Detection circuit of low-voltage battery, battery management system and electric device

Abstract

The application provides a low-voltage battery detection circuit, a battery management system and a power consumption device. In the case that the BMS is in a sleep state, the temperature detection module of the low-voltage battery detection circuit can detect the temperature of at least one switch on the charge-discharge circuit where the low-voltage battery is located and output a temperature signal, the current detection module can detect the current of at least one switch on the charge-discharge circuit where the low-voltage battery is located and output a voltage signal, and the wake-up detection module can output a wake-up signal to the controller to wake up the controller to process the abnormality in the case that the amplitude of the temperature signal meets the over-temperature amplitude condition and / or the voltage signal meets the over-current amplitude condition, so that the abnormality of the low-voltage battery can be more accurately and effectively detected, the controller can be more timely woken up to process the abnormality, and the safety and stable operation of the low-voltage battery and the power consumption device where the low-voltage battery is located are ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a detection circuit, battery management system and electrical equipment for a low-voltage battery. Background Technology

[0002] Low-voltage batteries are an important component of various electrical devices such as electric vehicles and electronic equipment. The stable operation of low-voltage batteries is crucial to the safety and stability of the entire electrical device. A Battery Management System (BMS) can monitor the operating status of low-voltage batteries and, in the event of abnormalities such as overcurrent, overvoltage, or overtemperature, the controller in the BMS can promptly handle these abnormalities.

[0003] In existing technologies, the Battery Management System (BMS) switches to a sleep state in some situations to save power. If the low-voltage battery malfunctions, the BMS controller will be unable to handle the anomaly, posing a serious safety hazard. Therefore, how to detect the low-voltage battery while the BMS is in sleep mode is a technical problem that needs to be solved in this field. Utility Model Content

[0004] This application provides a detection circuit for a low-voltage battery, a battery management system, and an electrical device. In the case of the BMS being in a dormant state, the temperature and current of at least one switch in the charging and discharging circuit of the low-voltage battery are detected, and the controller is promptly woken up to handle the abnormality when an abnormality is detected, thereby eliminating the safety hazards of the low-voltage battery and the electrical device in which it is located.

[0005] A first aspect of this application provides a detection circuit for a low-voltage battery, comprising: a temperature detection module for detecting the temperature of at least one switch in the charging and discharging circuit of the low-voltage battery and outputting a temperature signal to a wake-up detection module, the amplitude of the temperature signal being related to the temperature of the at least one switch; a current detection module for detecting the voltage of the at least one switch and outputting a voltage signal to the wake-up detection module, the amplitude of the voltage signal being related to the current in the charging and discharging circuit; and a wake-up detection module for outputting a wake-up signal to a controller of a battery management system when the amplitude of the temperature signal meets an over-temperature amplitude condition and / or the amplitude of the voltage signal meets an over-current amplitude condition, the wake-up signal being used to wake up the controller in a dormant state.

[0006] In one embodiment of the first aspect of this application, the temperature detection module is disposed between the charging switch and the discharging switch in the charging and discharging circuit, and is respectively attached to the charging switch and the discharging switch; the temperature detection module is used to detect the temperature of the charging switch and the temperature of the discharging switch.

[0007] In one embodiment of the first aspect of this application, the temperature detection module includes: a negative temperature coefficient (NTC) temperature sensor, wherein the amplitude of the temperature signal output by the NTC temperature sensor is negatively correlated with the temperature of the at least one switch.

[0008] In one embodiment of the first aspect of this application, the over-temperature amplitude condition includes: the amplitude of the temperature signal is less than or equal to a first threshold.

[0009] In one embodiment of the first aspect of this application, the wake-up detection module includes: a first comparator, wherein a first input terminal of the first comparator is used to receive the temperature signal, a second input terminal is used to receive a comparison signal corresponding to the first threshold, and an output terminal is used to output the wake-up signal.

[0010] In one embodiment of the first aspect of this application, it further includes: a first signal processing module, wherein the temperature detection module is connected to the wake-up detection module through the first signal processing module; the first signal processing module is configured to acquire the temperature signal, process the temperature signal, and output the processed temperature signal to the wake-up detection module; wherein the processing of the temperature signal includes one or more of filtering processing and delay processing.

[0011] In one embodiment of the first aspect of this application, the current detection module includes: a first voltage acquisition unit, used to acquire a first voltage and a second voltage across a charging switch and a discharging switch arranged adjacently on the charging and discharging circuit, and output a first voltage signal and a second voltage signal to the wake-up detection module; the overcurrent amplitude condition includes: the difference between the amplitudes of the first voltage signal and the second voltage signal is greater than or equal to a second threshold.

[0012] In one embodiment of the first aspect of this application, the wake-up detection module includes: a second comparator, wherein a first input terminal of the second comparator is used to receive the first voltage signal and the second voltage signal, a second input terminal is used to receive a comparison signal corresponding to the second threshold, and an output terminal is used to output the wake-up signal.

[0013] In one embodiment of the first aspect of this application, the current detection module includes: a second voltage acquisition unit, used to acquire a third voltage and a second voltage at both ends of the discharge switch on the charging and discharging circuit, and output a third voltage signal and a second voltage signal to the wake-up detection module; the overcurrent amplitude condition includes: the difference between the amplitudes of the third voltage signal and the second voltage signal is greater than or equal to a third threshold.

[0014] In one embodiment of the first aspect of this application, the wake-up detection module includes: a third comparator, wherein a first input terminal of the third comparator is used to receive the third voltage signal and the second voltage signal, a second input terminal is used to receive a comparison signal corresponding to the third threshold, and an output terminal is used to output the wake-up signal.

