Intelligent power distribution box overcurrent protection circuit, intelligent power distribution box and vehicle
By designing an intelligent power distribution box overcurrent protection circuit, and combining hardware and software control, the problems of high cost and limited functionality of existing electronic fuse boxes are solved. This achieves low-cost overcurrent protection and delay processing, ensuring circuit safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JILIN ZHONG YING HIGH TECH CO LTD
- Filing Date
- 2025-06-24
- Publication Date
- 2026-07-07
AI Technical Summary
Existing electronic fuse boxes are expensive and have limited functionality, failing to effectively provide overcurrent protection and time delay.
An intelligent power distribution box overcurrent protection circuit was designed, including current detection, comparison, main control, time delay protection and drive control modules. Overcurrent delay protection is achieved by disconnecting the load power supply through hardware and combining it with software control.
It achieves low-cost overcurrent protection, which can quickly cut off the power supply to the load in case of overcurrent, and ensures accuracy through delayed judgment, thereby reducing the risk of fault expansion.
Smart Images
Figure CN224473043U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of automotive intelligent power distribution technology, and in particular to an overcurrent protection circuit for an intelligent power distribution box, an intelligent power distribution box, and a vehicle. Background Technology
[0002] Currently, in the automotive intelligent power distribution industry, electronic fuse boxes are used to replace traditional fuse boxes. Electronic fuse boxes need to predict and protect against over- and under-voltage events in the front-end power grid and high-voltage battery in advance to avoid damage to the back-end circuits and wiring harnesses. They also need to cut off the power supply in time when there is overcurrent or short circuit in the back-end circuit to prevent the fault from escalating further. In addition, they can determine the switching of the back-end power supply.
[0003] Current electronic fuse boxes primarily use high-side driver chips as a solution. These chips are divided into integrated chips and standalone driver chips. Integrated chips have built-in functions such as over / under voltage protection, overcurrent protection, overtemperature protection, on / off control, and fault feedback, but their cost is correspondingly higher. Standalone driver chips, on the other hand, have limited functionality, only controlling the switching state and lacking delay processing capabilities. Utility Model Content
[0004] This disclosure provides an overcurrent protection circuit for a smart power distribution box, a smart power distribution box, and a vehicle, to at least partially solve the above-mentioned problems.
[0005] This disclosure provides an overcurrent protection circuit for an intelligent power distribution box, including a vehicle-side power supply module, a current detection circuit, a comparison module, a main control module, a time-delay protection circuit, a drive control module, a switch module, and a load. The input terminal of the current detection circuit is connected to the output terminal of the vehicle-side power supply module. The output terminal of the current detection circuit is connected to the input terminal of the main control module and one input terminal of the comparison module. The other input terminal of the comparison module is connected to a first reference source. The output terminal of the comparison module is connected to the input terminal of the main control module and the input terminal of the drive control module. The output terminal of the main control module is connected to the input terminal of the drive control module via the time-delay protection circuit. The output terminal of the drive control module is connected to the input terminal of the switch module, and the output terminal of the switch module is connected to the load.
[0006] Preferably, the current detection circuit includes a current sampling resistor and an amplification module. The current sampling resistor is connected to the switching module, and the amplification module amplifies the voltage of the current sampling resistor and sends it to the main control module and the comparison module respectively.
[0007] Preferably, the comparison module includes a comparator, a first diode, and a first field-effect transistor. The non-inverting input of the comparator is connected to the output of the amplification module, the negative input of the comparator is connected to the first reference source, the output of the comparator is connected to the anode of the first diode, the connection point between the output of the comparator and the anode of the first diode is connected to the signal input of the main control module, the cathode of the first diode is connected to the gate of the first field-effect transistor, the drain of the first field-effect transistor is connected to the signal input of the drive control module, and the source of the first field-effect transistor is grounded.
[0008] Preferably, the comparison module further includes a second field-effect transistor, the gate of which is connected to the signal output terminal of the main control module, the drain of which is connected between the gate of the first field-effect transistor and the cathode of the first diode, and the source of which is grounded.
[0009] Preferably, the delay protection circuit includes an eleventh resistor, a ninth resistor, and a seventh capacitor. One end of the eleventh resistor is connected to the signal output terminal of the main control module, the other end of the eleventh resistor is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to one end of the seventh capacitor and the signal input terminal of the drive control module, and the other end of the seventh capacitor is grounded.
[0010] Another aspect of this disclosure provides an intelligent power distribution box, including the overcurrent protection circuit described in any of the above embodiments.
[0011] In another aspect, this disclosure provides a vehicle including the intelligent power distribution box described in the above embodiments.
[0012] According to the overcurrent protection circuit disclosed herein, the circuit structure is simple, the cost is low, and it has an overcurrent delay protection function. When an overcurrent occurs, the drive control module first disconnects the switch module in hardware to cut off the power supply to the load, and then the main control module takes over the control of the switch module. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic structural block diagram of the intelligent power distribution box overcurrent protection circuit according to a preferred embodiment of the present disclosure.
