Battery management system and battery equipment

Abstract

The utility model relates to a battery management system and battery equipment, if an over-limit alarm circuit detects that the temperature of a to-be-monitored battery cell exceeds the limit based on the temperature of the battery cell, a first signal is output to indicate that the temperature of the to-be-monitored battery cell exceeds the limit; and if the fault alarm circuit detects that the temperature monitoring circuit breaks down based on the cell temperature, a second signal is output to indicate that the temperature monitoring circuit breaks down. According to the scheme, the temperature monitoring circuit can be monitored through the fault alarm circuit while the temperature of the to-be-monitored battery cell is monitored through the temperature monitoring circuit, so that identification can be carried out when the temperature of the to-be-monitored battery cell exceeds the limit, and indication can be carried out when the temperature monitoring circuit breaks down. Therefore, the fault of the temperature monitoring circuit can be found in time, the condition of temperature over-limit false alarm caused by the fault of the temperature monitoring circuit is relieved, and the temperature monitoring accuracy of the battery cell is improved.

Description

Technical Field

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

[0002] With the development of new energy technology, secondary batteries represented by lithium batteries are gradually applied to energy storage power systems, electric vehicles, military equipment, aerospace and other fields, bringing great convenience to people's daily production and life. In these products, battery cell safety is a crucial core link. Any battery cell failure may lead to serious consequences, such as increased fire risk. Therefore, there are extremely high requirements for battery cell temperature monitoring.

[0003] However, in the related art, when monitoring the temperature of a battery cell, a temperature over-limit false alarm often occurs due to a fault in the temperature monitoring circuit. Utility Model Content

[0004] Based on this, it is necessary to propose a battery management system and a battery device to alleviate the situation where the temperature monitoring circuit fails and the temperature exceeds the limit and the false alarm occurs, and to improve the temperature monitoring accuracy of the battery cell.

[0005] The present application provides a battery management system, including: a temperature monitoring circuit, an over-limit alarm circuit and a fault alarm circuit, wherein the temperature monitoring circuit is arranged in a battery cell to be monitored, and the temperature monitoring circuit is used to monitor the battery cell temperature of the battery cell to be monitored; the over-limit alarm circuit is connected to the temperature monitoring circuit, and is used to output a first signal when it is detected based on the battery cell temperature that the temperature of the battery cell to be monitored exceeds the limit, and the first signal indicates that the temperature of the battery cell to be monitored exceeds the limit; the fault alarm circuit is connected to the temperature monitoring circuit, and is used to output a second signal when it is detected based on the battery cell temperature that the temperature monitoring circuit fails, and the second signal indicates that the temperature monitoring circuit fails.

[0006] In the above scheme, the temperature of the battery cell to be monitored can be monitored by the temperature monitoring circuit, and output to the over-limit alarm circuit and the fault alarm circuit for comparison. If the over-limit alarm circuit detects that the temperature of the battery cell to be monitored exceeds the limit based on the battery cell temperature, it outputs a first signal to indicate that the temperature of the battery cell to be monitored exceeds the limit; if the fault alarm circuit detects that the temperature monitoring circuit fails based on the battery cell temperature, it outputs a second signal to indicate that the temperature monitoring circuit fails. In this scheme, the temperature of the battery cell to be monitored can be monitored by the temperature monitoring circuit while the temperature monitoring circuit can be monitored by the fault alarm circuit. It can identify when the temperature of the battery cell to be monitored exceeds the limit, and indicate when the temperature monitoring circuit fails. In this way, it can be discovered in time when the temperature monitoring circuit fails, which alleviates the situation of false alarm of temperature exceeding the limit caused by the failure of the temperature monitoring circuit, and improves the accuracy of temperature monitoring of the battery cell.

[0007] In some embodiments, the over-limit alarm circuit outputs the first signal when the battery cell temperature is greater than a preset high temperature threshold and less than a preset extreme high temperature, or when the battery cell temperature is greater than a preset extreme low temperature and less than a preset low temperature threshold; wherein the preset high temperature threshold is greater than the preset low temperature threshold, and the preset extreme high temperature is greater than the preset extreme low temperature; when the battery cell temperature is greater than the preset extreme high temperature or less than the preset extreme low temperature, the over-limit alarm circuit outputs the first signal and the fault alarm circuit outputs the second signal to indicate that a fault has occurred in the temperature monitoring circuit.

[0008] In the above scheme, when the cell temperature output by the temperature monitoring circuit is greater than the preset high temperature threshold and less than the preset high temperature limit, or greater than the preset low temperature limit and less than the preset low temperature threshold, only the over-limit alarm circuit outputs the first signal; and when the cell temperature output by the temperature monitoring circuit is greater than the preset high temperature limit or less than the preset low temperature limit, not only the over-limit alarm circuit outputs the first signal, but the fault alarm circuit also outputs the second signal. In this way, the judgment of whether the temperature monitoring circuit is faulty is realized according to whether the first signal is output alone or the first signal and the second signal are output simultaneously, which has a high accuracy of temperature monitoring circuit fault detection.

[0009] In some embodiments, the second signal includes an open circuit fault signal, the fault alarm circuit includes an open circuit comparison circuit and a first reference signal circuit, the first input end of the open circuit comparison circuit is connected to the temperature monitoring circuit, and the second input end of the open circuit comparison circuit is connected to the first output end of the first reference signal circuit; wherein, the first reference signal circuit outputs a first reference signal representing the preset extreme low temperature through the first output end, and the open circuit comparison circuit is used to output an open circuit fault signal when the battery cell temperature is lower than the preset extreme low temperature, and the open circuit fault signal is used to indicate that an open circuit fault occurs in the temperature monitoring circuit.

[0010] In the above scheme, the fault alarm circuit is configured with an open circuit comparison circuit and a first reference signal circuit, and determines whether the temperature monitoring circuit has an open circuit fault by comparison with the comparison circuit, which has high open circuit fault detection accuracy.

[0011] In some embodiments, the second signal includes a short-circuit fault signal, and the fault alarm circuit also includes a short-circuit comparison circuit, a first input end of the short-circuit comparison circuit is connected to the temperature monitoring circuit, and a second input end of the short-circuit comparison circuit is connected to the second output end of the first reference signal circuit; wherein, the first reference signal circuit outputs a second reference signal representing the preset extreme high temperature through the second output end, and the short-circuit comparison circuit is used to output a short-circuit fault signal when the battery cell temperature is greater than the preset extreme high temperature, and the short-circuit fault signal is used to indicate that a short-circuit fault occurs in the temperature monitoring circuit.

[0012] In the above scheme, the fault alarm circuit is also configured with a short-circuit comparison circuit, which determines whether there is a short-circuit fault in the temperature monitoring circuit by comparing the comparison circuit, and has high short-circuit fault detection accuracy.

[0013] In some embodiments, the temperature monitoring circuit uses a voltage signal to characterize the battery cell temperature; the first reference signal circuit includes a voltage source, a first resistor, a second resistor and a third resistor, the voltage source is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor, and the common end formed by the first resistor and the second resistor serves as the first output end of the first reference signal circuit, the second end of the second resistor is connected to the first end of the third resistor, and the common end formed by the second resistor and the third resistor serves as the second output end of the first reference signal circuit, and the second end of the third resistor is grounded.

[0014] The above scheme, in the form of a voltage divider circuit, provides voltages corresponding to the preset extreme low temperature and the preset extreme high temperature for the open circuit comparison circuit and the short circuit comparison circuit at the same time, and realizes fault detection of the temperature monitoring circuit in the form of a voltage signal. While improving the detection accuracy, it can also effectively reduce the circuit volume and save circuit costs.

[0015] In some embodiments, the battery management system also includes a fault alarm, and the output end of the open circuit comparison circuit and the output end of the short circuit comparison circuit are respectively connected to the fault alarm; the fault alarm is used to perform an alarm operation when receiving the open circuit fault signal or the short circuit fault signal.

[0016] In the above solution, the battery management system is also configured with a fault alarm, which implements a fault alarm of the temperature monitoring circuit in the form of an alarm, which is helpful for the user to know the actual operating status of the temperature monitoring circuit in time.

[0017] In some embodiments, the number of the battery cells to be monitored is multiple, and the number of the fault alarm is one; each battery cell to be monitored is respectively provided with an open circuit comparison circuit, a short circuit comparison circuit and a first reference signal circuit, and each open circuit comparison circuit and each short circuit comparison circuit are respectively connected to the fault alarm.

[0018] In the above scheme, when there are multiple cells to be monitored, each cell to be monitored is respectively configured with a temperature monitoring circuit and a fault alarm circuit, and shares a fault alarm, which can effectively reduce the cost of the alarm and the volume of the circuit.

