Overvoltage protection circuit, power supply system and energy storage equipment

Abstract

The utility model discloses an overvoltage protection circuit, a power supply system and energy storage equipment. The overvoltage protection circuit comprises a switch module, a controllable voltage stabilization source and a voltage division module. The switch module is switched on in response to the first voltage when the controllable voltage stabilization source is not switched on so as to output the second voltage to the first node. The voltage dividing module divides the voltage of the first node, divides the second voltage when the switch module is switched on, and outputs a third voltage to the second node. The controllable voltage stabilization source is turned on in response to the third voltage being greater than the first voltage threshold value, and stabilizes the voltage of the second node at the first voltage threshold value. The switch module is switched off when the controllable voltage stabilization source is switched on. The voltage dividing module clamps the voltage of the first node to a fourth voltage based on a first voltage threshold when the controllable voltage stabilizing source is switched on. By means of the mode, overvoltage protection can be rapidly achieved, and the risk that devices are damaged is reduced.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to an overvoltage protection circuit, a power supply system, and an energy storage device. Background Technology

[0002] With the rapid development of the new energy industry, the use of energy storage devices has become increasingly widespread, and the functional safety considerations for these devices have become more stringent. Energy storage devices typically include modules for voltage conversion, and for these modules, it is usually necessary to determine whether overvoltage has occurred in the output voltage and take appropriate measures when overvoltage occurs.

[0003] Currently, the common implementation method involves a controller determining the output voltage of the voltage conversion module and stopping the module when the voltage exceeds this limit, thus providing overvoltage protection. However, this method places extremely high demands on the controller's operating speed, which may lead to untimely overvoltage protection and potentially damage to the device. Utility Model Content

[0004] This application provides an overvoltage protection circuit, a power supply system, and an energy storage device, which can quickly achieve overvoltage protection and reduce the risk of device damage.

[0005] In a first aspect, embodiments of this application provide an overvoltage protection circuit, including:

[0006] Switching modules, controllable voltage regulators, and voltage divider modules;

[0007] The first terminal of the switching module is connected to the first terminal of the non-reference terminal of the controllable voltage regulator. The reference terminal of the controllable voltage regulator is connected to the second terminal of the voltage divider module at the second node. The first terminal of the voltage divider module is connected to the second terminal of the switching module at the first node. The second terminal of the non-reference terminal of the controllable voltage regulator and the third terminal of the voltage divider module are both grounded.

[0008] The fourth terminal of the switching module receives a first voltage, and the third terminal of the switching module receives a second voltage. The switching module is used to turn on in response to the first voltage when the controllable voltage source is not turned on, so as to output the second voltage to the first node.

[0009] The voltage divider module is used to divide the voltage of the first node, wherein when the switch module is turned on, the voltage divider module divides the second voltage and outputs a third voltage to the second node;

[0010] The controllable voltage regulator is used to turn on in response to the third voltage being greater than the first voltage threshold, and to stabilize the voltage of the second node at the first voltage threshold.

[0011] The switching module is also used to disconnect when the controllable voltage source is turned on;

[0012] The voltage divider module is also used to clamp the voltage of the first node to a fourth voltage based on the first voltage threshold when the controllable voltage source is turned on.

[0013] In one or more embodiments, the overvoltage protection circuit further includes a differentiating module;

[0014] The differential module is connected between the first node and the second node, and the differential module is used to adjust the response speed of clamping the voltage of the first node.

[0015] In one or more embodiments, the switching module includes a switching transistor and a first resistor;

[0016] The first terminal of the switching transistor is connected to the first terminal of the non-reference terminal of the controllable voltage regulator and the first terminal of the first resistor, respectively. The second terminal of the first resistor is input with the first voltage. The second terminal of the switching transistor is connected to the first node. The third terminal of the switching transistor is input with the second voltage.

[0017] In one or more embodiments, the voltage divider module includes a second resistor and a third resistor;

[0018] The second resistor and the third resistor are connected in series between the first node and ground, and the connection point between the second resistor and the third resistor is the second node.

