Surge protection circuit and automobile controller system

Abstract

The utility model relates to a surge protection circuit and an automobile controller system, and relates to the technical field of automobiles. The circuit comprises at least one surge protection sub-circuit, and each surge protection sub-circuit is connected with a bus. The surge protection sub-circuit comprises a first surge sub-circuit and a second surge sub-circuit. The first end, the second end and the control end of the first surge sub-circuit are electrically connected with the bus, the first voltage end and the second voltage end respectively. The first end, the second end and the control end of the second surge sub-circuit are electrically connected with the bus, the first voltage end and the third voltage end respectively. When the difference between the voltage of the signal transmitted by the bus and the voltage of the second voltage end is greater than or equal to a first threshold value, the first surge sub-circuit clamps the voltage on the bus to a first safety voltage. And when the difference between the voltage of the third voltage end and the voltage of the signal transmitted by the bus is greater than or equal to a second threshold value, the second surge sub-circuit clamps the voltage on the bus to a second safety voltage.

Description

Technical Field

[0001] This application relates to the field of automotive technology, in particular to the field of automotive surge protection technology, and specifically relates to a surge protection circuit and an automotive controller system. Background Art

[0002] The increasing intelligence and networking of new energy vehicles have led to a higher degree of integration of in-vehicle electronic and electrical appliances. On the one hand, the highly integrated electronic and electrical appliances bring users a richer usage experience. On the other hand, it also causes the frequency of electronic interference received by new energy vehicle controllers to be higher and higher.

[0003] These electronic interferences often invade the interior of the vehicle controller in the form of surges through the power supply port or signal port of the vehicle controller, causing irreversible damage to the vehicle controller. Utility Model Content

[0004] One of the purposes of this application is to provide a surge protection circuit and an automotive controller system for realizing surge protection.

[0005] To achieve the above purpose, the technical solution adopted in this application is as follows:

[0006] According to the first aspect of this application, a surge protection circuit is provided, including: at least one surge protection sub-circuit, and each surge protection sub-circuit is connected to a bus. The surge protection sub-circuit includes: a first surge sub-circuit and a second surge sub-circuit. The first end of the first surge sub-circuit is electrically connected to the bus, the second end of the first surge sub-circuit is electrically connected to the first voltage terminal, and the control end of the first surge sub-circuit is electrically connected to the second voltage terminal. The first end of the second surge sub-circuit is electrically connected to the bus, the second end of the second surge sub-circuit is electrically connected to the first voltage terminal, and the control end of the second surge sub-circuit is electrically connected to the third voltage terminal. The first surge sub-circuit is configured to: when the voltage difference between the voltage of the signal transmitted on the bus and the voltage of the second voltage terminal is greater than or equal to the first threshold, conduct between the bus and the second voltage terminal, and clamp the voltage on the bus to the first safety voltage. The second surge sub-circuit is configured to: when the voltage difference between the voltage of the third voltage terminal and the voltage of the signal transmitted on the bus is greater than or equal to the second threshold, conduct between the bus and the third voltage terminal, and clamp the voltage on the bus to the second safety voltage.

[0007] When the voltage difference between the voltage of the signal transmitted on the bus and the voltage of the second voltage terminal is greater than or equal to the first threshold, a positive surge voltage is transmitted from the bus at this time. The first surge sub-circuit conducts between the bus and the second voltage terminal, discharges the positive surge voltage along the path from the bus to the second voltage terminal, and finally clamps the positive surge voltage at the first safe voltage. When the voltage difference between the voltage of the third voltage terminal and the voltage of the signal transmitted on the bus is greater than or equal to the second threshold, a negative surge voltage is transmitted from the bus at this time. The second surge sub-circuit conducts between the bus and the third voltage terminal, discharges the negative surge voltage along the path from the bus to the third voltage terminal, and finally clamps the negative surge voltage at the second safe voltage. Thus, whether a positive surge voltage or a negative surge voltage is generated on the bus, there is a corresponding path in the surge protection circuit to discharge the surge voltage, ensuring that the voltage of the signal output on the bus is always within the safe voltage, protecting the safety of the remaining devices connected to the bus, and realizing the protection against surges.

[0008] In a possible implementation, the first surge sub-circuit is further configured to: turn off the connection between the bus and the second voltage terminal when the voltage difference between the voltage of the signal transmitted on the bus and the voltage of the second voltage terminal is less than the first threshold. The second surge sub-circuit is further configured to: turn off the connection between the bus and the third voltage terminal when the voltage difference between the voltage of the third voltage terminal and the voltage of the signal transmitted on the bus is less than the second threshold.