[0019] In some embodiments, the number of the battery cells to be monitored is multiple, and the number of the fault alarms is consistent with the number of the battery cells to be monitored; each of the battery cells to be monitored is respectively provided with an open circuit comparison circuit, a short circuit comparison circuit and a first reference signal circuit, and the open circuit comparison circuit and the short circuit comparison circuit of each of the battery cells to be monitored are connected to one of the fault alarms.

[0020] In the above scheme, when there are multiple cells to be monitored, each cell to be monitored is respectively configured with a temperature monitoring circuit and a fault alarm circuit, and a fault alarm is respectively set. In this way, when a fault alarm occurs, the fault location can be known in time, thereby improving the accuracy of temperature monitoring.

[0021] In some embodiments, the fault alarm includes an open circuit alarm and a short circuit alarm; the output end of the open circuit comparison circuit is connected to the open circuit alarm, and the output end of the short circuit comparison circuit is connected to the short circuit alarm. The open circuit alarm is used to perform an alarm operation when receiving the open circuit fault signal, and the short circuit alarm is used to perform an alarm operation when receiving the short circuit fault signal.

[0022] In the above scheme, the open circuit fault and the short circuit fault are respectively implemented by different alarms, so that the fault type of the temperature monitoring circuit can be accurately known.

[0023] In some embodiments, the number of the battery cells to be monitored is multiple, and the number of the open circuit alarm and the short circuit alarm are both one; each battery cell to be monitored is respectively provided with one open circuit comparison circuit, one short circuit comparison circuit and one first reference signal circuit, each open circuit comparison circuit is respectively connected to the open circuit alarm, and each short circuit comparison circuit is respectively connected to the short circuit alarm.

[0024] In the above scheme, when there are multiple cells to be monitored, an alarm can be set for short-circuit fault alarm and open-circuit fault alarm respectively, which can improve the accuracy of fault type detection while reducing circuit volume and saving circuit cost.

[0025] In some embodiments, the number of the battery cells to be monitored is multiple, and the number of the open circuit alarms and the short circuit alarms are consistent with the number of the battery cells to be monitored; each battery cell to be monitored is respectively provided with an open circuit comparison circuit, a short circuit comparison circuit and a first reference signal circuit, each open circuit comparison circuit is connected to an open circuit alarm, and each short circuit comparison circuit is connected to a short circuit alarm.

[0026] In the above scheme, when there are multiple battery cells to be monitored, an alarm can be set for the short-circuit fault alarm and open-circuit fault alarm of each battery cell to be monitored. While improving the accuracy of fault type detection, the alarm position can also be accurately located, further improving the alarm reliability.

[0027] In some embodiments, the temperature monitoring circuit includes a pull-up power supply, a pull-up resistor and a thermistor, the first end of the pull-up resistor is connected to the pull-up power supply, the second end of the pull-up resistor is connected to the first end of the thermistor, the second end of the thermistor is grounded, and the fault alarm circuit is connected to the first end of the thermistor.

[0028] The above scheme adopts the voltage division method of thermistor and pull-up resistor to convert the cell temperature of the monitored cell into a voltage parameter, thereby realizing temperature monitoring, which has high temperature collection accuracy and convenience.

[0029] In some embodiments, the temperature monitoring circuit further includes an RC filter circuit, and the fault alarm circuit is connected to the first end of the thermistor through the RC filter circuit.

[0030] In the above scheme, after the voltage is collected by the voltage-dividing sampling circuit composed of the thermistor and the pull-up resistor, it is also necessary to filter it through the RC filter circuit and then output it to the over-limit alarm circuit and the fault alarm circuit to further improve the accuracy of temperature collection.

[0031] The present application also provides a battery device, comprising at least one battery cell and the above-mentioned battery management system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0033] Figure 1 This is a schematic diagram of the temperature monitoring circuit structure in some embodiments of the present application;

[0034] Figure 2 This is a schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application;

[0035] Figure 3 This is a schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application;

[0036] Figure 4 This is a schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application;

[0037] Figure 5 This is a schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application;

[0038] Figure 6 This is a schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application;

[0039] Figure 7 This is a schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application;

[0040] Figure 8 This is a schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application;

[0041] Fig. 9 Schematic diagram of the temperature monitoring circuit structure in some other embodiments of the present application.

[0042] Description of reference numerals:

[0043] 10-temperature monitoring circuit, 20-over-limit alarm circuit, 30-fault alarm circuit, 31-first reference signal circuit, 32-open circuit comparison circuit, 33-short circuit comparison circuit, U1-first comparator, RA-first pull-up resistor, U2-second comparator, RB-second pull-up resistor, 21-second reference signal circuit, 22-low temperature comparison circuit, 23-high temperature comparison circuit, U3-third comparator, RC-third pull-up resistor, U4-fourth comparator, RD-fourth pull-up resistor, R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-fifth resistor, R6-sixth resistor, 40-fault alarm, 50-over-limit alarm, 42-open circuit alarm, 41-short circuit alarm, 52-low temperature alarm, 51-high temperature alarm, R-pull-up resistor, RS-thermistor, 11-RC filter circuit. DETAILED DESCRIPTION

[0044] The following embodiments of the technical solution of the present application are 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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).

[0050] 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.

[0051] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. They 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 battery application fields, the market demand is also constantly expanding.

[0052] Batteries generally include multiple cells connected in series and / or in parallel. As the smallest energy storage unit in the battery, cell safety is a crucial core link. Any cell failure may lead to serious consequences. Temperature monitoring of the cell is an important means to prevent cell failure. At present, the battery management system (BMS) generally configures the temperature alarm function based on the temperature sampling of the cell. When the cell temperature is detected to be too high or too low, an alarm prompt message is output to alarm. However, when the temperature alarm is triggered, it often happens that the actual temperature of the cell is still within the safe operating temperature range, that is, it does not exceed the set high and low temperature limits.

[0053] After in-depth research, it was found that the battery cell temperature did not exceed the high and low temperature limits, but the temperature alarm was triggered, which was generally caused by a failure in the temperature monitoring circuit or device. Specifically, it may be caused by a short circuit or open circuit failure in the temperature monitoring circuit or device. In the new energy application scenario, the over-limit alarm caused by thermal runaway of the battery cell is a relatively high-level safety accident, while a short circuit or open circuit in the temperature monitoring circuit or device is a lower-level failure. If the two are not distinguished, it is easy for the system to fail to make the correct response measures.

[0054] To alleviate the above phenomenon, it is possible to consider detecting the failure of the temperature monitoring circuit or device, and output different alarm signals when the temperature monitoring circuit or device fails, so as to distinguish between the battery cell over-limit alarm and the temperature monitoring circuit or device failure.

[0055] Based on the above considerations, a temperature monitoring circuit, an over-limit alarm circuit, and a fault alarm circuit can be configured for the battery cell. The temperature of the battery cell to be monitored can be monitored by the temperature monitoring circuit, and output to the over-limit alarm circuit and the fault alarm circuit for comparison. If the over-limit alarm circuit detects that the temperature of the battery cell to be monitored exceeds the limit based on the battery cell temperature, it outputs a first signal to indicate that the temperature of the battery cell to be monitored exceeds the limit; if the fault alarm circuit detects that the temperature monitoring circuit fails based on the battery cell temperature, it outputs a second signal to indicate that the temperature monitoring circuit fails.

[0056] The above scheme can monitor the temperature of the battery cell to be monitored through the temperature monitoring circuit and monitor the temperature monitoring circuit through the fault alarm circuit at the same time. It can not only identify when the temperature of the battery cell to be monitored exceeds the limit, but also indicate when the temperature monitoring circuit fails. In this way, when the temperature monitoring circuit fails, it can be discovered in time, which alleviates the situation of false alarm of temperature exceeding the limit caused by the temperature monitoring circuit failure, and improves the accuracy of temperature monitoring of the battery cell.

[0057] The battery management system provided in the embodiment of the present application is applied to a battery device, and the battery device includes at least one battery cell. When there are multiple battery cells, the multiple battery cells can be connected in series and / or in parallel. The battery device can be a power battery that provides power for electric vehicles, etc., or an energy storage battery used in energy storage systems and other scenarios, without specific limitation.

[0058] See also Figure 1The present application provides a battery management system, including: a temperature monitoring circuit 10, an over-limit alarm circuit 20 and a fault alarm circuit 30. The temperature monitoring circuit 10 is arranged in a battery cell to be monitored, and the temperature monitoring circuit 10 is used to monitor the battery cell temperature of the battery cell to be monitored; the over-limit alarm circuit 20 is connected to the temperature monitoring circuit 10, and the over-limit alarm circuit 20 is used to output a first signal when it is detected based on the battery cell temperature that the temperature of the battery cell to be monitored exceeds the limit, and the first signal indicates that the temperature of the battery cell to be monitored exceeds the limit; the fault alarm circuit 30 is connected to the temperature monitoring circuit 10, and the fault alarm circuit 30 is used to output a second signal when it is detected based on the battery cell temperature that the temperature monitoring circuit 10 fails, and the second signal indicates that the temperature monitoring circuit 10 fails.