[0015] In one embodiment of the first aspect of this application, the current detection module includes: a third voltage acquisition unit, used to acquire the third voltage and the first voltage at both ends of the charging switch on the charging and discharging circuit, and output the third voltage signal and the first voltage signal to the wake-up detection module; the overcurrent amplitude condition includes: the difference between the amplitudes of the first voltage signal and the third voltage signal is greater than or equal to a fourth threshold.

[0016] In one embodiment of the first aspect of this application, the wake-up detection module includes: a fourth comparator, wherein a first input terminal of the fourth comparator is used to receive the third voltage signal and the first voltage signal, a second input terminal is used to receive a comparison signal corresponding to the fourth threshold, and an output terminal is used to output the wake-up signal.

[0017] In one embodiment of the first aspect of this application, the signal further includes one or more of the following: a second signal processing module, configured to process the second voltage signal and output the processed second voltage signal to the wake-up detection module, wherein the processing of the second voltage signal includes one or more of filtering and delay processing; or a third signal processing module, configured to process the third voltage signal and output the processed third voltage signal to the wake-up detection module, wherein the processing of the third voltage signal includes one or more of filtering and delay processing; or a fourth signal processing module, configured to process the first voltage signal and output the processed first voltage signal to the wake-up detection module, wherein the processing of the first voltage signal includes one or more of filtering and delay processing.

[0018] In one embodiment of the first aspect of this application, the wake-up detection module includes: a multi-input comparator, wherein multiple input terminals of the multi-input comparator are respectively used to receive the temperature signal, the first voltage signal, the second voltage signal, the third voltage signal, the comparison signal corresponding to the first threshold, the comparison signal corresponding to the second threshold, the comparison signal corresponding to the third threshold, and the comparison signal corresponding to the fourth threshold, and the output terminal of the multi-input comparator is used to output the wake-up signal.

[0019] A second aspect of this application provides a battery management system, including: a controller, and a detection circuit for a low-voltage battery as described in any of the first aspects of this application.

[0020] A third aspect of this application provides an electrical device, including: a low-voltage battery, and a battery management system as described in the second aspect of this application.

[0021] In summary, the low-voltage battery detection circuit, battery management system, and electrical equipment provided in this application can, when the BMS is in a dormant state, have the temperature detection module detect the temperature of at least one switch in the charging and discharging circuit of the low-voltage battery and output a temperature signal, and the current detection module detect the current of at least one switch in the charging and discharging circuit of the low-voltage battery and output a voltage signal. This allows the wake-up detection module to output a wake-up signal to the controller when the amplitude of the temperature signal meets the over-temperature amplitude condition and / or the voltage signal meets the over-current amplitude condition, thereby waking the controller to handle abnormalities. This more accurately and effectively detects abnormalities such as high-current discharge or long-term low-current discharge of the low-voltage battery, and wakes the controller to handle abnormalities more promptly. This effectively prevents safety hazards caused by the controller's inability to handle abnormalities in a timely manner while in a dormant state, thus ensuring the safe and stable operation of the low-voltage battery and the electrical equipment it is connected to. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram illustrating the application scenario of this application;

[0024] Figure 2 A schematic diagram of a BMS embodiment provided in this application;

[0025] Figure 3 A schematic diagram of the structure of an embodiment of the detection circuit for the low-voltage battery provided in this application;

[0026] Figure 4 A schematic diagram of the circuit structure of an embodiment of the detection circuit for the low-voltage battery provided in this application;

[0027] Figure 5 This is a schematic diagram of the structure of an embodiment of the RC filter circuit provided in this application;

[0028] Figure 6 This is a schematic diagram of the circuit structure of another embodiment of the detection circuit for the low-voltage battery provided in this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] Figure 1 This is a schematic diagram illustrating the application scenario of this application, such as... Figure 1 As shown, this application is used in electrical equipment such as electric vehicles, specifically, as... Figure 1 The electrical equipment shown is an electric vehicle as an example. The electric vehicle includes a low-voltage battery 1 and a BMS2. The low-voltage battery 1 can be used to supply power to the load in the electric vehicle, and the BMS2 can be used to control and manage the low-voltage battery 1.

[0032] In one embodiment, such as Figure 1 The low-voltage battery 1 shown includes multiple cells connected in series. The positive terminal Batt+ of the low-voltage battery 1 is connected to the positive output terminal PACK+, and the negative terminal Batt- of the low-voltage battery 1 is connected to the negative output terminal PACK-. The positive output terminal PACK+ and the negative output terminal PACK- can be used to connect a load, thereby enabling the low-voltage battery 1 to supply power to the load.

[0033] In one embodiment, such as Figure 1 The BMS2 shown specifically includes: a controller 20, a charging switch S1, and a discharging switch S2. The charging switch S1 and discharging switch S2 are configured in the charging and discharging circuit of the voltage battery 1. Figure 1In the example shown, the discharge circuit of the low-voltage battery 1 includes: the positive terminal Batt+ of the low-voltage battery 1, the positive output terminal PACK+, the negative output terminal PACK-, and the negative terminal Batt- of the low-voltage battery 1. The charging circuit of the low-voltage battery 1 includes: the negative terminal Batt- of the low-voltage battery 1, the negative output terminal PACK-, the positive output terminal PACK+, and the positive terminal Batt+ of the low-voltage battery 1.

[0034] Specifically, in Figure 1 In the example shown, the first terminal of the charging switch S1 is connected to the positive terminal Batt+ of the low-voltage battery 1, the second terminal of the charging switch S1 is connected to the first terminal of the discharging switch S2, and the second terminal of the discharging switch S2 is connected to the positive output terminal PACK+.

[0035] In one embodiment, both the charging switch S1 and the discharging switch S2 are MOS controllers. The control terminals of the charging switch S1 and the discharging switch S2 are respectively connected to the controller 20. The controller 20 can be used to control the charging switch S1 to be turned on and off, and to control the discharging switch S2 to be turned on and off.

