CN211043618U - Detection circuit and equipment for insulation resistance - Google Patents
Detection circuit and equipment for insulation resistance Download PDFInfo
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- CN211043618U CN211043618U CN201921127435.7U CN201921127435U CN211043618U CN 211043618 U CN211043618 U CN 211043618U CN 201921127435 U CN201921127435 U CN 201921127435U CN 211043618 U CN211043618 U CN 211043618U
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Abstract
The utility model discloses a detection circuit and equipment of insulation resistance, which collects the anode analog voltage signal of a power battery and outputs the anode analog voltage signal to an analog-to-digital conversion module after receiving a first detection instruction sent by a control module through a first detection module; the second detection module collects a negative electrode analog voltage signal of the power battery after receiving a second detection instruction sent by the control module and outputs the negative electrode analog voltage signal to the analog-to-digital conversion module; the analog-to-digital conversion module is used for converting the anode analog voltage signal into an anode digital voltage signal; converting the negative analog voltage signal into a negative digital voltage signal; and the control module is used for determining the insulation resistance of the power battery according to the positive digital voltage signal and the negative digital voltage signal. The utility model discloses an adopt the high accuracy, adopt the analog-to-digital conversion module of resolution ratio, improved insulation resistance's detection precision.
Description
Technical Field
The embodiment of the utility model provides a power battery detects technical field, especially relates to an insulation resistance's 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 insulation resistance of the battery and judge the quality of the insulation performance of the power battery according to the insulation resistance value.
At present, a commonly used insulation resistance detection circuit of a power battery is a bridge detection circuit, and the bridge detection circuit generally comprises an optical coupling switch module, a detection module, an isolation module, a Micro Control Unit (MCU) and the like. Errors of the detection module, errors of the isolation module, sampling errors of the MCU, etc. all cause misalignment of the insulation resistance detection. Among the above errors, the sampling error of the MCU analog input port has a large influence on the resistance detection accuracy. 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 an insulation resistance's detection circuitry and equipment to improve insulation resistance's detection precision.
In a first aspect, an embodiment of the present invention provides a detection circuit for insulation resistance, the circuit includes: the device comprises a first detection module, a second detection module, an analog-to-digital conversion module and a control module; wherein the content of the first and second substances,
the first detection module is externally connected with the anode of the power battery, is respectively connected with the analog-to-digital conversion module and the control module, and is used for acquiring an anode analog voltage signal of the power battery after receiving a first detection instruction sent by the control module and outputting the anode analog voltage signal to the analog-to-digital conversion module;
the second detection module is externally connected with the cathode of the power battery, is respectively connected with the analog-to-digital conversion module and the control module, and is used for acquiring a cathode analog voltage signal of the power battery after receiving a second detection instruction sent by the control module and outputting the cathode analog voltage signal to the analog-to-digital conversion module;
the analog-to-digital conversion module is connected with the control module and is used for converting the anode analog voltage signal into an anode digital voltage signal; converting the negative analog voltage signal into a negative digital voltage signal;
and the control module is used for determining the insulation resistance of the power battery according to the positive digital voltage signal and the negative digital voltage signal.
In a second aspect, an embodiment of the present invention provides an apparatus, which includes the detection circuit of the insulation resistance as described in the first aspect above.
The embodiment of the utility model provides a detection circuitry and equipment of insulation resistance, through first detection module after receiving the first detection instruction that control module sent, gather power battery's anodal analog voltage signal, and export to analog-to-digital conversion module; the second detection module collects a negative electrode analog voltage signal of the power battery after receiving a second detection instruction sent by the control module and outputs the negative electrode analog voltage signal to the analog-to-digital conversion module; the analog-to-digital conversion module is used for converting the anode analog voltage signal into an anode digital voltage signal; converting the negative analog voltage signal into a negative digital voltage signal; and the control module is used for determining the insulation resistance of the power battery according to the positive digital voltage signal and the negative digital voltage signal. The utility model discloses an adopt the high accuracy, adopt the analog-to-digital conversion module of resolution ratio, improved insulation resistance's detection precision.
