Relay detection method, device, battery management system, medium and program product

Abstract

The present application provides a relay detection method, device, battery management system, medium and program product, which belong to the field of battery technology. The relay detection method includes controlling a voltage regulation circuit to adjust a first voltage difference when the relay is disconnected, wherein the voltage regulation circuit is configured to change the first voltage difference, and the first voltage difference indicates the voltage difference between the first end of the relay and the first voltage end of the voltage regulation circuit; determining the difference between the first voltage difference and the second voltage difference, wherein the second voltage difference indicates the voltage difference between the second end of the relay and the first voltage end; and determining whether the relay is abnormal based on the difference between the first voltage difference and the second voltage difference. The detection method can accurately determine whether the relay is abnormal and improve the accuracy of the detection result.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a relay detection method, device, battery management system, medium and program product. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] In electric vehicles, there are multiple relays used to control the on and off of each power supply circuit. Diagnostic confirmation of the relay status is crucial for the normal operation of the vehicle. However, during the diagnosis of the relay status, the relay status may be misjudged, affecting the normal use of the electric vehicle. Summary of the invention

[0004] The present application aims to at least solve the technical problem of misjudging the relay state in the background technology. To this end, one purpose of the present application is to provide a relay detection method to improve the accuracy of the relay state detection result and reduce the probability of misjudgment.

[0005] An embodiment of the first aspect of the present application provides a relay detection method, including controlling a voltage regulation circuit to adjust a first voltage difference when the relay is disconnected, wherein the voltage regulation circuit is configured to change the first voltage difference, and the first voltage difference indicates a voltage difference between a first end of the relay and a first voltage end of the voltage regulation circuit; determining a difference between the first voltage difference and a second voltage difference, wherein the second voltage difference indicates a voltage difference between a second end of the relay and the first voltage end; and determining whether the relay is abnormal based on the difference between the first voltage difference and the second voltage difference.

[0006] In the technical solution of the embodiment of the present application, when the relay is disconnected, the voltage regulating circuit is used to adjust the difference between the first voltage difference and the second voltage difference between the two ends of the relay and the first voltage end, thereby reducing the influence of the peripheral circuit connected to the relay on the voltage at the two ends of the relay. By judging the difference between the first voltage difference and the second voltage difference, it is possible to accurately determine whether the relay is abnormal, thereby improving the accuracy of the detection result.

[0007] In some embodiments, the voltage regulation circuit further includes a reference terminal, and determining the difference between the first voltage difference and the second voltage difference includes: obtaining a third voltage difference, the third voltage difference indicating the voltage difference between the first terminal of the relay and the reference terminal; obtaining a fourth voltage difference, the fourth voltage difference indicating the voltage difference between the reference terminal and the first voltage terminal; summing the third voltage difference and the fourth voltage difference to obtain the first voltage difference; obtaining a fifth voltage difference, the fifth voltage difference indicating the voltage difference between the second terminal of the relay and the reference terminal; summing the fifth voltage difference and the fourth voltage difference to obtain the second voltage difference; and obtaining the difference between the first voltage difference and the second voltage difference based on the first voltage difference and the second voltage difference. The voltage difference between the two terminals of the relay and the reference terminal and the voltage difference between the first voltage terminal and the reference terminal are determined respectively, and the first voltage difference can be changed by changing the voltage difference between the first voltage terminal and the reference terminal, thereby simplifying the detection process.

[0008] In some embodiments, the voltage regulating circuit includes: a first resistor, configured to be connected in series between a reference terminal and a second terminal of the relay; a first voltage regulating circuit, connected in parallel with the first resistor, including at least one switch, and configured to change the first voltage difference by changing the state of at least one switch. By properly setting the voltage regulating circuit, the first voltage difference can be changed, thereby improving the accuracy of the detection result.

[0009] In some embodiments, the voltage regulating circuit includes: a second resistor, configured to be connected in series between the reference terminal and the first voltage terminal; and a second voltage regulating circuit, connected in parallel with the second resistor, including at least one switch, configured to change the first voltage difference by changing the state of at least one switch. By properly setting the voltage regulating circuit, the first voltage difference can be changed, thereby improving the accuracy of the detection result.

[0010] In some embodiments, controlling the voltage regulating circuit to adjust the first voltage difference when the relay is disconnected includes at least one of the following: controlling the first voltage regulating circuit to change the state of at least one switch in the first voltage regulating circuit; controlling the second voltage regulating circuit to change the state of at least one switch in the second voltage regulating circuit. By controlling the switch state in the voltage regulating circuit, the first voltage difference can be changed accordingly, reducing the complexity of the detection process.

[0011] In some embodiments, the first voltage regulating circuit includes a first voltage regulating resistor and a first switch connected in series, the second voltage regulating circuit includes a second voltage regulating resistor and a second switch connected in series, and when the relay is disconnected, controlling the voltage regulating circuit to adjust the first voltage difference includes: in response to the fifth voltage difference being greater than the fourth voltage difference, closing the first switch and opening the second switch; in response to the fifth voltage difference being less than the fourth voltage difference, closing the second switch and opening the first switch; and in response to the fifth voltage difference being equal to the fourth voltage difference, closing either the first switch or the second switch. Based on the values ​​of the fourth voltage difference and the fifth voltage difference, the on and off of the first switch and the second switch are determined, so that the change in the first voltage difference is as large as possible, so that the detection result is more accurate.

