Power-off bleeder circuit, battery master control unit and battery management system
By designing a power-off discharge circuit in the battery management system, the residual voltage of the energy storage device is quickly released using the power-off detection module and the discharge module, which solves the problem of chaotic power-on timing of the control chip caused by rapid plugging and unplugging operations and ensures system stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN TOPBAND CO LTD
- Filing Date
- 2025-06-04
- Publication Date
- 2026-06-09
Smart Images
Figure CN224343091U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage system technology, and in particular to a power failure discharge circuit, a battery control unit, and a battery management system. Background Technology
[0002] As the global energy structure shifts towards renewable energy, the Battery Management System (BMS), as the core control system of modern energy storage technology, plays an irreplaceable role in ensuring battery safety, improving efficiency, and extending battery life.
[0003] Modern battery management systems typically employ a layered architecture, such as a three-layer architecture containing a slave control unit (BMU), a master control unit (BCU), and a master control unit (BAU). All of these units utilize capacitive components. In certain application scenarios, rapid plugging and unplugging operations, where the power supply is suddenly disconnected and quickly restored, can lead to a short time interval between power loss and restoration. During this brief interval, the energy stored in the internal energy storage devices cannot be released quickly, resulting in residual voltage. This residual voltage can easily cause power timing disruptions during the power restoration phase.
[0004] However, the control chips contained in the aforementioned units, such as the main control unit (BAU), have strict power-on timing requirements. If the power-on timing is not strictly followed, it may cause the chip to fail to start, crash, program to malfunction, or even program to crash, which will seriously affect the normal operation of the system. Utility Model Content
[0005] Therefore, it is necessary to provide a power-off discharge circuit, a battery control unit, and a battery management system to address the problem that the power-on timing of the control chip is disordered when the time interval between power failure and power-on is short.
[0006] A power-off discharge circuit, the power-off discharge circuit comprising:
[0007] Power input terminal, used to connect to an external power source;
[0008] The power supply output terminal connected to the energy storage device is used to output the power supply voltage to the load;
[0009] A power failure detection module, wherein the input terminal of the power failure detection module is connected to the power supply input terminal, and the output terminal of the power failure detection module is used to provide feedback on the power supply status of the external power supply;
[0010] The first control module is connected to the output of the power failure detection module. The first control module is triggered to conduct when the power supply of the external power source is in a power failure state.
[0011] The first discharge module has its controlled terminal connected to the output terminal of the first control module, its first terminal connected to the power supply output terminal, and its second terminal grounded. The first discharge module is used to discharge the energy storage device connected to the power supply output terminal when the first control module is turned on.
[0012] In one embodiment, the power failure detection module includes a current limiting protection unit and an optocoupler isolation unit. The input terminal of the current limiting protection unit is connected to the power supply input terminal, the output terminal of the current limiting protection unit is connected to the input terminal of the optocoupler isolation unit, and the output terminal of the optocoupler isolation unit is connected to the controlled terminal of the first control module.
[0013] In one embodiment, the power supply input terminal includes a positive power supply terminal and a negative power supply terminal, and the current limiting protection unit includes a first resistor, a second resistor and a first diode. The positive power supply terminal is connected to the cathode of the first diode through the first resistor, and the negative power supply terminal is connected to the anode of the first diode through the second resistor. The cathode and anode of the first diode also serve as the output terminals of the current limiting protection unit.
[0014] In one embodiment, the optocoupler isolation unit includes an optocoupler, the anode of which is connected to the cathode of the first diode, the cathode of which is connected to the anode of the first diode, the collector of which is used to provide feedback on the power supply status of the external power source, and the emitter of which is grounded.
[0015] In one embodiment, the controlled end of the first control module is also connected to the power supply output end;
[0016] When the external power supply is in a power-off state, the output terminal of the optocoupler isolation unit is in a cut-off state, and the first control module is triggered to conduct by the power supply voltage of the power supply output terminal;
[0017] When the external power supply is in a normal power supply state, the controlled terminal of the first control module is grounded through the output terminal of the optocoupler isolation unit, and the first control module remains in a cut-off state.
[0018] In one embodiment, the first control module includes a first switch, a third resistor, a fourth resistor, and a fifth resistor. The base of the first switch is connected to the output terminal of the optocoupler isolation unit through the third resistor. The base of the first switch is also connected to the power supply output terminal through the third resistor and the fourth resistor in sequence. The collector of the first switch is connected to the power supply output terminal through the fifth resistor. The collector of the first switch serves as the output terminal of the first control module, and the emitter of the first switch is grounded.
[0019] In one embodiment, the power supply output terminal includes a first power supply output terminal and a second power supply output terminal that output different voltage levels;
[0020] The controlled terminal of the first discharge module is connected to the output terminal of the first control module, the first terminal of the first discharge module is connected to the first power supply output terminal, and the second terminal of the first discharge module is grounded. The first discharge module is used to discharge the energy storage device connected to the first power supply output terminal when the first control module is turned on.