Drawings
Fig. 1 is a block diagram of a detection circuit of an insulation resistance according to an embodiment of the present invention;
fig. 2 is a structural diagram of a detection circuit of another insulation resistance provided in the embodiment of the present invention;
fig. 3a is a schematic structural diagram of a first switch unit provided in an embodiment of the present invention;
fig. 3b is a schematic structural diagram of a second switch unit provided in the embodiment of the present invention;
fig. 4a is a schematic structural diagram of a first isolation subunit provided in an embodiment of the present invention;
fig. 4b is a schematic structural diagram of a second isolation subunit provided in an embodiment of the present invention;
fig. 5 is a schematic diagram of an operational amplifier provided by 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 the embodiment of the utility model provides an in the embodiment of the structure block diagram of insulation resistance's detection circuitry, this embodiment is applicable in the condition of detecting the insulation resistance value of power battery between to the automobile body ground, and this insulation resistance's detection circuitry can set up in insulation resistance's check out test set.
Insulation resistance is the most basic insulation index for electrical equipment and electrical lines. The insulation resistance is a resistance value corresponding to a leakage current flowing through the insulating material. The insulation resistance in this embodiment is a resistance value between a power battery in a pure electric vehicle and a vehicle body ground (i.e., to the ground). In this embodiment, the insulation resistor includes a resistance value of the positive pole of the power battery to ground, a resistance value of the negative pole of the power battery to ground, and a resistance value of the bipolar pole of the power battery to ground.
As shown in fig. 1, an embodiment of the present invention provides a detection circuit for an insulation resistor, which mainly includes the following modules: a first detection module 110, a second detection module 120, an analog-to-digital conversion module 130, and a control module 140. Wherein the content of the first and second substances,
the first detection module 110 is externally connected to the positive electrode of the power battery 150, and is respectively connected to the analog-to-digital conversion module 130 and the control module 140, and is configured to collect a positive electrode analog voltage signal of the power battery 150 after receiving a first detection instruction sent by the control module 140, and output the positive electrode analog voltage signal to the analog-to-digital conversion module 130.
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 may be 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 positive voltage acquisition signal input by the user, the control device 140 generates a first detection instruction and outputs the first detection instruction to the first detection module 110, and after receiving the first detection instruction, the first detection module 110 delays for 100ms to acquire the positive analog voltage signal of the power battery 150 and outputs the positive analog voltage signal to the analog-to-digital conversion module 130.
The second detection module 120 is externally connected to the negative electrode of the power battery 150, and is respectively connected to the analog-to-digital conversion module 130 and the control module 140, and is configured to collect a negative electrode analog voltage signal of the power battery after receiving a second detection instruction sent by the control module 140, and output the negative electrode analog voltage signal to the analog-to-digital conversion module 130.
After receiving the negative voltage acquisition signal input by the user, the control device 140 generates a second detection instruction and outputs the second detection instruction to the second detection module 110, and after receiving the second detection instruction, the second detection module 110 delays by 100ms to acquire an analog voltage signal of the negative electrode of the power battery 150 and outputs the analog voltage signal to the analog-to-digital conversion module 130.
In this embodiment, the first detection module 110 and the second detection module 120 cannot simultaneously collect voltage signals, that is, when the first detection module 110 collects positive analog voltage signals, the second detection module 120 does not work; that is, when the second detection module 120 collects the negative analog voltage signal, the first detection module 110 does not operate.
An analog-to-digital conversion module 130, which establishes a communication connection with the control module 140 through a Serial Peripheral Interface (SPI), and is configured to convert the positive analog voltage signal into a positive digital voltage signal; and converting the cathode analog voltage signal into a cathode digital voltage signal.
The analog-to-digital conversion module 130 may be an analog-to-digital conversion chip. In this embodiment, 4 analog input channels are used and communicate with the control module 140 via SPI. The resolution of the analog-to-digital conversion module 140 is 16 bits, and the sampling precision of the analog-to-digital conversion module is plus or minus 3.5 mV. The detection precision of the insulation resistance can be effectively improved.
And the control module 140 is used for determining the insulation resistance of the power battery according to the positive digital voltage signal and the negative digital voltage signal.
