阅读说明：本技术 汽车电路保护装置、系统和方法 (Automobile circuit protection device, system and method ) 是由 张相旻 姚志豪 杜祖楠 于 2020-05-11 设计创作，主要内容包括：本发明涉及汽车电路保护装置、系统和方法。汽车电路保护装置包括：保护型金属氧化物半导体场效应晶体管PROFET；以及控制器,其连接到PROFET；其中,控制器配置成：从PROFET接收反馈信号；以及基于反馈信号生成控制信号并向PROFET发送控制信号,控制信号使得PROFET控制汽车电路的负载的电流。汽车电路保护方法包括：从PROFET接收反馈信号；以及基于反馈信号生成控制信号并向PROFET发送控制信号,控制信号使得PROFET控制汽车电路中的电流。汽车电路保护系统包括：接收模块,其配置成从PROFET接收反馈信号；计算模块,其配置成基于反馈信号生成控制信号,控制信号使得PROFET控制汽车电路的负载的电流；以及发射模块,其配置成向PROFET发送控制信号。(The invention relates to an automobile circuit protection device, system and method. The circuit protection device for an automobile includes: a protective metal oxide semiconductor field effect transistor (PROFET); and a controller connected to the PROFET; wherein the controller is configured to: receiving a feedback signal from a PROFET; and generating a control signal based on the feedback signal and sending the control signal to the PROFET, the control signal causing the PROFET to control a current of a load of the automotive circuit. The automobile circuit protection method comprises the following steps: receiving a feedback signal from a PROFET; and generating a control signal based on the feedback signal and sending the control signal to the PROFET, the control signal causing the PROFET to control current in the automotive circuit. The circuit protection system for an automobile includes: a receiving module configured to receive a feedback signal from a PROFET; a calculation module configured to generate a control signal based on the feedback signal, the control signal causing the PROFET to control a current of a load of the automotive circuit; and a transmit module configured to send a control signal to the PROFET.)

1. An automotive circuit protection device comprising:

a protective metal oxide semiconductor field effect transistor (PROFET); and

a controller connected to the PROFET;

wherein the controller is configured to:

receiving a feedback signal from the PROFET; and

generating a control signal based on the feedback signal and sending the control signal to the PROFET, the control signal causing the PROFET to control a current of a load of the automotive circuit.

2. The apparatus of claim 1, wherein the PROFET is configured to:

controlling a current of a load of the automotive circuit based on the first actual current flowing through the PROFET.

3. The apparatus of claim 1, wherein the controller is further configured to:

generating the control signal based on a second actual current derived from the feedback signal.

4. The apparatus of claim 1, wherein the controller is further configured to:

determining one or more of software protection parameters based on one or more of a PROFET parameter and a load current of the automotive circuit, wherein:

the PROFET parameters include a PROFET current inductance deviation range;

the load current comprises a surge current of the load and a rated steady-state current of the load; and

the software protection parameters comprise a software protection overcurrent threshold coefficient, a software protection overcurrent threshold and software protection starting time.

5. The apparatus of claim 4, wherein the controller is further configured to:

determining the software protection overcurrent threshold coefficient based on the PROFET current inductance deviation range; and

determining the software protection overcurrent threshold based on the software protection overcurrent threshold coefficient and a rated steady-state current of the load.

6. The apparatus of claim 4, wherein the controller is further configured to:

determining the software protection activation time based on a rush current of the load.

7. The apparatus of claim 1, wherein the controller is further configured to:

when the automobile circuit is controlled to be disconnected, counting the disconnection within preset time;

under the condition that the count in the preset time does not reach the preset times, the automobile circuit is conducted; and

and keeping the automobile circuit disconnected under the condition that the counting within the preset time reaches the preset times.

8. The apparatus of any of claims 1-7, wherein the PROFET is selected based on a rush current of a load of the automotive circuit.

