MP2796-based high-voltage system low-cost power-down circuit

Abstract

The utility model discloses an MP2796-based low-cost power down circuit for a high-voltage system. The MP2796-based low-cost power down circuit comprises a control unit, a plurality of AFE units, an ultra-wide isolation optocoupler and an isolation optocoupler, the control unit is connected with one AFE unit through an ultra-wide isolation optocoupler; in the plurality of AFE units, adjacent AFE units are connected through an isolation optical coupler. By implementing the circuit provided by the utility model, a low-cost power failure mode can be realized, the hardware cost can be reduced, and the safety and the stability of a system in high-voltage energy storage application can be effectively ensured.

Description

Technical Field

[0001] This utility model relates to the field of high-voltage system power-off circuit technology, and in particular to a low-cost power-off circuit for high-voltage systems based on MP2796. Background Technology

[0002] In energy storage systems, 1500V high-voltage systems typically consist of multiple battery packs connected in series. Each battery pack generally contains 52 cells, and each pack is further divided into multiple modules, for example, 13 cells per module. To ensure system safety and efficiency, each battery pack requires multiple AFEs (Automatic Factor Collectors) to acquire battery voltage. In this system, using the MP2796 AFE solution, typically four AFEs are used to acquire the voltage of each individual battery cell, such as... Figure 1 As shown.

[0003] In such high-voltage systems, the control signals for the AFE (Automatic External Wire) need to be implemented through multiple components. For example, the MCU requires four control signals to control the AFE's power-down sleep mode and IIC address allocation. Due to the high requirements for electrical isolation in 1500V systems, especially the creepage distance and clearance between the battery side and the MCU control side needing to strictly comply with safety regulations, isolation devices with ultra-wide-body characteristics must be selected. These isolation devices are used to achieve signal isolation to ensure safe communication between the high-voltage and low-voltage sides. However, ultra-wide-body isolation devices are more expensive, which puts pressure on the overall system cost.

[0004] Therefore, it is necessary to design a new circuit to achieve a low-cost power-down method, which can not only reduce hardware costs, but also effectively ensure the safety and stability of the system in high-voltage energy storage applications. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-cost power-down circuit for high-voltage systems based on MP2796.

[0006] To solve the above-mentioned technical problems, the purpose of this utility model is achieved through the following technical solution: providing a low-cost power-down circuit for a high-voltage system based on MP2796, including: a control unit, a plurality of AFE units, an ultra-wide body isolation optocoupler, and an isolation optocoupler; the control unit is connected to one of the AFE units by the ultra-wide body isolation optocoupler; among the plurality of AFE units, adjacent AFE units are connected by the isolation optocoupler.

[0007] The further technical solution includes an ultra-wide body IIC isolation chip, through which the control unit and several AFE units are connected.

[0008] The further technical solution is as follows: the control unit includes a GPIO module, which is connected to the ultra-widebody isolated optocoupler.

[0009] The further technical solution is as follows: the control unit also includes an IIC module, which is connected to the ultra-wide body IIC isolation chip.

[0010] The further technical solution is as follows: the model of the AFE unit is MP2796.

[0011] A further technical solution is that the number of isolation optocouplers is one less than the number of AFE units.

[0012] The further technical solution is as follows: the isolation optical coupler includes optical coupler UVM14, optical coupler UVM17 and optical coupler UVM18.

[0013] The further technical solution is as follows: the model of the ultra-wide body IIC isolation chip is Pai220N61-WWR.

[0014] The further technical solution is as follows: the ultra-wide body isolation optocoupler includes an ultra-wide body isolation optocoupler UVM13, and the model of the ultra-wide body isolation optocoupler UVM13 is HPL6W147C.

[0015] The further technical solution is that the number of ultra-wide body isolation optical couplers is one.

