CN113933575A - Sampling device, diagnosis method and vehicle - Google Patents

Sampling device, diagnosis method and vehicle Download PDF

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Publication number
CN113933575A
CN113933575A CN202111193465.XA CN202111193465A CN113933575A CN 113933575 A CN113933575 A CN 113933575A CN 202111193465 A CN202111193465 A CN 202111193465A CN 113933575 A CN113933575 A CN 113933575A
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China
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voltage
switch
sampling point
sampling
negative
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CN202111193465.XA
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CN113933575B (en
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邓磊
谢哲锋
郭洪江
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Guangzhou Xiaopeng Motors Technology Co Ltd
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Guangzhou Xiaopeng Motors Technology Co Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • G01R19/2503—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques for measuring voltage only, e.g. digital volt meters (DVM's)
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • G01R19/2506—Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values ; Details concerning sampling, digitizing or waveform capturing
    • G01R19/2509—Details concerning sampling, digitizing or waveform capturing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/12—Analogue/digital converters
    • H03M1/124—Sampling or signal conditioning arrangements specially adapted for A/D converters
    • H03M1/1245—Details of sampling arrangements or methods
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries

Abstract

The invention discloses a sampling device, a diagnosis method and a vehicle, wherein the sampling device comprises a first sampling circuit and a second sampling circuit; the first sampling circuit respectively samples earth voltages to earth of the negative electrode and the positive electrode of the battery pack through a first sampling point and a second sampling point; the second sampling circuit respectively samples the earth voltage of the negative electrode and the positive electrode of the motor through a third sampling point and a fourth sampling point, and respectively samples the earth voltage of the negative electrode and the positive electrode of the charging pile through a fifth sampling point and a sixth sampling point; and diagnosing the main positive switch, the main negative switch, the pre-charging switch, the quick-charging positive switch and the quick-charging negative switch according to the voltage acquisition result. The sampling device, the diagnosis method and the vehicle have the advantages that resistance loops are not arranged at two ends of the switch, high-voltage safety risks are avoided for power distribution, and the cost is low.

Description

Sampling device, diagnosis method and vehicle
Technical Field
The invention relates to the technical field of electric automobiles, in particular to a sampling device, a diagnosis method and a vehicle.
Background
New energy automobiles are rapidly popularized in the world due to clean and environment-friendly power sources and excellent conversion efficiency. The battery distribution of the new energy automobile is to distribute the high voltage output by the storage battery pack to a load through a relay for use. In order to realize the control of high-voltage energy, the new energy automobile needs to sample the high voltage of power distribution through a high-voltage sampling circuit.
The existing high-voltage sampling circuit generally has two schemes for sampling multi-path high voltage, wherein one scheme is that one set of isolation sampling circuit is independently configured for each high-voltage sampling point for sampling, the other scheme is that a plurality of high-voltage sampling points share one set of isolation sampling circuit, and a sampling loop is switched through a high-voltage switch, so that the situation that the two sides of a relay form a connecting loop to threaten electrical safety can be avoided.
The first scheme needs to be provided with a plurality of sets of isolation sampling circuits, the circuit is complex and high in cost, the second scheme needs to be provided with a high-voltage switch to switch the sampling circuits, the control is complex, and the electrical safety is easily threatened when the high-voltage switch is damaged. Therefore, the existing high-voltage sampling circuit is complex in composition and control and relatively high in cost, and the high-voltage sampling circuit forms high-resistance loops on two sides of the relay, so that the electrical safety of high-voltage power distribution is threatened easily.
Disclosure of Invention
The invention aims to provide a sampling device, a diagnosis method and a vehicle, which can improve the risk of the existing sampling device on high-voltage safety and can reduce the high-voltage sampling cost.
The invention provides a sampling device, which comprises a first sampling circuit and a second sampling circuit; the first sampling circuit comprises a first sampling point, a second sampling point and a first grounding point; the first sampling point is connected with the negative electrode of the battery pack, the first end of the main negative switch and the first end of the quick charge negative switch and is used for sampling the grounding voltage of the negative electrode of the battery pack; the second sampling point is connected with the positive electrode of the battery pack, the first end of the main positive switch, the first end of the pre-charging switch and the first end of the quick charging positive switch and is used for sampling the grounding voltage of the positive electrode of the battery pack; the first ground point is grounded; the second sampling circuit comprises a third sampling point, a fourth sampling point, a fifth sampling point, a sixth sampling point and a second grounding point; the third sampling point is connected with the negative electrode of the motor and the second end of the main negative switch and is used for sampling the earth voltage of the negative electrode of the motor; the fourth sampling point is connected with both the second end of the main positive switch and the positive electrode of the motor, and is also connected with the second end of the pre-charging switch through a pre-charging resistor, and is used for sampling the earth voltage of the positive electrode of the motor; the fifth sampling point is connected with the second end of the quick charge negative switch and the negative electrode of the charging pile and is used for sampling the voltage of the negative electrode of the charging pile to earth; the sixth sampling point is connected with the second end of the quick charging positive switch and the anode of the charging pile and is used for sampling the earth voltage of the anode of the charging pile to the ground; the second ground point is grounded.
In one embodiment, the master negative switch, the master positive switch, the pre-charging switch, the fast-charging negative switch and the fast-charging positive switch are all relay switches.
In one embodiment, the second sampling circuit further includes an ADC sampling circuit, the ADC sampling circuit includes a first receiving terminal, a second receiving terminal, a third receiving terminal, a fourth receiving terminal, and a ground terminal, the first receiving terminal of the ADC sampling circuit is connected to the third sampling point, the second receiving terminal of the ADC sampling circuit is connected to the fourth sampling point, the third receiving terminal of the ADC sampling circuit is connected to the fifth sampling point, the fourth receiving terminal of the ADC sampling circuit is connected to the sixth sampling point, and the ground terminal of the ADC sampling circuit is connected to the second ground point.
The invention also discloses a diagnostic method, comprising: voltage collection is carried out on a first sampling point, a second sampling point, a third sampling point, a fourth sampling point, a fifth sampling point and a sixth sampling point in a sampling device, wherein the first sampling point is connected with the negative electrode of a battery pack, the first end of a master negative switch and the first end of a quick charge negative switch and is used for sampling the grounding voltage of the negative electrode of the battery pack; the second sampling point is connected with the positive electrode of the battery pack, the first end of the main positive switch, the first end of the pre-charging switch and the first end of the quick charging positive switch and is used for sampling the grounding voltage of the positive electrode of the battery pack; the third sampling point is connected with the negative electrode of the motor and the second end of the main negative switch and is used for sampling the earth voltage of the negative electrode of the motor; the fourth sampling point is connected with both the second end of the main positive switch and the positive electrode of the motor, and is also connected with the second end of the pre-charging switch through a pre-charging resistor, and is used for sampling the earth voltage of the positive electrode of the motor; the fifth sampling point is connected with the second end of the quick charge negative switch and the negative electrode of the charging pile and is used for sampling the voltage of the negative electrode of the charging pile to earth; the sixth sampling point is connected with the second end of the quick charging positive switch and the anode of the charging pile and is used for sampling the earth voltage of the anode of the charging pile to the ground; and diagnosing the total positive switch, the total negative switch, the pre-charging switch, the quick charging positive switch and the quick charging negative switch according to a voltage acquisition result.
In one embodiment, the diagnosing the total positive switch, the total negative switch, the pre-charge switch, the fast charge positive switch, and the fast charge negative switch according to the voltage collecting result includes: when the battery pack discharges, closing the total negative switch, and judging that the total negative switch has a closing fault when detecting that the absolute value of the voltage of the third sampling point is not greater than a first voltage threshold value in a first time or when detecting that the absolute value of the voltage difference between the voltage of the first sampling point and the voltage of the third sampling point is not less than a second voltage threshold value in a second time; when the absolute value of the voltage of the third sampling point is detected to be greater than the first voltage threshold value within the first time, or the absolute value of the voltage difference between the voltage of the first sampling point and the voltage of the third sampling point is detected to be less than the second voltage threshold value within the second time, determining that the total negative switch is normally closed, wherein the first voltage threshold value and the second voltage threshold value are both greater than zero; after the total negative switch is judged to be normally closed, closing the pre-charging switch, if the absolute value of the difference value between the voltage difference between the voltage of the second sampling point and the voltage of the first sampling point and the difference value between the voltage of the fourth sampling point and the voltage of the third sampling point is detected to be smaller than a fifth voltage threshold value in third time, judging that the pre-charging switch is normally closed, otherwise, judging that the pre-charging switch has a closing fault, wherein the fifth voltage threshold value is larger than zero; or when the battery pack discharges, closing the pre-charging switch, if the absolute value of the voltage of the fourth sampling point is detected to be greater than a third voltage threshold value in the first time, or the absolute value of the voltage difference between the voltage of the second sampling point and the voltage of the fourth sampling point is detected to be less than a fourth voltage threshold value in the second time, determining that the pre-charging switch is normally closed, otherwise, determining that the pre-charging switch has a closing fault; after the pre-charging switch is judged to be normally closed, closing the total negative switch, if the absolute value of the difference value between the voltage difference between the voltage of the second sampling point and the voltage of the first sampling point and the difference value between the voltage of the fourth sampling point and the voltage of the third sampling point is detected to be smaller than a fifth voltage threshold value within the third time, judging that the total negative switch is normally closed, otherwise, judging that the total negative switch has a closing fault, wherein the third voltage threshold value and the fourth voltage threshold value are both larger than zero; and after the total negative switch and the pre-charging switch are judged to be normally closed, closing the total positive switch, if the absolute value of the difference value between the voltage difference between the voltage of the second sampling point and the voltage of the first sampling point and the voltage difference between the voltage of the fourth sampling point and the voltage of the third sampling point is detected to be less than a sixth voltage threshold value in fourth time, judging that the total positive switch is normally closed, otherwise, judging that the total positive switch has a closing fault, wherein the sixth voltage threshold value is more than zero.
