Failure detection for temperature sensor cluster

Abstract

A system for carrying out failure detection for a temperature sensor cluster (120). The temperature sensor cluster (120) includes a plurality of temperature sensors (NTC1, NTC2, NTC3) which provide multi-channel sensing voltages at a plurality of pins (P1, P2, P3) of a conversion circuit (130). A bias circuit (211) is controlled by a test controller (212), so as to selectively pull down and / or pull up voltages at the plurality of pins (P1, P2, P3) to obtain a plurality of testing voltages. The test controller (212) determines faults of the temperature sensor cluster (120) by comparing the sensing voltages and the testing voltages. The failure detection system (210) can measure one half of the plurality of pins (P1, P2, P3) one time and thus can perform a test procedure in a real-time manner in road situations. Moreover, the failure detection system (210) can identify both open-circuit and short-circuit faults in each channel of the temperature sensor cluster (120) and short-circuits between adjacent ones of the plurality of pins (P1, P2, P3) of the conversion circuit (130). And a method for carrying out failure detection for a temperature sensor cluster (120) is also provided.

Description

FAILURE DETECTION FOR TEMPERATURE SENSOR CLUSTERTechnical Field

[0001] The present disclosure generally relates to electronic circuits, and more particularly, to failure detection for a temperature sensor cluster.Background

[0002] A temperature sensor cluster comprises a collection of temperature sensors deployed within a system or apparatus to monitor temperature variances across numerous locations. In the battery power system of an electric vehicle (EV), numerous battery cells within a battery pack are interconnected to provide adequate power for propelling the electric vehicle. The temperature sensor cluster is integrated into the battery power system to monitor the temperature of diverse battery cells within the battery pack, ensuring the secure and efficient functionality of the battery system.

[0003] Leakage current within the battery pack poses a significant concern as it can lead to various adverse effects, including reduced battery efficiency, accelerated degradation, and potential safety hazards. Additionally, leakage current can contribute to localized heating within the battery pack, exacerbating thermal management challenges and increasing the risk of thermal runaway events. One effective way to determine the presence of leakage current is by detecting the temperature near the battery cells.

[0004] By monitoring the temperature in the vicinity of the battery cells, it is possible to identify any abnormal rise in temperature, which can be indicative of leakage current. This can be done using various temperature sensing techniques such as thermocouples, infrared sensors, or thermal imaging cameras. Once identified, appropriate measures can be taken to mitigate the issue, such as isolating or replacing the faulty battery cells. Monitoring temperature near the battery cells, especially in a timely manner, allows for timely intervention and prevents potential damage or safety hazards.

[0005] However, the temperature sensors in the temperature sensor cluster may be damaged due to short circuits or open circuits, thus indicating incorrect values of the temperature. The electric vehicle includes numerous battery cells and temperature sensors in the power battery system. Even if one temperature sensor is damaged, the electric vehicle may be intervened incorrectly and cannot be operated normally.

[0006] Conventional systems and methods of failure detection for temperature sensor clusters in the battery power system involve testing numerous temperature sensors individually. These methods require isolating the temperature sensor to be tested from the others, which is not suitable for road situations because the test procedure takes too long for the normal operation of the electric vehicle.

[0007] Therefore, it is required that the system and method overcome the shortcomings of failure detection for temperature sensor clusters.Summary of the Disclosure

[0008] According to one aspect of the present disclosure, there is a provided a failure detection system for a temperature sensor cluster. The temperature sensor cluster includes a plurality of temperature sensors to provide multi-channel sensing voltages at a plurality of pins. The failure detection system comprises: a bias circuit; and a test controller being coupled with the bias circuit, and configured to control the bias circuit to selectively pull down and / or pull up voltages at the plurality of pins to obtain a plurality of testing voltages, wherein the test controller determines faults of the temperature sensor cluster by comparing the sensing voltages and the testing voltages.

[0009] According to another aspect of the present disclosure, there is provided a multi-channel temperature sensing circuit in a battery power system, comprising: a temperature sensor cluster having a plurality of channels to provide multi-channel sensing voltages, each of the plurality of channels having a temperature sensor; a conversion circuit being coupled with the temperature sensor cluster to convert analog values to digital values of the sensing voltages; and a failure detection system as mentioned above for detecting faults of the temperature sensor cluster in a test procedure, wherein temperature sensor cluster detects temperatures at various locations near battery cells of the battery power system.

