CN114280470A - State detection method, isolation detection circuit and equipment for electric vehicle relay - Google Patents
State detection method, isolation detection circuit and equipment for electric vehicle relay Download PDFInfo
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- CN114280470A CN114280470A CN202111473333.2A CN202111473333A CN114280470A CN 114280470 A CN114280470 A CN 114280470A CN 202111473333 A CN202111473333 A CN 202111473333A CN 114280470 A CN114280470 A CN 114280470A
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Abstract
The invention discloses an isolation detection circuit of an electric vehicle relay, which comprises four sampling circuits, wherein the sampling circuits are respectively arranged at two ends of a positive electrode and a negative electrode of a power battery and two ends of a positive electrode and a negative electrode of a charging port to obtain four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-, two of the four sampling voltages are combined, the four sampling voltages respectively pass through a first solid-state relay and a second solid-state relay, the obtained signals are processed by a processor, and the working states of the positive electrode relay and the negative electrode relay are judged by adopting voltage differences of different voltages. The voltage of four ports, namely the voltage + of the power battery, the voltage + of the charging port and the voltage-of the charging port, is sampled respectively, the four sampling voltages are combined in pairs, the result obtained by combination is judged, the state of the quick-charging relay is determined, the detection accuracy is greatly improved, the low-side relay can be detected, the safety is high, and the cost is low.
Description
Technical Field
The invention belongs to the technical field of electric vehicle control circuits, and particularly relates to a state detection method, an isolation detection circuit and equipment for an electric vehicle relay.
Background
At present, the domestic electric automobile industry develops rapidly, and in a charging circuit of an electric automobile, the connection and disconnection between a battery end and a charging port are controlled through a quick charging relay. When charging, the control is filled the relay closure soon for the mouth that charges communicates with battery electricity, charges. After charging is finished, the quick charging relay is controlled to be disconnected, so that the charging port is electrically disconnected with the battery. The power battery is provided with a positive electrode and a negative electrode, and the corresponding quick charge relay also comprises a quick charge positive relay for controlling the on-off of the positive electrode charging port and the positive electrode of the battery and a quick charge negative relay for controlling the on-off of the negative electrode charging port and the negative electrode of the battery.
Relays may fail, such as by controlling the relay to close, to not close properly, or to open improperly, which requires the relay status to be checked. Two detection methods are currently used: a relay auxiliary contact method and a voltage acquisition method. The auxiliary contact mode needs a specially-made relay, the cost is relatively high, and the adhesion detection mode is limited by the relay and is not popularized and applied. A more common approach is voltage acquisition.
For example, patent publication No. CN 102162833 a discloses a method for detecting the operating state of a relay in a high-voltage loop of an electric vehicle, which respectively collects voltages at two ends of a positive relay and a negative relay, collects voltages at two ends of a battery pack, and determines the operating states of the positive relay and the negative relay according to whether the voltage values can be collected. The method judges the working state of the relay according to whether the voltage value can be acquired or not, has certain error and cannot detect the low-side relay. The invention is achieved accordingly.
Disclosure of Invention
1. Objects of the invention
Aiming at the existing technical problems, the state detection method, the isolation detection circuit and the equipment of the electric vehicle relay are provided, the voltages of four ports, namely power battery voltage +, power battery voltage-, charging + and charging-are sampled respectively, the four sampling voltages are combined in pairs, and the combined result is judged to determine the state of the quick-charging relay, so that the detection accuracy is greatly improved, the low-side relay can be detected, the safety is high, and the cost is low.
2. The technical scheme adopted by the invention
The utility model provides an electric automobile relay's isolation detection circuitry, includes four sampling circuit, sampling circuit sets up respectively at power battery positive negative pole both ends and charge mouthful positive negative pole both ends, obtains Vbatt +, Vbatt-, Vchg +, Vchg-four sampling voltage, makes up these four sampling voltage two double-phase, respectively through first solid state relay and second solid state relay, and the signal that obtains passes through the processor processing, judges the operating condition of positive relay and negative relay through the voltage difference of different adoption voltages.
In the preferred technical scheme, signals obtained through the first solid-state relay and the second solid-state relay are input into an analog-digital conversion chip and then processed through a processor.
In a preferred technical scheme, the first solid-state relay, the second solid-state relay and the analog-to-digital conversion chip are connected with an isolation power supply.
In a preferred technical solution, the determining the working states of the positive relay and the negative relay by the voltage difference of different applied voltages includes:
when the positive relay is closed, if the voltage difference between Vbatt + and Vchg + is greater than or equal to a threshold value, judging the high-resistance state fault of the positive relay, otherwise, judging the positive relay to be normal; when the positive relay is disconnected, if the voltage difference between Vbatt + and Vchg + is smaller than a threshold value, judging that the positive relay is in adhesion fault, otherwise, judging that the positive relay is normal;
when the negative relay is closed, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is larger than or equal to a threshold value, judging the high-resistance state fault of the negative relay, otherwise, judging the fault to be normal; and when the negative relay is disconnected, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is smaller than a threshold value, judging that the negative relay is in adhesion fault, otherwise, judging that the negative relay is normal.
