CN211785989U - Power battery total voltage detection circuit and equipment - Google Patents
Power battery total voltage detection circuit and equipment Download PDFInfo
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- CN211785989U CN211785989U CN201921219536.7U CN201921219536U CN211785989U CN 211785989 U CN211785989 U CN 211785989U CN 201921219536 U CN201921219536 U CN 201921219536U CN 211785989 U CN211785989 U CN 211785989U
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Abstract
The utility model discloses a power battery total voltage detection circuitry and equipment, include: the voltage division module is externally connected with a power battery, is respectively connected with the isolation amplification module and the control module, and is used for acquiring an analog voltage signal of the power battery after receiving a voltage acquisition instruction sent by the control module and outputting the analog voltage signal to the isolation amplification module; the isolation amplification module is connected with the analog-to-digital conversion module and used for amplifying the analog voltage signal to obtain an amplified analog voltage signal; the analog-to-digital conversion module is in communication connection with the control module through a Serial Peripheral Interface (SPI) and is used for converting the amplified analog voltage signal into a digital voltage signal; the control module is used for generating a voltage acquisition instruction according to the received voltage acquisition signal; and receiving and storing the digital voltage signal. The utility model discloses an adopt the high accuracy, adopt the analog-to-digital conversion module of resolution ratio, improved the detection precision of power battery total voltage.
Description
Technical Field
The embodiment of the utility model provides a relate to power battery detection technology field, especially relate to a power battery total voltage detection circuitry and equipment.
Background
With the progress of battery technology, pure electric vehicles gradually become popular in the market. In an electric vehicle, power is derived from a power battery integrated within the vehicle. If the power battery fails, the power battery may cause great harm to passengers and the automobile, so that the power battery needs to be managed correspondingly. One important content in the management of the power battery is to detect the total voltage of the battery, and the total voltage is used for diagnosis of an external relay and analysis of battery performance according to the total voltage value.
At present, a structure of a total voltage detection circuit of a power battery generally includes a solid-state switch, a voltage division module, an isolation amplification module, a differential amplification module, a filtering module, a Micro Control Unit (MCU), and the like, where errors of a voltage division resistor, an error of an operational amplification circuit, and a sampling error of the MCU all cause misalignment of total voltage detection. Among the above errors, sampling errors of the MCU analog input port have a large influence on the total voltage detection accuracy. But due to the sampling precision limit of the MCU, the measurement error is difficult to reduce. But due to the sampling precision limit of the MCU, the measurement error is difficult to reduce.
SUMMERY OF THE UTILITY MODEL
The utility model provides a power battery total voltage detection circuitry and equipment to the detection precision that provides power battery total voltage.
In a first aspect, the embodiment of the utility model provides a power battery voltage detection circuit, include: the device comprises a voltage division module, an isolation amplification module, an analog-to-digital conversion module and a control module; wherein the content of the first and second substances,
the voltage division module is externally connected with the power battery, is respectively connected with the isolation amplification module and the control module, and is used for acquiring an analog voltage signal of the power battery after receiving a voltage acquisition instruction sent by the control module and outputting the analog voltage signal to the isolation amplification module;
the isolation amplification module is connected with the analog-to-digital conversion module and used for amplifying the analog voltage signal to obtain an amplified analog voltage signal;
the analog-to-digital conversion module is in communication connection with the control module through a Serial Peripheral Interface (SPI) and is used for converting the amplified analog voltage signal into a digital voltage signal;
the control module is used for generating a voltage acquisition instruction according to the received voltage acquisition signal; and receiving and storing the digital voltage signal.
In a second aspect, an embodiment of the present invention provides an apparatus, which includes the power battery total voltage detection circuit as described in any of the above first aspects.
The embodiment of the utility model provides a pair of power battery total voltage detection circuitry and equipment, include: the voltage division module is externally connected with a power battery, is respectively connected with the isolation amplification module and the control module, and is used for acquiring an analog voltage signal of the power battery after receiving a voltage acquisition instruction sent by the control module and outputting the analog voltage signal to the isolation amplification module; the isolation amplification module is connected with the analog-to-digital conversion module and used for amplifying the analog voltage signal to obtain an amplified analog voltage signal; the analog-to-digital conversion module is in communication connection with the control module through a Serial Peripheral Interface (SPI) and is used for converting the amplified analog voltage signal into a digital voltage signal; the control module is used for generating a voltage acquisition instruction according to the received voltage acquisition signal; and receiving and storing the digital voltage signal. The utility model discloses an adopt the high accuracy, adopt the analog-to-digital conversion module of resolution ratio, improved the detection precision of power battery total voltage.