9. The apparatus of any one of claims 1 to 7, wherein a conductor for a load of the automotive electrical circuit is determined based on one or more of the software protection parameters.

10. The apparatus of any of claims 1-7, wherein the PROFET and the load of the automotive circuit are connected in series between a power source and ground.

11. An automobile circuit protection method comprises the following steps:

receiving a feedback signal from a protection type metal oxide semiconductor field effect transistor (PROFET); and

generating a control signal based on the feedback signal and sending the control signal to the PROFET, the control signal causing the PROFET to control current in the automotive circuit.

12. The method of claim 11, further comprising the steps of:

controlling, by the PROFET, a current of a load of the automotive electrical circuit based on a first actual current flowing through the PROFET.

13. The method of claim 11, further comprising the steps of:

generating the control signal based on a second actual current derived from the feedback signal.

14. The method of claim 11, further comprising the steps of:

determining one or more of software protection parameters based on one or more of a PROFET parameter and a load current of the automotive circuit, wherein:

the PROFET parameters include a PROFET current inductance deviation range;

the load current comprises a surge current of the load and a rated steady-state current of the load; and

the software protection parameters comprise a software protection overcurrent threshold coefficient, a software protection overcurrent threshold and software protection starting time.

15. The method of claim 14, further comprising the steps of:

determining the software protection overcurrent threshold coefficient based on the PROFET current inductance deviation range; and

determining the software protection overcurrent threshold based on the software protection overcurrent threshold coefficient and a rated steady-state current of the load.

16. The method of claim 14, further comprising the steps of:

determining the software protection activation time based on a rush current of the load.

17. The method of claim 11, further comprising the steps of:

when the automobile circuit is controlled to be disconnected, counting the disconnection within preset time;

under the condition that the count in the preset time does not reach the preset times, the automobile circuit is conducted; and

and keeping the automobile circuit disconnected under the condition that the counting within the preset time reaches the preset times.

18. An automotive circuit protection system comprising:

a receiving module configured to receive a feedback signal from a protection type metal oxide semiconductor field effect transistor (PROFET);

a calculation module configured to generate a control signal based on the feedback signal, the control signal causing the PROFET to control a current of a load of the automotive circuit; and

a transmit module configured to send the control signal to the PROFET.

19. The system of claim 18, wherein the computing module is further configured to:

generating the control signal based on a second actual current derived from the feedback signal.

20. The system of claim 18, wherein the computing module is further configured to:

determining one or more of software protection parameters based on one or more of a PROFET parameter and a load current of the automotive circuit, wherein:

the PROFET parameters include a PROFET current inductance deviation range;

the load current comprises a surge current of the load and a rated steady-state current of the load; and

the software protection parameters comprise a software protection overcurrent threshold coefficient, a software protection overcurrent threshold and software protection starting time.

21. The system of claim 20, wherein the computing module is further configured to:

determining the software protection overcurrent threshold coefficient based on the PROFET current inductance deviation range; and

determining the software protection overcurrent threshold based on the software protection overcurrent threshold coefficient and a rated steady-state current of the load.

22. The system of claim 20, wherein the computing module is further configured to:

determining the software protection activation time based on a rush current of the load.

23. The system of claim 20, wherein the computing module is further configured to:

when the automobile circuit is controlled to be disconnected, counting the disconnection within preset time;

generating the control signal for conducting the automobile circuit under the condition that the count in the preset time does not reach a preset number of times; and

and generating the control signal for keeping the automobile circuit disconnected under the condition that the counting within the preset time reaches the preset times.

Technical Field

The invention relates to the field of automobile circuit protection. More particularly, the present invention relates to an automotive circuit protection device, system and method.