[0059] Specifically, the battery cell to be monitored is the battery cell that needs to be temperature monitored, which can be any battery cell in the battery device, or part or all of the battery cells in the battery device, without specific limitation. The temperature monitoring circuit 10 is a circuit used to collect the battery cell temperature of the battery cell to be monitored and output it. The over-limit alarm circuit 20 is a circuit used to determine whether the battery cell temperature output by the temperature monitoring circuit 10 exceeds the set threshold value (which may include a high temperature threshold value and / or a low temperature threshold value), and outputs a first signal when it exceeds the set threshold value. The fault alarm circuit 30 is a circuit used to determine whether the battery cell temperature output by the temperature monitoring circuit 10 exceeds the set limit value (which may include a high temperature limit and / or a low temperature limit), and outputs a second signal when it exceeds the set limit value.

[0060] In the process of monitoring the battery cell to be monitored, the temperature monitoring circuit 10 can transmit the battery cell temperature to the over-limit alarm circuit 20 and the fault alarm circuit 30 for analysis at the same time according to the actual monitoring results. It can be understood that the battery cell temperature output by the temperature monitoring circuit 10 can be represented by other parameters, such as voltage parameters, current parameters, etc., or a specific temperature value, which is not specifically limited. That is, the temperature monitoring circuit 10 can output a specific temperature value to the over-limit alarm circuit 20 and the fault alarm circuit 30 according to the monitoring results, or it can output a parameter representing the temperature value.

[0061] It should be noted that the over-limit alarm circuit 20 and the fault alarm circuit 30 can perform fault analysis based on the battery cell temperature respectively. In some embodiments, when it is detected that the temperature of the battery cell to be monitored exceeds the limit, but the temperature monitoring circuit 10 has not failed, the over-limit alarm circuit 20 can output a first signal alone to indicate that the temperature of the battery cell to be monitored exceeds the limit. When it is detected that the temperature monitoring circuit 10 fails, the over-limit alarm circuit 20 refuses to operate by means of switch bypass or power off, and outputs a second signal alone through the fault alarm circuit 30 to indicate that the temperature monitoring circuit 10 has failed.

[0062] In another embodiment, when it is detected that the temperature of the battery cell to be monitored exceeds the limit, but the temperature monitoring circuit 10 does not fail, the over-limit alarm circuit 20 alone outputs the first signal to indicate that the temperature of the battery cell to be monitored exceeds the limit. When it is detected that the temperature monitoring circuit 10 fails, the over-limit alarm circuit 20 outputs the first signal while the fault alarm circuit 30 outputs the second signal, and the second signal is combined with the first signal to indicate that the temperature monitoring circuit 10 fails.

[0063] In actual scenarios, the specific method used for temperature over-limit alarm indication and temperature monitoring circuit fault alarm indication is not limited here and can be set according to actual needs.

[0064] In the above scheme, the temperature of the battery cell to be monitored can be monitored by the temperature monitoring circuit 10, and output to the over-limit alarm circuit 20 and the fault alarm circuit 30 for comparison. If the over-limit alarm circuit 20 detects that the temperature of the battery cell to be monitored exceeds the limit based on the battery cell temperature, it outputs a first signal to indicate that the temperature of the battery cell to be monitored exceeds the limit; if the fault alarm circuit 30 detects that the temperature monitoring circuit 10 fails based on the battery cell temperature, it outputs a second signal to indicate that the temperature monitoring circuit 10 fails. In this scheme, the temperature monitoring circuit 10 can be monitored by the fault alarm circuit 30 while the battery cell temperature of the battery cell to be monitored is monitored by the temperature monitoring circuit 10. It can identify when the temperature of the battery cell to be monitored exceeds the limit, and can also indicate when the temperature monitoring circuit 10 fails. In this way, it can be discovered in time when the temperature monitoring circuit 10 fails, which alleviates the situation of false alarm of temperature exceeding the limit caused by the failure of the temperature monitoring circuit 10, and improves the accuracy of temperature monitoring of the battery cell.

[0065] In some embodiments, the over-limit alarm circuit 20 outputs a first signal when the battery cell temperature is greater than a preset high temperature threshold and less than a preset extreme high temperature, or when the battery cell temperature is greater than a preset extreme low temperature and less than a preset low temperature threshold; wherein the preset high temperature threshold is greater than the preset low temperature threshold, and the preset extreme high temperature is greater than the preset extreme low temperature; when the battery cell temperature is greater than the preset extreme high temperature or less than the preset extreme low temperature, the over-limit alarm circuit 20 outputs a first signal and the fault alarm circuit 30 outputs a second signal to indicate that a fault has occurred in the temperature monitoring circuit 10.

[0066] Specifically, the preset high temperature threshold represents the maximum cell temperature that can be reached when the monitored cell is operating normally; the preset low temperature threshold represents the minimum cell temperature that can be reached when the monitored cell is operating normally. The preset extreme high temperature represents the maximum cell temperature that can be reached theoretically when the monitored cell has a high temperature abnormality; the preset extreme low temperature represents the minimum cell temperature that can be reached theoretically when the monitored cell has a low temperature abnormality.

[0067] If the cell temperature output by the temperature monitoring circuit 10 is greater than the preset high temperature threshold and less than the preset high temperature limit, it means that the cell temperature output at this time is too high, but it is also within the temperature that the monitored cell can reach during operation, and it will be considered that the monitored cell has exceeded the high temperature limit. If the cell temperature output by the temperature monitoring circuit 10 is greater than the preset high temperature limit, the cell temperature output at this time is no longer within the temperature that the monitored cell can reach during operation, but the temperature monitoring circuit 10 has a fault.

[0068] Similarly, if the cell temperature output by the temperature monitoring circuit 10 is less than the preset low temperature threshold and greater than the preset limit low temperature, it means that although the cell temperature output at this time is too low, it is also a temperature that can be reached when the monitored cell is running, and it will be considered that the monitored cell has exceeded the low temperature limit. If the cell temperature output by the temperature monitoring circuit 10 is less than the preset limit low temperature, the cell temperature output at this time will no longer be the temperature that can be reached when the monitored cell is running, but the temperature monitoring circuit 10 has a fault.

[0069] Therefore, if only the over-limit alarm circuit 20 detects and outputs the first signal, it indicates that the temperature of the battery cell to be monitored is over-limit. If the over-limit alarm circuit 20 detects and outputs the first signal, and the fault alarm circuit 30 also outputs the second signal, the battery cell temperature output by the temperature monitoring circuit 10 is not only less than the preset low temperature threshold, but also less than the preset extreme low temperature; or the battery cell temperature is not only greater than the preset high temperature threshold, but also greater than the preset extreme high temperature. That is, the first signal at this time is caused by a fault in the temperature monitoring circuit 10, and the battery cell temperature of the battery cell to be monitored may not actually be over-limit.

[0070] It should be pointed out that the sizes of the preset high temperature threshold, the preset low temperature threshold, the preset extreme high temperature and the preset extreme low temperature are not unique. Depending on the type of battery cells to be monitored in the actual scenario, the sizes of the various thresholds will also be different. There is no specific limitation, as long as the preset extreme high temperature is greater than the preset high temperature threshold and the preset extreme low temperature is less than the preset low temperature threshold.

[0071] For example, in one embodiment, the preset high temperature threshold can be set to 60°C (degrees Celsius) to 80°C, that is, the preset high temperature threshold can be 60°C, 80°C, or any value between 60°C and 80°C; the preset low temperature threshold can be set to -40°C to -20°C, that is, the preset second threshold can be -40°C, -20°C, and any value between -40°C and -20°C.

[0072] In some embodiments, the preset high temperature limit can be set to the highest temperature that the temperature monitoring circuit 10 can detect (greater than or equal to the maximum temperature that the monitored battery cell can reach when it is abnormally operating at high temperature), and the preset low temperature limit can be set to the lowest temperature that the temperature monitoring circuit 10 can detect (less than or equal to the minimum temperature that the monitored battery cell can reach when it is abnormally operating at low temperature). For example, the preset high temperature limit can be set to be greater than or equal to 150°C, and the preset low temperature limit can be set to be less than or equal to -40°C.

[0073] In the above scheme, when the cell temperature output by the temperature monitoring circuit 10 is greater than the preset high temperature threshold and less than the preset high temperature limit, or greater than the preset low temperature limit and less than the preset low temperature threshold, only the over-limit alarm circuit 20 outputs the first signal; and when the cell temperature output by the temperature monitoring circuit 10 is greater than the preset high temperature limit or less than the preset low temperature limit, not only the over-limit alarm circuit 20 outputs the first signal, but also the fault alarm circuit 30 outputs the second signal. In this way, the judgment of whether the temperature monitoring circuit 10 is faulty is realized according to whether the first signal is output alone or the first signal and the second signal are output simultaneously, and the fault detection accuracy of the temperature monitoring circuit 10 is high.