In one embodiment, the diagnosing the total positive switch, the total negative switch, the pre-charge switch, the fast charge positive switch, and the fast charge negative switch according to the voltage collecting result includes: when the battery pack stops discharging, the total positive switch is disconnected, and when the absolute value of the difference value between the voltage difference of the voltage of the second sampling point and the voltage of the first sampling point and the difference value between the voltage of the fourth sampling point and the voltage of the third sampling point is not larger than a seventh voltage threshold value within fifth time, the total positive switch is judged to have a disconnection fault; when detecting that the absolute value of the difference value between the voltage difference between the voltage of the second sampling point and the voltage of the first sampling point and the voltage difference between the voltage of the fourth sampling point and the voltage of the third sampling point is greater than a seventh voltage threshold value within the fifth time, determining that the total positive switch is normally turned off, wherein the seventh voltage threshold value is greater than zero; after the total positive switch is judged to be normally switched off, switching off the total negative switch, if the absolute value of the voltage of the third sampling point is detected to be smaller than an eighth voltage threshold value in sixth time, or the absolute value of the voltage difference between the voltage of the first sampling point and the voltage of the third sampling point is detected to be larger than a ninth voltage threshold value in seventh time, judging that the total negative switch is normally switched off, otherwise, judging that the total negative switch has a switching-off fault, wherein the eighth voltage threshold value and the ninth voltage threshold value are both larger than zero; or when the battery pack stops discharging, disconnecting the total negative switch, if the absolute value of the difference between the voltage of the second sampling point and the voltage of the first sampling point and the difference between the voltage of the fourth sampling point and the voltage of the third sampling point is detected to be greater than the seventh voltage threshold value within the fifth time, judging that the total negative switch is normally disconnected, otherwise, judging that the total negative switch has a disconnection fault; and after the total negative switch is judged to be normally switched off, switching off the total positive switch, if the absolute value of the voltage of the fourth sampling point is detected to be smaller than a tenth voltage threshold value in the sixth time, or the absolute value of the voltage difference between the voltage of the second sampling point and the voltage of the fourth sampling point is detected to be larger than an eleventh voltage threshold value in the seventh time, judging that the total positive switch is normally switched off, otherwise, judging that the total positive switch has a switching-off fault, wherein the tenth voltage threshold value and the eleventh voltage threshold value are both larger than zero.
In one embodiment, the diagnosing the total positive switch, the total negative switch, the pre-charge switch, the fast charge positive switch, and the fast charge negative switch according to the voltage collecting result includes:
when the battery pack is charged, closing the quick charge negative switch, and judging that the quick charge negative switch has a closing fault when detecting that the absolute value of the voltage of the fifth sampling point is not more than a twelfth voltage threshold value in eighth time or detecting that the absolute value of the voltage difference between the voltage of the first sampling point and the voltage of the fifth sampling point is not less than a thirteenth voltage threshold value in ninth time; when the absolute value of the voltage of the fifth sampling point is detected to be greater than the twelfth voltage threshold value within the eighth time, or the absolute value of the voltage difference between the voltage of the first sampling point and the voltage of the fifth sampling point is detected to be less than the thirteenth voltage threshold value within the ninth time, determining that the quick-charging negative switch is normally closed, wherein the twelfth voltage threshold value and the thirteenth voltage threshold value are both greater than zero; after the quick charge negative switch is judged to be normally closed, closing the quick charge positive switch, if the absolute value of the difference value between the voltage difference between the voltage of the second sampling point and the voltage of the first sampling point and the difference value between the voltage of the sixth sampling point and the voltage of the fifth sampling point is detected to be smaller than a sixteenth voltage threshold value within tenth time, judging that the quick charge positive switch is normally closed, otherwise, judging that the quick charge positive switch has a closing fault, wherein the sixteenth voltage threshold value is larger than zero; or when the battery pack is charged, closing the quick charge positive switch, if the absolute value of the voltage of the sixth sampling point is detected to be greater than a fourteenth voltage threshold value in the eighth time, or the absolute value of the voltage difference between the voltage of the second sampling point and the voltage of the sixth sampling point is detected to be less than a fifteenth voltage threshold value in the ninth time, determining that the quick charge positive switch is normally closed, otherwise, determining that the quick charge positive switch has a closing fault; after the fast charging positive switch is judged to be normally closed, the fast charging negative switch is closed, if the absolute value of the difference value between the voltage difference between the voltage of the second sampling point and the voltage of the first sampling point and the difference value between the voltage of the sixth sampling point and the voltage of the fifth sampling point is detected to be smaller than the sixteenth voltage threshold value within the tenth time, the fast charging negative switch is judged to be normally closed, otherwise, the fast charging negative switch is judged to have a closing fault, wherein the fourteenth voltage threshold value and the fifteenth voltage threshold value are both larger than zero.
In one embodiment, the diagnosing the total positive switch, the total negative switch, the pre-charge switch, the fast charge positive switch, and the fast charge negative switch according to the voltage collecting result includes: when the battery pack stops charging, the quick charge positive switch is disconnected, and when the fact that the absolute value of the difference value between the voltage difference of the voltage of the second sampling point and the voltage of the first sampling point and the difference value between the voltage of the sixth sampling point and the voltage of the fifth sampling point is not larger than a seventeenth voltage threshold value is detected within eleventh time, it is judged that the quick charge positive switch has a disconnection fault; when detecting that the absolute value of the difference value between the voltage difference between the voltage at the second sampling point and the voltage at the first sampling point and the voltage difference between the voltage at the sixth sampling point and the voltage at the fifth sampling point is greater than a seventeenth voltage threshold value within the eleventh time, determining that the fast charge positive switch is normally turned off, wherein the seventeenth voltage threshold value is greater than zero; after the fast charging positive switch is judged to be normally disconnected, disconnecting the fast charging negative switch, if the absolute value of the voltage of the fifth sampling point is detected to be smaller than an eighteenth voltage threshold value in the twelfth time, or the absolute value of the voltage difference between the voltage of the first sampling point and the voltage of the fifth sampling point is detected to be larger than a nineteenth voltage threshold value in the thirteenth time, judging that the fast charging negative switch is normally disconnected, otherwise, judging that the fast charging negative switch has a disconnection fault, wherein the eighteenth voltage threshold value and the nineteenth voltage threshold value are both larger than zero; or when the battery pack stops charging, disconnecting the quick charge negative switch, if the absolute value of the difference between the voltage of the second sampling point and the voltage of the first sampling point and the difference between the voltage of the sixth sampling point and the voltage of the fifth sampling point is detected to be greater than the seventeenth voltage threshold value within the eleventh time, judging that the quick charge negative switch is normally disconnected, otherwise, judging that the quick charge negative switch has a disconnection fault; after the quick charge negative switch is judged to be normally disconnected, disconnecting the quick charge positive switch, if the absolute value of the voltage of the sixth sampling point is detected to be smaller than a twentieth voltage threshold value in the twelfth time, or the absolute value of the voltage difference between the voltage of the second sampling point and the voltage of the sixth sampling point is detected to be larger than a twenty-first voltage threshold value in the thirteenth time, judging that the quick charge positive switch is normally disconnected, otherwise, judging that the quick charge positive switch has a disconnection fault; the twentieth voltage threshold and the twenty-first voltage threshold are both greater than zero.
In one embodiment, the diagnosing the total positive switch, the total negative switch, the pre-charge switch, the fast charge positive switch, and the fast charge negative switch according to the voltage collecting result includes: in a fourteenth time, disconnecting the total negative switch, the total positive switch, the pre-charging switch, the quick-charging negative switch and the quick-charging positive switch, if the absolute value of the voltage of the third sampling point is detected to be smaller than a twenty-second voltage threshold value, judging that the total negative switch is normally disconnected, otherwise, judging that the total negative switch has a disconnection fault; when the absolute value of the voltage of the fourth sampling point is smaller than a twenty-third voltage threshold value, judging that the main positive switch or the pre-charging switch is normally disconnected, otherwise, judging that the main positive switch or the pre-charging switch has a disconnection fault; when the absolute value of the voltage of the fifth sampling point is smaller than a twenty-fourth voltage threshold value, judging that the quick charge negative switch is normally disconnected, otherwise, judging that the quick charge negative switch has a disconnection fault; when the absolute value of the voltage of the sixth sampling point is smaller than a twenty-fifth voltage threshold value, judging that the quick charge positive switch is normally disconnected, otherwise, judging that the quick charge positive switch has a disconnection fault; the twenty-second voltage threshold, the twenty-third voltage threshold, the twenty-fourth voltage threshold, and the twenty-fifth voltage threshold are all greater than zero.
The invention also discloses a vehicle comprising the sampling device.
According to the sampling device, the diagnosis method and the vehicle provided by the embodiment of the invention, resistance loops are not arranged at two ends of the switch, the sampling circuit has no high-voltage safety risk to power distribution, the structure is simple, the cost is low, the switch state can be actively detected, and the safety and the reliability of high-voltage power distribution can be improved.
