battery Unit) and the reliability of power supply. In the related art, for the drive circuit of the BBU discharge field effect transistor, in an abnormal scenario, it takes hundreds of nanoseconds for the BMS (Battery Management System) abnormal protection to turn off the discharge field effect transistor, reducing the service life of the field effect transistor and the power supply reliability. In addition, there are also certain security risks when activating the BMS. Summary of the Invention

[0004] This application provides a control circuit of a battery management system and a data storage system to at least solve the problem in the related art that the turn-off time of the discharge field effect transistor of the backup battery unit is relatively long in a power supply abnormal scenario, which easily causes losses to the field effect transistor and the battery cell and affects the power supply reliability.

[0005] This application provides a control circuit of a battery management system, including: a fast turn-off circuit of the discharge field effect transistor of the backup battery unit, with the first end connected to the discharge control signal terminal of the battery management system chip, the second end connected to the gate of the discharge field effect transistor, and the third end connected to the positive output terminal of the backup battery unit, for releasing the junction capacitance voltage of the discharge field effect transistor when the discharge field effect transistor is turned off; a drive protection circuit of the discharge field effect transistor, connected in series between the source of the discharge field effect transistor and the positive output terminal of the backup battery unit, for locking the drive level of the discharge field effect transistor when the discharge field effect transistor is turned off; and an anti-fool protection circuit of the backup battery unit, connected in series between the gate of the discharge field effect transistor and the positive output terminal of the backup battery unit, for turning off the discharge field effect transistor in the case where the positive and negative output terminals of the backup battery unit are connected reversely.

[0006] Exemplarily, the control circuit of the battery management system further includes: an activation circuit of the battery management system chip, disposed between the discharge drive signal terminal of the battery management system chip and the power supply module, and configured to provide an activation voltage less than the protection voltage of the backup battery unit for the battery management system chip in a state where the backup battery unit is not charging.

[0007] Exemplarily, the activation circuit includes: a second resistor and a third resistor connected in series, and a third capacitor connected in parallel across the third resistor, wherein a first end of the second resistor is configured to connect to the power supply module, a second end of the second resistor connects to a first end of the third resistor, and a second end of the third resistor is configured to connect to a ground terminal; a first triode, an emitter of which is configured to connect to the first end of the second resistor, a base of which connects to the first end of the third resistor, and a collector of which is configured to connect to the ground terminal and the discharge drive signal terminal.

[0008] Exemplarily, the activation circuit further includes: a first capacitor and a second capacitor connected in series between the power supply module and the ground terminal; a first diode, a negative electrode of which connects to the power supply module and a positive electrode of which connects to the ground terminal; a second diode, a positive electrode of which connects to the power supply module and a negative electrode of which connects to the first end of the second resistor.

[0009] Exemplarily, the activation circuit further includes: a third diode and a fourth resistor connected in series between the second end of the third resistor and the collector of the first triode, wherein a positive electrode of the third diode connects to the second end of the third resistor and a negative electrode of the third diode connects to the first end of the fourth resistor; a fourth diode and a fifth resistor connected in series between the collector of the first triode and the discharge drive signal terminal, wherein a positive electrode of the fourth diode connects to the collector of the first triode and a negative electrode of the fourth diode connects to the first end of the fifth resistor.

[0010] Exemplarily, the activation circuit further includes: a first resistor connected in series between the first end of the second resistor and the emitter of the first triode; a sixth resistor connected in series between the discharge drive signal terminal and the positive output terminal of the backup battery unit; a seventh resistor connected in series between the positive output terminal of the backup battery unit and the ground terminal.

[0011] Exemplarily, the resistance values of the second resistor and the third resistor satisfy the following condition: U LDO *R3 / (R2 + R3) is less than the protection voltage of the backup battery unit, where R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, and U LDO is the voltage of the power supply module of the battery management system chip.

[0012] Exemplarily, the fast turn-off circuit includes: a fifth diode and a ninth resistor connected in series, and an eighth resistor connected in parallel across the fifth diode and the ninth resistor. The cathode of the fifth diode is connected to the discharge control signal terminal, the anode of the fifth diode is connected to the first end of the ninth resistor, and the resistance value of the ninth resistor is less than that of the eighth resistor; a second triode, with the base connected to the second end of the ninth resistor, the collector connected to the positive output terminal of the backup battery unit, and the emitter for connecting to the gate of the discharge field effect transistor.

[0013] Exemplarily, the fast turn-off circuit includes: a sixth diode, with the anode connected to the base of the second triode and the cathode connected to the emitter of the second triode; a tenth resistor connected in series between the cathode of the sixth diode and the gate of the discharge field effect transistor.

[0014] Exemplarily, the fast turn-off circuit further includes: an eighteenth resistor connected in series between the collector of the second triode and the positive output terminal of the backup battery unit.

[0015] Exemplarily, the resistance value of the ninth resistor satisfies the following condition: (U2 - U1 - U D6 ) / R9 is less than or equal to the sink current value, where U2 is the collector voltage of the second triode, U1 is the turn-off voltage of the discharge field effect transistor, and U D6 is the voltage drop of the sixth diode.

[0016] Exemplarily, the anti-fool protection circuit includes: a first field effect transistor, with the drain for connecting to the gate of the discharge field effect transistor, the source connected to the positive output terminal of the backup battery unit, and the gate for connecting to the ground terminal.

[0017] Exemplarily, the anti-fool protection circuit further includes: a twelfth resistor and a ninth diode connected in series between the ground terminal and the gate of the first field effect transistor, where the anode of the ninth diode is connected to the ground terminal, the cathode of the ninth diode is connected to the first end of the twelfth resistor, and the cathode of the twelfth resistor is connected to the gate of the first field effect transistor.

[0018] Exemplarily, the anti-fool protection circuit further includes: an eighth diode, with the cathode connected to the gate of the first field effect transistor and the anode connected to the positive output terminal of the backup battery unit; a thirteenth resistor connected in parallel across the eighth diode.

[0019] Exemplarily, the anti-fool protection circuit further includes: a fourteenth resistor, with the first end connected to the drain of the first field effect transistor and the second end for connecting to the gate of the discharge field effect transistor.

[0020] Exemplarily, the drive protection circuit includes a negative voltage protection circuit, and the negative voltage protection circuit includes: a fourth capacitor and a fifth capacitor, which are connected in series between the source of the discharge field effect transistor and the gate of the second field effect transistor; a second field effect transistor, the drain of which is used to connect the gate of the discharge field effect transistor, and the source of which is connected to the positive output terminal of the backup battery unit.

[0021] Exemplarily, the drive protection circuit further includes: a seventh diode, the negative electrode of which is used to connect the gate of the discharge field effect transistor, and the positive electrode of which is connected to the drain of the discharge field effect transistor; an eleventh resistor, which is connected in parallel across the seventh diode.

[0022] Exemplarily, the drive protection circuit further includes: a twelfth diode, the negative electrode of which is connected to the gate of the second field effect transistor, and the positive electrode of which is connected to the positive output terminal of the backup battery unit; a sixteenth resistor, which is connected in parallel across the twelfth diode.

[0023] Exemplarily, the drive protection circuit further includes: a fifteenth resistor, which is connected in series between the fifth capacitor and the gate of the second field effect transistor; a seventeenth resistor, which is connected in series between the gate of the discharge field effect transistor and the drain of the second field effect transistor.

[0024] The present application also provides a data storage system, including: a storage device for storing data; a power supply module for supplying power to the storage device; a backup battery unit for supplying power to the storage device in the event of an abnormality of the power supply module, wherein the backup battery unit at least includes a battery pack, a battery management system, and a control circuit of the battery management system.

[0025] With this application, due to the fast turn-off circuit of the discharge field-effect transistor of the backup battery unit, the first end is connected to the discharge control signal terminal of the battery management system chip, the second end is connected to the gate of the discharge field-effect transistor, and the third end is connected to the positive output terminal of the backup battery unit. It is used to release the junction capacitance voltage of the discharge field-effect transistor when the discharge field-effect transistor is turned off, achieving a faster turn-off of the discharge field-effect transistor in abnormal situations, shortening the abnormal turn-off time of the discharge MOS from hundreds of nanoseconds to dozens of nanoseconds; the drive protection circuit of the discharge field-effect transistor is connected in series between the source of the discharge field-effect transistor and the positive output terminal of the backup battery unit, and is used to lock the drive level of the discharge field-effect transistor when the discharge field-effect transistor is turned off, preventing a negative voltage from appearing between the gate and drain of the discharge field-effect transistor. When the system is just powered on or the backup battery unit undergoes a plugging or unplugging operation, it locks the drive signal of the discharge field-effect transistor to prevent the semi-high level from accidentally turning on the discharge field-effect transistor and affecting the system power-on timing; the anti-fool protection circuit of the backup battery unit is connected in series between the gate of the discharge field-effect transistor and the positive output terminal of the backup battery unit, and is used to turn off the discharge field-effect transistor when the positive and negative output terminals of the backup battery unit are connected reversely, preventing potential safety hazards to the battery cells caused by the reverse connection of the positive and negative outputs of the backup battery unit. Therefore, it can solve the problem in the related technology that the turn-off time of the discharge field-effect transistor of the backup battery unit is relatively long in the abnormal power supply scenario, which easily causes losses to the field-effect transistor and the battery cells and affects the power supply reliability, achieving the technical effect of quickly turning off the discharge field-effect transistor in the abnormal power supply scenario and improving the power supply reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 Schematic diagram of a data storage system provided by an embodiment of the present application;

[0028] Figure 2 Schematic diagram of a backup battery unit provided by an embodiment of the present application;

[0029] Figure 3 Schematic diagram of a control circuit of a battery management system provided by an embodiment of the present application;

[0030] Figure 4 Schematic diagram of an optional control circuit of a battery management system provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0032] It should be noted that in the description of the present application, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. The terms "first", "second", etc. in the present application are used to distinguish similar objects and are not used to describe a specific order or sequence.