[0074] See also Figure 2 In some embodiments, the second signal includes an open circuit fault signal, the fault alarm circuit 30 includes an open circuit comparison circuit 32 and a first reference signal circuit 31, the first input end of the open circuit comparison circuit 32 is connected to the temperature monitoring circuit 10, and the second input end of the open circuit comparison circuit 32 is connected to the first output end of the first reference signal circuit 31;

[0075] Among them, the first reference signal circuit 31 outputs a first reference signal representing a preset extreme low temperature through the first output terminal, and the open circuit comparison circuit 32 is used to output an open circuit fault signal when the battery cell temperature is lower than the preset extreme low temperature, and the open circuit fault signal is used to indicate that an open circuit fault occurs in the temperature monitoring circuit 10.

[0076] Specifically, the first reference signal circuit 31 is used to provide a first reference signal for characterizing a preset extreme low temperature. The type of the first reference signal is not unique and is not specifically limited. For example, it can be an electrical parameter such as voltage or current, as long as the parameter type that characterizes the battery cell temperature output by the temperature monitoring circuit is the same. The open circuit comparison circuit 32 refers to a circuit that performs a comparative analysis based on the preset extreme low temperature and the battery cell temperature, and outputs an open circuit fault signal when the battery cell temperature is less than the preset extreme low temperature.

[0077] In this embodiment, the open circuit comparison circuit 32 can compare the output of the temperature monitoring circuit with the output of the first output terminal of the first reference signal, thereby analyzing whether an open circuit fault occurs in the temperature monitoring circuit 10 .

[0078] In the above scheme, the fault alarm circuit 30 is configured with an open circuit comparison circuit 32 and a first reference signal circuit 31, and determines whether the temperature monitoring circuit 10 has an open circuit fault by comparing the comparison circuit, which has a high open circuit fault detection accuracy.

[0079] Please continue reading Figure 2 In some embodiments, the second signal includes a short-circuit fault signal, and the fault alarm circuit 30 also includes a short-circuit comparison circuit 33. The first input end of the short-circuit comparison circuit 33 is connected to the temperature monitoring circuit 10, and the second input end of the short-circuit comparison circuit 33 is connected to the second output end of the first reference signal circuit 31; wherein the first reference signal circuit 31 outputs a second reference signal representing a preset extreme high temperature through the second output end, and the short-circuit comparison circuit 33 is used to output a short-circuit fault signal when the battery cell temperature is greater than the preset extreme high temperature, and the short-circuit fault signal is used to indicate that a short-circuit fault occurs in the temperature monitoring circuit 10.

[0080] Specifically, the short-circuit comparison circuit 33 refers to a circuit that performs comparative analysis based on a preset high temperature limit and a battery cell temperature, and outputs a short-circuit fault signal when the battery cell temperature is greater than the preset high temperature limit. In this embodiment, the fault alarm circuit 30 includes not only an open-circuit comparison circuit 32, but also a short-circuit comparison circuit 33. Through the short-circuit comparison circuit 33, the output of the temperature monitoring circuit can be compared with the output of the second output terminal of the first reference signal, thereby realizing the analysis of whether a short-circuit fault occurs in the temperature monitoring circuit 10.

[0081] In the above scheme, the fault alarm circuit 30 is further configured with a short-circuit comparison circuit 33, which determines whether the temperature monitoring circuit 10 has a short-circuit fault by comparing the comparison circuit, and has a high short-circuit fault detection accuracy.

[0082] It should be pointed out that in actual scenarios, depending on the different acquisition principles of the temperature monitoring circuit 10, the comparison implementation methods of the open circuit comparison circuit 32 and the short circuit comparison circuit 33 will also be different. In one embodiment, the parameter output by the temperature monitoring circuit 10 (characterizing the battery cell temperature) decreases as the battery cell temperature increases as an example for explanation. In this embodiment, when an open circuit fault occurs, the parameter input to the first input terminal of the open circuit comparison circuit 32 will be greater than the first reference signal input to the second input terminal of the open circuit comparison circuit 32; and when a short circuit fault occurs, the second reference signal input to the second input terminal of the short circuit comparison circuit 33 will be greater than the parameter input to the first input terminal of the short circuit comparison circuit 33.

[0083] It is understood that the specific types of the open circuit comparison circuit 32 and the short circuit comparison circuit 33 are not unique, as long as the voltage comparison function can be realized and different signals can be output according to different comparison results, this type of circuit can be used. For example, in one embodiment, the comparison function of the open circuit comparison circuit 32 and the short circuit comparison circuit 33 can be realized by a processor or a controller. In another embodiment, it can also be realized by a hardware comparison circuit, which is not specifically limited.

[0084] For more details, please refer to Figure 2 The open circuit comparison circuit 32 includes a first comparator U1 and a first pull-up resistor RA, the first input end of the first comparator U1 serves as the first input end of the open circuit comparison circuit 32, the second input end of the first comparator U1 serves as the second input end of the open circuit comparison circuit 32, the first pull-up resistor RA is connected between the power supply and the output end of the first comparator U1, and the output end of the first comparator U1 serves as the output end of the open circuit comparison circuit 32. The short circuit comparison circuit 33 includes a second comparator U2 and a second pull-up resistor RB, the first input end of the second comparator U2 serves as the first input end of the short circuit comparison circuit 33, the second input end of the second comparator U2 serves as the second input end of the short circuit comparison circuit 33, the second pull-up resistor RB is connected between the power supply and the output end of the second comparator U2, and the output end of the second comparator U2 serves as the output end of the short circuit comparison circuit 33.

[0085] It should be noted that the first input terminal of the first comparator U1 can be a positive input terminal, and the second input terminal of the first comparator U1 can be a negative input terminal; or the first input terminal of the first comparator U1 can be a negative input terminal, and the second input terminal of the first comparator U1 can be a positive input terminal, and the specific details are not limited. If the first input terminal of the first comparator U1 is a positive input terminal, and the second input terminal of the first comparator U1 is a negative input terminal, when the parameter representing the battery cell temperature output by the temperature monitoring circuit 10 is greater than the first reference signal output by the first output terminal of the first reference signal circuit 31, the first comparator U1 outputs a high-level signal. Further, if the parameter output by the temperature monitoring circuit 10 decreases as the battery cell temperature increases, then when the first comparator U1 outputs a high-level signal, it indicates that the battery cell temperature is lower than the preset low temperature limit represented by the first reference signal, and at this time, the high-level signal of the first comparator U1 is used as the second signal (specifically, an open circuit fault signal). If the first input terminal of the first comparator U1 is a negative input terminal, the second input terminal of the first comparator U1 is a positive input terminal, and the electrical parameter output by the temperature monitoring circuit 10 decreases as the battery cell temperature increases, then the low-level signal output by the first comparator U1 will be used as the second signal, and the details will not be repeated.

[0086] The first input terminal of the second comparator U2 and the first input terminal of the first comparator U1 can be the same type of input terminals, for example, both are positive input terminals or negative input terminals; or they can be different types of input terminals, that is, one is a positive input terminal and the other is a negative input terminal. Moreover, the specific implementation of the second comparator U2 is similar to that of the first comparator U1, and will not be repeated here.

[0087] See also Figure 3 In some embodiments, the second signal includes a high temperature over-limit signal and a low temperature over-limit signal; the over-limit alarm circuit 20 includes a low temperature comparison circuit 22, a high temperature comparison circuit 23 and a second reference signal circuit 21, the first input end of the high temperature comparison circuit 23 and the first input end of the low temperature comparison circuit 22 are respectively connected to the temperature monitoring circuit 10, the second input end of the high temperature comparison circuit 23 is connected to the first output end of the second reference signal circuit 21, and the second input end of the low temperature comparison circuit 22 is connected to the second output end of the second reference signal circuit 21;

[0088] Among them, the first output end of the second reference signal circuit 21 outputs a third reference signal representing a preset low temperature threshold, the second output end of the second reference signal circuit 21 outputs a fourth reference signal representing a preset high temperature threshold, the high temperature comparison circuit 23 is used to output a high temperature over-limit signal when the battery cell temperature is greater than the preset high temperature threshold, and the high temperature over-limit signal is used to indicate that the temperature of the battery cell to be monitored is too high and a high temperature over-limit phenomenon occurs; the low temperature comparison circuit 22 is used to output a low temperature over-limit signal when the battery cell temperature is less than the preset low temperature threshold, and the low temperature over-limit signal is used to indicate that the temperature of the battery cell to be monitored is too low and a low temperature over-limit phenomenon occurs.

