CN115267519A - Adhesion detection method for electric vehicle quick-charging relay - Google Patents

Abstract

The invention belongs to the technical field of automobiles, and particularly relates to an adhesion detection method for a quick charge relay of an electric automobile. The method comprises the following steps: step one, a PDU controller samples voltages at V1 and V2 points at two ends of a relay through a resistor, an isolation power supply and an isolation ADC to carry out logic judgment; step two, judging the state of the relay; step three: and the PDU controller reports the state or voltage of the quick charge relay, and the BMS detects whether the quick charge relay is adhered or not. The method can quickly and accurately judge the relay adhesion or open circuit fault, ensure the safe use of the whole vehicle and provide a design basis for the subsequent quick-charging adhesion detection and road testing development.

Description

Adhesion detection method for electric vehicle quick-charging relay

Technical Field

The invention belongs to the technical field of automobiles, and particularly relates to an adhesion detection method for a quick charge relay of an electric automobile.

Background

Direct current quick charging is a main charging mode of an electric automobile, in a direct current quick charging loop, both voltage and current are large, and a quick charging relay is usually used between a battery end and a charging port to control the on-off of a circuit. When charging, the charging gun is electrically connected with a charging port of the electric automobile, then the quick charging relay is controlled to be closed, so that the charging port is communicated with the battery to be charged, and after charging is finished, the quick charging relay is controlled to be disconnected, so that the charging port is disconnected with the battery. The quick charge relay may fail, for example, by not closing properly when it is controlled to close, or by not opening properly when it is controlled to open. For this reason, the quick charge relay needs to be detected. Under the condition that the adhesion takes place at the relay that fills soon, can lead to filling mouthful area high voltage electricity soon, still can lead to the unable normal use of the strategy of charging when causing the electric shock risk, cause unable charging.

Disclosure of Invention

The invention provides an adhesion detection method for a quick charge relay of an electric vehicle, which can quickly and accurately judge the adhesion or open circuit fault of the relay, ensure the safe use of the whole vehicle and provide a design basis for the subsequent detection and path detection development of quick charge adhesion.

The technical scheme of the invention is described as follows by combining the attached drawings:

an adhesion detection method for a quick charge relay of an electric automobile comprises the following steps:

step one, a PDU controller samples voltages at V1 and V2 points at two ends of a relay through a resistor, an isolation power supply and an isolation ADC to carry out logic judgment;

step two, judging the state of the relay;

step three: and the PDU controller reports the state or voltage of the quick charge relay, and the BMS detects whether the quick charge relay is adhered or not.

Further, the specific method of the second step is as follows:

when the voltage value V2 of the V1 point V1-V2 point is detected to be less than 60V +/-5V, after the detection lasts for 300ms, the report closing is confirmed; when the voltage value V2 of the V1 point V1-V2 point is detected to be more than 80V +/-5V, reporting to be disconnected after the time lasts for 100 ms; and reporting signals of the on and off of the relay by the PDU controller.

Further, in the third step, the BMS detects the time:

(a) When the main loop is under high voltage, the main positive relay is closed;

(b) After the quick charging is finished, after the quick charging relay is disconnected, before the main relay is disconnected;

the detection method of the BMS detection state value comprises the following steps:

the BMS judges whether the relay has a fault according to the current instruction of the quick charge relay and the open and closed states of the relay reported by the PDU, when the current instruction of the quick charge relay is the same as the reported state of the PDU, the relay is normal, otherwise, the relay is abnormal, and the fault is reported;

(a) And if the current instruction of the quick charge relay is off and the PDU reporting state is on, judging the relay adhesion fault.

(b) If the current instruction of the quick charge relay is closed and the PDU reporting state is open, the open-circuit fault of the relay is judged;

the detection method of the BMS detection voltage value comprises the following steps:

the BMS judges whether the relay has a fault according to the current command of the quick charge relay and the voltage value reported by the PDU, firstly, the BMS carries out logic calculation according to the voltage value reported by the PDU to obtain the open or closed state of the relay, then, the calculated state value of the relay is compared with the current command of the relay, when the current command of the quick charge relay is the same as the reported state of the PDU, the relay is normal, otherwise, the relay is abnormal, and the fault is reported;

(a) If the current command of the quick charging relay is off and the relay state calculated by the BMS is on, judging the relay adhesion fault;

(b) And if the current command of the quick charge relay is closed and the relay state calculated by the BMS is open, judging the open-circuit fault of the relay.

The beneficial effects of the invention are as follows:

the PDU controller reports the state or voltage of the quick-charge relay, and the BMS detects whether the quick-charge relay is adhered or not.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic diagram of an adhesion detection circuit.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the present invention, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation that the first and second features are not in direct contact, but are in contact via another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. "beneath," "under" and "beneath" a first feature includes the first feature being directly beneath and obliquely beneath the second feature, or simply indicating that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

An adhesion detection method for a quick charge relay of an electric automobile comprises the following steps:

step one, the schematic diagram of an adhesion detection circuit is shown in figure 1, a PDU controller samples voltages at V1 and V2 points at two ends of a relay through a resistor, an isolation power supply and an isolation ADC to carry out logic judgment;

and step two, judging the state of the relay according to the detection logic table of the table 1 by using the voltage values of the points V1 and V2 collected in the figure 1, and closing or opening the relay.

