A high-voltage acquisition circuit

Abstract

The application provides a high-voltage acquisition circuit, which comprises an electrostatic protection circuit, a switch control circuit, a voltage division circuit, a secondary filter circuit and a microcontroller; the switch control circuit is connected with the output end of the electrostatic protection circuit, the input end of the secondary filter circuit and the microcontroller respectively; the input end of the electrostatic protection circuit is connected with a power supply; the output end of the secondary filter circuit is connected with the microcontroller; and the voltage division circuit is connected between the switch control circuit and the secondary filter circuit. The electrostatic protection circuit solves the problem that the ordinary electrostatic capacitor has low voltage resistance and is broken down by the battery pack voltage, and the secondary filter circuit improves the anti-interference performance of the acquired voltage signal, so that the high-voltage battery voltage is safely and stably monitored.

Description

Technical Field

[0001] This application relates to the field of battery management technology, and in particular to a high-voltage acquisition circuit. Background Technology

[0002] With the development of new energy vehicles, the requirements for high-voltage battery performance monitoring parameters are becoming increasingly stringent. The battery management system is responsible for collecting and uploading parameters such as voltage, temperature, and insulation detection of the positive and negative terminals of the battery. The existing solution is to use ordinary low-voltage capacitors or high-voltage capacitors for electrostatic protection at the power acquisition port and to perform capacitor filtering at the acquisition port.

[0003] However, as battery voltage levels increase, ordinary electrostatic capacitors are short-circuited by the high voltage of the battery pack itself, and their withstand voltage cannot meet the requirements. At the same time, high-voltage capacitors are more expensive. Utility Model Content

[0004] In view of this, this application provides a high-voltage acquisition circuit for safe and stable monitoring of high-voltage battery voltage.

[0005] This application provides an electro-hydraulic control device, comprising:

[0006] Electrostatic protection circuit, switch control circuit, voltage divider circuit, two-stage filter circuit, and microcontroller;

[0007] The switch control circuit is connected to the output terminal of the electrostatic protection circuit, the input terminal of the secondary filter circuit, and the microcontroller, respectively; the input terminal of the electrostatic protection circuit is connected to the power supply; the output terminal of the secondary filter circuit is connected to the microcontroller; and the voltage divider circuit is connected between the switch control circuit and the secondary filter circuit.

[0008] Optionally, the electrostatic discharge protection circuit includes:

[0009] First resistor, second resistor, and third resistor;

[0010] The first resistor is connected to the second resistor and the power supply respectively; the third resistor is connected to the second resistor and the switch control circuit respectively.

[0011] Optionally, the voltage divider circuit includes:

[0012] Fourth resistor;

[0013] One end of the fourth resistor is grounded, and the other end is connected between the switch control circuit and the secondary filter circuit.

[0014] Optionally, the secondary filter circuit includes:

[0015] First filter circuit and second filter circuit;

[0016] The first filter circuit is connected to the output terminal of the switch control circuit and the input terminal of the second filter circuit, respectively; the output terminal of the second filter circuit is connected to the microcontroller.

[0017] Optionally, the first filtering circuit includes:

[0018] Ferrite bead and first capacitor;

[0019] The magnetic beads are respectively connected to the output terminal of the switch control circuit and the input terminal of the second filter circuit;

[0020] One end of the first capacitor is grounded, and the other end is connected between the ferrite bead and the input terminal of the second filter circuit.

[0021] Optionally, the second filter circuit includes:

[0022] The fifth resistor and the second capacitor;

[0023] The fifth resistor is connected to the first filter circuit and the microcontroller, respectively.

[0024] One end of the second capacitor is grounded, and the other end is connected between the fifth resistor and the microcontroller.

[0025] Optionally, the switch control circuit includes:

[0026] N-type metal-oxide-semiconductor field-effect transistor, sixth resistor and seventh resistor;

[0027] The N-type metal-oxide-semiconductor field-effect transistor is connected to the output terminal of the electrostatic protection circuit, the input terminal of the secondary filter circuit, and one end of the seventh resistor; the other end of the seventh resistor is connected to the microcontroller.

