CN-121454307-B - Relay adhesion detection method and device, battery management system and battery equipment

CN121454307BCN 121454307 BCN121454307 BCN 121454307BCN-121454307-B

Abstract

The application relates to a relay adhesion detection method, a device, a battery management system and battery equipment, wherein a first relay and a second relay are triggered to be turned off, and under the condition of controlling the switching actions of the first insulation detection circuit and the second insulation detection circuit, if the abrupt change of the sampling voltage following the switching action is detected, the second relay is considered to be truly turned off. If the fact that the sampling voltage does not follow the switch to generate mutation is detected, the sampling voltage and the preset voltage range are further combined, and whether the second relay generates a detection result of adhesion or not is determined. According to the scheme, the first insulation detection circuit and the second insulation detection circuit are controlled to act in a switching mode, so that the sampling voltage of the second relay is suddenly changed when the second relay is not adhered, and the preset voltage range is jumped out. The phenomenon that the second relay is adhered due to the fact that the equivalent capacitor connected to the load at the load end of the relay is not completely used for discharging voltage can be effectively relieved, the second sampling circuit is used for dividing the voltage to obtain the discharging voltage, and the phenomenon that the second relay is adhered is misreported can be effectively relieved.

Inventors

CHEN HUI
Guo Maobai
YE FUMING
ZHONG JINYU

Assignees

宁德时代润智软件科技有限公司
宁德时代新能源科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260108

Claims (15)