[0009] In a possible implementation, the first surge sub-circuit includes: a first unidirectional thyristor, a first triode, and a first bidirectional transient voltage suppressor diode. The anode of the first unidirectional thyristor is electrically connected to the first end of the first surge sub-circuit, the cathode of the first unidirectional thyristor is electrically connected to one end of the first bidirectional transient voltage suppressor diode, the other end of the first bidirectional transient voltage suppressor diode is electrically connected to the second end of the first surge sub-circuit, the control electrode of the first unidirectional thyristor is electrically connected to the emitter of the first triode, the base of the first triode is electrically connected to the control terminal of the first surge sub-circuit, and the collector of the first triode is electrically connected to the second end of the first surge sub-circuit.

[0010] In a possible implementation, the second surge sub-circuit includes: a second unidirectional thyristor, a second triode, and a second bidirectional transient voltage suppressor diode. The cathode of the second unidirectional thyristor is electrically connected to the first end of the second surge sub-circuit, the anode of the second unidirectional thyristor is electrically connected to one end of the second bidirectional transient voltage suppressor diode, the other end of the second bidirectional transient voltage suppressor diode is electrically connected to the second end of the second surge sub-circuit, the control electrode of the second unidirectional thyristor is electrically connected to the emitter of the second triode, the base of the second triode is electrically connected to the control terminal of the second surge sub-circuit, and the collector of the second triode is electrically connected to the second end of the second surge sub-circuit.

[0011] In a possible implementation, the output voltage of the second voltage terminal is adjustable, and the output voltage of the third voltage terminal is adjustable.

[0012] In a possible implementation, the withstand voltage between the emitter and collector of the first triode is greater than the rated output voltage of the bus, and the withstand voltage between the emitter and collector of the first triode is greater than the first safety voltage. The withstand voltage between the emitter and collector of the second triode is greater than the rated output voltage of the bus, and the withstand voltage between the emitter and collector of the second triode is greater than the second safety voltage.

[0013] In a possible implementation, the maximum reverse operating voltage of the first bidirectional transient voltage suppressor diode is equal to or less than the rated output voltage of the bus, and the maximum reverse operating voltage of the second bidirectional transient voltage suppressor diode is equal to or less than the rated output voltage of the bus.

[0014] In a possible implementation, the withstand voltage between the anode and cathode of the first unidirectional thyristor is greater than the rated output voltage of the bus, and the withstand voltage between the anode and cathode of the first unidirectional thyristor is greater than the first safety voltage. The withstand voltage between the anode and cathode of the second unidirectional thyristor is greater than the rated output voltage of the bus, and the withstand voltage between the anode and cathode of the second unidirectional thyristor is greater than the second safety voltage.

[0015] In a possible implementation, the surge protection circuit includes two surge protection sub - circuits, and each surge protection sub - circuit is connected to a bus. The two surge protection sub - circuits include a first surge protection sub - circuit and a second surge protection sub - circuit. The first surge protection sub - circuit is electrically connected to the first bus, and the second surge protection sub - circuit is electrically connected to the second bus.

[0016] According to the second aspect provided by the present application, there is provided an automotive controller system, including the surge protection circuit as described in the first aspect and its possible implementations, and an automotive controller. The automotive controller is connected to the bus and is connected in parallel with the surge protection circuit. Description of the Drawings

[0017] The drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solutions of the present invention, and do not constitute a limitation to the technical solutions of the present invention.

[0018] Figure 1 It is a schematic diagram of a surge protection sub - circuit provided by an embodiment of the present application;

[0019] Figure 2 It is a schematic diagram of a first surge sub - circuit provided by an embodiment of the present application;

[0020] Figure 3 Schematic diagram of a second surge sub - circuit provided by an embodiment of the present application;

[0021] Figure 4 Schematic diagram of a surge protection circuit provided by an embodiment of the present application;

[0022] Figure 5 Schematic diagram of an automotive controller system provided by an embodiment of the present application;

[0023] Figure 6 Schematic diagram of another automotive controller system provided by an embodiment of the present application. Detailed implementation manners

[0024] The following will illustrate the implementation manners of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for explaining the present application and not for limiting the protection scope of the present application.

