Overvoltage detection circuit and battery management system
The overvoltage detection circuit composed of a voltage-stabilizing diode, a resistor and a transistor utilizes the voltage division principle and the switching characteristics of the transistor to solve the problem of high overvoltage detection cost in the existing technology and realize low-cost overvoltage detection.
Patent Information
- Application Number
- CN202422426077.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2034-09-30
AI Technical Summary
In the prior art, when an MCU or an operational amplifier is added to the system to perform overvoltage detection, the cost is high.
The overvoltage detection circuit composed of a voltage-stabilizing diode, a resistor and a transistor is adopted, and the voltage division principle and the switching characteristics of the transistor are utilized to realize overvoltage detection of the controller.
A low-cost overvoltage detection solution is provided, which effectively reduces the cost of the overvoltage detection circuit.
Smart Images
Figure CN223320482U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of overvoltage detection, and in particular to an overvoltage detection circuit and a battery management system. Background Art
[0002] In the related art, when performing overvoltage detection on a controller in a system, it is generally achieved by adding a small microcontroller unit (MCU) or operational amplifier to the system. However, the chips of operational amplifiers and MCUs are generally expensive, which increases the cost of overvoltage detection of the controller. Utility Model Content
[0003] The main purpose of this application is to provide an overvoltage detection circuit and a battery management system, aiming to solve the technical problem of high cost of overvoltage detection of the controller in the related art.
[0004] To achieve the above object, the present application proposes an overvoltage detection circuit that can be used to detect the input voltage of a controller. The overvoltage detection circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, a resistor R3, and a transistor Q1;
[0005] The anode of the Zener diode D1 is connected to one end of the resistor R2, the other end of the resistor R2 is respectively connected to one end of the resistor R3 and the base of the transistor Q1, the collector of the transistor Q1 is respectively connected to one end of the resistor R1 and the signal receiving end of the controller, the other end of the resistor R1 is respectively connected to the cathode of the Zener diode D1 and the voltage input end of the controller, and the other end of the resistor R3 and the emitter of the transistor Q1 are both grounded.
[0006] In one embodiment, the transistor Q1 is an NPN transistor.
[0007] In one embodiment, the voltage stabilizing diode D1 is configured to reversely break down when the input voltage of the controller exceeds a voltage threshold, so as to turn on the transistor Q1 .
[0008] In one embodiment, the voltage threshold is determined by adjusting the resistance values of the resistor R1 , the resistor R2 , and the resistor R3 .
[0009] In one embodiment, the voltage threshold value ranges from 3.3V to 4V.
[0010] In one embodiment, the resistance value of the resistor R1 is 10 kΩ, the resistance value of the resistor R2 is 10 kΩ, and the resistance value of the resistor R3 is 3.9 kΩ.
[0011] In one embodiment, the overvoltage detection circuit is further configured to output an overvoltage detection signal to a signal receiving terminal of the controller;
[0012] The controller is used to generate and output overvoltage alarm information according to the overvoltage detection signal.
[0013] In addition, to achieve the above objectives, the present application also proposes a battery management system, which includes:
[0014] Power conversion module;
[0015] The control module includes the overvoltage detection circuit and the controller as described above. The overvoltage detection circuit is connected to the controller and the power conversion module respectively.
[0016] In one embodiment, the power conversion module includes a DC-DC converter, which is connected to the voltage input terminal of the controller and the overvoltage detection circuit respectively, and is used to step down the received power supply voltage to provide an input voltage for the controller; or,
[0017] It includes an LDO low-voltage linear regulator, which is connected to the voltage input terminal of the controller and the overvoltage detection circuit respectively, and is used to step down and stabilize the received power supply voltage to provide input voltage for the controller.
[0018] In one embodiment, the power conversion module may include a DC-DC converter and an LDO low-voltage linear regulator, and the DC-DC converter is connected to the voltage input terminal of the controller and the overvoltage detection circuit respectively through the LDO low-voltage linear regulator;
[0019] The DC-DC converter is used to step down the received power supply voltage, and the LDO low-voltage linear regulator is used to stabilize the stepped-down power supply voltage to provide input voltage for the controller.
[0020] One or more technical solutions proposed in this application have at least the following technical effects:
[0021] The overvoltage detection circuit provided in the present application provides a low-cost overvoltage detection solution through a combination of simple components such as a voltage-stabilizing diode D1, a resistor R1, a resistor R2, a resistor R3 and a transistor Q1, thereby realizing overvoltage detection of the controller. Compared with the use of expensive MCUs or operational amplifiers, the overvoltage detection circuit of the present application utilizes the voltage division principle and the switching characteristics of transistors to achieve effective overvoltage detection, and the selection of voltage-stabilizing diodes, resistors and transistors with low material and production costs can effectively reduce the cost of the overvoltage detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0024] Figure 1 This is a circuit structure diagram of Example 1 of the overvoltage detection circuit of the present application;
[0025] Figure 2 This is a connection diagram of the first embodiment of the battery management system of this application;
[0026] Figure 3 The figure is a schematic diagram of the circuit structure of an overvoltage detection circuit in a battery management system.