1. A relay adhesion detection method, the method comprising: Under the condition that the first relay and the second relay are triggered to be turned off, the first insulation detection circuit and the second insulation detection circuit are controlled to be switched on and turned off, and the second sampling circuit is maintained to be turned on; the battery end of the first relay is connected with the first end of the first insulation detection circuit and the first pole of the battery, the battery end of the second relay is connected with the first end of the second insulation detection circuit and the second pole of the battery, the second end of the first insulation detection circuit and the second end of the second insulation detection circuit are grounded, the load end of the first relay is connected with the first pole of the reference source through a first sampling circuit, the load end of the second relay is connected with the first pole of the reference source through a second sampling circuit, the battery end of the first relay is also connected with the first pole of the reference source through a third sampling circuit, and the battery end of the second relay is also connected with the second pole of the reference source; Determining that the second relay is not adhered under the condition that the voltage change rate of the sampling voltage of the second sampling circuit exceeds a preset change threshold value along with the switching action; And under the condition that the voltage change rate of the sampling voltage does not exceed a preset change threshold along with the switching action, determining the adhesion detection result of the second relay according to the sampling voltage and a preset voltage range.
2. The relay adhesion detection method of claim 1, wherein controlling the switching of the first insulation detection circuit and the second insulation detection circuit and maintaining the second sampling circuit on in the case that the first relay and the second relay are triggered to be turned off comprises: under the condition that the first relay and the second relay are triggered to be turned off, a preliminary result of relay adhesion detection is obtained; and under the condition that the preliminary result comprises the adhesion of the second relay, controlling the first insulation detection circuit and the second insulation detection circuit to act in a switching way, and maintaining the conduction of the second sampling circuit.
3. The relay adhesion detection method of claim 1, wherein controlling switching of the first insulation detection circuit and the second insulation detection circuit comprises: and cutting off the connection between the first insulation detection circuit and the battery end of the first relay and the connection between the second insulation detection circuit and the battery end of the second relay.
4. The relay adhesion detection method according to claim 1, wherein the first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel, a structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch, the second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel, and a structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch; the control of the switching actions of the first insulation detection circuit and the second insulation detection circuit comprises the following steps: controlling the first main switch and the second main switch to be conducted, controlling the first bridge arm circuit to be conducted, and maintaining the second bridge arm to be turned off; Or, controlling the first main switch and the second main switch to be conducted, controlling the second bridge arm circuit to be conducted, and maintaining the first bridge arm to be turned off.
5. The relay adhesion detection method according to claim 1, wherein the first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel, a structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch, the second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel, and a structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch; the control of the switching actions of the first insulation detection circuit and the second insulation detection circuit comprises the following steps: And under the condition that the first sampling circuit is turned off, the first main switch, the second main switch and the second sampling circuit are kept on, and the first bridge arm circuit and the second bridge arm circuit are controlled to be switched on.
6. The relay adhesion detection method of claim 5, wherein the controlling the switching actions of the first leg circuit and the second leg circuit comprises: Controlling the first bridge arm circuit to be conducted, and maintaining the second bridge arm circuit to be turned off; or controlling the second bridge arm circuit to be conducted, and maintaining the first bridge arm circuit to be turned off.
7. The relay adhesion detection method of claim 5, wherein the controlling the switching actions of the first leg circuit and the second leg circuit comprises: Under the condition of controlling the conduction set time length of the first bridge arm circuit, the first bridge arm circuit is turned off, and the second bridge arm circuit is controlled to be conducted; Or under the condition of controlling the conduction set time length of the second bridge arm circuit, the second bridge arm circuit is turned off, and the first bridge arm circuit is controlled to be conducted.
8. The relay adhesion detection method of claim 5, wherein the controlling the switching actions of the first leg circuit and the second leg circuit comprises: The first bridge arm circuit is controlled to be periodically switched on and off to operate, and the second bridge arm circuit is maintained to be switched off; Or, controlling the second bridge arm circuit to periodically switch on and off to operate, and maintaining the first bridge arm circuit to switch off.
9. The relay adhesion detection method according to claim 1, wherein the first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel, a structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch, the second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel, and a structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch; the control of the switching actions of the first insulation detection circuit and the second insulation detection circuit comprises the following steps: controlling the first main switch and the first bridge arm circuit to be conducted, and turning off the second main switch and the second bridge arm circuit; or, controlling the second main switch and the second bridge arm circuit to be conducted, and switching off the first main switch and the first bridge arm circuit.
10. The relay adhesion detection method according to any one of claims 1 to 9, wherein determining the adhesion detection result of the second relay according to the sampling voltage and a preset voltage range includes: Determining that the second relay is adhered under the condition that the preset adhesion condition is met according to the sampling voltage and the preset voltage range; and under the condition that the preset adhesion condition is not met according to the sampling voltage and the preset voltage range, determining that the second relay is not adhered.
11. The relay adhesion detection method of claim 10, further comprising: And determining that the preset adhesion condition is met under the condition that the first duration of the sampling voltage in the preset voltage range reaches the first preset duration.
12. The relay adhesion detection method of claim 10, further comprising: acquiring a first ground voltage of the first insulation detection circuit and a second ground voltage of the second insulation detection circuit; determining a voltage ratio of the first ground voltage to the second ground voltage; and determining that the preset adhesion condition is met when the first duration of the sampling voltage in the preset voltage range reaches a first preset duration, and the second duration of the voltage ratio smaller than the preset ratio reaches a second preset duration within a preset interval of the first duration.
13. A relay adhesion detection apparatus, the apparatus comprising: the switch control component is used for controlling the first insulation detection circuit and the second insulation detection circuit to switch on and keep the second sampling circuit on under the condition that the first relay and the second relay are triggered to be turned off, wherein the battery end of the first relay is connected with the first end of the first insulation detection circuit and the first pole of the battery, the battery end of the second relay is connected with the first end of the second insulation detection circuit and the second pole of the battery, the second end of the first insulation detection circuit and the second end of the second insulation detection circuit are grounded, the load end of the first relay is connected with the first pole of the reference source through the first sampling circuit, the load end of the second relay is connected with the first pole of the reference source through the second sampling circuit, the battery end of the first relay is also connected with the first pole of the reference source through the third sampling circuit, and the battery end of the second relay is also connected with the second pole of the reference source; The follow-up checking component is used for determining that the second relay is not adhered under the condition that the voltage change rate of the sampling voltage of the second sampling circuit and the follow-up switching action exceed a preset change threshold value; And the adhesion detection component is used for determining an adhesion detection result of the second relay according to the sampling voltage and a preset voltage range under the condition that the voltage change rate of the sampling voltage does not exceed a preset change threshold along with the switching action.
14. The battery management system is characterized by comprising a reference source, a first relay, a second relay, a first sampling circuit, a second sampling circuit, a third sampling circuit, a first insulation detection circuit, a second insulation detection circuit and a controller; The two ends of the first sampling circuit are respectively connected with the load end of the first relay and the first pole of the reference source, the two ends of the second sampling circuit are respectively connected with the load end of the second relay and the first pole of the reference source, the battery end of the first relay is also connected with the first pole of the reference source through the third sampling circuit, the battery end of the second relay is also connected with the second pole of the reference source, the first insulation detection circuit is connected with the battery and the battery end of the first relay, the second insulation detection circuit is connected with the battery and the battery end of the second relay, the load end of the first relay and the load end of the second relay are also connected with an electric load, and the first insulation detection circuit and the second insulation detection circuit are grounded; the first relay, the second relay, the first sampling circuit, the second sampling circuit, the first insulation detection circuit, and the second insulation detection circuit are respectively connected to the controller, and the controller is configured to execute the steps of the relay adhesion detection method according to any one of claims 1 to 12.
15. A battery device comprising a battery and the battery management system of claim 14.