[0025] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. Therefore, only the components related to the present application are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0026] In the description of the embodiments, unless otherwise specified, " / " means "or". For example, A / B can represent A or B. The "and / or" herein is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, "at least one" and "multiple" refer to two or more. The words such as "first" and "second" do not limit the quantity and execution order, and the words such as "first" and "second" do not necessarily limit to be different.

[0027] With the gradual reduction of fossil energy and the increasing environmental problems, the development of new energy has become an irresistible trend, and new energy vehicles have also become the development direction of the automotive industry. Against this background, each automotive enterprise is developing its own new energy vehicle technology. The integration degree of the electronic and electrical architecture inside new energy vehicles is getting higher and higher, making the intelligence and networking degree of new energy vehicles also getting higher and higher. While the highly integrated electronic and electrical appliances bring users a richer usage experience, they also cause the frequency of electronic interference to the new energy vehicle controller to be higher and higher. These electronic interferences often invade the interior of the vehicle controller in the form of surges through the power supply port or signal port of the vehicle controller, causing irreversible damage to the vehicle controller.

[0028] Moreover, the new energy vehicle controller plays an important role in the whole vehicle. The new energy vehicle controller is responsible for the normal driving of the vehicle, braking energy regeneration, energy management of the whole vehicle drive system and power battery, network management, fault diagnosis and handling, vehicle status monitoring, etc., so as to ensure that the whole vehicle works normally and stably under the conditions of good power performance, high economy and reliability. Once the vehicle controller is damaged, users need to spend a lot of time and money costs.

[0029] In view of this, the present application provides a surge protection circuit. The surge protection circuit includes at least one surge protection sub-circuit, and each surge protection sub-circuit is connected to a bus. Exemplarily, taking the surge protection circuit composed of one surge protection sub-circuit as an example for illustration, as Figure 1 shown. Referring to Figure 1 , the surge protection sub-circuit includes a first surge sub-circuit 3 and a second surge sub-circuit 2. The first surge sub-circuit 3 includes a first end 3-1, a second end 3-2 and a control end 3-3. The second surge sub-circuit 2 includes a first end 2-1, a second end 2-2 and a control end 2-3.

[0030] The first end 3-1 of the first surge sub-circuit 3 is electrically connected to the first bus 1, and the first bus 1 belongs to one of many buses. The second end 3-2 of the first surge sub-circuit 3 is electrically connected to the first voltage terminal GND. The control end 3-3 of the first surge sub-circuit 3 is electrically connected to the second voltage terminal VDD. The first end 2-1 of the second surge sub-circuit 2 is electrically connected to the first bus 1, the second end 2-2 of the second surge sub-circuit 2 is electrically connected to the first voltage terminal GND, and the control end 2-3 of the second surge sub-circuit 2 is electrically connected to the third voltage terminal VCC.

[0031] The first surge sub-circuit 3 is configured to: when the voltage difference between the voltage of the signal transmitted on the first bus 1 and the voltage of the second voltage terminal VDD is greater than or equal to the first threshold, conduct between the first bus 1 and the second voltage terminal VDD, and clamp the voltage on the first bus 1 to the first safe voltage. The second surge sub-circuit 2 is configured to: when the voltage difference between the voltage of the third voltage terminal VCC and the voltage of the signal transmitted on the first bus 1 is greater than or equal to the second threshold, conduct between the first bus 1 and the third voltage terminal VCC, and clamp the voltage on the first bus 1 to the second safe voltage.

[0032] When the voltage difference between the voltage of the signal transmitted on the first bus 1 and the voltage of the second voltage terminal VDD is greater than or equal to the first threshold, at this time, the positive surge voltage is transmitted from the first bus 1. The first surge sub-circuit 3 conducts between the first bus 1 and the second voltage terminal VDD, and discharges the positive surge voltage through the path from the first bus 1 to the second voltage terminal VDD, and finally clamps the positive surge voltage to the first safe voltage. When the voltage difference between the voltage of the third voltage terminal VCC and the voltage of the signal transmitted on the first bus 1 is greater than or equal to the second threshold, at this time, the negative surge voltage is transmitted from the first bus 1. The second surge sub-circuit 2 conducts between the first bus 1 and the third voltage terminal VCC, and discharges the negative surge voltage through the path from the first bus 1 to the third voltage terminal VCC, and finally clamps the negative surge voltage to the second safe voltage. Thus, whether a positive surge voltage or a negative surge voltage is generated on the first bus 1, there is a corresponding path in the surge protection circuit to discharge the surge voltage, ensuring that the voltage of the signal output on the first bus 1 is always within the safe voltage, protecting the safety of the remaining devices connected to the first bus 1, and realizing the protection against surges.