[0036] In the specific implementation process, the controller 20 can monitor the voltage, current, temperature and other information of the low-voltage battery 1 and its charging and discharging circuit. When the low-voltage battery 1 experiences abnormalities such as overvoltage, overcurrent, or overtemperature, the controller 20 will execute corresponding protection measures according to the current abnormal state. For example, the controller 20 can control one or more of the charging switch S1 and the discharging switch S2 to disconnect, so as to deal with the abnormalities of the low-voltage battery 1 in a timely manner and ensure the safe and stable operation of the low-voltage battery 1 and the entire electrical equipment it is connected to.

[0037] However, in Figure 1 In the electrical equipment shown, under certain circumstances, BMS2 will switch to sleep mode to save power, while the low-voltage battery 1 remains in an operational state. However, when BMS2 is in sleep mode, if an abnormality occurs in the low-voltage battery 1 and its charging / discharging circuit, the controller 20 of BMS2 will be unable to take timely protective measures to handle the abnormality, posing a serious safety hazard to the low-voltage battery 1 and the electrical equipment it is connected to.

[0038] Especially when BMS2 is in a dormant state, and the low-voltage battery 1 is over-discharged and experiences a large current discharge, such as a short circuit or abnormal load connection, and there is a situation where a small current is supplied for a long time in the charging and discharging circuit where the low-voltage battery 1 is located, the charging switch S1, discharging switch S2 and other MOSFETs in the charging and discharging circuit may be damaged due to overheating due to continuous operation. These abnormalities will seriously affect the safety of the electrical equipment.

[0039] Therefore, how to detect the low-voltage battery 1 even when the BMS2 is in a dormant state, so as to wake up the controller 20 of the BMS2 in time when the low-voltage battery 1 exhibits the above-mentioned abnormalities, and enable the controller 20 to handle these abnormalities, is a technical problem that needs to be solved in this field.

[0040] Based on this, this application provides a detection circuit for a low-voltage battery, a battery management system, and an electrical device. When the BMS2 is in a dormant state, it detects the temperature and current of at least one switch on the charging and discharging circuit where the low-voltage battery 1 is located, and wakes up the controller 20 in time to handle the abnormality when an abnormality is detected, thereby eliminating the safety hazards of the low-voltage battery 1 and the electrical device it is located in.

[0041] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0042] Figure 2 A schematic diagram of a BMS embodiment provided in this application is shown below. Figure 2 The BMS2 shown can be applied to, for example Figure 1 Among the electrical equipment shown. Specifically, such as Figure 2 The BMS2 shown includes a controller 20 and a low-voltage battery detection circuit 21. The low-voltage battery detection circuit 21 is connected to both the low-voltage battery 1 and the low-voltage battery detection circuit 21. The low-voltage battery detection circuit 21 can detect the low-voltage battery 1 when the BMS2 is in sleep mode, and send a wake-up signal to the controller 20 if over-temperature or over-current occurs in the charging / discharging circuit containing the low-voltage battery 1. When the controller 20 receives the wake-up signal, it switches from sleep mode to normal operation mode and can promptly handle abnormalities in the low-voltage battery 1 by controlling one or more of the charging switch S1 and discharging switch S2 to disconnect.

[0043] More specifically, Figure 3 A schematic diagram of an embodiment of the detection circuit for a low-voltage battery provided in this application is shown. Figure 2 This is a specific implementation of the low-voltage battery detection circuit 21 provided in the example. For instance... Figure 2 The detection circuit 21 of the low-voltage battery shown includes: a temperature detection module 211, a current detection module 210, and a wake-up detection module 212.

[0044] The temperature detection module 211 can be used to detect the temperature of at least one switch in the charging and discharging circuit of the low-voltage battery 1, and output a temperature signal to the wake-up detection module 212 according to the temperature of the at least one switch.

[0045] The current detection module 210 can be used to detect the voltage of at least one switch in the charging and discharging circuit of the low-voltage battery 1 and output a voltage signal to the wake-up detection module 212. Specifically, the current detection module 210 indirectly detects the current flowing through at least one switch by the voltage generated on both sides of the at least one switch by the current flowing through the at least one switch.

[0046] In one embodiment, combined with Figure 1 In the scenario shown, at least one switch includes one or more of a charging switch S1 and a discharging switch S2 on the charging and discharging circuit of the low-voltage battery 1.

[0047] Specifically, the amplitude of the temperature signal output by the temperature detection module 211 is related to the detected temperature. For example, the higher the temperature of at least one switch detected by the temperature detection module 211, the lower the amplitude of the temperature signal; the lower the temperature of at least one switch detected by the temperature detection module 211, the higher the amplitude of the temperature signal.

[0048] In other words, the amplitude of the temperature signal output by the temperature detection module 211 can be used to characterize the temperature of at least one switch, and the temperature of these at least one switch is related to the current flowing through them. Specifically, the larger the current value flowing through at least one switch and the longer the duration, the higher the temperature of the at least one switch; conversely, the shorter the effective current value flowing through at least one switch and the shorter the duration, the lower the temperature of the at least one switch. Therefore, the amplitude of the temperature signal output by the temperature detection module 211 is equivalent to the current flowing through at least one switch.

[0049] Furthermore, the amplitude of the voltage signal output by the current detection module 210 is related to the current flowing through at least one switch in the charging / discharging circuit. For example, the larger the current flowing through at least one switch in the charging / discharging circuit, the higher the amplitude of the voltage signal; the smaller the current flowing through at least one switch in the charging / discharging circuit, the lower the amplitude of the voltage signal. Therefore, the amplitude of the voltage signal output by the current detection module 210 can be used to characterize the current flowing through at least one switch in the charging / discharging circuit.