[0027] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0028] It should be understood that the specific embodiments described herein are merely used to explain the technical solutions of the present application and are not intended to limit the present application.
[0029] In order to better understand the technical solution of this application, the following will be described in detail with reference to the accompanying drawings and specific implementation methods. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.
[0030] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.
[0031] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.
[0032] In related technologies, when performing overvoltage detection on the controller of a system such as a battery management system, it is generally achieved by adding a small MCU or operational amplifier to the system. However, the chips of the operational amplifier and MCU are relatively expensive, which increases the overvoltage detection cost of the controller.
[0033] In order to solve this technical problem, an overvoltage detection circuit of the present application is proposed, which can be used to detect the input voltage of the controller. The overvoltage detection circuit includes a Zener diode D1, a resistor R1, a resistor R2, a resistor R3 and a transistor Q1; wherein, the anode of the Zener diode D1 is connected to one end of the resistor R2, the other end of the resistor R2 is respectively connected to one end of the resistor R3 and the base of the transistor Q1, the collector of the transistor Q1 is respectively connected to one end of the resistor R1 and the signal receiving end of the controller, the other end of the resistor R1 is respectively connected to the cathode of the Zener diode D1 and the voltage input end of the controller, and the other end of the resistor R3 and the emitter of the transistor Q1 are both grounded.
[0034] The above-mentioned overvoltage detection circuit provides a low-cost overvoltage detection solution through a combination of simple components such as a voltage-stabilizing diode D1, a resistor R1, a resistor R2, a resistor R3 and a transistor Q1, thereby realizing overvoltage detection of the controller. Compared with the use of expensive MCUs or operational amplifiers, the overvoltage detection circuit of the present application utilizes the voltage division principle and the switching characteristics of the transistor to achieve effective overvoltage detection, and the selection of voltage-stabilizing diodes, resistors and transistors with low material and production costs can effectively reduce the cost of the overvoltage detection circuit.
[0035] The following will describe and introduce the present invention through multiple embodiments.
[0036] See also Figure 1 , Figure 1 This is a circuit structure diagram of Example 1 of the overvoltage detection circuit of this application.
[0037] In this embodiment, the overvoltage detection circuit can be used to detect the input voltage of the controller, such as Figure 1 As shown, the overvoltage detection circuit includes a voltage stabilizing diode D1, a resistor R1, a resistor R2, a resistor R3 and a transistor Q1.
[0038] Among them, the anode of the Zener diode D1 is connected to one end of the resistor R2, the other end of the resistor R2 is respectively connected to one end of the resistor R3 and the base of the transistor Q1, the collector of the transistor Q1 is respectively connected to one end of the resistor R1 and the signal receiving end of the controller, the other end of the resistor R1 is respectively connected to the cathode of the Zener diode D1 and the voltage input end of the controller, and the other end of the resistor R3 and the emitter of the transistor Q1 are both grounded.
[0039] Specifically, the controller can be an MCU, or a control chip such as a Field Programmable Gate Array (FPGA) or a Digital Signal Processing (DSP), without limitation. The overvoltage detection circuit can detect the input voltage of the controller and output an overvoltage detection signal to a signal receiving terminal of the controller. The controller can generate and output an overvoltage alarm based on the overvoltage detection signal to alert the user that the controller currently has an overvoltage problem.
[0040] Under normal power supply conditions, transistor Q1 is in a non-conducting state. At this time, the overvoltage detection signal received by the controller's signal receiving end is the input voltage, meaning the overvoltage detection signal received by the controller is a high-level signal. At this time, the controller does not have an overvoltage problem. The cathode of Zener diode D1 is connected to the controller's voltage input. When the controller's input voltage exceeds the voltage threshold, Zener diode D1 undergoes reverse breakdown. At this time, the base voltage of transistor Q1 rises above its turn-on threshold, turning on transistor Q1. A path can be formed between its collector and emitter. At this time, the controller's signal receiving end is grounded through the path between the collector and emitter of transistor Q1. After transistor Q1 turns on, the controller's signal receiving end receives a grounded low-level signal. That is, when the controller is overvoltage, the overvoltage detection signal received by the controller is a low-level signal. The transistor Q1 can be an NPN transistor or a switching device capable of achieving similar functions.