[0033] In practical applications, there are usually more than one bus. For example, the interface of the vehicle controller is connected to the power bus and various signal buses, and each bus connected to the interface of the vehicle controller may generate a surge voltage. Since the surge protection circuit includes at least one surge protection sub-circuit, and each surge protection sub-circuit is connected to one bus, each surge protection sub-circuit can protect the corresponding bus. When a positive surge voltage appears on any bus, the first surge sub-circuit of the corresponding connected surge protection sub-circuit will clamp the surge voltage on the bus to the first safe voltage. When a negative surge voltage appears on any bus, the second surge sub-circuit of the corresponding connected surge protection sub-circuit will clamp the surge voltage on the bus to the second safe voltage. Therefore, the protection against surges is realized, and the safety and stability of the vehicle are improved.

[0034] As a possible implementation, the first surge sub-circuit is further configured to turn off the connection between the bus and the second voltage terminal when the difference between the voltage of the signal transmitted on the bus and the voltage of the second voltage terminal is less than the first threshold. The second surge sub-circuit is further configured to turn off the connection between the bus and the third voltage terminal when the difference between the voltage of the third voltage terminal and the voltage of the signal transmitted on the bus is less than the second threshold.

[0035] When the voltage of the signal transmitted on the bus is normal, no path is formed between the bus and the second voltage terminal, and the signal cannot be transmitted from the first end of the first surge sub-circuit to the second end of the first surge sub-circuit, nor can the signal be transmitted from the first end of the second surge sub-circuit to the second end of the second surge sub-circuit. Once the signal transmitted on the bus is abnormal, that is, a surge voltage appears, the signal can be transmitted from the first end of the first surge sub-circuit to the second end of the first surge sub-circuit, or from the first end of the second surge sub-circuit to the second end of the second surge sub-circuit. When the surge voltage on the bus is discharged and returns to the normal voltage, the mission of the surge protection circuit has been accomplished. In order not to affect the normal operation of the components connected in parallel with the bus, the connection between the bus and the second voltage terminal will be turned off again.

[0036] In some embodiments, as Figure 2 shown, Figure 2 shows the composition of the first surge sub-circuit. Referring to Figure 2 , the first surge sub-circuit 3 includes: a first unilateral thyristor 31, a first triode 32, and a first bidirectional transient voltage suppressor diode 33. The anode of the first unilateral thyristor 31 is electrically connected to the first end 3-1 of the first surge sub-circuit 3, the cathode of the first unilateral thyristor 31 is electrically connected to one end of the first bidirectional transient voltage suppressor diode 33, the other end of the first bidirectional transient voltage suppressor diode 33 is electrically connected to the second end 3-2 of the first surge sub-circuit 3, the control electrode of the first unilateral thyristor 31 is electrically connected to the emitter of the first triode 32, the base of the first triode 32 is electrically connected to the control terminal 3-3 of the first surge sub-circuit 3, and the collector of the first triode 32 is electrically connected to the second end 3-2 of the first surge sub-circuit 3.

[0037] Exemplarily, taking Figure 2 as an example, the first unilateral thyristor 31 in the first surge sub-circuit 3 has an internal structure of four layers and three junctions of NPNP type, and the first triode 32 is a PNP type triode.

[0038] The thyristor is a controllable rectifier electronic component that can be turned from off to on under the action of an external control signal. However, once it is turned on, the external signal cannot turn it off, and it can only be turned off by removing the load or reducing the voltage across it. The control electrode of the first thyristor 31 is connected to the emitter of the first triode 32. The first triode 32 is in the cut-off state when the voltage of the signal transmitted on the first bus 1 is normal. Therefore, the first thyristor 31 has no external control signal to control its change from the off state to the on state, that is, no current from the emitter of the first triode 32 is transmitted to the control electrode of the first thyristor 31, making the anode and cathode of the first thyristor 31 conduct.