The invention also discloses a state detection method of the electric automobile relay, which comprises the following steps:
s01: respectively sampling positive and negative electrode voltages of a power battery and positive and negative electrode voltages of a charging port to obtain four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-;
s02: combining and comparing the obtained four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-;
s03: and judging the working states of the positive relay and the negative relay by adopting the voltage difference of different voltages.
In a preferred embodiment, the step S03 includes: when the positive relay is closed, if the voltage difference between Vbatt + and Vchg + is greater than or equal to a threshold value, judging the high-resistance state fault of the positive relay, otherwise, judging the positive relay to be normal; when the positive relay is disconnected, if the voltage difference between Vbatt + and Vchg + is smaller than a threshold value, judging that the positive relay is in adhesion fault, otherwise, judging that the positive relay is normal;
when the negative relay is closed, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is larger than or equal to a threshold value, judging the high-resistance state fault of the negative relay, otherwise, judging the fault to be normal; and when the negative relay is disconnected, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is smaller than a threshold value, judging that the negative relay is in adhesion fault, otherwise, judging that the negative relay is normal.
The invention also discloses an isolation detection device of the electric automobile relay, which comprises the isolation detection circuit of the electric automobile relay.
3. Advantageous effects adopted by the present invention
The invention samples the voltages of four ports, namely the voltage + of the power battery, the voltage-of the power battery, the voltage + of the charge battery and the voltage-of the charge battery respectively, combines the four sampling voltages in pairs, and judges the combination result to determine the state of the quick charge relay, thereby greatly improving the detection accuracy, being capable of detecting the low-side relay without signal isolation, having high safety and low cost. The problems of high cost, large error and poor safety of the quick charging relay in the prior art are solved.
Drawings
FIG. 1 is a sampling schematic block diagram of an isolation detection circuit of an electric vehicle relay of the present invention;
FIG. 2 is a schematic diagram of a detection circuit of the isolation detection circuit of the electric vehicle relay of the present invention;
FIG. 3 is a flow chart of a method for detecting the state of an electric vehicle relay according to the present invention.
Detailed Description
The technical solutions in the examples of the present invention are clearly and completely described below with reference to the drawings in the examples of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without inventive step, are within the scope of the present invention.
The present invention will be described in further detail with reference to the accompanying drawings.
Example 1
As shown in fig. 1 and 2, an isolation detection circuit for an electric vehicle relay includes four sampling circuits, the sampling circuits are respectively disposed at two ends of a positive electrode and a negative electrode of a power battery and at two ends of a positive electrode and a negative electrode of a charging port to obtain four sampling voltages Vbatt +, Vbatt-, Vchg + and Vchg-.
The sampling circuit may be an existing conventional sampling circuit, and is not described herein.
The invention samples the voltages of four ports, namely the voltage + of the power battery, the voltage-of the power battery, the voltage + of the charge battery and the voltage-of the charge battery respectively, combines the four sampling voltages in pairs, and judges the combination result to determine the state of the quick charge relay, thereby greatly improving the detection accuracy, being capable of detecting the low-side relay without signal isolation, having high safety and low cost.
In a preferred embodiment, the signals obtained by the first solid-state relay and the second solid-state relay are input into an analog-to-digital conversion chip and then processed by a processor.
In a preferred embodiment, the first solid-state relay, the second solid-state relay and the analog-to-digital conversion chip are connected with an isolated power supply. The isolation power supply isolates the power ground wire between the two solid-state relays and the ADC, and ensures that each module supplies power independently and works independently without mutual interference.
In a preferred embodiment, the determining the working states of the positive relay and the negative relay according to the voltage difference between different applied voltages includes:
when the positive relay is closed, if the voltage difference between Vbatt + and Vchg + is greater than or equal to a threshold value, judging the high-resistance state fault of the positive relay, otherwise, judging the positive relay to be normal; when the positive relay is disconnected, if the voltage difference between Vbatt + and Vchg + is smaller than a threshold value, judging that the positive relay is in adhesion fault, otherwise, judging that the positive relay is normal;
when the negative relay is closed, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is larger than or equal to a threshold value, judging the high-resistance state fault of the negative relay, otherwise, judging the fault to be normal; and when the negative relay is disconnected, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is smaller than a threshold value, judging that the negative relay is in adhesion fault, otherwise, judging that the negative relay is normal.