Drawings
Fig. 1 is a schematic diagram illustrating a structure and a connection relationship of a sampling device according to an embodiment of the present invention.
FIG. 2 is a schematic diagram of a diagnostic method according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a diagnostic method during battery discharge according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of a diagnostic method when the battery pack stops discharging according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of a diagnosis method during battery pack charging according to an embodiment of the present invention.
Fig. 6 is a schematic diagram of a diagnostic method when the battery pack stops charging according to an embodiment of the present invention.
Detailed Description
To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, features and effects of the present invention will be made with reference to the accompanying drawings and examples.
Fig. 1 is a schematic diagram illustrating a structure and a connection relationship of a sampling device according to an embodiment of the present invention. Referring to fig. 1, in the present embodiment, a sampling apparatus includes a first sampling circuit and a second sampling circuit.
The first sampling circuit includes a first sampling point a1, a second sampling point a2, and a first ground point G1. The first sampling point A1 is connected with the negative electrode of the battery pack, the first end of the master negative switch S2 and the first end of the quick charge negative switch S5 and is used for sampling the grounding voltage of the negative electrode of the battery pack; the second sampling point A2 is connected with the positive electrode of the battery pack, the first end of the master positive switch S1, the first end of the pre-charging switch S3 and the first end of the quick-charging positive switch S4, and is used for sampling the grounding voltage of the positive electrode of the battery pack; the first grounding point G1 is grounded. The second sampling circuit includes a third sampling point B1, a fourth sampling point B2, a fifth sampling point C1, a sixth sampling point C2, and a second ground point G2; the third sampling point B1 is connected with the negative pole of the motor and the second end of the master negative switch S2 and is used for sampling the earth voltage of the negative pole of the motor; the fourth sampling point B2 is connected to both the second terminal of the main positive switch S1 and the positive electrode of the motor, and is also connected to the second terminal of the pre-charge switch S3 through a pre-charge resistor R, for sampling the earth voltage of the positive electrode of the motor; the fifth sampling point C1 is connected with the second end of the quick charge negative switch S5 and the negative electrode of the charging pile and is used for sampling the voltage of the negative electrode of the charging pile to earth; the sixth sampling point C2 is connected with the second end of the quick charging positive switch S4 and the positive electrode of the charging pile and is used for sampling the voltage of the positive electrode of the charging pile to earth; the second grounding point G2 is grounded.
In one embodiment, the total negative switch S2, the total positive switch S1, the pre-charge switch S3, the fast-charge negative switch S5 and the fast-charge positive switch S4 may be relay switches, but the embodiment is not limited thereto, and one or more combinations of relay switches, electronic switches, contactors and air switches may be used as the switches.
In an embodiment, the second sampling circuit may further include an ADC sampling circuit, the ADC sampling circuit may include a first receiving terminal, a second receiving terminal, a third receiving terminal, a fourth receiving terminal, and a ground terminal, the first receiving terminal of the ADC sampling circuit is connected to the third sampling point B1, the second receiving terminal of the ADC sampling circuit is connected to the fourth sampling point B2, the third receiving terminal of the ADC sampling circuit is connected to the fifth sampling point C1, the fourth receiving terminal of the ADC sampling circuit is connected to the sixth sampling point C2, and the ground terminal of the ADC sampling circuit is connected to the second ground point G2. Accordingly, the voltages of the third sampling point B1 to the sixth sampling point C2 may be collected by the ADC sampling circuit in the second sampling circuit.
Specifically, as shown in fig. 1, the high-voltage distribution of the battery pack in the present embodiment is based on a grounded ground, and the ground insulation state thereof may be equivalent to: the positive pole of group battery passes through insulation resistance RPA ground connection, and insulation resistance RNA ground connection is passed through to the negative pole of group battery, and insulation resistance RPB ground connection is passed through to the positive pole of motor, and insulation resistance RNB ground connection is passed through to the negative pole of motor, and insulation resistance RNC ground connection is passed through to the negative pole of filling electric pile, and insulation resistance RPC ground connection is passed through to the positive pole of filling electric pile. In this embodiment, the sampling device includes a first sampling circuit and a second sampling circuit, the first sampling circuit is used for sampling the high voltage on the battery pack side, the first sampling circuit samples the voltage of the negative pole of the battery pack to the ground via a first sampling point a1, the second sampling point a2 samples the voltage of the positive pole of the battery pack to the ground, and the first sampling circuit samples the voltage of the positive pole of the battery pack to the ground according to the first sampling pointThe voltage difference between the voltage at the point a1 and the voltage at the second sampling point a2 can obtain the voltage difference between the two sides of the battery pack, i.e., the battery pack voltage UA(ii) a The second sampling circuit is used for sampling high voltage of the motor side and the charging pile side, the second sampling circuit samples the grounding voltage of the negative electrode of the motor through a third sampling point B1, the grounding voltage of the positive electrode of the motor is sampled through a fourth sampling point B2, and the voltage difference of two sides of the motor, namely the motor voltage U, can be obtained according to the voltage difference of the voltage of the third sampling point B1 and the voltage of the fourth sampling point B2BThe fifth sampling point C1 collects the second end-to-ground voltage of the fast charge negative switch S5, and the sixth sampling point C2 collects the second end-to-ground voltage of the fast charge positive switch S4, so that the fifth sampling point C1 can be connected to the negative electrode of the battery pack through the conducted fast charge negative switch S5, and the sixth sampling point C2 can be connected to the positive electrode of the battery pack through the conducted fast charge positive switch S4, so that the battery voltage U at the charging post side can be obtained according to the voltage difference between the voltage of the fifth sampling point C1 and the voltage of the sixth sampling point C2C。
Meanwhile, as shown in fig. 1, the battery pack, the insulation resistor RPA, and the insulation resistor RNA form a voltage loop, and the connection line between the insulation resistor RPA and the insulation resistor RNA is grounded, so that the voltage of the negative electrode of the battery pack is a negative voltage, the voltage of the positive electrode of the battery pack is a positive voltage, and the difference between the positive voltage and the negative voltage is the battery voltage. Therefore, the voltage at the first sampling point a1 of the first sampling circuit is a negative voltage, the voltage at the second sampling point a2 of the first sampling circuit is a positive voltage, and the battery pack voltage UA can be obtained according to the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a 1.
Meanwhile, the present embodiment can determine whether each switch is working normally through the voltage values of each sampling point when the total negative switch S2, the precharge switch S3, the total positive switch S1, the fast charging negative switch S5 and the fast charging positive switch S4 are turned on and off. The total negative switch S2, the pre-charging switch S3, the total positive switch S1, the fast charging negative switch S5 and the fast charging positive switch S4 are closed, so that corresponding sampling points are connected with the positive electrode or the negative electrode of the battery pack through the turned-on switches to receive corresponding positive voltage or negative voltage, and the total negative switch S2, the pre-charging switch S3, the total positive switch S1, the fast charging negative switch S5 and the fast charging positive switch S4 are opened, so that the corresponding sampling points are grounded through corresponding insulation resistors to enable the sampling voltage to be zero, and therefore whether the closing or opening operation of the corresponding switches is normally executed can be judged according to the earth-earth voltage of the corresponding sampling points. For example, the total negative switch S2 is closed, and if the absolute value of the voltage sampled at the third sampling point B1 is smaller than the corresponding voltage threshold, that is, is close to zero, it may be determined that a closed fault occurs in the total negative switch S2, where the closed fault makes the third sampling point B1 unable to receive the negative voltage of the negative electrode of the battery pack through the total negative switch S2, and the third sampling point B1 is grounded through the insulation resistor RNB, so that the voltage sampled at the third sampling point B1 is close to zero. Meanwhile, whether the closing or opening operation of the corresponding switch is normally performed may also be determined according to the difference between the voltages of the corresponding sampling points on the two ends of the switch, for example, the difference between the first sampling point a1 and the third sampling point B1 on the two ends of the total negative switch S2 is close to zero, the total negative switch S2 may be determined to be in a closed state, and then it may be determined that the closing operation performed by the total negative switch S2 is normally performed or the opening operation is abnormally performed, that is, an opening fault occurs. In addition, in the present embodiment, the operating states of discharging, stopping discharging, charging and stopping charging of the battery pack can be further determined through the voltage values of the sampling points of the total negative switch S2, the pre-charging switch S3, the total positive switch S1, the fast charging negative switch S5 and the fast charging positive switch S4 when being closed and opened, so as to prevent the switch from being in a closed or opened fault.