[0021] The power-off discharge circuit further includes: a second discharge module;
[0022] The controlled terminal of the second discharge module is connected to the output terminal of the first control module, the first terminal of the second discharge module is connected to the second power supply output terminal, and the second terminal of the second discharge module is grounded. The second discharge module is used to discharge the energy storage device connected to the second power supply output terminal when the first control module is turned on.
[0023] In one embodiment, the power supply output terminal includes a first power supply output terminal and a second power supply output terminal that output different voltage levels;
[0024] The controlled terminal of the first discharge module is connected to the output terminal of the first control module, the first terminal of the first discharge module is connected to the first power supply output terminal, and the second terminal of the first discharge module is grounded. The first discharge module is used to discharge the energy storage device connected to the first power supply output terminal when the first control module is turned on.
[0025] The power-off discharge circuit further includes: a second control module and a second discharge module;
[0026] The first end of the second control module is connected to the first power supply output terminal, the second end of the second control module is grounded, the control terminal of the second control module is connected to the controlled terminal of the second discharge module, the first end of the second discharge module is connected to the second power supply output terminal, the second end of the second discharge module is grounded, and the second discharge module is used to discharge the energy storage device connected to the second power supply output terminal when the first power supply output terminal completes the discharge.
[0027] In one embodiment, the first discharge module includes a first MOSFET, a first resistor assembly, and a sixth resistor. The gate of the first MOSFET is connected to the output terminal of the first control module through the sixth resistor. The source of the first MOSFET is connected to the first power supply output terminal. The drain of the first MOSFET is grounded through the first resistor assembly.
[0028] In one embodiment, the second discharge module includes a second MOSFET, a second resistor assembly, and a seventh resistor. The gate of the second MOSFET is connected to the output terminal of the first control module through the seventh resistor. The source of the second MOSFET is connected to the second power supply output terminal. The drain of the second MOSFET is grounded through the second resistor assembly.
[0029] In one embodiment, the second control module includes an eighth resistor and a ninth resistor. The eighth resistor and the ninth resistor are connected in series, with the first end serving as the first end of the second control module, the second end serving as the second end of the second control module, and the common end serving as the control end of the second control module.
[0030] In one embodiment, the second discharge module includes a second MOSFET and a second resistor assembly. The gate of the second MOSFET is connected to the control terminal of the second control module, the source of the second MOSFET is connected to the second power supply output terminal, and the drain of the second MOSFET is grounded through the second resistor assembly.
[0031] A battery control unit includes a control chip, a power conversion device, and a power-off discharge circuit as described above.
[0032] The power conversion device is connected to an external power source through the power input terminal, performs voltage conversion to obtain the power supply voltage, and outputs it to the control chip through the power output terminal to supply power.
[0033] The power-off discharge circuit is used to discharge the energy storage device connected to the power supply output terminal when the external power supply is in a power-off state.
[0034] A battery management system includes a battery control unit as described above.
[0035] The aforementioned power-off discharge circuit, battery control unit, and battery management system are connected to the power supply input terminal of the power-off detection module to provide feedback on the power supply status of the external power source. The controlled terminal of the first control module is then connected to the output terminal of the power-off detection module, triggering the first control module to conduct when the external power supply is in a power-off state. The controlled terminal of the first discharge module is connected to the output terminal of the first control module, its first terminal is connected to the power supply output terminal, and its second terminal is grounded. This discharges the energy storage device connected to the power supply output terminal when the first control module is on. Through this design, discharge occurs after power failure, quickly releasing the residual voltage of the internal energy storage device. This improves the situation where the power-on timing of the powered control chip is disordered when the time interval between power failure and power-on is short. Attached Figure Description
[0036] Figure 1 This is a schematic diagram of a system block diagram of a power-off discharge circuit in one embodiment;
[0037] Figure 2 This is a schematic diagram of the circuit structure of the power-off discharge circuit in one embodiment;
[0038] Figure 3 This is a schematic diagram of the circuit structure of the power-off discharge circuit in another embodiment;
[0039] Figure 4 This is a schematic diagram of the circuit structure of the power-off discharge circuit in another embodiment;
[0040] Figure 5 This is a schematic diagram of the system block of the battery control unit in one embodiment.
[0041] Explanation of reference numerals in the attached figures:
[0042] The system includes a power failure detection module 110, a first control module 120, a first discharge module 130, a first resistor assembly 131, a second discharge module 140, a second resistor assembly 141, a second control module 150, a control chip 10, a power conversion device 20, and a power failure discharge circuit 30. Detailed Implementation
[0043] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0045] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0046] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.
[0047] In the description of the embodiments of this application, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. For example, in the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., transmit electrical signals or data to each other. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.
[0048] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.