[0028] One end of the sixth resistor is grounded, and the other end is connected between the N-type metal-oxide-semiconductor field-effect transistor and the seventh resistor.

[0029] Optionally, the power source is a battery pack; one end of the battery pack is grounded, and the other end is connected to the input terminal of the electrostatic protection circuit.

[0030] Optionally, the microcontroller includes:

[0031] Control signal pins and analog input pins;

[0032] The switch control circuit is connected to the output terminal of the electrostatic protection circuit, the input terminal of the secondary filter circuit, and the control signal pin, respectively.

[0033] The output terminal of the secondary filter circuit is connected to the analog input pin.

[0034] Optionally, the first resistor, the second resistor, and the third resistor are in megaohm-class large packages.

[0035] As can be seen from the above scheme, this application provides a high-voltage acquisition circuit, which includes an electrostatic discharge (ESD) protection circuit, a switch control circuit, a voltage divider circuit, a two-stage filter circuit, and a microcontroller. The switch control circuit is connected to the output terminal of the ESD protection circuit, the input terminal of the two-stage filter circuit, and the microcontroller, respectively. The input terminal of the ESD protection circuit is connected to a power supply. The output terminal of the two-stage filter circuit is connected to the microcontroller. The voltage divider circuit is connected between the switch control circuit and the two-stage filter circuit. The ESD protection circuit solves the problem of ordinary ESD capacitors being damaged by the battery pack voltage due to their low withstand voltage, and the two-stage filter circuit improves the anti-interference performance of the acquired voltage signal, thereby enabling safe and stable monitoring of the high-voltage battery voltage. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 A schematic diagram of a high-voltage acquisition circuit provided in an embodiment of this application;

[0038] Figure 2 A schematic diagram of a microcontroller provided for another embodiment of this application;

[0039] Figure 3 A schematic diagram of an electrostatic discharge protection circuit provided for another embodiment of this application;

[0040] Figure 4 A schematic diagram of a two-stage filter circuit provided for another embodiment of this application;

[0041] Figure 5 A schematic diagram of a first filter circuit provided for another embodiment of this application;

[0042] Figure 6 A schematic diagram of a second filter circuit provided for another embodiment of this application;

[0043] Figure 7 A schematic diagram of a switch control circuit provided for another embodiment of this application;

[0044] Figure 8 This is a schematic diagram of a high-voltage acquisition circuit provided for another embodiment of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0047] It should be noted that the information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0048] It should be noted that the concepts of "first" and "second" mentioned in this application are only used to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0049] It should be noted that the terms "a" and "a plurality of" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0050] This application provides a high-voltage acquisition circuit, such as... Figure 1 As shown, the specific steps include:

[0051] Electrostatic protection circuit 10, switch control circuit 20, voltage divider circuit 30, two-stage filter circuit 40, and microcontroller 50;

[0052] The switch control circuit 20 is connected to the output terminal of the electrostatic protection circuit 10, the input terminal of the secondary filter circuit 40, and the microcontroller, respectively; the input terminal of the electrostatic protection circuit 10 is connected to the power supply; the output terminal of the secondary filter circuit 40 is connected to the microcontroller 50; and the voltage divider circuit 30 is connected between the switch control circuit 20 and the secondary filter circuit 40.

[0053] It should be noted that the power source can be, but is not limited to, a battery pack; one end of the battery pack is grounded, and the other end is connected to the input terminal of the electrostatic protection circuit 10.

[0054] Optionally, in another embodiment of this application, one implementation of the microcontroller 50 is as follows: Figure 2 As shown, it includes:

[0055] Control signal pin 51 and analog input pin 52;

[0056] The switch control circuit 20 is connected to the output terminal of the electrostatic protection circuit 10, the input terminal of the secondary filter circuit 40, and the control signal pin 51, respectively; the output terminal of the secondary filter circuit 40 is connected to the analog input pin 52.

[0057] The control signal pin 51 (MCU_CTL) is used to drive the switching state or operating mode switching of external circuits (such as MOSFETs, relays, etc.).

[0058] Analog input pin 52 (MCU_AN_IN) is used to receive external analog signals (such as voltage, current, etc.) and convert them into digital values ​​for MCU processing.

