Fault detection of temperature sensor set

Abstract

The present disclosure describes a system and method for performing fault detection on a temperature sensor set (120). The temperature sensor group (120) includes a plurality of temperature sensors (NTC1, NTC2, NTC3) that provide a multi-channel sensing voltage at a plurality of pins (P1, P2, P3) of the conversion circuit (130). The bias circuit (211) is controlled by the test controller (212) to selectively pull up and / or pull down the voltage on the plurality of pins (P1, P2, P3) to obtain a plurality of test voltages. The test controller (212) determines a failure of the temperature sensor group (120) by comparing the sensed voltage and the test voltage. The fault detection system (210) can measure half of the plurality of pins (P1, P2, P3) at a time, so that a test program can be executed in real time under road conditions. Further, the fault detection system (210) is capable of identifying an open-circuit fault and a short-circuit fault in each channel of the temperature sensor group (120), and a short-circuit fault between adjacent ones of the plurality of pins (P1, P2, P3) of the conversion circuit (130).

Description

Technical Field

[0001] The present disclosure relates generally to electronic circuits and, more particularly, to fault detection of temperature sensor groups. Background Art

[0002] A temperature sensor group consists of multiple temperature sensors deployed within a system or device to monitor temperature changes at multiple locations. In the battery power system of an electric vehicle (EV), multiple battery cells within a battery pack are interconnected to provide sufficient power to drive the EV. A temperature sensor group is integrated into the battery power system to monitor the temperature of the various battery cells within the battery pack to ensure safe and efficient operation of the battery system.

[0003] Leakage current within battery packs is a significant concern because it can lead to various adverse effects, including reduced battery efficiency, accelerated aging, and potential safety hazards. Furthermore, leakage current can cause localized heating within the battery pack, exacerbating thermal management challenges and increasing the risk of thermal runaway events. An effective way to determine the presence of leakage current is to monitor the temperature near the battery cells.

[0004] By monitoring the temperature near the battery cells, any abnormal temperature rise can be identified, which may indicate leakage current. This can be achieved through various temperature sensing technologies, such as thermocouples, infrared sensors, or thermal imaging cameras. Once an anomaly is identified, appropriate measures can be taken to mitigate the problem, such as isolating or replacing the faulty battery cell. Promptly monitoring the temperature near the battery cells allows for timely intervention to prevent potential damage or safety hazards.

[0005] However, a temperature sensor in a temperature sensor assembly can become damaged due to a short circuit or open circuit, resulting in an incorrect temperature reading. Electric vehicle power battery systems include numerous battery cells and temperature sensors. Even a single temperature sensor failure can cause the electric vehicle to malfunction and fail to operate normally.

[0006] Conventional fault detection systems and methods for temperature sensor groups in battery power systems involve testing multiple temperature sensors individually. These methods require isolating the temperature sensor under test from the other temperature sensors, which is unsuitable for road conditions because the testing procedure is too time-consuming and affects the normal operation of the electric vehicle.

[0007] Therefore, a need exists for a system and method that can overcome the shortcomings of temperature sensor group fault detection. Summary of the Invention

[0008] According to one aspect of the present disclosure, a fault detection system for a temperature sensor group is provided. The temperature sensor group includes multiple temperature sensors configured to provide multi-channel sensing voltages at multiple pins. The fault detection system includes a bias circuit and a test controller coupled to the bias circuit and configured to control the bias circuit to selectively pull down and / or pull up the voltages at the multiple pins to obtain multiple test voltages. The test controller determines a fault in the temperature sensor group by comparing the sensing voltages with the test voltages.

[0009] According to another aspect of the present disclosure, a multi-channel temperature sensing circuit in a battery power system is provided, comprising: a temperature sensor group having multiple channels to provide a multi-channel sensing voltage, each of the multiple channels having a temperature sensor; a conversion circuit coupled to the temperature sensor group to convert an analog value of the sensing voltage into a digital value; and a fault detection system as described above, for detecting a fault of the temperature sensor group in a test procedure, wherein the temperature sensor group detects the temperature near a battery cell of the battery power system.

