Current detection control circuit and distribution box
By designing a current detection control circuit in the intelligent distribution box, using a normal power detection module and a power distribution detection module, the accurate detection of normal power and distribution current is achieved, and the problem of insufficient sensitivity and sampling accuracy in the existing technology is solved, and the demand for a wide range of current loads is met.
Patent Information
- Application Number
- CN202422095398.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-08-28
AI Technical Summary
When existing smart distribution boxes detect normal current and distribution current, their sensitivity and sampling accuracy are difficult to meet high requirements, especially in the large current range.
A current detection control circuit is designed, including a normal power detection module and a power distribution detection module. Through the distribution sampling resistor, a large current drive control chip and a small current drive control chip, combined with the control module, the accurate detection of normal power and distribution current is achieved.
It realizes accurate monitoring of normal current and distribution current, meets a wide range of current load requirements, ensures the overcurrent capability of large currents, and improves the sampling accuracy of small currents.
Smart Images
Figure CN222933853U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automotive intelligent distribution boxes, in particular to a current detection control circuit and a distribution box. Background Art
[0002] As the primary power distribution management unit of a vehicle, an intelligent distribution box controls the turning on and off of all power sources in the vehicle. Therefore, it is necessary to monitor the power consumption parameters of in-vehicle devices in real time to ensure vehicle safety. The current consumption of the intelligent distribution box is roughly divided into constant power current consumption and distribution current consumption. The constant power current consumption includes, for example, the consumption of the MCU (Microcontroller Unit), SBC (System Basis Chip) power management circuit, and peripheral circuits. The current consumed by these constant power modules is usually very small, with a minimum of several milliamperes. Therefore, detecting the constant power current consumption requires high sensitivity. The distribution current consumption refers to the consumption of the load circuit controlled by the MCU. Due to different loads, the distribution current consumption has a large range, but high sampling accuracy is still required within the large current range. Therefore, accurately detecting small and large currents of devices has become an important technical indicator. Summary of the Utility Model
[0003] Embodiments of the present disclosure provide a current detection control circuit to at least partially solve the problem of accurate current monitoring.
[0004] On the one hand, the present disclosure provides a current detection control circuit for detecting the current on the constant power loop between the power supply and the load and on the distribution loop of the distribution box. The current detection control circuit includes at least one constant power detection module, at least one distribution detection module, and a control module. The input end of the constant power detection module is connected to the power supply, and the output end of the constant power detection module is connected to the input end of the control module. The distribution detection module includes a distribution sampling resistor, a large current drive control chip, and a small current drive control chip. The distribution sampling resistor is connected into the distribution loop. The input ends of the large current drive control chip and the small current drive control chip are both connected to both ends of the distribution sampling resistor. The output ends of the large current drive control chip and the small current drive control chip are both connected to the input end of the control module.
[0005] Preferably, the control module is configured to: when it is determined that the voltage value output by the small current drive control chip is greater than a preset threshold, calculate the current on the distribution loop according to the voltage value detected by the large current drive control chip; when it is determined that the voltage value output by the small current drive control chip is less than the preset threshold, calculate the current on the distribution loop according to the voltage value detected by the small current drive control chip.
[0006] Preferably, the control module is configured to calculate the current on the constant power supply circuit according to the voltage value output by the constant power supply detection module.
[0007] Preferably, at least one of the power distribution detection modules includes a main power distribution detection module disposed on the main circuit of the power distribution circuit and / or each branch power distribution detection module disposed on each branch circuit of the power distribution circuit.
[0008] Preferably, a first MOS transistor is further included. The first MOS transistor is connected in series on the main circuit of the power distribution circuit before the load. The control module is electrically connected to the gate of the first MOS transistor and is configured to control the conduction and cutoff of the first MOS transistor according to the current on the main circuit calculated based on the voltage value detected by the main power distribution detection module.
[0009] Preferably, there are multiple loads, and a second MOS transistor is disposed on each branch circuit of each power distribution circuit where each load is located. The control module is electrically connected to the gate of the second MOS transistor and is configured to control the conduction and cutoff of each second MOS transistor according to the current on each branch circuit calculated based on the voltage value detected by each branch power distribution detection module.
[0010] Preferably, the resistance value of the power distribution sampling resistor in each branch power distribution detection module is 0.1 mΩ - 3 Ω.
[0011] Preferably, the constant power supply detection module includes a constant power supply sampling resistor, a reference voltage source, and a first operational amplifier. The constant power supply sampling resistor is connected into the constant power supply circuit. The input end of the operational amplifier is connected to both ends of the constant power supply sampling resistor. The reference voltage source is connected to the reference voltage input end of the first operational amplifier. The output end of the first operational amplifier is connected to the input end of the control module.