Background

In the existing vehicle type, relays and fuses are generally adopted for automobile load driving and circuit protection. Under the normal operating condition, the fuse can bear load current, and when the short circuit appears in the load circuit, the current that actually flows is greater than fuse rated current, and the fuse can fuse in a few seconds, cuts off the power supply, reaches the purpose of protection load and circuit wire. The fuse is selected according to load current, and the specification of the wire is selected according to rated current of the fuse, so that the current capacity of the wire capable of bearing the current is larger than the rated current of the fuse. Such an approach is limited by the specification grade of the fuse and the wire itself, and a certain degree of redundancy is formed, and the characteristics of the fuse itself lead to poor protection against resistive short circuit, and the fuse needs to be replaced after being blown.

Disclosure of Invention

Accordingly, there is a need for an automotive circuit protection device, system, and method that is lightweight, reliable, reduces wiring redundancy, and has a wide range of applicability.

To achieve one or more of the above objects, the present invention provides the following technical solutions.

According to a first aspect of the present invention, there is provided an automotive circuit protection device comprising: a protective metal oxide semiconductor field effect transistor (PROFET); and a controller connected to the PROFET; wherein the controller is configured to: receiving a feedback signal from the PROFET; and generating a control signal based on the feedback signal and sending the control signal to the PROFET, the control signal causing the PROFET to control a current of a load of the automotive circuit.

The apparatus according to an embodiment of the invention, wherein the PROFET is configured to: controlling a current of a load of the automotive circuit based on the first actual current flowing through the PROFET.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein the controller is further configured to: generating the control signal based on a second actual current derived from the feedback signal.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein the controller is further configured to: determining one or more of software protection parameters based on one or more of a PROFET parameter and a load current of the automotive circuit, wherein: the PROFET parameters include a PROFET current inductance deviation range; the load current comprises a surge current of the load and a rated steady-state current of the load; and the software protection parameters comprise a software protection overcurrent threshold coefficient, a software protection overcurrent threshold and software protection starting time.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein the controller is further configured to: determining the software protection overcurrent threshold coefficient based on the PROFET current inductance deviation range; and determining the software protection overcurrent threshold based on the software protection overcurrent threshold coefficient and a rated steady-state current of the load.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein the controller is further configured to: determining the software protection activation time based on a rush current of the load.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein the controller is further configured to: when the automobile circuit is controlled to be disconnected, counting the disconnection within preset time; under the condition that the count in the preset time does not reach the preset times, the automobile circuit is conducted; and keeping the automobile circuit disconnected under the condition that the counting within the preset time reaches the preset times.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein the PROFET is selected based on a rush current of a load of the automotive electrical circuit.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein a conductor for a load of the automotive electrical circuit is determined based on one or more of the software protection parameters.

An apparatus according to another embodiment of the invention or any of the embodiments above, wherein the PROFET and a load of the automotive circuit are connected in series between a power source and ground.

According to a second aspect of the present invention, there is provided a method for protecting an automotive circuit, comprising the steps of: receiving a feedback signal from a protection type metal oxide semiconductor field effect transistor (PROFET); and generating a control signal based on the feedback signal and sending the control signal to the PROFET, the control signal causing the PROFET to control current in the automotive circuit.

The method according to an embodiment of the present invention further comprises the steps of: controlling, by the PROFET, a current of a load of the automotive electrical circuit based on a first actual current flowing through the PROFET.

A method according to another embodiment of the invention or any of the embodiments above, further comprising the steps of: generating the control signal based on a second actual current derived from the feedback signal.

A method according to another embodiment of the invention or any of the embodiments above, further comprising the steps of: determining one or more of software protection parameters based on one or more of a PROFET parameter and a load current of the automotive circuit, wherein: the PROFET parameters include a PROFET current inductance deviation range; the load current comprises a surge current of the load and a rated steady-state current of the load; and the software protection parameters comprise a software protection overcurrent threshold coefficient, a software protection overcurrent threshold and software protection starting time.

A method according to another embodiment of the invention or any of the embodiments above, further comprising the steps of: determining the software protection overcurrent threshold coefficient based on the PROFET current inductance deviation range; and determining the software protection overcurrent threshold based on the software protection overcurrent threshold coefficient and a rated steady-state current of the load.