In the embodiment, the control module 140 calculates the positive pole-to-ground insulation resistance Rp and the negative pole-to-ground insulation resistance Rn of the power battery according to the positive pole digital voltage signal, the negative pole digital voltage signal, the circuit topology relationship and device parameters in the circuit. And calculating the bipolar ground resistance through the positive pole ground insulation resistance Rp and the negative pole ground insulation resistance Rn.
Since the positive ground insulation resistance Rp and the negative ground insulation resistance Rn are not resistance devices that are present in full, but have a resistance value corresponding to a current flowing when a current flows through an insulating material, the positive ground insulation resistance Rp and the negative ground insulation resistance Rn are indicated by broken lines in fig. 1.
The embodiment of the utility model provides a detection circuitry of insulation resistance, through first detection module after receiving the first detection instruction that control module sent, gather power battery's anodal analog voltage signal, and export to analog-to-digital conversion module; the second detection module collects a negative electrode analog voltage signal of the power battery after receiving a second detection instruction sent by the control module and outputs the negative electrode analog voltage signal to the analog-to-digital conversion module; the analog-to-digital conversion module is used for converting the anode analog voltage signal into an anode digital voltage signal; converting the negative analog voltage signal into a negative digital voltage signal; and the control module is used for determining the insulation resistance of the power battery according to the positive digital voltage signal and the negative digital voltage signal. The utility model discloses an adopt the high accuracy, adopt the analog-to-digital conversion module of resolution ratio, improved insulation resistance's detection precision.
On the basis of the above-mentioned embodiment, the embodiment of the utility model provides a further optimized above-mentioned insulation resistance's detection circuitry. Fig. 2 is a structural diagram of another insulation resistance detection circuit according to an embodiment of the present invention. As shown in fig. 2, the first detection module includes: the first pin 1, the first detection unit 201 and the first isolation unit 202, the second detection module includes: a second pin 2, a second detection unit 203, and a second isolation unit 204.
A first end of the first pin 1 is externally connected with a positive electrode of the power battery 207, and a second end of the first pin 1 is connected with a first end of the first detection unit 201; a second end of the first detection unit 201 is connected with the analog-to-digital conversion module 205 through the first isolation unit 202, and a third end of the first detection unit 201 is connected with the control module 206; a first end of the second pin 2 is externally connected with a negative electrode of the power battery 207, and a second end of the second pin 2 is connected with a first end of the second detection unit 203; a second end of the second detecting unit 203 is connected to the analog-to-digital conversion module 205 through the second isolating unit 205, and a third end of the second detecting unit 203 is connected to the control module.
In this embodiment, the analog-to-digital conversion module 205 includes a first analog-to-digital conversion unit ADC1 and a second analog-to-digital conversion unit ADC 2. The first isolation unit 202 is connected to the control module 206 via a first analog-to-digital conversion unit ADC 1. The second isolation unit 204 is connected to the control module 206 via a second analog-to-digital conversion unit ADC 2.
A circuit formed by connecting the first pin 1, the first detection unit 201, the first isolation unit 202 and the first analog-to-digital conversion unit ADC1 is referred to as an upper arm circuit of the detection circuit. The circuit formed by connecting the second pin 2, the second detection unit 203, the second isolation unit 204 and the second analog-to-digital conversion unit ADC2 is referred to as a lower arm circuit of the detection circuit.
The first detection unit 201 includes: the circuit comprises a first resistor R1, a second resistor R2 and a first switch subunit 11, wherein a first pin 1 is connected with a first end of the first switch subunit 11 through a first resistor R1, a second end of the first switch subunit 11 is connected with a first isolation unit 202 through a second resistor R2, and a third end of the first switch subunit 11 is connected with the control module 206.
The second detection unit 203 includes: the switch comprises a third resistor R3, a fourth resistor R4 and a second switch subunit 21, wherein the second pin 2 is connected with the first end of the second switch subunit 21 through the third resistor R4, the second end of the second switch subunit 21 is connected with the second isolation unit 202 through the second resistor R2, and the third end of the second switch subunit 203 is connected with the control module 206.