[0039] The first threshold is also the turn-on voltage of the first triode 32. When a surge voltage appears on the first bus 1 and the difference between the voltage of the signal transmitted on the first bus 1 and the voltage of the second voltage terminal VDD is greater than or equal to the first threshold, that is, greater than the turn-on voltage of the first triode 32, it means that the voltage of the signal transmitted on the first bus 1 is greater than or equal to the voltage of the second voltage terminal VDD. At this time, the positive surge voltage is transmitted from the first bus 1. Since this voltage reaches the turn-on voltage of the first triode 32, the first triode 32 changes from the cut-off state to the on state, and a current path is formed from the emitter to the collector of the first triode 32. Also, since the control electrode of the first thyristor 31 is electrically connected to the emitter of the first triode 32, this current becomes the external control signal of the first thyristor 31, making the first thyristor 31 change from the off state to the on state, and the surge voltage transmitted on the first bus 1 is transmitted to the first bidirectional transient voltage suppressor diode 33.

[0040] The characteristic of the bidirectional transient voltage suppressor diode is that when a spike voltage (i.e., surge voltage) comes, the impedance of the bidirectional transient voltage suppressor diode will change from a higher state to a lower state, so that the energy of the spike voltage is dissipated through the bidirectional transient voltage suppressor diode. Therefore, when the surge voltage transmitted on the first bus 1 is transmitted to the first bidirectional transient voltage suppressor diode 33, the energy of the surge voltage can be dissipated by the first bidirectional transient voltage suppressor diode 33, and finally the positive surge voltage is clamped at the first safety voltage.

[0041] Since the surge voltage is a severe pulse within a short period of time, after the voltage of the signal transmitted by the first bus 1 returns to normal, relying solely on the rated working voltage of the first bus 1 cannot maintain the first bidirectional transient suppression diode 33 in the conducting state. Therefore, the first bidirectional transient suppression diode 33 resumes to the high-resistance state, thereby blocking the current between the cathode of the first thyristor 31 and the first voltage terminal GND. Further, the first thyristor 31 is turned off and the first triode 32 is cut off. At this time, the voltage difference between the voltage of the signal transmitted by the first bus 1 and the voltage of the second voltage terminal VDD is less than the first threshold, and the connection between the first bus 1 and the second voltage terminal VDD is turned off. The entire circuit returns to the high-resistance state before the surge and waits for the next surge to occur.

[0042] In some embodiments, as Figure 3 shown, Figure 3 shows the composition of the second surge sub-circuit. Referring to Figure 3 , the second surge sub-circuit 2 includes: a second thyristor 21, a second triode 22, and a second bidirectional transient suppression diode 23. The cathode of the second thyristor 21 is electrically connected to the first end 2-1 of the second surge sub-circuit 2, the anode of the second thyristor 21 is electrically connected to one end of the second bidirectional transient suppression diode 23, the other end of the second bidirectional transient suppression diode 23 is electrically connected to the second end 2-2 of the second surge sub-circuit 2, the control electrode of the second thyristor 21 is electrically connected to the emitter of the second triode 22, the base of the second triode 22 is electrically connected to the control terminal of the second surge sub-circuit 2, and the collector of the second triode 22 is electrically connected to the second end of the second surge sub-circuit 2.

[0043] Exemplarily, taking Figure 3 as an example, the second thyristor 21 in the second surge sub-circuit 2 has an internal structure of a PNPN type four-layer three-junction, and the second triode 22 is an NPN type triode.

[0044] The second threshold, which is also the conduction voltage of the second triode 22, indicates that the voltage of the third voltage terminal VCC is greater than or equal to the voltage of the signal transmitted by the first bus 1 when the difference between the voltage of the third voltage terminal VCC and the voltage of the signal transmitted by the first bus 1 is greater than or equal to the second threshold, that is, greater than the conduction voltage of the second triode 33. At this time, a negative surge voltage is transmitted from the first bus 1. Since this voltage reaches the conduction voltage of the second triode 22, the second triode 22 changes from the cut-off state to the conduction state, and a current path is formed between the emitter and the collector of the second triode 22. Also, since the control electrode of the second unilateral thyristor 21 is electrically connected to the emitter of the second triode 22, this current becomes the external control signal of the second unilateral thyristor 21, causing the second unilateral thyristor 21 to change from the off state to the on state, and the surge voltage transmitted by the first bus 1 is transmitted to the second bidirectional transient voltage suppressor diode 23. The energy of the surge voltage can be dissipated by the second bidirectional transient voltage suppressor diode 23, and finally the negative surge voltage is clamped at the first safety voltage.