[0049] In one exemplary embodiment, such as Figure 1As shown, a power-off discharge circuit is provided, including: a power supply input terminal Vin for connecting to an external power source; a power supply output terminal Vout connected to an energy storage device for outputting a power supply voltage to a load; a power-off detection module 110, the input terminal of which is connected to the power supply input terminal Vin, and the output terminal of which is used to feedback the power supply status of the external power source; a first control module 120, the controlled terminal of which is connected to the output terminal of the power-off detection module 110, and the first control module 120 is triggered to conduct when the power supply status of the external power source is in a power-off state; and a first discharge module 130, the controlled terminal of which is connected to the output terminal of the first control module 120, the first terminal of which is connected to the power supply output terminal Vout, and the second terminal of which is grounded, and the first discharge module 130 is used to discharge the energy storage device connected to the power supply output terminal Vout when the first control module 120 is turned on.
[0050] The power input terminal Vin and the power output terminal Vout can be equipped with power conversion devices to convert the external power supply connected to the power input terminal Vin into a power supply voltage that matches the power supply requirements of the load, and then output the power supply to the load through the power output terminal Vout.
[0051] It should be noted that the power output terminal Vout is connected to an energy storage device, whose rapid charging and discharging characteristics can be used to optimize the stability and response speed of the power supply system. For example, in scenarios where power is supplied to a control chip, the switching action of its internal transistors generates high-frequency transient currents, causing power supply voltage fluctuations. In this case, the energy storage device absorbs these high-frequency noises through a low-impedance path, preventing noise from coupling to the power supply pins and affecting the normal operation of the power supply side.
[0052] However, as is known from the background technology, in certain application scenarios, during rapid power-on and power-off operations, when the power supply is suddenly disconnected and quickly restored, the energy stored in the energy storage device connected to the power output terminal Vout cannot be released quickly, leaving a certain residual voltage. During the power-on phase, this residual voltage can easily cause the control chip to fail to start, freeze, malfunction, or even crash. Therefore, the power-off discharge circuit provided in this application can be used to quickly release the residual voltage of the internal energy storage device, thereby improving the situation where the power-on timing of the powered control chip is disordered when the time interval between power-off and power-on is short.
[0053] Specifically, the input terminal of the power failure detection module 110 is connected to the power supply input terminal Vin, and is used to detect the power supply status of the external power supply, sensing in real time whether the external power supply is in a power failure state. The power failure detection module 110 can achieve detection through a voltage threshold comparison method, using a comparator or dedicated chip (such as TLV7011, TLVx172, etc.) to monitor the power supply voltage in real time, and triggering a signal output when the voltage is lower than a preset threshold. Alternatively, the power failure detection module 110 can achieve detection through a current detection method, using a current sensor (such as INA293) to monitor the supply current, and triggering a signal output if the current is abnormal. The power failure detection module 110 can also utilize the electrical isolation characteristics of an optocoupler to safely and quickly detect the power supply status, avoiding the impact of high-voltage circuits on low-voltage detection circuits and ensuring system safety.
[0054] In some examples, the power supply status of the external power supply fed back by the output terminal of the power failure detection module 110 can be either a power failure state or a normal power supply state.
[0055] Furthermore, the controlled terminal of the first control module 120 is connected to the output terminal of the power-down detection module 110, and is triggered to conduct when the external power supply is in a power-down state. The first control module 120 can be implemented using a switching circuit, with the controlled terminal of the switching element serving as the controlled terminal of the first control module 120. The type of switching element can be designed to trigger the switching element to conduct when the external power supply is in a power-down state. In this embodiment, the switching element can be implemented using semiconductor switches (Solid-State Switches), such as transistors (BJT / MOSFET / IGBT), thyristors, and solid-state relays (SSRs).
[0056] Furthermore, the first discharge module 130 is the main circuit structure for rapidly releasing the residual voltage of the internal energy storage device. Its first terminal is connected to the power supply output terminal Vout, and its second terminal is grounded. Simultaneously, the controlled terminal of the first discharge module 130 is connected to the output terminal of the first control module 120. When the first control module 120 is turned on, it can discharge the energy storage device connected to the power supply output terminal Vout by grounding it, thereby rapidly releasing the residual voltage of the energy storage device.
[0057] In some examples, the first discharge module 130 can discharge using a resistive dummy load, or it can discharge using an active switch (transistor / relay), or it can discharge by forming a freewheeling circuit with a diode and a resistor, or it can be other combinations, as long as it can achieve voltage discharge of the energy storage device.
[0058] The aforementioned power-off discharge circuit connects the input terminal of the power-off detection module to the power supply input terminal to provide feedback on the power supply status of the external power source. Then, the controlled terminal of the first control module is connected to the output terminal of the power-off detection module, triggering the first control module to conduct when the external power supply is in a power-off state. The controlled terminal of the first discharge module is connected to the output terminal of the first control module, its first terminal is connected to the power supply output terminal, and its second terminal is grounded. This discharges the energy storage device connected to the power supply output terminal when the first control module is on. Through this design, discharge occurs after power failure, quickly releasing the residual voltage of the internal energy storage device. This improves the situation where the power-on timing of the powered control chip is disordered when the time interval between power failure and power-on is short.