The first isolation unit 202 includes: a seventh resistor R7 and a first isolation subunit 2021, the second isolation unit 204 includes: eighth resistor R8 and second isolated subunit 2041; the first end of the first isolation subunit 2021 is grounded through a seventh resistor R7, the first end of the first isolation subunit 2021 is connected to the second resistor R2, and the second end of the first isolation subunit 2021 is connected to the analog-to-digital conversion module 205. A first end of the second isolation subunit 2041 is externally connected to a power supply module VCC through an eighth resistor R8, a first end of the second isolation subunit 2041 is connected to a fourth resistor R4, and a second end of the second isolation subunit 2041 is connected to the analog-to-digital conversion module 205.
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.
The upper bridge arm circuit is connected with the positive electrode of the power battery 207, and is connected into the BMS controller through a first pin 1. The first pin 1 is connected to a first terminal of a first resistor R1, a second terminal of the first resistor R1 is connected to a first terminal of the first switch subunit 11, and the on/off of the first switch subunit 11 is controlled by the low-voltage logic circuit of the control module 206. The second terminal of the first switch subunit 11 is connected to the first terminal of the second resistor R2, the first terminal of the second resistor R2 is connected to the first terminal of the seventh resistor R7, and the second terminal of the seventh resistor R7 is connected to the ground plane of the BMS controller, i.e., the vehicle body ground. The seventh resistor R7 is a pull-down resistor.
It should be noted that the first resistor R1, the second resistor R2, and the seventh resistor R7 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 resistors 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.
And the lower bridge arm circuit is connected with the cathode of the power battery and is connected into the BMS controller through a second contact pin 2. The second pin 2 is connected with a first end of a lower bridge arm third resistor R3, a second end of the third resistor R3 is connected with a first end of a second switch subunit 21, and the on and off of the second switch subunit 21 are controlled by a low-voltage logic circuit inside the BMS. The second terminal of the second switch subunit 21 is connected to the first terminal of the fourth resistor R4, the second terminal of the fourth resistor R4 is connected to the first terminal of the eighth resistor R8, and the second terminal of the eighth resistor R8 is connected to the VCC power supply inside the BMS controller.
In the upper bridge arm circuit and the lower bridge arm circuit, each circuit comprises an isolation unit which mainly plays an isolation role and can reduce sampling errors.
It should be noted that the third resistor R3, the fourth resistor R4, and the eighth resistor R8 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 resistors are connected in series, in parallel, or in series-parallel. In the present embodiment, only the third resistor R3, the fourth resistor R4, and the eighth resistor R8 are described, but not limited.
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 distance between the first pin 1 and the second pin 2 is described, but not limited to this, and other types of pins may be selected according to actual situations.
In this embodiment, the first resistor R1 is formed by connecting 6 resistors of 100K Ω in series, and the total resistance is 600K Ω; the second resistor R2 is formed by connecting 5 100K omega resistors in series, and the total resistance is 500K omega; the seventh resistor R7 is a resistor of 1K omega connected in series with a resistor of 10K omega, and the total resistance is 11K omega; the third resistor R3 is formed by connecting 6 resistors of 100K omega in series, and the total resistance is 600K omega; the fourth resistor R4 is formed by connecting 5 resistors of 100K omega in series, and the total resistance is 500K omega; the eighth resistor R8 is a series connection of a 1K Ω resistor and a 10K Ω resistor, and the total resistance is 11K Ω. It should be noted that, the resistances of the first resistor R1, the second resistor R2, the seventh resistor R7, the third resistor R3, the fourth resistor R4 and the eighth resistor R8 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.
Fig. 3a is a schematic structural diagram of a first switch unit provided in an embodiment of the present invention. Fig. 3b is a schematic structural diagram of a second switch unit provided in the embodiment of the present invention.
As shown in fig. 3a, the first switch subunit includes: the first coupling switch U1, the fifth resistor R5 and the first power tube Q1; a first end of the first coupling switch U1 is connected to the first resistor R1, and a second end of the first coupling switch U1 is connected to the second resistor R2; the third end of the first coupling switch U1 is externally connected with a power supply module through a fifth resistor R5; the fourth end of the first coupling switch U1 is connected with the first end of the first power tube Q1; the second end of the first power tube Q2 is connected with the control module, and the third end of the first power tube Q1 is grounded.