[0059] Optionally, in another embodiment of this application, one implementation of the electrostatic protection circuit 10 is as follows: Figure 3 As shown, it includes:

[0060] First resistor 11, second resistor 12 and third resistor 13;

[0061] The first resistor 11 is connected to the second resistor 12 and the power supply respectively; the third resistor 13 is connected to the second resistor 12 and the switch control circuit 20 respectively.

[0062] In the specific implementation of this application, the first resistor 11, the second resistor 12 and the third resistor 13 are megohm-level large packages. The high resistance value reduces the current entering the analog input pin 52 (MCU_AN_IN) of the microcontroller 50 by static electricity, and protects the high voltage acquisition circuit from the static interference of the power supply.

[0063] Optionally, in another embodiment of this application, one implementation of the voltage divider circuit 30 includes:

[0064] Fourth resistor 31;

[0065] Among them, one end of the fourth resistor 31 is grounded, and the other end is connected between the switch control circuit 20 and the secondary filter circuit 40.

[0066] In the specific implementation of this application, the fourth resistor 31 is a small package in the kiloohm range.

[0067] Optionally, in another embodiment of this application, one implementation of the secondary filter circuit 40 is as follows: Figure 4 As shown, it includes:

[0068] First filter circuit 41 and second filter circuit 42;

[0069] The first filter circuit 41 is connected to the output terminal of the switch control circuit 20 and the input terminal of the second filter circuit 42, respectively; the output terminal of the second filter circuit 42 is connected to the microcontroller 50.

[0070] Specifically, in the actual application of this application, the output terminal of the second filter circuit 42 is connected to the analog input pin 52 (MCU_AN_IN) of the microcontroller 50.

[0071] It should be noted that, in the specific implementation of this application, the first filter circuit 41 is used to provide high-frequency wave performance; the second filter circuit 42 can provide good filtering across the entire frequency range from low to high. Through two-stage filtering, the high-frequency noise immunity performance of the analog input pin 52 (MCU_AN_IN) of the microcontroller 50 in the tens to hundreds of megahertz range can be improved, thereby enhancing the noise immunity capability of the microcontroller 50.

[0072] Optionally, in another embodiment of this application, one implementation of the first filter circuit 41 is as follows: Figure 5 As shown, it includes:

[0073] Magnetic bead 411 and first capacitor 412;

[0074] The ferrite bead 411 is connected to the output terminal of the switch control circuit 20 and the input terminal of the second filter circuit 40, respectively.

[0075] One end of the first capacitor 412 is grounded, and the other end is connected between the ferrite bead 411 and the input of the second filter circuit 42.

[0076] Among them, the ferrite bead 411 can be selected, but is not limited to, a ferrite bead with high impedance over a wide frequency range. There is no limitation here. Ferrite bead 411 has a large impedance near the high frequency of 100MHz and higher, which can provide better high frequency filtering performance. The first capacitor 412 is an nF level capacitor.

[0077] Optionally, in another embodiment of this application, one implementation of the first filter circuit 42 is as follows: Figure 6 As shown, it includes:

[0078] The fifth resistor is 421 and the second capacitor is 422;

[0079] The fifth resistor 421 is connected to the first filter circuit 41 and the microcontroller 50 respectively;

[0080] One end of the second capacitor 422 is grounded, and the other end is connected between the fifth resistor 421 and the microcontroller 50.

[0081] The fifth resistor, 421, is a small package in the kiloohm range. The second capacitor, 422, is an nF capacitor.

[0082] Specifically, in the actual application of this application, one end of the second capacitor 422 is grounded, and the other end is connected between the fifth resistor 421 and the analog input pin 52 (MCU_AN_IN) of the microcontroller 50.

[0083] Optionally, in another embodiment of this application, one implementation of the switch control circuit 20 is as follows: Figure 7 As shown, it includes:

[0084] N-type metal-oxide-semiconductor field-effect transistor 21, sixth resistor 22 and seventh resistor 23;

[0085] The N-type metal-oxide-semiconductor field-effect transistor 21 is connected to the output terminal of the electrostatic protection circuit 10, the input terminal of the secondary filter circuit 40, and one end of the seventh resistor 23; the other end of the seventh resistor 23 is connected to the microcontroller 50.