[0012] In some embodiments, the relay detection method further includes: determining a ratio of a fifth voltage difference to a fourth voltage difference before controlling the voltage regulation circuit to adjust the first voltage difference when the relay is disconnected; and determining whether the voltage regulation circuit has a fault according to whether the ratio of the fifth voltage difference to the fourth voltage difference satisfies a predetermined voltage condition. Before determining whether the relay is abnormal, first determine whether the voltage regulation circuit has a fault to eliminate the risk of abnormal detection caused by a fault in the voltage regulation circuit.

[0013] In some embodiments, the predetermined voltage condition includes any one of the following: the ratio of the fifth voltage difference to the fourth voltage difference is greater than the ratio of the first threshold resistor to the resistance of the second resistor, and less than the ratio of the resistance of the first resistor to the second threshold resistor; or the ratio of the fifth voltage difference to the fourth voltage difference is greater than the ratio of the third threshold resistor to the resistance of the first resistor, and less than the ratio of the resistance of the second resistor to the fourth threshold resistor. Determining whether the ratio of the fifth voltage difference to the fourth voltage difference falls within a predetermined range can determine whether there is a fault such as a short circuit in the voltage regulation circuit.

[0014] An embodiment of the second aspect of the present application provides a relay detection device, comprising: a first module, used to control a voltage regulation circuit to adjust a first voltage difference when the relay is disconnected, wherein the voltage regulation circuit is configured to change the first voltage difference, and the first voltage difference indicates a voltage difference between a first end of the relay and a first voltage end of the voltage regulation circuit; a second module, used to determine a difference between the first voltage difference and a second voltage difference, wherein the second voltage difference indicates a voltage difference between a second end of the relay and the first voltage end; and a third module, used to determine whether the relay is abnormal based on the difference between the first voltage difference and the second voltage difference.

[0015] An embodiment of the third aspect of the present application provides a battery management system, including: a voltage regulation circuit, the voltage regulation circuit is configured to change a first voltage difference, the first voltage difference indicating a voltage difference between a first end of a relay and a first voltage end of the voltage regulation circuit; at least one processor; and at least one memory communicatively connected to the at least one processor, the at least one memory storing instructions, which, when executed individually or collectively by the at least one processor, enable the battery management system to execute the relay detection method in the above embodiment.

[0016] In some embodiments, the voltage regulating circuit also includes: a reference terminal; a first resistor, configured to be connected in series between the reference terminal and the second terminal of the relay; and a first voltage regulating circuit, connected in parallel with the first resistor, including at least one switch, and configured to change the first voltage difference by changing the state of at least one switch.

[0017] In some embodiments, the voltage regulating circuit also includes: a second resistor, configured to be connected in series between a reference terminal and the first voltage terminal; and a second voltage regulating circuit, connected in parallel with the second resistor, including at least one switch, and configured to change the first voltage difference by changing the state of at least one switch.

[0018] An embodiment of the fourth aspect of the present application provides a computer-readable storage medium storing instructions, which, when executed individually or collectively by at least one processor of the battery management system in the above embodiment, causes the battery management system to execute the relay detection method in the above embodiment.

[0019] An embodiment of the fifth aspect of the present application provides a computer program product, comprising instructions, which, when executed individually or collectively by at least one processor of the battery management system in the above embodiment, enable the battery management system to execute the relay detection method in the above embodiment.

[0020] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0022] Figure 1 A schematic flow chart of a relay detection method according to some embodiments of the present application;

[0023] Figure 2 A schematic diagram of a process for determining a difference between a first voltage difference and a second voltage difference in some embodiments of the present application;

[0024] Figure 3 A schematic diagram of a voltage regulation circuit according to some embodiments of the present application;

[0025] Figure 4 A schematic diagram of a process for adjusting a first voltage difference in some embodiments of the present application;

[0026] Figure 5 A schematic diagram of a process for adjusting a first voltage difference in some embodiments of the present application;

[0027] Figure 6 A schematic diagram of a flow chart of detecting whether a voltage regulating circuit has a fault in some embodiments of the present application;

[0028] Figure 7 A schematic diagram of a relay detection device according to some embodiments of the present application;

[0029] Figure 8 Schematic diagram of a voltage regulation circuit according to some embodiments of the present application. DETAILED DESCRIPTION

[0030] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0032] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0035] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0036] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0039] In electric vehicles, there are multiple relays used to control the on and off of various power supply circuits. Diagnostic confirmation of the relay status is crucial for the normal operation of the vehicle.

[0040] In the prior art, the main method for detecting whether the relay state is abnormal is to detect the voltage difference across the relay to determine whether the relay state is abnormal. After the relay is disconnected, if the voltage difference across the relay remains the same, it is considered that the relay has a fault such as adhesion. However, due to the existence of a peripheral circuit connected to the relay, an equivalent capacitor connected to the relay may exist in the circuit where the relay is located. When the relay is disconnected, since the energy stored in the equivalent capacitor cannot be discharged in time, the voltage across the relay will not change in time and cannot generate a sufficient voltage difference, resulting in an erroneous judgment that the relay is faulty, affecting the normal use of the electric vehicle.

[0041] In order to improve the detection accuracy of the relay state, a voltage regulating circuit connected to the relay can be used to change the first voltage difference between one end of the relay and a certain voltage end, thereby changing the difference between the first voltage difference and the second voltage difference between the two ends of the relay and the voltage end, and judging the relay state based on the difference, reducing the influence of the peripheral circuit, especially the equivalent capacitor, on the voltage difference between the two ends of the relay, so as to accurately judge whether the relay is abnormal.