[0012] Preferably, the constant power supply detection module further includes an anti-reverse connection circuit and a filtering circuit. The output end of the power supply is connected to the constant power supply sampling resistor through the anti-reverse connection circuit and the filtering circuit in sequence.
[0013] On the other hand, the present disclosure provides a power distribution box, including:
[0014] A box body;
[0015] A circuit board installed in the box body; and
[0016] The current detection and control circuit according to any one of the above embodiments, integrated on the circuit board.
[0017] According to the current detection control circuit of the present disclosure, both the constant power supply current and the power distribution current can be accurately monitored; and during the monitoring of the power distribution current, it can meet the current load requirements in a wide range, ensuring both the overcurrent capacity for large currents and improving the sampling accuracy for small currents. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.
[0019] Figure 1 It is a block diagram of the current detection control circuit of the preferred embodiment in this article.
[0020] Figure 2 It is a circuit schematic diagram of the constant power supply detection module of the preferred embodiment in this article.
[0021] Figure 3 It is a combined schematic diagram of the circuit principle of the power distribution detection module of the preferred embodiment in this article. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] The following describes the preferred embodiments of the present disclosure in conjunction with the drawings of the specification. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure. And without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other.
[0023] As Figure 1 shown, it is a block diagram of the current detection control circuit of a preferred embodiment of the present disclosure. The current detection control circuit is used to detect the current on the constant power supply loop of the distribution box and on the power distribution loop between the power supply (which can be a battery or DCDC power supply) and the load. The current detection control circuit includes at least one constant power supply detection module 10, at least one power distribution detection module, and a control module. The input end of the constant power supply detection module 10 is connected to the power supply, and the output end of the constant power supply detection module 10 is connected to the input end of the control module; the power distribution detection module includes a power distribution sampling resistor, a large current drive control chip U101, and a small current drive control chip U8. The power distribution sampling resistor is connected into the power distribution loop. The input ends of the large current drive control chip U101 and the small current drive control chip U8 are both connected to both ends of the power distribution sampling resistor, and the output ends of the large current drive control chip U101 and the small current drive control chip U8 are both connected to the input end of the control module.
[0024] Thus, by setting up the constant power supply detection module 10 and the power distribution detection module, the real-time detection of the constant power supply current and the power distribution current is achieved simultaneously; by setting up the high-current drive control chip U101 and the low-current drive control chip U8 in the power distribution detection module, the current load requirements in a wide range are met, which not only ensures the overcurrent capacity of the high current but also improves the sampling accuracy of the low current, and at the same time simplifies the circuit structure design in the intelligent power distribution box.
[0025] Specifically, in some embodiments, the constant power supply detection module 10 includes a constant power supply sampling resistor, a reference voltage source, and a first operational amplifier. The constant power supply sampling resistor is connected to the constant power supply circuit. The input terminals of the operational amplifier are connected to both ends of the constant power supply sampling resistor. The reference voltage source is connected to the reference voltage input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the input terminal of the control module.
[0026] Furthermore, the constant power supply detection module 10 further includes an anti-reverse connection circuit and a filtering circuit. The output terminal of the power supply is sequentially connected to the constant power supply sampling resistor through the anti-reverse connection circuit and the filtering circuit.
[0027] In this embodiment, as Figure 2 shown, two ways of power supply to this current detection and control circuit are shown, namely, the battery powers this current detection and control circuit and the DCDC DC power supply powers this current detection and control circuit. For the battery power supply method, the anti-reverse connection circuit includes the first diode D1, and the battery voltage enters the subsequent filtering circuit through the first diode D1; for the DCDC DC power supply method, the anti-reverse connection circuit includes the ninth diode D9, and the DCDC voltage enters the subsequent filtering circuit through the ninth diode D9. The filtering circuit is composed of the first capacitor C1, the third diode D3, the third inductor L3, the second capacitor C2, the third capacitor C3, the first inductor L1, the fourth capacitor C4, the sixth capacitor C6, the seventh capacitor C7, the first three-one capacitor C131, and the first three-zero capacitor C130 as Figure 2 shown. That is, after the power supply voltage is filtered, it supplies power to the control module (which can be understood as the MCU), the SBC (System Basic Chip), and the peripheral circuits through the constant power supply sampling resistor R1. Both ends of the constant power supply sampling resistor R1 are connected to the first operational amplifier U2. The reference voltage source U1 provides a reference voltage for the first operational amplifier U2. The voltage divided by the constant power supply sampling resistor R1 is amplified by the first operational amplifier U2 and led out from the eighth pin U8, and then input to the MCU through the second resistor R2 and the tenth capacitor C10. Thus, the MCU can calculate the current on the constant power supply circuit according to the voltage value output by the constant power supply detection module 10. As can be seen from the above description, the current value on the constant power supply circuit = the fixed loss value of the pre-stage filtering circuit + the detection value of the constant power supply sampling resistor R1, where the fixed loss value of the pre-stage filtering circuit can be obtained by pre-testing with a power meter.