[0089] Specifically, the second reference signal circuit 21 is a circuit for providing a fourth reference signal representing a preset high temperature threshold, and a circuit for providing a third reference signal representing a preset low temperature threshold. The low temperature comparison circuit 22 refers to a circuit that compares the input parameter representing the battery cell temperature and the input third reference signal representing the preset low temperature threshold, and outputs a low temperature over-limit signal when the battery cell temperature is less than the preset low temperature threshold. The high temperature comparison circuit 23 refers to a circuit that compares the input parameter representing the battery cell temperature and the input fourth reference signal representing the preset high temperature threshold, and outputs a high temperature over-limit signal when the battery cell temperature is greater than the preset high temperature threshold.

[0090] It should be pointed out that in actual scenarios, depending on the different acquisition principles of the temperature monitoring circuit 10, the comparison implementation methods of the low temperature comparison circuit 22 and the high temperature comparison circuit 23 will also be different. In one embodiment, the parameter output by the temperature monitoring circuit 10 decreases as the battery cell temperature increases as an example for explanation. In this embodiment, when a low temperature exceeds the limit, the parameter input to the first input terminal of the low temperature comparison circuit 22 will be greater than the third reference signal input to the second input terminal of the low temperature comparison circuit 22; and when a high temperature exceeds the limit, the parameter input to the first input terminal of the high temperature comparison circuit 23 will be greater than the fourth reference signal input to the second input terminal of the high temperature comparison circuit 23.

[0091] It can be understood that the specific types of low temperature comparison circuit 22 and high temperature comparison circuit 23 are not unique. As long as the voltage comparison function can be realized and different signals are output according to the comparison results, this type of circuit can be used. For example, in one embodiment, the comparison function of low temperature comparison circuit 22 and high temperature comparison circuit 23 can be realized by a processor or a controller. In another embodiment, it can also be realized by a hardware comparison circuit, which is not specifically limited.

[0092] For more details, please refer to Figure 3 The low temperature comparison circuit 22 includes a third comparator U3 and a third pull-up resistor RC, the first input end of the third comparator U3 is used as the first input end of the low temperature comparison circuit 22, the second input end of the third comparator U3 is used as the second input end of the low temperature comparison circuit 22, the third pull-up resistor RC is connected between the power supply and the output end of the third comparator U3, and the output end of the third comparator U3 is used as the output end of the low temperature comparison circuit 22. The high temperature comparison circuit 23 includes a fourth comparator U4 and a fourth pull-up resistor RD, the first input end of the fourth comparator U4 is used as the first input end of the high temperature comparison circuit 23, the second input end of the fourth comparator U4 is used as the second input end of the high temperature comparison circuit 23, the fourth pull-up resistor RD is connected between the power supply and the output end of the fourth comparator U4, and the output end of the fourth comparator U4 is used as the output end of the high temperature comparison circuit 23.

[0093] It can be understood that the specific implementation and operation principle of the third comparator U3 and the fourth comparator U4 are similar to those of the first comparator U1, and are not elaborated herein.

[0094] In the above scheme, the over-limit alarm circuit 20 is configured with a low-temperature comparison circuit 22, a high-temperature comparison circuit 23 and a second reference signal circuit 21, which can detect both high-temperature over-limit and low-temperature over-limit, and has high reliability in temperature over-limit detection.

[0095] It should be noted that the types of the first reference signal circuit 31 and the second reference signal circuit 21 are not unique. In some embodiments, taking the temperature monitoring circuit 10 using a voltage signal to characterize the cell temperature as an example, a voltage source + voltage converter can be used to respectively construct the first reference signal circuit 31 and the second reference signal circuit 21. In other embodiments, the first reference signal circuit 31 and the second reference signal circuit 21 can also be constructed in the form of multi-stage voltage division, which is not specifically limited.

[0096] In another embodiment, the temperature monitoring circuit 10 is constructed based on the principle that the resistance of the thermistor changes with temperature. Accordingly, the principle of parallel shunt can be adopted to connect the thermistor in parallel with other resistive loads, and the resistance of the branch where the thermistor is located can be changed by temperature change. When the voltage at both ends remains unchanged, the current in the branch where the thermistor is located changes with temperature, so the current signal can also represent the battery core temperature.

[0097] See also Figure 4 In some embodiments, taking the temperature monitoring circuit 10 using a voltage signal to characterize the battery cell temperature as an example, the first reference signal circuit 31 includes a voltage source (VCC shown in the figure), a first resistor R1, a second resistor R2 and a third resistor R3, the voltage source is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the common end formed by the first resistor R1 and the second resistor R2 serves as the first output end of the first reference signal circuit 31, the second end of the second resistor R2 is connected to the first end of the third resistor R3, and the common end formed by the second resistor R2 and the third resistor R3 serves as the second output end of the first reference signal circuit 31, and the second end of the third resistor R3 is grounded.

[0098] Specifically, the present embodiment is constructed in the form of two-stage voltage division to obtain the first reference signal circuit 31, which specifically includes a voltage source, a first resistor R1, a second resistor R2 and a third resistor R3 connected in series, and the terminal led out of the connection between the first resistor R1 and the second resistor R2 is the first output terminal of the first reference signal circuit 31; the terminal led out of the connection between the second resistor R2 and the third resistor R3 is the second output terminal of the first reference signal circuit 31. Accordingly, the first reference signal circuit 31 can provide reference voltages of different magnitudes for the open circuit comparison circuit and the short circuit comparison circuit.

[0099] It should be noted that the size of the voltage source is not unique and can be selected according to the actual scenario. For example, in one embodiment, a voltage source with a voltage value of 5V (volts) can be selected. The resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 are not unique. Specifically, the voltage values ​​corresponding to the preset extreme high temperature and the preset extreme low temperature (under the temperature and voltage conversion relationship of the temperature monitoring circuit 10), the voltage size of the voltage source, and the voltage dividing principle of the series voltage dividing circuit can be combined to match the first resistor R1, the second resistor R2, and the third resistor R3 with appropriate resistance values. The specific details are not repeated.

[0100] The above scheme, in the form of a voltage divider circuit, provides voltages corresponding to the preset extreme low temperature and the preset extreme high temperature for the open circuit comparison circuit 32 and the short circuit comparison circuit 33 at the same time, and realizes fault detection of the temperature monitoring circuit 10 in the form of a voltage signal. While improving the detection accuracy, it can also effectively reduce the circuit volume and save circuit costs.

[0101] and / or, in some embodiments, see Figure 4 The second reference signal circuit 21 includes a voltage source (VCC shown in the figure), a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, the voltage source is connected to a first end of the fourth resistor R4, a second end of the fourth resistor R4 is connected to a first end of the fifth resistor R5, and a common end formed by the fourth resistor R4 and the fifth resistor R5 serves as a first output end of the second reference signal circuit 21, a second end of the fifth resistor R5 is connected to a first end of the sixth resistor R6, and a common end formed by the fifth resistor R5 and the sixth resistor R6 serves as a second output end of the second reference signal circuit 21, and a second end of the sixth resistor R6 is grounded.

[0102] Similarly, in this embodiment, the second reference signal circuit 21 is constructed in the form of a two-stage voltage division. The second reference signal circuit 21 specifically includes a voltage source, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6 connected in series. The terminal led out by the connection between the fourth resistor R4 and the fifth resistor R5 is the first output end of the second reference signal circuit 21; the terminal led out by the connection between the fifth resistor R5 and the sixth resistor R6 is the second output end of the second reference signal circuit 21.

[0103] Similarly, the size of the voltage source is not unique, and can be selected according to the actual scenario. For example, in one embodiment, a voltage source with a voltage value of 5V can be selected. The resistance values ​​of the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are not unique. Specifically, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 can be matched with appropriate resistance values ​​in combination with the voltage values ​​corresponding to the preset high temperature threshold and the preset low temperature threshold, the voltage size of the voltage source, and the voltage dividing principle of the series voltage dividing circuit. The specific details are not repeated.

[0104] The above scheme, in the form of a voltage divider circuit, provides voltages corresponding to a preset low temperature threshold and a preset high temperature threshold for the low temperature comparison circuit 22 and the high temperature comparison circuit 23 at the same time. The implementation method is simple. While providing an accurate reference voltage, it can also effectively reduce the circuit volume and save circuit costs.

[0105] See also Figure 5 In some embodiments, the battery management system further includes a fault alarm 40; the output end of the open circuit comparison circuit 32 and the output end of the short circuit comparison circuit 33 are respectively connected to the fault alarm 40.

[0106] And / or, in some embodiments, the battery management system further includes an over-limit alarm 50 , and the output end of the low-temperature comparison circuit 22 and the output end of the high-temperature comparison circuit 23 are respectively connected to the over-limit alarm 50 .