A method according to another embodiment of the invention or any of the embodiments above, further comprising the steps of: determining the software protection activation time based on a rush current of the load.

A method according to another embodiment of the invention or any of the embodiments above, further comprising the steps of: when the automobile circuit is controlled to be disconnected, counting the disconnection within preset time; under the condition that the count in the preset time does not reach the preset times, the automobile circuit is conducted; and keeping the automobile circuit disconnected under the condition that the counting within the preset time reaches the preset times.

According to a third aspect of the present invention, there is provided an automotive circuit protection system comprising: a receiving module configured to receive a feedback signal from a protection type metal oxide semiconductor field effect transistor (PROFET); a calculation module configured to generate a control signal based on the feedback signal, the control signal causing the PROFET to control a current of a load of the automotive circuit; and a transmit module configured to send the control signal to the PROFET.

The system according to an embodiment of the invention, wherein the computing module is further configured to: generating the control signal based on a second actual current derived from the feedback signal.

The system of another embodiment of the invention or any of the embodiments above, wherein the computing module is further configured to: determining one or more of software protection parameters based on one or more of a PROFET parameter and a load current of the automotive circuit, wherein: the PROFET parameters include a PROFET current inductance deviation range; the load current comprises a surge current of the load and a rated steady-state current of the load; and the software protection parameters comprise a software protection overcurrent threshold coefficient, a software protection overcurrent threshold and software protection starting time.

The system of another embodiment of the invention or any of the embodiments above, wherein the computing module is further configured to: determining the software protection overcurrent threshold coefficient based on the PROFET current inductance deviation range; and determining the software protection overcurrent threshold based on the software protection overcurrent threshold coefficient and a rated steady-state current of the load.

The system of another embodiment of the invention or any of the embodiments above, wherein the computing module is further configured to: determining the software protection activation time based on a rush current of the load.

The system of another embodiment of the invention or any of the embodiments above, wherein the computing module is further configured to: when the automobile circuit is controlled to be disconnected, counting the disconnection within preset time; generating the control signal for conducting the automobile circuit under the condition that the count in the preset time does not reach a preset number of times; and generating the control signal for keeping the automobile circuit disconnected under the condition that the counting in the preset time reaches the preset times.

The first aspect of the automotive circuit protection device, system and method according to the invention has the advantages that: the vehicle circuit is integrally protected by using a software and hardware protection strategy based on the PROFET, the traditional large-size heavy-weight relay and fuse are replaced, the short-circuit protection and diagnosis feedback current functions of the PROFET can be fully utilized, and the vehicle circuit has the characteristics of light weight and higher reliability.

The second aspect of the automotive circuit protection device, system and method according to the present invention has the advantages of: the introduction of a software protection strategy based on a PROFET enables the reduction of the line diameter. The software protection overcurrent threshold value directly sets a calculated protection required value according to the load current requirement and the software protection overcurrent threshold value coefficient (the coefficient is determined according to the current induction coefficient deviation range of the PROFET), can approach the load rated steady-state current under the condition of no false triggering, and can ensure that the long-time bearing capacity of the wire exceeds the load rated steady-state current and the short-time bearing capacity exceeds the software protection overcurrent threshold value when the wire specification is selected. The calculation and test prove that the wire has the effect of reducing the specification of the wire to a certain extent. The traditional mode is mostly to select the fuse according to load rated current earlier, and the wire that matches is selected according to fuse capacity again, because the specification grade of fuse and wire all is comparatively fixed and become the echelonment, and the cooperation is not good under some circumstances, leads to the electric current capacity redundancy of choosing the wire too big, and the line footpath can't reduce.