[0016] Compared with the prior art, the advantages of this utility model are as follows: This utility model uses an ultra-wide-body isolation optocoupler to communicate between the control unit and the AFE unit, and connects adjacent AFE units through ordinary isolation optocouplers, thereby realizing sequential control of activation and power-off one by one; this design reduces the isolation withstand voltage requirement, reduces the use of high-cost ultra-wide-body optocouplers, and effectively improves the safety and stability of the system, making it suitable for high-voltage energy storage applications. It reduces hardware costs and ensures the reliability of the system in high-voltage environments.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of a power-off circuit for a 1500V high-voltage system provided by existing technology;

[0020] Figure 2 A schematic diagram of a low-cost power-down circuit for a high-voltage system based on MP2796 provided for an embodiment of this utility model;

[0021] Figure 3 A detailed circuit diagram of a low-cost power-down circuit for a high-voltage system based on MP2796, provided for embodiments of this utility model;

[0022] Explanation of the markings in the image:

[0023] 10. Control unit; 20. AFE unit; 30. Ultra-wide body isolation optocoupler; 40. Isolation optocoupler; 50. Ultra-wide body IIC isolation chip. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0025] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0026] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] In a 1500V high-voltage energy storage system, multiple battery packs are connected in series. Each battery pack consists of multiple modules, and battery voltage is acquired through multiple AFEs (Automatic External Wires). Due to the stringent electrical isolation requirements of high-voltage systems, especially for secure communication between the battery side and the MCU control side, ultra-wide-body isolation devices are required to ensure signal isolation and comply with safety regulations. However, the higher cost of these isolation devices increases the overall system cost.

[0029] Therefore, this utility model provides a low-cost power-down circuit for high-voltage systems based on MP2796, which realizes a low-cost power-down method, not only reducing hardware costs, but also effectively ensuring the safety and stability of the system in high-voltage energy storage applications.

[0030] Specifically, this low-cost power-down circuit for high-voltage systems based on the MP2796 achieves effective circuit isolation and signal transmission by employing ultra-wide-body isolation optocouplers 30 and 40, while further enhancing the isolation between the control unit 10 and the AFE unit 20 through an ultra-wide-body IIC isolation chip 50. This circuit design simplifies the hardware structure, reduces the number of ultra-wide-body isolation optocouplers 30 used and the overall hardware cost, and ensures the safety and stability of the system through the collaborative operation of the GPIO and IIC modules in the control unit 10, particularly in high-voltage energy storage applications, achieving low-cost and efficient power-down protection.

[0031] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0032] Please see Figure 2 The low-cost power-down circuit for high-voltage systems based on MP2796 includes: a control unit 10, several AFE units 20, an ultra-wide body isolation optocoupler 30, and an isolation optocoupler 40; the control unit 10 is connected to one of the AFE units 20 via an ultra-wide body isolation optocoupler 30; among the several AFE units 20, adjacent AFE units 20 are connected via isolation optocouplers 40.

[0033] In this embodiment, the control unit is, but is not limited to, the model number KF32F330KQTT.

[0034] In this embodiment, the control unit 10 is the core of the entire high-voltage system. It controls the power-down and activation of each AFE unit 20 through the GPIO (General Purpose Input / Output) interface. The control unit 10 communicates with the first AFE unit 20 through ultra-widebody IIC isolation and configures the address of each AFE unit 20 as needed. It is also responsible for coordinating the working states of different AFE units 20 to ensure the orderly startup and shutdown process of the system.

[0035] AFE unit 20 is an analog front-end unit used to acquire high-voltage signals from the system. Each AFE unit 20 has a power-down control pin (NSHDN). The MCU starts or stops the operation of each AFE by controlling the power-down pin. The default I2C address of each AFE unit 20 is 00. After communicating with the MCU, the MCU will assign a unique address to each AFE unit 20 via the I2C protocol, such as 01, 02, 03, etc. Each AFE unit 20 communicates with the MCU or adjacent AFE units 20 in isolation via an ultra-wide-body isolation optocoupler 30.

[0036] The ultra-wide-body optocoupler is used for communication between the MCU and the first AFE unit 20. Its main function is to achieve electrical isolation of signals, preventing direct contact between high-voltage and low-voltage components and ensuring system safety. The ultra-wide-body isolation optocoupler 30 generally has a higher isolation voltage and better anti-interference capability, making it suitable for use in high-voltage systems.

[0037] Between multiple AFE units 20, adjacent AFE units 20 are connected via common optocouplers. These optocouplers provide basic electrical isolation, ensuring independence between adjacent units and reducing the required isolation withstand voltage. Therefore, the application of common optocouplers between adjacent AFE units 20 can significantly reduce costs.