[0050] The wake-up detection module 212 is used to output a wake-up signal to the controller 20 of BMS2 when the amplitude of the received temperature signal meets the over-temperature amplitude condition.

[0051] Alternatively, the wake-up detection module 212 is used to output a wake-up signal to the controller 20 of the BMS2 when the amplitude of the received voltage signal meets the overcurrent amplitude condition.

[0052] Alternatively, the wake-up detection module 212 is used to output a wake-up signal to the controller 20 of the BMS2 when the amplitude of the received temperature signal meets the over-temperature amplitude condition and the amplitude of the received voltage signal meets the over-current amplitude condition.

[0053] The wake-up signal is used to wake up the controller 20 from its sleep state. For example, when the BMS2 is in sleep state and the controller 20 receives the wake-up signal, the controller 20 switches from sleep state to normal operating state. After switching to normal operating state, the controller 20 can promptly handle any abnormalities in the low-voltage battery 1 by controlling one or more of the charging switch S1 and discharging switch S2 to disconnect.

[0054] For example, in the first scenario, when the low-voltage battery 1 experiences a large current discharge due to over-discharge, and the amplitude of the voltage signal output by the current detection module 210 meets the overcurrent amplitude condition caused by overcurrent, the wake-up detection module 212 outputs a wake-up signal to the controller 20.

[0055] In the second scenario, when there is a small current supplying power for a long time in the charging and discharging circuit where the low-voltage battery 1 is located, at least one switch in the charging and discharging circuit will have a rising temperature due to continuous operation. If the amplitude of the temperature signal output by the temperature detection module 211 meets the over-temperature amplitude condition, the wake-up detection module 212 will output a wake-up signal to the controller 20, thereby ensuring that at least one switch will not be damaged by over-temperature.

[0056] In summary, the low-voltage battery detection circuit 21 provided in this embodiment can detect the temperature of at least one switch in the charging and discharging circuit of the low-voltage battery 1 by the temperature detection module 211 and output a temperature signal, and detect the current of at least one switch in the charging and discharging circuit of the low-voltage battery 1 and output a voltage signal when the BMS2 is in a dormant state. When the amplitude of the temperature signal meets the over-temperature amplitude condition and / or the voltage signal meets the over-current amplitude condition, the wake-up detection module 212 outputs a wake-up signal to the controller 20 to wake up the controller 20 to handle the abnormality. This allows for more accurate and effective detection of abnormalities such as large current discharge or long-term small current discharge of the low-voltage battery 1, and more timely wake-up of the controller 20 to handle the abnormality. This effectively prevents the safety hazards caused by the controller 20 being unable to handle abnormalities in a timely manner when it is in a dormant state, thereby ensuring the safe and stable operation of the low-voltage battery 1 and the electrical equipment it is connected to.

[0057] Furthermore, it should be noted that the low-voltage battery detection circuit 21 provided in this embodiment can be used to send a wake-up signal to the controller 20 to wake up the controller 20 when the BMS2 is in a sleep state. When the BMS2 is not in a sleep state, the low-voltage battery detection circuit 21 can still send a wake-up signal to the controller 20. In this case, the controller 20 can promptly handle any abnormalities in the low-voltage battery 1 by controlling one or more of the charging switch S1 and discharging switch S2 to disconnect, based on the received wake-up signal. In other words, when the BMS2 is not in a sleep state, the low-voltage battery detection circuit 21 can be used to detect whether the low-voltage battery 1 is malfunctioning.

[0058] In one embodiment, the temperature detection module 211 can be used to detect the temperature of the charging switch S1 on the charging and discharging circuit of the low-voltage battery 1, and output a temperature signal according to the temperature of the charging switch S1.

[0059] In one embodiment, the temperature detection module 211 can be used to detect the temperature of the discharge switch S2 on the charging and discharging circuit of the low-voltage battery 1, and output a temperature signal according to the temperature of the discharge switch S2.

[0060] In one embodiment, the temperature detection module 211 can be used to detect the temperature of the charging switch S1 and the discharging switch S2 on the charging and discharging circuit of the low-voltage battery 1, and simultaneously output a temperature signal based on the temperature of the charging switch S1 and the discharging switch S2.

[0061] For example, Figure 4 A schematic diagram of the circuit structure of an embodiment of the detection circuit for a low-voltage battery provided in this application is shown. Figure 3 The provided low-voltage battery detection circuit is a specific circuit implementation. Specifically, such as... Figure 3 In the embodiment shown, the temperature detection module 211 includes a negative temperature coefficient (NTC) temperature sensor, wherein the NTC temperature sensor is disposed on the charging and discharging circuit of the low-voltage battery 1, between the charging switch S1 and the discharging switch S2, and is respectively attached to the charging switch S1 and the discharging switch S2.

[0062] Specifically, the NTC temperature sensor includes a thermistor. When the detected temperature rises, the resistance of the thermistor decreases, causing the voltage V across the thermistor to change. TMOS The amplitude decreases, causing the voltage V to... TMOS It is negatively correlated with temperature; therefore, the voltage V across the thermistor in the NTC temperature sensor can be used to measure this voltage. TMOS The temperature signal is output to the wake-up detection module 212.

[0063] Therefore, the NTC temperature sensor provided in this embodiment can be used to detect the temperature of charging switch S1 and discharging switch S2. Based on this, when the temperature of charging switch S1 rises, the amplitude of the temperature signal output by temperature detection module 211 according to the temperature of charging switch S1 meets the overcurrent amplitude condition; and when the temperature of discharging switch S2 rises, the amplitude of the temperature signal output by temperature detection module 211 according to the temperature of discharging switch S2 also meets the overcurrent amplitude condition; when the temperatures of charging switch S1 and discharging switch S2 rise simultaneously, the amplitude of the temperature signal output by temperature detection module 211 also meets the overcurrent amplitude condition.