The third aspect of the automotive circuit protection device, system and method according to the present invention is advantageous in that: the software and hardware protection strategies are mutually matched, so that better, more accurate and wider-range circuit protection is achieved, and meanwhile, the flexibility is achieved. Through software protection, the output can be tried again when a temporary fault occurs, the normal working requirement of the load is maintained when the fault is recovered, and the circuit is cut off when the fault still exists, so that the purpose of protecting the circuit is achieved. On the other hand, the conventional method is limited by the specification grade of the fuse, and generally a minimum specification fuse larger than the value is required to be selected, and the generated difference can result in an increase of the protection starting value and a reduction of the protection range. The difference value can be eliminated through software protection, the protection range is enlarged, the protection starting time is more accurate and accurate, and overload and resistive short circuit protection is realized. For the huge current generated by direct short circuit, the circuit is cut off by means of hardware protection, the starting time is extremely short, and the damage to the load and the lead is reduced.

Drawings

The above and/or other aspects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the various aspects taken in conjunction with the accompanying drawings, in which like or similar elements are designated with like reference numerals. The drawings comprise:

fig. 1 is a schematic block diagram of an automotive circuit protection device 100 according to an embodiment of the present invention;

FIG. 2 is a schematic block diagram of a PROFET in accordance with one embodiment of the present invention;

FIG. 3 is a graph 200 of current flow in an automotive circuit according to an embodiment of the invention;

FIG. 4 is a schematic flow chart diagram of a method 300 for protecting automotive circuitry in accordance with one embodiment of the present invention; and

fig. 5 is a schematic flow chart diagram of the substeps of a method 300 for automotive circuit protection according to an embodiment of the present invention.

Detailed Description

In this specification, the invention is described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. The embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Words such as "comprising" and "comprises" mean that, in addition to having elements or steps which are directly and unequivocally stated in the description and the claims, the solution of the invention does not exclude other elements or steps which are not directly or unequivocally stated. Terms such as "first" and "second" do not denote an order of the elements in time, space, size, etc., but rather are used to distinguish one element from another.

The present invention is described below with reference to flowchart illustrations, block diagrams, and/or flow diagrams of methods and systems according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block and/or flow diagram block or blocks.

These computer program instructions may be loaded onto a computer or other programmable data processor to cause a series of operational steps to be performed on the computer or other programmable processor to produce a computer implemented process such that the instructions which execute on the computer or other programmable processor provide steps for implementing the functions or acts specified in the flowchart and/or block diagram block or blocks. It should also be noted that, in some alternative implementations, the functions/acts noted in the blocks may occur out of the order noted in the flowcharts. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

Where applicable, the various embodiments provided by the present disclosure may be implemented using hardware, software, or a combination of hardware and software. Additionally, where applicable, the various hardware components and/or software components set forth herein may be combined into composite components comprising software, hardware, and/or both without departing from the scope of the present disclosure. Where applicable, the various hardware components and/or software components set forth herein may be separated into sub-components comprising software, hardware, or both without departing from the scope of the present disclosure. Further, where applicable, it is contemplated that software components may be implemented as hardware components, and vice versa.

Referring now to fig. 1, fig. 1 is a schematic block diagram of an automotive circuit protection device 100 in accordance with an embodiment of the present invention. The automotive circuit protection device 100 may include a protective metal oxide semiconductor field effect transistor PROFET 101; and a controller 102 connected to the PROFET 101. In one embodiment, the automotive circuit protection device 100 may further include: the power supply 105, and the required number of PROFETs 101 and controllers 102, may be disposed in a fuse box 104, which fuse box 104 may be powered by the power supply 105. The PROFET 101 may be output controlled by the controller 102 to control the on and off of the MOSFETs (metal oxide semiconductor field effect transistors) in the PROFET 101 to further control the on and off of the circuit in which it is located. In one embodiment, the PROFET 101 and the load 103 of the automotive circuit are connected in series between the power supply 105 and ground. Typically, the PROFET 101 may be connected in the circuit as a high-side switch, in the order of power supply 105, PROFET 101, load 103, and ground overall. It is understood that PROFET 101 may be connected in any manner in a circuit so long as it is capable of functioning to control current in the circuit without departing from the scope of this disclosure. For clarity and simplicity, the apparatus and method of the present disclosure will be described hereinafter as an example of the connection of the PROFET 101 as a high-side switch (connected between the power supply and the load rather than between the load and ground).