[0010] According to another aspect of the present disclosure, a fault detection method for a temperature sensor group is provided. The temperature sensor group includes multiple temperature sensors configured to provide multi-channel sensing voltages at multiple pins. The fault detection method includes measuring the sensing voltages at the multiple pins; measuring multiple test voltages at the multiple pins while the multiple pins are selectively pulled down to a first preset voltage and / or pulled up to a second preset voltage; and determining a fault in the temperature sensor group by comparing the multiple test voltages with the sensing voltages. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The foregoing and other objects, features and advantages of the present disclosure will become apparent from the following more particular description taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts in different views. The drawings are not necessarily drawn to scale, emphasis instead being placed upon illustrating the principles of the present disclosure.

[0012] Figure 1 A conventional multi-channel temperature sensing circuit in an electric vehicle battery power system is shown.

[0013] Figure 2 An exemplary multi-channel temperature sensing circuit with a fault detection system according to a first embodiment of the present disclosure is shown.

[0014] Figure 3 Shown Figure 2 An exemplary bias circuit in the fault detection system is shown.

[0015] Figure 4 is a flow chart of a temperature sensor group failure detection method according to the second embodiment of the present disclosure.

[0016] Figures 5a to 5c Shown Figure 4 The various states of the switches in the bias circuit used in the temperature sensor group fault detection method are shown. DETAILED DESCRIPTION

[0017] Many specific details of the present disclosure are described below, such as the structure, materials, dimensions, processing technology and techniques of the components, so as to provide a clearer understanding of the present disclosure. However, it will be understood by those skilled in the art that the present disclosure can be implemented without these specific details.

[0018] It should also be noted that in this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation and do not necessarily require or imply any actual relationship or order between these entities or operations. In addition, the words "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not preclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0019] Those of ordinary skill in the art will understand that the words "during", "when..." and "during..." used in this document for circuit operation do not strictly mean that the action occurs immediately when the startup action begins, but that there may be some small but reasonable delay after the reaction action triggered by the startup action, such as various transmission delays. As used herein, the words "approximately" or "substantially" indicate that an element has a parameter that is expected to be close to the declared value or position. However, as is well known in the art, there are always slight deviations that make it difficult for the value or position to be strictly equal to the declared value. It has been appropriately determined in the art that a deviation of at least ten percent (10%) is a reasonable deviation from the precise desired target (for semiconductor doping concentrations, at least twenty percent (20%)). When describing a signal in the context of a state, the actual voltage value or logic state of the signal (e.g., "1" or "0") depends on whether positive logic or negative logic is used.

[0020] Those skilled in the art will understand that the term "circuitry" may include a single or multiple hardware circuits, programmable circuits, state machine circuits, and / or a combination of components capable of storing instructions to be executed by a programmable circuit. In contrast, when an element is referred to as being "directly coupled" or "directly connected" to another element, it means that there are no intervening elements between the two.

[0021] Those skilled in the art will appreciate that the devices described herein are certain N-channel or P-channel devices, or certain N-type or P-type doped regions, and that complementary devices can also be realized based on the present disclosure. Those skilled in the art will understand that conductivity type refers to the mechanism by which conduction occurs, such as hole conduction or electron conduction. Therefore, conductivity type is not related to doping concentration, but rather to doping type, such as P-type or N-type.

[0022] Figure 1 The figure shows a conventional multi-channel temperature sensing circuit in an electric vehicle battery power system. In the battery power system, battery cells BAT1, BAT2, and BAT3 are interconnected within a battery pack 110 to provide sufficient power to drive the electric vehicle. Multi-channel temperature sensing circuit 100 includes a temperature sensor group 120 for providing a sensed voltage representing the temperature near battery cells BAT1, BAT2, and BAT3, and a conversion circuit 130 coupled to temperature sensor group 120 for converting the sensed voltage into a digital temperature value.

[0023] The temperature sensor group 120 has multiple channels. Figure 1 Three channels are shown in FIG. 1 , but this is not intended to limit the scope of the present disclosure, as the temperature sensor group 120 may include any number of channels for detecting temperatures at different locations of the battery power system.

[0024] In the first channel of temperature sensor group 120, the temperature sensor is shown as a negative temperature coefficient (NTC) resistor NTC1. However, this is not intended to limit the scope of this disclosure, as any temperature sensor having a parameter representing a temperature change can be used in the temperature sensor group. NTC resistor NTC1 and resistor R11 are coupled between a supply voltage VTS and ground, forming a resistor network that acts as a voltage divider. The resistance of NTC resistor NTC1 varies with temperature. A temperature-dependent sense voltage is generated at the node between NTC resistor NTC1 and resistor R11. RC filter 101 is coupled between pin P1 of conversion circuit 130 and the node between NTC resistor NTC1 and resistor R11. As an example, RC filter 101 includes resistor R12 and capacitors C11 and C12, with capacitor C11 coupled between one end of resistor R12 and ground, and capacitor C12 coupled between the other end of resistor R12 and ground. However, this is not intended to limit the scope of this disclosure, as any type of low-pass filter can be used in temperature sensor group 120 to filter out high-frequency interference in the sensed voltage.