[0028] Next, in combination withFigure 1 and Figure 3 Explain the principle of the circuit for detecting the current in the power distribution loop between the power supply and the load.
[0029] The current in the power distribution loop is the load current when powered on controlled by the MCU. The loads applied in new energy vehicles usually include motors, electronic parking brakes, lights, seats, etc. Therefore, the current change range in the power distribution loop is wide, usually in the range of 0 - 300A.
[0030] Specifically, at least one power distribution detection module may include a main power distribution detection module 20 disposed on the main circuit in the power distribution loop and / or each branch power distribution detection module 40 disposed on each branch circuit in the power distribution loop.
[0031] In this embodiment, as Figure 1 shown, the main power distribution detection module 20 and the branch power distribution detection module on the branch circuit with the motor as the load are shown. In addition, the branch power distribution detection modules on several other branch circuits are not shown. Both the main power distribution detection module 20 and the branch power distribution detection module include a power distribution sampling resistor, a large - current drive control chip U101, and a small - current drive control chip U8. The difference is only that the resistance values of the power distribution sampling resistors on the main circuit and each branch circuit are selected one by one according to the total power consumption of the load and the power consumption of each branch load.
[0032] Now, taking the main power distribution module as an example for explanation, as Figure 3 shown, the power distribution sampling resistors R128 and R129 are connected in parallel. The sixteenth and seventeenth pins of the large - current drive control chip U101 are connected to both ends of the parallel - connected power distribution sampling resistors R128 and R129. After the battery voltage or the DCDC DC power supply voltage is input to the large - current drive control chip U101 through the power distribution sampling resistors R128 and R129 for operational amplification processing, the first pin CSO1 of the large - current drive control chip U101 outputs a voltage signal to the MCU; similarly, the second pin IN+ and the third pin IN - of the small - current drive control chip U8 are connected to both ends of the parallel - connected power distribution sampling resistors R128 and R129. After the battery voltage or the DCDC DC power supply voltage is input to the small - current drive control chip U8 through the power distribution sampling resistors R128 and R129 for operational processing, the eighth pin OUT of the small - current drive control chip U8 outputs a voltage signal to the MCU.
[0033] It can be understood that for the high - current drive control chip U101, a chip with higher detection accuracy in the high - current range (usually 10 - 300A) needs to be selected, and for the low - current drive control chip U8, a chip with higher detection accuracy in the low - current range (usually 0 - 10A) needs to be selected. The high - current drive control chip U101 and the low - current drive control chip U8 simultaneously collect the current on the main circuit in the power distribution loop and transmit it to the MCU. The MCU is configured as follows: when it is determined that the voltage value output by the low - current drive control chip U8 is greater than the preset threshold, calculate the current on the power distribution loop according to the voltage value detected by the high - current drive control chip U101; when it is determined that the voltage value output by the low - current drive control chip U8 is less than the preset threshold, calculate the current on the power distribution loop according to the voltage value detected by the low - current drive control chip U8.
[0034] It should be noted that the preset threshold is determined based on the detection accuracy characteristics of the high - current drive control chip U101 and the low - current drive control chip U8. The value of the preset threshold needs to ensure that the current detection accuracy of the low - current drive control chip U8 can reach within 1% and above, and the current detection accuracy of the high - current drive control chip U101 can also reach 1% and above. In this way, the current detection accuracy in the entire current detection range is 1% and above. When the high - current drive control chip U101 performs low - current detection, the detection accuracy is extremely low or basically unable to detect. The low - current drive control chip U8 has high accuracy when performing low - current detection and low accuracy when performing high - current detection. However, although the accuracy is low when performing high - current detection, it can still reach more than 5%. Therefore, the voltage value detected by the low - current drive control chip U8 is compared with the preset threshold.
[0035] In some embodiments, as Figure 1 shown, the circuit may further include a first MOS transistor 301. The first MOS transistor 301 is connected in series on the main circuit in the power distribution loop before the load. The control module is electrically connected to the gate of the first MOS transistor 301 and is used to control the conduction and cut - off of the first MOS transistor 301 according to the current on the main circuit calculated from the voltage value detected by the main power distribution detection module 20.
[0036] Thus, the MCU can control the conduction and cut - off of the first MOS transistor 301 according to the current value on the main circuit in the power distribution loop, directly ensuring the normal operation of all loads as a whole.