Drawings
Fig. 1 is a block diagram of a total voltage detection circuit of a power battery in an embodiment of the present invention;
fig. 2 is a structural diagram of a total voltage detection circuit of a power battery provided by the embodiment of the present invention;
fig. 3 is a schematic structural diagram of a voltage dividing module provided in an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a coupling switch provided in an embodiment of the present invention;
fig. 5 is a schematic structural diagram of an operational amplification unit provided in an embodiment of the present invention;
fig. 6 is a schematic diagram of a digital-to-analog conversion module and a control module according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Examples
Fig. 1 is a block diagram of a total voltage detection circuit of a power battery in an embodiment of the present invention; the embodiment is applicable to the condition of detecting the total voltage between the anode and the cathode of the power battery, the total voltage detection circuit of the power battery can be arranged in the detection equipment of the total voltage, and the total voltage detection circuit of the power battery can also be arranged in the management system of the power battery.
The power battery is a power supply for providing a power source for tools, and is a storage battery for providing power for electric automobiles, electric trains, electric bicycles and golf carts. The power battery in this embodiment is specifically a lithium battery for providing a power source for the tool. The power battery in this embodiment may be a single power battery, or a power battery pack formed by a plurality of lithium battery cells after being mixed and connected. The total voltage of the power battery is the total voltage between the anode and the cathode of the power battery.
As shown in fig. 1, the embodiment of the present invention provides a power battery total voltage detection circuit, which mainly includes the following modules: a voltage dividing module 110, an isolation amplifying module 120, an analog-to-digital conversion module 130 and a control module 140.
The voltage dividing module 110 is externally connected to the power battery 150, and is respectively connected to the isolation amplifying module 120 and the control module 140, and is configured to acquire an analog voltage signal of the power battery after receiving a voltage acquisition instruction sent by the control module, and output the analog voltage signal to the isolation amplifying module.
In this embodiment, the control module 140 refers to a device that can generate corresponding instructions according to signals output by a user. The control module 140 is preferably an upper computer. The control module 140 may receive a voltage acquisition signal input by a user through an input device. The input device can be a virtual key on a touch display screen of the upper computer, can also be a keyboard or a mouse and other devices connected with the upper computer, and can also be a physical key in the upper computer, for example: the button can be a positive voltage button, a negative voltage button, a processing button, etc.
After receiving the voltage acquisition signal input by the user, the control module 140 generates a voltage acquisition instruction and outputs the voltage acquisition instruction to the voltage division module 110, and after receiving the first detection instruction, the voltage division module 110 delays by 100ms to acquire an analog voltage signal of the power battery 150 and outputs the analog voltage signal to the isolation amplification module 120.
Further, in this embodiment, the voltage dividing module 110 collects the total voltage of the power battery by serially connecting resistors to divide the voltage.
The isolation amplifying module 120 is connected to the analog-to-digital conversion module 130, and configured to amplify the analog voltage signal to obtain an amplified analog voltage signal.
The isolation amplifying module 120 converts the analog voltage signal into a differential signal through the processing of the isolation optocoupler, and the differential signal is connected to two input pins of the operational amplifier. The operational amplifier amplifies the differential signal and outputs an amplified analog voltage signal to the analog-to-digital conversion module 130.
An analog-to-digital conversion module 130, which establishes a communication connection with the control module 140 through the serial peripheral interface SPI, and is configured to convert the amplified analog voltage signal into a digital voltage signal;
the analog-to-digital conversion module 130 may be a high-precision analog-to-digital conversion chip. In the present embodiment, 1 analog input channel is used and communicates with the control module 140 via SPI. The resolution ratio of the high-precision analog-to-digital conversion chip is 16 bits, and the sampling precision of the analog-to-digital conversion module is plus or minus 3.5 mV.
The control module 140 is configured to generate a voltage acquisition instruction according to the received voltage acquisition signal; and receiving and storing the digital voltage signal.