[0064] More specifically, the amplitude of the temperature signal output by the NTC temperature sensor is negatively correlated with the detected temperature. Therefore, for the wake-up detection module 21, when the amplitude of the received temperature signal is less than or equal to the first threshold V... Tlimit If the overcurrent amplitude condition is met, and it is determined that the temperature of at least one switch detected by the NTC temperature sensor is high, then the wake-up detection module 21 outputs a wake-up signal to the controller 20.

[0065] In one embodiment, the wake-up detection module 212 includes a first comparator. A first input terminal of the first comparator is used to receive a temperature signal input from the temperature detection module 211, and a second input terminal of the first comparator is used to receive a first threshold V. Tlimit The corresponding comparison signal, the first comparator can be used to compare the temperature signal with the first threshold V. Tlimit The corresponding comparison signals are compared using a self-judgment method, thus determining whether the amplitude of the temperature signal is less than or equal to the first threshold V. Tlimit In this case, the output of the first comparator outputs a wake-up signal to the controller 20. In this embodiment, the hardware comparison using the first comparator enables the determination of whether the amplitude of the temperature signal is less than or equal to a first threshold V. Tlimit This allows for a faster response to various situations, enabling the controller 20 to be activated more promptly to take appropriate measures and thus more effectively resolve safety hazards.

[0066] Therefore, from Figure 4 As can be seen from the circuit structure diagram of the low-voltage battery detection circuit 21 shown, the detection circuit 21 provided in this embodiment is implemented by basic circuit devices such as temperature sensors and hardware comparators, which makes the detection circuit 21 provided in this application have the beneficial effects of simple circuit structure and low complexity, and can also reduce the implementation cost of the detection circuit 21 and its BMS2.

[0067] Furthermore, the detection 21 provided in this embodiment also includes a first signal processing module 221, such as... Figure 4As shown, the first signal processing module 221 is disposed between the temperature detection module 211 and the wake-up detection module 212. The first signal processing module 221 can process the temperature signal output by the temperature detection module 211 and output the processed temperature signal to the wake-up detection module 212.

[0068] In one embodiment, the processing of the temperature signal by the first signal processing module 221 includes one or more of filtering and delay processing.

[0069] In one embodiment, the first signal processing module 221 includes an RC filter circuit, which can be used to filter the temperature signal to reduce noise interference in the temperature signal and improve the effectiveness and sensitivity of the detection circuit 21. Simultaneously, the capacitor in the RC filter circuit can also delay the temperature signal, thereby preventing the transient high current of the temperature signal from impacting the downstream wake-up detection module 212 and controller 20, effectively improving the reliability and stability of the detection circuit 21 and its associated BMS2.

[0070] For example, Figure 5 This is a schematic diagram of an embodiment of the RC filter circuit provided in this application, as shown below. Figure 5 The RC filter circuit shown includes capacitors Cv1, Cv2, Cv3, and Cv4, and resistor Rv1. The RC filter circuit can be used to obtain the input voltage signal Vin from its input terminal, perform filtering and delay processing, and then output a voltage signal Vout from its output terminal. Specifically, based on the high impedance of the capacitor for low-frequency signals and the low impedance for high-frequency signals, low-frequency signals can be transmitted relatively easily through resistor Rv1, while high-frequency signals are isolated by the capacitor. Furthermore, when the voltage signal Vin is input to the input terminal, the voltage signal Vin charges the capacitor; the longer the charging time, the longer the delay of the output voltage signal Vout.

[0071] In one embodiment, the first signal processing module 221 uses, for example... Figure 5 In the RC filter circuit shown, the voltage signal Vin obtained by the input terminal of the first signal processing module 211 is a temperature signal, and the voltage signal Vout output by the output terminal of the first signal processing module 211 is the processed temperature signal.

[0072] In a first specific implementation, the current detection module 210 provided in this application includes: a first voltage acquisition unit, used to acquire the first voltage V at point X across the terminals of the adjacent charging switch S1 and discharging switch S2 in the charging and discharging circuit. s1 and the second voltage V at point Z s2 and the first voltage V s1 As the first voltage signal, the second voltage V s2As the second voltage signal, the first voltage signal V is output to the wake-up detection module 212. s1 Second voltage signal V s2 .

[0073] exist Figure 4 In the example shown, the first voltage acquisition unit includes a connection line between point X on the charging and discharging circuit of the low-voltage battery 1 and the wake-up detection module 212, and a connection line between point Z and the wake-up detection module 212.

[0074] Then, when the wake-up detection module 212 receives the first voltage signal V s1 Second voltage signal V s2 Then, based on the first voltage signal V s1 With the second voltage signal V s2 The difference in amplitude, and the second threshold V Tlimit1 Compare, and in the first voltage signal V s1 With the second voltage signal V s2 The difference in amplitude is greater than or equal to the second threshold V Tlimit1 In the event of a certain condition, the wake-up detection module 212 outputs a wake-up signal to the controller 20.

[0075] In one embodiment, the wake-up detection module 212 specifically includes a second comparator, the first input terminal of which is used to receive a first voltage signal V. s1 With the second voltage signal V s2 The second input terminal is used to receive the second threshold V. Tlimit1 The corresponding comparison signal, then the second comparator can be used to compare the first voltage signal V. s1 With the second voltage signal V s2 The difference in amplitude, and the second threshold V Tlimit1 The corresponding comparison signals are compared, thereby determining the first voltage signal V. s1 With the second voltage signal V s2 The difference in amplitude is greater than or equal to the second threshold V Tlimit1 In this case, the output of the second comparator outputs a wake-up signal to the controller 20.