[0025] The second and third channels of the temperature sensor group 120 have similar circuit structures to the first channel, and thus detailed descriptions are omitted.

[0026] Conversion circuit 130 includes an analog multiplexer (MUX) and an analog-to-digital converter (ADC). Analog multiplexer (MUX) has three inputs, coupled to the three channels of temperature sensor group 120, and one output, coupled to the input of ADC. Thus, analog multiplexer (MUX) couples selected analog inputs to the output in a time-division manner. ADC converts the sensed voltages from the three channels of temperature sensor group 120 into digital temperature values ​​(SEN[0:2]) and provides them to the controller chip of the battery power system.

[0027] exist Figure 1 In the figure, conversion circuit 130 is implemented as a conversion chip, and the dashed line represents the boundary of the conversion chip, but this is not intended to limit the scope of this disclosure. Instead, conversion circuit 130 can be part of a controller chip of the battery power system, and at least some components of temperature sensor group 120 can be integrated into the conversion chip or the controller chip. For example, all components of RC filters 101, 201, and 301, as well as resistors R11, R21, and R31, can be integrated into the conversion chip or the controller chip.

[0028] Figure 1 Traditional multi-channel temperature sensing circuits in a battery pack only provide a voltage to sense the temperature near the battery cells. Temperature sensors within the temperature sensor pack can be damaged by shorting or opening, resulting in incorrect temperature readings. The temperature sensor pack can be tested by isolating the NTC resistors in one channel from those in other channels. Because the battery power system includes a large number of NTC resistors, the test procedure would be unsuitable for road conditions, consuming excessive time and impacting normal operation of the electric vehicle.

[0029] Figure 2 An exemplary multi-channel temperature sensing circuit with a fault detection system according to a first embodiment of the present disclosure is shown. In a battery power system, battery cells BAT1, BAT2, and BAT3 are interconnected within a battery pack 110 to provide sufficient power to drive an electric vehicle. The multi-channel temperature sensing circuit 200 includes a temperature sensor group 120 for providing a sensed voltage representing the temperature near battery cells BAT1, BAT2, and BAT3, a conversion circuit 130 coupled to the temperature sensor group 120 for converting the sensed voltage into a digital value representing the temperature, and a fault detection system 210 coupled to the temperature sensor group 120 for executing a test program in real time.

[0030] The temperature sensor group 120 has multiple channels. Figure 2 Three channels are shown in FIG. 1 , but this is not intended to limit the scope of the present disclosure, as the temperature sensor group 120 may include any number of channels for detecting temperatures at different locations of the battery power system.

[0031] In the first channel of temperature sensor group 120, the temperature sensor is shown as a negative temperature coefficient (NTC) resistor NTC1. However, this is not intended to limit the scope of this disclosure, as any temperature sensor having a parameter representing a temperature change can be used in the temperature sensor group. NTC resistor NTC1 and resistor R11 are coupled between a supply voltage VTS and ground, forming a resistor network that acts as a voltage divider. The resistance of NTC resistor NTC1 varies with temperature. A temperature-dependent sense voltage is generated at the node between NTC resistor NTC1 and resistor R11. RC filter 101 is coupled between pin P1 of conversion circuit 130 and the node between NTC resistor NTC1 and resistor R11. As an example, RC filter 101 includes resistor R12 and capacitors C11 and C12, with capacitor C11 coupled between one end of resistor R12 and ground, and capacitor C12 coupled between the other end of resistor R12 and ground. However, this is not intended to limit the scope of this disclosure, as any type of low-pass filter can be used in temperature sensor group 120 to filter out high-frequency interference in the sensed voltage.

[0032] The second and third channels of the temperature sensor group 120 have similar circuit structures to the first channel, and thus detailed descriptions are omitted.