[0041] The above-mentioned voltage threshold can be determined by adjusting the resistance values of resistors R1, R2, and R3. It can be understood that resistors R2 and R3 form a voltage divider. The input voltage can be distributed to the base of transistor Q1 through these resistors, thereby determining the operating state of Q1. When the base voltage exceeds a certain threshold, transistor Q1 will turn on. Increasing resistor R1 will reduce the voltage at the base of Q1, and a higher input voltage may be required to turn on transistor Q1. Increasing resistor R2 or reducing resistor R3 will increase the base voltage, making it easier for transistor Q1 to turn on. Therefore, by adjusting the resistance values of resistors R1, R2, and R3, the voltage division ratio can be changed, thereby accurately setting the voltage threshold of the overvoltage detection circuit. The voltage threshold value can range from 3.3V to 4V. In one feasible embodiment, the resistance value of resistor R1 is 10kΩ, the resistance value of resistor R2 is 10kΩ, and the resistance value of resistor R3 is 3.9kΩ.
[0042] The controller can determine whether it is overvoltage based on the level of the received overvoltage detection signal, and control the execution of related overvoltage response operations; for example, the controller can be connected to an external alarm circuit or an overvoltage protection circuit. When the controller receives a low-level overvoltage detection signal, it can control the external alarm circuit to alarm (such as lighting up the indicator light, sounding the buzzer, etc.), or it can control the overvoltage protection circuit to work and perform overvoltage protection on the controller.
[0043] It is not difficult to understand that the overvoltage detection circuit provided in this embodiment provides a low-cost overvoltage detection solution through a combination of simple components such as a voltage-stabilizing diode D1, a resistor R1, a resistor R2, a resistor R3 and a transistor Q1, thereby realizing overvoltage detection of the controller. Compared with the use of expensive MCUs or operational amplifiers, the overvoltage detection circuit of the present application utilizes the voltage division principle and the switching characteristics of the transistor to achieve effective overvoltage detection, and the selection of voltage-stabilizing diodes, resistors and transistors with low material and production costs can effectively reduce the cost of the overvoltage detection circuit.
[0044] Furthermore, the present application also proposes a battery management system, which may include a power conversion module and a control module; the control module includes the overvoltage detection circuit and controller as described above. Figure 2 As shown, Figure 2 This is a connection diagram of the battery management system. The specific structure of the overvoltage detection circuit can refer to the above embodiments. Since the battery management system of the present application adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.
[0045] Wherein, the overvoltage detection circuit is connected to the controller and the power conversion module respectively. The power conversion module can convert the supply voltage into an input voltage that meets the power supply requirements of the controller. In a feasible embodiment, the power conversion module may include a DC-DC converter, which is connected to the voltage input terminal of the controller and the overvoltage detection circuit respectively, and can be used to step down the received supply voltage to provide an input voltage for the controller; the DC-DC converter can be a buck (Buck) circuit, which is used to reduce the DC supply voltage to a lower output voltage to provide an output voltage for the controller. For example, in a battery management system, the controller is an MCU, and the upper limit of the operating voltage of the MCU is generally 3.6V. For the safe operation of the system, 3.3V is generally designed as the input voltage of the MCU, but the supply voltage is generally 5V DC voltage, so a DC-DC converter can be used to step down the 5V voltage to obtain a 3.3V controller input voltage.
[0046] Alternatively, the power conversion module may include a low-voltage linear regulator (LDO). The LDO is connected to the voltage input terminal of the controller and the overvoltage detection circuit, and can step down and stabilize the received supply voltage to provide the input voltage for the controller. The LDO can also stabilize the voltage while stepping down the voltage to obtain a smoother input voltage.
[0047] In another feasible embodiment, the power conversion module includes a DC-DC converter and an LDO low-voltage linear regulator. The DC-DC converter can be connected to the voltage input terminal and the overvoltage detection circuit of the controller respectively through the LDO low-voltage linear regulator; the DC-DC converter is used to step down the received power supply voltage, and the LDO low-voltage linear regulator is used to stabilize the power supply voltage after the step-down process to provide the controller with the input voltage. The DC-DC converter can directly step down the voltage, and its step-down efficiency is high, but the voltage ripple after processing is usually large and the stability is insufficient; while the LDO can stabilize the voltage while stepping down the voltage, its processing efficiency is low. Therefore, in order to achieve a better voltage conversion effect, a DC-DC converter can be used to reduce the voltage first to improve the processing efficiency, and then an LDO can be used to further smooth the output, reduce the ripple, and achieve a balance between high efficiency and low noise.