[0042] The relay detection method disclosed in the embodiment of the present application can be used, but not limited to, in the detection process of relays in batteries used in electrical devices such as vehicles, ships or aircraft. The relay detection method disclosed in the present application can be used, which is conducive to accurately determining whether the relay is abnormal and improving the accuracy of the detection result.

[0043] The electric device in the embodiment of the present application may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0044] The present application embodiment provides a relay detection method 100. Figure 1 , the relay detection method 100 includes steps 110 to 130 .

[0045] Step 110 , when the relay is disconnected, control the voltage regulating circuit 10 to adjust the first voltage difference. The voltage regulating circuit 10 is configured to change the first voltage difference. The first voltage difference indicates a voltage difference between a first terminal of the relay and a first voltage terminal of the voltage regulating circuit 10 .

[0046] Step 120, determining a difference between the first voltage difference and the second voltage difference. The second voltage difference indicates a voltage difference between the second terminal of the relay and the first voltage terminal.

[0047] Step 130: Determine whether the relay is abnormal based on the difference between the first voltage difference and the second voltage difference.

[0048] In the embodiments of the present application, the term "battery" may include a battery cell, or a series, parallel or hybrid structure of multiple battery cells (eg, a battery pack or a battery module).

[0049] The relay is connected to the battery and can control the on and off of the power supply circuit. One end of the relay (i.e., the second end) can be connected to the positive or negative electrode of the battery to receive the first power supply voltage from the battery. The other end of the relay (i.e., the first end) can be connected to a load in the power supply circuit. The first voltage end and the second end of the relay are respectively connected to different electrodes of the battery and receive the second power supply voltage from the battery. During the use of the relay, abnormal conditions may occur, such as adhesion or short circuit failure.

[0050] In some embodiments, the voltage regulation circuit 10 is disposed in a battery management system (BMS). Figure 3 An example of a voltage regulating circuit 10 is shown in FIG. Figure 3 As shown, the second terminal A of the relay T1 is connected to the positive electrode of the battery, and the first voltage terminal C is connected to the negative electrode of the battery. In the prior art, it is usually determined whether the relay has abnormalities such as adhesion or short circuit based on the voltage difference between the voltage U1 at the first terminal B of the relay and the voltage U2 at the second terminal A (i.e., U1-U2). Figure 3 It can be seen that after the relay T1 is disconnected, the energy stored in the equivalent capacitors C1, C2 and C3 cannot be discharged quickly, so U1 cannot change quickly. For a period of time, the voltage difference U1-U2 between B and A will not change significantly, resulting in the relay being judged as being in an abnormal state such as adhesion or short circuit even though it has been disconnected.

[0051] Therefore, it is possible to determine whether the relay is abnormal by the difference between the first voltage difference and the second voltage difference. Figure 3In the example shown, the first voltage difference indicates the voltage difference between the first terminal B of the relay T1 and the first voltage terminal C (i.e., U1-U3), and the second voltage difference indicates the voltage difference between the second terminal A of the relay T1 and the first voltage terminal C (i.e., U2-U3). When the relay is disconnected, when the circuit topology of the voltage regulating circuit 10 changes, the first voltage difference U1-U3 will change, resulting in the difference between the first voltage difference and the second voltage difference (i.e., (U1-U3)-(U2-U3)) also changing, thereby reducing the influence of peripheral circuits such as equivalent capacitors C1, C2, and C3 on the detection results. The term "circuit topology" may also be referred to as "circuit structure", indicating the connection relationship and properties of the circuit, such as branches and nodes, subject to constraints such as Kirchhoff's voltage law and Kirchhoff's current law. The circuit topology describes the physical connection relationship between the various components in the circuit, and different circuit topologies can achieve different circuit design requirements and circuit functions. How to control the voltage regulating circuit to adjust the first voltage difference will be described in detail below.

[0052] It should be noted that although Figure 3 In the figure, it is shown as being connected to the positive and negative electrodes of the battery respectively, but in other embodiments, the second terminal A of the relay T1 and the first voltage terminal C can also be connected to a power supply device such as an external voltage source. For example, the first voltage terminal C can be connected to a reference ground or a reference power supply, so as to detect the difference between the first voltage difference and the second voltage difference. The first power supply voltage and the second power supply voltage can be designed according to the usage scenario, and can be but not limited to the positive and negative electrodes of the battery, an external power supply device, etc., and can be positive and negative pressure, positive pressure at the same time, negative pressure at the same time, etc., and the present disclosure does not limit this.

[0053] In some embodiments, the voltage regulating circuit 10 may use an existing insulation detection circuit in the BMS, or may use a separately designed circuit, as long as the function of changing the first voltage difference can be achieved. The present disclosure does not limit the design method of the voltage regulating circuit 10.

[0054] When the relay is disconnected, the voltage regulating circuit is used to adjust the difference between the first voltage difference and the second voltage difference between the two ends of the relay and the first voltage end, thereby reducing the influence of the peripheral circuit connected to the relay on the voltage at the two ends of the relay. By judging the difference between the first voltage difference and the second voltage difference, it is possible to accurately determine whether the relay is abnormal, thereby improving the accuracy of the detection result.

[0055] According to some embodiments of the present application, the voltage regulating circuit 10 further includes a reference terminal. Figure 2 , step 120 includes steps 210 to 260.

[0056] Step 210: Obtain a third voltage difference. The third voltage difference indicates a voltage difference between the first terminal and the reference terminal of the relay.

[0057] Step 220, obtaining a fourth voltage difference. The fourth voltage difference indicates a voltage difference between the reference terminal and the first voltage terminal.