[0033] Conversion circuit 130 includes an analog multiplexer (MUX) and an analog-to-digital converter (ADC). Analog multiplexer (MUX) has three inputs, coupled to the three channels of temperature sensor group 120, and one output, coupled to the input of ADC. Thus, analog multiplexer (MUX) couples selected analog inputs to the output in a time-division manner. ADC converts the sensed voltages from the three channels of temperature sensor group 120 into digital temperature values ​​(SEN[0:2]) and provides them to the controller chip of the battery power system.

[0034] Fault detection system 210 includes a bias circuit 211 and a test controller 212 for controlling bias circuit 211 to execute a test procedure. Bias circuit 211 is coupled to pins P1, P2, and P3 of conversion circuit 130. Test controller 212 is coupled to bias circuit 211 to selectively pull down and / or pull up the voltages on pins P1, P2, and P3 to obtain a plurality of test voltages TEST[0:2]. Furthermore, test controller 212 determines faults in NTC sensors NTC1, NTC2, and NTC3 in temperature sensor group 120 by comparing sense voltages SEN[0:2] with test voltages TEST[0:2].

[0035] exist Figure 3In the exemplary bias circuit 211 shown, bias circuit 211 includes a plurality of switch units 211-1 to 211-3. The first switch unit 211-1 includes a resistor Rd1 and switches S11, S12, and S13. Switch S11 and resistor Rd1 are coupled between pin P1 of conversion circuit 130 and switch S13. Switch S12 is directly coupled between pin P1 of conversion circuit 130 and switch S13. Switch S13 is operable to select either a first preset voltage VL or a second preset voltage VH.

[0036] The first preset voltage VL is lower than the minimum sense voltage and is used to pull down the voltage on pins P1, P2, and P3 during the test process. For example, the first preset voltage VL is ground or zero voltage. The second preset voltage VH is higher than the maximum sense voltage and is used to pull up the voltage on pins P1, P2, and P3 during the test process. For example, the second preset voltage VH is a bias voltage lower than the power supply voltage of the multiple temperature sensors.

[0037] Therefore, the first switch unit 211-1 of the bias circuit 211 has a first pull-down path that directly couples the pin P1 to the first preset voltage, a second pull-down path that couples the pin P1 to the first preset voltage through the resistor Rd1, a first pull-up path that directly couples the pin P1 to the second preset voltage, and a second pull-up path that couples the pin P1 to the second preset voltage through the resistor Rd1.

[0038] Figure 3 The first switch unit 211-1 of the bias circuit 211 in the embodiment has the function of pulling up or down the voltage on the pins P1, P2, and P3 during the test procedure, but this is not intended to limit the scope of the present disclosure. Instead, when only the first preset voltage VL is provided as the bias voltage for pulling down the voltage on the pins P1, P2, and P3, or when only the second preset voltage VH is provided as the bias voltage for pulling up the voltage on the pins P1, P2, and P3, the first switch unit 211-1 of the bias circuit 211 can be simplified by omitting the switch S13.

[0039] The second switching unit 211 - 2 and the third switching unit 211 - 3 of the bias circuit 211 have similar circuit structures to the first switching unit 211 - 1 , and thus detailed descriptions are omitted.

[0040] The test controller 212 generates a switching signal SW for all switches in the bias circuit 211, so that pins P1 to P3 of the conversion circuit 130 can be directly coupled to the output of the temperature sensor group 120 to obtain the sensing voltage SEN[0:2] of the temperature sensor group 120, or can be pulled down to the first preset voltage VL through the first pull-down path or the second pull-down path to obtain the test voltage TEST[0:2] of the temperature sensor group 120, or can be pulled up to the second preset voltage VH through the first pull-up path or the second pull-up path to obtain the test voltage TEST[0:2] of the temperature sensor group 120.

[0041] exist Figure 2 In the figure, conversion circuit 130 is implemented as a conversion chip, and fault detection system 210 is implemented as a detection chip. The dotted line represents the boundary between the conversion chip and the detection chip, but this is not intended to limit the scope of this disclosure. Instead, conversion circuit 130 and fault detection system 210 can be part of a controller chip of the battery power system, and at least some components of temperature sensor group 120 can be integrated into the conversion chip or the controller chip. For example, all components of RC filters 101, 201, and 301, as well as resistors R11, R21, and R31, can be integrated into the conversion chip, the detection chip, or the controller chip.