[0107] Specifically, the fault alarm 40 can output an alarm signal in the form of sound, light, etc. to prompt the device that the temperature monitoring circuit 10 has a fault; the over-limit alarm 50 can also output an alarm signal in the form of sound, light, etc. to prompt the device that the battery cell temperature exceeds the limit value.

[0108] It should be pointed out that the types of the fault alarm 40 and the over-limit alarm 50 are not unique, as long as both can output alarm signals in different signal forms. Specifically, the types of the fault alarm 40 and the over-limit alarm 50 can be the same (as long as the output signal forms are different) or different, and there is no specific limitation.

[0109] For example, in one embodiment, the fault alarm 40 and the over-limit alarm 50 are both light emitting diodes, the difference being that the colors emitted when the fault alarm is performed are different. In another embodiment, the fault alarm 40 and the over-limit alarm 50 can also be buzzers, the difference being that the frequencies of the vibration sounds of the two are different.

[0110] In the above scheme, the battery management system also includes a fault alarm 40 and / or an over-limit alarm 50, which realizes a temperature over-limit alarm and / or a temperature monitoring circuit 10 fault alarm in the form of an alarm, which is helpful for the user to know the actual operating status of the monitored battery cell and the temperature monitoring circuit 10 in time.

[0111] In some embodiments, the number of battery cells to be monitored is multiple, and the number of fault alarms 40 is one; each battery cell to be monitored is respectively provided with an open circuit comparison circuit 32, a short circuit comparison circuit 33 and a first reference signal circuit 31, and each open circuit comparison circuit 32 and each short circuit comparison circuit 33 are respectively connected to the fault alarm 40.

[0112] And / or, in some embodiments, the number of battery cells to be monitored is multiple, and the number of over-limit alarms 50 is one; each battery cell to be monitored is respectively provided with a low-temperature comparison circuit 22, a high-temperature comparison circuit 23 and a second reference signal circuit 21, and each low-temperature comparison circuit 22 and each high-temperature comparison circuit 23 are respectively connected to the over-limit alarm 50.

[0113] Specifically, in order to realize the temperature monitoring of multiple cells to be monitored, it is necessary to configure a temperature monitoring circuit 10 for each cell to be monitored, which will not be described in detail here. Figure 6 , this embodiment is explained by taking two monitoring cells as an example, each cell to be monitored is equipped with an open circuit comparison circuit 32, a short circuit comparison circuit 33 and a first reference signal circuit 31, but the fault alarm 40 shares one. And / or each cell to be monitored is equipped with a low temperature comparison circuit 22, a high temperature comparison circuit 23 and a second reference signal circuit 21, but the over-limit alarm 50 shares one.

[0114] In the above scheme, when there are multiple battery cells to be monitored, a fault alarm 40 and / or an over-limit alarm 50 can be shared. While realizing the fault alarm and / or over-limit alarm of any battery cell to be monitored, the cost of the alarm and the circuit volume can be reduced.

[0115] In some embodiments, there are multiple battery cells to be monitored, and the number of fault alarms 40 is consistent with the number of battery cells to be monitored; each battery cell to be monitored is respectively provided with an open circuit comparison circuit 32, a short circuit comparison circuit 33 and a first reference signal circuit 31, and each open circuit comparison circuit 32 and short circuit comparison circuit 33 of the battery cell to be monitored are connected to a fault alarm 40.

[0116] And / or, in some embodiments, there are multiple battery cells to be monitored, and the number of over-limit alarms 50 is consistent with the number of battery cells to be monitored; each battery cell to be monitored is respectively provided with a low-temperature comparison circuit 22, a high-temperature comparison circuit 23 and a second reference signal circuit 21, and each low-temperature comparison circuit 22 and high-temperature comparison circuit 23 of the battery cell to be monitored are connected to an over-limit alarm 50.

[0117] Specifically, in the solution of this embodiment, when there are multiple cells to be monitored, an over-limit alarm 50 and / or a fault alarm 40 can be configured for each cell to be monitored, so that the temperature over-limit alarm and / or the temperature monitoring circuit 10 fault alarm of each cell to be monitored are respectively carried out. When the temperature of multiple cells to be monitored exceeds the limit or the temperature monitoring circuit 10 fails, the alarms can be respectively issued, so as to intuitively obtain the cells to be monitored with the temperature over-limit or the cells with the temperature monitoring circuit 10 failure, that is, to achieve fault location.

[0118] In the above scheme, when there are multiple battery cells to be monitored, a fault alarm 40 can be set for each battery cell to be monitored, and / or an over-limit alarm 50 can be set for each battery cell to be monitored. In this way, when the temperature exceeds the limit or the temperature monitoring circuit 10 fails, the fault location can be achieved and the temperature monitoring accuracy can be improved.

[0119] See also Figure 7 In some embodiments, the fault alarm 40 includes an open circuit alarm 42 and a short circuit alarm 41 , the output end of the open circuit comparison circuit 32 is connected to the open circuit alarm 42 , and the output end of the short circuit comparison circuit 33 is connected to the short circuit alarm 41 .

[0120] And / or, in some embodiments, the over-limit alarm 50 includes a low temperature alarm 52 and a high temperature alarm 51 , the output end of the low temperature comparison circuit 22 is connected to the low temperature alarm 52 , and the output end of the high temperature comparison circuit 23 is connected to the high temperature alarm 51 .

[0121] Specifically, the scheme of this embodiment further divides the fault alarm 40 into an open circuit alarm 42 and a short circuit alarm 41, and / or divides the over-limit alarm 50 into a low temperature alarm 52 and a high temperature alarm 51. The open circuit alarm 42 is connected to the open circuit comparison circuit 32, and the short circuit alarm 41 is connected to the short circuit comparison circuit 33; and / or, the low temperature alarm 52 is connected to the low temperature comparison circuit 22, and the high temperature alarm 51 is connected to the high temperature comparison circuit 23. In this way, when an over-limit alarm occurs, it can be further distinguished whether the temperature is too low or too high at this time, or when a fault alarm occurs, it can be further distinguished whether it is a short circuit fault or an open circuit fault at this time.

[0122] In the above scheme, different alarms are used to realize open circuit fault and short circuit fault respectively, and / or different alarms are used to realize low temperature exceeding limit and high temperature exceeding limit respectively, so that the alarm type of the temperature monitoring circuit can be accurately known, thereby improving the alarm reliability of the battery management system.

[0123] In some embodiments, there are multiple battery cells to be monitored, and the number of open circuit alarms 42 and short circuit alarms 41 are both one; each battery cell to be monitored is respectively provided with an open circuit comparison circuit 32, a short circuit comparison circuit 33 and a first reference signal circuit 31, and each open circuit comparison circuit 32 is respectively connected to the open circuit alarm 42, and each short circuit comparison circuit 33 is respectively connected to the short circuit alarm 41.

[0124] And / or, in some embodiments, the number of battery cells to be monitored is multiple, and the number of low-temperature alarms 52 and high-temperature alarms 51 are both one; each battery cell to be monitored is respectively provided with a low-temperature comparison circuit 22, a high-temperature comparison circuit 23 and a second reference signal circuit 21, each low-temperature comparison circuit 22 is respectively connected to the low-temperature alarm 52, and each high-temperature comparison circuit 23 is respectively connected to the high-temperature alarm 51.

[0125] Specifically, in the scheme of the present embodiment, the number of battery cells to be monitored can be multiple, and each battery cell to be monitored is configured with an open circuit comparison circuit 32, a short circuit comparison circuit 33 and a first reference signal circuit 31, but the open circuit alarms of the battery cells to be monitored share one open circuit alarm 42, and all the open circuit comparison circuits 32 of the battery cells to be monitored are connected to the same open circuit alarm 42; the short circuit alarms of the battery cells to be monitored share one short circuit alarm 41, and all the short circuit comparison circuits 33 of the battery cells to be monitored are connected to the same short circuit alarm 41.

[0126] And / or, the low temperature alarms of each battery cell to be monitored share a low temperature alarm 52, and the low temperature comparison circuits 22 of all battery cells to be monitored are connected to the same low temperature alarm 52; the high temperature alarms of each battery cell to be monitored share a high temperature alarm 51, and the high temperature comparison circuits 23 of all battery cells to be monitored are connected to the same high temperature alarm 51.

[0127] In the above scheme, when the number of battery cells to be monitored is multiple, an alarm can be set for short circuit fault alarm, open circuit fault alarm, high temperature over-limit alarm and low temperature over-limit alarm respectively. While improving the accuracy of the alarm type, it can also reduce the circuit volume and save circuit costs.

[0128] In some embodiments, there are multiple battery cells to be monitored, and the number of open circuit alarms 42 and short circuit alarms 41 is consistent with the number of battery cells to be monitored; each battery cell to be monitored is respectively provided with an open circuit comparison circuit 32, a short circuit comparison circuit 33 and a first reference signal circuit 31, each open circuit comparison circuit 32 is connected to an open circuit alarm 42, and each short circuit comparison circuit 33 is connected to a short circuit alarm 41.