[0058] Step 230: sum the third voltage difference and the fourth voltage difference to obtain the first voltage difference.

[0059] Step 240, obtaining a fifth voltage difference. The fifth voltage difference indicates a voltage difference between the second terminal and the reference terminal of the relay.

[0060] Step 250: sum the fifth voltage difference and the fourth voltage difference to obtain a second voltage difference.

[0061] Step 260: Obtain a difference between the first voltage difference and the second voltage difference according to the first voltage difference and the second voltage difference.

[0062] like Figure 3 As shown, the reference terminal D is a voltage reference node used when calculating the first voltage difference and the second voltage difference, and can be designed according to the use requirements, for example, it can be a power ground, or a reference voltage input from the outside, which is not limited in the present disclosure. Figure 3 In the example shown, the reference terminal D is the power ground GND of the voltage regulating circuit 10, that is, the power ground GND of the battery. The positive electrode of the battery provides a positive voltage (i.e., the first power voltage) to the second terminal A of the relay T1, and the negative electrode of the battery provides a negative voltage (i.e., the second power voltage) to the first voltage terminal C.

[0063] from Figure 3 It can be seen that U1-U3=(U1-U4)+(U4-U3), that is, the first voltage difference can be obtained by summing the third voltage difference (i.e., U1-U4) and the fourth voltage difference (i.e., U4-U3). U2-U3=(U2-U4)+(U4-U3), that is, the second voltage difference can be obtained by summing the fifth voltage difference (i.e., U2-U4) and the fourth voltage difference (i.e., U4-U3). In some embodiments, the second voltage difference U2-U3 can also be directly calculated based on the voltage difference between the first power supply voltage and the second power supply voltage (e.g., Figure 3 The voltage difference between the positive and negative electrodes of the battery is used to determine the voltage.

[0064] The voltage difference between the two ends of the relay and the reference end and the voltage difference between the first voltage end and the reference end are determined respectively. The first voltage difference can be changed by changing the voltage difference between the first voltage end and the reference end, thereby simplifying the detection process.

[0065] According to some embodiments of the present application, reference Figure 3The voltage regulating circuit 10 further includes a first resistor 14 and a first voltage regulating circuit 21 .

[0066] The first resistor 14 is configured to be connected in series between the reference terminal and the second terminal of the relay T1 .

[0067] The first voltage regulating circuit 21 is connected in parallel with the first resistor 14 , includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

[0068] The first resistor 14 may include at least one resistor. Figure 3 In the figure, it is shown as including two resistors. The first resistor 14 can also be designed according to the usage scenario. For example, the number of resistors can be increased or decreased, and different components such as switches can also be included. Figure 3 As shown in the figure, it includes a resistor and a switch. The first voltage regulating circuit 21 can also be designed according to the usage scenario. For example, it can have resistors with different numbers and / or resistance values. The present disclosure does not limit this.

[0069] In some embodiments, the first resistor 14 may be connected to the second terminal A of the relay T1 through a switch.

[0070] exist Figure 3 In the example shown, the voltage regulating circuit 10 may further include a first subcircuit 11, a second subcircuit 12, and a third subcircuit 13. The first subcircuit 11, the second subcircuit 12, and the third subcircuit 13 each include two resistors and a switch. In some embodiments, the resistors and switches in the first subcircuit 11, the second subcircuit 12, and the third subcircuit 13 may be set to be the same as each other. In an example, the switch S1, the switch S2, and the switch S3 may use the same model, the resistor R11, the resistor R21, and the resistor R31 may have the same resistance, for example, all of which are 30.6 megohms; the resistor R12, the resistor R22, and the resistor R32 may also have the same resistance, for example, all of which are 75 kiloohms. It should be understood that in other embodiments, the first sub-circuit 11, the second sub-circuit 12 and the third sub-circuit 13 may be designed according to the usage scenario. For example, a switch may not be provided, or they may have different circuit structures from each other, with resistors having different numbers and / or resistance values, or at least one of the first sub-circuit 11, the second sub-circuit 12 and the third sub-circuit 13 may not be provided. In some other embodiments, the first sub-circuit 11, the second sub-circuit 12 and the third sub-circuit 13 may not be provided in the voltage regulation circuit 10, and the present disclosure does not limit this.

[0071] By properly setting the voltage regulating circuit, the first voltage difference can be changed, thereby improving the accuracy of the detection result.

[0072] According to some embodiments of the present application, reference Figure 3 The voltage regulating circuit 10 also includes a second resistor 15 and a second voltage regulating circuit 22 .

[0073] The second resistor 15 is configured to be connected in series between the reference terminal and the first voltage terminal.

[0074] The second voltage regulating circuit 22 is connected in parallel with the second resistor 15 , includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

[0075] The second resistor 15 may include at least one resistor. Figure 3 In the figure, it is shown as including two resistors. The second resistor 15 can also be designed according to the usage scenario. For example, the number of resistors can be increased or decreased, and different components such as switches can be included. The circuit structure can be the same as or different from that of the first resistor 14. Figure 3 As shown in the figure, it includes a resistor and a switch. The second voltage regulating circuit 22 can also be designed according to the usage scenario. For example, it can have the same or different circuit structure as the first voltage regulating circuit 21, and have resistors with different numbers and / or resistance values. The present disclosure does not limit this.

[0076] In some embodiments, the second resistor 15 can be connected to the first voltage terminal C through a switch.