[0042] Figure 2 The multi-channel temperature sensing circuit in the embodiment not only provides a sensed voltage for the temperature sensor group when fault detection system 210 is inactive, indicating the temperature near the battery cells, but also provides a test voltage for the temperature sensor group when fault detection system 210 is active, indicating a change in the sensed voltage for the temperature sensor group. During a test procedure, a pin of conversion circuit 130 is pulled down to a first preset voltage VL via the first pull-down path or the second pull-down path, or is pulled up to a second preset voltage VH via the first pull-up path or the second pull-up path.

[0043] This fault detection system is cost-effective because it reuses the existing analog-to-digital converter (ADC) in the battery power system. During the test procedure, there is no need to isolate the temperature sensor under test from the other temperature sensors in the temperature sensor group. The bias circuit and test controller in the fault detection system can have a simplified circuit structure because they only need to pull the output of the temperature sensor group down to a first preset voltage VL or up to a second preset voltage VH.

[0044] This fault detection system can measure half of the multiple pins at once and complete the test procedure after only two test voltage measurements. This shortens the test procedure and can be executed in real time under road conditions. Furthermore, the fault detection system can identify open and short circuit faults within each channel of the temperature sensor array, as well as short circuit faults between adjacent pins within the multiple pins of the conversion circuit.

[0045] Figure 4 is a flow chart of a temperature sensor group fault detection method according to a second embodiment of the present disclosure, Figures 5a to 5c Shown Figure 4 The various states of the switches in the bias circuit used in the temperature sensor group fault detection method are shown.

[0046] Fault detection methods will combine Figure 2 and Figure 3 The fault detection system shown in FIG. In this example, the bias circuit in the fault detection system is simplified to provide only a path that pulls down to ground. Therefore, a fault in the temperature sensor group 120 can be detected by comparing the sensed voltage of the temperature sensor group 120 with the test voltage. However, this is not intended to limit the scope of the present disclosure. Rather, any bias circuit can be used to generate a test voltage by providing a path that pulls down to a first preset voltage or a path that pulls up to a second preset voltage.

[0047] In step S01 , the fault detection system 210 measures the sense voltages at all pins of the conversion circuit 130 .

[0048] like Figure 5a As shown, in the fault detection system 210, the test controller 212 disables the bias circuit 211 by opening all switches in the bias circuit 211. Pins P1 to P3 of the conversion circuit 130 are directly coupled to the output of the temperature sensor group 120. The sensed voltage of the temperature sensor group 120 is determined by the NTC resistors NTC1 to NTC3 and represents the temperature near the battery cells of the battery power system.

[0049] The conversion circuit 130 receives the analog sensing voltage of the temperature sensor group 120 and provides digital values ​​SEN[0:2] of the sensing voltage of the temperature sensor group 120 to the test controller.

[0050] In steps S02 and S03 , the fault detection system 210 pulls down the voltage at the odd-numbered pins of the conversion circuit 130 to 0V, and couples the even-numbered pins of the conversion circuit 130 to resistors connected to ground.

[0051] like Figure 5bAs shown, in fault detection system 210, test controller 212 closes switches S12, S21, and S32, and opens switches S11, S22, and S31. Pins P1 and P3 of conversion circuit 130 are directly grounded via the second pull-down path of switch units 211-1 and 211-3. Pin P2 of conversion circuit 130 is grounded via the first pull-down path of switch unit 211-2, i.e., via resistor Rd2.

[0052] In step S04 , the fault detection system 210 measures the test voltage at the even-numbered pins of the conversion circuit 130 .

[0053] The odd-numbered pins P1 and P3 of conversion circuit 130 are directly grounded and therefore should have zero voltage. The even-numbered pin P2 of conversion circuit 130 is grounded via resistor Rd2 and therefore should have a test voltage lower than the sense voltage, given its connection within the resistor network of resistor R21 and NTC resistor NTC2. The test voltage at the even-numbered pins of conversion circuit 130 is determined by the NTC resistor and the resistor, and represents the change in the sensed voltage of the temperature sensor group when pin P2 of conversion circuit 130 is grounded via the first pull-down path.

[0054] The conversion circuit 130 receives the analog test voltage of the second channel of the temperature sensor group 120 and provides a digital value TEST[1] of the test voltage of the temperature sensor group 120 to the test controller.

[0055] In steps S05 and S06 , the fault detection system 210 pulls down the voltage at the even-numbered pins of the conversion circuit 130 to 0V, and couples the odd-numbered pins of the conversion circuit 130 to resistors connected to ground.