In one aspect, the controller 102 may be configured to: receive a feedback signal from PROFET 101; and generating a control signal based on the feedback signal and sending a control signal to PROFET 101 that causes PROFET 101 to control the current of the load of the automotive circuit. The above operation of controlling and protecting the current of the automotive circuit by controlling the PROFET through the controller may be referred to as software protection. In one embodiment, the feedback signal from PROFET 101 may be a feedback current value that may be proportional or have a functional relationship to the actual current flowing through load 103 or PROFET 101, and thus controller 102 may be configured to generate and send a control signal to PROFET 101 based on a second actual current derived from the feedback signal. For example, under normal operating conditions, controller 102 turns on the MOSFETs in PROFET 101 according to user operation or other vehicle controller instructions, thereby causing current to flow through load 103 to power load 103. When the lead 106 is short-circuited, for example, resistively, or the load 103 is overloaded, for example, the controller 102 calculates a second actual current through a feedback signal (for example, a current sensing feedback current), and triggers the PROFET 101 to implement software protection after the second actual current exceeds a preset software protection overcurrent threshold for a preset software protection starting time, so as to disconnect the MOSFET, cut off the output, and protect the downstream circuit.

On the other hand, the PROFET 101 may be configured to control the current of the load of the automotive circuit based on the first actual current flowing through the PROFET, which operation may be referred to as hardware protection. PROFET 101 may generally have load diagnostic and protection capabilities, and in some cases, PROFET 101 may be used that is designed specifically for control of all load types including resistive, inductive, and capacitive loads in harsh automotive environments. These PROFETs have an extremely wide range of protection, such as overload, over-temperature, short circuit conditions in all types of automotive and industrial applications. In operation, under normal operating conditions, controller 102 turns on the MOSFETs in PROFET 101 in response to user operation or other vehicle controller commands, thereby causing current to flow through load 103 to power load 103. When a short circuit occurs in the wire 106, for example, to ground or the load 103, for example, an internal short circuit, and the first actual current flowing through the load 103 and the PROFET 101 exceeds the hardware protection current of the PROFET 101 itself, the PROFET 101 is triggered to perform short circuit hardware protection in a very short time, thereby turning off the MOSFET, cutting off the output, and protecting the downstream circuit. A schematic result diagram of the PROFET 101 can be seen in fig. 2. Here, in addition to the MOSFET circuit 1011 on the right side, there is an internal circuit 1012 of the PROFET 101. The internal circuit 1012 may convert the actual current in the MOSFET circuit 1011 into a feedback signal sent to the controller 102, and may also control the on and off of the MOSFET circuit 1011 based on a control signal from the controller 102.

In one embodiment, PROFET 101 may be selected based on the inrush current of a load of an automotive circuit. For example, when selecting a properly sized PROFET 101 for driving based on load current demand, the hardware protection current (i.e., its own current threshold) of the PROFET 101 must be greater than the inrush or inrush current of the load 103 to prevent a false disconnection of the load 103. Specifically, PROFET 101 can be selected to carry the rated steady state current I of load 103_steadyE.g. 150% or more. When a short circuit fault occurs, a hardware protection condition of the PROFET 101 is triggered to cause the PROFET 101 to perform hardware protection, shutting down the circuit. Wherein the current-time profile of the corresponding PROFET 101 is provided by the supplier of the PROFET 101.

In one embodiment, the controller may be further configured to: one or more of the software protection parameters are determined based on one or more of the PROFET parameters and the load current of the automotive circuit. Wherein: the PROFET parameters include a PROFET current inductance deviation range; the load current comprises the impact current of the load and the rated steady-state current of the load; and the software protection parameters comprise a software protection overcurrent threshold coefficient, a software protection overcurrent threshold and software protection starting time.