As shown in fig. 3b, the second switch subunit includes: the second coupling switch U2, a sixth resistor R6 and a second power tube Q2; a first end of the second coupling switch U2 is connected to the third resistor R3, and a second end of the second coupling switch U2 is connected to the fourth resistor R4; the third end of the second coupling switch U2 is externally connected with the power supply module through a sixth resistor R6; the fourth end of the second coupling switch U2 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 Q3 is grounded.
The first coupling switch U1 and the second coupling switch U2 respectively include a control side diode and an output side MOSFET two-part structure. The first end of a fifth resistor R5 is connected with a 5V power supply inside the BMS, the second end of the fifth resistor R5 is connected with the anode of a diode at the control side of the first coupling switch U1, the cathode of the diode is connected with the collector of the first power tube Q1, the base of the first power tube Q1 is connected with the GPIO1 port of the MCU, the emitter of the first power tube Q1 is connected with the low-voltage ground inside the BMS, the first end of the first resistor R1 is connected with the first pin 1, the second end of the first resistor R1 is connected with the pin 6 of the first coupling switch U1, the first end of the second resistor R2 is connected with the pin 4 of the first coupling switch U1, and the second end of the second resistor R2 is connected with the OUT1 port.
The first end of a sixth resistor R6 is connected with a 5V power supply in the BMS, the second end of the sixth resistor R6 is connected with the anode of a diode at the control side of the second coupling switch U2, the cathode of the diode is connected with the collector of the second power tube Q2, the base of the second power tube Q2 is connected with the GPIO2 port of the MCU, the emitter of the second power tube Q2 is connected with the low-voltage ground in the BMS, the first end of a third resistor R3 is connected with the second pin 2, the second end of the third resistor R3 is connected with the pin 6 of the second coupling switch U2, the first end of a fourth resistor R4 is connected with the pin 4 of the second coupling switch U2, and the second end of the fourth resistor R4 is connected with the OUT2 port.
When the BMS is powered up and initialized, the MCU pins GPIO1 and GPIO2 are in a low state, and at this time, the NPN transistors Q1 and Q2 are in an off state, when the BMS performs insulation resistance detection, the GPIO1 and GPIO2 are sequentially set to a high level, when the GPIO1 or GPIO2 is set to a high level, the corresponding transistor is in an on state, for the upper arm circuit, in the low voltage control loop in the first coupling switch U1, the conduction current ION1 is mainly determined by a voltage of 5V, a series resistor R7, a diode conduction voltage drop in the first coupling switch U1, and a conduction voltage drop of the transistor Q1, for the lower arm circuit, in the low voltage control loop in the second coupling switch U2, the conduction current ION2 is mainly determined by a voltage of 5V, a diode conduction voltage drop in the resistor R8, a diode conduction voltage drop in the second coupling switch U2, and a conduction voltage drop of the transistor Q2.
In this embodiment, the first coupling switch U1 and the second coupling switch U2 are opto-coupler switches (Photo relay) with a number of channels, AQV258HAX _ C88, and the first power transistor Q1 and the second power transistor Q2 are transistors with a number of channels, 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. 4a is a schematic structural diagram of a first isolation subunit provided in an embodiment of the present invention; fig. 4b is a schematic structural diagram of a second isolation subunit provided in an embodiment of the present invention; as shown in fig. 4a and 4b, the first isolation subunit includes: ninth resistor R9 and first amplifier 41, the second isolation subunit comprising: a tenth resistor R10 and a second amplifier 42.
The first terminal 3 of the first amplifier 41 is connected to the second resistor R2 (see fig. 2) through a ninth resistor R9, the second terminal 2 of the first amplifier 41 is connected to the third terminal 1 of the first amplifier 41, and the third terminal 41 of the first amplifier is connected to the analog-to-digital conversion module 205 (see fig. 2); the first terminal 5 of the second amplifier 42 is connected to the fourth resistor R4 (see fig. 2) through the tenth resistor R5, the second terminal 6 of the second amplifier 42 is connected to the third terminal 7 of the second amplifier 42, and the third terminal 7 of the second amplifier 42 is connected to the analog-to-digital conversion module 205 (see fig. 2).
