Real-time clock system of battery pack

Abstract

The invention discloses a battery pack real-time clock system, and belongs to the technical field of battery pack management. The MCU is electrically connected with a low-voltage conversion module, and the low-voltage conversion module is electrically connected with an isolation module; the communication interface of the MCU is connected with the communication interface of the isolation module. The isolation module is electrically connected with a high-voltage acquisition module and an RTC; a communication interface of the high-voltage acquisition module is connected with a communication interface of the isolation module; a communication interface of the RTC is connected with a communication interface of the isolation module or a communication interface of the high-voltage acquisition module; the RTC is electrically connected with a high-voltage conversion module, and the high-voltage conversion module is connected with the battery pack; the low-voltage conversion module is connected with a low-voltage power supply. According to the invention, the normal operation of the real-time clock function of the battery pack under any working condition is ensured, and the normal operation of the SOX related function is ensured. And the full-working-condition normal operation of the real-time clock is realized through lowest cost increase and simplest scheme change.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pack management, and particularly relates to a battery pack real-time clock system. Background Art

[0002] To improve the accuracy of battery pack SOX estimation and enhance the user experience of end-users, the battery pack BMS requires an RTC (Real-Time Clock) function for time counting. For example, the SOC function relies on OCV look-up table for calibration, and the accuracy of the OCV look-up table is related to the length of the battery pack's stationary time. The battery pack SOH is not only strongly correlated with the number of charge and discharge cycles (cycle life), but also related to the length of the battery pack's stationary placement time (calendar life).

[0003] In an automobile, due to the presence of a 12V or 24V low-voltage battery, when the battery pack is in the automobile, the BMS will continuously operate in a powered state. During the operation of an electric aircraft, a 28V low-voltage power supply also provides power to the BMS.

[0004] Conventional Solution 1 (as shown in Figure 3 ): Convert the 12V, 24V, or 28V power supply from the low-voltage battery into 5V constant power to supply power to the RTC function of the BMS and maintain its normal operation. Once the low-voltage power supply is lost, the RTC function will also stop operating.

[0005] When the low-voltage power supply is present, the low-voltage power supply chip converts the battery power supply into a low-voltage power supply LV_5V (taking the system internal power supply as 5V as an example, and other working levels are also applicable). LV_5V supplies power to the MCU and the RTC chip. At the same time, LV_5V supplies power to the high-voltage acquisition ADC through an isolation module. There is data communication between the MCU and the RTC, and the MCU and the high-voltage acquisition ADC achieve data communication through an isolation chip. In the single battery pack mode (when the battery pack is taken off the production line and not installed in the power consumption system, or when it is removed from an automobile or an aircraft in the battery swapping mode), if no additional low-voltage power supply network is provided, then the BMS system loses the low-voltage power supply, and the RTC timing function will also stop working. Due to the loss of the RTC function, the SOX-related functions that strongly rely on RTC timing cannot operate normally.

[0006] High-cost Solution 2 (as shown in Figure 4 ): The overall architecture is similar to Conventional Solution 1, with an additional high-voltage to low-voltage power supply. Power is taken from the total voltage of the battery pack, and the high-voltage electricity is converted into low-voltage power supply through an isolation transformer. When the low-voltage battery power supply is lost, the normal operation of the RTC is achieved through this power supply circuit. However, the high-voltage to low-voltage power supply circuit design is complex, costly, and has high power consumption.

[0007] Based on this, the present invention designs a battery pack real-time clock system to solve the above problems. Summary of the Invention

[0008] In view of the above disadvantages of the prior art, the present invention provides a real-time clock system for a battery pack.

[0009] To achieve the above object, the present invention is realized through the following technical solutions: A real-time clock system for a battery pack, including an MCU; The MCU is electrically connected to a low-voltage conversion module, and the low-voltage conversion module is electrically connected to an isolation module; The communication interface of the MCU is connected to the communication interface of the isolation module; The isolation module is electrically connected to a high-voltage acquisition module and an RTC; The communication interface of the high-voltage acquisition module is connected to the communication interface of the isolation module; The communication interface of the RTC is connected to the communication interface of the isolation module or the communication interface of the high-voltage acquisition module; The RTC is electrically connected to a high-voltage conversion module, and the high-voltage conversion module is connected to the battery pack; The low-voltage conversion module is connected to a low-voltage power supply.