[0033] In order to enable those skilled in the art of the present technology to better understand the solution of the present application, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0034] First, the terms appearing in this embodiment are explained:

[0035] The battery management system (BMS, Battery Management System) is an electronic system used to manage and control a battery pack (especially a lithium-ion battery pack), and its main function is to ensure the safety, performance and lifespan of the battery pack.

[0036] The backup battery unit (BBU, Backup Battery Unit) is a battery module that provides backup power for a device. It automatically switches to supply power when the main power fails, ensuring that the device (such as a storage device) can still operate normally during a power outage, and protecting data security and system stability.

[0037] Figure 1 FIG. is a schematic diagram of a data storage system provided for an embodiment of the present application; the data storage system includes:

[0038] The storage device 101 is used to store data.

[0039] Among them, the storage device 101 is a device used to save data, supporting the storage and reading of data, providing persistent storage of data for users, and ensuring that the data can still be completely restored after a power outage or system restart. For example, the storage device 101 can be a unified storage array. As a high-performance storage system capable of processing and storing different types of data (such as structured data and unstructured data), the unified storage array provides a unified platform to manage and access various data types such as files, blocks, and objects.

[0040] A power supply module 102 for powering the storage device 101.

[0041] Among them, the power supply module 102 is a unit that provides a stable power supply for the storage device 101, ensuring that the storage device 101 can operate continuously during normal operation and will not malfunction due to insufficient or unstable power. For example, the power supply module 102 can provide a voltage of 220V for the storage device 101.

[0042] A backup battery unit 103 for powering the storage device 101 in the event of an abnormality in the power supply module 102. Among them, the backup battery unit 103 at least includes a battery pack 201, a battery management system 202, and a control circuit 203 of the battery management system 202.

[0043] It should be noted that when the storage device 101 or the power supply module 102 fails, data loss can be prevented through a data backup mechanism to ensure service continuity.

[0044] Exemplarily, the data storage system may include NVDIMM (Non-Volatile Dual In-line Memory Module), which combines volatile DRAM and non-volatile storage technology (such as NAND flash memory), can retain data during power outages or system failures, provides read and write performance close to the memory bus speed, and is suitable for latency-sensitive applications. When a power failure is detected, the data in DRAM is automatically backed up to the flash memory through NVDIMM and the data is restored after the power is restored. The data storage system may also include CBU (Critical Backup Unit), which provides emergency power support for critical devices, mainly used to maintain the operation of the storage device 101 when the power supply module 102 is interrupted or insufficient, to prevent data loss or service interruption. Considering cost performance and data backup power supply power density, in this embodiment, data backup is mainly achieved indirectly through the backup battery unit 103.

[0045] Exemplarily, if the power supply module 102 fails, it may cause the storage device 101 to suddenly lose power, resulting in the loss of unsaved data. When the power supply module 102 is abnormal (such as power outage, failure, or voltage instability), the backup battery unit 103 will be immediately activated to power the storage device 101, ensuring that the storage device 101 can continue to operate before the power supply module 102 is restored, thereby preventing data loss or damage. Exemplarily, the backup battery unit 103 can provide short-term power support for key components (such as memory) of the storage device 101 in the event of a sudden power outage, such as providing power support for several minutes to several hours, ensuring that the data can be safely written to the persistent storage medium, thereby achieving indirect data backup.

[0046] Among them, the components of the backup battery unit 103 include a battery pack 201. The battery pack 201 is a module composed of multiple battery cells and is the core part of the backup battery unit 103. It is responsible for providing power to the storage device 101 when the power module 102 fails. It can be composed of lithium-ion batteries or lead-acid battery packs 201, and has a high energy density and a long service life.

[0047] The components of the backup battery unit 103 also include a battery management system 202. The battery management system 202 is an electronic system used to manage and monitor the battery pack 201 to ensure the safety and performance of the battery pack 201. Its main functions include voltage monitoring, current monitoring, temperature management, equalization control, and fault alarm, etc. By monitoring the status of the battery in real time, it prevents problems such as overcharging, over-discharging, and overheating of the battery, and extends the service life of the battery.

[0048] It should be noted that, on the one hand, in an abnormal scenario, the backup battery unit 103 in the related technology controls the drive circuit of the discharge field effect transistor to turn off the discharge field effect transistor through the battery management system 202, thereby disconnecting the discharge link and realizing the abnormal protection of the backup battery unit 103. However, it takes hundreds of nanoseconds to turn off the discharge field effect transistor, and it is also difficult to quickly turn off the discharge field effect transistor when the positive and negative poles of the battery pack 201 of the battery management system 202 are reversed or the output is short-circuited, which reduces the MOS service life and power supply reliability.

[0049] On the other hand, after the storage device 101 does not access the battery management system 202 for a period of time (such as 24 hours), the battery management system 202 will automatically enter the Shut Down mode. When the backup battery unit 103 works normally, it needs to be activated by the charging link, and the state of the backup battery unit 103 is unknown during activation, so there are certain safety hazards for the backup battery unit 103.

[0050] Exemplarily, if the health condition of the battery cells in the battery pack 201 is unknown, the battery cells may be in an overcharged, over-discharged, short-circuited, aged or other unhealthy states. If the backup battery unit 103 is blindly activated under these unknown states, it may cause the battery to overheat, be damaged, or even trigger a fire or explosion accident. Exemplarily, if there is a risk of overvoltage or overcurrent, the voltage of the battery cells exceeds the normal range, or there is an internal short circuit or other situations, the charging field effect transistor may not be able to correctly control the charging process when charging and activating the backup battery unit 103, resulting in overvoltage or overcurrent and damaging the battery and the charging circuit. Exemplarily, if there is a battery balancing problem, the voltages of the individual battery cells in the battery that has not been working for a long time may be unbalanced. Directly charging and activating the backup battery unit 103 may exacerbate this imbalance and reduce the overall life of the battery. Exemplarily, if there is a fault in the control circuit 203, other control circuits 203 of the backup battery unit 103 malfunction during the Shut Down mode, such as a fault in the battery management system 202. When activated, it may not be able to correctly manage and protect the battery, increasing the safety hazard.

[0051] To solve the above problems, the control circuit 203 of the battery management system 202 is also provided in the backup battery unit 103 of the present application. The control circuit 203 of the battery management system 202 includes a fast turn-off circuit for the discharge field effect transistor of the backup battery unit 103. The first end of the fast turn-off circuit is connected to the discharge control signal terminal of the battery management system 202, the second end of the fast turn-off circuit is connected to the gate of the discharge field effect transistor, and the third end of the fast turn-off circuit is connected to the positive output terminal of the backup battery unit 103, which is used to release the junction capacitance voltage of the discharge field effect transistor when the discharge field effect transistor is turned off, achieving a faster turn-off of the discharge field effect transistor in abnormal situations, shortening the abnormal turn-off time of the discharge field effect transistor from several hundred nanoseconds to several tens of nanoseconds. The control circuit 203 of the battery management system 202 also includes a drive protection circuit for the discharge field effect transistor, which is connected in series between the source electrode of the discharge field effect transistor and the positive output terminal of the backup battery unit 103, and is used to lock the drive level of the discharge field effect transistor when the discharge field effect transistor is turned off, preventing a negative voltage from appearing between the gate and the drain of the discharge field effect transistor. When the system is just powered on or the backup battery unit 103 has a plugging or unplugging action, the drive signal of the discharge field effect transistor is locked to prevent the semi-high level from accidentally turning on the discharge field effect transistor and affecting the power-on timing of the system. The control circuit 203 of the battery management system 202 also includes an anti-fool protection circuit for the backup battery unit 103, which is connected in series between the gate of the discharge field effect transistor and the positive output terminal of the backup battery unit 103, and is used to turn off the discharge field effect transistor in the case where the positive and negative output terminals of the backup battery unit 103 are connected reversely, preventing potential safety hazards to the battery cells caused by the reverse connection of the positive and negative outputs of the backup battery unit 103.