[0019] In one or more embodiments, the differentiating module includes a fourth resistor and a first capacitor;

[0020] The fourth resistor is connected in series with the first capacitor between the first node and the second node.

[0021] Secondly, embodiments of this application provide a power supply system, including:

[0022] The first voltage conversion module receives a first input voltage and converts the first input voltage into a first output voltage.

[0023] The first overvoltage protection circuit, as described above, is connected to the first voltage conversion module. The first voltage input to the first overvoltage protection circuit is the first input voltage, and the second voltage input to the first overvoltage protection circuit is the first output voltage.

[0024] In one or more embodiments, the power supply system further includes:

[0025] The second voltage conversion module takes the first output voltage as input and converts the first output voltage into the second output voltage.

[0026] The second overvoltage protection circuit, as described above, is connected to the second voltage conversion module. The first voltage input to the second overvoltage protection circuit is the first input voltage, and the second voltage input to the first overvoltage protection circuit is the second output voltage.

[0027] In one or more embodiments, the power supply system further includes:

[0028] The third voltage conversion module receives a second input voltage and converts the second input voltage into the first input voltage during its operation.

[0029] The voltage detection module takes the first output voltage and the second output voltage as input, and outputs a first detection voltage based on the first output voltage and a second detection voltage based on the second output voltage.

[0030] The controller, connected to the voltage detection module, is used to output a control signal to the third voltage conversion module when the first detected voltage is greater than the second voltage threshold and / or the second detected voltage is greater than the third voltage threshold, so as to stop the third voltage conversion module from working.

[0031] In one or more embodiments, the voltage detection module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second capacitor, a third capacitor, a first Zener diode, and a second Zener diode;

[0032] The first terminal of the fifth resistor is input to the second output voltage. The second terminal of the fifth resistor is connected to the first terminal of the sixth resistor and the first terminal of the seventh resistor. The second terminal of the seventh resistor is connected to the anode of the first Zener diode and the first terminal of the second capacitor. The cathode of the first Zener diode is input to the first output voltage. The second terminal of the sixth resistor and the second terminal of the second capacitor are both grounded.

[0033] The first terminal of the eighth resistor receives the first output voltage, the second terminal of the eighth resistor is connected to the first terminal of the ninth resistor and the first terminal of the tenth resistor, the second terminal of the tenth resistor is connected to the anode of the second Zener diode and the first terminal of the third capacitor, the cathode of the second Zener diode receives the first output voltage, and the second terminal of the ninth resistor and the second terminal of the third capacitor are both grounded.

[0034] Thirdly, embodiments of this application provide an energy storage device, including the overvoltage protection circuit described above or the power supply system described above.

[0035] The beneficial effects of this application are as follows: The overvoltage protection circuit of this application embodiment includes a switching module, a controllable voltage regulator, and a voltage divider module. The first terminal of the switching module is connected to the first terminal of the non-reference terminal of the controllable voltage regulator. The reference terminal of the controllable voltage regulator is connected to the second terminal of the voltage divider module at a second node. The first terminal of the voltage divider module is connected to the second terminal of the switching module at a first node. The second terminal of the non-reference terminal of the controllable voltage regulator and the third terminal of the voltage divider module are both grounded. A first voltage is input to the fourth terminal of the switching module, and a second voltage is input to the third terminal of the switching module. When the circuit is operating normally, i.e., when no overvoltage occurs, the controllable voltage regulator is not turned on, and the switching module turns on in response to the first voltage to output the second voltage to the first node; the voltage divider module divides the second voltage and outputs a third voltage to the second node. Subsequently, if an overvoltage occurs, the third voltage will exceed the first voltage threshold, causing the controllable voltage regulator to turn on and stabilize the voltage at the second node at the first voltage threshold. On one hand, the switching module will turn off; on the other hand, with the voltage at the second node stabilized at the first voltage threshold, the voltage divider module will clamp the voltage at the first node to the fourth voltage based on the first voltage threshold. Furthermore, by setting the fourth voltage to a smaller value, the risk of damage to devices due to excessive voltage at the first node during an overvoltage event can be reduced. All of the above processes are implemented through hardware circuitry, resulting in a faster response time compared to related technologies that use controller output signals, thus achieving rapid overvoltage protection. Attached Figure Description