[0045] Since the surge voltage is a sharp pulse within a short period of time, when the voltage of the signal transmitted by the first bus 1 returns to normal, the rated working voltage of the first bus 1 alone cannot maintain the second bidirectional transient voltage suppressor diode 23 in the conducting state. Therefore, the second bidirectional transient voltage suppressor diode 23 resumes to the high-resistance state, thereby blocking the current between the cathode of the second unilateral thyristor 21 and the first voltage terminal GND, further causing the second unilateral thyristor 21 to turn off and the second triode 22 to cut off. At this time, the difference between the voltage of the third voltage terminal VCC and the voltage of the signal transmitted by the first bus 1 is less than the first threshold, and the connection between the first bus 1 and the third voltage terminal VCC is turned off. The entire circuit returns to the high-resistance state before the surge and waits for the next surge to come.

[0046] As a possible implementation, the output voltage of the second voltage terminal is adjustable, and the output voltage of the third voltage terminal is adjustable. Since the current between the emitter and the collector of the first triode is the external control signal of the control electrode of the first unilateral thyristor, and whether there is a current between the emitter and the collector of the first triode depends on whether the voltage difference between the first bus and the base of the first triode is greater than the conduction voltage, and the voltage of the base of the first triode is controlled by the output voltage of the second voltage terminal, the protection level of the surge protection circuit can be controlled by adjusting the voltage output of the second voltage terminal. For example, the higher the voltage output of the second voltage terminal is adjusted, the higher the protection standard is. Taking the conduction voltage of the first triode as 0.7v as an example, when the voltage output of the second voltage terminal is 10v, a voltage above 10.7v is considered a surge voltage, and when the voltage output of the second voltage terminal is 20v, a voltage above 20.7v is considered a surge voltage. The principle of the adjustable third voltage terminal is the same, and will not be elaborated here.

[0047] By adjusting the output voltages of the second voltage terminal and the third voltage terminal, the programmability of surge protection is achieved. When the standard of surge protection needs to be improved, only the output voltages of the second voltage terminal and the third voltage terminal need to be increased. When the standard of surge protection needs to be reduced, only the output voltages of the second voltage terminal and the third voltage terminal need to be decreased. The generalization of surge protection for different buses connected to different ports of the vehicle controller is realized, thus improving the flexibility of the surge protection circuit.

[0048] It should be noted that, in order to ensure the normal operation of the first triode and the second triode, the breakdown voltage between the emitter and the collector of the first triode should be greater than the rated output voltage of the bus, and the breakdown voltage between the emitter and the collector of the first triode should be greater than the first safety voltage; the breakdown voltage between the emitter and the collector of the second triode should be greater than the rated output voltage of the bus, and the breakdown voltage between the emitter and the collector of the second triode should be greater than the second safety voltage, so as to prevent the first triode and the second triode from being broken down when the voltage of the signal output by the bus is normal, or when the surge voltage on the bus is clamped at the safety voltage.

[0049] It should be noted that, in order to ensure that the first bidirectional transient suppression diode is in a low-resistance state when the first unidirectional thyristor is conducting, and the second bidirectional transient suppression diode is in a low-resistance state when the second unidirectional thyristor is conducting, the maximum reverse operating voltage of the first bidirectional transient suppression diode should be equal to or less than the rated output voltage of the bus, and the maximum reverse operating voltage of the second bidirectional transient suppression diode should be equal to or less than the rated output voltage of the bus.

[0050] It should be noted that, in order to enable the first unidirectional thyristor and the second unidirectional thyristor to operate normally and prevent the first unidirectional thyristor and the second unidirectional thyristor from being broken down when the voltage of the signal output by the bus is normal or when the surge voltage on the bus is clamped at the safety voltage, the breakdown voltage between the anode and the cathode of the first unidirectional thyristor should be greater than the rated output voltage of the bus, and the breakdown voltage between the anode and the cathode of the first unidirectional thyristor should be greater than the first safety voltage. The breakdown voltage between the anode and the cathode of the second unidirectional thyristor should be greater than the rated output voltage of the bus, and the breakdown voltage between the anode and the cathode of the second unidirectional thyristor should be greater than the second safety voltage.

[0051] It should be understood that the rated output voltage of the above-mentioned bus refers to the normal output voltage of the bus.