Specifically, in one embodiment, the controller may be configured to: determining a software protection overcurrent threshold coefficient based on the PROFET current inductance deviation range; and determining a software protection overcurrent based on the software protection overcurrent threshold coefficient and the rated steady-state current of the loadA flow threshold. For example, the range of deviation Δ k may be based on the selected current inductance of the PROFET 101_ILISTo determine the software protection over-current threshold coefficient k_pro. By way of example, if Δ k_ILISLess than 20% but not less than 14%, then k_proCan be taken as 1.5; if Δ k_ILISLess than 14%, then k_proMay be taken as 1.35. Then, according to the rated steady-state current I of the load 103_steadyCombined with the above-determined software protection overcurrent threshold coefficient k_proThe software protection overcurrent threshold I can be determined according to the following formula_pro：

I_pro=k_pro×I_steady。

In another embodiment, the controller may be further configured to: determining software protection start-up time t based on inrush current of load₁. For example, software protection start time t₁The appropriate value can be selected according to the sampling capability of the software, and should be greater than the duration of the load inrush current or inrush current to avoid false cut-off. Preferably, the software protection start-up time may be 380 ms. From this, a software protection current time curve may be determined, see in particular the current graph 200 shown in fig. 3.

Thus, when determining the software protection overcurrent threshold I_proAnd software protection start time t₁Thereafter, when the second actual current calculated by the controller 102 based on the current sense feedback current from the PROFET 101 exceeds the software protection overcurrent threshold I_proAnd continuously exceeds the software protection starting time t₁And then triggering software protection, disconnecting the MOSFET and cutting off the output so as to protect a downstream circuit.

Further, in addition to the above-described simple single on and off control of the circuit, the controller may be configured to execute the following automotive circuit protection method: when the automobile circuit is controlled to be disconnected, counting the disconnection within preset time; under the condition that the counting within the preset time does not reach the preset times, the automobile circuit is conducted; and keeping the automobile circuit disconnected under the condition that the counting within the preset time reaches the preset times.

In one embodiment, when no fault occurs, the controller 102 may control the conduction output of the MOSFET transistor according to a user operation or an instruction of another vehicle controller, so that the load 103 can operate normally. When a fault occurs, the controller 102 may be configured to: when a fault occurs and hardware or software protection is triggered, the circuit is cut off, an overcurrent flag bit is set, one is added to the overcurrent count or circuit disconnection count of the MOSFET, and a timer is started. Note that when the overcurrent flag is set, the controller 102 may be configured to control the MOSFET to not conduct an output.

Next, after a predetermined time (e.g., 3 s) has elapsed, if the overcurrent count or the circuit off count has not reached a predetermined number of times (e.g., 8 times), the overcurrent flag is cleared. At this point, the controller 102 may attempt to turn on the MOSFETs in the PROFET according to user operation or other vehicle controller instructions, since the over-current flag is cleared. In this process, the preset time is present in order to eliminate possible temporary faults in the circuit. The principle of the temporary fault removal is as follows: for example, if the vehicle has a temporary fault (e.g., momentary excessive current) for some reason and causes an overcurrent to open the circuit, then after a preset time has elapsed, the temporary fault (e.g., momentary excessive current) should not have existed, at which point if the controller 102 attempts to turn on using the MOSFETs in the PROFET, the circuit operation can be successfully restored without being again opened by the overcurrent. On the other hand, if a long-term fault that lasts for several minutes occurs and causes an overcurrent to open the circuit, the temporary fault still exists after a preset time has elapsed, at which point if the controller 102 attempts to turn on using the MOSFETs in the PROFET, the circuit operation cannot be successfully restored because the circuit will again open due to the overcurrent.