[0052] Therefore, the control circuit 203 of the present application can quickly turn off the charge and discharge field effect transistors in abnormal scenarios (such as short - circuit abnormality, reverse connection of positive and negative poles, cell damage, load abnormality), preventing damage to the MOS during abnormal protection when exceeding the SOA area (Safe Operating Area) of the discharge MOS transistor (the power and voltage range within which the discharge field effect transistor can operate normally under certain conditions without being damaged. When the field effect transistor operates outside its safe operating area, it may overheat, break down, or even be permanently damaged), reducing the damage to the discharge MOS transistor in abnormal scenarios, eliminating the hidden danger of cell fire and explosion caused by the damage of the discharge MOS transistor, improving the power supply stability and reliability, and also isolating the connection between the battery and the storage device 101, preventing secondary fault spread of the cell, charge - discharge control module, and power supply link in scenarios such as cell damage, abnormal power supply link, and load abnormality (for example, if the cells are unbalanced or over - discharged, quickly turning off the discharge field effect transistor can prevent further damage to the cells and prevent the abnormal state from spreading along the power supply link, protecting other components from being affected).

[0053] The control circuit 203 of the battery management system 202 further includes an activation circuit of the battery management system 202, which is arranged between the discharge drive signal terminal of the battery management system 202 and the power supply module, and is used to provide an activation voltage less than the protection voltage of the backup battery unit 103 for the battery management system 202 when the backup battery unit 103 is not charging. This activation circuit is a Shut Down mode activation circuit. When the storage device 101 is powered on or when the backup battery unit 103 is replaced in the Shut Down mode, it can automatically activate the backup battery unit 103 without relying on the charging process. The activation voltage is lower than the permanent protection voltage of the backup battery unit 103, and there is no need to activate the backup battery unit 103 through charging to exit the Shut Down mode. It can automatically identify the state of the backup battery unit 103 and does not charge when the state of the backup battery unit 103 is unknown, avoiding the problem in the related art that when the backup battery unit 103 enters the Shut Down mode, it is necessary to activate the charging link to monitor the battery state, and in the case where the system does not know the state of the backup battery unit 103, it may cause abnormal activation, thereby damaging the cell or the power supply link.

[0054] The embodiment of the present application also provides a backup battery unit, Figure 2 which is a schematic diagram of a backup battery unit provided by an embodiment of the present application, as Figure 2 shown:

[0055] The battery pack 201 ( Figure 2 the Cells in).

[0056] The battery management system 202 (BMS chip, for example, the model can be BQ40Z50 / SH366006), a charging (CHG, Charge) link, a discharging (DSG, Discharge) link, a charging field-effect transistor, a discharging field-effect transistor, and a FUSE (fuse) respectively connected in series on the charging link and the discharging link. The BMS chip manages the charging field-effect transistor and the discharging field-effect transistor. When the in-position signals (system in-position signal SYS_PRESENT_L, BBU in-position signal BBU_PRESENT_L) are valid and there is no alarm information in the BMS, the charging field-effect transistor and the discharging field-effect transistor are turned on. When the in-position signals are invalid and there is an alarm information in the BMS, the charging field-effect transistor and the discharging field-effect transistor are turned off.

[0057] The control circuit 203 of the battery management system 202 is arranged between the DSG terminal and the PACK+ terminal on the backup battery unit. The control circuit 203 includes a fast turn-off circuit for the discharging field-effect transistor of the backup battery unit. The first end of the fast turn-off circuit is connected to the discharging control signal terminal of the battery management system 202, the second end is connected to the gate of the discharging field-effect transistor, and the third end is connected to the positive output terminal of the backup battery unit, which is used to release the junction capacitance voltage of the discharging field-effect transistor when the discharging field-effect transistor is turned off, achieving a faster turn-off of the discharging field-effect transistor in case of an abnormality, shortening the abnormal turn-off time of the discharging MOS from several hundred nanoseconds to dozens of nanoseconds. The control circuit 203 includes a driving protection circuit for the discharging field-effect transistor, which is connected in series between the source of the discharging field-effect transistor and the positive output terminal of the backup battery unit, and is used to lock the driving level of the discharging field-effect transistor when the discharging field-effect transistor is turned off, preventing a negative voltage from appearing between the gate and the drain of the discharging field-effect transistor. When the system is just powered on or the backup battery unit has a plugging or unplugging action, the driving signal of the discharging field-effect transistor is locked to prevent the discharging field-effect transistor from being accidentally turned on by a semi-high level, affecting the power-on timing of the system. The control circuit 203 includes an anti-fool protection circuit for the backup battery unit, which is connected in series between the gate of the discharging field-effect transistor and the positive output terminal of the backup battery unit, and is used to turn off the discharging field-effect transistor in case the positive and negative output terminals of the backup battery unit are connected reversely, preventing potential safety hazards to the battery cells caused by the reverse connection of the positive and negative outputs of the backup battery unit.

[0058] The backup battery unit further includes an over-voltage protection chip (OVP, Over Voltage Protection), which is used to prevent the battery voltage from exceeding the safe range, thereby avoiding damage to the battery or related components.

[0059] The backup battery unit also includes an Electrically Erasable Programmable Read-Only Memory (EEPROM), which can store data even after the power is turned off and is used to store the configuration and operation data of the BMS. It is connected to a Serial Clock Line (SCL) for synchronizing data transmission between the EEPROM and external devices (such as a microcontroller), a Serial Data Line (SDA1) for bidirectional data transmission between the EEPROM and external devices, and a Write Protect (WP) signal pin for controlling the write permission of the EEPROM.

[0060] The backup battery unit also includes a power supply module LD0, which can be a low-dropout linear regulator or a power conversion module for providing a stable voltage to the BMS chip. A surface mount connector SMC, SMD for surface mount technology on the circuit board to provide electrical connection between the BMS and other systems or components, a Negative Temperature Coefficient (NTC) thermistor for monitoring the battery temperature, and a resistance sensor Rsns for indirectly measuring the magnitude of the current flowing through the battery by measuring the voltage drop across the resistor.

[0061] An embodiment of the present application provides a control circuit for a battery management system. Figure 3 As shown in the schematic diagram of the control circuit for a battery management system provided by an embodiment of the present application, Figure 3 as shown, the control circuit of the battery management system includes:

[0062] A fast turn-off circuit 301 for the discharge field effect transistor Q3 of the backup battery unit, with its first end connected to the discharge control signal terminal DSG of the battery management system chip, its second end connected to the gate of the discharge field effect transistor Q3, and its third end connected to the positive output terminal PACK+ of the backup battery unit, for releasing the junction capacitance voltage of the discharge field effect transistor when the discharge field effect transistor Q3 is turned off.

[0063] It should be noted that the discharge field effect transistor Q3 can be a MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor). That is, the fast turn-off circuit 301 of the discharge field effect transistor Q3 belongs to a part of the drive circuit of the discharge field effect transistor Q3. The drive circuit of the discharge field effect transistor Q3 is responsible for controlling the discharge process of the backup battery unit to ensure that the discharge link of the battery pack can be quickly and safely cut off when necessary. When the backup battery unit is working normally, the battery management system chip controls the discharge field effect transistor Q3 to conduct through the discharge control signal terminal DSG. When an abnormal situation is detected, the battery management system chip controls the discharge field effect transistor Q3 to turn off and quickly reduces the voltage of the positive output terminal DSG of the backup battery unit, triggering the fast turn-off circuit 301 to quickly discharge the junction capacitance voltage of the field effect transistor Q3.

[0064] Exemplarily, the fast turn-off circuit 301 of the discharge field effect transistor Q3 may include a PNP-type second triode Q6. The base of the second triode Q6 is used to connect to the discharge control signal terminal DSG. The emitter of the second triode Q6 is used to connect to the gate of the discharge field effect transistor Q3. The collector of the second triode Q6 is connected to the positive output terminal PACK+ of the backup battery unit. When the discharge field effect transistor Q3 starts to discharge quickly, the base voltage of the second triode Q6 drops rapidly, causing the second triode Q6 to enter the conducting state. At this time, the junction capacitance voltage of the discharge field effect transistor Q3 is quickly discharged through the emitter and collector pins of the second triode Q6. The fast turn-off circuit 301 may also include a fifth diode D5 and a ninth resistor R9 connected in parallel, together with an eighth resistor R8 connected in parallel with them, which jointly form a voltage discharge path. The voltage discharge path is connected in series between the discharge control signal terminal DSG and the base of the second triode Q6. When the junction capacitance voltage between the gate and drain of the discharge field effect transistor Q3 drops, the discharge speed of the junction capacitance voltage is accelerated through the voltage discharge path. The resistance value of the ninth resistor R9 is set to be smaller than that of the eighth resistor R8 to provide a faster voltage discharge rate.

[0065] That is, the resistance values of the second triode Q6 in the fast turn-off circuit 301 of the discharge field effect transistor Q3 and the ninth resistor R9 in the voltage discharge path are set such that the transition time of the discharge field effect transistor Q3 from on to off is greatly shortened, from several hundred nanoseconds to several tens of nanoseconds, thereby greatly reducing the damage to the discharge field effect transistor Q3 and avoiding the excessive damage to the battery cells in the backup battery unit and even the risk of fire and explosion.