[0037] Furthermore, in some embodiments, as Figure 1As shown, there can be multiple loads, such as motors, lights, seats, etc. Second MOS transistors 302 can be provided on each branch circuit of the power distribution circuit where each load is located. The control module is electrically connected to the gates of the second MOS transistors 302 and is used to control the conduction and cutoff of each second MOS transistor 302 according to the current on each branch circuit calculated based on the voltage values detected by each branch power distribution detection module. Thus, when an abnormality occurs in a certain branch circuit, the operation of the load on that branch can be directly turned off.
[0038] In this embodiment, the resistance value of the power distribution sampling resistor in each branch power distribution detection module is 0.1 mΩ - 3 Ω. The specific resistance value can be set according to actual requirements, and no specific limitation is made herein.
[0039] Although the preferred embodiments of the present disclosure have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present disclosure.
[0040] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present disclosure without departing from the spirit and scope of the embodiments of the present disclosure. Thus, if these modifications and variations of the embodiments of the present disclosure fall within the scope of the claims of the present disclosure and their equivalent technologies, the present disclosure also intends to include these modifications and variations.
[0041] It should also be understood that in the embodiments herein, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.
[0042] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this article.
[0043] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.
[0044] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or may be distributed over multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments in this article.
[0045] In addition, each functional unit in the various embodiments in this article may be integrated in a processing unit, may exist separately as individual physical units, or two or more units may be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.
[0046] Specific embodiments are used in this article to elaborate on the principles and implementation manners of this article. The description of the above embodiments is only used to help understand the method and its core idea in this article; at the same time, for those of ordinary skill in the art, according to the idea in this article, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to this article.
Claims
1. A current detection control circuit, characterized in that: Used to detect the current on the normal power circuit of the distribution box and the distribution circuit between the power supply and the load, the current detection control circuit includes at least one normal power detection module, at least one distribution detection module and a control module, the input end of the normal power detection module is connected to the power supply, and the output end of the normal power detection module is connected to the input end of the control module; the distribution detection module includes a distribution sampling resistor, a large current drive control chip and a small current drive control chip, the distribution sampling resistor is connected to the distribution circuit, the input end of the large current drive control chip and the input end of the small current drive control chip are both connected to the two ends of the distribution sampling resistor, and the output end of the large current drive control chip and the output end of the small current drive control chip are both connected to the input end of the control module.
2. The current detection control circuit according to claim 1, characterized in that: The control module is configured to: when it is determined that the voltage value output by the small current drive control chip is greater than a preset threshold, calculate the current on the power distribution circuit according to the voltage value detected by the large current drive control chip; When it is determined that the voltage value output by the small current drive control chip is less than the preset threshold value, the current on the power distribution circuit is calculated according to the voltage value detected by the small current drive control chip.
3. The current detection control circuit according to claim 1, characterized in that: The control module is configured to calculate the current on the normal power circuit according to the voltage value output by the normal power detection module.
4. The current detection control circuit according to claim 1, characterized in that: At least one of the power distribution detection modules includes a main power distribution detection module arranged on a main circuit in the power distribution circuit and / or each branch power distribution detection module arranged on each branch circuit in the power distribution circuit.
5. The current detection control circuit according to claim 4, characterized in that: It also includes a first MOS tube, which is connected in series on the main circuit in the power distribution circuit before the load. The control module is electrically connected to the gate of the first MOS tube and is used to control the conduction and cutoff of the first MOS tube according to the current on the main circuit calculated according to the voltage value detected by the main power distribution detection module.
6. The current detection control circuit according to claim 5, characterized in that: There are multiple loads, and each branch circuit of the power distribution circuit where each load is located is provided with a second MOS tube. The control module is electrically connected to the gate of the second MOS tube, and is used to control the conduction and cutoff of each second MOS tube according to the current on each branch circuit calculated according to the voltage value detected by each branch power distribution detection module.
7. The current detection control circuit according to claim 4, characterized in that: The resistance of the distribution sampling resistor in each of the branch power distribution detection modules is 0.1 mΩ-3Ω.
8. The current detection control circuit according to claim 1, characterized in that: The normal power detection module includes a normal power sampling resistor, a reference voltage source and a first operational amplifier. The normal power sampling resistor is connected to the normal power circuit, the input end of the operational amplifier is connected to the two ends of the normal power sampling resistor, the reference voltage source is connected to the reference voltage input end of the first operational amplifier, and the output end of the first operational amplifier is connected to the input end of the control module.
9. The current detection control circuit according to claim 8, characterized in that: The normal power detection module further includes an anti-reverse connection circuit and a filter circuit, and the output end of the power supply is connected to the normal power sampling resistor through the anti-reverse connection circuit and the filter circuit in sequence.
10. A distribution box, characterized in that: include: Box body; A circuit board is installed in the box body; as well as The current detection control circuit according to any one of claims 1 to 9 is integrated on the circuit board.