[0086] One end of the sixth resistor 22 is grounded, and the other end is connected between the N-type metal-oxide-semiconductor field-effect transistor 21 and the seventh resistor 23.

[0087] Among them, the sixth resistor 22 and the seventh resistor 23 are small packages in the kiloohm range.

[0088] It should be noted that the N-type metal-oxide-semiconductor field-effect transistor 21 is a high-voltage NMOS. Its gate is normally pulled down to ground by the sixth resistor 22, which is a low level, and the NMOS is in the off state. When the control signal pin 51 (MCU_CTL) of the microcontroller 50 is high, the N-type metal-oxide-semiconductor field-effect transistor 21 is turned on.

[0089] In the actual application of this application, after passing through the switch control circuit 20 and the two-stage filter circuit 40, the analog input pin 52 (MCU_AN_IN) of the microcontroller 50 acquires the voltage V1 on the fourth resistor 31, and after being converted and calculated by the internal voltage division ratio Vbat=V1(R1+R2+R3) / R4 in the software, the external battery pack voltage Vbat is obtained. Among them, R1 is the first resistor 11, R2 is the second resistor 12, R3 is the third resistor 13, and R4 is the fourth resistor 31.

[0090] like Figure 8The diagram shown is a schematic of a high-voltage acquisition circuit provided in this application, which includes: a battery pack, a control signal pin 51 (MCU_CTL), an analog input pin 52 (MCU_AN_IN), a first resistor 11 (R1), a second resistor 12 (R2), a third resistor 13 (R3), a fourth resistor 31, a ferrite bead 411 (R4), a first capacitor 412 (C1), a fifth resistor 421 (R5), a second capacitor 422 (C2), an N-type metal-oxide-semiconductor field-effect transistor 21 (Q1), a sixth resistor 22 (R6), and a seventh resistor 23 (R7). ESD protect represents the electrostatic discharge protection circuit, control represents the switch control circuit, and filter represents the secondary filter circuit.

[0091] R1, R2, R3, and R4 are current-limiting and voltage-dividing resistors. R1, R2, and R3 are in large packages with resistance values ​​in the M ohm range, which reduces the current entering the acquisition circuit due to static electricity. R4 is in a small package with resistance values ​​in the K ohm range. Q1 is a high-voltage NMOS. Normally, the gate of Q1 is pulled down to ground by R6, which is a low level, and the NMOS is in the off state. When the MCU_CTL control pin is high, Q1 is turned on. After two stages of filtering, MCU_AN_IN acquires the voltage V1 on R4, and after internal voltage division calculation using the software, the external battery pack voltage Vbat is obtained by the conversion Vbat = V1(R1+R2+R3) / R4. The first stage of the two-stage filter circuit consists of a ferrite bead L1 and a capacitor C1. Ferrite bead L1 has a large impedance near 100MHz and higher frequencies, providing good high-frequency filtering performance. The second stage consists of resistor R5 and capacitor C2, which can provide good filtering across the entire frequency band from low to high frequencies. Through two-stage filtering, the high-frequency anti-interference performance of the MCU_AN_IN acquisition circuit in the tens to hundreds of megahertz range can be improved, thus enhancing the anti-interference capability of the MCU_AN_IN acquisition circuit.

[0092] The resistors R1 / R2 / R3 are typically in the range of several hundred K to several M ohms. L1 is usually a ferrite bead with a wide frequency range and high impedance. C1 and C2 are nF level capacitors, and R4, R5, R6, and R7 are K level resistors.

[0093] In the practical application of this application, the optimal matching scheme is R1 is 2M ohms, R2 is 2M ohms, R3 is 2M ohms, R4 is 45.3K ohms, R5 is 1K ohms, R6 is 45.3K ohms, and R7 is 1K ohms; L1 is 330 ohms / 100M, C1 is 2.2nF, and C2 is 100nF.