[0036] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0037] Figure 1 This is a schematic diagram of the overvoltage protection circuit provided in the embodiments of this application. Figure 1 ;

[0038] Figure 2 This is a schematic diagram of the overvoltage protection circuit provided in the embodiments of this application. Figure 2 ;

[0039] Figure 3 Is with Figure 2 A schematic diagram of the circuit structure corresponding to the block diagram shown;

[0040] Figure 4 This is a schematic diagram of the power supply system provided in the embodiments of this application. Figure 1 ;

[0041] Figure 5 This is a schematic diagram of the power supply system provided in the embodiments of this application. Figure 2 ;

[0042] Figure 6 This is a schematic diagram of the power supply system provided in the embodiments of this application. Figure 3 ;

[0043] Figure 7 Is with Figure 6 A schematic diagram of the circuit structure corresponding to the block diagram shown;

[0044] Figure 8 yes Figure 7 The circuit shown has the overvoltage protection circuit 100 removed. Figure 7 The diagram shows the signals in the circuit. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0046] It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements between them.

[0047] Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0048] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the block diagram of the overvoltage protection circuit provided in the embodiments of this application. Figure 1 As shown, the overvoltage protection circuit 100 includes a switching module 10, a controllable voltage regulator U1, and a voltage divider module 20.

[0049] In this configuration, the first terminal of the switch module 10 is connected to the first terminal of the non-reference terminal of the controllable voltage source U1, the reference terminal of the controllable voltage source U1 is connected to the second terminal of the voltage divider module 20 at the second node N2, the first terminal of the voltage divider module 20 is connected to the second terminal of the switch module 10 at the first node N1, and the second terminal of the non-reference terminal of the controllable voltage source U1 and the third terminal of the voltage divider module 20 are both grounded to GND.

[0050] Specifically, the fourth terminal of the switching module 10 receives a first voltage V1, and the third terminal receives a second voltage V2. The switching module 10 is configured to turn on in response to the first voltage V1 when the controllable voltage source U1 is not turned on, so as to output the second voltage V2 to the first node N1. The voltage divider module 20 is used to divide the voltage of the first node N1, wherein, when the switching module 10 is turned on, the voltage divider module 20 divides the second voltage V2 and outputs a third voltage to the second node N2. The controllable voltage source U1 is configured to turn on in response to the third voltage being greater than a first voltage threshold, and stabilize the voltage of the second node N2 at the first voltage threshold. The switching module 10 is also configured to turn off when the controllable voltage source U1 is turned on. The voltage divider module 20 is also configured to clamp the voltage of the first node N1 to a fourth voltage based on the first voltage threshold when the controllable voltage source U1 is turned on.

[0051] The first voltage threshold is a preset voltage threshold, which can be set based on the actual application scenario, as long as the corresponding third voltage is greater than the first voltage threshold during overvoltage. In some embodiments, the controllable voltage regulator U1 is configured as a controllable precision voltage regulator of model TL431, and the first voltage threshold can be set to 2.5V. When the third voltage is greater than 2.5V, the controllable voltage regulator U1 is driven to conduct, and at the same time, the voltage at the reference terminal of the controllable voltage regulator U1 is stabilized at 2.5V, that is, the voltage at the second node N2 is stabilized at 2.5V.

[0052] In practical applications, when the overvoltage protection circuit 100 is operating normally, i.e., when no overvoltage occurs, the controllable voltage regulator U1 is not turned on (i.e., the first terminal of the non-reference terminal of the controllable voltage regulator U1 is disconnected from the second terminal of the non-reference terminal of the controllable voltage regulator U1). At this time, the switching module 10 turns on in response to the first voltage V1 to output the second voltage V2 to the first node N2. Then, the voltage divider module 20 divides the second voltage V2 and outputs the third voltage V3 to the second node N2. Since the third voltage V3 is less than the first voltage threshold, the controllable voltage regulator U1 remains in the off state.