Specifically, in the event of a long-term fault in the circuit, after the circuit is first disconnected due to overcurrent, the overcurrent flag is set, the overcurrent count or circuit disconnection count of the MOSFET tube is incremented by one, and a timer is started, which counts a preset time of 3 seconds (in order to eliminate possible temporary faults). When the preset time of 3 seconds expires, the current count is 1 time and is not up to 8 times. At this point, the controller 102 may clear the flag bit (but not the flow count) and may attempt output based on user action or controller instructions. Because long-term faults occur, the circuit is disconnected due to overcurrent for the second time, the overcurrent flag bit is set at the moment, one is added to the overcurrent counting or circuit disconnection counting of the MOSFET, and the timer is started and counts the preset time for 3 seconds. When the preset time of 3 seconds expires, the current count is checked to be 2 times and not to reach 8 times. And circulating the steps until the counting reaches 8 times, keeping the over-current flag bit and prompting relevant information to a user. The controller 102 may control the MOSFET to not conduct an output until the fault is completely cleared, clearing the over-current count. The working operation of the load may then continue until a fault occurs triggering protection again. That is, if the controller 102 attempts to re-output successfully any time before the count reaches 8 times (24 seconds in this example), the circuit resumes operation, clearing the over-current count.

Optionally, the conductor 106 for the load of the automotive circuit may be determined based on one or more of the software protection parameters. For example, the 3000 hour current capacity (long time carrying capacity) of the conductor 106 may be greater than the rated steady state current I of the load 103_steady(ii) a The 1 hour current capacity (short time carrying capacity) of the conductor 106 may be greater than the software protection overcurrent threshold I_pro(ii) a The current-time profile of the selected gauge wire 106 may be higher than at least one of the software protection current-time profile and the PROFET current-time profile (see in particular the current graph 200 of fig. 3).

Turning now to fig. 4, fig. 4 is a schematic flow chart diagram of a method 300 for protecting a circuit of a vehicle according to an embodiment of the invention. In step 301, a feedback signal is received from a protection type metal oxide semiconductor field effect transistor (PROFET); in step 302, a control signal is generated based on the feedback signal and sent to the PROFET in step 303. Where the order of steps may be different, some steps may be performed in reverse order, concurrently, or in a loop. The automobile circuit protection method 300 according to an embodiment of the present invention further performs other steps corresponding to the operations performed by the apparatus according to the first aspect of the present invention, and will not be described herein again.

In the above method 300, the switching of the MOSFETs in the PROFET, i.e., the presence or absence of load current, may also be controlled according to the following sub-step 400.

Referring to fig. 5, sub-step 400 begins at block 401 and after starting turns on the MOSFETs in the PROFET (block 402). When the car circuit is controlled to be open (when judged yes at block 403), the opening is counted for a preset time (block 404). Turning on the car circuit (block 406) if the count within the preset time does not reach the preset number of times (no at block 405); and keeping the car circuit open (block 407) if the count within the preset time reaches a preset number of times (yes judgment at block 405). The substep 400 of the method 300 for protecting an automotive circuit according to an embodiment of the present invention further performs other steps corresponding to the operations performed by the apparatus according to the first aspect of the present invention in the implementation manner, which are not described herein again.

Software (such as program code and/or data) according to the present disclosure can be stored on one or more computer-readable media. It is also contemplated that the software identified herein may be implemented using one or more general purpose or special purpose computers and/or computer systems that are networked and/or otherwise. Where applicable, the order of various steps described herein can be changed, combined into composite steps, and/or separated into sub-steps to provide features described herein.

The foregoing disclosure is not intended to limit the disclosure to the precise forms or particular fields of use disclosed. Accordingly, it is contemplated that various alternative embodiments and/or modifications of the present disclosure, whether explicitly described or implied herein, are possible in light of the present disclosure. Having thus described embodiments of the present disclosure, it will be recognized by those of ordinary skill in the art that changes in form and detail may be made therein without departing from the scope of the present disclosure. Accordingly, the disclosure is limited only by the claims.