[0038] The working principle and control process are as follows:

[0039] Power-on procedure: Control unit 10 activates the first AFE unit 20 by controlling its power-down pin (NSHDN1) via GPIO pins. When the first AFE unit 20 is activated, control unit 10 communicates with it via ultra-wide body IIC isolation optocoupler 40, with an initial communication address of 00. After successful communication, the MCU assigns it address 01.

[0040] Next, GPIOHV1 controls the power-down pin (NSHDN2) of the second AFE unit 20 to activate the second AFE unit 20. The control unit 10 communicates with the second AFE unit 20 through the ultra-wide body IIC isolation optocoupler 40, with an initial address of 00. After successful communication, the MCU sets the address to 02.

[0041] Similarly, the control unit 10 continues to control pins such as GPIOHV2 and GPIOHV3 to activate more AFE units 20. Each AFE unit 20 communicates with the MCU through an ultra-wide body IIC isolation optocoupler 40 and is set with its own unique address.

[0042] Power-down hibernation procedure: When the control unit 10 decides to shut down the system or enter a low-power mode, it will turn off the power to all AFE units 20 by pulling the NSHDN_MCU1 pin low. The specific operation is as follows:

[0043] Control unit 10 controls the power-down pin (NSHDN1) of the first AFE through the low level of NSDHN_MCU1, so that the first AFE unit 20 is powered down and stops working.

[0044] At the same time, GPIOHV1, GPIOHV2, GPIOHV3 and other pins control the corresponding power-down pin of AFE unit 20 to a low level, thereby turning off AFE unit 20 in sequence.

[0045] Each AFE unit 20 maintains communication with the next AFE unit 20 through an adjacent optocoupler, ensuring that the AFE units 20 throughout the system are in a low-power state.

[0046] This solution significantly reduces system cost by using standard optocouplers to connect multiple AFE units 20. Compared to the traditional solution that requires an ultra-widebody optocoupler for each AFE unit 20, this solution only requires one ultra-widebody optocoupler between the MCU and the first AFE unit 20, with the remaining units connected via standard optocouplers. For example, if the system requires eight AFE units 20 connected in series, the traditional solution requires eight ultra-widebody optocouplers, while the new solution only requires one ultra-widebody optocoupler and seven standard optocouplers. Thus, the cost reduction becomes even more significant as the number of AFE units 20 increases.

[0047] The circuit in this embodiment significantly reduces the overall system cost by rationally combining ultra-wide-body optocouplers and ordinary optocouplers, especially when the number of AFE units 20 is large. Using ultra-wide-body optocouplers to achieve isolated communication between the control unit 10 and the first AFE ensures stable signal transmission while protecting the control unit 10 and AFE units 20 from interference from high-voltage components. The entire system has high anti-interference capability and electrical isolation. Using ordinary optocouplers to connect adjacent AFE units 20 reduces the system's isolation withstand voltage requirements, simplifying the circuit design and making it easier to implement. This design supports the series connection of more AFE units 20, making it suitable for larger-scale high-voltage systems, and due to its low-cost design, expanding to more units does not significantly increase costs.

[0048] The 1500V high-voltage power-down circuit based on MP2796 can significantly reduce system costs while meeting electrical isolation and safety requirements. The adoption of a reasonable configuration of isolation optocouplers and a power-down control strategy makes the entire system more economical and efficient, with good stability and scalability.

[0049] In one embodiment, please refer to Figure 2The aforementioned low-cost power-down circuit for a high-voltage system based on MP2796 is characterized by further including an ultra-wide body IIC isolation chip 50, through which the control unit 10 and several AFE units 20 are connected.

[0050] In this embodiment, the ultra-wide body IIC isolation chip 50 is used to provide isolation between the control unit 10 and multiple AFE units 20, ensuring the stability and security of data transmission and preventing high-voltage signals from affecting the low-voltage control section.

[0051] In one embodiment, please refer to Figure 2 The aforementioned control unit 10 includes a GPIO module, which is connected to an ultra-wide body isolation optocoupler 30. The GPIO module manages the power-down control or operating state of multiple AFE units 20 through control signals. The combination of the GPIO module and the optocoupler effectively isolates the high-voltage section from the low-voltage control unit 10, ensuring system safety.

[0052] In one embodiment, please refer to Figure 2 The control unit 10 also includes an IIC module, which is connected to the ultra-wide body IIC isolation chip 50. The IIC module is responsible for communicating with the AFE unit 20 via the IIC protocol, ensuring that the control unit 10 can configure and control the operating status of multiple AFE units 20 as needed.