[0059] In one exemplary embodiment, such as Figure 2 As shown, the power failure detection module 110 includes a current limiting protection unit 111 and an optocoupler isolation unit 112. The input terminal of the current limiting protection unit 111 is connected to the power supply input terminal Vin, the output terminal of the current limiting protection unit 111 is connected to the input terminal of the optocoupler isolation unit 112, and the output terminal of the optocoupler isolation unit 112 is connected to the controlled terminal of the first control module 120.
[0060] Specifically, the input terminal of the current limiting protection unit 111 is connected to the power supply input terminal Vin. As a protection means set in the power-off discharge circuit provided in this application, it can ensure circuit safety by limiting the current direction and blocking the reverse current.
[0061] In one exemplary embodiment, continuing with reference to Figure 2 The power input terminal Vin includes a positive power supply terminal Vin+ and a negative power supply terminal Vin-. The current limiting protection unit 111 includes a first resistor R1, a second resistor R2 and a first diode D1. The positive power supply terminal Vin+ is connected to the cathode of the first diode D1 through the first resistor R1, and the negative power supply terminal Vin- is connected to the anode of the first diode D1 through the second resistor R2. The cathode and anode of the first diode D1 also serve as the output terminals of the current limiting protection unit 111.
[0062] Specifically, the current limiting protection unit 111 limits the loop current through a series resistor to prevent the current from exceeding the rated value of the load or power supply. The resistor also absorbs some power, reducing the voltage / current stress on the downstream connection circuit. In this example, the first resistor R1 and the second resistor R2 are connected to the positive power supply terminal Vin+ and the negative power supply terminal Vin-, respectively, to limit the discharge current at the power supply input terminal Vin.
[0063] The resistance values of the first resistor R1 and the second resistor R2 are not limited and can be set according to the supply voltage of the external power supply connected to the power input terminal Vin. Resistors with sufficient power should be selected (e.g., when limiting the current to 1A, a 1Ω resistor needs to have at least 1W of power). This embodiment uses a series resistor for current limiting, which is simple, low-cost, and passively reliable.
[0064] Furthermore, the current limiting protection unit 111 utilizes the unidirectional conductivity of the diode element to block the reverse current. At the same time, the cathode and anode of the first diode D1 are used as the output terminals of the current limiting protection unit 111. That is, the first diode D1 is connected in parallel across the input side of the optocoupler isolation unit 112, which can achieve the purpose of absorbing back electromotive force. The advantages are no power consumption, fast response (ns level) and no need for control circuit.
[0065] In one example, continue to refer to Figure 2 The current limiting protection unit 111 may also include a filter capacitor C1, which is connected in parallel between the cathode and anode of the first diode D1. Through its charging and discharging characteristics, the filter capacitor C1 "absorbs" or "releases" charge, maintains the voltage stability of the external power input, and filters out interference signals, thereby improving power quality and suppressing noise.
[0066] In one exemplary embodiment, continuing with reference to Figure 2 The optocoupler isolation unit 112 includes an optocoupler U1. The anode of the optocoupler U1 is connected to the cathode of the first diode D1, the cathode of the optocoupler U1 is connected to the anode of the first diode D1, the collector of the optocoupler U1 is used to provide feedback on the power supply status of the external power supply, and the emitter of the optocoupler U1 is grounded.
[0067] Among them, the optocoupler U1 is a semiconductor device that achieves electrical isolation through optical signals. It converts the electrical signal at the input end into an optical signal and then restores it to an electrical signal at the output end, thereby isolating high and low voltage circuits.
[0068] Specifically, the optocoupler U1 may include a light-emitting diode on the input side and a photosensitive element on the output side. The photosensitive element may be, for example, a phototransistor, a photodiode, or a photosensitive silicon controlled rectifier (SCR). In this embodiment, the output side of the optocoupler U1 is implemented using a phototransistor.
[0069] In one example, continue to refer to Figure 2 The anode of the light-emitting diode on the input side of the optocoupler U1 is connected to the cathode of the first diode D1, the cathode of the light-emitting diode on the input side of the optocoupler U1 is connected to the anode of the first diode D1, the collector of the phototransistor on the output side of the optocoupler U1 is used to provide feedback on the power supply status of the external power supply, and the emitter of the phototransistor on the output side of the optocoupler U1 is grounded.
[0070] This application utilizes the LED on the input side of the optocoupler U1 to sense the power supply status of the external power source. When the external power supply is in a normal power supply state, the voltage applied through the current limiting protection unit 111 powers the LED, causing it to light up normally. However, when the external power supply is in a power-off state, the voltage applied through the current limiting protection unit 111 drops rapidly, and the input voltage is insufficient to power the LED. Furthermore, the power supply status of the external power source is fed back through the phototransistor on the output side of the optocoupler U1. When the input LED lights up due to voltage, the output phototransistor conducts, and the collector is connected to ground via the emitter, indicating that the external power supply status is normal. When the input LED does not light up due to power failure and lack of voltage input, the collector of the output phototransistor is cut off, indicating that the external power supply status is power-off.