[0077] by Figure 3For example, when the switch S4 in the first voltage regulating circuit 21 is closed, the circuit topology changes. Since the resistor R1 in the first voltage regulating circuit 21 is connected, the resistor R1 is connected in parallel with the first resistor 14 at this time. Since the resistance value after parallel connection changes, the current I1 flowing through the second resistor 15 will also change accordingly. The voltage across the second resistor 15 is the fourth voltage difference U4-U3=(R51+R52)×I1. Since the current I1 changes, the fourth voltage difference will also change accordingly. According to the above, the first voltage difference U1-U3=(U1-U4)+(U4-U3). When the fourth voltage difference changes, the first voltage difference U1-U3 will also change accordingly. Similarly, when the switch S5 in the second voltage regulating circuit 22 is closed, since the resistor R2 in the second voltage regulating circuit 22 is connected, the resistor R2 is connected in parallel with the second resistor 15 at this time. Since the resistance value after parallel connection changes, the current I2 flowing through the first resistor 14 will also change accordingly. The voltage across the first resistor 14 is the third voltage difference U2-U4=(R41+R42)×I2. The second voltage difference U2-U3 is equal to the voltage difference between the positive and negative electrodes of the battery, and the fourth voltage difference U4-U3=(U2-U3)-(U2-U4)=(U2-U3)-(R41+R42)×I2. As the current I2 changes, the fourth voltage difference U4-U3 will also change, causing the first voltage difference U1-U3 to change.

[0078] By properly setting the voltage regulating circuit, the first voltage difference can be changed, thereby improving the accuracy of the detection result.

[0079] According to some embodiments of the present application, reference Figure 4 , step 110 includes at least one of step 410 and step 420.

[0080] Step 410 , controlling the first voltage regulating circuit 21 to change a state of at least one switch in the first voltage regulating circuit 21 .

[0081] Step 420 , controlling the second voltage regulating circuit 22 to change a state of at least one switch in the second voltage regulating circuit 22 .

[0082] As can be seen from the above, step 110 can be implemented by changing the switch state in the first voltage regulating circuit 21 and / or changing the switch state in the second voltage regulating circuit 22 .

[0083] It should be understood that Figure 3 This is just an example of the voltage regulating circuit 10. The switch control method in the first voltage regulating circuit 21 and the switch control method in the second voltage regulating circuit 22 can be designed according to different circuit structures, and the present disclosure does not limit this.

[0084] By controlling the switch state in the voltage regulating circuit, the first voltage difference can be changed accordingly, thereby reducing the complexity of the detection process.

[0085] According to some embodiments of the present application, the first voltage regulating circuit 21 includes a first voltage regulating resistor R1 and a first switch S4 connected in series. The second voltage regulating circuit 22 includes a second voltage regulating resistor R2 and a second switch S5 connected in series. Figure 5 , step 110 includes steps 510 to 530.

[0086] Step 510 , in response to the fifth voltage difference being greater than the fourth voltage difference, closing the first switch S4 and opening the second switch S5 .

[0087] Step 520 , in response to the fifth voltage difference being smaller than the fourth voltage difference, closing the second switch S5 and opening the first switch S4 .

[0088] Step 530 , in response to the fifth voltage difference being equal to the fourth voltage difference, closing any one of the first switch S4 and the second switch S5 .

[0089] As can be seen from the above, the first voltage difference can be changed by closing any one of the first switch S4 and the second switch S5 and opening the other switch. In order to make the change of the first voltage difference as large as possible, the states of the two switches can be determined according to the difference between the fifth voltage difference and the fourth voltage difference. In some embodiments, if there is a negative value in the fourth voltage difference and the fifth voltage difference, the absolute values ​​of the two can be compared.

[0090] The on and off of the first switch and the second switch are determined according to the values ​​of the fourth voltage difference and the fifth voltage difference, so that the change of the first voltage difference is as large as possible, making the detection result more accurate.

[0091] According to some embodiments of the present application, the relay detection method 100 further includes a process 600 before step 110. Figure 6 , process 600 includes steps 610 to 620.

[0092] Step 610, determining the ratio of the fifth voltage difference to the fourth voltage difference.

[0093] Step 620, determining whether the voltage regulating circuit 10 has a fault according to whether the ratio of the fifth voltage difference to the fourth voltage difference satisfies a predetermined voltage condition.

[0094] Continue with Figure 3For example, if there is a fault in the voltage regulation circuit 10, even if the circuit topology of the voltage regulation circuit 10 is changed, the first voltage difference may not change accordingly. For example, if the third sub-circuit 13 or the first resistor 14 is short-circuited, even if the switch S4 in the first voltage regulation circuit 21 is closed, since the first voltage regulating resistor R1 will not be incorporated into the circuit, the current flowing through the second resistor 15 will not change. At this time, the fourth voltage difference will not change, resulting in no change in the first voltage difference, and it is impossible to accurately determine whether the relay T1 is abnormal.

[0095] Therefore, before detecting the relay T1, it is possible to determine whether the voltage regulating circuit 10 has a fault. If the voltage regulating circuit 10 has a fault, the circuit fault is reported, and the relay detection result is determined to be invalid, thereby reducing the risk of false alarms.