Since the first sampling point a1 of the first sampling circuit is connected to only the first end of the total negative switch S2 and the first end of the fast charging negative switch S5, and the second sampling point a2 is connected to only the first end of the total positive switch S1, the first end of the precharge switch S3, and the first end of the fast charging positive switch S4, the first sampling circuit is not connected to both ends of any of the pre-total negative switch S2, the total positive switch S1, the precharge switch S3, the fast charging negative switch S5, and the fast charging positive switch S4, and thus the first sampling circuit does not create a high impedance loop at both ends of any switch, ensuring that the first sampling circuit is connected only on the battery side and not connected on the motor side and the charging side after the switches are disconnected. Meanwhile, the third sampling point B1 of the second sampling circuit is connected with only the second end of the total negative switch S2, the fourth sampling point B2 is connected with only the second end of the total positive switch S1 and only the second end of the pre-charging switch S3 through the pre-charging resistor R, the fifth sampling point C1 is connected with only the second end of the quick-charging negative switch S5, and the sixth sampling point C2 is connected with only the second end of the quick-charging positive switch S4, so that the second sampling circuit is not connected with both ends of any one of the pre-total negative switch S2, the total positive switch S1, the pre-charging switch S3, the quick-charging negative switch S5 and the quick-charging positive switch S4, and therefore, the second sampling circuit does not make a high-impedance loop at both ends of any one of the switches, and ensures that the second sampling circuit is connected only at the motor side and the charging pile side and is not connected at the battery side after the switches are disconnected. Therefore, the first sampling circuit and the second sampling circuit in the sampling device of the embodiment have no resistance loops at two ends of the switch, after the switch is disconnected, the first sampling circuit is isolated on the battery side, the second sampling circuit is isolated on the motor side and the charging pile side, the first sampling circuit and the second sampling circuit are mutually independent, and the high voltage of the motor side and the high voltage of the charging pile side are not communicated with the high voltage of the battery side, so that the high voltage safety of the motor side and the charging pile side after the switch is disconnected can be ensured.
The sampling device of this embodiment does not have the impedance return circuit at switch both ends, and the sampling device does not have high-pressure safety risk to the distribution, and simple structure, and is with low costs.
FIG. 2 is a schematic diagram of a diagnostic method according to an embodiment of the present invention. The embodiment also discloses a diagnostic method. The circuit and implementation of the diagnostic method sampling method of the present embodiment refer to the foregoing embodiments of the sampling apparatus.
Referring to fig. 1 and fig. 2, in the present embodiment, the diagnosis method includes:
s1, carrying out voltage acquisition on a first sampling point A1, a second sampling point A2, a third sampling point B1, a fourth sampling point B2, a fifth sampling point C1 and a sixth sampling point C2 in the sampling device, wherein the first sampling point A1 is connected with the negative electrode of the battery pack, the first end of a master negative switch S2 and the first end of a fast charge negative switch S5 and is used for sampling the grounding voltage of the negative electrode of the battery pack; the second sampling point A2 is connected with the positive electrode of the battery pack, the first end of the master positive switch S1, the first end of the pre-charging switch S3 and the first end of the quick-charging positive switch S4, and is used for sampling the grounding voltage of the positive electrode of the battery pack; the third sampling point B1 is connected with the negative pole of the motor and the second end of the master negative switch S2 and is used for sampling the earth voltage of the negative pole of the motor; the fourth sampling point B2 is connected to both the second terminal of the main positive switch S1 and the positive electrode of the motor, and is also connected to the second terminal of the pre-charge switch S3 through a pre-charge resistor R, for sampling the earth voltage of the positive electrode of the motor; the fifth sampling point C1 is connected with the second end of the quick charge negative switch S5 and the negative electrode of the charging pile and is used for sampling the voltage of the negative electrode of the charging pile to earth; the sixth sampling point C2 is connected with the second end of the quick charging positive switch S4 and the positive electrode of the charging pile and is used for sampling the voltage of the positive electrode of the charging pile to earth;
and S2, diagnosing the total negative switch S2, the pre-charging switch S3, the total positive switch S1, the quick-charging negative switch S5 and the quick-charging positive switch S4 according to the voltage acquisition result.
According to the diagnosis method, resistance loops do not exist at two ends of the switch, the sampling device does not have high-voltage safety risk on power distribution, the structure is simple, the cost is low, and the on-off state can be actively detected.
Fig. 3 is a schematic diagram of a diagnostic method during battery discharge according to an embodiment of the present invention. Referring to fig. 1 and fig. 3, in the present embodiment, specifically, the diagnosing the total positive switch S1, the total negative switch S2, the pre-charge switch S3, the fast charge positive switch S4 and the fast charge negative switch S5 according to the voltage collecting result includes:
s21, when the battery pack is discharged, closing a total negative switch S2, detecting that the absolute value of the voltage of a third sampling point B1 is not more than a first voltage threshold U1 within a first time T1, namely | UB1| ≦ U1, or detecting that the absolute value of the voltage difference between the voltage of the first sampling point A1 and the voltage of a third sampling point B1 is not less than a second voltage threshold U2 within a second time T2, namely | UA1-UB1| ≧ U2, and judging that the total negative switch S2 has a closing fault; when the absolute value of the voltage of the third sampling point B1 is detected to be greater than the first voltage threshold U1, that is, | UB1| > U1 within the first time T1, or the absolute value of the voltage difference between the voltage of the first sampling point a1 and the voltage of the third sampling point B1 is detected to be less than the second voltage threshold U2, that is, | UA1-UB1| < U2 within the second time T2, determining that the overall negative switch S2 is normally closed, wherein the first voltage threshold U1 and the second voltage threshold U2 are both greater than zero; after the total negative switch S2 is determined to be normally closed, the precharge switch S3 is closed, if it is detected that the absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the fourth sampling point B2 and the voltage at the third sampling point B1 is less than a fifth voltage threshold U5 within a third time T3, that is, | (UA2-UA1) - (UB2-UB1) | < U5, it is determined that the precharge switch S3 is normally closed, otherwise, it is determined that the precharge switch S3 has a closing fault, where the fifth voltage threshold U5 is greater than zero; or
When the battery pack is discharged, closing the pre-charging switch S3, if the absolute value of the voltage at the fourth sampling point B2 is detected to be greater than the third voltage threshold U3 within the first time T1, namely | UB2| > U3, or the absolute value of the voltage difference between the voltage at the second sampling point A2 and the voltage at the fourth sampling point B2 is detected to be less than the fourth voltage threshold U4 within the second time T2, namely | UA2-UB2| < U4, determining that the pre-charging switch S3 is normally closed, otherwise, determining that the pre-charging switch S3 has a closing fault; after the precharge switch S3 is determined to be normally closed, the total negative switch S2 is closed, if it is detected that the absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the fourth sampling point B2 and the voltage at the third sampling point B1 is less than the fifth voltage threshold U5 within the third time T3, that is, | (UA2-UA1) - (UB2-UB1) | < U5, it is determined that the total negative switch S2 is normally closed, otherwise, it is determined that the total negative switch S2 has a closing fault, where the third voltage threshold U3 and the fourth voltage threshold U4 are both greater than zero.
Whether the overall negative switch S2 is closed or not can be determined by sampling the voltage at the third sampling point B1, if the overall negative switch S3578 is closed, the third sampling point B1 can be connected to the negative electrode of the battery pack through the turned-on overall negative switch S2, that is, it is detected that the absolute value of the voltage at the third sampling point B1 is greater than the first voltage threshold U1 within the first time T1, that is, | UB1| > U1, otherwise, a closing fault occurs at the overall negative switch S2. Whether the total negative switch S2 is closed or not can also be determined by comparing the voltages of the two ends of the total negative switch S2 to the ground voltage, that is, the voltage of the first sampling point a1 and the voltage of the third sampling point B1, if the total negative switch S2 is closed, the voltage of the first sampling point a1 and the voltage of the third sampling point B1 should be almost the same, that is, the absolute value of the voltage difference between the voltage of the first sampling point a1 and the voltage of the third sampling point B1 is detected to be smaller than the second voltage threshold U2 within the second time T2, that is, | UA1-UB1| < U2, otherwise, the total negative switch S2 has a closed fault. Similarly, the closing of the precharge switch S3 may be determined by sampling the voltage at the fourth sampling point B2, or by comparing the voltages of the two ends of the precharge switch S3 to the ground, that is, the voltage at the second sampling point a2 and the voltage at the fourth sampling point B2, that is, the absolute value of the voltage at the fourth sampling point B2 detected within the first time T1 is greater than the third voltage threshold U3, that is, | UB2| > U3, or the absolute value of the voltage difference between the voltage at the second sampling point a2 and the voltage at the fourth sampling point B2 detected within the second time T2 is less than the fourth voltage threshold U4, that is, | UA2-UB2| < U4, so as to determine that the precharge switch S3 is normally closed, otherwise, the precharge switch S3 has a closing fault. In this embodiment, the closing sequence of the total negative switch S2 and the pre-charge switch S3 is not limited, and the total negative switch S2 may be closed first and then the pre-charge switch S3 may be closed first, or the pre-charge switch S3 may be closed first and then the total negative switch S2 may be closed.
S22, after determining that both the total negative switch S2 and the precharge switch S3 are normally closed, close the total positive switch S1, if it is detected within the fourth time T4 that the absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the fourth sampling point B2 and the voltage at the third sampling point B1 is smaller than the sixth voltage threshold U6, that is, | (UA2-UA1) - (UB2-UB1) | < U6, determine that the total positive switch S1 is normally closed, otherwise determine that the total positive switch S1 has a closing fault, where the sixth voltage threshold U6 is greater than zero.
The absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the fourth sampling point B2 and the voltage at the third sampling point B1 can be used to determine the magnitude relationship between the battery pack voltage UA and the motor voltage UB, and if the absolute value of the difference between the voltage differences is too large, it can be determined that the corresponding switch has a closed fault, so that the battery pack voltage UA cannot be applied to the two ends of the motor through the switch.