[0053] Subsequently, if an overvoltage occurs, the third voltage V3 will exceed the first voltage threshold, and the controllable voltage regulator U1 will turn on. On one hand, the switching module 10 is disconnected, and it no longer outputs the second voltage V2 to the first node N2, thus providing overvoltage protection. On the other hand, the voltage at the reference terminal of the controllable voltage regulator U1 stabilizes at the first voltage threshold, and the voltage at the second node N2 stabilizes at the first voltage threshold. The voltage divider module 20 clamps the voltage at the first node N1 to the fourth voltage based on the first voltage threshold. Then, by setting the fourth voltage to a smaller value, for example, in some embodiments, the voltage division ratio of the voltage divider module 20 can be adjusted so that the fourth voltage is less than or equal to the second voltage V2. This ensures that the voltage at the first node N1 remains less than or equal to the second voltage V2, thereby reducing the risk of device damage due to excessive voltage at the first node N1 during an overvoltage event, thus again providing overvoltage protection. Furthermore, all of the above processes are implemented through hardware circuitry, which offers a faster response speed compared to the controller-output control signal method used in related technologies, thereby achieving rapid overvoltage protection.

[0054] In some embodiments, such as Figure 2 As shown, the overvoltage protection circuit 100 also includes a differentiating module 30.

[0055] The differential module 30 is connected between the first node N1 and the second node N2. The differential module 30 is used to adjust the response speed of clamping the voltage of the first node N1, that is, to adjust the response speed of the voltage of the first node N1 changing from the second voltage V1 to the fourth voltage.

[0056] Please refer to Figure 3 , Figure 3 An example is shown with Figure 2 The block diagram shown corresponds to one type of circuit structure. For example... Figure 3 As shown, the switching module 10 includes a switching transistor Q1 and a first resistor R1.

[0057] The first terminal of the switch Q1 is connected to the first terminal of the non-reference terminal of the controllable voltage regulator U1 and the first terminal of the first resistor R1. The second terminal of the first resistor R1 is input with the first voltage V1. The second terminal of the switch Q1 is connected to the first node N1. The third terminal of the switch Q1 is input with the second voltage V2.

[0058] Specifically, the first resistor R1 is used for current limiting. When the controllable voltage source U1 is not turned on, the first voltage V1 is applied to the gate of the switch Q1, so that the gate-source voltage (i.e., the voltage between the gate and the source) of the switch Q1 is greater than its threshold voltage VTH, and the switch Q1 is turned on. Then, the second voltage V2 is applied to the first node N1 through the switch Q1. At this time, by configuring the difference between the first voltage V1 and the second voltage V2 to still be greater than the threshold voltage VTH, the switch Q1 can be kept on. For example, in some embodiments, the threshold voltage VTH is 2V, the first voltage V1 is 12V, and the second voltage V2 is 5V, then the difference between the first voltage V1 and the second voltage V2 is 7V > VTH.

[0059] When the controllable voltage regulator U1 is turned on, the gate-source voltage of the switch Q1 is less than the threshold voltage VTH, and the switch Q1 is turned off. For example, in some embodiments, the threshold voltage VTH is 2V, the first voltage V1 is 12V, the second voltage V2 is 5.375V, the controllable voltage regulator U1 is a TL431, and the resistance of the first resistor R1 is 2Ω; then, when the controllable voltage regulator U1 is turned on, the first terminal of the non-reference terminal of the controllable voltage regulator U1 is connected to the second terminal of the non-reference terminal of the controllable voltage regulator U1, and the current IR between the first terminal and the second terminal of the non-reference terminal of the controllable voltage regulator U1 is 2.5mA. At this time, the gate voltage of the switch Q1 is V1-R1*2.5*0.001=7V, and the gate-source voltage of the switch Q1 is 7V-5.375=1.65V<2V, so the switch Q1 is turned off.

[0060] In this embodiment, the switch Q1 is an NMOS transistor. The gate of the NMOS transistor is the first terminal of the switch Q1, the source of the NMOS transistor is the second terminal of the switch Q1, and the drain of the NMOS transistor is the third terminal of the switch Q1.

[0061] In addition, the switching transistor Q1 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field-effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0062] In this embodiment, the voltage divider module 20 includes a second resistor R2 and a third resistor R3.