In this embodiment, the control module 140 may be a controller in an existing power battery management system. After acquiring the total voltage, the controller 140 may determine whether the total voltage meets the requirement according to actual needs, so as to further manage the power battery.
The embodiment of the utility model provides a pair of power battery total voltage detection circuitry, include: the voltage division module is externally connected with a power battery, is respectively connected with the isolation amplification module and the control module, and is used for acquiring an analog voltage signal of the power battery after receiving a voltage acquisition instruction sent by the control module and outputting the analog voltage signal to the isolation amplification module; the isolation amplification module is connected with the analog-to-digital conversion module and used for amplifying the analog voltage signal to obtain an amplified analog voltage signal; the analog-to-digital conversion module is in communication connection with the control module through a Serial Peripheral Interface (SPI) and is used for converting the amplified analog voltage signal into a digital voltage signal; the control module is used for generating a voltage acquisition instruction according to the received voltage acquisition signal; and receiving and storing the digital voltage signal. The utility model discloses an adopt the high accuracy, adopt the analog-to-digital conversion module of resolution ratio, improved the detection precision of power battery total voltage.
On the basis of the above-mentioned embodiment, the embodiment of the utility model provides a further optimized above-mentioned power electric power total voltage detection circuit. Fig. 2 is a structural diagram of a total voltage detection circuit of a power battery provided by the embodiment of the present invention. As shown in fig. 2, the first division module includes: a first pin 1, a second pin 2, a first switch unit 111, a second switch unit 112 and a first resistor R1.
A first end of the first pin 1 is externally connected with the anode of the power battery, and a second end of the first pin 1 is connected with a first end of the first switch unit 111; the first switch unit 111, the first resistor R1 and the second switch unit 112 are connected in sequence; a second end of the first switch unit 111 and a second end of the second switch unit 113 are respectively connected with the control module; the first end of the second pin 2 is externally connected with the negative electrode of the power battery, and the second end of the second pin 2 is connected with the first end of the second switch unit.
Further, the first switching unit 111 includes: a second resistor R2 and a first switch subunit 11; a first end of the second resistor R2 is connected to a second end of the first pin 1, and a second end of the second resistor R2 is connected to a first end of the first switch subunit 11; the second terminal of the first switch subunit 11 is connected to the control module, and the third terminal of the first switch subunit 11 is connected to the first terminal of the first resistor R1.
Further, the second switching unit 112 includes: a fourth resistor R4 and a second switch subunit 12; a first end of the fourth resistor R4 is connected to the second end of the second pin 2, and a second end of the fourth resistor R4 is connected to the first end of the second switch subunit 12; a second terminal of the second switching subunit 12 is connected to the control module, and a third terminal of the second switching subunit 12 is connected to a second terminal of the first resistor R1.
Further, as shown in fig. 2, the isolation amplifying module includes: the optical coupler isolation unit U1 and the differential amplification unit U2; a first end of the optical coupling isolation unit U1 is connected with a first end of a first resistor R1, a second end of the optical coupling isolation unit U1 is connected with a second end of a first resistor R1, a third end of the optical coupling isolation unit U1 is connected with a first end of a differential amplification unit U2, and a fourth end of the optical coupling isolation unit U1 is connected with a second end of a differential amplification unit U2; the third end of the differential amplifying unit U2 is connected with the analog-to-digital conversion module U3.
In fig. 2, point a is the positive electrode of the power battery, and point B is the negative electrode of the power battery. Two wires are led out from A, B and connected to two pins of a Battery Management System (BMS) connector respectively, and high voltage is led into the BMS controller. At this time, it should be noted that the distance between the positive electrode of the power battery and the negative electrode contact pin and the wiring distance on the PCB board should meet the requirement of high-voltage creepage distance.
In the embodiment, the control module is preferably a single chip microcomputer U4.
Generally, the port of the analog-to-digital conversion unit in the single chip microcomputer can detect the analog quantity input of 0-5V, but the voltage range of the power battery is usually larger than 350V, so when high voltage is introduced into the BMS, the voltage division process is firstly carried out. In the BMS controller, a pin 1 corresponding to the positive pole of the power battery is connected to a first switch subunit 11 through a second resistor R2, and the on and off of the first switch subunit 11 are controlled by a low-voltage logic circuit of a single chip microcomputer U4. The other side of the first switch subunit 11 is connected in series with a first resistor R1, the other side of the first resistor R1 is connected in series with the second switch subunit 12, and the other side of the second switch subunit 12 is connected in series with a fourth resistor R4. The other end of the fourth resistor R4 is connected to the second pin 2.