Fig. 4 is a schematic diagram of a diagnostic method when the battery pack stops discharging according to an embodiment of the present invention. Referring to fig. 1 and fig. 4, in the present embodiment, specifically, the diagnosing the total positive switch S1, the total negative switch S2, the pre-charge switch S3, the fast charge positive switch S4 and the fast charge negative switch S5 according to the voltage collecting result includes:
s23, when the battery pack stops discharging, the total positive switch S1 is turned off, and when the absolute value of the difference value between the voltage difference of the voltage of the second sampling point A2 and the voltage of the first sampling point A1 and the voltage difference of the voltage of the fourth sampling point B2 and the voltage of the third sampling point B1 is not larger than a seventh voltage threshold value U7 within a fifth time T5, namely | (UA2-UA1) - (UB2-UB1) | is not larger than U7, the total positive switch S1 is judged to have an open fault; when detecting that the absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the fourth sampling point B2 and the voltage at the third sampling point B1 is greater than a seventh voltage threshold value U7 within a fifth time T5, that is, | (UA2-UA1) - (UB2-UB1) | > U7, determining that the total positive switch S1 is normally open, wherein the seventh voltage threshold value U7 is greater than zero; after the total positive switch S1 is normally turned off, turning off the total negative switch S2, if it is detected that the absolute value of the voltage at the third sampling point B1 is smaller than the eighth voltage threshold U8 within the sixth time T6, or it is detected that the absolute value of the voltage difference between the voltage at the first sampling point a1 and the voltage at the third sampling point B1 is greater than the ninth voltage threshold U9 within the seventh time T7, that is, | UA1-UB1| > U9, turning off the total negative switch S2 normally, otherwise, turning off the total negative switch S2, where the eighth voltage threshold U8 and the ninth voltage threshold U9 are both greater than zero; or
When the battery pack stops discharging, the total negative switch S2 is turned off, if the absolute value of the difference value between the voltage difference between the voltage at the second sampling point A2 and the voltage at the first sampling point A1 and the voltage difference between the voltage at the fourth sampling point B2 and the voltage at the third sampling point B1 is detected to be greater than the seventh voltage threshold U7 within the fifth time T5, namely | (UA2-UA1) - (UB2-UB1) | > U7, the total negative switch S2 is judged to be normally turned off, otherwise, the total negative switch S2 is judged to have an open fault; after the total negative switch S2 is judged to be normally opened, the total positive switch S1 is opened, if it is detected that the absolute value of the voltage at the fourth sampling point B2 is smaller than the tenth voltage threshold U10 within the sixth time T6, that is, | UB2| < U10, or it is detected that the absolute value of the voltage difference between the voltage at the second sampling point a2 and the voltage at the fourth sampling point B2 is greater than the eleventh voltage threshold U11 within the seventh time T7, that is, | UA2-UB2| > U11, it is judged that the total positive switch S1 is normally opened, otherwise, it is judged that the total positive switch S1 has an opening fault, wherein the tenth voltage threshold U10 and the eleventh voltage threshold U11 are both greater than zero.
The absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the fourth sampling point B2 and the voltage at the third sampling point B1 can be used to determine the magnitude relationship between the battery pack voltage UA and the motor voltage UB, and if the absolute value of the difference between the voltage differences is too small, it can be determined that the corresponding switch has an open failure, so that the battery pack voltage UA can still be applied to the two ends of the motor through the switch. In this embodiment, the closing sequence of closing the total positive switch S1 and the total negative switch S2 is not limited, and the total negative switch S2 may be closed first and then the total positive switch S1 may be closed, or the total positive switch S1 may be closed first and then the total negative switch S2 may be closed.
Whether the overall negative switch S2 is turned off or not can be determined by sampling the voltage at the third sampling point B1, if the overall negative switch S2 is turned off, the third sampling point B1 can be grounded through the insulation resistor RNB, that is, the absolute value of the voltage at the third sampling point B1 is detected to be smaller than the eighth voltage threshold U8 within the sixth time T6, that is, | UB1| < U8, otherwise, the overall negative switch S2 has an open fault. Whether the total negative switch S2 is turned off or not can also be determined by comparing the voltages of the two ends of the total negative switch S2 to the ground, that is, the voltage at the first sampling point a1 and the voltage at the third sampling point B1, if the total negative switch S2 is turned off, the difference between the voltage at the first sampling point a1 and the voltage at the third sampling point B1 is large, that is, the absolute value of the voltage difference between the voltage at the first sampling point a1 and the voltage at the third sampling point B1 is detected to be greater than the ninth voltage threshold U9 within the seventh time T7, | UA1-UB1| > U9, otherwise, the total negative switch S2 has an open fault. Similarly, the total positive switch S1 may be turned off by sampling the voltage at the fourth sampling point B2, or by comparing the voltages of the two ends of the total positive switch S1 to ground, that is, the voltage at the second sampling point a2 and the voltage at the fourth sampling point B2, that is, the absolute value of the voltage at the fourth sampling point B2 detected in the sixth time T6 is smaller than the tenth voltage threshold U10, | UB2| < U10, or the absolute value of the voltage difference between the voltage at the second sampling point a2 and the voltage at the fourth sampling point B2 detected in the seventh time T7 is larger than the eleventh voltage threshold U11, that is, | UA2-UB2| > U11, so as to determine that the total positive switch S1 is turned off normally, otherwise, the total positive switch S1 has an open fault.
Fig. 5 is a schematic diagram of a diagnosis method during battery pack charging according to an embodiment of the present invention. Referring to fig. 1 and fig. 5, in the present embodiment, specifically, the diagnosing the total positive switch S1, the total negative switch S2, the pre-charge switch S3, the fast charge positive switch S4 and the fast charge negative switch S5 according to the voltage collecting result includes:
s24, when the battery pack is charged, closing the quick charging negative switch S5, detecting that the absolute value of the voltage of the fifth sampling point C1 is not more than the twelfth voltage threshold U12 within the eighth time T8, namely | UC1| ≦ U12, or detecting that the absolute value of the voltage difference between the voltage of the first sampling point A1 and the voltage of the fifth sampling point C1 is not less than the thirteenth voltage threshold U13 within the ninth time T9, namely | UA1-UC1| ≧ U13, and judging that the quick charging negative switch S5 has a closing fault; when the absolute value of the voltage at the fifth sampling point C1 is detected to be greater than the twelfth voltage threshold U12, that is, | UC1| > U12, within the eighth time T8, or the absolute value of the voltage difference between the voltage at the first sampling point a1 and the voltage at the fifth sampling point C1 is detected to be less than the thirteenth voltage threshold U13, that is, | UA1-UC1| < U13, the quick-charge negative switch S5 is determined to be normally closed, wherein, both the twelfth voltage threshold U12 and the thirteenth voltage threshold U13 are greater than zero; after the fast charging negative switch S5 is determined to be normally closed, the fast charging positive switch S4 is closed, if it is detected within the tenth time T10 that the absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the sixth sampling point C2 and the voltage at the fifth sampling point C1 is less than a sixteenth voltage threshold U16, | (UA2-UA1) - (UC2-UC1) | < U16, it is determined that the fast charging positive switch S4 is normally closed, otherwise, it is determined that the fast charging positive switch S4 has a closed fault, where the sixteenth voltage threshold U16 is greater than zero; or
When the battery pack is charged, closing the fast charging positive switch S4, if it is detected that the absolute value of the voltage at the sixth sampling point C2 is greater than the fourteenth voltage threshold U14 within the eighth time T8, that is, | UC2| > U14, or it is detected that the absolute value of the voltage difference between the voltage at the second sampling point a2 and the voltage at the sixth sampling point C2 is less than the fifteenth voltage threshold U15 within the ninth time T9, that is, | UA2-UC2| < U15, determining that the fast charging positive switch S4 is normally closed, otherwise determining that the fast charging positive switch S4 has a closing fault; after the fast charging positive switch S4 is judged to be normally closed, the fast charging negative switch S5 is closed, if it is detected within the tenth time T10 that the absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the sixth sampling point C2 and the voltage at the fifth sampling point C1 is less than the sixteenth voltage threshold U16, that is, | (UA2-UA1) - (UC2-UC1) | < U16, it is judged that the fast charging negative switch S5 is normally closed, otherwise, it is judged that the fast charging negative switch S5 has a closing fault, where the fourteenth voltage threshold U14 and the fifteenth voltage threshold U15 are both greater than zero.
Whether the quick-charging negative switch S5 is closed or not can be determined by sampling the voltage at the fifth sampling point C1, if the quick-charging negative switch S3578 is closed, the fifth sampling point C1 can be connected to the negative electrode of the battery pack through the turned-on quick-charging negative switch S5, that is, it is detected that the absolute value of the voltage at the fifth sampling point C1 is greater than the twelfth voltage threshold U12 within the eighth time T8, that is, | UC1| > U12, otherwise, a closing failure occurs in the quick-charging negative switch S5. Whether the fast charging negative switch S5 is closed or not can also be determined by comparing the voltages of the two ends of the fast charging negative switch S5 to the ground, that is, the voltage of the first sampling point a1 and the voltage of the fifth sampling point C1, if the two ends of the fast charging negative switch S5 are closed, the voltage of the first sampling point a1 and the voltage of the fifth sampling point C1 should be almost the same, that is, the absolute value of the voltage difference between the voltage of the first sampling point a1 and the voltage of the fifth sampling point C1 is detected to be smaller than the thirteenth voltage threshold value U13 within the ninth time T9, that is, | UA1-UC1| < U13, otherwise, the fast charging negative switch S5 has a closed fault. Similarly, the closing of the fast charge positive switch S4 may be determined by sampling the voltage at the sixth sampling point C2, or by comparing the voltages of the two ends of the fast charge positive switch S4 to the ground, that is, the voltage at the second sampling point a2 and the voltage at the sixth sampling point C2, that is, the absolute value of the voltage at the sixth sampling point C2 detected within the eighth time T8 is greater than the fourteenth voltage threshold U14, that is, | UC2| > U14, or the absolute value of the voltage difference between the voltage at the second sampling point a2 and the voltage at the sixth sampling point C2 detected within the ninth time T9 is less than the fifteenth voltage threshold U15, that is, | UA2-UC2| < U15, so as to determine that the fast charge positive switch S4 is normally closed, otherwise, the close fault occurs in the fast charge positive switch S4. In this embodiment, the closing sequence of the fast charging positive switch S4 and the fast charging negative switch S5 is not limited, and the fast charging negative switch S5 may be closed first and then the fast charging positive switch S4 may be closed, or the fast charging positive switch S4 may be closed first and then the fast charging negative switch S5 may be closed.
The absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the sixth sampling point C2 and the voltage at the fifth sampling point C1 can be used to determine the magnitude relationship between the battery pack voltage UA at the battery side and the battery voltage at the motor side, and if the absolute value of the difference between the voltage differences is too large, it can be determined that a corresponding switch has a closed fault, so that the battery pack voltage UA at the battery side cannot be applied to the second end of the fast charge negative switch S5 and the second end of the fast charge positive switch S4 at the motor side through the switch.
Fig. 6 is a schematic diagram of a diagnostic method when the battery pack stops charging according to an embodiment of the present invention. Referring to fig. 1 and fig. 6, in the present embodiment, specifically, the diagnosing the total positive switch S1, the total negative switch S2, the pre-charge switch S3, the fast charge positive switch S4 and the fast charge negative switch S5 according to the voltage collecting result includes:
s25, when the battery pack stops charging, the quick charging positive switch S4 is turned off, and when the absolute value of the difference value between the voltage difference of the voltage of the second sampling point A2 and the voltage of the first sampling point A1 and the voltage difference of the voltage of the sixth sampling point C2 and the voltage of the fifth sampling point C1 is not greater than a seventeenth voltage threshold value U17 within eleventh time T11, namely | (UA2-UA1) - (UC2-UC1) | is not greater than U17, the quick charging positive switch S4 is judged to have an open fault; when detecting that the absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the sixth sampling point C2 and the voltage at the fifth sampling point C1 is greater than a seventeenth voltage threshold value U17 within an eleventh time T11, | (UA2-UA1) - (UC2-UC1) | > U17, determining that the fast charge positive switch S4 is normally open, wherein the seventeenth voltage threshold value U17 is greater than zero; after the fast charging positive switch S4 is judged to be normally turned off, the fast charging negative switch S5 is turned off, if it is detected that the absolute value of the voltage at the fifth sampling point C1 is smaller than the eighteenth voltage threshold U18 within the twelfth time T12, that is, | UC1| < U18, or it is detected that the absolute value of the voltage difference between the voltage at the first sampling point a1 and the voltage at the fifth sampling point C1 is greater than the nineteenth voltage threshold U19 within the thirteenth time T13, that is, | UA1-UC1| > U19, it is judged that the fast charging negative switch S5 is normally turned off, otherwise, it is judged that the fast charging negative switch S5 has an off fault, wherein both the eighteenth voltage threshold U18 and the nineteenth voltage threshold U19 are greater than zero; or
When the battery pack stops charging, the quick-charging negative switch S5 is turned off, if the absolute value of the difference value between the voltage difference between the voltage at the second sampling point A2 and the voltage at the first sampling point A1 and the voltage difference between the voltage at the sixth sampling point C2 and the voltage at the fifth sampling point C1 is detected to be greater than the seventeenth voltage threshold value U17 within the eleventh time T11, namely | (UA2-UA1) - (UC2-UC1) | > U17, the quick-charging negative switch S5 is judged to be normally turned off, otherwise, the quick-charging negative switch S5 is judged to have an open fault; after the fast charging negative switch S5 is judged to be normally disconnected, the fast charging positive switch S4 is disconnected, if the absolute value of the voltage of the sixth sampling point C2 is detected to be smaller than the twentieth voltage threshold U20 within the twelfth time T12, namely | UC2| < U20, or the absolute value of the voltage difference between the voltage of the second sampling point A2 and the voltage of the sixth sampling point C2 is detected to be larger than the twenty-first voltage threshold U21 within the thirteenth time T13, namely | UA2-UC2| > U21, the fast charging positive switch S4 is judged to be normally disconnected, otherwise, the fast charging positive switch S4 is judged to have disconnection fault; the twentieth voltage threshold U20 and the twenty-first voltage threshold U21 are both greater than zero.
The absolute value of the difference between the voltage at the second sampling point a2 and the voltage at the first sampling point a1 and the voltage difference between the voltage at the sixth sampling point C2 and the voltage at the fifth sampling point C1 can be used to determine the magnitude relationship between the battery pack voltage UA and the motor voltage UB, and if the absolute value of the difference is too small, it can be determined that the corresponding switch has an open failure, and the battery pack voltage UA on the battery side can still be applied to the second end of the fast-charging negative switch S5 and the second end of the fast-charging positive switch S4 on the motor side through the switches.
Whether the fast charging negative switch S5 is turned off or not can be determined by sampling the voltage at the fifth sampling point C1, if the fast charging negative switch S5 is turned off, the fifth sampling point C1 can be grounded through the insulation resistor RNC, that is, it is detected within the twelfth time T12 that the absolute value of the voltage at the fifth sampling point C1 is smaller than the eighteenth voltage threshold U18, that is, | UC1| < U18, otherwise, the fast charging negative switch S5 fails to turn off. Whether the fast charging negative switch S5 is turned off or not can also be determined by comparing the voltages of the two ends of the fast charging negative switch S5 to the ground, that is, the voltage at the first sampling point a1 and the voltage at the fifth sampling point C1, if the fast charging negative switch S5 is turned off, the voltage difference between the voltage at the first sampling point a1 and the voltage at the fifth sampling point C1 is relatively large, that is, the absolute value of the voltage difference between the voltage at the first sampling point a1 and the voltage at the fifth sampling point C1 is detected to be greater than the nineteenth voltage threshold U19 within the thirteenth time T13, that is, | UA1-UC1| > U19, otherwise, the fast charging negative switch S5 has an open fault. Similarly, the open fast charge positive switch S4 may be determined by sampling the voltage at the sixth sampling point C2, or by comparing the voltages of the two ends of the fast charge positive switch S4 to the ground, that is, the voltage at the second sampling point a2 and the voltage at the sixth sampling point C2, that is, the absolute value of the voltage at the sixth sampling point C2 detected within the twelfth time T12 is greater than the twentieth voltage threshold U20, that is, | UC2| < U20, or the absolute value of the voltage difference between the voltage at the second sampling point a2 and the voltage at the sixth sampling point C2 detected within the thirteenth time T13 is greater than the twenty-first voltage threshold U21, that is, | UA2-UC2| > U21, so as to determine that the fast charge positive switch S4 is normally open, otherwise, the open fault occurs in the fast charge positive switch S4.
In one embodiment, the diagnosing the total positive switch S1, the total negative switch S2, the pre-charge switch S3, the fast charge positive switch S4 and the fast charge negative switch S5 according to the voltage collecting result includes:
in a fourteenth time T14, disconnecting the total negative switch S2, the total positive switch S1, the precharge switch S3, the quick charge negative switch S5 and the quick charge positive switch S4, if the absolute value of the voltage of a third sampling point B1 is detected to be smaller than a twenty-second voltage threshold value U22, namely | UB1| < U22, judging that the total negative switch S2 is normally disconnected, otherwise, judging that the total negative switch S2 has disconnection fault; when the absolute value of the voltage of the fourth sampling point B2 is detected to be smaller than a twenty-third voltage threshold value U23, namely | UB2| < U23, the total positive switch S1 and the pre-charging switch S3 are judged to be normally disconnected, and otherwise, the total positive switch S1 or the pre-charging switch S3 is judged to have disconnection fault; when the absolute value of the voltage of the fifth sampling point C1 is detected to be smaller than a twenty-fourth voltage threshold value U24, namely | UC1| < U24, judging that the quick-charging negative switch S5 is normally disconnected, otherwise, judging that the quick-charging negative switch S5 is disconnected; when the absolute value of the voltage of the sixth sampling point C2 is detected to be smaller than a twenty-fifth voltage threshold value U25, namely | UC2| < U25, judging that the fast charging positive switch S4 is normally disconnected, otherwise, judging that the fast charging positive switch S4 is disconnected; the twenty-second voltage threshold U22, the twenty-third voltage threshold U23, the twenty-fourth voltage threshold U24, and the twenty-fifth voltage threshold U25 are all greater than zero.
This embodiment can be used for in the initial detection of the high-voltage distribution of group battery, and when bonding according to high-voltage distribution circuit, the positive pole of group battery is positive value voltage, and the negative pole of group battery is negative value voltage, if corresponding switch breaks down, then corresponding sampling point will be connected to the positive pole or the negative pole of group battery through the switch that switches on, then the voltage of corresponding sampling point is nonzero. Therefore, according to the fact that the absolute value of the voltage of the corresponding sampling point is smaller than the corresponding voltage threshold value, the corresponding switch can be judged to be normally disconnected, and otherwise, the corresponding switch is disconnected and fails.