[0071] In this embodiment, a transparent insulating material (such as silicone or an air gap) can be used as an isolation medium between the input side and the output side of the optocoupler U1. Since there is no electrical connection between the input side and the output side, and the signal is transmitted only through light, the impact of the high-voltage circuit on the low-voltage detection circuit can be avoided, thus ensuring safety.
[0072] In one exemplary embodiment, continuing with reference to Figure 2 The controlled terminal of the first control module 120 is also connected to the power supply output terminal Vout. When the external power supply is in a power-off state, the output terminal of the optocoupler isolation unit 112 is in a cut-off state, and the first control module 120 is triggered to conduct by the power supply voltage of the power supply output terminal Vout; when the external power supply is in a normal power supply state, the controlled terminal of the first control module 120 is grounded through the output terminal of the optocoupler isolation unit 112, and the first control module 120 remains in a cut-off state.
[0073] This can be understood as follows: when the external power supply is in a power-off state, the collector of the phototransistor on the output side of the optocoupler isolation unit 112 is in a cutoff state. However, due to the influence of the internal energy storage device, the power supply output terminal Vout still has a residual supply voltage, which can trigger the first control module 120 to conduct by the supply voltage of the power supply output terminal Vout. When the external power supply is in a normal power supply state, the controlled terminal of the first control module 120 is connected to ground through the collector and emitter of the phototransistor, maintaining a cutoff state. This prevents the first discharge module 130 from conducting, and thus, when the external power supply is in a normal power supply state, the first discharge module 130 remains in a state of not consuming power, preventing leakage current problems and reducing the overall energy consumption of the device.
[0074] In one exemplary embodiment, continuing with reference to Figure 2The first control module 120 includes a first switch Q1, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The base of the first switch Q1 is connected to the output terminal of the optocoupler isolation unit 112 through the third resistor R3. The base of the first switch Q1 is also connected to the power supply output terminal Vout through the third resistor R3 and the fourth resistor R4 in sequence. The collector of the first switch Q1 is connected to the power supply output terminal Vout through the fifth resistor R5. The collector of the first switch Q1 serves as the output terminal of the first control module 120, and the emitter of the first switch Q1 is grounded.
[0075] Specifically, the base of the first switching transistor Q1 is connected to the collector of the output phototransistor of the optocoupler isolation unit 112 via the third resistor R3. This can be understood as follows: when the external power supply is in a power-off state, the collector of the phototransistor is in a cutoff state, and the first switching transistor Q1 is triggered to conduct by the residual supply voltage at the power supply output terminal Vout. When the external power supply is in a normal power supply state, the first switching transistor Q1 is connected to ground via the collector and emitter of the phototransistor, remaining in a cutoff state.
[0076] Among them, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 all serve to limit current.
[0077] In one exemplary embodiment, continuing with reference to Figure 2 The first discharge module 130 includes a first MOSFET Q2, a first resistor assembly 131 and a sixth resistor R6. The gate of the first MOSFET Q2 is connected to the output terminal of the first control module 120 through the sixth resistor R6. The source of the first MOSFET Q2 is connected to the power supply output terminal Vout. The drain of the first MOSFET Q2 is grounded through the first resistor assembly 131.
[0078] The first resistor assembly 131 can consist of multiple resistors connected in parallel to accelerate the discharge of residual voltage at the power supply output terminal Vout. The number and resistance values of the resistors connected in parallel in the first resistor assembly 131 are not limited and can be determined based on the level of residual voltage to be discharged, i.e., based on the capacity of the energy storage device connected to the power supply output terminal Vout. In this embodiment, the explanation is based on the example of the first resistor assembly 131 including two resistors connected in parallel, namely, the first resistor assembly 131 includes resistors R10 and R11 connected in parallel.
[0079] Specifically, the gate of the first MOSFET Q2 is connected to the collector of the first switch Q1 through the sixth resistor R6, the source of the first MOSFET Q2 is connected to the power supply output terminal Vout, and the drain of the first MOSFET Q2 is grounded through parallel resistors R10 and R11. When the external power supply is in a power-off state, the first switch Q1 is triggered to conduct by the residual power supply voltage at the power supply output terminal Vout. Consequently, the first MOSFET Q2 is triggered to conduct due to the conduction of the first switch Q1, causing the residual voltage of the energy storage device connected to the power supply output terminal Vout to discharge through the first MOSFET Q2 and the first resistor assembly 131 to ground.
[0080] In this embodiment, a MOSFET is used to conduct the residual voltage at the power output terminal Vout, and the series resistor component serves as a dummy load to prevent the power supply from directly connecting to ground through the resistor. This avoids the problem of excessive inrush current burning out components at the moment of power-on, while also achieving the functions of charge discharge, oscillation suppression, and drive protection.
[0081] In one exemplary embodiment, such as Figure 3 As shown, the power supply output terminal Vout includes a first power supply output terminal Vout1 and a second power supply output terminal Vout2 that output different voltage levels.
[0082] It is understandable that when supplying power to a load, the power conversion device can match different voltage levels to the output voltage based on the different power supply requirements of the load. For example, the first power supply output terminal Vout1 can be used to convert the output voltage to 5V, and the second power supply output terminal Vout2 can be used to convert the output voltage to 3.3V.