[0096] The predetermined voltage condition can be designed according to different usage scenarios. Figure 3 As shown, it can be determined whether the voltage regulating circuit 10 is faulty based on the ratio of the fifth voltage difference to the fourth voltage difference (U2-U4) / (U4-U3) and the predetermined voltage condition. If a resistor is short-circuited or otherwise abnormal, the corresponding voltage difference will also be abnormal. For example, if (U2-U4) / (U4-U3) is small and less than the predetermined voltage condition, it can be considered that the third sub-circuit 13 or the first resistor 14 is short-circuited; if (U2-U4) / (U4-U3) is large and greater than the predetermined voltage condition, it can be considered that the second sub-circuit 12 or the second resistor 15 is short-circuited. In some embodiments, if there is a negative value in the fourth voltage difference and the fifth voltage difference, it can be determined whether the voltage regulating circuit 10 is faulty based on whether the ratio of their absolute values ​​meets the predetermined voltage condition.

[0097] Before determining whether the relay is abnormal, first determine whether the voltage regulation circuit is faulty to eliminate the risk of detection abnormality caused by a voltage regulation circuit fault.

[0098] According to some embodiments of the present application, the predetermined voltage condition includes any one of the following:

[0099] The ratio of the fifth voltage difference to the fourth voltage difference is greater than the ratio of the first threshold resistance to the resistance of the second resistance 15, and is less than the ratio of the resistance of the first resistance 14 to the second threshold resistance; or the ratio of the fifth voltage difference to the fourth voltage difference is greater than the ratio of the third threshold resistance to the resistance of the first resistance 14, and is less than the ratio of the resistance of the second resistance 15 to the fourth threshold resistance.

[0100] The resistance values ​​of the first threshold resistor, the second threshold resistor, the third threshold resistor, and the fourth threshold resistor can be designed according to the usage scenario, for example, they can be determined in combination with the actual circuit and circuit simulation results. Figure 3In the example shown, when (U2-U4) / (U4-U3) is less than the first threshold resistance / (R51+R52) or less than the third threshold resistance / (R41+R42), it can be considered that the third sub-circuit 13 or the first resistor 14 is short-circuited; when (U2-U4) / (U4-U3) is greater than (R41+R42) / the second threshold resistance or greater than (R51+R52) / the fourth threshold resistance, it can be considered that the second sub-circuit 12 or the second resistor 15 is short-circuited.

[0101] By determining whether the ratio of the fifth voltage difference to the fourth voltage difference falls within a predetermined range, it can be determined whether there is a fault such as a short circuit in the voltage regulation circuit.

[0102] Based on the same technical concept, the embodiment of the present application provides a relay detection device. The embodiment of the relay detection device can refer to the embodiment of the relay detection method, and the repeated parts will not be repeated. Figure 7 The relay detection device 700 includes a first module 710 , a second module 720 and a third module 730 .

[0103] The first module 710 is used to control the voltage regulating circuit 10 to adjust the first voltage difference when the relay is disconnected. The voltage regulating circuit 10 is configured to change the first voltage difference. The first voltage difference indicates the voltage difference between the first end of the relay and the first voltage end of the voltage regulating circuit 10.

[0104] The second module 720 is used to determine the difference between the first voltage difference and the second voltage difference. The second voltage difference indicates the voltage difference between the second terminal of the relay and the first voltage terminal.

[0105] The third module 730 is used to determine whether the relay is abnormal according to the difference between the first voltage difference and the second voltage difference.

[0106] The first module 710, the second module 720 and the third module 730 in the relay detection device 700 may correspond to the following Figure 1 For the sake of brevity, steps 110 to 130 in the relay detection method 100 are not described here in detail. It should be understood that, corresponding to the embodiment of the relay detection method 100, the embodiment of the relay detection device 700 may also include more modules.

[0107] It should be noted that the functions of the various modules discussed herein can be divided into multiple modules, and / or at least some functions of multiple modules can be combined into a single module. The specific module discussed herein performing an action includes the specific module itself performing the action, or alternatively the specific module calling or otherwise accessing another component or module that performs the action (or performs the action in conjunction with the specific module). Therefore, the specific module that performs an action can include the specific module itself that performs the action and / or another module that the specific module calls or otherwise accesses and performs the action.

[0108] It should also be understood that various techniques may be described herein in the general context of software hardware elements or program modules. Figure 7 The various modules described can be implemented in hardware or in hardware in combination with software and / or firmware. For example, these modules can be implemented as computer program code / instructions, which are configured to be executed in one or more processors and stored in a computer-readable storage medium. Alternatively, these modules can be implemented as hardware logic / circuits. The hardware logic / circuit may include an integrated circuit chip (which includes a processor (e.g., a central processing unit (CPU), a microcontroller, a microprocessor, a digital signal processor (DSP), etc.), a memory, one or more communication interfaces, and / or one or more components in other circuits), and may optionally execute the received program code and / or include embedded firmware to perform functions.

[0109] Based on the same technical concept, an embodiment of the present application provides a battery management system. The battery management system includes a voltage regulating circuit 10, at least one processor, and at least one memory communicatively connected to the at least one processor.

[0110] The voltage regulating circuit 10 is configured to change a first voltage difference. The first voltage difference indicates a voltage difference between a first terminal of the relay and a first voltage terminal of the voltage regulating circuit.

[0111] At least one memory stores instructions. When the instructions are executed by at least one processor individually or collectively, the battery management system executes the relay detection method 100 in the above embodiment.

[0112] The technology described herein may be supported by a battery management system. For example, the relay detection device 700 may be fully or at least partially implemented by a battery management system or a similar device or system.

[0113] As described above, the voltage regulating circuit 10 may use the existing insulation detection circuit in the BMS, or may use a separately designed circuit, as long as it can achieve the function of changing the first voltage difference. The present disclosure does not limit the design method of the voltage regulating circuit 10.

[0114] According to some embodiments of the present application, the voltage regulating circuit 10 further includes a reference terminal, a first resistor 14 and a first voltage regulating circuit 21 .