According to the diagnosis method provided by the embodiment of the invention, resistance loops do not exist at two ends of the switch, the sampling device has no high-voltage safety risk to power distribution, the structure is simple, the cost is low, and the on-off state can be actively detected.
The embodiment of the invention also provides a vehicle which comprises the sampling device of any one of the embodiments. The implementation of the vehicle can be referred to the above embodiment of the sampling circuit, and repeated descriptions are omitted.
The vehicle provided by the embodiment of the invention has no resistance loops at two ends of the switch, and the sampling device has no high-voltage safety risk to power distribution and has simple structure and low cost.
Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A sampling device, comprising a first sampling circuit and a second sampling circuit;
the first sampling circuit includes a first sampling point (A1), a second sampling point (A2), and a first ground point (G1); the first sampling point (A1) is connected with the negative electrode of the battery pack, the first end of the master negative switch (S2) and the first end of the quick charge negative switch (S5) and is used for sampling the grounding voltage of the negative electrode of the battery pack; the second sampling point (A2) is connected with the positive electrode of the battery pack, the first end of the main positive switch (S1), the first end of the pre-charging switch (S3) and the first end of the quick-charging positive switch (S4) and is used for sampling the grounding voltage of the positive electrode of the battery pack; the first grounding point (G1) is grounded;
the second sampling circuit includes a third sampling point (B1), a fourth sampling point (B2), a fifth sampling point (C1), a sixth sampling point (C2), and a second ground point (G2); the third sampling point (B1) is connected with the negative pole of the motor and the second end of the master negative switch (S2) and is used for sampling the grounding voltage of the negative pole of the motor; the fourth sampling point (B2) is connected to both the second terminal of the main positive switch (S1) and the positive electrode of the motor, and is also connected to the second terminal of the pre-charge switch (S3) through a pre-charge resistor (R) for sampling the earth voltage of the positive electrode of the motor; the fifth sampling point (C1) is connected with the second end of the quick charge negative switch (S5) and the negative electrode of the charging pile and is used for sampling the grounding voltage of the negative electrode of the charging pile; the sixth sampling point (C2) is connected with the second end of the quick charging positive switch (S4) and the positive electrode of the charging pile and is used for sampling the grounding voltage of the positive electrode of the charging pile; the second grounding point (G2) is grounded.
2. The sampling device of claim 1, wherein the total negative switch (S2), the total positive switch (S1), the pre-charge switch (S3), the fast-charge negative switch (S5), and the fast-charge positive switch (S4) are all relay switches.
3. The sampling device of claim 1, wherein said second sampling circuit further comprises an ADC sampling circuit;
the ADC sampling circuit comprises a first receiving end, a second receiving end, a third receiving end, a fourth receiving end and a grounding end, wherein the first receiving end of the ADC sampling circuit is connected with the third sampling point (B1), the second receiving end of the ADC sampling circuit is connected with the fourth sampling point (B2), the third receiving end of the ADC sampling circuit is connected with the fifth sampling point (C1), the fourth receiving end of the ADC sampling circuit is connected with the sixth sampling point (C2), and the grounding end of the ADC sampling circuit is connected with the second grounding point (G2).
4. A diagnostic method, comprising:
voltage collection is carried out on a first sampling point (A1), a second sampling point (A2), a third sampling point (B1), a fourth sampling point (B2), a fifth sampling point (C1) and a sixth sampling point (C2) in a sampling device, wherein the first sampling point (A1) is connected with the negative electrode of a battery pack, the first end of a master negative switch (S2) and the first end of a quick charge negative switch (S5) and is used for sampling the grounding voltage of the negative electrode of the battery pack; the second sampling point (A2) is connected with the positive electrode of the battery pack, the first end of the main positive switch (S1), the first end of the pre-charging switch (S3) and the first end of the quick-charging positive switch (S4) and is used for sampling the grounding voltage of the positive electrode of the battery pack; the third sampling point (B1) is connected with the negative pole of the motor and the second end of the master negative switch (S2) and is used for sampling the grounding voltage of the negative pole of the motor; the fourth sampling point (B2) is connected to both the second terminal of the main positive switch (S1) and the positive electrode of the motor, and is also connected to the second terminal of the pre-charge switch (S3) through a pre-charge resistor, for sampling the earth voltage of the positive electrode of the motor; the fifth sampling point (C1) is connected with the second end of the quick charge negative switch (S5) and the negative electrode of the charging pile and is used for sampling the grounding voltage of the negative electrode of the charging pile; the sixth sampling point (C2) is connected with the second end of the quick charging positive switch (S4) and the positive electrode of the charging pile and is used for sampling the grounding voltage of the positive electrode of the charging pile;
diagnosing the master positive switch (S1), the master negative switch (S2), the pre-charge switch (S3), the fast charge positive switch (S4), and the fast charge negative switch (S5) according to a voltage acquisition result.
5. The diagnostic method of claim 4, wherein diagnosing the total positive switch (S1), the total negative switch (S2), the pre-charge switch (S3), the fast charge positive switch (S4), and the fast charge negative switch (S5) according to the voltage acquisition result comprises:
when the battery pack is discharged, closing the overall negative switch (S2), and judging that the overall negative switch (S2) has a closing fault when detecting that the absolute value of the voltage of the third sampling point (B1) is not more than a first voltage threshold (U1) in a first time (T1) or the absolute value of the voltage difference of the voltage of the first sampling point (A1) and the voltage of the third sampling point (B1) is not less than a second voltage threshold (U2) in a second time (T2); determining that the overall negative switch (S2) is normally closed when the absolute value of the voltage of the third sampling point (B1) is detected to be greater than the first voltage threshold (U1) within the first time (T1) or the absolute value of the voltage difference between the voltage of the first sampling point (A1) and the voltage of the third sampling point (B1) is detected to be less than the second voltage threshold (U2) within the second time (T2), wherein the first voltage threshold (U1) and the second voltage threshold (U2) are both greater than zero; after the total negative switch (S2) is judged to be normally closed, the pre-charging switch (S3) is closed, if the absolute value of the difference between the voltage difference of the voltage of the second sampling point (A2) and the voltage of the first sampling point (A1) and the voltage difference of the voltage of the fourth sampling point (B2) and the voltage of the third sampling point (B1) is detected to be less than a fifth voltage threshold value (U5) within a third time (T3), the pre-charging switch (S3) is judged to be normally closed, otherwise, the pre-charging switch (S3) is judged to have a closing fault, wherein the fifth voltage threshold value (U5) is greater than zero; or
When the battery pack is discharged, closing the pre-charging switch (S3), if the absolute value of the voltage of the fourth sampling point (B2) is detected to be greater than a third voltage threshold (U3) in the first time (T1), or the absolute value of the voltage difference between the voltage of the second sampling point (A2) and the voltage of the fourth sampling point (B2) is detected to be less than a fourth voltage threshold (U4) in the second time (T2), determining that the pre-charging switch (S3) is normally closed, otherwise, determining that the pre-charging switch (S3) has a closing fault; after the precharge switch (S3) is determined to be normally closed, closing the overall negative switch (S2), if the absolute value of the difference between the voltage of the second sampling point (a2) and the voltage of the first sampling point (a1) and the voltage difference between the voltage of the fourth sampling point (B2) and the voltage of the third sampling point (B1) is detected to be less than the fifth voltage threshold (U5) within the third time (T3), determining that the overall negative switch (S2) is normally closed, otherwise determining that a closing fault occurs to the overall negative switch (S2), wherein the third voltage threshold (U3) and the fourth voltage threshold (U4) are both greater than zero;
after determining that both the total negative switch (S2) and the pre-charge switch (S3) are normally closed, closing the total positive switch (S1), if the absolute value of the difference between the voltage of the second sampling point (A2) and the voltage of the first sampling point (A1) and the voltage difference between the voltage of the fourth sampling point (B2) and the voltage of the third sampling point (B1) is detected to be less than a sixth voltage threshold value (U6) within a fourth time (T4), determining that the total positive switch (S1) is normally closed, otherwise determining that a closing fault occurs in the total positive switch (S1), wherein the sixth voltage threshold value (U6) is greater than zero.