[0053] In one embodiment, please refer to Figure 3 The aforementioned AFE unit 20 is model MP2796. The MP2796 processes high-voltage current signals in this type of AFE unit 20, performing corresponding conversions and controls to ensure stable system operation under high-voltage conditions.

[0054] In one embodiment, please refer to Figures 2 to 3 The number of isolation optocouplers 40 mentioned above is one less than the number of AFE units 20.

[0055] In one embodiment, please refer to Figures 2 to 3 The number of the aforementioned ultra-wide body isolation optical couplers 30 is one.

[0056] In one embodiment, please refer to Figure 3 The aforementioned isolation optical coupler 40 includes optical coupler UVM14, optical coupler UVM17, and optical coupler UVM18.

[0057] In one embodiment, please refer to Figure 3 The aforementioned ultra-wide body IIC isolation chip 50 is model number Pai220N61-WWR.

[0058] In one embodiment, please refer to Figure 3The aforementioned ultra-wide body isolated optocoupler 30 includes ultra-wide body isolated optocoupler 30UVM13, the model of which is HPL6W147C.

[0059] The circuit in this embodiment controls the power-down sequence of multiple AFE (Analog Front End) modules to achieve a design with lower isolation requirements and lower cost. The specific process is as follows:

[0060] Power failure control:

[0061] The system controls the power-down pins (NSHDN1, NSHDN2, NSHDN3, NSHDN4) of each AFE unit 20 through the control unit 10, thereby activating each AFE unit 20 one by one.

[0062] The control unit 10 communicates with the first AFE unit 20 via an ultra-wide body IIC chip isolation system, with a default address of 00. After successful communication, its address is set to 01. Then, the first AFE unit 20 enables the second AFE unit 20 by controlling its power-down pin via I / O. The control unit 10 then communicates with the second AFE unit 20 via the same ultra-wide body IIC isolation system, with its address set to 02. This process is repeated, and multiple AFE units 20 are connected in series in this manner.

[0063] The AFE units 20 are isolated from each other via optocouplers (including ultra-wide-body optocouplers and standard optocouplers). In this way, the system reduces the isolation withstand voltage requirement, uses fewer ultra-wide-body optocouplers and standard optocouplers, and reduces costs.

[0064] This type of circuit is low-cost and simple to design. It has lower isolation voltage requirements, so replacing some high-cost ultra-wide-body optocouplers with ordinary optocouplers further reduces costs. It also improves system stability and reliability.

[0065] Power-on steps:

[0066] The control unit 10 first activates the first AFE unit 20 by controlling NSHDN_MCU1 with a high level. The control unit 10 then communicates with the AFE in ultra-wide body IIC isolation and sets the address.

[0067] Subsequently, the control unit 10 enables other AFE units 20 in sequence through GPIO pins and control signals. Each AFE communicates in isolation through an optocoupler and sets its own address.

[0068] Power-off hibernation steps:

[0069] When it is necessary to enter the power-down mode, the control unit 10 sets NSHDN_MCU1 to a low level, enables the power-down pins of each AFE one by one, shuts down the operation of all AFE units 20, and enters a low-power state.

[0070] In summary, this low-cost power-down method allows the system to reduce costs more effectively while maintaining system stability and reliability.

[0071] Please see Figure 3 In the diagram, GPIOHV1, GPIOHV2, and GPIOHV3 serve as the I / O interfaces for AFE1, AFE2, and AFE3, respectively. NSHDN1, NSHDN2, NSHDN3, and NSHDN4 are the power-down control pins for AFE1, AFE2, AFE3, and AFE4, respectively. A low level disables AFE1, while a high level enables normal operation. NSHDN_MCU1 is the I / O pin for control unit 10, used to control NSHDN1. RVM179, RVM180, RVM181, and RVM182 are resistors used for current limiting and protection. CVM54, CVM55, CVM56, and CVM57 are capacitors used for filtering and energy storage. DVM36, DVM37, DVM38, and DVM39 are diodes used to protect the circuit from reverse voltage. EL817S1 is an optocoupler used for signal isolation. QQVM4, QQVM5, and QQVM6 are transistors used for signal amplification and switching control. VCC_MP is the main power input. GND is the ground terminal. VBAT1, VBAT2, VBAT3, and VBAT4 are battery power supply terminals.