[0083] In one example, continue to refer to Figure 3 The controlled terminal of the first discharge module 130 is connected to the output terminal of the first control module 120. The first terminal of the first discharge module 130 is connected to the first power supply output terminal Vout1. The second terminal of the first discharge module 130 is grounded. The first discharge module 130 is used to discharge the energy storage device connected to the first power supply output terminal Vout1 when the first control module 120 is turned on.
[0084] Furthermore, the power-off discharge circuit also includes a second discharge module 140. The controlled terminal of the second discharge module 140 is connected to the output terminal of the first control module 120, the first terminal of the second discharge module 140 is connected to the second power supply output terminal Vout2, and the second terminal of the second discharge module 140 is grounded. The second discharge module 140 is used to discharge the energy storage device connected to the second power supply output terminal Vout2 when the first control module 120 is turned on.
[0085] It can be understood that, in the case where the power conversion device is matched with different voltage levels of power supply voltage, by setting the first discharge module 130 and the second discharge module 140, the residual voltage of the energy storage device connected to the power supply output terminal Vout of different voltage levels can be discharged respectively.
[0086] In one example, continue to refer to Figure 3 The first discharge module 130 includes a first MOSFET Q2, a first resistor assembly 131 and a sixth resistor R6. The gate of the first MOSFET Q2 is connected to the collector of the first switching transistor Q1 through the sixth resistor R6. The source of the first MOSFET Q2 is connected to the first power supply output terminal Vout1. The drain of the first MOSFET is grounded through the first resistor assembly 131.
[0087] Continue to refer to Figure 3 The second discharge module 140 includes a second MOSFET Q3, a second resistor assembly 141 and a seventh resistor R7. The gate of the second MOSFET Q3 is connected to the collector of the first switching transistor Q1 through the seventh resistor R7. The source of the second MOSFET Q3 is connected to the second power supply output terminal Vout2. The drain of the second MOSFET Q3 is grounded through the second resistor assembly 141.
[0088] Referring to the description of the first resistor assembly 131 above, it can be a plurality of resistor elements connected in parallel, such as resistors R10 and R11 connected in parallel, to accelerate the discharge of residual voltage at the first power supply output terminal Vout1. The second resistor assembly 141 can also be a plurality of resistor elements connected in parallel, such as resistors R12 and R13 connected in parallel, to accelerate the discharge of residual voltage at the second power supply output terminal Vout2.
[0089] Specifically, when the external power supply is in a power-off state, the first switch Q1 is triggered to turn on by the residual supply voltage at the first power supply output terminal Vout1. Consequently, the first MOSFET Q2 is triggered to turn on due to the conduction of the first switch Q1, causing the residual voltage of the energy storage device connected to the first power supply output terminal Vout1 to discharge through the first MOSFET Q2 and the first resistor assembly 131 to ground. The second MOSFET Q3 is triggered to turn on due to the conduction of the first switch Q1, causing the residual voltage of the energy storage device connected to the second power supply output terminal Vout2 to discharge through the second MOSFET Q3 and the second resistor assembly 141 to ground.
[0090] In one exemplary embodiment, such as Figure 4 As shown, when the power supply output terminal Vout includes a first power supply output terminal Vout1 and a second power supply output terminal Vout2 with different voltage levels, the power-off discharge circuit may further include: a second discharge module 140 and a second control module 150.
[0091] Correspondingly, the first terminal of the second control module 150 is connected to the first power supply output terminal Vout1, the second terminal of the second control module 150 is grounded, the control terminal of the second control module 150 is connected to the controlled terminal of the second discharge module 140, the first terminal of the second discharge module 140 is connected to the second power supply output terminal Vout2, and the second terminal of the second discharge module 140 is grounded. The second discharge module 140 is used to discharge the energy storage device connected to the second power supply output terminal Vout2 when the first power supply output terminal Vout1 has completed discharging.
[0092] This can be understood as the possibility of different power-on sequences when supplying power to loads with different power requirements. For example, the first power supply output terminal Vout1, which converts the output voltage to 5V, is powered first, and then the second power supply output terminal Vout2, which converts the output voltage to 3.3V, is powered second. Furthermore, for application scenarios with different power-on sequences, this application can also add a second control module 150 connected to the first power supply output terminal Vout1. This second control module 140 controls the second discharge module 140 through the first power supply output terminal Vout1, discharging the energy storage device connected to the second power supply output terminal Vout2 when the first power supply output terminal Vout1 has completed discharging.
[0093] In one exemplary embodiment, continuing with reference to Figure 4 The second control module 150 includes an eighth resistor R8 and a ninth resistor R9. The eighth resistor R8 and the ninth resistor R9 are connected in series, with the first terminal serving as the first terminal of the second control module 150, the second terminal serving as the second terminal of the second control module 150, and the common terminal serving as the control terminal of the second control module 150. The second discharge module 140 includes a second MOSFET Q3 and a second resistor assembly 141. The gate of the second MOSFET Q3 is connected to the control terminal of the second control module 150, the source of the second MOSFET Q3 is connected to the second power supply output terminal Vout2, and the drain of the second MOSFET Q3 is grounded through the second resistor assembly 141.