[0115] The first resistor 14 is configured to be connected in series between the reference terminal and the second terminal of the relay T1 .

[0116] The first voltage regulating circuit 21 is connected in parallel with the first resistor 14 , includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

[0117] The designs of the first resistor 14 and the first voltage regulating circuit 21 have been described in detail above, and will not be repeated here for the sake of brevity.

[0118] By properly setting the voltage regulating circuit, the first voltage difference can be changed, thereby improving the accuracy of the detection result.

[0119] According to some embodiments of the present application, the voltage regulating circuit 10 further includes a second resistor 15 and a second voltage regulating circuit 22 .

[0120] The second resistor 15 is configured to be connected in series between the reference terminal and the first voltage terminal.

[0121] The second voltage regulating circuit 22 is connected in parallel with the second resistor 15 , includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

[0122] The designs of the second resistor 15 and the second voltage regulating circuit 22 have been described in detail above, and for the sake of brevity, they will not be repeated here.

[0123] By properly setting the voltage regulating circuit, the first voltage difference can be changed, thereby improving the accuracy of the detection result.

[0124] An embodiment of the present application also provides a computer-readable storage medium on which instructions are stored. When the instructions are executed individually or collectively by one or more processors of the battery management system, the battery management system executes the relay detection method in any of the above embodiments.

[0125] Computer-readable storage media include volatile and nonvolatile, removable and non-removable media implemented by any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD), or other optical storage devices, magnetic cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, or any other non-transmission media that can be used to store information for access by a computer device.

[0126] An embodiment of the present application also provides a computer program product, including instructions, which, when executed individually or collectively by one or more processors of the battery management system, enable the battery management system to execute the relay detection method in any of the above embodiments.

[0127] A specific embodiment of the present application is described below. It should be understood that this specific embodiment is described for illustrative purposes only and should not be interpreted as limiting the present application.

[0128] In the battery management system, a voltage regulating circuit 10 is provided. Figure 3 As shown, the voltage regulating circuit 10 includes a first subcircuit 11, a second subcircuit 12, a third subcircuit 13, a first resistor 14, a second resistor 15, a first voltage regulating circuit 21, and a second voltage regulating circuit 22. The positive electrode of the battery is connected to the second terminal A of the relay T1, and the negative electrode is connected to the first voltage terminal C.

[0129] Before testing the relay T1, it is determined whether the ratio of the fifth voltage difference to the fourth voltage difference (U2-U4) / (U4-U3) satisfies a predetermined voltage condition. If so, it is considered that the voltage regulating circuit 10 has no faults and testing can begin.

[0130] When the relay T1 is disconnected, if the fifth voltage difference is greater than the fourth voltage difference, the first switch S4 in the first voltage regulating circuit 21 is closed, and the second switch S5 in the second voltage regulating circuit 22 is in an open state; if the fifth voltage difference is less than the fourth voltage difference, the second switch S5 is closed, and the first switch S4 is in an open state; if the fifth voltage difference is equal to the fourth voltage difference, either the first switch S4 or the second switch S5 is closed, and the other is in an open state. At this time, the circuit topology changes, the fourth voltage difference (U4-U3) changes, and the first voltage difference U1-U3=(U1-U4)+(U4-U3) also changes accordingly.

[0131] Whether the relay T1 is abnormal is determined based on the difference between the first voltage difference U1 - U3 and the second voltage difference U2 - U3 (U1 - U3) - (U2 - U3) = [(U1 - U4) + (U4 - U3)] - [(U2 - U4) + (U4 - U3)].

[0132] Figure 8 A voltage regulating circuit 10 is shown which is capable of simultaneously testing two relays T1 and T2. Figure 8 The voltage regulating circuit 10 in the embodiment adds a fourth subcircuit 16. The fourth subcircuit 16 includes a resistor R61, a resistor R62 and a switch S6. The detection method for relay T1 is the same as described above. The detection method for relay T2 is similar to the detection method for relay T1, and the second subcircuit 12, the third subcircuit 13, the first resistor 14, the second resistor 15, the fourth subcircuit 16 (equivalent to the first subcircuit 11 when detecting relay T1) and the first voltage regulating circuit 21, the second voltage regulating circuit 22 can be used to determine the voltage difference U5-U2 (equivalent to the first voltage difference) between the first terminal E of relay T2 and the second terminal A of relay T1 (equivalent to the first voltage terminal C described above) and the voltage difference U3-U2 (equivalent to the second voltage difference) between the second terminal of relay T2 (i.e., point C in the figure) and the second terminal A of relay T1. Voltage difference U4-U2=(U5-U4)+(U4-U2), voltage difference U3-U2=(U3-U4)+(U4-U2).

[0133] According to the above analysis, when the first switch S4 or the second switch S5 is closed, U4-U2 will change, causing the voltage difference U5-U2 to change accordingly. Therefore, according to the difference between the voltage difference U5-U2 and the voltage difference U3-U2, it can be determined whether the relay T2 is abnormal. Figure 8 The example in the embodiment can detect two relays T1 and T2 at the same time, shortening the total detection time. It should be understood that if there are more relays, the voltage regulating circuit 10 can be modified accordingly according to the detection method in the above embodiment.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A relay detection method, characterized in that: include: controlling a voltage regulating circuit to regulate a first voltage difference when the relay is disconnected, wherein the voltage regulating circuit is configured to change the first voltage difference, the first voltage difference indicating a voltage difference between a first end of the relay and a first voltage end of the voltage regulating circuit; determining a difference between the first voltage difference and a second voltage difference, wherein the second voltage difference indicates a voltage difference between a second terminal of the relay and the first voltage terminal; and Whether the relay is abnormal is determined according to a difference between the first voltage difference and the second voltage difference.