[0066] The driving protection circuit 302 of the discharge field effect transistor Q3 is connected in series between the source electrode of the discharge field effect transistor Q3 and the positive output terminal PACK+ of the backup battery unit, and is used to lock the driving level of the discharge field effect transistor Q3 when the discharge field effect transistor Q3 is turned off.

[0067] It should be noted that the driving protection circuit 302 of the discharge field effect transistor Q3 is used to further ensure the safe turn-off of the discharge field effect transistor Q3 when the power supply system is just powered on or the backup battery unit has a plugging or unplugging action. When the discharge field effect transistor Q3 is turned off, the driving level of the discharge field effect transistor Q3 is locked to prevent a negative voltage from appearing between the gate and drain of the discharge field effect transistor. When the power supply system is just powered on or the backup battery unit has a plugging or unplugging action, the driving signal of the discharge field effect transistor is locked to prevent the semi-high level from accidentally turning on the discharge field effect transistor and affecting the power-on timing of the system.

[0068] Exemplarily, the driving protection circuit 302 of the discharge field effect transistor Q3 may be a fourth capacitor C4, a fifth capacitor C5, and a second field effect transistor Q5 that are connected in series in sequence between the source electrode of the discharge field effect transistor Q3 and the positive output terminal PACK+ of the backup battery unit. The gate of the second field effect transistor Q5 is used to connect to the fifth capacitor C5, the drain of the second field effect transistor Q5 is used to connect to the gate of the discharge field effect transistor, and the source electrode of the second field effect transistor Q5 is connected to the positive output terminal PACK+ of the backup battery unit. When the power supply system is just powered on or the backup battery unit has a plugging or unplugging action, the charging states of the fourth capacitor C4 and the fifth capacitor C5 will change rapidly, prompting the second field effect transistor Q5 to turn on, thereby immediately locking the voltage of the junction capacitance between the gate and drain of the discharge field effect transistor Q3, avoiding a possible negative voltage between the gate and drain of the discharge field effect transistor Q3, ensuring that the discharge field effect transistor Q3 is quickly turned off when the backup battery unit is not in use, and at the same time no harmful negative voltage is generated.

[0069] The anti-fool protection circuit 303 of the backup battery unit is connected in series between the gate of the discharge field effect transistor Q3 and the positive output terminal PACK+ of the backup battery unit, and is used to turn off the discharge field effect transistor Q3 when the positive output terminal PACK+ and the negative output terminal PACK- of the backup battery unit are connected reversely.

[0070] It should be noted that when the positive output terminal PACK+ and the negative output terminal PACK- of the backup battery unit are connected reversely, the anti-fool protection circuit 303 of the backup battery unit quickly locks the driving level of the discharge field effect transistor Q3 and quickly turns off the discharge field effect transistor Q3 to prevent potential circuit damage and safety hazards.

[0071] Exemplarily, the anti-fool protection circuit 303 may include a first field-effect transistor Q4. The drain of the first field-effect transistor Q4 is used to connect to the gate of the discharge field-effect transistor Q3. The source of the first field-effect transistor Q4 is connected to the positive output terminal PACK+ of the backup battery unit. The gate of the first field-effect transistor Q4 is used to connect to the ground terminal. When the positive output terminal PACK+ and the negative output terminal PACK- of the backup battery unit are connected reversely, the first field-effect transistor Q4 conducts, quickly locks the drive signal of the discharge field-effect transistor Q3, and immediately turns off the discharge field-effect transistor Q3. That is, by utilizing the fast response characteristic of the first field-effect transistor Q4, it is ensured that in an extreme situation where the positive and negative poles of the backup battery unit are connected reversely, safety measures can be taken immediately to prevent the battery cells from being damaged.

[0072] Through the present application, due to the fast turn-off circuit 301 of the discharge field-effect transistor of the backup battery unit, with the first end connected to the discharge control signal terminal of the battery management system chip, the second end connected to the gate of the discharge field-effect transistor, and the third end connected to the positive output terminal of the backup battery unit, which is used to release the junction capacitance voltage of the discharge field-effect transistor when the discharge field-effect transistor is turned off, it realizes accelerating the turn-off of the discharge field-effect transistor in an abnormal situation, shortening the abnormal turn-off time of the discharge MOS from several hundred nanoseconds to dozens of nanoseconds; the drive protection circuit 302 of the discharge field-effect transistor, which is connected in series between the source of the discharge field-effect transistor and the positive output terminal of the backup battery unit, is used to lock the drive level of the discharge field-effect transistor when the discharge field-effect transistor is turned off, prevent a negative voltage from appearing between the gate and the drain of the discharge field-effect transistor, and lock the drive signal of the discharge field-effect transistor when the system is just powered on or the backup battery unit has a plugging and unplugging action, preventing the semi-high level from accidentally turning on the discharge field-effect transistor and affecting the power-on timing of the system; the anti-fool protection circuit 303 of the backup battery unit, which is connected in series between the gate of the discharge field-effect transistor and the positive output terminal of the backup battery unit, is used to turn off the discharge field-effect transistor when the positive output terminal and the negative output terminal of the backup battery unit are connected reversely, preventing potential safety hazards to the battery cells caused by the reverse connection of the positive and negative output terminals of the backup battery unit. Therefore, it can solve the problem in the related art that the turn-off time of the discharge field-effect transistor of the backup battery unit is relatively long in a power supply abnormal scenario, which easily causes losses to the field-effect transistor and the battery cells and affects the power supply reliability, and achieve the technical effect of quickly turning off the discharge field-effect transistor in a power supply abnormal scenario and improving the power supply reliability.

[0073] In an exemplary embodiment, the control circuit of the battery management system further includes: an activation circuit of the battery management system chip, which is arranged between the discharge drive signal terminal PACK of the battery management system chip and the power supply module, and is used to provide an activation voltage less than the protection voltage of the backup battery unit for the battery management system chip in a state where the backup battery unit is not charging.

[0074] Since the activation circuit provides an activation voltage for the battery management system chip that is lower than the protection voltage of the backup battery unit, when the storage device is started or the backup battery unit is replaced, the activation circuit can automatically activate the backup battery unit without relying on the charging process, avoiding the safety risks that may be caused by charging when the state of the backup battery unit is uncertain, ensuring that the battery cells are protected from damage, and significantly improving the power supply stability and safety of the unified storage system when the power supply system is the unified storage system, meeting the requirements of high data security.

[0075] Figure 4 The figure is a schematic diagram of a control circuit of an optional battery management system provided by an embodiment of the present application. As Figure 4 shown, in an exemplary embodiment, the activation circuit includes: a second resistor R2 and a third resistor R3 connected in series, and a third capacitor C3 connected in parallel across the third resistor R3. Among them, the first end of the second resistor R2 is used to connect to the power supply module, the second end of the second resistor R2 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is used to connect to the ground terminal; a first triode Q1, the emitter of which is used to connect to the first end of the second resistor R2, the base is connected to the first end of the first resistor R1, and the collector is used to connect to the ground terminal and the discharge drive signal terminal PACK.

[0076] Among them, the second resistor R2 plays a current-limiting role, controlling the rate of charge flowing from the power supply module to the activation circuit, preventing excessive current from damaging the activation circuit. The third resistor R3 is used in cooperation with the second resistor R2 to jointly determine the activation voltage.

[0077] Among them, the third capacitor C3 is connected in parallel across the third resistor R3. The third capacitor C3 is used to store charges to quickly activate the PNP-type first triode Q1 and control the opening time of the activation circuit through its charge and discharge characteristics.

[0078] Among them, after the third capacitor C3 is charged, the base voltage of the first triode Q1 rises. When it reaches the opening threshold, it conducts, transmitting the activation voltage to the discharge drive signal terminal PACK to activate the battery management system control chip.

[0079] Exemplarily, when the data storage system is started or the backup battery unit is replaced (there is an insertion and extraction action for the backup battery unit), the voltage of the power supply module charges the third capacitor C3 through the second resistor R2. The charging process of the third capacitor C3 raises the voltage of the base of the first triode Q1. When the voltage of the base of the first triode Q1 reaches a certain threshold, the first triode Q1 conducts, forming a path between its emitter and collector, and transmitting the activation voltage to the discharge drive signal terminal PACK to activate the chip of the battery management system.

[0080] The activation circuit of this embodiment can control the activation voltage generated by the activation circuit to be less than the protection voltage of the backup battery unit through the cooperation of the first triode Q1, the second resistor R2, the third resistor R3, and the third capacitor C3, ensuring that the chip of the battery management system can be reliably started without charging activation, avoiding potential safety hazards that may be brought by charging due to the unknown state of the battery cells in the battery pack during the activation of the backup battery unit, and improving the safety of power supply.

[0081] In an implementation manner, the activation circuit further includes: a first capacitor C1 and a second capacitor C2, connected in series between the power supply module and the ground terminal; a first diode D1, with the negative electrode connected to the power supply module and the positive electrode connected to the ground terminal; a second diode D2, with the positive electrode connected to the power supply module and the negative electrode connected to the first end of the second resistor R2.