[0010] Furthermore, the communication interface includes at least one data transmission pin and at least one data reception pin.

[0011] Furthermore, when the communication interface of the RTC is connected to the communication interface of the isolation module, the high-voltage acquisition module and the RTC have a set of communication interfaces, the isolation module has four sets of communication interfaces, and the MCU has two sets of communication interfaces.

[0012] Furthermore, when the communication interface of the RTC is connected to the communication interface of the high-voltage acquisition module, the MCU and the RTC have a set of communication interfaces, the isolation module has two sets of communication interfaces, and the high-voltage acquisition module has two sets of communication interfaces.

[0013] Furthermore, the low-voltage conversion module is a low-voltage power chip.

[0014] Furthermore, the isolation module is a high-low voltage isolation chip.

[0015] Furthermore, the high-voltage acquisition module is an ASIC chip.

[0016] Furthermore, the high-voltage conversion module includes, but is not limited to, an LDO, an LDO-like, or a DC / DC power supply.

[0017] Beneficial effects: In the present invention, the RTC is adjusted to the high-voltage region to avoid the RTC from stopping working when the low-voltage power supply is lost in the low-voltage region. Then, by adding a high-voltage conversion module, direct power supply to the RTC from the high-voltage region is achieved after the loss of the low-voltage power supply, ensuring that the real-time clock function operates normally under any working conditions of the battery pack and guaranteeing the normal operation of SOX-related functions. The normal operation of the real-time clock under all working conditions is realized through the lowest-cost increase and the simplest scheme change. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a block diagram of a real-time clock system for a battery pack according to Embodiment 1 of the present invention; Figure 2 It is a block diagram of a real-time clock system for a battery pack according to Embodiment 2 of the present invention; Figure 3 It is a block diagram of an existing real-time clock system for a battery pack Figure 1 ; Figure 4 It is a block diagram of an existing real-time clock system for a battery pack Figure 2 . Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0021] The following further describes the present invention with reference to the embodiments.

[0022] Embodiment 1: Please refer to Figure 1 , a real-time clock system for a battery pack, including an MCU; The MCU is electrically connected to a low-voltage conversion module, and the low-voltage conversion module is electrically connected to an isolation module; The communication interface of the MCU is connected to the communication interface of the isolation module.

[0023] The isolation module is electrically connected to a high-voltage acquisition module and an RTC; The communication interface of the high-voltage acquisition module is connected to the communication interface of the isolation module; The communication interface of the RTC is connected to the communication interface of the isolation module; The RTC is electrically connected to a high-voltage conversion module, and the high-voltage conversion module is connected to the battery pack; The low-voltage conversion module is connected to a 12V, 24V or 28V power supply.

[0024] The communication interface includes at least one data transmission pin and at least one data reception pin.

[0025] The low-voltage conversion module is a low-voltage power chip.

[0026] The isolation module is a high-low voltage isolation chip.

[0027] The high-voltage acquisition module is an ASIC chip.

[0028] The high-voltage conversion module includes, but is not limited to, an LDO, an LDO-like device, or a DC / DC power supply.

[0029] When the communication interface of the RTC is connected to the communication interface of the isolation module, the high-voltage acquisition module and the RTC have a set of communication interfaces, the isolation module has four sets of communication interfaces, and the MCU has two sets of communication interfaces.

[0030] The data transmission pin of the first set of communication interfaces of the MCU is connected to the data reception pin of the first set of communication interfaces of the isolation module; The data reception pin of the first set of communication interfaces of the MCU is connected to the data transmission pin of the first set of communication interfaces of the isolation module; The data reception pin of the second set of communication interfaces of the isolation module is connected to the data transmission pin of a set of communication interfaces of the high-voltage acquisition module; The data transmission pin of the second set of communication interfaces of the isolation module is connected to the data reception pin of a set of communication interfaces of the high-voltage acquisition module; The data transmission pin of the second set of communication interfaces of the MCU is connected to the data reception pin of the third set of communication interfaces of the isolation module; The data reception pin of the second set of communication interfaces of the MCU is connected to the data transmission pin of the third set of communication interfaces of the isolation module; The data reception pin of the fourth set of communication interfaces of the isolation module is connected to the data transmission pin of a set of communication interfaces of the RTC; The data transmission pin of the fourth set of communication interfaces of the isolation module is connected to the data reception pin of a set of communication interfaces of the RTC.