[0052] In some embodiments, such as Figure 4As shown, the surge protection circuit includes two surge protection sub - circuits, the first surge protection sub - circuit 10 and the second surge protection sub - circuit 20. Each surge protection sub - circuit is connected to a bus. The first surge protection sub - circuit 10 is electrically connected to the first bus 1, and the second surge protection sub - circuit 20 is electrically connected to the second bus 4. Among them, the composition, structure and connection relationship of the first surge protection sub - circuit 10 and the second surge protection sub - circuit 20 are the same. Each surge protection sub - circuit is composed of two unilateral thyristors, two triodes and two bidirectional transient voltage suppressors.

[0053] Adopt Figure 4 The surge protection circuit shown can protect the vehicle controller from the surge voltages that may appear on the first bus and the second bus. The first surge protection sub - circuit protects the vehicle controller from the surge voltage that may appear on the first bus, and the second surge protection sub - circuit protects the vehicle controller from the surge voltage that may appear on the second bus. Figure 3 The surge protection circuit shown is different from Figure 4 the surge protection circuit shown in that the number of surge protection sub - circuits included is different. When the vehicle controller needs to be connected to two buses, 2 Figure 3 surge protection circuits shown are respectively connected to two different buses.

[0054] By adjusting the output voltages of the second voltage terminal and the third voltage terminal, the programmability of surge protection is realized. Due to the internal structure of the four - layer three - junction (PNPN or NPNP) of the unilateral thyristor and the series connection with the bidirectional transient voltage suppressor, it can, to the greatest extent, meet the signal transmission on the bus while reducing the influence of capacitance on communication.

[0055] This application also provides a vehicle controller system. Exemplarily, as Figure 5 shown. Referring to Figure 5 , the vehicle controller system 100 includes the surge protection circuit 30 as described above and the vehicle controller 40. The vehicle controller 40 is connected to the bus, and the vehicle controller 40 is connected in parallel with the surge protection circuit 30. For example, the first bus 1 is a power line. The power supply port 40 - 1 of the vehicle controller 40 is electrically connected to the first bus 1, and the ground port 40 - 2 of the vehicle controller 40 is electrically connected to the first voltage terminal GND. When a positive surge voltage occurs on the first bus 1, the energy generated by the positive surge voltage is dissipated through the first surge sub - circuit 3 of the surge protection circuit. When a negative surge voltage occurs on the first bus 1, the energy generated by the negative surge voltage is dissipated through the second surge sub - circuit 2 of the surge protection circuit, ensuring the safety of the vehicle controller 40.

[0056] Again, for example, referring to Figure 6, the first bus 1 is a power line, the second bus 2 is a signal line. The power supply port 40-1 of the vehicle controller 40 is electrically connected to the first bus 1, the grounding port 40-2 of the vehicle controller 40 is electrically connected to the first voltage terminal GND, and the signal port 40-3 of the vehicle controller 40 is electrically connected to the second bus 2. At this time, when a positive surge voltage is generated on the power line, the energy generated by the positive surge voltage is discharged through the first surge sub-circuit 3 in the surge protection circuit 30 connected to the first bus 1. When a negative surge voltage is generated on the power line, the energy generated by the negative surge voltage is discharged through the second surge sub-circuit 2 in the surge protection circuit 30 connected to the first bus 1. When a positive surge voltage is generated on the signal line, the energy generated by the positive surge voltage is discharged through the first surge sub-circuit 3 in the surge protection circuit 30 connected to the second bus 2. When a negative surge voltage is generated on the signal line, the energy generated by the negative surge voltage is discharged through the second surge sub-circuit 2 in the surge protection circuit 30 connected to the second bus 2.

[0057] When applied to the vehicle controller system, due to the existence of the bidirectional transient suppression diode, the surge voltage can be clamped within a safe range, so as not to excessively pull down the potential on the bus and cause the system to power off and restart. Also because of the existence of the bidirectional transient suppression diode, after the surge, the current in the discharge path can be blocked, prompting the unidirectional thyristor to turn off, and solving the problem of thyristor freewheeling.

[0058] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any change or replacement within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A surge protection circuit, characterized in that: include: at least one surge protection subcircuit, each of the surge protection subcircuit being connected to a bus; The surge protection subcircuit comprises: a first surge sub-circuit and a second surge sub-circuit; A first end of the first surge sub-circuit is electrically connected to the bus, a second end of the first surge sub-circuit is electrically connected to a first voltage end, and a control end of the first surge sub-circuit is electrically connected to a second voltage end; The first end of the second surge sub-circuit is electrically connected to the bus, the second end of the second surge sub-circuit is electrically connected to the first voltage end, and the control end of the second surge sub-circuit is electrically connected to the third voltage end; The first surge subcircuit is configured to: when the difference between the voltage of the signal transmitted by the bus and the voltage of the second voltage terminal is greater than or equal to a first threshold, conduct the bus and the second voltage terminal to clamp the voltage on the bus to a first safety voltage; The second surge subcircuit is configured to conduct between the bus and the third voltage terminal and clamp the voltage on the bus to a second safety voltage when the difference between the voltage at the third voltage terminal and the voltage of the signal transmitted by the bus is greater than or equal to a second threshold.