[0015] Figure 2This is a circuit diagram of a current detection circuit according to a preferred embodiment of the present disclosure.
[0016] Figure 3 The circuit diagram of the comparison module and its peripheral circuits is shown in the preferred embodiment of this disclosure.
[0017] Figure 4 The circuit diagram shows the delay protection circuit, drive control module and its peripheral circuits according to a preferred embodiment of this disclosure. Detailed Implementation
[0018] The preferred embodiments of this disclosure are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure. Furthermore, the embodiments and features in the embodiments of this disclosure can be combined with each other without conflict.
[0019] like Figure 1 As shown, this disclosure provides a preferred embodiment of an intelligent power distribution box overcurrent protection circuit, including a vehicle-side power supply module, a current detection circuit, a comparison module, a main control module, a time delay protection circuit, a drive control module, a switch module, and a load. The input terminal of the current detection circuit is connected to the output terminal of the vehicle-side power supply module, and the output terminal of the current detection circuit is connected to the input terminal of the main control module and one input terminal of the comparison module. The other input terminal of the comparison module is connected to a first reference source. The output terminal of the comparison module is connected to the input terminal of the main control module and the input terminal of the drive control module. The output terminal of the main control module is connected to the input terminal of the drive control module via the time delay protection circuit. The output terminal of the drive control module is connected to the input terminal of the switch module, and the output terminal of the switch module is connected to the load.
[0020] Specifically, such as Figure 2 As shown, the current detection circuit includes a current sampling resistor R1 and an amplification module U2. The current sampling resistor R1 is connected to the switching module, and the amplification module U2 amplifies the voltage of the current sampling resistor R1 and sends it to the main control module and the comparison module respectively.
[0021] Specifically, such as Figure 3 As shown, the comparison module includes a comparator U1B, a first diode D1, and a first field-effect transistor Q3. The non-inverting input of the comparator U1B is connected to the output of the amplification module U2, the negative input of the comparator U1B is connected to the first reference source, the output of the comparator U1B is connected to the anode of the first diode D1, the connection point between the output of the comparator U1B and the anode of the first diode D1 is connected to the signal input of the main control module, the cathode of the first diode D1 is connected to the gate of the first field-effect transistor Q3, the drain of the first field-effect transistor Q3 is connected to the signal input of the drive control module, and the source of the first field-effect transistor Q3 is grounded.
[0022] More specifically, such as Figure 3 As shown, the comparison module also includes a second field-effect transistor Q6. The gate of the second field-effect transistor Q6 is connected to the signal output terminal of the main control module, the drain of the second field-effect transistor Q6 is connected between the gate of the first field-effect transistor Q3 and the cathode of the first diode D1, and the source of the second field-effect transistor Q6 is grounded.
[0023] Specifically, such as Figure 4 As shown, the delay protection circuit includes an eleventh resistor R11, a ninth resistor R9, and a seventh capacitor C7. One end of the eleventh resistor R11 is connected to the signal output terminal of the main control module, and the other end of the eleventh resistor R11 is connected to one end of the ninth resistor R9. The other end of the ninth resistor R9 is connected to one end of the seventh capacitor C7 and the signal input terminal of the drive control module, respectively. The other end of the seventh capacitor C7 is grounded.
[0024] Next, in conjunction with the appendix Figures 1 to 4 The working principle of the overcurrent protection circuit is explained in detail.
[0025] The main control module (which can be understood as a microcontroller MCU) controls the drive module, namely the high-side drive chip U3, through the high and low level signals (MCU-HSD-SW1-X4-EN). The high-side drive chip U3 itself generates charge pump output control signals (LOAD4_GA, X4_VS) to control the switching module, that is, the conduction or shutdown of MOSFETs (Q1, Q2, Q4, Q5).
[0026] When the MOSFETs (Q1, Q2, Q4, Q5) are turned on, the current of the power supply VBAT flows through the MOSFETs (Q1, Q2, Q4, Q5) and the current sampling resistor R1, and is output to OUT_4 to supply power to each load.
[0027] When current flows through the circuit, the voltage across the current sampling resistor R1 increases proportionally and enters the amplification module U2 from node X4_DS1 and node X4_DS. After being amplified by the amplification module U2, the current parameters are obtained from the MCU through MCU_I_4_H, and at the same time, they enter the comparator U1B through I_4_H.
[0028] When an overcurrent occurs, the voltage across the current sampling resistor R1 increases. This voltage is compared by comparator U1B, and if the current exceeds a set threshold, comparator U1B outputs a high level. After comparator U1B outputs a high level, the overcurrent signal MCU_I_4_OCP is sent to the MCU. This signal, via the first diode D1, controls the first field-effect transistor Q3. When the gate of the first field-effect transistor Q3 goes high, Q3 turns on, pulling the drive signal X4_IN of the high-side driver chip U3 low, thus turning off the MOSFET and stopping the overcurrent.