[0031] When the BMS low-voltage power supply exists, the low-voltage power supply chip converts the battery power supply into a low-voltage power supply LV_5V. LV_5V powers the MCU. At the same time, LV_5V powers the ASIC chip and RTC through the isolation module. The RTC communicates with the MCU through the high-low voltage isolation chip for data communication.

[0032] The high-voltage area power supply module directly converts the high voltage of the entire battery pack into the HV_5V_2 power supply. The RTC can independently obtain power from HV_5V or HV_5V_2. When the low-voltage area power supply is lost, the RTC is powered by HV_5V_2 to maintain operation. The normal operating current of the RTC is within 10mA, so the power supply design of the high-voltage conversion module is simple. By making the minimum architecture change and the lowest cost change to the current BMS design scheme, power can be obtained from the high-voltage area power supply.

[0033] Adjust the RTC to the high-voltage area to prevent the RTC from stopping working when the low-voltage power supply is lost in the low-voltage area. Then, by adding a high-voltage conversion module, the high-voltage area directly powers the RTC after the low-voltage power supply is lost, ensuring that the real-time clock function operates normally under any working conditions of the battery pack and ensuring the normal operation of SOX-related functions. The full-condition normal operation of the real-time clock is achieved through the lowest cost increase and the simplest scheme change.

[0034] Embodiment 2: Please refer to Figure 2 ; A battery pack real-time clock system, including an MCU; The MCU is electrically connected to a low-voltage conversion module, and the low-voltage conversion module is electrically connected to an isolation module; The communication interface of the MCU is connected to the communication interface of the isolation module.

[0035] The isolation module is electrically connected to a high-voltage acquisition module and an RTC; The communication interface of the high-voltage acquisition module is connected to the communication interface of the isolation module; The communication interface of the RTC is connected to the communication interface of the high-voltage acquisition module; The RTC is electrically connected to a high-voltage conversion module, and the high-voltage conversion module is connected to the battery pack; The low-voltage conversion module is connected to a 12V, 24V, or 28V power supply.

[0036] The communication interface includes at least one data sending pin and at least one data receiving pin.

[0037] The low-voltage conversion module is a low-voltage power supply chip.

[0038] Low-voltage conversion module: The low voltage is 9 - 16V in passenger cars, or 18 - 32V in commercial vehicles, or 22 - 30.3V in commercial aircraft.

[0039] High-voltage conversion module: The high voltage in the total voltage of the electric vehicle battery pack is 100V - 1000V, and the high voltage in the total voltage of the commercial vehicle or commercial aircraft battery pack is about 1500V; The isolation module is a high-low voltage isolation chip.

[0040] The high-voltage acquisition module is an ASIC chip.

[0041] The high-voltage conversion module includes but is not limited to LDO, LDO-like, or DC / DC power supplies.

[0042] When the communication interface of the RTC is connected to the communication interface of the high-voltage acquisition module, the MCU and RTC have a set of communication interfaces, the isolation module has two sets of communication interfaces, and the high-voltage acquisition module has two sets of communication interfaces.

[0043] The data transmission pin of a set of communication interfaces of the MCU is connected to the data reception pin of the first set of communication interfaces of the isolation module; The data reception pin of a set of communication interfaces of the MCU is connected to the data transmission pin of the first set of communication interfaces of the isolation module; The data reception pin of the second set of communication interfaces of the isolation module is connected to the data transmission pin of a set of communication interfaces of the high-voltage acquisition module; The data transmission pin of the second set of communication interfaces of the isolation module is connected to the data reception pin of a set of communication interfaces of the high-voltage acquisition module; The data transmission pin of the second set of communication interfaces of the high-voltage acquisition module is connected to the data reception pin of a set of communication interfaces of the RTC; The data reception pin of the second set of communication interfaces of the high-voltage acquisition module is connected to the data transmission pin of a set of communication interfaces of the RTC.