It should be noted that the first switch subunit 11 and the second switch subunit 12 are both optical coupling switches. The first resistor R1, the second resistor R2, and the fourth resistor R4 do not refer to a resistor device, but refer to a device or a structure having a resistance function, and may be a resistor device, or a topology in which a plurality of resistor devices are connected in series, in parallel, or in series-parallel. In the present embodiment, only the first resistor R1, the second resistor R2, and the seventh resistor R7 are illustrated, but not limited. The content of the description in the above paragraph is a resistance voltage division circuit after the positive electrode and the negative electrode of the power battery are introduced into the BMS.
In the present embodiment, the first PIN 1 and the second PIN 2 are 8PIN connectors. The creepage distance of the connector meets the requirement of high-voltage collection and passes the certification of the automobile grade of the parts. It should be noted that, in the present embodiment, only the first pin 1 and the second pin 2 are illustrated, but not limited to, and other types of pins may be selected according to actual situations.
The optical coupling switch is selected to be of the type ACPL-C87AT, and it is to be understood that the optical coupling switch need not be a device of the above type, and this is merely an example. The input allowable input range of the isolation amplifier is 0-2V, so the voltage V1 obtained by dividing the voltage through the resistor should satisfy the allowable input range of the isolation amplifier.
The on-resistance of the optocoupler switch in the on state is negligible compared with the sum of the series resistors R1+ R2+ R4. Therefore, the resistances of the first resistor R1, the second resistor R2 and the fourth resistor R4 are determined through the following three steps. Preferably, an appropriate bus voltage sense current (ISENSE) is selected. The magnitude of the resistance of the first resistor R1 is determined by the following equation. R1 ═ V1/Isense, where V1 ═ 2V. And according to the obtained value of the first resistor R1, the voltage range of the power battery is integrated, and the sum of the second resistor R2 and the fourth resistor R4 is determined.
In a preferred embodiment, the first resistor R1 is a series of 2 1K Ω resistors, with a total resistance of 2K Ω; the second resistor R2 is formed by connecting 3 100K omega resistors in series, and the total resistance is 300K omega; the fourth resistor R4 is a series of 3 100K Ω resistors with a total resistance of 300K Ω. It should be noted that the resistances of the first resistor R1, the second resistor R2, and the fourth resistor R4 may be selected according to actual situations, and the resistance values provided in this embodiment are only a specific example, and this embodiment is only for illustration and is not limited.
Further, fig. 3 is a schematic structural diagram of a voltage dividing module provided in an embodiment of the present invention; as shown in fig. 3, the first switch subunit includes: the first coupling switch U5, the third resistor R3 and the first power tube Q1; a first end of the first coupling switch U5 is connected to a second end of the second resistor R2, and a second end of the first coupling switch U5 is connected to a first end of the first resistor R1; the third end of the first coupling switch U5 is externally connected with the power supply module through a third resistor R3; the fourth end of the first coupling switch U5 is connected with the first end of the first power tube Q1; the second end of the first power tube Q1 is connected with the control module, and the third end of the first power tube Q1 is grounded.
The second switch subunit includes: the second coupling switch U6, a fifth resistor R5 and a second power tube Q2; a first end of the second coupling switch U6 is connected to a second end of the fourth resistor R4, and a second end of the second coupling switch U6 is connected to a second end of the first resistor R1; the third end of the second coupling switch U6 is externally connected with the power supply module through a fifth resistor R5; the fourth end of the second coupling switch U6 is connected with the first end of a second power tube Q2; the second end of the second power tube Q2 is connected with the control module, and the third end of the second power tube Q2 is grounded.