[0082] Among them, the first capacitor C1 and the second capacitor C2 are used as filter capacitors at the entrance of the power supply module to filter out high-frequency interference between the power supply module and the chip of the battery management system, ensuring the stability of the activation voltage.

[0083] Among them, the first diode D1 plays an isolation role to achieve hot-swap protection for the power supply module of the chip of the battery management system. For example, the first diode D1 can be a TVS tube (Transient Voltage Suppressor Diode).

[0084] Among them, the second diode D2 plays an isolation role and uses the unidirectional conduction characteristic to prevent the voltage of the data storage system from flowing back. Exemplarily, when the data storage system is powered off, the second diode D2 prevents the voltage on the third capacitor C3 from flowing back to the power supply module, causing the current of the system power supply logic confusion to flow back to the system and affecting the power-off timing sequence.

[0085] The activation circuit of this embodiment prevents the influence of voltage noise on the circuit through the first capacitor C1 and the second capacitor C2, and ensures the logic sequence when the data storage system is powered off through the first diode D1 and the second diode D2, avoiding the residual voltage from flowing back to the system end and affecting the normal shutdown process of the device, thereby ensuring that the voltage of the power supply module entering the activation circuit is not affected by the voltage of other parts in the circuit, and improving the stability and power supply quality of the activation circuit.

[0086] In an implementation manner, the activation circuit further includes: a third diode D3 and a fourth resistor R4, connected in series between the second end of the third resistor R3 and the collector of the first triode Q1, wherein the positive electrode of the third diode D3 is connected to the second end of the third resistor R3, and the negative electrode of the third diode D3 is connected to the first end of the fourth resistor R4; a fourth diode D4 and a fifth resistor R5, connected in series between the collector of the first triode Q1 and the discharge drive signal terminal PACK, wherein the positive electrode of the fourth diode D4 is connected to the collector of the first triode Q1, and the negative electrode of the fourth diode D4 is connected to the first end of the fifth resistor R5.

[0087] Wherein, the third diode D3 is a voltage stabilizing diode, which is used to prevent the voltage from flowing reversely from the collector of the first triode Q1 into the third resistor R3 and the third capacitor C3, and protect the stability of the activation circuit.

[0088] Wherein, the fourth resistor R4 is a current limiting resistor, which controls the flow of current from the third diode D3 to the collector of the first triode Q1.

[0089] Wherein, the fourth diode D4 utilizes the unidirectional conduction characteristic to ensure that the voltage flows unidirectionally from the collector of the first triode Q1 to the discharge drive signal terminal PACK, and prevent the voltage of the battery cell (PACK+) from affecting the activation circuit.

[0090] Wherein, the fifth resistor R5 is a current limiting resistor, connected in series after the fourth diode D4, and controls the speed of current entering the battery management system chip.

[0091] In this embodiment, through the isolation of the third diode D3 and the fourth diode D4, the safety of the activation circuit is improved, and the damage caused by the reverse flow of voltage to the circuit is prevented. Through the current limiting effect of the fourth resistor R4 and the fifth resistor R5, the speed of current entering the battery management system chip is controlled, the battery management system chip is protected from the impact of instantaneous large current, and the chip life is extended.

[0092] In an implementation manner, the activation circuit further includes: a first resistor R1, connected in series between the first end of the second resistor R2 and the emitter of the first triode Q1; a sixth resistor R6, connected in series between the discharge drive signal terminal PACK and the positive output terminal PACK+ of the backup battery unit; a seventh resistor R7, connected in series between the positive output terminal PACK+ of the backup battery unit and the ground terminal.

[0093] Wherein, the first resistor R1 is a current limiting resistor, which further controls the current from the power supply module to the first triode Q1, and ensures the stability and safety of the activation circuit.

[0094] Among them, the sixth resistor R6 is a current-limiting resistor that controls the current between the discharge drive signal terminal PACK and the positive output terminal PACK+ of the backup battery unit.

[0095] Among them, the seventh resistor R7 is a grounding resistor used to protect the positive output terminal PACK+ of the backup battery unit and prevent abnormal voltage from instantaneously impacting and affecting the health of the battery cells.

[0096] In this embodiment, through the first resistor R1, the sixth resistor R6, and the seventh resistor R7, the current control ability of the activation circuit is enhanced, abnormal current damage to the activation circuit and the battery cells is avoided, the service life of the activation circuit is extended, and the power supply stability and reliability are further improved.

[0097] In an implementation manner, the resistance values of the second resistor R2 and the third resistor R3 satisfy the following condition: U LDO *R3 / (R2 + R3) is less than the protection voltage of the backup battery unit, where R2 is the resistance value of the second resistor R2, R3 is the resistance value of the third resistor R3, and U LDO is the voltage of the power supply module of the battery management system chip.

[0098] It should be noted that the activation voltage U of the Shut Down mode of the backup battery unit is U=(12*R3 / (R2 + R3)). It is necessary to reasonably select the resistance values of the second resistor R2 and the third resistor R3 to ensure that the activation voltage U of the Shut Down mode of the backup battery unit is lower than the permanent protection voltage of the backup battery unit, without damaging the backup battery unit, and activating the battery management system chip of the backup battery unit.

[0099] Exemplarily, the activation voltage U of the Shut Down mode of the backup battery unit is 3 - 7V, and U LDO is the voltage of the power supply module of the battery management system chip, which can be 12V. Then, the second resistor R2 is selected as a resistor with a value of 1 kΩ to 2 kΩ, the third resistor R3 is selected with a value of 0.7 kΩ to 2 kΩ, and U = ∫Idt / C3. According to actual application requirements, the third capacitor C3 is selected with a value of 0.1 μF to 0.47 μF to ensure that the voltage U LDO *R3 / (R2 + R3) is less than the protection voltage of the backup battery unit.

[0100] By appropriately selecting the resistance values of R2 and R3, the activation circuit of this embodiment ensures the controllability and safety of the activation voltage generated by the activation circuit, so that the activation voltage does not pose an overvoltage risk to the backup battery unit, realizes the fast and safe activation of the battery management system chip, thereby improving the power supply stability and safety of the unified storage system and meeting the requirements of high data security.

[0101] As shown Figure 3 In an exemplary embodiment, the fast turn-off circuit 301 includes a fifth diode D5 and a ninth resistor R9 connected in series, and an eighth resistor R8 connected in parallel across the fifth diode D5 and the ninth resistor R9. The cathode of the fifth diode D5 is connected to the discharge control signal terminal DSG, the anode of the fifth diode D5 is connected to the first end of the ninth resistor R9, and the resistance value of the ninth resistor R9 is less than that of the eighth resistor R8. A second triode Q6 has its base connected to the second end of the ninth resistor R9, its collector connected to the positive output terminal PACK+ of the backup battery unit, and its emitter for connecting to the gate of the discharge field-effect transistor Q3.

[0102] Among them, the fifth diode D5 functions as a one-way conductor. When the fifth diode D5 is not conducting, the eighth resistor R8 serves as the driving path for the gate of the discharge field-effect transistor Q3, and the discharge control signal (DSG signal) can be smoothly transmitted to the gate of the discharge field-effect transistor Q3. When the fifth diode D5 conducts, it allows the voltage to rapidly drop through the ninth resistor R9, causing the base voltage of the second triode Q6 to rapidly drop.

[0103] Among them, the second triode Q6 is used to conduct when the base voltage drops, accelerating the discharge of the gate voltage of the discharge field-effect transistor Q3 to achieve fast turn-off.

[0104] Exemplarily, in the discharge state of the backup battery unit, when the discharge field-effect transistor Q3 is operating normally and the fifth diode D5 is not conducting, the discharge control signal is transmitted to the gate of the discharge field-effect transistor Q3 through the eighth resistor R8. Once an abnormal situation such as a short circuit or overcurrent anomaly is detected and the discharge field-effect transistor Q3 needs to be quickly turned off, there is a junction capacitance between the gate and the drain of the discharge field-effect transistor Q3. When the discharge field-effect transistor Q3 is turned off, the junction capacitance voltage needs to be quickly discharged. The battery management system chip rapidly reduces the voltage of the discharge control signal. At this time, the fifth diode D5 conducts, and the gate voltage of the discharge field-effect transistor Q3 is rapidly reduced through the low resistance value of the ninth resistor R9. The resistance value of the ninth resistor R9 is less than that of the eighth resistor R8, and the base voltage of the second triode Q6 also rapidly drops. The rapid drop of the base voltage of the second triode Q6 triggers the second triode Q6 to conduct, further accelerating the discharge of the junction capacitance voltage between the gate and the drain of the discharge field-effect transistor Q3, achieving the turn-off of the discharge field-effect transistor Q3 within dozens of nanoseconds, significantly shortening the turn-off time, and protecting the discharge field-effect transistor Q3 from damage.