[0056] like Figure 5c As shown, in fault detection system 210, test controller 212 opens switches S12, S21, and S32, and closes switches S11, S22, and S31. Pin P2 of conversion circuit 130 is directly grounded via the second pull-down path of switch unit 211-2. Pins P1 and P3 of conversion circuit 130 are grounded via the first pull-down path of switch units 211-1 and 211-3, i.e., through resistors Rd1 and Rd3, respectively.

[0057] In step S07 , the fault detection system 210 measures the test voltages at the odd-numbered pins of the conversion circuit 130 .

[0058] The even-numbered pin P2 of the conversion circuit 130 is directly grounded and should therefore have zero voltage. The odd-numbered pins P1 and P3 of the conversion circuit 130 are grounded via resistors Rd1 and Rd3, respectively. Therefore, considering the connection of resistor Rd1 in the resistor network of resistor R11 and NTC resistor NTC1, and the connection of resistor Rd3 in the resistor network of resistor R31 and NTC resistor NTC3, they should have a test voltage lower than the sense voltage. The test voltage at the odd-numbered pins of the conversion circuit 130 is determined by the NTC resistor and the resistors, and represents the change in the sensed voltage of the temperature sensor group when pins P1 and P3 of the conversion circuit 130 are grounded via the first pull-down path.

[0059] The conversion circuit 130 receives the analog test voltage of the second channel of the temperature sensor group 120 and provides digital values ​​TEST[0] and TEST[2] of the test voltage of the temperature sensor group 120 to the test controller.

[0060] In step S08 , the fault detection system 210 determines faults at all pins of the conversion circuit 130 by comparing the sense voltage SEN[0:2] and the test voltage TEST[0:2].

[0061] At each pin of the conversion circuit 130 , the test voltage should slightly drop relative to the sense voltage due to the connection of the resistors in the resistor network, indicating that the temperature sensor group 120 is in a normal state.

[0062] If the test voltage approaches 0, a short circuit fault may occur between adjacent pins of the conversion circuit 130, an open circuit fault may occur in the corresponding channel of the temperature sensor group 120, or a short circuit fault may occur in the corresponding channel of the temperature sensor group 120. If the test voltage does not drop relative to the sense voltage, there is a problem with the bias circuit.

[0063] The fault detection method can measure half of the multiple pins at once and complete the test procedure after only two test voltage measurements. This shortens the test procedure and can be executed in real time under road conditions. Furthermore, the fault detection method can identify open and short circuit faults within each channel of the temperature sensor array, as well as short circuit faults between adjacent pins within the multiple pins of the conversion circuit.

[0064] In the above embodiments, the bias circuit is described as providing a first pull-down path and a second pull-down path to ground at each pin of the conversion circuit, but this is not intended to limit the scope of the present disclosure. Instead, the bias circuit can provide the first pull-down path and the second pull-down path to a first preset voltage below the minimum value of the sensing voltage, and / or provide the first pull-up path and the second pull-up path to a second preset voltage above the maximum value of the sensing voltage. In addition, the first pull-down path and the second pull-down path in the bias circuit, and / or the first pull-up path and the second pull-up path can be coupled to nodes of the corresponding resistor network of the temperature sensor group. The fault detection system can still determine faults at all pins of the conversion circuit by comparing the sensing voltage and the test voltage.

[0065] In a preferred embodiment, the bias circuit can provide first and second pull-down paths to ground, and first and second pull-up paths to the supply voltage VTS of the temperature sensor group. Two test voltages are obtained at a pin of the conversion circuit, with the pin grounded via the second pull-down circuit and the pin coupled to the supply voltage VTS via the second pull-up circuit. If the test voltages approach zero or the supply voltage VTS, a short circuit fault will occur between adjacent pins of the conversion circuit, an open circuit fault will occur in the corresponding channel of the temperature sensor group 120, or a short circuit fault will occur in the corresponding channel of the temperature sensor group 120. If the test voltages do not drop relative to the sense voltage, there is a problem with the bias circuit. Fault detection can be verified by comparing the two test voltages at each pin of the conversion circuit with the sense voltage.