[0076] In the second specific implementation, the current detection module 210 provided in this application includes: a second voltage acquisition unit, used to acquire the third voltage V at point Y across the discharge switch S2 in the charging and discharging circuit. D and the second voltage V at point Z s2 and the third voltage V D As the third voltage signal, the second voltage V s2 As the second voltage signal, a third voltage signal V is output to the wake-up detection module 212. D Second voltage signal V s2 .

[0077] exist Figure 4 In the example shown, the second voltage acquisition unit includes a connection line between point Z on the charging and discharging circuit of the low-voltage battery 1 and the wake-up detection module 212, and a connection line between point Y and the wake-up detection module 212.

[0078] Then, when the wake-up detection module 212 receives the third voltage signal V D Second voltage signal V s2 Then, based on the third voltage signal V D With the second voltage signal V s2 The difference in amplitude, and the third threshold V Tlimit2 Compare, and in the third voltage signal V D With the second voltage signal V s2 The difference in amplitude is greater than or equal to the third threshold V Tlimit2 In the event of a certain condition, the wake-up detection module 212 outputs a wake-up signal to the controller 20.

[0079] In one embodiment, the wake-up detection module 212 specifically includes a third comparator, the first input of which is used to receive a third voltage signal V. D With the second voltage signal V s2 The second input terminal is used to receive the third threshold V. Tlimit2 The corresponding comparison signal, the third comparator can be used to compare the third voltage signal V. D With the second voltage signal V s2 The difference in amplitude, and the third threshold V Tlimit2 The corresponding comparison signals are compared, thereby determining the voltage V at the third voltage. D With the second voltage signal V s2 The difference in amplitude is greater than or equal to the third threshold V Tlimit2 In this case, the output of the third comparator outputs a wake-up signal to the controller 20.

[0080] In the third specific implementation, the current detection module 210 provided in this application includes: a third voltage acquisition unit, used to acquire the first voltage V at point X across the charging switch S1 in the charging and discharging circuit. s1 and the third voltage V at point Y D and the first voltage V s1 As the first voltage signal, the third voltage V D As the third voltage signal, the first voltage signal V is output to the wake-up detection module 212. s1 and the third voltage signal V D .

[0081] exist Figure 4In the example shown, the third voltage acquisition unit includes a connection line between point X on the charging and discharging circuit of the low-voltage battery 1 and the wake-up detection module 212, and a connection line between point Z and the wake-up detection module 212.

[0082] Then, when the wake-up detection module 212 receives the first voltage signal V s1 and the third voltage signal V D Then, based on the first voltage signal V s1 With the third voltage signal V D The difference in amplitude, and the fourth threshold V Tlimit3 Compare, and in the first voltage signal V s1 With the third voltage signal V D The difference in amplitude is greater than or equal to the fourth threshold V Tlimit3 In the event of a certain condition, the wake-up detection module 212 outputs a wake-up signal to the controller 20.

[0083] In one embodiment, the wake-up detection module 212 specifically includes a fourth comparator, the first input of which is used to receive a first voltage signal V. s1 With the third voltage signal V D The second input terminal is used to receive the fourth threshold V. Tlimit3 The corresponding comparison signal, then the third comparator can be used to compare the first voltage signal V. s1 With the third voltage signal V D The difference in amplitude, and the fourth threshold V Tlimit3 The corresponding comparison signals are compared, thereby determining the first voltage V. s1 Signal and third voltage signal V D The difference in amplitude is greater than or equal to the fourth threshold V Tlimit3 In this case, the output of the fourth comparator outputs a wake-up signal to the controller 20.

[0084] In one embodiment, such as Figure 4 The detection circuit 21 shown may also include one or more of the following: a second signal processing module 222, a third signal processing module 223 or a fourth signal processing module 224.

[0085] One end of the second signal processor module 222 is used to acquire the second voltage signal V at point Z. s2 The second signal processor module 222 is used to process the second voltage signal V. s2 The signal is processed and the processed second voltage signal V is output to the wake-up detection module 212. s2 Among them, the second voltage signal V s2 The processing includes one or more of filtering and delay processing. In one embodiment, the second signal processing module 222 includes, for example, filtering and delay processing. Figure 5The RC filter circuit shown.

[0086] One end of the third signal processing module 223 is used to acquire the third voltage signal V at point Y. D The third signal processor module 223 is used to process the third voltage signal V. D The signal is processed and the processed third voltage signal V is output to the wake-up detection module 212. D Among them, the third voltage signal V D The processing includes one or more of filtering and delay processing. In one embodiment, the third signal processing module 223 includes, for example, filtering and delay processing. Figure 5 The RC filter circuit shown.

[0087] One end of the fourth signal processing module 224 is used to acquire the first voltage signal V at point X. s1 The fourth signal processing module 224 is used to process the first voltage signal V s1 The signal is processed and the processed first voltage signal V is output to the wake-up detection module 212. s1 Among them, the first voltage signal V s1 The processing includes one or more of filtering and delay processing. In one embodiment, the fourth signal processing module 224 includes, for example, filtering and delay processing. Figure 5 The RC filter circuit shown.

[0088] It is understood that the detection circuit provided in this application offers multiple detection strategies for temperature and voltage, and these detection strategies can be used individually or in combination according to actual needs to achieve more accurate detection.

[0089] For the wake-up detection module 212, at least one comparator can be set according to the received signal or voltage.