[0094] Specifically, the eighth resistor R8 and the ninth resistor R9 are connected in series. The first end is connected to the first power supply output terminal Vout1, the second end is grounded, and the common end is connected to the gate of the second MOSFET Q3. When the first power supply output terminal Vout1 completes its discharge, the supply voltage of the first power supply output terminal Vout1 drops rapidly to zero, thereby causing the gate of the second MOSFET Q3 to be grounded and turned on through the ninth resistor R9, discharging the energy storage device connected to the second power supply output terminal Vout2.
[0095] In one exemplary embodiment, such as Figure 5As shown in the embodiments of this application, a battery control unit is also provided, including a control chip 10, a power conversion device 20, and a power-off discharge circuit 30 as described in any of the above embodiments. The power conversion device 20 is connected to an external power source through the power input terminal Vin, performs voltage conversion to obtain a power supply voltage, and outputs it to the control chip 10 through the power output terminal Vout. The power-off discharge circuit 30 is used to discharge the energy storage device connected to the power output terminal Vout when the external power supply is in a power-off state.
[0096] Specifically, the power conversion device 20 provided between the power input terminal Vin and the power output terminal Vout is used to convert the external power supply connected to the power input terminal Vin into a power supply voltage that matches the power supply requirements of the control chip 10, and output it to the control chip 10 through the power output terminal Vout.
[0097] It should be noted that the power output terminal Vout is connected to an energy storage device, whose rapid charging and discharging characteristics can be used to optimize the stability and response speed of the power supply system. For example, in a scenario where power is supplied to the control chip 10, the switching action of its internal transistors will generate high-frequency transient currents, causing power supply voltage fluctuations. In this case, the energy storage device absorbs these high-frequency noises through a low-impedance path, preventing noise from coupling to the power supply pins and affecting the normal operation of the power supply side.
[0098] However, in certain application scenarios, when the battery control unit is quickly plugged in and out, and the power supply is suddenly disconnected and then quickly restored, the energy stored in the energy storage device connected to the power output terminal Vout cannot be released quickly due to the short time interval between power failure and restoration, resulting in a certain residual voltage. During the power restoration phase, the residual voltage can easily cause the control chip 10 to fail to start, freeze, crash, or even crash, or in severe cases, cause the program to drop out.
[0099] The power failure discharge circuit 30 can be connected to the power supply input terminal Vin via the input terminal of the power failure detection module to provide feedback on the power supply status of the external power source. Then, the controlled terminal of the first control module is connected to the output terminal of the power failure detection module, triggering the first control module to conduct when the external power supply is in a power failure state. The controlled terminal of the first discharge module is connected to the output terminal of the first control module, the first terminal of the first discharge module is connected to the power supply output terminal Vout, and the second terminal of the first discharge module is grounded, discharging the energy storage device connected to the power supply output terminal Vout when the first control module is turned on.
[0100] In this embodiment, the above design allows for discharge after power failure, quickly releasing the residual voltage of the internal energy storage device. This improves the situation where the power-on timing of the powered control chip is disordered when the time interval between power failure and power-on is short.
[0101] In one exemplary embodiment, this application also provides a battery management system, including the battery control unit as described above.
[0102] The solution provided by the above-mentioned battery control unit and battery management system is similar to the solution described in the above-mentioned power-off discharge circuit. Therefore, the specific limitations of the one or more battery control units and battery management system embodiments provided above can be found in the limitations of the power-off discharge circuit above, and will not be repeated here.
[0103] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0104] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A power-off discharge circuit, characterized in that, The power-off discharge circuit includes: Power input terminal, used to connect to an external power source; The power supply output terminal connected to the energy storage device is used to output the power supply voltage to the load; A power failure detection module, wherein the input terminal of the power failure detection module is connected to the power supply input terminal, and the output terminal of the power failure detection module is used to provide feedback on the power supply status of the external power supply; The first control module is connected to the output of the power failure detection module. The first control module is triggered to conduct when the power supply of the external power source is in a power failure state. The first discharge module has its controlled terminal connected to the output terminal of the first control module, its first terminal connected to the power supply output terminal, and its second terminal grounded. The first discharge module is used to discharge the energy storage device connected to the power supply output terminal when the first control module is turned on.
2. The power-off discharge circuit according to claim 1, characterized in that, The power failure detection module includes a current limiting protection unit and an optocoupler isolation unit. The input terminal of the current limiting protection unit is connected to the power supply input terminal, the output terminal of the current limiting protection unit is connected to the input terminal of the optocoupler isolation unit, and the output terminal of the optocoupler isolation unit is connected to the controlled terminal of the first control module.