Description

Relay adhesion detection method and device, battery management system and battery equipment Technical Field The present application relates to the field of battery technologies, and in particular, to a relay adhesion detection method and apparatus, a battery management system, and a battery device. Background With the rapid development of new energy technology, secondary batteries represented by lithium batteries are gradually applied to various fields such as energy storage systems, electric vehicles, aerospace and the like, and great electricity utilization convenience is brought to daily production and life of people. The Battery management system (Battery MANAGEMENT SYSTEM, BMS) is a core component for monitoring, protecting and managing the Battery, and the relay of the Battery management system is used as a key executive component, and the reliable on-off of the relay is directly related to the safe operation of the load. However, in the related art, when the relay of the battery management system is detected to be on-off, a phenomenon of erroneous judgment and sticking easily occurs. Disclosure of Invention Based on the above, it is necessary to provide a relay adhesion detection method, a device, a battery management system and a battery device, so as to alleviate the phenomenon of erroneous judgment of adhesion during relay on-off detection and improve the adhesion recognition accuracy of the relay. According to the method, under the condition that a first relay and a second relay are triggered to be turned off, a first insulation detection circuit and a second insulation detection circuit are controlled to operate, and a second sampling circuit is maintained to be conducted, wherein a battery end of the first relay is connected with the first insulation detection circuit and a battery, a battery end of the second relay is connected with the second insulation detection circuit and the battery, a load end of the first relay is connected with a first pole of a reference source through the first sampling circuit, a load end of the second relay is connected with the first pole of the reference source through the second sampling circuit, a battery end of the first relay is also connected with the first pole of the reference source through a third sampling circuit, a battery end of the second relay is also connected with a second pole of the reference source, a voltage change rate of sampling voltage of the second sampling circuit is grounded, the voltage change rate of the second sampling circuit is not determined to be beyond a preset voltage change rate under the condition that the voltage is not adhered to the first pole of the reference source, and the voltage change rate of the relay is not adhered to the first pole of the reference source is determined under the preset voltage change rate. According to the relay adhesion detection method, under the condition that the second relay arranged between the reference source and the second sampling circuit is truly turned off, the voltage change rate of the sampling voltage of the second sampling circuit exceeds the preset change threshold value, namely abrupt change occurs, by controlling the switching action of the first insulation detection circuit and the second insulation detection circuit and maintaining the on operation mode of the second sampling circuit, so that the preset voltage range is jumped out. Therefore, when the first relay and the second relay are triggered to be turned off and the control mode is executed, if the abrupt change of the sampling voltage following the switching action is detected, the second relay is considered to be truly turned off, that is, the situation of adhesion does not exist. If the fact that the sampling voltage does not follow the switch to generate mutation is detected, the sampling voltage and the preset voltage range are further combined, and whether the second relay generates a detection result of adhesion or not is determined. According to the scheme, the first insulation detection circuit and the second insulation detection circuit are controlled to operate, and the second sampling circuit is maintained to be conducted, so that the sampling voltage of the second relay is suddenly changed when the second relay is not adhered, and the preset voltage range is jumped out. Therefore, the phenomenon that the second relay is stuck due to false alarm caused by the fact that the equivalent capacitor of the load end of the relay is connected with the load is not completely discharged, and the accuracy of the adhesion identification of the relay is improved. In some embodiments, the step of controlling the first insulation detection circuit and the second insulation detection circuit to switch on and maintain the second sampling circuit to be on under the condition that the first relay and the second relay trigger to be turned off comprises the steps of obtaining a preliminary result of relay adhesion detection under