[0048] In the battery management system described above, if the DC-DC converter or LDO breaks down, the 5V supply voltage will directly power the MCU. However, most MCUs currently have a 5V withstand voltage. This means that even if the relevant circuits in the front-end voltage conversion module break down, the MCU will continue to operate, potentially causing greater losses. Therefore, an overvoltage detection circuit can be set in the control module of the battery management system, and the overvoltage detection circuit is connected to the controller and the power conversion module respectively. Figure 3 As shown, Figure 3 This is a schematic diagram of the overvoltage detection circuit in a battery management system. In this example, the voltage regulation value of Zener diode D1 is designed to be 3.3V. A BZT52C3V3S SOD323 Zener diode can be used to detect the 3.3V_MCU input voltage and control the conduction of transistor Q1. Transistor Q1 is an LMBT5551LT1G NPN transistor. Resistor R1 is 10kΩ, R2 is 10kΩ, and R3 is 3.9kΩ. Resistors R1 through R3 can all be R0603 resistors. When the DC-DC converter or LDO in the power conversion module breaks down, the voltage of 3.3V_MCU rises to 5V. At this time, the voltage regulator diode D1 is reversely broken down, and the transistor Q1 reaches the turn-on condition. The overvoltage detection signal of 3.3V_OVD changes from high level to low level, and the controller can issue an overvoltage alarm based on this.
[0049] It can be understood that the battery management system provided in this embodiment includes a power conversion module and a control module; wherein, the control module includes an overvoltage detection circuit constructed using simple devices such as a voltage regulator diode D1, a resistor R1, a resistor R2, a resistor R3 and a transistor Q1, which can realize overvoltage detection of the controller of the battery management system while reducing the construction cost of the battery management system.
[0050] The above description is only part of the embodiments of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.
Claims
1. An overvoltage detection circuit, characterized in that: Used to detect the input voltage of the controller, the overvoltage detection circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, a resistor R3 and a transistor Q1; The anode of the voltage-stabilizing diode D1 is connected to one end of the resistor R2, the other end of the resistor R2 is respectively connected to one end of the resistor R3 and the base of the transistor Q1, the collector of the transistor Q1 is respectively connected to one end of the resistor R1 and the signal receiving end of the controller, the other end of the resistor R1 is respectively connected to the cathode of the voltage-stabilizing diode D1 and the voltage input end of the controller, and the other end of the resistor R3 and the emitter of the transistor Q1 are both grounded.
2. The overvoltage detection circuit according to claim 1, wherein: The transistor Q1 is an NPN transistor.
3. The overvoltage detection circuit according to claim 1, wherein: The voltage stabilizing diode D1 is configured to reversely break down when the input voltage of the controller exceeds a voltage threshold, so as to turn on the transistor Q1.
4. The overvoltage detection circuit according to claim 3, wherein: The voltage threshold is determined by adjusting the resistance values of the resistor R1 , the resistor R2 , and the resistor R3 .
5. The overvoltage detection circuit according to claim 4, wherein: The voltage threshold value ranges from 3.3V to 4V.
6. The overvoltage detection circuit according to claim 5, wherein: The resistance value of the resistor R1 is 10 kΩ, the resistance value of the resistor R2 is 10 kΩ, and the resistance value of the resistor R3 is 3.9 kΩ.
7. The overvoltage detection circuit according to claim 1, wherein: The overvoltage detection circuit is further configured to output an overvoltage detection signal to a signal receiving terminal of the controller; The controller is used to generate and output overvoltage alarm information according to the overvoltage detection signal.
8. A battery management system, characterized in that: The battery management system includes: Power conversion module; A control module comprises the overvoltage detection circuit and the controller according to any one of claims 1 to 7, wherein the overvoltage detection circuit is connected to the controller and the power conversion module respectively.
9. The battery management system according to claim 8, characterized in that: The power conversion module includes a DC-DC converter, which is connected to the voltage input terminal of the controller and the overvoltage detection circuit respectively, and is used to step down the received power supply voltage to provide the input voltage to the controller; or, It includes an LDO low-voltage linear regulator, which is connected to the voltage input terminal of the controller and the overvoltage detection circuit respectively, and is used to step down and stabilize the received power supply voltage to provide the input voltage for the controller.
10. The battery management system according to claim 8, wherein: The power conversion module includes a DC-DC converter and an LDO low-voltage linear regulator, and the DC-DC converter is connected to the voltage input terminal of the controller and the overvoltage detection circuit respectively through the LDO low-voltage linear regulator; The DC-DC converter is used to step down the received power supply voltage, and the LDO low-voltage linear regulator is used to stabilize the stepped-down power supply voltage to provide the input voltage for the controller.