[0105] The fast turn-off circuit 301 of this embodiment, through the cooperation of the fifth diode D5, the eighth resistor R8, and the ninth resistor R9, enables the base voltage of the second triode Q6 to drop rapidly when the discharge MOS Q3 tube turns off, accelerating the second triode Q6, achieving the fast turn-off of the discharge field-effect tube Q3 in abnormal situations, ensuring that the battery management chip can quickly isolate the battery pack in an emergency, improving the response speed and safety of the backup battery unit, reducing the risk of thermal damage to the discharge field-effect tube Q3 under abnormal conditions, preventing the spread of faults, and ensuring the overall stability and reliability of the data storage system.

[0106] In an implementation manner, the fast turn-off circuit 301 includes: a sixth diode D6, with the positive electrode connected to the base of the second triode Q6 and the negative electrode connected to the emitter of the second triode Q6; a tenth resistor R10, connected in series between the negative electrode of the sixth diode D6 and the gate of the discharge field-effect tube Q3.

[0107] Among them, the sixth diode D6 is connected in parallel between the base and the emitter of the second triode Q6. Using its unidirectional conduction characteristic, it prevents the current from exceeding the sink current capacity of the battery management system chip and burning out the battery management system chip during the rapid discharge of the junction capacitance voltage between the gate and the drain of the discharge field-effect tube Q3.

[0108] Among them, the tenth resistor R10 is a current-limiting resistor. Since the gate resistance is very small, there will be oscillations between the drain and the source, which is not safe for the discharge field-effect tube Q3. The tenth resistor R10 is connected in series between the negative electrode of the second six-diode D6 and the gate of the discharge field-effect tube Q3 to limit the current and ensure safety during the discharge process.

[0109] The fast turn-off circuit 301 of this embodiment is provided with a sixth diode D6 and a tenth resistor R10. When the gate voltage of the discharge field-effect tube Q3 drops rapidly, the sixth diode D6 ensures that the current does not flow back into the base of the second triode Q6, protecting the battery management system chip from damage. The tenth resistor R10 limits the current passing through the discharge field-effect tube Q3, preventing excessive current from damaging the gate of the discharge field-effect tube Q3, thereby improving the safety during the turn-off process of the discharge field-effect tube Q3 and ensuring that while achieving efficient turn-off, it will not cause damage to the battery management system chip and the discharge field-effect tube Q3 in the backup battery unit.

[0110] In an implementation manner, the fast turn-off circuit 301 further includes: an eighteenth resistor R18, connected in series between the collector of the second triode Q6 and the positive output terminal PACK+ of the backup battery unit.

[0111] Among them, the eighteenth resistor R18 is a current-limiting resistor, which is connected in series between the collector of the second triode Q6 and PACK+, preventing the turn-off current of the second triode Q6 from being too large in abnormal situations and damaging the fast turn-off circuit 301, improving the current control ability of the fast turn-off circuit 301 in abnormal scenarios, and ensuring the stability and safety of the backup battery unit.

[0112] In an implementation manner, the resistance value of the ninth resistor R9 satisfies the following condition: (U2 - U1 - U D6 ) / R9 is less than or equal to the sink current value, where U2 is the collector voltage of the second triode Q6, U1 is the turn-off voltage of the discharge field effect transistor Q3, and U D6 is the voltage drop of the sixth diode D6, which can be 0.3V.

[0113] It should be noted that the turn-off voltage U2 of the discharge field effect transistor Q3, the collector voltage U1 of the second triode Q6, and U D6 and the voltage drop of the sixth diode D6 and the sink current value are known, so that the maximum value of the resistance value of the ninth resistor R9 can be determined. The resistance value of the ninth resistor R9 is designed to satisfy the condition that (U2 - U1 - U D6 ) / R9 is less than the sink current value, ensuring that when the gate voltage of the discharge field effect transistor Q3 drops rapidly, the current passing through the ninth resistor R9 does not exceed the sink current capacity of the drive chip, preventing the drive chip from being damaged due to overload.

[0114] It should be noted that the smaller the resistance value of the ninth resistor R9, the more obvious the effect of quickly turning off the discharge field effect transistor Q3. The resistance value selection of the ninth resistor R9 should consider the sink current capacity of the battery management system chip. Within the allowable sink current range of the battery management system chip (the sink current can be designed with a 10% derating, such as 10 milliamps, and the maximum is 9 milliamps), the resistance value of the ninth resistor R9 should be as small as possible to ensure that the discharge field effect transistor Q3 is quickly turned off without generating negative pressure.

[0115] The fast turn-off circuit 301 of this embodiment realizes the fast turn-off of the discharge field effect transistor Q3 in abnormal scenarios through the resistance setting of the ninth resistor R9, and at the same time protects the battery management system chip of the backup battery unit, preventing damage to the battery cells and potential safety risks, and providing technical support for the power supply safety and reliability of the data storage system.

[0116] In an implementation manner, the anti-fool protection circuit 303 includes: a first field effect transistor Q4, the drain of which is used to connect to the gate of the discharge field effect transistor Q3, the source of which is connected to the positive output terminal PACK+ of the backup battery unit, and the gate of which is used to connect to the ground terminal.

[0117] Exemplarily, when the backup battery unit plug is correctly inserted, the gate of the first field-effect transistor Q4 is usually in a high-impedance state, so it will not affect the drain of the discharge field-effect transistor Q3. However, when the positive output terminal PACK+ and the negative output terminal PACK- of the backup battery unit are connected reversely, the positive output terminal PACK+ is directly connected to the ground terminal through the drain-source of the first field-effect transistor Q4, resulting in an increase in the gate potential of the first field-effect transistor Q4. Eventually, the first field-effect transistor Q4 conducts, cutting off the path from the drain of the discharge field-effect transistor Q3 to the ground terminal, locking the drive level of the discharge MOS transistor Q3, and thus quickly turning off the discharge field-effect transistor Q3.

[0118] The anti-fool protection circuit 303 of this embodiment is set up through the first field-effect transistor Q4. When the positive and negative poles of the backup battery unit are connected reversely, it can promptly respond to the reverse connection situation, quickly turn off the discharge field-effect transistor Q3, prevent the battery cell from being damaged due to reverse current, avoid the risk of fire or explosion in the storage system, and eliminate potential safety hazards.

[0119] In an implementation manner, the anti-fool protection circuit 303 further includes: a twelfth resistor R12 and a ninth diode D9, which are connected in series between the ground terminal and the gate of the first field-effect transistor Q4. Among them, the positive pole of the ninth diode D9 is connected to the ground terminal, the negative pole of the ninth diode D9 is connected to the first end of the twelfth resistor R12, and the negative pole of the twelfth resistor R12 is connected to the gate of the first field-effect transistor Q4.

[0120] Among them, the twelfth resistor R12 is a current-limiting resistor, which is used to control the rising speed of the gate voltage of the first field-effect transistor Q4 and prevent misoperation caused by sudden changes in the gate voltage of the first field-effect transistor Q4.

[0121] Among them, the ninth diode D9 has a forward conduction characteristic. Under normal operation, the ninth diode D9 prevents current from flowing back. In abnormal situations, the voltage can cause the positive output terminal PACK+ of the backup battery unit to pass through the ninth diode D9 to the gate of the first field-effect transistor Q4, triggering the protection mechanism.

[0122] Exemplarily, the ninth diode D9 is connected in series with the twelfth resistor R12. When the positive and negative poles of the backup battery unit are connected reversely, the voltage is applied to the gate of the first field-effect transistor Q4 through the ninth diode D9. The rising gate voltage triggers the first field-effect transistor Q4 to conduct, cutting off the path of the discharge field-effect transistor Q3. At the same time, the twelfth resistor R12 controls the rising rate of the gate voltage of the first field-effect transistor Q4 to prevent instantaneous overload of the first field-effect transistor Q4.

[0123] The anti-fool protection circuit 303 of this embodiment adds voltage control and current limiting functions on the basis of the anti-fool protection function by connecting the twelfth resistor R12 and the ninth diode D9 in series between the grounding terminal and the gate of the first field-effect transistor Q4, avoiding the malfunction of the first field-effect transistor Q4 caused by the sudden change of the gate voltage, and further improving the stability and safety of the backup battery unit.

[0124] In an implementation manner, the anti-fool protection circuit 303 further includes: an eighth diode D8, with the negative pole connected to the gate of the first field-effect transistor Q4 and the positive pole connected to the positive output terminal PACK+ of the backup battery unit; a thirteenth resistor R13, connected in parallel across the eighth diode D8.

[0125] Among them, the eighth diode D8 is used to isolate the positive output terminal PACK+ of the backup battery unit and the gate of the first field-effect transistor Q4, ensuring that the current can only flow in one direction when the positive and negative poles of the backup battery unit are reversed, and preventing reverse damage to the battery cells.

[0126] Among them, the thirteenth resistor R13 is connected in parallel across the eighth diode D8. When the eighth diode D8 bears a high voltage, the parallel connection of R13 can shunt the current, protecting the eighth diode D8 from being broken down, improving the high-voltage resistance ability of the eighth diode D8, and preventing the eighth diode D8 from being damaged due to excessive voltage.