[0066] While the foregoing embodiments of the present disclosure have been presented, these embodiments do not describe all details, nor do they limit the present disclosure to the specific embodiments described. Clearly, many modifications and variations are possible based on the foregoing description. These embodiments have been selected and described in detail in this specification to better explain the principles and practical applications of the present disclosure, thereby enabling those skilled in the art to fully utilize the present disclosure and make modifications based on the present disclosure. The present disclosure is limited only by the claims and their full scope and equivalents.

Claims

1. A fault detection system (210) for a temperature sensor group (120), the temperature sensor group (120) comprising a plurality of temperature sensors (NTC1, NTC2, NTC3) for providing a multi-channel sensing voltage at a plurality of pins (P1, P2, P3) of a conversion circuit (130), the fault detection system (210) comprising: a bias circuit (211); as well as a test controller (212) coupled to the bias circuit (211) and configured to control the bias circuit (211) to selectively pull down and / or pull up the voltages on the plurality of pins (P1, P2, P3) to obtain a plurality of test voltages, The test controller (212) determines a fault of the temperature sensor group (120) by comparing the sensed voltage and the test voltage.

2. The fault detection system (210) according to claim 1, wherein: Each channel of the temperature sensor group (120) includes a resistor network of the temperature sensor (NTC1, NTC2, NTC3) for providing a sense voltage at a node of the resistor network.

3. The fault detection system (210) according to claim 2, wherein: The bias circuit (211) is coupled to the plurality of pins (P1, P2, P3) of the conversion circuit (130), or coupled to the resistor network of the temperature sensor (NTC1, NTC2, NTC3) of the temperature sensor group (120).

4. The fault detection system (210) according to claim 2, wherein: The bias circuit (211) provides at least one of the following for each channel of the temperature sensor group (120): a first pull-down path, a second pull-down path, a first pull-up path, and a second pull-up path. The first pull-down path directly pulls down the channel output of the temperature sensor group (120) to a first preset voltage, The second pull-down path pulls down the channel output of the temperature sensor group (120) to the first preset voltage through resistors (Rd1; Rd2; Rd3). The first pull-up path directly pulls up the channel output of the temperature sensor group (120) to a second preset voltage, and the second pull-up path pulls up the channel output of the temperature sensor group (120) to the second preset voltage through the resistor (Rd1; Rd2; Rd3).

5. The fault detection system (210) according to claim 4, wherein: The first preset voltage is lower than a minimum value of the sensing voltage, and the second preset voltage is higher than a maximum value of the sensing voltage.

6. The fault detection system (210) according to claim 5, wherein: The first preset voltage is a ground voltage or a zero voltage, and the second preset voltage is lower than or equal to a supply voltage of the plurality of temperature sensors (NTC1, NTC2, NTC3).

7. The fault detection system (210) according to claim 4, wherein: The bias circuit (211) includes a plurality of switch units (211-1, 211-2, 211-3), each of the switch units (211-1, 211-2, 211-3) including the resistor (Rd1; Rd2; Rd3) and a plurality of switches (S11, S12, S13; S21, S22, S23; S31, S32, S33), the plurality of switches being coupled to the resistor (Rd1; Rd2; Rd3) and operable to change the connection between one of the plurality of pins (P1, P2, P3) and one of the first and second preset voltages.

8. The fault detection system (210) of claim 1, wherein: The test controller (212) obtains a first test voltage when: the bias circuit (211) is activated to directly pull down a second pin (P1, P3) of the plurality of pins (P1, P2, P3) to a first preset voltage, and pulls down a first pin (P2) of the plurality of pins (P1, P2, P3) to the first preset voltage through resistors (Rd1, Rd2, Rd3); and obtains a second test voltage when: the bias circuit (211) is activated to directly pull down a first pin (P2) of the plurality of pins (P1, P2, P3) to the first preset voltage, and pulls down a second pin (P1, P3) of the plurality of pins (P1, P2, P3) to the first preset voltage through resistors (Rd1, Rd2, Rd3); and / or The test controller (212) obtains a third test voltage when: the bias circuit (211) is activated to directly pull up the second pin (P1, P3) among the multiple pins (P1, P2, P3) to a second preset voltage, and pulls up the first pin (P2) among the multiple pins (P1, P2, P3) to the second preset voltage through resistors (Rd1, Rd2, Rd3); and obtains a fourth test voltage when: the bias circuit (211) is activated to directly pull up the first pin (P2) among the multiple pins (P1, P2, P3) to the second preset voltage, and pulls up the second pin (P1, P3) among the multiple pins (P1, P2, P3) to the second preset voltage through resistors (Rd1, Rd2, Rd3).