Fig. 4 is a schematic structural diagram of a coupling switch provided in an embodiment of the present invention; the first coupling switch U5 and the second coupling switch U6 respectively include a control side diode and an output side MOSFET two-part structure. For the low-voltage control loop in fig. 2, the first end of the third resistor R3 is connected to the 5V power supply inside the BMS, the second end of the third resistor R3 is connected to the anode of the diode (pin 1 in fig. 4) on the control side of the first coupling switch U5, the cathode of the diode (pin 2 in fig. 4) is connected to the collector of the first power transistor Q1, the base of the first power transistor Q1 is connected to the GPIO1 port of the MCU, the emitter of the first power transistor Q1 is connected to the low-voltage ground inside the BMS, the first end of the second resistor R2 is connected to the first pin 1, the second end of the second resistor R2 is connected to the first end of the first coupling switch U5 (pin 8 in fig. 4), and the second end of the first coupling switch U5 of the first resistor R1 (pin 7 in fig. 4).
The first end of the fifth resistor R5 is connected to the 5V power supply inside the BMS, the second end of the fifth resistor R5 is connected to the anode (pin 3 in fig. 4) of the diode on the control side of the second coupling switch U6, the cathode (pin 4 in fig. 4) of the diode is connected to the collector of the second power transistor Q2, the base of the second power transistor Q2 is connected to the GPIO2 port of the MCU, the emitter of the second power transistor Q2 is connected to the low voltage ground inside the BMS, the first end of the fourth resistor R4 is connected to the second pin 2, the second end of the fourth resistor R4 is connected to the first end (pin 6 in fig. 4) of the second coupling switch U6, and the second end of the first resistor R1 is connected to the second end (pin 5 in fig. 4) of the second coupling switch U6.
When the BMS is powered on and initialized, the MCU pins GPIO1 and GOPI2 are at a low level, and the NPN transistors Q1 and Q2 are turned off. When the BMS detects the total voltage of the power battery, GPIO1 and GPIO2 are set to high level. When GPIO1 and GPIO2 are set to high, the corresponding transistor will be in a conducting state. For the upper half-bridge circuit, the on-state current ION1 is mainly determined by the voltage of 5V, the third resistor R3, the diode conducting voltage drop of the first coupled switch U5, and the conducting voltage drop of the transistor Q1. For the lower half-bridge circuit, the on-current ION2 is mainly determined by the voltage of 5V, the fifth resistor R5, the diode conducting voltage drop in the second coupled switch U6, and the conducting voltage drop of the transistor Q2. The resistance values of the third resistor R3 and the fifth resistor R5 should satisfy the condition that when the first power transistor Q1 and the second power transistor Q2 are in the on state, the LED diodes inside the first coupling switch U1 and the second coupling switch U2 should not operate in the over-current state.
In this embodiment, the first coupling switch U1 and the second coupling switch U2 are opto-coupler relays (Photo relays) with model of AQV258HAX _ C88, the opto-coupler relays have two sets of channels, and the first power transistor Q1 and the second power transistor Q2 are triodes with model of PUMH 11. In the present embodiment, only the model of the coupling switch and the model of the power tube are illustrated by way of example and not limitation.
Fig. 5 is a schematic structural diagram of an operational amplification unit provided in an embodiment of the present invention; as shown in fig. 5, the differential amplifying unit includes: a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and an operational amplifier U7; a first end of the sixth resistor R6 is connected with a third end of the optical coupling isolation unit U1, and a second end of the sixth resistor R6 is connected with a positive input end of the operational amplifier U7; a first end of the seventh resistor R7 is connected with the fourth end of the optical coupling isolation unit U1, and a second end of the seventh resistor R7 is connected with the negative input end of the operational amplifier U7; the negative input end of the operational amplifier U7 is connected with the output end of the operational amplifier U7 through an eighth resistor R8, and the output end of the operational amplifier U7 is connected with the control module.
The voltage at the two ends of the first resistor R1 is connected to the voltage input pin of the optical coupling isolation unit U1 through a filter circuit. The transmission medium of the optical coupling isolation unit U1 is light, and the high-voltage circuit and the low-voltage circuit cannot be directly electrically connected, so an isolation optical coupler needs to be used. Therefore, reliable transmission of voltage information can be guaranteed, and insulation between the high-voltage circuit and the low-voltage circuit can be guaranteed.