[0127] The existence of the eighth diode D8 in the anti-fool protection circuit 303 of this embodiment ensures a unidirectional current path from PACK+ to the gate, preventing the flow of reverse current, enhancing the isolation ability of the circuit. The thirteenth resistor R13 is used to share the voltage on the eighth diode D8, thus ensuring the safety of the circuit and the battery cells under extreme conditions such as high voltage or reverse electrode connection, extending the life of the backup battery unit, and reducing the maintenance cost.

[0128] In an implementation manner, the anti-fool protection circuit 303 further includes: a fourteenth resistor R14, with the first end connected to the drain of the first field-effect transistor Q4 and the second end used to connect to the gate of the discharge field-effect transistor Q3.

[0129] Among them, the fourteenth resistor R14 is used to control the voltage from the gate of the first field-effect transistor Q4 to the discharge field-effect transistor Q3. When the first field-effect transistor Q4 is turned on, the current from the drain of the first field-effect transistor Q4 to the ground is limited through the fourteenth resistor R14, thereby controlling the voltage change at the gate of the discharge field-effect transistor Q3, ensuring that no harmful voltage difference is generated when the protection is started, and avoiding the gate of the discharge field-effect transistor Q3 from bearing too high or too low voltage.

[0130] The anti-fool protection circuit 303 of this embodiment realizes the protection of the gate voltage of the discharge field effect transistor Q3 by setting the fourteenth resistor R14, avoiding secondary damage to the battery cell and the drive circuit, enabling the drive circuit to quickly respond to protection while improving the overall safety performance of the discharge circuit of the backup battery unit.

[0131] In an exemplary embodiment, the drive protection circuit 302 includes a negative voltage protection circuit, and the negative voltage protection circuit includes: a fourth capacitor C4 and a fifth capacitor C5, connected in series between the source of the discharge field effect transistor Q3 and the gate of the second field effect transistor Q5; a second field effect transistor Q5, the drain of which is used to connect to the gate of the discharge field effect transistor Q3, and the source is connected to the positive output terminal PACK+ of the backup battery unit.

[0132] Among them, the fourth capacitor C4 and the fifth capacitor C5 utilize the characteristics of capacitors to conduct alternating current and block direct current, quickly respond when the voltage changes, trigger the turn-on action of the second field effect transistor Q5, and the capacitors C4 and C5 are connected in series to prevent the influence of the failure short-circuit characteristics of one of the capacitors on the circuit performance.

[0133] Among them, the second field effect transistor Q5 is used to conduct when the voltages of the fourth capacitor C4 and the fifth capacitor C5 change, accelerating the voltage discharge of the gate of the discharge field effect transistor Q3 to the ground terminal, and realizing the rapid turn-off of the discharge field effect transistor Q3.

[0134] Exemplarily, when an abnormal situation occurs (such as a short circuit), the gate voltage of the discharge field effect transistor Q3 drops rapidly, and the voltage changes of the fourth capacitor C4 and the fifth capacitor C5 will trigger the second field effect transistor Q5 to conduct, accelerating the discharge of the gate voltage of the discharge field effect transistor Q3 and preventing the occurrence of negative voltage between the gate and the drain of the discharge MOS transistor Q3. Exemplarily, when the backup battery unit starts to work for the first time (when the data storage system is powered on or there is a plugging and unplugging action of the backup battery unit), the discharge field effect transistor Q3 is turned off, and the voltage changes of the fourth capacitor C4 and the fifth capacitor C5 will trigger the second field effect transistor Q5 to conduct, locking the drive level of the discharge field effect transistor Q3 to prevent the discharge field effect transistor Q3 from being turned on by a semi-high level, affecting the power-on timing of the data storage system.

[0135] The negative voltage protection circuit in the drive protection circuit 302 of the discharge field effect transistor in this embodiment is connected in series between the source electrode of the discharge field effect transistor and the positive output terminal of the backup battery unit. It is used to lock the drive level of the discharge field effect transistor when the discharge field effect transistor is turned off, prevent negative voltage from appearing between the gate and drain of the discharge field effect transistor, lock the drive signal of the discharge field effect transistor when the system is just powered on or the backup battery unit has a plugging or unplugging action, prevent the semi-high level from accidentally turning on the discharge field effect transistor, greatly improve the power supply stability and safety of the storage system, reduce the damage to the battery cells and circuits in abnormal scenarios, extend the service life of the storage system, and reduce the operation and maintenance costs.

[0136] In an exemplary embodiment, the drive protection circuit 302 further includes: a seventh diode D7, whose negative electrode is used to connect to the gate of the discharge field effect transistor Q3, and the positive electrode is connected to the drain of the discharge field effect transistor Q3; an eleventh resistor R11, which is connected in parallel across the seventh diode D7.

[0137] Exemplarily, one end of the resistor R11 and the diode D7 is connected to the gate of the discharge field effect transistor Q3 through the gate drive resistor R10 of the discharge field effect transistor Q3, and the other end is connected to the drain of the discharge field effect transistor Q3.

[0138] Among them, the seventh diode D7 is used to provide a low-impedance path when the gate voltage of the discharge field effect transistor Q3 needs to be quickly released. When the discharge field effect transistor Q3 needs to be quickly turned off, the voltage at the gate of the discharge field effect transistor Q3 can quickly discharge to the drain of the discharge field effect transistor Q3 through the seventh diode D7, accelerating the voltage drop and accelerating the turn-off process of the field effect transistor.

[0139] Among them, the eleventh resistor R11 is connected in parallel across the seventh diode D7, which is used to prevent the seventh diode D7 from being mis-conducted during normal operation. Under normal circumstances, the high-impedance characteristic of the eleventh resistor R11 will not affect the normal operation of the discharge field effect transistor Q3. However, when the gate voltage of the discharge field effect transistor Q3 discharges, the eleventh resistor R11 can share the current and limit the current when the seventh diode D7 conducts, protecting the seventh diode D7 from overheating or damage due to large current.

[0140] In the drive protection circuit 302 of the discharge field effect transistor in this embodiment, the eleventh resistor R11 and the seventh diode D7 constitute the drive protection circuit 302 of the discharge field effect transistor Q3. The seventh diode D7 can significantly accelerate the turn-off speed of the discharge field effect transistor Q3. The eleventh resistor R11 ensures the stability and safety of the circuit in abnormal situations, prevents the discharge field effect transistor Q3 from overheating or being damaged, and improves the reliability of the entire backup power supply unit.

[0141] In an implementation, the drive protection circuit 302 further includes: a twelfth diode D10, with its cathode connected to the gate of the second field effect transistor Q5 and its anode connected to the positive output terminal PACK+ of the backup battery unit; a sixteenth resistor R16, connected in parallel across the twelfth diode D10.

[0142] Among them, the twelfth diode D10 is used to prevent the second field effect transistor Q5 from being mis-conducted when the discharge field effect transistor Q3 is turned off, and to avoid the gate voltage of the second field effect transistor Q5 flowing reversely into the fifth capacitor C5 or the gate of the discharge field effect transistor Q3.

[0143] Among them, the sixteenth resistor R16 is connected in parallel across the twelfth diode D10 and is used to limit the current when the twelfth diode D10 is conducting, so as to avoid damage to the gate of the second field effect transistor Q5 due to excessive current.

[0144] Exemplarily, under normal operating conditions, the twelfth diode D10 prevents the voltage at the positive output terminal PACK+ of the backup battery unit from leaking to other circuits through the gate of the second field effect transistor Q5. However, when the discharge field effect transistor Q3 is turned off, the twelfth diode D10 allows the gate voltage to quickly flow through the positive electrode to the positive output terminal PACK+ of the backup battery unit, and the presence of the sixteenth resistor R16 ensures that the current is within a safe range, thereby protecting the gate of the second field effect transistor Q5 from excessive voltage impact.

[0145] The drive protection circuit 302 of this embodiment realizes electrical isolation between the discharge field effect transistor Q3 and the second field effect transistor Q5 through the twelfth diode D10, prevents the accidental reverse flow of the gate voltage, limits the current through the sixteenth resistor R16, protects the gate of the second field effect transistor Q5 from voltage impact, reduces the thermal loss of the gate of the second field effect transistor Q5 during rapid voltage changes, extends the service life of the second field effect transistor Q5 and the discharge field effect transistor Q3, and ensures the long-term stability and safety of the backup battery unit.

[0146] In an implementation, the drive protection circuit 302 further includes: a fifteenth resistor R15, connected in series between the fifth capacitor C5 and the gate of the second field effect transistor Q5; a seventeenth resistor R17, connected in series between the gate of the discharge field effect transistor Q3 and the drain of the second field effect transistor Q5.

[0147] Among them, the fifteenth resistor R15 is a current-limiting resistor, which is used to control the current of the fifth capacitor C5 charging the gate of the second field effect transistor Q5, ensuring that when the second field effect transistor Q5 needs to respond quickly under abnormal conditions, the rapid transmission of current can be guaranteed, and at the same time, damage to the gate of the second field effect transistor Q5 caused by excessive transient current can be prevented, that is, rapid and safe response is achieved.