[0094] As can be seen from the above scheme, this application provides a high-voltage acquisition circuit, which includes an electrostatic discharge (ESD) protection circuit, a switch control circuit, a voltage divider circuit, a two-stage filter circuit, and a microcontroller. The switch control circuit is connected to the output terminal of the ESD protection circuit, the input terminal of the two-stage filter circuit, and the microcontroller, respectively. The input terminal of the ESD protection circuit is connected to the power supply. The output terminal of the two-stage filter circuit is connected to the microcontroller. The voltage divider circuit is connected between the switch control circuit and the two-stage filter circuit. The ESD protection circuit solves the problem of ordinary ESD capacitors being broken down by the battery pack voltage due to their low withstand voltage, and the two-stage filter circuit improves the anti-interference performance of the acquired voltage signal, thereby enabling safe and stable monitoring of the high-voltage battery voltage.

[0095] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), and so on.

[0096] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in this application is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely exemplary forms of implementing this application.

[0097] While several specific implementation details are included in the foregoing discussion, these should not be construed as limiting the scope of this application. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0098] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described application concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions claimed in this application.

Claims

1. A high voltage acquisition circuit, characterized by, include: Electrostatic protection circuit, switch control circuit, voltage divider circuit, two-stage filter circuit, and microcontroller; The switch control circuit is connected to the output terminal of the electrostatic protection circuit, the input terminal of the secondary filter circuit, and the microcontroller, respectively; the input terminal of the electrostatic protection circuit is connected to the power supply. The output of the secondary filter circuit is connected to the microcontroller; the voltage divider circuit is connected between the switch control circuit and the secondary filter circuit.

2. The high-voltage acquisition circuit of claim 1, wherein, The electrostatic discharge protection circuit includes: First resistor, second resistor, and third resistor; The first resistor is connected to the second resistor and the power supply respectively; the third resistor is connected to the second resistor and the switch control circuit respectively.

3. The high-voltage acquisition circuit of claim 1, wherein, The voltage divider circuit includes: Fourth resistor; One end of the fourth resistor is grounded, and the other end is connected between the switch control circuit and the secondary filter circuit.

4. The high-voltage acquisition circuit of claim 1, wherein, The secondary filter circuit includes: First filter circuit and second filter circuit; The first filter circuit is connected to the output terminal of the switch control circuit and the input terminal of the second filter circuit, respectively; the output terminal of the second filter circuit is connected to the microcontroller.

5. The high-voltage acquisition circuit of claim 4, wherein, The first filter circuit includes: Ferrite bead and first capacitor; The magnetic beads are respectively connected to the output terminal of the switch control circuit and the input terminal of the second filter circuit; One end of the first capacitor is grounded, and the other end is connected between the ferrite bead and the input terminal of the second filter circuit.

6. The high-voltage acquisition circuit of claim 4, wherein, The second filter circuit includes: The fifth resistor and the second capacitor; The fifth resistor is connected to the first filter circuit and the microcontroller, respectively. One end of the second capacitor is grounded, and the other end is connected between the fifth resistor and the microcontroller.

7. The high-voltage acquisition circuit of claim 1, wherein, The switch control circuit includes: N-type metal-oxide-semiconductor field-effect transistor, sixth resistor and seventh resistor; The N-type metal-oxide-semiconductor field-effect transistor is connected to the output terminal of the electrostatic protection circuit, the input terminal of the secondary filter circuit, and one end of the seventh resistor, respectively; the other end of the seventh resistor is connected to the microcontroller. One end of the sixth resistor is grounded, and the other end is connected between the N-type metal-oxide-semiconductor field-effect transistor and the seventh resistor.

8. The high-voltage acquisition circuit according to claim 1, characterized in that, The power source is a battery pack; one end of the battery pack is grounded, and the other end is connected to the input terminal of the electrostatic protection circuit.

9. The high-voltage acquisition circuit according to claim 1, characterized in that, The microcontroller includes: Control signal pins and analog input pins; The switch control circuit is connected to the output terminal of the electrostatic protection circuit, the input terminal of the secondary filter circuit, and the control signal pin, respectively. The output terminal of the secondary filter circuit is connected to the analog input pin.

10. The high-voltage acquisition circuit of claim 2, wherein, The first resistor, the second resistor, and the third resistor are packaged in a megohm-class large package.

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