In the present embodiment, the voltage across the first resistor R1 is connected to the voltage input terminal of the optical coupling isolation unit U1 through an anti-aliasing low pass filter circuit. For the isolated optocoupler type selected in this example, the bandwidth of the filter circuit must be less than 410KHz and the capacitance must be greater than 1nF, and the appropriate low pass filter resistance value is selected according to the above conditions. Meanwhile, in order to reduce a voltage acquisition error caused by the output impedance of the isolation optocoupler, the values of the sixth resistor R6 and the seventh resistor R7 are required to be greater than 20K omega.
As shown in fig. 5, on the other side of the optical coupler isolation unit U1, the voltage information obtained by voltage division will be converted into differential signals (Vout + and Vout-) through the processing of the isolation optical coupler and connected to two input pins of the operational amplifier. The VOUT + differentially output by the optical coupling isolation unit U1 is connected to one side of a sixth resistor R6, the other side of the sixth resistor R6 is connected to the same-direction input end of the operational amplifier U7, VOUT-differentially output by the optical coupling isolation unit U1 is connected to one side of a seventh resistor R7, and the other side of the seventh resistor R7 is connected to the reverse input end of the operational amplifier U7. The eighth resistor R8 is a feedback resistor, one side of the eighth resistor R8 is connected to the inverting input terminal of the operational amplifier U7, and the other side is connected to the output terminal VOUT of the operational amplifier U7. The operational amplifier U7 has a certain voltage gain, and the specific gain value is determined by discrete devices outside the operational amplifier U7.
In this example, the GAIN of the operational amplifier U7 is determined by the ratio of the eighth resistor R8 and the seventh resistor R7, i.e., GAIN R8/R7. Wherein, R8 is the resistance of the eighth resistor R8, and R7 is the resistance of the seventh resistor R7. In this example, the eighth resistor R8 has a resistance of 47K Ω, and the seventh resistor R7 has a resistance of 22.1K Ω, so the operational amplifier GAIN is 2.13.
It should be noted that the resistances of the seventh resistor R7 and the eighth resistor R8 are not necessarily the same as those described above, and are only used as examples.
Fig. 6 is the embodiment of the utility model provides a digital-to-analog conversion module and control module's schematic diagram, as shown in fig. 6, the single-ended voltage signal VOUT of operational amplifier U7 output is received in the analog quantity input port of high accuracy analog-to-digital conversion chip, through the inside conversion of high accuracy ADC chip, carries out data communication through SPI and singlechip MCU. In this example, the output port VOUT of the operational amplifier U7 is connected to the analog input pin of the high-precision ADC.
The high-precision analog-digital conversion chip I has 4 analog quantity input channels in total and is communicated with the single chip microcomputer through the SPI. MPC5644 chip that singlechip MCU adopted. The resolution of the high-precision analog-to-digital conversion chip is 16 bits, and the resolution of the built-in analog-to-digital converter of the MCU is 12 bits. In an actual circuit, the sampling precision of the MCU is plus or minus 20mV, and the sampling precision of the high-precision analog-to-digital conversion chip is plus or minus 3.5mV, so the total voltage detection precision can be effectively improved through the high-precision ADC.
On the basis of the above embodiment, the embodiment of the utility model provides an equipment is still provided, equipment includes arbitrary power battery total voltage detection circuit in the above-mentioned embodiment.
The embodiment of the utility model provides an equipment can include the utility model discloses the total voltage detection circuit of power battery that arbitrary embodiment provided possesses corresponding functional module and beneficial effect of above-mentioned circuit.
It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.
Claims (10)
1. A power battery total voltage detection circuit is characterized by comprising: the device comprises a voltage division module, an isolation amplification module, an analog-to-digital conversion module and a control module; wherein the content of the first and second substances,
the voltage division module is externally connected with the power battery, is respectively connected with the isolation amplification module and the control module, and is used for acquiring an analog voltage signal of the power battery after receiving a voltage acquisition instruction sent by the control module and outputting the analog voltage signal to the isolation amplification module;
the isolation amplification module is connected with the analog-to-digital conversion module and used for amplifying the analog voltage signal to obtain an amplified analog voltage signal;
the analog-to-digital conversion module is in communication connection with the control module through a Serial Peripheral Interface (SPI) and is used for converting the amplified analog voltage signal into a digital voltage signal;
the control module is used for generating a voltage acquisition instruction according to the received voltage acquisition signal; and receiving and storing the digital voltage signal.