[0063] The second resistor R2 and the third resistor R3 are connected in series between the first node N1 and ground GND, and the connection point between the second resistor R2 and the third resistor R3 is the second node N2.

[0064] Specifically, when the controllable voltage regulator U1 is not turned on, the second resistor R2 and the third resistor R3 are used to divide the voltage of the first node N1, and the voltage of the first node N1 across the third resistor R3 is used as the voltage of the second node N2. When the controllable voltage regulator U1 is turned on, the voltage at the reference terminal of the controllable voltage regulator U1 is stable at the first voltage threshold, and the voltage of the second node N2 is also stable at the first voltage threshold. The voltage of the second node N2 is also the voltage of the third resistor R3. The current flowing through the second resistor R2 and the third resistor R3 is determined based on the ratio of the voltage of the second node N2 to the third resistor R3, and the product of the sum of the voltages of the second resistor R2 and the third resistor R3 and the current flowing through the second resistor R2 and the third resistor R3 is used as the fourth voltage. The voltage of the first node N1 is clamped as the fourth voltage. For example, when the controllable voltage regulator U1 is selected as TL431, if the controllable voltage regulator U1 is turned on, the voltage of the second node N2 is 2.5V, and the fourth voltage is 2.5 / R3*(R2+R3).

[0065] In this embodiment, the differentiating module 30 includes a fourth resistor R4 and a first capacitor C1. The fourth resistor R4 and the first capacitor C1 are connected in series between the first node N1 and the second node N2. By adjusting the resistance value of the fourth resistor R4 and / or the capacitance value of the first capacitor C1, the response speed for clamping the voltage of the first node N1 can be adjusted.

[0066] In summary, Figure 3 In the illustrated embodiment, when an overvoltage occurs, the switch Q1 can be turned off, and the voltage at the first node N1 can be clamped to the fourth voltage, thus achieving overvoltage protection. Secondly, the entire system is implemented using hardware circuitry, which offers a faster response time compared to related technologies that use controller output signals, thereby achieving rapid overvoltage protection. Furthermore, it uses fewer components, resulting in lower cost.

[0067] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the power supply system provided in an embodiment of this application. Figure 4 As shown, the power supply system 1000 includes a first voltage conversion module 200 and a first overvoltage protection circuit 100 in any embodiment of this application.

[0068] In this embodiment, the first voltage conversion module 200 receives a first input voltage VI1 and converts it into a first output voltage VO1. A first overvoltage protection circuit 100 is connected to the first voltage conversion module 200. The first voltage V1 input to the first overvoltage protection circuit 100 is the first input voltage VI1, and the second voltage V2 input to the first overvoltage protection circuit 100 is the first output voltage VO2. That is, in the above embodiment, the first overvoltage protection circuit 100 receives both the first voltage V1 and the second voltage V2. In this embodiment, the first voltage V1 corresponds to the first input voltage VI1, and the second voltage V2 corresponds to the first output voltage VO1.

[0069] Subsequently, in this embodiment, when no overvoltage occurs, the voltage output by the first overvoltage protection circuit 100 is equal to the first output voltage VO1.

[0070] When an overvoltage occurs, such as when the first voltage conversion module 200 malfunctions and causes a short circuit between its output and input terminals, the first output voltage VO1 is equal to the first input voltage VI1. Due to the existence of the first overvoltage protection circuit 100, the voltage output by the first overvoltage protection circuit 100 can be clamped to the fourth voltage, so that subsequent devices will not be damaged due to the increase of the first output voltage VO1.

[0071] In some embodiments, such as Figure 5 As shown, the power supply system 1000 also includes a second voltage conversion module 300 and a second overvoltage protection circuit 100 in any embodiment of this application.

[0072] The second voltage conversion module 300 receives a first output voltage VO1 and converts it into a second output voltage VO2. A second overvoltage protection circuit 100 is connected to the second voltage conversion module 300. The first voltage V1 input to the second overvoltage protection circuit 100 is the first input voltage VI 1, and the second voltage V2 input to the first overvoltage protection circuit 100 is the second output voltage VO2. In this embodiment, the second overvoltage protection circuit 100 receives both the first voltage V1 and the second voltage V2. Specifically, in this embodiment, the first voltage V1 corresponds to the first input voltage VI 1, and the second voltage V2 corresponds to the second output voltage VO2.