[0148] Among them, the seventeenth resistor R17 is used to control the voltage from the drain of the second field-effect transistor Q5 to the gate of the discharge field-effect transistor Q3, ensuring that during the turn-off process of the gate of the discharge field-effect transistor Q3, the voltage provided by the drain of the second field-effect transistor Q5 is within a safe range, and no harmful voltage will be generated on the gate of the discharge field-effect transistor Q3, avoiding the gate of the discharge field-effect transistor Q3 from being subjected to negative pressure or excessive voltage, thereby preventing the discharge field-effect transistor Q3 from being damaged.

[0149] In the drive protection circuit 302 of this embodiment, through the combination of the fifteenth resistor R15 and the fifth capacitor C5, the response of the second field-effect transistor Q5 in abnormal situations becomes more rapid and accurate, reducing the influence time of abnormal situations on the circuit, and improving the response speed and protection efficiency of the circuit. By setting the seventeenth resistor R17, the voltage control ability of the circuit in the fast turn-off state is further enhanced, avoiding the damage of the discharge field-effect transistor Q3 due to voltage fluctuations, and ensuring the long-term stability and reliability of the backup power supply unit.

[0150] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases, the former is a better implementation method.

[0151] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this article can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0152] The above has introduced in detail a control circuit and a data storage system of a battery management system provided by this application. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of this application, several improvements and modifications can still be made to this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A control circuit of a battery management system, characterized in that Comprising: A fast turn-off circuit for the discharge field-effect transistor of the backup battery unit, with the first end connected to the discharge control signal terminal of the battery management system chip, the second end connected to the gate of the discharge field-effect transistor, and the third end connected to the positive output terminal of the backup battery unit, for releasing the junction capacitance voltage of the discharge field-effect transistor when the discharge field-effect transistor is turned off; The drive protection circuit of the discharge field-effect transistor, connected in series between the source of the discharge field-effect transistor and the positive output terminal of the backup battery unit, for locking the drive level of the discharge field-effect transistor when the discharge field-effect transistor is turned off; The anti-fool protection circuit of the backup battery unit, connected in series between the gate of the discharge field-effect transistor and the positive output terminal of the backup battery unit, for turning off the discharge field-effect transistor in the case where the positive and negative output terminals of the backup battery unit are connected reversely.

2. The control circuit of the battery management system according to claim 1, wherein The control circuit of the battery management system further includes: The activation circuit of the battery management system chip, provided between the discharge drive signal terminal of the battery management system chip and the power supply module, for providing an activation voltage less than the protection voltage of the backup battery unit to the battery management system chip in the state where the backup battery unit is not charging.

3. The control circuit of the battery management system according to claim 2, wherein The activation circuit includes: A second resistor and a third resistor connected in series, and a third capacitor connected in parallel across the third resistor, wherein the first end of the second resistor is used to connect to the power supply module, the second end of the second resistor is connected to the first end of the third resistor, and the second end of the third resistor is used to connect to the ground terminal; A first triode, with the emitter used to connect to the first end of the second resistor, the base connected to the first end of the third resistor, and the collector used to connect to the ground terminal and the discharge drive signal terminal.

4. The control circuit of the battery management system according to claim 3, wherein, The activation circuit further includes: A first capacitor and a second capacitor, connected in series between the power supply module and the ground terminal; A first diode, with the negative pole connected to the power supply module and the positive pole connected to the ground terminal; A second diode, with the positive pole connected to the power supply module and the negative pole connected to the first end of the second resistor.

5. The control circuit of the battery management system according to claim 3, characterized in that, The activation circuit further includes: A third diode and a fourth resistor, connected in series between the second end of the third resistor and the collector of the first triode, wherein the positive pole of the third diode is connected to the second end of the third resistor, and the negative pole of the third diode is connected to the first end of the fourth resistor; A fourth diode and a fifth resistor, connected in series between the collector of the first triode and the discharge drive signal terminal, wherein the positive pole of the fourth diode is connected to the collector of the first triode, and the negative pole of the fourth diode is connected to the first end of the fifth resistor.

6. The control circuit of the battery management system according to claim 3, characterized in that, The activation circuit further includes: A first resistor, connected in series between the first end of the second resistor and the emitter of the first triode; A sixth resistor, connected in series between the discharge drive signal terminal and the positive output terminal of the backup battery unit; A seventh resistor, connected in series between the positive output terminal of the backup battery unit and the ground terminal.

7. The control circuit of the battery management system according to any one of claims 3 to 6, characterized in that, The resistance values of the second resistor and the third resistor satisfy the following condition: U LDO *R3 / (R2 + R3) is less than the backup battery unit protection voltage, where R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, and U LDO is the voltage of the power supply module of the battery management system chip.

8. The control circuit of the battery management system according to claim 1, characterized in that, The fast turn-off circuit includes: A fifth diode and a ninth resistor connected in series, and an eighth resistor connected in parallel across the fifth diode and the ninth resistor, wherein the negative electrode of the fifth diode is connected to the discharge control signal terminal, the positive electrode of the fifth diode is connected to the first end of the ninth resistor, and the resistance value of the ninth resistor is less than the resistance value of the eighth resistor; A second triode, with the base connected to the second end of the ninth resistor, the collector connected to the positive output terminal of the backup battery unit, and the emitter for connecting to the gate of the discharge field effect transistor.

9. The control circuit of the battery management system according to claim 8, wherein, The fast turn-off circuit includes: A sixth diode, with the positive electrode connected to the base of the second triode and the negative electrode connected to the emitter of the second triode; A tenth resistor, connected in series between the negative electrode of the sixth diode and the gate of the discharge field effect transistor.

10. The control circuit of the battery management system according to claim 8, characterized in that, The fast turn-off circuit further includes: An eighteenth resistor, connected in series between the collector of the second triode and the positive output terminal of the backup battery unit.

11. The control circuit of the battery management system according to any one of claims 9 to 10, characterized in that, The resistance value of the ninth resistor satisfies the following condition: (U2 - U1 - U D6 ) / R9 is less than or equal to the sinking current value, where U2 is the collector voltage of the second triode, U1 is the turn-off voltage of the discharge field effect transistor, and U D6 is the voltage drop of the sixth diode.

12. The control circuit of the battery management system according to claim 1, characterized in that, The anti-fool protection circuit includes: A first field effect transistor, with the drain for connecting to the gate of the discharge field effect transistor, the source connected to the positive output terminal of the backup battery unit, and the gate for connecting to the ground terminal.

13. The control circuit of the battery management system according to claim 12, characterized in that, The anti-fool protection circuit further includes: A twelfth resistor and a ninth diode, connected in series between the ground terminal and the gate of the first field effect transistor, wherein the positive electrode of the ninth diode is connected to the ground terminal, the negative electrode of the ninth diode is connected to the first end of the twelfth resistor, and the negative electrode of the twelfth resistor is connected to the gate of the first field effect transistor.

14. The control circuit of the battery management system according to claim 12, wherein The anti-fool protection circuit further includes: An eighth diode, with the negative electrode connected to the gate of the first field effect transistor and the positive electrode connected to the positive output terminal of the backup battery unit; A thirteenth resistor, connected in parallel across the eighth diode.

15. The control circuit of the battery management system according to claim 12, characterized in that, The anti-fool protection circuit further includes: A fourteenth resistor, with the first end connected to the drain of the first field effect transistor and the second end for connecting to the gate of the discharge field effect transistor.

16. The control circuit of the battery management system according to claim 1, wherein The drive protection circuit includes a negative voltage protection circuit, and the negative voltage protection circuit includes: A fourth capacitor and a fifth capacitor, connected in series between the source of the discharge field effect transistor and the gate of the second field effect transistor; The second field effect transistor, with the drain for connecting to the gate of the discharge field effect transistor and the source connected to the positive output terminal of the backup battery unit.

17. The control circuit of the battery management system according to claim 16, characterized in that, The drive protection circuit further includes: A seventh diode, with the negative electrode for connecting to the gate of the discharge field effect transistor and the positive electrode connected to the drain of the discharge field effect transistor; An eleventh resistor, connected in parallel across the seventh diode.

18. The control circuit of the battery management system according to claim 16, characterized in that, The drive protection circuit further includes: A twelfth diode, with the negative electrode connected to the gate of the second field effect transistor and the positive electrode connected to the positive output terminal of the backup battery unit; A sixteenth resistor, connected in parallel across the twelfth diode.

19. The control circuit of the battery management system according to claim 16, characterized in that, The drive protection circuit further includes: A fifteenth resistor, connected in series between the fifth capacitor and the gate of the second field effect transistor; A seventeenth resistor, connected in series between the gate of the discharge field effect transistor and the drain of the second field effect transistor.

20. A data storage system, characterized in that, Includes: A storage device for storing data; A power supply module for supplying power to the storage device; A backup battery unit for powering the storage device in the event of an abnormality in the power supply module, wherein the backup battery unit includes at least a battery pack, a battery management system, and a control circuit of the battery management system according to any one of claims 1 to 19.

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