2. The relay detection method according to claim 1, characterized in that: The voltage regulating circuit further includes a reference terminal, and determining the difference between the first voltage difference and the second voltage difference includes: acquiring a third voltage difference, the third voltage difference indicating a voltage difference between the first end of the relay and the reference end; acquiring a fourth voltage difference, the fourth voltage difference indicating a voltage difference between the reference terminal and the first voltage terminal; summing the third voltage difference and the fourth voltage difference to obtain the first voltage difference; acquiring a fifth voltage difference, the fifth voltage difference indicating a voltage difference between the second end of the relay and the reference end; summing the fifth voltage difference and the fourth voltage difference to obtain the second voltage difference; and A difference between the first voltage difference and the second voltage difference is obtained according to the first voltage difference and the second voltage difference.

3. The relay detection method according to claim 2, characterized in that: The voltage regulating circuit further includes: a first resistor configured to be connected in series between the reference terminal and the second terminal of the relay; and The first voltage regulating circuit is connected in parallel with the first resistor, includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

4. The relay detection method according to claim 3, characterized in that: The voltage regulating circuit further includes: a second resistor configured to be connected in series between the reference terminal and the first voltage terminal; and The second voltage regulating circuit is connected in parallel with the second resistor, includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

5. The relay detection method according to claim 4, characterized in that: The controlling the voltage regulating circuit to adjust the first voltage difference when the relay is disconnected comprises at least one of the following: controlling the first voltage regulating circuit to change a state of at least one switch in the first voltage regulating circuit; Controlling the second voltage regulating circuit changes a state of at least one switch in the second voltage regulating circuit.

6. The relay detection method according to claim 4 or 5, characterized in that: The first voltage regulating circuit includes a first voltage regulating resistor and a first switch connected in series, the second voltage regulating circuit includes a second voltage regulating resistor and a second switch connected in series, and controlling the voltage regulating circuit to adjust the first voltage difference when the relay is disconnected includes: In response to the fifth voltage difference being greater than the fourth voltage difference, closing the first switch and opening the second switch; In response to the fifth voltage difference being less than the fourth voltage difference, closing the second switch and opening the first switch; and In response to the fifth voltage difference being equal to the fourth voltage difference, either one of the first switch and the second switch is closed.

7. The relay detection method according to claim 4 or 5, characterized in that: Also includes: Before controlling the voltage regulating circuit to adjust the first voltage difference when the relay is disconnected, determining a ratio of the fifth voltage difference to the fourth voltage difference; as well as Whether the voltage regulating circuit has a fault is determined according to whether a ratio of the fifth voltage difference to the fourth voltage difference satisfies a predetermined voltage condition.

8. The relay detection method according to claim 7, characterized in that: The predetermined voltage condition includes any one of the following: The ratio of the fifth voltage difference to the fourth voltage difference is greater than the ratio of the first threshold resistance to the resistance of the second resistance, and is less than the ratio of the resistance of the first resistance to the second threshold resistance; or A ratio of the fifth voltage difference to the fourth voltage difference is greater than a ratio of a third threshold resistor to a resistance value of the first resistor, and is less than a ratio of a resistance value of the second resistor to a fourth threshold resistor.

9. A relay detection device, characterized in that: include: A first module, configured to control a voltage regulating circuit to regulate a first voltage difference when the relay is disconnected, wherein the voltage regulating circuit is configured to change the first voltage difference, the first voltage difference indicating a voltage difference between a first end of the relay and a first voltage end of the voltage regulating circuit; a second module for determining a difference between the first voltage difference and a second voltage difference, wherein the second voltage difference indicates a voltage difference between a second terminal of the relay and the first voltage terminal; and The third module is used to determine whether the relay is abnormal according to the difference between the first voltage difference and the second voltage difference.

10. A battery management system, characterized in that: include: a voltage regulating circuit configured to cause a first voltage difference to vary, the first voltage difference being indicative of a voltage difference between a first end of the relay and a first voltage end of the voltage regulating circuit; at least one processor; as well as At least one memory is communicatively connected to the at least one processor, and the at least one memory stores instructions, and when the instructions are executed by the at least one processor individually or collectively, the battery management system executes the relay detection method according to any one of claims 1 to 8.

11. The battery management system according to claim 10, characterized in that: The voltage regulating circuit further includes: Reference terminal; a first resistor configured to be connected in series between the reference terminal and the second terminal of the relay; and The first voltage regulating circuit is connected in parallel with the first resistor, includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

12. The battery management system according to claim 11, characterized in that: The voltage regulating circuit further includes: a second resistor configured to be connected in series between the reference terminal and the first voltage terminal; and The second voltage regulating circuit is connected in parallel with the second resistor, includes at least one switch, and is configured to change the first voltage difference by changing a state of the at least one switch.

13. A computer-readable storage medium, characterized in that: Instructions are stored, and when the instructions are executed individually or collectively by the at least one processor of the battery management system according to any one of claims 10 to 12, the battery management system executes the relay detection method according to any one of claims 1 to 8.

14. A computer program product, characterized in that The method comprises instructions, which, when executed individually or collectively by the at least one processor of the battery management system according to any one of claims 10 to 12, cause the battery management system to perform the relay detection method according to any one of claims 1 to 8.

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