[0073] Subsequently, in this embodiment, when no overvoltage occurs, the voltage output by the first overvoltage protection circuit 100 is equal to the second output voltage VO2.

[0074] When an overvoltage occurs, such as when the second voltage conversion module 300 malfunctions and causes a short circuit between its output and input terminals, the second output voltage VO2 is equal to the voltage output by the first overvoltage protection circuit 100. Due to the existence of the second overvoltage protection circuit 100, the voltage output by the second overvoltage protection circuit 100 can be clamped to the fourth voltage, so that subsequent devices will not be damaged due to the increase of the second output voltage VO2.

[0075] It should be noted that the fourth voltage used by the first overvoltage protection circuit 100 for clamping can be the same as or different from the fourth voltage used by the second overvoltage protection circuit 100, as long as the fourth voltage does not cause damage to the second voltage conversion module 300 and subsequent components of the overvoltage protection circuit 100.

[0076] Furthermore, in this embodiment, taking two voltage conversion modules (including a first voltage conversion module 200 and a second voltage conversion module 300) as an example, two overvoltage protection circuits 100 can be correspondingly set. In other embodiments, if there are more than two voltage conversion modules, a corresponding overvoltage protection circuit 100 can be configured for each voltage conversion module.

[0077] In some embodiments, such as Figure 6 As shown, the power supply system 1000 also includes a third voltage conversion module 400, a controller 500, and a voltage detection module 600.

[0078] The third voltage conversion module 400 receives a second input voltage VI2 and converts it into a first input voltage VI1 during operation. The voltage detection module 600 receives a first output voltage VO1 and a second output voltage VO2 and outputs a first detection voltage based on VO1 and a second detection voltage based on VO2. The controller 500 is connected to the voltage detection module 600 and outputs a control signal to the third voltage conversion module 400 to stop its operation when the first detection voltage exceeds a second voltage threshold and / or the second detection voltage exceeds a third voltage threshold. The second and third voltage thresholds can be set based on the actual application scenario, requiring only that the first detection voltage exceeds the second voltage threshold and the second detection voltage exceeds the third voltage threshold during overvoltage.

[0079] In this embodiment, the controller 500 further controls the third voltage conversion module 400 to stop working during overvoltage, so that the third voltage conversion module 400 no longer outputs the first input voltage VI 1, thereby realizing the overvoltage protection function. That is, in this embodiment, not only is the overvoltage protection process realized through two overvoltage protection circuits 100, but the controller 500 also controls the third voltage conversion module 400 to stop working to realize the overvoltage protection process, thus realizing a dual overvoltage protection process, which has higher reliability and lower risk of device damage.

[0080] In some embodiments, the first voltage conversion module 200 is a DC-DC module, the second voltage conversion module 300 is an LDO module, and the third voltage conversion module 400 is a flyback power supply module.

[0081] Please refer to Figure 7 , Figure 7 To and Figure 6 The aforementioned block diagram corresponds to a circuit structure. The overvoltage protection circuit 100 can be referenced for... Figures 1-3 The explanation will not be repeated here. Figure 7 As shown, the voltage detection module 600 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a second capacitor C2, a third capacitor C3, a first Zener diode D1, and a second Zener diode D2.

[0082] In this circuit, the first terminal of the fifth resistor R5 receives the second output voltage VO2. The second terminal of the fifth resistor R5 is connected to the first terminals of the sixth resistor R6 and the seventh resistor R7. The second terminal of the seventh resistor R7 is connected to the anode of the first Zener diode D1 and the first terminal of the second capacitor C2. The cathode of the first Zener diode D1 receives the first output voltage VO1. The second terminals of the sixth resistor R6 and the second capacitor C2 are both grounded to GND. The first terminal of the eighth resistor R8 receives the first output voltage VO1. The second terminal of the eighth resistor R8 is connected to the first terminals of the ninth resistor R9 and the tenth resistor R10. The second terminal of the tenth resistor R10 is connected to the anode of the second Zener diode D2 and the first terminal of the third capacitor C3. The cathode of the second Zener diode D2 receives the first output voltage VO1. The second terminals of the ninth resistor R9 and the third capacitor C3 are both grounded to GND.