[0090] In one embodiment, when the wake-up detection module 212 needs to make judgments based on multiple signals, the wake-up detection module 212 may include a multi-input comparator. For example, the multiple input terminals of the multi-input comparator are respectively used to receive a temperature signal, a first voltage signal, a second voltage signal, a third voltage signal, a comparison signal corresponding to a first threshold, a comparison signal corresponding to a second threshold, a comparison signal corresponding to a third threshold, and a comparison signal corresponding to a fourth threshold. When all conditions are met, the output terminal of the multi-input comparator outputs a wake-up signal. This embodiment reduces the complexity of the circuit structure by using a multi-input comparator, which is beneficial for reducing costs and promoting the widespread application of the detection circuit.

[0091] More specifically, based on Figure 4 The present application also provides a method for applying the detection circuit 21 shown in the figure, which includes at least the following steps:

[0092] Step S01: BMS2 enters sleep mode, and low-voltage battery 1 supplies power to the outside normally through the charging and discharging circuit.

[0093] Step S02: Obtain the first threshold V required by the wake-up detection module 212 Tlimit Second threshold V Tlimit1 Third threshold V Tlimi2 and the fourth threshold V Tlimi3 .

[0094] Step S03: Temperature detection module 211 detects the temperature between charging switch S1 and discharging switch S2, and outputs a temperature signal to wake-up detection module 212.

[0095] Step S04: The wake-up detection module 212 compares the amplitude of the temperature signal with the comparison signal corresponding to the first threshold. If the amplitude is less than or equal to the first threshold, then step S11 is executed; otherwise, step S05 is executed.

[0096] Step S05: The current detection module 210 acquires the first voltage signal V at point X. s1 and the second voltage signal V at point Z s2 And the third voltage signal V at point Y D And output to the wake-up detection module 212.

[0097] Step S06: Wake up the detection module 212 to calculate the first voltage signal V s1 With the second voltage signal V s2 The difference in amplitude, the third voltage signal V D With the second voltage signal V s2 The difference in amplitude, the first voltage signal V s1 With the third voltage signal V D The difference in amplitude.

[0098] Step S07: Wake up the detection module 212 and send the first voltage signal V s1 With the second voltage signal V s2 The difference between the two thresholds, and the second threshold V. Tlimit1 The corresponding comparison signals are compared, and the first voltage signal V is used for comparison. s1 With the second voltage signal V s2 The difference in amplitude is greater than or equal to the second threshold V Tlimit1 If the condition is met, proceed to step S11; otherwise, proceed to step S08.

[0099] Step S08: Wake up the detection module 212 and send the third voltage signal V D With the second voltage signal V s2 The difference between the third threshold V and the third threshold V Tlimit2The corresponding comparison signals are compared, and the third voltage signal V is used for comparison. D With the second voltage signal V s2 The difference in amplitude is greater than or equal to the third threshold V Tlimit2 If the condition is met, proceed to step S11; otherwise, proceed to step S09.

[0100] Step S09: Wake up the detection module 212 and send the first voltage signal V s1 With the third voltage signal V D The difference between the fourth threshold V and the fourth threshold V Tlimit3 The corresponding comparison signals are compared, and the first voltage signal V is used for comparison. s1 With the third voltage signal V D The difference in amplitude is greater than or equal to the fourth threshold V Tlimit3 If the condition is met, proceed to step S11; otherwise, proceed to step S10.

[0101] Step S10: Determine that the low-voltage battery 1 has not experienced a safety fault while the BMS2 is in a sleep state, and the low-voltage battery 1 continues to supply power.

[0102] Step S11: The wake-up detection module 212 outputs a wake-up signal to the controller 20, triggering the controller 20 to wake up.

[0103] Step S12: The controller 20 detects the relevant parameters of the low-voltage battery 1, determines the fault state of the low-voltage battery 1, and executes corresponding protection measures, such as disconnecting the charging switch, to ensure the safe operation of the low-voltage battery 1 and the electrical equipment it is connected to.

[0104] also, Figure 6 This is a schematic diagram of the circuit structure of another embodiment of the detection circuit for a low-voltage battery provided in this application. Based on the same technical concept as the aforementioned embodiments of this application, the detection circuit may also include a shunt detection module for the shunt 3. The shunt is located on the charging and discharging circuit where the low-voltage battery 1 is located. The shunt detection module is used to detect the current of the shunt 3 and output a current signal to the wake-up detection module 212. When the amplitude of the current signal meets the first abnormal amplitude condition, the wake-up detection module 212 outputs a wake-up signal to the controller 20. The first abnormal amplitude condition includes the amplitude of the current signal being greater than or equal to a current threshold.

[0105] In one embodiment, the detection circuit may further include a fuse voltage detection module, which can be used to detect the voltage across the fuse located next to the charging switch S1 and / or discharging switch S2 in the charging / discharging circuit where the low-voltage battery 1 is located, and output a fuse voltage signal to the wake-up detection module 212, wherein the amplitude of the fuse voltage signal is related to the current flowing through the fuse. The wake-up detection module 212 may output a wake-up signal to the controller 20 if the amplitude of the fuse voltage meets a second abnormal amplitude condition, the second abnormal amplitude condition including an amplitude greater than or equal to a voltage threshold.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A detection circuit for a low-voltage battery, characterized in that, include: A temperature detection module is used to detect the temperature of at least one switch in the charging and discharging circuit of the low-voltage battery and output a temperature signal to the wake-up detection module. The amplitude of the temperature signal is related to the temperature of the at least one switch. A current detection module is used to detect the voltage of the at least one switch and output a voltage signal to the wake-up detection module, the amplitude of which is related to the current in the charging and discharging circuit. The wake-up detection module is used to output a wake-up signal to the controller of the battery management system of the low-voltage battery when the amplitude of the temperature signal meets the over-temperature amplitude condition and / or the amplitude of the voltage signal meets the over-current amplitude condition. The wake-up signal is used to wake up the controller in a dormant state.