2. The surge protection circuit according to claim 1, characterized in that: The first surge sub-circuit is further configured to: when the difference between the voltage of the signal transmitted by the bus and the voltage of the second voltage terminal is less than a first threshold, disconnect the bus from the second voltage terminal; The second surge sub-circuit is further configured to disconnect the bus from the third voltage terminal when the difference between the voltage of the third voltage terminal and the voltage of the signal transmitted by the bus is less than a second threshold.

3. The surge protection circuit according to claim 2, characterized in that: The first surge sub-circuit includes: a first unidirectional thyristor, a first transistor and a first bidirectional transient suppression diode; An anode of the first unidirectional thyristor is electrically connected to a first end of the first surge sub-circuit, a cathode of the first unidirectional thyristor is electrically connected to one end of the first bidirectional transient suppression diode, the other end of the first bidirectional transient suppression diode is electrically connected to a second end of the first surge sub-circuit, a control electrode of the first unidirectional thyristor is electrically connected to an emitter of the first transistor, a base of the first transistor is electrically connected to a control end of the first surge sub-circuit, and a collector of the first transistor is electrically connected to a second end of the first surge sub-circuit.

4. The surge protection circuit according to claim 3, characterized in that: The second surge sub-circuit includes: a second unidirectional thyristor, a second triode and a second bidirectional transient suppression diode; The cathode of the second unidirectional thyristor is electrically connected to the first end of the second surge sub-circuit, the anode of the second unidirectional thyristor is electrically connected to one end of the second bidirectional transient suppression diode, the other end of the second bidirectional transient suppression diode is electrically connected to the second end of the second surge sub-circuit, the control electrode of the second unidirectional thyristor is electrically connected to the emitter of the second transistor, the base of the second transistor is electrically connected to the control end of the second surge sub-circuit, and the collector of the second transistor is electrically connected to the second end of the second surge sub-circuit.

5. The surge protection circuit according to claim 1, characterized in that: The output voltage of the second voltage terminal is adjustable, and the output voltage of the third voltage terminal is adjustable.

6. The surge protection circuit according to claim 4, characterized in that: The withstand voltage value between the emitter and the collector of the first transistor is greater than the rated output voltage of the bus, and the withstand voltage value between the emitter and the collector of the first transistor is greater than the first safety voltage; The withstand voltage value between the emitter and the collector of the second transistor is greater than the rated output voltage of the bus, and the withstand voltage value between the emitter and the collector of the second transistor is greater than the second safety voltage.

7. The surge protection circuit according to claim 6, characterized in that: The maximum reverse operating voltage of the first bidirectional transient suppression diode is equal to or less than the rated output voltage of the bus; The maximum reverse operating voltage of the second bidirectional transient suppression diode is equal to or less than a rated output voltage of the bus.

8. The surge protection circuit according to claim 7, characterized in that: The withstand voltage between the anode and cathode of the first unidirectional thyristor is greater than the rated output voltage of the bus, and the withstand voltage between the anode and cathode of the first unidirectional thyristor is greater than the first safety voltage; The withstand voltage between the anode and cathode of the second unidirectional thyristor is greater than the rated output voltage of the bus, and the withstand voltage between the anode and cathode of the second unidirectional thyristor is greater than the second safety voltage.

9. The surge protection circuit according to any one of claims 1 to 8, characterized in that: include: Two surge protection sub-circuits, each of the surge protection sub-circuits being connected to a bus; The two surge protection sub-circuits include a first surge protection sub-circuit and a second surge protection sub-circuit, the first surge protection sub-circuit is electrically connected to the first bus, and the second surge protection sub-circuit is electrically connected to the second bus.

10. An automobile controller system, characterized in that: include: The surge protection circuit and the automobile controller according to any one of claims 1 to 9, wherein the automobile controller is connected to a bus, and the automobile controller is connected in parallel to the surge protection circuit.

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