TABLE 1

When the voltage value V2 of the V1 point-V2 point is detected to be less than 60V +/-5V, after the detection lasts for 300ms, the report is confirmed to be closed; when the voltage value V2 of the V1 point V1-V2 point is detected to be more than 80V +/-5V, reporting to be disconnected after the time lasts for 100 ms; and the signals of the on and off of the relay are reported by the PDU controller.

And step three, the PDU controller defines and outputs a relay state signal according to the relay state signal of the table 2, the BMS judges whether the relay has adhesion or open circuit faults or not according to the signal and the actual closed state of the relay, and if the current instruction of the quick-charging relay is off and the relay state calculated by the BMS is closed, the adhesion fault of the relay is judged. And if the current command of the quick charge relay is closed and the relay state calculated by the BMS is open, judging the open-circuit fault of the relay. If the vehicle is stuck, the vehicle reports the sticking fault, and the vehicle is prohibited from being charged quickly, so that the safety of the vehicle is ensured.

TABLE 2

PDU controller defines output relay voltage signal according to the relay voltage signal of table 3, and BMS judges whether the relay has adhesion or open circuit trouble according to this voltage signal and the detection logic table of table 1, if the present instruction of quick charge relay is the disconnection, and the relay state that BMS calculated is closed, then judges relay adhesion trouble. And if the current command of the quick charge relay is closed and the relay state calculated by the BMS is open, judging the open-circuit fault of the relay. If the vehicle is stuck, the sticking fault is reported, the vehicle is forbidden to be charged quickly, and the vehicle safety is ensured.

TABLE 3

In conclusion, the PDU controller reports the state or voltage of the quick charge relay, the BMS detects whether the quick charge relay is adhered or not, the strategy can quickly and accurately judge the adhesion or open circuit fault of the relay, and the safe use of the whole vehicle is guaranteed.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the scope of the present invention is not limited to the specific details of the above embodiments, and any person skilled in the art can substitute or change the technical solution of the present invention and its inventive concept within the technical scope of the present invention, and these simple modifications belong to the scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims (3)

1. The adhesion detection method of the electric automobile quick charge relay is characterized by comprising the following steps of:

step one, a PDU controller samples voltages at V1 and V2 points at two ends of a relay through a resistor, an isolation power supply and an isolation ADC to carry out logic judgment;

step two, judging the state of the relay;

step three: and the PDU controller reports the state or voltage of the quick charge relay, and the BMS detects whether the quick charge relay is adhered or not.

2. The method for detecting the adhesion of the quick charge relay of the electric vehicle as claimed in claim 1, wherein the specific method in the second step is as follows:

when the voltage value V2 of the V1 point V1-V2 point is detected to be less than 60V +/-5V, after the detection lasts for 300ms, the report closing is confirmed; when the voltage value V2 of the V1 point V1-V2 point is detected to be more than 80V +/-5V, reporting to be disconnected after the time lasts for 100 ms; and reporting signals of the on and off of the relay by the PDU controller.

3. The method for detecting the adhesion of the quick charge relay of the electric automobile according to claim 1, wherein in the third step, the BMS detection time is as follows:

(a) When the main circuit is in high voltage, the main positive relay is closed;

(b) After the quick charging is finished, after the quick charging relay is disconnected, before the main relay is disconnected;

the detection method of the BMS detection state value comprises the following steps:

the BMS judges whether the relay has a fault according to the current instruction of the quick charge relay and the open and closed states of the relay reported by the PDU, when the current instruction of the quick charge relay is the same as the reported state of the PDU, the relay is normal, otherwise, the relay is abnormal, and the fault is reported;

(a) And if the current command of the quick charge relay is off and the PDU reporting state is on, judging the relay adhesion fault.

(b) If the current instruction of the quick charge relay is closed and the PDU reporting state is open, judging the open-circuit fault of the relay;

the detection method of the BMS detection voltage value comprises the following steps:

the BMS judges whether the relay has a fault according to the current command of the quick charge relay and the voltage value reported by the PDU, firstly, the BMS carries out logic calculation according to the voltage value reported by the PDU to obtain the open or closed state of the relay, then, the calculated state value of the relay is compared with the current command of the relay, when the current command of the quick charge relay is the same as the reported state of the PDU, the relay is normal, otherwise, the relay is abnormal, and the fault is reported;

(a) If the current command of the quick charging relay is off and the relay state calculated by the BMS is on, judging the relay adhesion fault;

(b) And if the current command of the quick charge relay is closed and the relay state calculated by the BMS is open, judging the open-circuit fault of the relay.

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