The first terminal of the ninth resistor R9 is connected to the OUT1 port in fig. 3a, and the second terminal of the ninth resistor R9 is connected to the 3-pin of the first operational amplifier 41. The first operational amplifier 41 has pins 2 and 1 connected to form a follower circuit of the upper arm. The first terminal of the tenth resistor R10 is connected to the OUT2 port in fig. 3b, and the second terminal of the tenth resistor R10 is connected to pin 3 of the second operational amplifier 42. And the pin 2 and the pin 1 of the second operational amplifier 42 are connected to form a following circuit of the lower bridge arm.
Fig. 5 is a schematic diagram of an operational amplifier according to an embodiment of the present invention. As shown in fig. 5, the operational amplifier is AD8629, and the operational amplifier includes two identical operational amplifier channels, wherein the resistance of the ninth resistor R9 and the tenth resistor R10 is 1K Ω.
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; the single-ended voltage signals VOUT1 and VOUT2 output by the operational amplifier are connected to analog input ports AIN0 and AIN1 of the high-precision analog-to-digital conversion chip 61, are converted inside the high-precision analog-to-digital conversion chip 61, and are in data communication with the upper computer 62 through the SPI. In this example, the output port VOUT1 of the operational amplifier is connected to the analog input pin AIN0 of the high-precision analog-to-digital conversion chip 61, and the output port VOUT2 of the operational amplifier is connected to the analog input pin AIN1 of the high-precision analog-to-digital conversion chip 61. The analog-to-digital conversion chip 61 has a total of 4 analog input channels and communicates with the upper computer 62 through the SPI. The upper computer 62 adopts an MPC5644 chip. The resolution of the high-precision analog-to-digital conversion chip 61 is 16 bits, and the resolution of the built-in analog-to-digital conversion unit of the upper computer 62 is 12 bits. In an actual circuit, the sampling precision of the upper computer 62 is plus or minus 20mV, and the sampling precision of the high-precision analog-to-digital conversion chip 61 is plus or minus 3.5mV, so the detection precision of the insulation resistance can be effectively improved through the high-precision analog-to-digital conversion chip 61.
The detection steps of the insulation resistance provided in the embodiment are as follows: through the control of the upper computer, the GPIO1 is set to be high level, and the GPIO2 is set to be low level. The delay is 100ms, and the upper computer reads the voltage value of the positive electrode and marks the voltage value as X. After the positive voltage value is read, the GPIO1 is set to be low level and the GPIO2 is set to be low level through upper computer control. And delaying for 100ms, and reading the voltage value of the negative electrode by the upper computer and recording as Y. After the reading of the voltage value of the negative electrode is finished, the GPIO1 is set to be at a low level and the GPIO2 is set to be at a low level through the control of the upper computer.
Wherein, R1+ R2 is 1100000 Ω, R5 is 11000 Ω, R3+ R4 is 1100000 Ω, R6 is 11000 Ω, VCC is 5V, and V1 is the total voltage of the power battery.
Let K1 ═ V1 × R5 — X × (R1+ R2+ R5), K2 ═ X, K3 ═ R1+ R2+ R5) × X, K4 ═ V1+ Y- (VCC-Y) × (R3+ R4)/R6, K5 ═ VCC-Y) × (R3+ R4)/R6-Y, and K6 ═ VCC-Y)/R6.
The above-described combined calculation yields positive insulation resistance RP ═ K4/(K5/RN + K6), and negative insulation resistance RN ═ K1-K3 × K5/K4)/(K2+ K3 × K6/K4.
On the basis of the above embodiment, the embodiment of the present invention further provides an apparatus, which includes any one of the above embodiments of the detection circuit of the insulation resistor.