9. The fault detection system (210) according to claim 8, wherein: The first pin (P2) among the plurality of pins (P1, P2, P3) is an even-numbered pin of the conversion circuit (130), and the second pin (P1, P3) among the plurality of pins (P1, P2, P3) is an odd-numbered pin of the conversion circuit (130).

10. The fault detection system (210) of claim 1, wherein: The plurality of temperature sensors (NTC1, NTC2, NTC3) are negative temperature coefficient resistors.

11. A multi-channel temperature sensing circuit (200) in a battery power system, comprising: a temperature sensor group (120) having a plurality of channels to provide a multi-channel sensing voltage, each of the plurality of channels having a temperature sensor; a conversion circuit (130) coupled to the temperature sensor group (120) to convert the analog value of the sensed voltage into a digital value; as well as The fault detection system (210) according to any one of claims 1 to 10, configured to detect a fault of the temperature sensor group (120) according to a test procedure, The temperature sensor group (120) detects the temperature near the battery cells (BAT1, BAT2, BAT3) of the battery power system.

12. A fault detection method for a temperature sensor group (120), the temperature sensor group (120) comprising a plurality of temperature sensors (NTC1, NTC2, NTC3) for providing a multi-channel sensing voltage at a plurality of pins (P1, P2, P3) of a conversion circuit (130), the fault detection method comprising: measuring a sense voltage at the plurality of pins (P1, P2, P3); measuring a plurality of test voltages at the plurality of pins (P1, P2, P3) while the plurality of pins (P1, P2, P3) are selectively pulled down to a first preset voltage and / or pulled up to a second preset voltage; A fault of the temperature sensor group (120) is determined by comparing the plurality of test voltages with the sensed voltage.

13. The fault detection method according to claim 12, wherein: The step of measuring a plurality of test voltages at the plurality of pins (P1, P2, P3) comprises: While a second pin (P1, P3) of the plurality of pins (P1, P2, P3) is directly pulled down to the first preset voltage, and the first pin (P2) of the plurality of pins (P1, P2, P3) is pulled down to the first preset voltage via a resistor (Rd1, Rd2, Rd3), measuring a first test voltage at a first pin (P2) of the plurality of pins (P1, P2, P3), each of the first pins being adjacent to a corresponding one of the second pins of the plurality of pins (P1, P2, P3); while the first pin (P2) among the plurality of pins (P1, P2, P3) is directly pulled down to the first preset voltage, and the second pin (P1, P3) among the plurality of pins (P1, P2, P3) is pulled down to the first preset voltage through resistors (Rd1, Rd2, Rd3), measuring a second test voltage at the second pin (P1, P3) among the plurality of pins (P1, P2, P3); and / or while the second pin (P1, P3) among the plurality of pins (P1, P2, P3) is directly pulled up to the second preset voltage and the first pin (P2) among the plurality of pins (P1, P2, P3) is pulled up to the second preset voltage through the resistor (Rd1, Rd2, Rd3), measuring a third test voltage at the first pin (P2) among the plurality of pins (P1, P2, P3), each of the first pins being adjacent to a corresponding one of the second pins among the plurality of pins (P1, P2, P3); While the first pin (P2) among the multiple pins (P1, P2, P3) is directly pulled up to the second preset voltage, and the second pin (P1, P3) among the multiple pins (P1, P2, P3) is pulled up to the second preset voltage through resistors (Rd1, Rd2, Rd3), a fourth test voltage is measured at the second pin (P1, P3) among the multiple pins (P1, P2, P3).

14. The fault detection method according to claim 13, wherein: The first pin (P2) among the plurality of pins (P1, P2, P3) is an even-numbered pin of the conversion circuit (130), and the second pin (P1, P3) among the plurality of pins (P1, P2, P3) is an odd-numbered pin of the conversion circuit (130).

15. The fault detection method according to claim 12, wherein: The first preset voltage is lower than a minimum value of the sensing voltage, and the second preset voltage is higher than a maximum value of the sensing voltage.

16. The fault detection method according to claim 15, wherein: The first preset voltage is a ground voltage or a zero voltage, and the second preset voltage is lower than or equal to a supply voltage of the plurality of temperature sensors (NTC1, NTC2, NTC3).

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