2. The circuit according to claim 1, characterized in that, The temperature detection module is disposed between the charging switch and the discharging switch in the charging and discharging circuit, and is respectively attached to the charging switch and the discharging switch; The temperature detection module is used to detect the temperature of the charging switch and the temperature of the discharging switch.

3. The circuit according to claim 2, characterized in that, The temperature detection module includes a negative temperature coefficient (NTC) temperature sensor, wherein the amplitude of the temperature signal output by the NTC temperature sensor is negatively correlated with the temperature of the at least one switch.

4. The circuit according to claim 3, characterized in that, The over-temperature amplitude condition includes: the amplitude of the temperature signal is less than or equal to a first threshold.

5. The circuit according to claim 4, characterized in that, The wake-up detection module includes: a first comparator, wherein a first input terminal of the first comparator is used to receive the temperature signal, a second input terminal is used to receive a comparison signal corresponding to the first threshold, and an output terminal is used to output the wake-up signal.

6. The circuit according to claim 5, characterized in that, Also includes: A first signal processing module, wherein the temperature detection module is connected to the wake-up detection module through the first signal processing module; The first signal processing module is used to acquire the temperature signal, process the temperature signal, and output the processed temperature signal to the wake-up detection module; wherein the processing of the temperature signal includes one or more of filtering processing and delay processing.

7. The circuit according to any one of claims 1-6, characterized in that, The current detection module includes: The first voltage acquisition unit is used to acquire the first voltage and the second voltage across the charging switch and the discharging switch that are adjacently arranged on the charging and discharging circuit, and output the first voltage signal and the second voltage signal to the wake-up detection module. The overcurrent amplitude condition includes: the difference between the amplitudes of the first voltage signal and the second voltage signal is greater than or equal to a second threshold.

8. The circuit according to claim 7, characterized in that, The wake-up detection module includes: a second comparator, wherein the first input terminal of the second comparator is used to receive the first voltage signal and the second voltage signal, the second input terminal is used to receive the comparison signal corresponding to the second threshold, and the output terminal is used to output the wake-up signal.

9. The circuit according to claim 7, characterized in that, The current detection module includes: The second voltage acquisition unit is used to acquire the third voltage and the second voltage across the discharge switch in the charging and discharging circuit, and output the third voltage signal and the second voltage signal to the wake-up detection module. The overcurrent amplitude condition includes: the difference between the amplitudes of the third voltage signal and the second voltage signal is greater than or equal to a third threshold.

10. The circuit according to claim 9, characterized in that, The wake-up detection module includes a third comparator, wherein the first input terminal of the third comparator is used to receive the third voltage signal and the second voltage signal, the second input terminal is used to receive the comparison signal corresponding to the third threshold, and the output terminal is used to output the wake-up signal.

11. The circuit according to claim 9, characterized in that, The current detection module includes: The third voltage acquisition unit is used to acquire the third voltage and the first voltage at both ends of the charging switch on the charging and discharging circuit, and output the third voltage signal and the first voltage signal to the wake-up detection module. The overcurrent amplitude condition includes: the difference between the amplitudes of the first voltage signal and the third voltage signal is greater than or equal to a fourth threshold.

12. The circuit according to claim 11, characterized in that, The wake-up detection module includes a fourth comparator, wherein the first input terminal of the fourth comparator is used to receive the third voltage signal and the first voltage signal, the second input terminal is used to receive the comparison signal corresponding to the fourth threshold, and the output terminal is used to output the wake-up signal.

13. The circuit according to any one of claims 8-12, characterized in that, It also includes one or more of the following: The second signal processing module is used to process the second voltage signal and output the processed second voltage signal to the wake-up detection module. The processing of the second voltage signal includes one or more of filtering and delay processing. Alternatively, a third signal processing module is used to process the third voltage signal and output the processed third voltage signal to the wake-up detection module. The processing of the third voltage signal includes one or more of filtering and delay processing. Alternatively, a fourth signal processing module is used to process the first voltage signal and output the processed first voltage signal to the wake-up detection module. The processing of the first voltage signal includes one or more of filtering and delay processing.

14. The circuit according to claim 1, characterized in that, The wake-up detection module includes a multi-input comparator, wherein multiple input terminals of the multi-input comparator are respectively used to receive the temperature signal, the first voltage signal, the second voltage signal, the third voltage signal, the comparison signal corresponding to the first threshold, the comparison signal corresponding to the second threshold, the comparison signal corresponding to the third threshold, and the comparison signal corresponding to the fourth threshold, and the output terminal of the multi-input comparator is used to output the wake-up signal.

15. The circuit according to claim 1, characterized in that, Also includes: The shunt detection module is used to detect the current of the shunt in the charging and discharging circuit of the low-voltage battery and output a current signal to the wake-up detection module. The amplitude of the current signal is related to the current of the shunt. The wake-up detection module is further configured to output a wake-up signal to the controller of the battery management system of the low-voltage battery when the amplitude of the current signal meets the first abnormal amplitude condition.

16. The circuit according to claim 1, characterized in that, Also includes: The fuse voltage detection module is used to detect the voltage of a fuse installed next to at least one switch in the charging and discharging circuit of the low-voltage battery, and output a fuse voltage signal to the wake-up detection module. The amplitude of the fuse voltage signal is related to the current flowing through the fuse. The wake-up detection module is further configured to output a wake-up signal to the controller of the battery management system of the low-voltage battery when the amplitude of the fuse voltage signal meets the second abnormal amplitude condition.

17. A battery management system, characterized in that, include: The controller, and the detection circuit for the low-voltage battery as described in any one of claims 1-16.

18. An electrical appliance, characterized in that, include: A low-voltage battery, and a battery management system as described in claim 17.

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