[0129] And / or, in some embodiments, there are multiple battery cells to be monitored, and the number of low-temperature alarms 52 and high-temperature alarms 51 is consistent with the number of battery cells to be monitored; each battery cell to be monitored is respectively provided with a low-temperature comparison circuit 22, a high-temperature comparison circuit 23 and a second reference signal circuit 21, each low-temperature comparison circuit 22 is connected to a low-temperature alarm 52, and each high-temperature comparison circuit 23 is connected to a high-temperature alarm 51.

[0130] Specifically, when there are multiple cells to be monitored, an open circuit alarm 42 and a short circuit alarm 41 can be configured for each cell to be monitored, and / or a low temperature alarm 52 and a high temperature alarm 51 can be configured for each cell to be monitored, so that each cell to be monitored can be alarmed for over-temperature or under-temperature, and for open circuit or short circuit respectively. Therefore, when the temperature of multiple cells to be monitored exceeds the limit or the temperature monitoring circuit 10 fails, different alarm prompts can be given to different cells in combination with the actual detection results, so as to intuitively obtain the cells with over-temperature, the cells with under-temperature, the cells with short circuit in the temperature monitoring circuit 10, and the cells with open circuit in the temperature monitoring circuit 10.

[0131] In the above scheme, when the number of battery cells to be monitored is multiple, an alarm can be set for the short circuit fault alarm and open circuit fault alarm of each battery cell to be monitored, and / or an alarm can be set for the high temperature over-limit alarm and low temperature over-limit alarm of each battery cell to be monitored. While improving the accuracy of the alarm type, the alarm position can also be accurately located, further improving the alarm reliability.

[0132] See also Figure 8 In some embodiments, the temperature monitoring circuit 10 includes a pull-up resistor R and a thermistor RS, the first end of the pull-up resistor R is connected to a pull-up power supply, the second end of the pull-up resistor R is connected to a first end of the thermistor RS, the second end of the thermistor RS is grounded, and the over-limit alarm circuit 20 and the fault alarm circuit 30 are respectively connected to the first end of the thermistor RS.

[0133] Specifically, a thermistor RS is a resistor whose resistance value changes with the change of temperature. In this embodiment, the temperature monitoring circuit 10 is constructed in the form of a pure hardware circuit. The type of thermistor RS is not unique. It can be a positive temperature coefficient thermistor RS (PTC) or a negative temperature coefficient thermistor RS (Negative Temperature Coefficient, NTC). There is no specific limitation. For the sake of ease of understanding, this application can be understood as a negative temperature coefficient thermistor RS. A voltage divider circuit is formed by constructing a pull-up resistor R and a thermistor RS. According to the different temperatures of the battery cell to be monitored, the thermistor RS will change accordingly, resulting in a change in the voltage divider, and different voltage dividers represent different battery cell temperatures.

[0134] It can be understood that in other embodiments, the temperature monitoring circuit 10 can also be constructed in the form of a temperature sensor, a processor and a voltage converter. In this case, the processor stores voltage parameters corresponding to different battery cell temperatures. After the battery cell temperature is collected, the required voltage is matched and converted by controlling the voltage converter, and then output to the over-limit alarm circuit 20 and the fault alarm circuit 30.

[0135] The above solution uses the thermistor RS and the pull-up resistor R to divide the voltage and convert the cell temperature of the monitored cell into a voltage parameter, thereby realizing temperature monitoring, which has high temperature acquisition accuracy and convenience.

[0136] See also Fig. 9 In some embodiments, the temperature monitoring circuit 10 further includes an RC filter circuit 11, the over-limit alarm circuit 20 and the fault alarm circuit 30 are respectively connected to the RC filter circuit 11, and the RC filter circuit 11 is connected to the first end of the thermistor RS.

[0137] Specifically, the RC filter circuit 11 is also a resistor-capacitance filter circuit. In the solution of this embodiment, an RC filter circuit 11 is connected in series at the voltage-dividing output end of the voltage-dividing acquisition structure to filter the collected voltage-dividing signal, and after obtaining the voltage parameter corresponding to the battery cell temperature, it is sent to the over-limit alarm circuit 20 and the fault alarm circuit 30.

[0138] In more detail, in one embodiment, the RC filter circuit 11 specifically includes a resistor and a capacitor, the first end of the resistor is connected to the first end of the thermistor RS, the second end of the resistor is connected to the first end of the capacitor and the over-limit alarm circuit 20 and the fault alarm circuit 30, and the second end of the capacitor is grounded.

[0139] In the above scheme, after the voltage is collected by the voltage-dividing sampling circuit composed of the thermistor RS and the pull-up resistor R, it is also necessary to filter the voltage through the RC filter circuit 11 and then output to the over-limit alarm circuit 20 and the fault alarm circuit 30, so as to further improve the accuracy of temperature collection.

[0140] In order to facilitate understanding of the technical solution of the present application, the present application is explained below in conjunction with more detailed embodiments.

[0141] The battery management system includes a temperature monitoring circuit 10, an over-limit alarm circuit 20, a fault alarm circuit 30, a fault alarm 40 and an over-limit alarm 50. The temperature monitoring circuit 10 includes a pull-up resistor R, an NTC thermistor RS and an RC filter circuit 11; the over-limit alarm circuit 20 includes a low-temperature comparison circuit 22, a high-temperature comparison circuit 23 and a second reference signal circuit 21; the fault alarm circuit 30 includes an open circuit comparison circuit 32, a short circuit comparison circuit 33 and a first reference signal circuit 31; the fault alarm 40 includes a short circuit alarm 41 connected to the short circuit comparison circuit 33, and an open circuit alarm 42 connected to the open circuit comparison circuit 32; the over-limit alarm 50 includes a low-temperature alarm 52 connected to the low-temperature comparison circuit 22, and a high-temperature alarm 51 connected to the high-temperature comparison circuit 23. Further, the open circuit comparison circuit 32, the short circuit comparison circuit 33, the low-temperature comparison circuit 22 and the high-temperature comparison circuit 23 are all implemented in the form of hardware circuits (comparators).

[0142] For any monitored battery cell, a temperature monitoring circuit 10, an over-limit alarm circuit 20, a fault alarm circuit 30, a short circuit alarm 41, an open circuit alarm 42, a low temperature alarm 52 and a high temperature alarm 51 are respectively provided, taking any monitored battery cell as an example.

[0143] According to the different cell temperatures of the cells to be monitored, the NTC thermistor RS exhibits different resistance values, and then the voltage parameters that can represent the cell temperature are obtained through voltage division and sent to the over-limit alarm circuit 20 and the fault alarm circuit 30. Through the first reference signal circuit 31 of the fault alarm circuit 30, the voltage representing -40°C (that is, the voltage division size that the temperature monitoring circuit 10 can output when the thermistor RS collects the temperature of -40°C) and the voltage representing 150°C (that is, the voltage division size that the temperature monitoring circuit 10 can output when the thermistor RS collects the temperature of 150°C) are input to the second input end of the open circuit comparison circuit 32 and the second input end of the short circuit comparison circuit 33, respectively.

[0144] Through the second reference signal circuit 21 of the over-limit alarm circuit 20, a voltage representing -20°C (that is, the magnitude of the voltage division that the temperature monitoring circuit 10 can output when the thermistor RS collects the temperature of -20°C) and a voltage representing 60°C (that is, the magnitude of the voltage division that the temperature monitoring circuit 10 can output when the thermistor RS collects the temperature of 60°C) are respectively input into the second input end of the low-temperature comparison circuit 22 and the second input end of the high-temperature comparison circuit 23.

[0145] After that, the temperature monitoring circuit 10 collects the battery cell temperature in real time, and the voltage parameters characterizing the battery cell temperature obtained through the collection are respectively input into the first input end of the low temperature comparison circuit 22, the second input end of the high temperature comparison circuit 23, the first input end of the open circuit comparison circuit 32, and the second input end of the short circuit comparison circuit 33.

[0146] When the cell temperature does not exceed the range of the preset low limit to the preset high limit, if the cell temperature is too high, the voltage parameter divided by the NTC thermistor RS will be lower than the voltage input to the second input terminal of the high temperature comparison circuit 23 (that is, the voltage corresponding to 60°C), and the high temperature comparison circuit 23 outputs a high temperature limit signal (specifically, a high level signal), causing the high temperature alarm 51 connected thereto to alarm (for example, light up). If the cell temperature is too low, the voltage parameter divided by the NTC thermistor RS will be greater than the voltage input to the second input terminal of the low temperature comparison circuit 22 (that is, the voltage corresponding to -20°C), and the low temperature comparison circuit 22 outputs a low temperature limit signal (also a high level signal), causing the low temperature alarm 52 connected thereto to alarm (for example, light up).