[0083] Specifically, the first output voltage VO1 is pulled up by the first Zener diode D1, and the first output voltage VO1 is pulled up by the second Zener diode D2; the second capacitor C2 and the third capacitor C3 are used for filtering; the seventh resistor R7 and the tenth resistor R10 are used for current limiting; the fifth resistor R5 and the sixth resistor R6 are used to divide the second output voltage VO2, and the second detection voltage is output to the controller 500 based on the voltage division of the second output voltage VO2 on the sixth resistor R6; the eighth resistor R8 and the ninth resistor R9 are used to divide the first output voltage VO1, and the first detection voltage is output to the controller 500 based on the voltage division of the first output voltage VO1 on the ninth resistor R9.

[0084] In this embodiment, the third voltage conversion module 400 includes a power management module 401, a main winding L11, and a flyback winding L12.

[0085] The power management module 401 is connected to both the controller 500 and the main winding L11. The main winding L11 also receives a second input voltage VI2. When the controller 500 controls the power management module 401 to run, the power management module 401 controls the charging and discharging process of the main winding L11 to convert the second input voltage VI2 into a first input voltage VI1, which is then output at the flyback winding L12. When the controller 500 stops the power management module 401 from running, the flyback winding L12 does not output voltage.

[0086] Figure 8 An example is shown Figure 7 The circuit shown has the overvoltage protection circuit 100 removed. Figure 7 The diagram shows the signals in the circuit. Among them, Figure 8 The (a1) part is Figure 8 The circuit shown is a schematic diagram of the signals in the circuit after removing the overvoltage protection circuit 100. Figure 8 The part (a2) in the middle is Figure 8 The diagram shows the signals in the circuit; the horizontal axis represents time T in μs; the vertical axis represents voltage in V; voltage VN1_1 is the voltage of the first node N1 in the first overvoltage protection circuit 100; voltage VN1_2 is the voltage of the second node N2 in the second overvoltage protection circuit 100.

[0087] Specifically, such as Figure 8 As shown in section (a1), around 12μs, the first input voltage VI 1 and the first output voltage VO1 are both adjusted to 12V to simulate an overvoltage anomaly; and the voltage VN1_1 and the second output voltage VO2 are both adjusted to 5V to simulate an overvoltage anomaly.

[0088] After setting up two overvoltage protection circuits 100, as follows Figure 8 As shown in section (a2), the voltage of the first node N1 in the first overvoltage protection circuit 100 is clamped to approximately 5V, and the voltage of the first node N1 in the second overvoltage protection circuit 100 is clamped to approximately 3.3V. It is evident that the voltages of the first nodes N1 in both the first and second overvoltage protection circuits are clamped to relatively low voltages to reduce the risk of damage to components (such as the second voltage conversion module 300). Furthermore, by adding a micro-branch, the clamping time for the voltage of the first node N1 can be approximately 630ns, which is short and has a fast response speed, facilitating rapid overvoltage protection.

[0089] This application also provides an energy storage device, which includes the overvoltage protection circuit 100 in any embodiment of this application, or the power supply system 1000 in any embodiment of this application.

[0090] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0091] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An overvoltage protection circuit, characterized in that, include: Switching modules, controllable voltage regulators, and voltage divider modules; The first terminal of the switching module is connected to the first terminal of the non-reference terminal of the controllable voltage regulator. The reference terminal of the controllable voltage regulator is connected to the second terminal of the voltage divider module at the second node. The first terminal of the voltage divider module is connected to the second terminal of the switching module at the first node. The second terminal of the non-reference terminal of the controllable voltage regulator and the third terminal of the voltage divider module are both grounded. The fourth terminal of the switching module receives a first voltage, and the third terminal of the switching module receives a second voltage. The switching module is used to turn on in response to the first voltage when the controllable voltage source is not turned on, so as to output the second voltage to the first node. The voltage divider module is used to divide the voltage of the first node, wherein when the switch module is turned on, the voltage divider module divides the second voltage and outputs a third voltage to the second node; The controllable voltage regulator is used to turn on in response to the third voltage being greater than the first voltage threshold, and to stabilize the voltage of the second node at the first voltage threshold. The switching module is also used to disconnect when the controllable voltage source is turned on; The voltage divider module is also used to clamp the voltage of the first node to a fourth voltage based on the first voltage threshold when the controllable voltage source is turned on.