2. The circuit of claim 1, wherein the voltage divider module comprises: the circuit comprises a first contact pin, a second contact pin, a first switch unit, a second switch unit and a first resistor;
the first end of the first contact pin is externally connected with the anode of a power battery, and the second end of the first contact pin is connected with the first end of the first switch unit;
the first switch unit, the first resistor and the second switch unit are connected in sequence; the second end of the first switch unit and the second end of the second switch unit are respectively connected with the control module;
the first end of the second contact pin is externally connected with the negative electrode of the power battery, and the second end of the second contact pin is connected with the first end of the second switch unit.
3. The circuit of claim 2, wherein the first switching unit comprises: a second resistor and a first switch subunit; wherein the content of the first and second substances,
the first end of the second resistor is connected with the second end of the first contact pin, and the second end of the second resistor is connected with the first end of the first switch subunit;
the second end of the first switch subunit is connected with the control module, and the third end of the first switch subunit is connected with the first end of the first resistor.
4. The circuit of claim 3, wherein the first switch subunit comprises: the first coupling switch, the third resistor and the first power tube; wherein the content of the first and second substances,
a first end of the first coupling switch is connected with a second end of the second resistor, and a second end of the first coupling switch is connected with a first end of the first resistor; the third end of the first coupling switch is externally connected with a power supply module through the third resistor; the fourth end of the first coupling switch is connected with the first end of the first power tube;
the second end of the first power tube is connected with the control module, and the third end of the first power tube is grounded.
5. The circuit of claim 2, wherein the second switching unit comprises: a fourth resistor and a second switch subunit; wherein the content of the first and second substances,
a first end of the fourth resistor is connected with a second end of the second contact pin, and a second end of the fourth resistor is connected with a first end of the second switch subunit;
and the second end of the second switch subunit is connected with the control module, and the third end of the second switch subunit is connected with the second end of the first resistor.
6. The circuit of claim 5, wherein the second switch subunit comprises: the second coupling switch, the fifth resistor and the second power tube; wherein the content of the first and second substances,
a first end of the second coupling switch is connected with a second end of the fourth resistor, and a second end of the second coupling switch is connected with a second end of the first resistor; the third end of the second coupling switch is externally connected with a power supply module through the fifth resistor; the fourth end of the second coupling switch is connected with the first end of the second power tube;
and the second end of the second power tube is connected with the control module, and the third end of the second power tube is grounded.
7. The circuit of claim 2, wherein the isolation amplification module comprises: the optical coupling isolation unit and the differential amplification unit;
the first end of the optical coupling isolation unit is connected with the first end of the first resistor, the second end of the optical coupling isolation unit is connected with the second end of the first resistor, the third end of the optical coupling isolation unit is connected with the first end of the differential amplification unit, and the fourth end of the optical coupling isolation unit is connected with the second end of the differential amplification unit;
and the third end of the differential amplification unit is connected with the analog-to-digital conversion module.
8. The circuit according to claim 7, wherein the differential amplifying unit comprises: a sixth resistor, a seventh resistor, an eighth resistor, and an operational amplifier; wherein the content of the first and second substances,
a first end of the sixth resistor is connected with a third end of the optical coupling isolation unit, and a second end of the sixth resistor is connected with a positive input end of the operational amplifier;
a first end of the seventh resistor is connected with a fourth end of the optical coupling isolation unit, and a second end of the seventh resistor is connected with a negative input end of the operational amplifier;
the negative input end of the operational amplifier is connected with the output end of the operational amplifier through the eighth resistor, and the output end of the operational amplifier is connected with the control module.
9. The circuit of any one of claims 1-8, wherein the analog-to-digital conversion module is a high-precision analog-to-digital conversion chip, the resolution of the high-precision analog-to-digital conversion chip is 16 bits, and the sampling precision of the analog-to-digital conversion module is plus or minus 3.5 mV.
10. An apparatus, characterized in that the apparatus comprises a power battery total voltage detection circuit according to any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN113514692A (en) * | 2021-07-16 | 2021-10-19 | 国网江苏省电力有限公司检修分公司 | Transformer substation secondary circuit node voltage monitoring device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113514692A (en) * | 2021-07-16 | 2021-10-19 | 国网江苏省电力有限公司检修分公司 | Transformer substation secondary circuit node voltage monitoring device |
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