[0029] The above process is the first hardware disconnection process executed when an overcurrent occurs. After the MOSFET is disconnected due to the overcurrent, the overcurrent signal disappears, the comparator U1B outputs a low level, the first field-effect transistor Q3 is disconnected, and the drive signal X4-IN of the high-side driver chip U3 is pulled high. However, due to the presence of the seventh capacitor C7, it plays the role of delaying the MOSFET's turn-on. During this delay period, the MCU detects the real-time current value through MCU_I_4_H and determines that an overcurrent has indeed occurred. Then, the MCU takes over the subsequent software control process of the MOSFET.
[0030] In addition, after receiving the overcurrent signal MCU_I_4_OCP, the MCU can control the second field-effect transistor Q6 through the signal MCU_I_4_CLOS_OCP. Specifically, if the MCU determines that the current exceeds the threshold due to a spike interference based on the overcurrent signal MCU_I_4_OCP, it controls the second field-effect transistor Q6 to close, thereby turning off the hardware overcurrent protection.
[0031] Another aspect of this disclosure provides an intelligent power distribution box, including the overcurrent protection circuit described in any of the above embodiments.
[0032] In another aspect, this disclosure provides a vehicle including the aforementioned smart power distribution box.
[0033] The overcurrent protection circuit disclosed herein has an overcurrent delay protection function. When an overcurrent occurs, the switch module is first disconnected by the drive control module to cut off the power supply to the load, and then the main control module takes over the control of the switch module.
[0034] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.
[0035] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this disclosure without departing from the spirit and scope of the embodiments of this disclosure. Therefore, if these modifications and variations to the embodiments of this disclosure fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include these modifications and variations.
[0036] It should also be understood that, in the embodiments herein, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following associated objects have an "or" relationship.
[0037] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this document.
[0038] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.
[0039] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments described herein, depending on actual needs.
[0040] Furthermore, the functional units in the various embodiments of this document can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.
[0041] This document uses specific embodiments to illustrate the principles and implementation methods of this document. The descriptions of the embodiments above are only for the purpose of helping to understand the methods and core ideas of this document. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this document. Therefore, the content of this specification should not be construed as a limitation of this document.
Claims
1. An overcurrent protection circuit for an intelligent power distribution box, characterized in that, The system includes a vehicle-side power supply module, a current detection circuit, a comparison module, a main control module, a time delay protection circuit, a drive control module, a switch module, and a load. The input of the current detection circuit is connected to the output of the vehicle-side power supply module. The output of the current detection circuit is connected to the input of the main control module and one input of the comparison module. The other input of the comparison module is connected to a first reference source. The output of the comparison module is connected to the input of the main control module and the input of the drive control module. The output of the main control module is connected to the input of the drive control module via the time delay protection circuit. The output of the drive control module is connected to the input of the switch module. The output of the switch module is connected to the load.
2. The intelligent power distribution box overcurrent protection circuit according to claim 1, characterized in that, The current detection circuit includes a current sampling resistor and an amplification module. The current sampling resistor is connected to the switching module. The amplification module amplifies the voltage of the current sampling resistor and sends it to the main control module and the comparison module respectively.
3. The intelligent power distribution box overcurrent protection circuit according to claim 2, characterized in that, The comparison module includes a comparator, a first diode, and a first field-effect transistor. The non-inverting input of the comparator is connected to the output of the amplification module, the negative input of the comparator is connected to the first reference source, the output of the comparator is connected to the anode of the first diode, the connection point between the output of the comparator and the anode of the first diode is connected to the signal input of the main control module, the cathode of the first diode is connected to the gate of the first field-effect transistor, the drain of the first field-effect transistor is connected to the signal input of the drive control module, and the source of the first field-effect transistor is grounded.
4. The intelligent power distribution box overcurrent protection circuit according to claim 3, characterized in that, The comparison module further includes a second field-effect transistor (FET), the gate of which is connected to the signal output terminal of the main control module, the drain of which is connected between the gate of the first FET and the cathode of the first diode, and the source of which is grounded.
5. The intelligent power distribution box overcurrent protection circuit according to claim 1, characterized in that, The delay protection circuit includes an eleventh resistor, a ninth resistor, and a seventh capacitor. One end of the eleventh resistor is connected to the signal output terminal of the main control module, and the other end of the eleventh resistor is connected to one end of the ninth resistor. The other end of the ninth resistor is connected to one end of the seventh capacitor and the signal input terminal of the drive control module, respectively. The other end of the seventh capacitor is grounded.
6. A smart power distribution box, characterized in that, Includes the overcurrent protection circuit according to any one of claims 1 to 5.
7. A vehicle, characterized in that, Includes the intelligent power distribution box according to claim 6.