In another embodiment, as shown in fig. 3, the invention further discloses a method for detecting the state of the relay of the electric vehicle, which comprises the following steps:
s01: respectively sampling positive and negative electrode voltages of a power battery and positive and negative electrode voltages of a charging port to obtain four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-;
s02: combining and comparing the obtained four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-;
s03: and judging the working states of the positive relay and the negative relay by adopting the voltage difference of different voltages.
In a preferred embodiment, the step S03 includes: when the positive relay is closed, if the voltage difference between Vbatt + and Vchg + is greater than or equal to a threshold value, judging the high-resistance state fault of the positive relay, otherwise, judging the positive relay to be normal; when the positive relay is disconnected, if the voltage difference between Vbatt + and Vchg + is smaller than a threshold value, judging that the positive relay is in adhesion fault, otherwise, judging that the positive relay is normal;
when the negative relay is closed, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is larger than or equal to a threshold value, judging the high-resistance state fault of the negative relay, otherwise, judging the fault to be normal; and when the negative relay is disconnected, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is smaller than a threshold value, judging that the negative relay is in adhesion fault, otherwise, judging that the negative relay is normal.
In another embodiment, the invention further discloses an isolation detection device of an electric vehicle relay, which comprises the isolation detection circuit of the electric vehicle relay.
The following is a specific example, as shown in fig. 1 and 2:
BT1 is a vehicle-mounted power battery having two electrodes, positive and negative. Charge + and CHARGE-are the positive and negative electrodes of the charging port, respectively. Relay1 is a charging positive Relay, and Relay2 is a charging positive Relay. And the positive pole and the negative pole of the charging port are respectively connected with the vehicle-mounted power battery through the charging positive relay and the charging positive relay. Of course, this is a simple connection method, and other circuits may be provided between the charging port and the battery in reality.
And sampling the positive and negative electrode voltages of the power battery and the positive and negative electrode voltages of the charging port to respectively obtain four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-. The four voltages are combined in pairs, the four voltages respectively pass through the solid-state relay1 and the solid-state relay2, the obtained signals are input into an analog-digital conversion chip, and then the signals are transmitted to a single chip microcomputer to be read, so that the state of the relay can be obtained. The isolation power supply in the diagram isolates the power ground wires between the two solid-state relays and the ADC, and ensures that each module supplies power independently and works independently without mutual interference.
By controlling the solid-state relay1, the signal output to the IN1 port can be set to Vchg + or Vchg-;
by controlling solid state relay2, the signal output to port IN2 can be set to either Vbatt + or Vbatt-;
whether the states of the positive quick-charge relay and the negative quick-charge relay are normal or abnormal is judged through different combinations of input voltages of ports IN1 and IN 2.
The specific judging method comprises the following steps:
when the Relay of Relay1 is closed, the pressure difference between Vbatt + (the voltage between the Relay1-1 port and the CHARGE-) and Vchg + (the voltage between the Relay1-2 port and the CHARGE-) is more than 10V, and the Relay1 is judged to have high-resistance fault, otherwise, the Relay is normal; when the Relay of Relay1 is disconnected, the pressure difference between Vbatt + and Vchg + is less than 10V, and the Relay of Relay1 is judged to be in adhesion fault, otherwise, the Relay is normal.
When the Relay2 is closed, the pressure difference between Vbatt and Vchg is more than 10V, namely the Relay2 has high-resistance state fault, otherwise, the Relay is normal; when the Realy2 Relay is disconnected, the pressure difference between Vbatt and Vchg is smaller than 10V, the Relay adhesion fault of Relay2 is judged, and otherwise, the Relay adhesion fault is normal.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (7)
1. The isolation detection circuit of the electric vehicle relay is characterized by comprising four sampling circuits, wherein the sampling circuits are respectively arranged at two ends of a positive electrode and a negative electrode of a power battery and two ends of a positive electrode and a negative electrode of a charging port to obtain four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-, two sampling voltages are combined, the four sampling voltages respectively pass through a first solid-state relay and a second solid-state relay, the obtained signals are processed by a processor, and the working states of the positive electrode relay and the negative electrode relay are judged by voltage differences of different adopted voltages.
2. The isolation detection circuit of the electric vehicle relay according to claim 1, wherein the signals obtained through the first solid-state relay and the second solid-state relay are input into an analog-to-digital conversion chip and then processed by the processor.
3. The isolation detection circuit of the electric vehicle relay according to claim 2, wherein the first solid-state relay, the second solid-state relay and the analog-to-digital conversion chip are connected with an isolation power supply.