2. The overvoltage protection circuit according to claim 1, characterized in that, The overvoltage protection circuit also includes a differentiating module; The differential module is connected between the first node and the second node, and the differential module is used to adjust the response speed of clamping the voltage of the first node.

3. The overvoltage protection circuit according to claim 1, characterized in that, The switching module includes a switching transistor and a first resistor; The first terminal of the switching transistor is connected to the first terminal of the non-reference terminal of the controllable voltage regulator and the first terminal of the first resistor, respectively. The second terminal of the first resistor is input with the first voltage. The second terminal of the switching transistor is connected to the first node. The third terminal of the switching transistor is input with the second voltage.

4. The overvoltage protection circuit according to claim 1, characterized in that, The voltage divider module includes a second resistor and a third resistor; The second resistor and the third resistor are connected in series between the first node and ground, and the connection point between the second resistor and the third resistor is the second node.

5. The overvoltage protection circuit according to claim 2, characterized in that, The differentiating module includes a fourth resistor and a first capacitor; The fourth resistor is connected in series with the first capacitor between the first node and the second node.

6. A power supply system, characterized in that, include: The first voltage conversion module receives a first input voltage and converts the first input voltage into a first output voltage. The first overvoltage protection circuit as described in any one of claims 1-5 is connected to the first voltage conversion module, wherein the first voltage input to the first overvoltage protection circuit is the first input voltage, and the second voltage input to the first overvoltage protection circuit is the first output voltage.

7. The power supply system according to claim 6, characterized in that, The power supply system also includes: The second voltage conversion module takes the first output voltage as input and converts the first output voltage into the second output voltage. The second overvoltage protection circuit as described in any one of claims 1-5 is connected to the second voltage conversion module, wherein the first voltage input to the second overvoltage protection circuit is the first input voltage, and the second voltage input to the first overvoltage protection circuit is the second output voltage.

8. The power supply system according to claim 7, characterized in that, The power supply system also includes: The third voltage conversion module receives a second input voltage and converts the second input voltage into the first input voltage during its operation. The voltage detection module takes the first output voltage and the second output voltage as input, and outputs a first detection voltage based on the first output voltage and a second detection voltage based on the second output voltage. The controller, connected to the voltage detection module, is used to output a control signal to the third voltage conversion module when the first detected voltage is greater than the second voltage threshold and / or the second detected voltage is greater than the third voltage threshold, so as to stop the third voltage conversion module from working.

9. The power supply system according to claim 8, characterized in that, The voltage detection module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second capacitor, a third capacitor, a first Zener diode, and a second Zener diode; The first terminal of the fifth resistor is input to the second output voltage. The second terminal of the fifth resistor is connected to the first terminal of the sixth resistor and the first terminal of the seventh resistor. The second terminal of the seventh resistor is connected to the anode of the first Zener diode and the first terminal of the second capacitor. The cathode of the first Zener diode is input to the first output voltage. The second terminal of the sixth resistor and the second terminal of the second capacitor are both grounded. The first terminal of the eighth resistor receives the first output voltage, the second terminal of the eighth resistor is connected to the first terminal of the ninth resistor and the first terminal of the tenth resistor, the second terminal of the tenth resistor is connected to the anode of the second Zener diode and the first terminal of the third capacitor, the cathode of the second Zener diode receives the first output voltage, and the second terminal of the ninth resistor and the second terminal of the third capacitor are both grounded.

10. An energy storage device, characterized in that, It includes the overvoltage protection circuit as described in any one of claims 1-5 or the power supply system as described in any one of claims 6-9.

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