6. The diagnostic method of claim 4, wherein diagnosing the total positive switch (S1), the total negative switch (S2), the pre-charge switch (S3), the fast charge positive switch (S4), and the fast charge negative switch (S5) according to the voltage acquisition result comprises:
when the battery pack stops discharging, the total positive switch (S1) is turned off, and when the absolute value of the difference value of the voltage difference between the voltage of the second sampling point (A2) and the voltage of the first sampling point (A1) and the voltage difference between the voltage of the fourth sampling point (B2) and the voltage of the third sampling point (B1) is not larger than a seventh voltage threshold value (U7) in a fifth time (T5), the total positive switch (S1) is determined to be in an open fault; determining that the total positive switch (S1) is normally open when detecting that the absolute value of the difference between the voltage difference of the voltage at the second sampling point (A2) and the voltage at the first sampling point (A1) and the voltage difference of the voltage at the fourth sampling point (B2) and the voltage at the third sampling point (B1) is greater than a seventh voltage threshold (U7) within the fifth time (T5), wherein the seventh voltage threshold (U7) is greater than zero; after the total positive switch (S1) is judged to be normally opened, the total negative switch (S2) is opened, if the absolute value of the voltage of the third sampling point (B1) is detected to be smaller than an eighth voltage threshold (U8) in a sixth time (T6), or the absolute value of the voltage difference between the voltage of the first sampling point (A1) and the voltage of the third sampling point (B1) is detected to be larger than a ninth voltage threshold (U9) in a seventh time (T7), the total negative switch (S2) is judged to be normally opened, otherwise, the total negative switch (S2) is judged to be opened, wherein the eighth voltage threshold (U8) and the ninth voltage threshold (U9) are both larger than zero; or
When the battery pack stops discharging, opening the master negative switch (S2), if the absolute value of the difference between the voltage difference of the voltage of the second sampling point (A2) and the voltage of the first sampling point (A1) and the voltage difference of the voltage of the fourth sampling point (B2) and the voltage of the third sampling point (B1) is detected to be larger than the seventh voltage threshold value (U7) in the fifth time (T5), judging that the master negative switch (S2) is normally opened, otherwise, judging that the master negative switch (S2) has an opening fault; after the total negative switch (S2) is judged to be normally opened, the total positive switch (S1) is opened, if the absolute value of the voltage of the fourth sampling point (B2) is detected to be smaller than a tenth voltage threshold (U10) in the sixth time (T6), or the absolute value of the voltage difference between the voltage of the second sampling point (A2) and the voltage of the fourth sampling point (B2) is detected to be larger than an eleventh voltage threshold (U11) in the seventh time (T7), the total positive switch (S1) is judged to be normally opened, otherwise, the total positive switch (S1) is judged to have an opening fault, wherein the tenth voltage threshold (U10) and the eleventh voltage threshold (U11) are both larger than zero.
7. The diagnostic method of claim 4, wherein diagnosing the total positive switch (S1), the total negative switch (S2), the pre-charge switch (S3), the fast charge positive switch (S4), and the fast charge negative switch (S5) according to the voltage acquisition result comprises:
when the battery pack is charged, closing the quick charge negative switch (S5), and detecting that the absolute value of the voltage of the fifth sampling point (C1) is not more than a twelfth voltage threshold (U12) in an eighth time (T8), or detecting that the absolute value of the voltage difference between the voltage of the first sampling point (A1) and the voltage of the fifth sampling point (C1) is not less than a thirteenth voltage threshold (U13) in a ninth time (T9), determining that the quick charge negative switch (S5) has a closing fault; determining that the quick charge negative switch (S5) is normally closed when the absolute value of the voltage at the fifth sampling point (C1) is detected to be greater than the twelfth voltage threshold (U12) within the eighth time (T8) or the absolute value of the voltage difference between the voltage at the first sampling point (A1) and the voltage at the fifth sampling point (C1) is detected to be less than the thirteenth voltage threshold (U13) within the ninth time (T9), wherein the twelfth voltage threshold (U12) and the thirteenth voltage threshold (U13) are both greater than zero; after the quick charge negative switch (S5) is judged to be normally closed, the quick charge positive switch (S4) is closed, if the absolute value of the difference between the voltage difference of the voltage of the second sampling point (A2) and the voltage of the first sampling point (A1) and the difference between the voltage of the sixth sampling point (C2) and the voltage of the fifth sampling point (C1) is detected to be less than a sixteenth voltage threshold value (U16) within a tenth time (T10), the quick charge positive switch (S4) is judged to be normally closed, otherwise, the quick charge positive switch (S4) is judged to have a closing fault, wherein the sixteenth voltage threshold value (U16) is greater than zero; or
When the battery pack is charged, closing the quick charge positive switch (S4), if the absolute value of the voltage of the sixth sampling point (C2) is detected to be greater than a fourteenth voltage threshold (U14) in the eighth time (T8), or the absolute value of the voltage difference between the voltage of the second sampling point (A2) and the voltage of the sixth sampling point (C2) is detected to be less than a fifteenth voltage threshold (U15) in the ninth time (T9), determining that the quick charge positive switch (S4) is normally closed, otherwise, determining that the quick charge positive switch (S4) has a closing fault; after the fast charging positive switch (S4) is determined to be normally closed, closing the fast charging negative switch (S5), if it is detected that the absolute value of the difference between the voltage at the second sampling point (a2) and the voltage at the first sampling point (a1) and the difference between the voltage at the sixth sampling point (C2) and the voltage at the fifth sampling point (C1) is less than the sixteenth voltage threshold (U16) within the tenth time (T10), determining that the fast charging negative switch (S5) is normally closed, otherwise determining that the fast charging negative switch (S5) has a closing fault, wherein the fourteenth voltage threshold (U14) and the fifteenth voltage threshold (U15) are both greater than zero.
8. The diagnostic method of claim 4, wherein diagnosing the total positive switch (S1), the total negative switch (S2), the pre-charge switch (S3), the fast charge positive switch (S4), and the fast charge negative switch (S5) according to the voltage acquisition result comprises:
when the battery pack stops charging, the quick charge positive switch (S4) is turned off, and when the fact that the absolute value of the difference value of the voltage difference between the voltage of the second sampling point (A2) and the voltage of the first sampling point (A1) and the voltage difference between the voltage of the sixth sampling point (C2) and the voltage of the fifth sampling point (C1) is not larger than a seventeenth voltage threshold value (U17) is detected in eleventh time (T11), the quick charge positive switch (S4) is judged to have an open fault; determining that the fast charging positive switch (S4) is normally open when detecting that the absolute value of the difference between the voltage at the second sampling point (A2) and the voltage at the first sampling point (A1) and the voltage difference between the voltage at the sixth sampling point (C2) and the voltage at the fifth sampling point (C1) is greater than a seventeenth voltage threshold value (U17) within the eleventh time (T11), wherein the seventeenth voltage threshold value (U17) is greater than zero; after the quick charge positive switch (S4) is judged to be normally opened, the quick charge negative switch (S5) is opened, if the absolute value of the voltage of the fifth sampling point (C1) is detected to be smaller than an eighteenth voltage threshold (U18) in a twelfth time (T12), or the absolute value of the voltage difference between the voltage of the first sampling point (A1) and the voltage of the fifth sampling point (C1) is detected to be larger than a nineteenth voltage threshold (U19) in a thirteenth time (T13), the quick charge negative switch (S5) is judged to be normally opened, otherwise, the quick charge negative switch (S5) is judged to have an opening fault, wherein the eighteenth voltage threshold (U18) and the nineteenth voltage threshold (U19) are both larger than zero; or
When the battery pack stops charging, the quick-charging negative switch (S5) is turned off, if the absolute value of the difference between the voltage difference of the voltage at the second sampling point (A2) and the voltage at the first sampling point (A1) and the difference between the voltage at the sixth sampling point (C2) and the voltage at the fifth sampling point (C1) is detected to be greater than the seventeenth voltage threshold value (U17) within the eleventh time (T11), the quick-charging negative switch (S5) is judged to be normally turned off, otherwise, the quick-charging negative switch (S5) is judged to have an open fault; after the quick charge negative switch (S5) is judged to be normally opened, the quick charge positive switch (S4) is opened, if the absolute value of the voltage of the sixth sampling point (C2) is detected to be smaller than a twentieth voltage threshold (U20) in the twelfth time (T12), or the absolute value of the voltage difference between the voltage of the second sampling point (A2) and the voltage of the sixth sampling point (C2) is detected to be larger than a twenty-first voltage threshold (U21) in the thirteenth time (T13), the quick charge positive switch (S4) is judged to be normally opened, otherwise, the quick charge positive switch (S4) is judged to have an opening fault; the twentieth voltage threshold (U20), the twenty-first voltage threshold (U21) are each greater than zero.
9. The diagnostic method of claim 4, wherein diagnosing the total positive switch (S1), the total negative switch (S2), the pre-charge switch (S3), the fast charge positive switch (S4), and the fast charge negative switch (S5) according to the voltage acquisition result comprises:
during a fourteenth time (T14), opening the total negative switch (S2), the total positive switch (S1), the pre-charging switch (S3), the quick-charging negative switch (S5) and the quick-charging positive switch (S4), if the absolute value of the voltage of the third sampling point (B1) is detected to be less than a twenty-second voltage threshold value (U22), determining that the total negative switch (S2) is normally opened, otherwise determining that the total negative switch (S2) has an opening fault; detecting that the absolute value of the voltage of the fourth sampling point (B2) is less than a twenty-third voltage threshold (U23), determining that the main positive switch (S1) or the pre-charging switch (S3) is normally turned off, otherwise determining that the main positive switch (S1) or the pre-charging switch (S3) has an open fault; when the absolute value of the voltage of the fifth sampling point (C1) is detected to be smaller than a twenty-fourth voltage threshold (U24), the quick-charge negative switch (S5) is judged to be normally disconnected, otherwise, the quick-charge negative switch (S5) is judged to have a disconnection fault; when the absolute value of the voltage of the sixth sampling point (C2) is detected to be smaller than a twenty-fifth voltage threshold value (U25), the quick-charging positive switch (S4) is judged to be normally disconnected, otherwise, the quick-charging positive switch (S4) is judged to have a disconnection fault; the twenty-second voltage threshold (U22), the twenty-third voltage threshold (U23), the twenty-fourth voltage threshold (U24), the twenty-fifth voltage threshold (U25) are all greater than zero.
10. A vehicle comprising a sampling device according to any one of claims 1-3.
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