3. The power-off discharge circuit according to claim 2, characterized in that, The power input terminal includes a positive power supply terminal and a negative power supply terminal. The current limiting protection unit includes a first resistor, a second resistor, and a first diode. The positive power supply terminal is connected to the cathode of the first diode through the first resistor, and the negative power supply terminal is connected to the anode of the first diode through the second resistor. The cathode and anode of the first diode also serve as the output terminals of the current limiting protection unit.
4. The power-off discharge circuit according to claim 3, characterized in that, The optocoupler isolation unit includes an optocoupler, the anode of which is connected to the cathode of the first diode, the cathode of which is connected to the anode of the first diode, the collector of which is used to provide feedback on the power supply status of the external power source, and the emitter of which is grounded.
5. The power-off discharge circuit according to claim 2, characterized in that, The controlled end of the first control module is also connected to the power supply output end; When the external power supply is in a power-off state, the output terminal of the optocoupler isolation unit is in a cut-off state, and the first control module is triggered to conduct by the power supply voltage of the power supply output terminal; When the external power supply is in a normal power supply state, the controlled terminal of the first control module is grounded through the output terminal of the optocoupler isolation unit, and the first control module remains in a cut-off state.
6. The power-off discharge circuit according to claim 5, characterized in that, The first control module includes a first switch, a third resistor, a fourth resistor, and a fifth resistor. The base of the first switch is connected to the output terminal of the optocoupler isolation unit through the third resistor. The base of the first switch is also connected to the power supply output terminal through the third resistor and the fourth resistor in sequence. The collector of the first switch is connected to the power supply output terminal through the fifth resistor. The collector of the first switch serves as the output terminal of the first control module, and the emitter of the first switch is grounded.
7. The power-off discharge circuit according to claim 1, characterized in that, The power supply output terminal includes a first power supply output terminal and a second power supply output terminal that output different voltage levels; The controlled terminal of the first discharge module is connected to the output terminal of the first control module, the first terminal of the first discharge module is connected to the first power supply output terminal, and the second terminal of the first discharge module is grounded. The first discharge module is used to discharge the energy storage device connected to the first power supply output terminal when the first control module is turned on. The power-off discharge circuit further includes: a second discharge module; The controlled terminal of the second discharge module is connected to the output terminal of the first control module, the first terminal of the second discharge module is connected to the second power supply output terminal, and the second terminal of the second discharge module is grounded. The second discharge module is used to discharge the energy storage device connected to the second power supply output terminal when the first control module is turned on.
8. The power-off discharge circuit according to claim 1, characterized in that, The power supply output terminal includes a first power supply output terminal and a second power supply output terminal that output different voltage levels; The controlled terminal of the first discharge module is connected to the output terminal of the first control module, the first terminal of the first discharge module is connected to the first power supply output terminal, and the second terminal of the first discharge module is grounded. The first discharge module is used to discharge the energy storage device connected to the first power supply output terminal when the first control module is turned on. The power-off discharge circuit further includes: a second control module and a second discharge module; The first end of the second control module is connected to the first power supply output terminal, the second end of the second control module is grounded, the control terminal of the second control module is connected to the controlled terminal of the second discharge module, the first end of the second discharge module is connected to the second power supply output terminal, the second end of the second discharge module is grounded, and the second discharge module is used to discharge the energy storage device connected to the second power supply output terminal when the first power supply output terminal completes the discharge.
9. The power-off discharge circuit according to claim 7 or 8, characterized in that, The first discharge module includes a first MOSFET, a first resistor assembly, and a sixth resistor. The gate of the first MOSFET is connected to the output terminal of the first control module through the sixth resistor. The source of the first MOSFET is connected to the first power supply output terminal. The drain of the first MOSFET is grounded through the first resistor assembly.
10. The power-off discharge circuit according to claim 7, characterized in that, The second discharge module includes a second MOSFET, a second resistor assembly, and a seventh resistor. The gate of the second MOSFET is connected to the output terminal of the first control module through the seventh resistor. The source of the second MOSFET is connected to the second power supply output terminal. The drain of the second MOSFET is grounded through the second resistor assembly.
11. The power-off discharge circuit according to claim 8, characterized in that, The second control module includes an eighth resistor and a ninth resistor. The eighth resistor and the ninth resistor are connected in series, with the first end serving as the first end of the second control module, the second end serving as the second end of the second control module, and the common end serving as the control end of the second control module.
12. The power-off discharge circuit according to claim 11, characterized in that, The second discharge module includes a second MOSFET and a second resistor assembly. The gate of the second MOSFET is connected to the control terminal of the second control module, the source of the second MOSFET is connected to the second power supply output terminal, and the drain of the second MOSFET is grounded through the second resistor assembly.
13. A battery master control unit, characterized in that, Includes a control chip, a power conversion device, and a power-off discharge circuit as described in any one of claims 1 to 12; The power conversion device is connected to an external power source through the power input terminal, performs voltage conversion to obtain the power supply voltage, and outputs it to the control chip through the power output terminal to supply power. The power-off discharge circuit is used to discharge the energy storage device connected to the power supply output terminal when the external power supply is in a power-off state.
14. A battery management system, characterized in that, Includes the battery control unit as described in claim 13.