4. The isolation detection circuit of the electric vehicle relay according to claim 3, wherein the determining the working states of the positive relay and the negative relay by the voltage difference of different applied voltages comprises:
when the positive relay is closed, if the voltage difference between Vbatt + and Vchg + is greater than or equal to a threshold value, judging the high-resistance state fault of the positive relay, otherwise, judging the positive relay to be normal; when the positive relay is disconnected, if the voltage difference between Vbatt + and Vchg + is smaller than a threshold value, judging that the positive relay is in adhesion fault, otherwise, judging that the positive relay is normal;
when the negative relay is closed, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is larger than or equal to a threshold value, judging the high-resistance state fault of the negative relay, otherwise, judging the fault to be normal; and when the negative relay is disconnected, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is smaller than a threshold value, judging that the negative relay is in adhesion fault, otherwise, judging that the negative relay is normal.
5. A state detection method of an electric automobile relay is characterized by comprising the following steps:
s01: respectively sampling positive and negative electrode voltages of a power battery and positive and negative electrode voltages of a charging port to obtain four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-;
s02: combining and comparing the obtained four sampling voltages of Vbatt +, Vbatt-, Vchg + and Vchg-;
s03: and judging the working states of the positive relay and the negative relay by adopting the voltage difference of different voltages.
6. The method for detecting the state of the electric vehicle relay according to claim 5, wherein the step S03 includes: when the positive relay is closed, if the voltage difference between Vbatt + and Vchg + is greater than or equal to a threshold value, judging the high-resistance state fault of the positive relay, otherwise, judging the positive relay to be normal; when the positive relay is disconnected, if the voltage difference between Vbatt + and Vchg + is smaller than a threshold value, judging that the positive relay is in adhesion fault, otherwise, judging that the positive relay is normal;
when the negative relay is closed, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is larger than or equal to a threshold value, judging the high-resistance state fault of the negative relay, otherwise, judging the fault to be normal; and when the negative relay is disconnected, if the voltage difference between Vbatt & lt- & gt and Vchg & lt- & gt is smaller than a threshold value, judging that the negative relay is in adhesion fault, otherwise, judging that the negative relay is normal.
7. An isolation detection device of an electric vehicle relay, characterized by comprising the isolation detection circuit of the electric vehicle relay according to any one of claims 1 to 4.
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| CN202111473333.2A CN114280470A (en) | 2021-12-02 | 2021-12-02 | State detection method, isolation detection circuit and equipment for electric vehicle relay |
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| CN202111473333.2A CN114280470A (en) | 2021-12-02 | 2021-12-02 | State detection method, isolation detection circuit and equipment for electric vehicle relay |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116298833A (en) * | 2022-09-06 | 2023-06-23 | 肇庆小鹏汽车有限公司 | Relay adhesion detection method and system, storage medium and new energy automobile |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101718842A (en) * | 2009-12-11 | 2010-06-02 | 北汽福田汽车股份有限公司 | Monitoring method and monitoring system for touch switch |
| CN205941816U (en) * | 2016-07-07 | 2017-02-08 | 河北深海电器有限公司 | Detect circuit of high -pressure contactor contact state |
| CN110763990A (en) * | 2019-11-05 | 2020-02-07 | 骆驼集团武汉光谷研发中心有限公司 | Diagnosis method for relay of new energy automobile |
| WO2020031779A1 (en) * | 2018-08-06 | 2020-02-13 | カルソニックカンセイ株式会社 | Switch unit and battery device |
| CN112798946A (en) * | 2020-12-29 | 2021-05-14 | 东风汽车有限公司 | Detection method of electric vehicle quick charge relay detection circuit and detection electronic equipment |
-
2021
- 2021-12-02 CN CN202111473333.2A patent/CN114280470A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101718842A (en) * | 2009-12-11 | 2010-06-02 | 北汽福田汽车股份有限公司 | Monitoring method and monitoring system for touch switch |
| CN205941816U (en) * | 2016-07-07 | 2017-02-08 | 河北深海电器有限公司 | Detect circuit of high -pressure contactor contact state |
| WO2020031779A1 (en) * | 2018-08-06 | 2020-02-13 | カルソニックカンセイ株式会社 | Switch unit and battery device |
| CN110763990A (en) * | 2019-11-05 | 2020-02-07 | 骆驼集团武汉光谷研发中心有限公司 | Diagnosis method for relay of new energy automobile |
| CN112798946A (en) * | 2020-12-29 | 2021-05-14 | 东风汽车有限公司 | Detection method of electric vehicle quick charge relay detection circuit and detection electronic equipment |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116298833A (en) * | 2022-09-06 | 2023-06-23 | 肇庆小鹏汽车有限公司 | Relay adhesion detection method and system, storage medium and new energy automobile |
| CN116298833B (en) * | 2022-09-06 | 2024-03-08 | 肇庆小鹏汽车有限公司 | Relay adhesion detection method and system, storage medium and new energy automobile |
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