[0044] When the BMS low-voltage power supply exists, the low-voltage power chip converts the battery power supply into a low-voltage power supply LV_5V. LV_5V powers the MCU. At the same time, LV_5V powers the ASIC chip and RTC through the isolation module. The RTC no longer communicates directly with the MCU but communicates with the ASIC chip. Data communication between the ASIC chip and the MCU is through the isolation chip, and data communication between the RTC and the MCU is bridged by the ASIC chip.

[0045] The high-voltage area power module directly converts the high voltage of the entire battery pack into the HV_5V_2 power supply. The RTC independently draws power from HV_5V or HV_5V_2. When the low-voltage area power is lost, the RTC is powered by HV_5V_2 to maintain operation. The normal operating current of the RTC is within 10mA, so the power supply design of the high-voltage conversion module is simple. By making the smallest architecture change and the lowest cost change to the current BMS design scheme, power can be taken from the high-voltage area power supply.

[0046] Adjust the RTC to the high-voltage area to prevent the RTC from stopping working when the low-voltage power supply is lost in the low-voltage area. Then, by adding a high-voltage conversion module, the RTC can be directly powered by the high-voltage area after the low-voltage power supply is lost, ensuring that the real-time clock function operates normally under any working conditions of the battery pack and guaranteeing the normal operation of SOX-related functions. The full-condition normal operation of the real-time clock is achieved with the lowest cost increase and the simplest scheme change.

[0047] MCU: microprogrammed control unit, which is a microprogram controller or a single-chip microcomputer.

[0048] BMS: battery management system

[0049] SOX: state of X, which is a general term for the state of charge of the battery pack, and is subdivided into SOC, SOH, etc.

[0050] SOC: state of charge

[0051] SOH: state of health

[0052] OCV: open circuit voltage

[0053] RTC: real time clock

[0054] ADC: analog digital converter

[0055] LDO: Low dropout regulator DC / DC: direct current to direct current

[0056] ASIC: application specific integrated circuit

[0057] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A real-time clock system for a battery pack, comprising an MCU, characterized in that: The MCU is electrically connected to a low-voltage conversion module, and the low-voltage conversion module is electrically connected to an isolation module; The communication interface of the MCU is connected to the communication interface of the isolation module; The isolation module is electrically connected to a high-voltage acquisition module and an RTC; The communication interface of the high-voltage acquisition module is connected to the communication interface of the isolation module; The communication interface of the RTC is connected to the communication interface of the isolation module or the communication interface of the high-voltage acquisition module; The RTC is electrically connected to a high-voltage conversion module, and the high-voltage conversion module is connected to the battery pack; The low-voltage conversion module is connected to a low-voltage power supply.

2. The real-time clock system of the battery pack according to claim 1, wherein The communication interface includes at least one data transmission pin and at least one data reception pin.

3. The real-time clock system of the battery pack according to claim 2, characterized in that, When the communication interface of the RTC is connected to the communication interface of the isolation module, the high-voltage acquisition module and the RTC have a set of communication interfaces, the isolation module has four sets of communication interfaces, and the MCU has two sets of communication interfaces.

4. The real-time clock system of the battery pack according to claim 3, characterized in that, When the communication interface of the RTC is connected to the communication interface of the high-voltage acquisition module, the MCU and the RTC have a set of communication interfaces, the isolation module has two sets of communication interfaces, and the high-voltage acquisition module has two sets of communication interfaces.

5. The real-time clock system of the battery pack according to claim 3 or 4, characterized in that, The low-voltage conversion module is a low-voltage power chip.

6. The real-time clock system of the battery pack according to claim 2, characterized in that, The isolation module is a high-low voltage isolation chip.

7. The real-time clock system of the battery pack according to claim 2, wherein The high-voltage acquisition module is an ASIC chip.

8. The real-time clock system of the battery pack according to claim 2, characterized in that The high-voltage conversion module includes, but is not limited to, an LDO, an LDO-like, or a DC / DC power supply.

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