[0147] When the cell temperature exceeds the preset low temperature limit and the preset high temperature limit, that is, is less than the preset low temperature limit or greater than the preset high temperature limit, the over-limit alarm circuit 20, the low temperature alarm 52 and the high temperature alarm 51 will perform similar alarms as described above. In addition, if the cell temperature is higher than the preset high temperature limit, the voltage parameter divided by the NTC thermistor RS will be lower than the voltage input to the second input terminal of the short-circuit comparison circuit 33 (that is, the voltage corresponding to 150°C), and the short-circuit comparison circuit 33 outputs a short-circuit fault signal (high-level signal), causing the short-circuit alarm 41 connected thereto to alarm. If the cell temperature is lower than the preset low temperature limit, the voltage parameter divided by the NTC thermistor RS will be lower than the voltage input to the second input terminal of the open circuit comparison circuit 32 (that is, the voltage corresponding to -40°C), and the open circuit comparison circuit 32 outputs an open circuit fault signal (high-level signal), causing the open circuit alarm 42 connected thereto to alarm.

[0148] In some embodiments, the present application also provides a battery device, including at least one battery cell and the above-mentioned battery management system.

[0149] Specifically, the structure and implementation of the battery management system are as shown in the above-mentioned embodiments and the accompanying drawings, and will not be repeated here. The battery device can monitor the cell temperature of the cell to be monitored through the temperature monitoring circuit 10, and output it to the over-limit alarm circuit 20 and the fault alarm circuit 30 for comparison. If the over-limit alarm circuit 20 detects that the temperature of the cell to be monitored exceeds the limit based on the cell temperature, it outputs a first signal to indicate that the temperature of the cell to be monitored exceeds the limit; if the fault alarm circuit 30 detects that the temperature monitoring circuit 10 fails based on the cell temperature, it outputs a second signal to indicate that the temperature monitoring circuit 10 fails. In this solution, the temperature monitoring circuit 10 can be monitored by the fault alarm circuit 30 while the cell temperature of the cell to be monitored is monitored by the temperature monitoring circuit 10, so that it can be identified when the temperature of the cell to be monitored exceeds the limit, and it can also indicate when the temperature monitoring circuit 10 fails. In this way, it can be discovered in time when the temperature monitoring circuit 10 fails, which alleviates the situation of false alarm of temperature exceeding the limit caused by the failure of the temperature monitoring circuit 10, and improves the accuracy of temperature monitoring of the cell.

[0150] 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 battery management system, characterized in that: include: A temperature monitoring circuit is provided in the battery cell to be monitored, and is used to monitor the battery cell temperature of the battery cell to be monitored; an over-limit alarm circuit, connected to the temperature monitoring circuit, and configured to output a first signal when it is detected based on the battery cell temperature that the temperature of the battery cell to be monitored exceeds the limit, wherein the first signal indicates that the temperature of the battery cell to be monitored exceeds the limit; A fault alarm circuit is connected to the temperature monitoring circuit and is used to output a second signal when a fault in the temperature monitoring circuit is detected based on the battery core temperature, wherein the second signal indicates that a fault has occurred in the temperature monitoring circuit.

2. The battery management system according to claim 1, characterized in that: The over-limit alarm circuit outputs the first signal when the battery cell temperature is greater than a preset high temperature threshold and less than a preset high temperature limit, or when the battery cell temperature is greater than a preset low temperature limit and less than a preset low temperature threshold; wherein the preset high temperature threshold is greater than the preset low temperature threshold, and the preset high temperature limit is greater than the preset low temperature limit; When the battery cell temperature is greater than the preset high limit temperature or less than the preset low limit temperature, the over-limit alarm circuit outputs the first signal and the fault alarm circuit outputs the second signal to indicate that a fault has occurred in the temperature monitoring circuit.

3. The battery management system according to claim 2, characterized in that: The second signal includes an open circuit fault signal, the fault alarm circuit includes an open circuit comparison circuit and a first reference signal circuit, the first input end of the open circuit comparison circuit is connected to the temperature monitoring circuit, and the second input end of the open circuit comparison circuit is connected to the first output end of the first reference signal circuit; Among them, the first reference signal circuit outputs a first reference signal representing the preset extreme low temperature through the first output terminal, and the open circuit comparison circuit is used to output an open circuit fault signal when the battery cell temperature is lower than the preset extreme low temperature, and the open circuit fault signal is used to indicate that an open circuit fault occurs in the temperature monitoring circuit.

4. The battery management system according to claim 3, characterized in that: The second signal includes a short-circuit fault signal, the fault alarm circuit further includes a short-circuit comparison circuit, a first input end of the short-circuit comparison circuit is connected to the temperature monitoring circuit, and a second input end of the short-circuit comparison circuit is connected to the second output end of the first reference signal circuit; Among them, the first reference signal circuit outputs a second reference signal representing the preset extreme high temperature through the second output terminal, and the short-circuit comparison circuit is used to output a short-circuit fault signal when the battery cell temperature is greater than the preset extreme high temperature, and the short-circuit fault signal is used to indicate that a short-circuit fault occurs in the temperature monitoring circuit.

5. The battery management system according to claim 4, characterized in that: The temperature monitoring circuit uses a voltage signal to characterize the battery cell temperature; the first reference signal circuit includes a voltage source, a first resistor, a second resistor and a third resistor, the voltage source is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor, and the common end formed by the first resistor and the second resistor serves as the first output end of the first reference signal circuit, the second end of the second resistor is connected to the first end of the third resistor, and the common end formed by the second resistor and the third resistor serves as the second output end of the first reference signal circuit, and the second end of the third resistor is grounded.

6. The battery management system according to claim 4, characterized in that: The battery management system also includes a fault alarm, and the output end of the open circuit comparison circuit and the output end of the short circuit comparison circuit are respectively connected to the fault alarm; the fault alarm is used to perform an alarm operation when receiving the open circuit fault signal or the short circuit fault signal.

7. The battery management system according to claim 6, characterized in that: The number of the battery cells to be monitored is multiple, and the number of the fault alarm is one; Each of the battery cells to be monitored is respectively provided with an open circuit comparison circuit, a short circuit comparison circuit and a first reference signal circuit, and each of the open circuit comparison circuits and each of the short circuit comparison circuits are respectively connected to the fault alarm.

8. The battery management system according to claim 6, characterized in that: The number of the battery cells to be monitored is multiple, and the number of the fault alarms is consistent with the number of the battery cells to be monitored; Each of the battery cells to be monitored is respectively provided with an open circuit comparison circuit, a short circuit comparison circuit and a first reference signal circuit, and the open circuit comparison circuit and the short circuit comparison circuit of each of the battery cells to be monitored are both connected to a fault alarm.

9. The battery management system according to claim 6, characterized in that: The fault alarm includes an open circuit alarm and a short circuit alarm; The output end of the open circuit comparison circuit is connected to the open circuit alarm, and the output end of the short circuit comparison circuit is connected to the short circuit alarm. The open circuit alarm is used to perform an alarm operation when receiving the open circuit fault signal, and the short circuit alarm is used to perform an alarm operation when receiving the short circuit fault signal.

10. The battery management system according to claim 9, characterized in that: The number of the battery cells to be monitored is multiple, and the number of the open circuit alarm and the short circuit alarm are both one; Each of the battery cells to be monitored is respectively provided with an open circuit comparison circuit, a short circuit comparison circuit and a first reference signal circuit. Each of the open circuit comparison circuits is respectively connected to the open circuit alarm, and each of the short circuit comparison circuits is respectively connected to the short circuit alarm.

11. The battery management system according to claim 9, characterized in that: The number of the battery cells to be monitored is multiple, and the number of the open circuit alarms and the short circuit alarms are consistent with the number of the battery cells to be monitored; Each of the battery cells to be monitored is respectively provided with an open circuit comparison circuit, a short circuit comparison circuit and a first reference signal circuit. Each of the open circuit comparison circuits is connected to an open circuit alarm, and each of the short circuit comparison circuits is connected to a short circuit alarm.

12. The battery management system according to any one of claims 1 to 11, characterized in that: The temperature monitoring circuit includes a pull-up power supply, a pull-up resistor and a thermistor, wherein a first end of the pull-up resistor is connected to the pull-up power supply, a second end of the pull-up resistor is connected to a first end of the thermistor, a second end of the thermistor is grounded, and the fault alarm circuit is connected to the first end of the thermistor.

13. The battery management system according to claim 12, characterized in that: The temperature monitoring circuit further includes an RC filter circuit, and the fault alarm circuit is connected to the first end of the thermistor through the RC filter circuit.

14. A battery device, characterized in that: The invention comprises at least one battery cell and the battery management system according to any one of claims 1 to 13.

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