[0072] Power-on steps

[0073] NSHDN_MCU1 high level: Enables NSHDN1, activates AFE1 and enables normal operation. The MCU communicates with AFE1 through UVM11 ultra-wide body IIC isolation, with the default address being 00. After successful communication, the AFE1 address is set to 01.

[0074] GPIOHV1 high level: Enables NSHDN2, AFE2 is activated and works normally. The MCU communicates with AFE2 through UVM12 ultra-wide body IIC isolation, the default address is 00, and after successful communication, the AFE2 address is set to 02.

[0075] GPIOHV2 high level: Enables NSHDN3, AFE3 is activated and works normally. The MCU communicates with AFE3 through UVM15 ultra-wide body IIC isolation, the default address is 00, and after successful communication, the AFE3 address is set to 03.

[0076] GPIOHV3 high level: Enables NSHDN4, AFE4 is activated and works normally. The MCU communicates with AFE4 through UVM16 ultra-wide body IIC isolation, the default address is 00, and after successful communication, the AFE4 address is set to 04.

[0077] Power-off hibernation steps:

[0078] The MCU sets NSHDN_MCU1 to a low level, which in turn sets NSHDN1, NSHDN2, NSHDN3, and NSHDN4 to a low level in sequence, causing AFE1 to AFE4 to power down and stop working, and sets GPIOHV1, GPIOHV2, and GPIOHV3 to a low level.

[0079] UVM11, UVM12, UVM15, and UVM16 are ultra-wide body IIC isolation chips 50, used for data transmission between the MCU and AFE to ensure electrical isolation.

[0080] UVM13, UVM14, UVM17, and UVM18 are general-purpose optocoupler isolation devices used for the isolation and transmission of other signals.

[0081] This circuit design achieves electrical isolation and data transmission between the control unit 10 and multiple AFE units 20 through multiple optocouplers, while utilizing GPIOHV and NSHDN control signals to achieve independent control and management of each AFE. This design improves system reliability and security, and is suitable for applications requiring multi-channel data acquisition and processing. It offers advantages such as low cost, simple circuitry, reduced isolation withstand voltage requirements, high stability, and high reliability.

[0082] The aforementioned low-cost power-down circuit for high-voltage systems based on the MP2796 communicates between the control unit 10 and the AFE unit 20 using an ultra-wide-body isolation optocoupler 30, while adjacent AFE units 20 are connected via ordinary isolation optocouplers 40, thereby achieving sequential control of activation and power-down. This design reduces the isolation withstand voltage requirements and the use of high-cost ultra-wide-body optocouplers, while effectively improving the safety and stability of the system. It is suitable for high-voltage energy storage applications, reducing hardware costs while ensuring the reliability of the system in high-voltage environments.

[0083] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A low-cost power-down circuit for high-voltage systems based on MP2796, characterized in that, include: The control unit comprises a plurality of AFE units, an ultra-wide body isolation optocoupler, and an isolation optocoupler; the control unit is connected to one of the AFE units via the ultra-wide body isolation optocoupler; among the plurality of AFE units, adjacent AFE units are connected via the isolation optocoupler.

2. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 1, characterized in that, It also includes an ultra-wide body IIC isolation chip, through which the control unit and several AFE units are connected.

3. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 1, characterized in that, The control unit includes a GPIO module, which is connected to the ultra-widebody isolated optocoupler.

4. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 2, characterized in that, The control unit also includes an IIC module, which is connected to the ultra-wide body IIC isolation chip.

5. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 1, characterized in that, The AFE unit is model MP2796.

6. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 1, characterized in that, The number of isolation optocouplers is one less than the number of AFE units.

7. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 1, characterized in that, The isolation optocouplers include optocoupler UVM14, optocoupler UVM17, and optocoupler UVM18.

8. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 2, characterized in that, The model number of the ultra-wide body IIC isolation chip is Pai220N61-WWR.

9. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 1, characterized in that, The ultra-wide body isolation optocoupler includes an ultra-wide body isolation optocoupler UVM13, the model of which is HPL6W147C.

10. The low-cost power-down circuit for high-voltage systems based on MP2796 according to claim 1, characterized in that, The number of ultra-wide body isolation optical couplers is one.

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