The embodiment of the utility model provides an equipment can include the utility model discloses the detection circuitry of the insulation resistance that the 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. An insulation resistance detection circuit, comprising: the device comprises a first detection module, a second detection module, an analog-to-digital conversion module and a control module;
the first detection module is externally connected with the anode of the power battery, is respectively connected with the analog-to-digital conversion module and the control module, and is used for acquiring an anode analog voltage signal of the power battery after receiving a first detection instruction sent by the control module and outputting the anode analog voltage signal to the analog-to-digital conversion module;
the second detection module is externally connected with the cathode of the power battery, is respectively connected with the analog-to-digital conversion module and the control module, and is used for acquiring a cathode analog voltage signal of the power battery after receiving a second detection instruction sent by the control module and outputting the cathode analog voltage signal to the analog-to-digital conversion module;
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 anode analog voltage signal into an anode digital voltage signal; converting the negative analog voltage signal into a negative digital voltage signal;
and the control module is used for determining the insulation resistance of the power battery according to the positive digital voltage signal and the negative digital voltage signal.
2. The circuit of claim 1, wherein the first detection module comprises: first contact pin, first detecting element and first isolation element, the second detection module includes: the second pin, the second detection unit and the second isolation unit; wherein the content of the first and second substances,
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 detection unit; the second end of the first detection unit is connected with the analog-to-digital conversion module through the first isolation unit, and the third end of the first detection unit is 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 detection unit; the second end of the second detection unit is connected with the analog-to-digital conversion module through the second isolation unit, and the third end of the second detection unit is connected with the control module.
3. The circuit of claim 2, wherein the first detection unit comprises: a first resistor, a second resistor, and a first switch subunit, wherein,
the first contact pin is connected with the first end of the first switch subunit through the first resistor, the second end of the first switch subunit is connected with the first isolation unit through the second resistor, and the third end of the first switch subunit is connected with the control module.
4. The circuit of claim 2, wherein the second detection unit comprises: a third resistor, a fourth resistor, and a second switch subunit, wherein,
the second contact pin passes through the third resistance with the first end of second switch subunit is connected, the second end of second switch subunit passes through the fourth resistance with the second isolation unit is connected, the third end of second switch subunit with control module connects.
5. The circuit of claim 3, wherein the first switch subunit comprises: the first coupling switch, the fifth 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 the first resistor, and a second end of the first coupling switch is connected with the second resistor; the third end of the first coupling switch is externally connected with a power supply module through the fifth 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.
6. The circuit of claim 4, wherein the second switch subunit comprises: the second coupling switch, the sixth 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 the third resistor, and a second end of the second coupling switch is connected with the fourth resistor; the third end of the second coupling switch is externally connected with a power supply module through the sixth 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 any of claims 5 or 6, wherein the first isolation unit comprises: seventh resistance and first isolation subunit, second isolation unit includes: an eighth resistor and a second isolation subunit; wherein the content of the first and second substances,
the first end of the first isolation subunit is grounded through the seventh resistor, the first end of the first isolation subunit is connected with the second resistor, and the second end of the first isolation subunit is connected with the analog-to-digital conversion module;
the first end of the second isolation subunit is externally connected with a power supply module through the eighth resistor, the first end of the second isolation subunit is connected with the fourth resistor, and the second end of the second isolation subunit is connected with the analog-to-digital conversion module.
8. The circuit of claim 7, wherein the first isolation subunit comprises: ninth resistance and first amplifier, the second isolation subunit includes: a tenth resistor and a second amplifier; wherein the content of the first and second substances,
the first end of the first amplifier is connected with the second resistor through a ninth resistor, the second end of the first amplifier is connected with the third end of the first amplifier, and the third end of the first amplifier is connected with the analog-to-digital conversion module;
the first end of the second amplifier is connected with the fourth resistor through a tenth resistor, the second end of the second amplifier is connected with the third end of the second amplifier, and the third end of the second amplifier is connected with the analog-to-digital conversion module.
9. The circuit of claim 8, wherein the resolution of the analog-to-digital conversion module 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 detection circuit of the insulation resistance according to any of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921127435.7U CN211043618U (en) | 2019-07-17 | 2019-07-17 | Detection circuit and equipment for insulation resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921127435.7U CN211043618U (en) | 2019-07-17 | 2019-07-17 | Detection circuit and equipment for insulation resistance |
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| Publication Number | Publication Date |
|---|---|
| CN211043618U true CN211043618U (en) | 2020-07-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921127435.7U Active CN211043618U (en) | 2019-07-17 | 2019-07-17 | Detection circuit and equipment for insulation resistance |
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| CN (1) | CN211043618U (en) |
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