[0010] According to another aspect of the present disclosure, there is provided a failure detection method for a temperature sensor cluster. The temperature sensor cluster includes a plurality of temperature sensors to provide multi-channel sensing voltages at a plurality of pins. The failure detection method comprises: measuring sensing voltages at the plurality of pins; measuring a plurality of testing voltages at the plurality of pins while the plurality of pins are selectively pulled down to a first preset voltage and / or pulled up to a second preset voltage; determining faults of the temperature sensor cluster by comparing the plurality of testing voltages with the sensing voltages.Detailed Description of the Disclosure

[0011] The foregoing and other objects, features and advantages of the disclosure will be apparent from the following more particular description of preferred embodiments of the disclosure, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosure.

[0012] FIG. 1 illustrates a conventional multi-channel temperature sensing circuit in a battery power system of an electric vehicle.

[0013] FIG. 2 illustrates an exemplary multi-channel temperature sensing circuit having a failure detection system in a battery power system of an electric vehicle according to a first embodiment of the present disclosure.

[0014] FIG. 3 illustrates an exemplary bias circuit in the failure detection system shown in FIG. 2.

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

[0016] FIGs. 5a to 5c illustrate various states of switches in the bias circuit in the failure detection method for the temperature sensor cluster shown in FIG. 4Specific Embodiment

[0017] Many specific details of the present disclosure, such as the structure, material, dimensions, treatment processes, and techniques of the components, are described below for more clear understanding of the present disclosure. However, as will be appreciated by those skilled in the art, the present disclosure may not be practiced in accordance with these specific details.

[0018] It should also be noted that in this description, relational terms such as first and second are merely used to distinguish one entity or operation from another, and do not necessarily require or imply that there is any such actual relationship or sequence among these entities or operations. Furthermore, the word "include", "contain", or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements includes not only those elements, but other elements that are not explicitly listed or elements inherent to such process, method, article, or device. In the absence of further limitations, elements defined by the phrase "comprises a…" do not exclude the presence of additional identical elements in the process, method, article, or device that includes the elements.

[0019] It will be appreciated by those of ordinary skill in the art that the words "during", "when", and "while" used herein in connection with circuit operation are not strict terms for actions that occur immediately at the beginning of a start action, but that there may be some small but reasonable one or more delays after a reaction action initiated by a start action, such as various transmission delays, etc. As used herein, the word "approximately" or "substantially" means an element has a parameter that is expected to approximate the declared value or location. However, as is well known in the art, there are always minor deviations that make it difficult to have the value or position to be strictly the declared value. It has been properly determined in the art that a deviation of at least ten percent (10%) is a reasonable deviation from the precise desired target described (for a doping concentration of semiconductor, at least twenty percent (20%)). When a signal is described in the context of a state, an actual voltage value or logic state of the signal (e.g. "1" or "0") depends on whether positive or negative logic is used.

[0020] It will be appreciated by those of ordinary skill in the art that the word "circuit" may include single or multiple combinations of hardware circuits, programmable circuits, state machine circuits, and / or components capable of storing instructions which are executed by a programmable circuit. Conversely, when the element is said to be "directly coupled" or "directly connected" to another element, it means that there is no intermediate element therebetween.

[0021] It will be appreciated by those of ordinary skill in the art that the device is described herein as some kind of N-channel or P-channel device, or some kind of N-type or P-type doped region, it will be appreciated by those of ordinary skill in the art that complementary devices can also be implemented in accordance with the present disclosure. It will be appreciated by those of ordinary skill in the art that the type of conductivity refers to the mechanism that conduction occurs, such as hole conductivity or electron conductivity. Therefore, the type of conductivity does not relate to a doping concentration, but to the type of doping, such as P-type or N-type.

[0022] FIG. 1 illustrates a conventional multi-channel temperature sensing circuit in a battery power system of an electric vehicle. In the battery power system, battery cells BAT1, BAT2 and BAT3 are interconnected within a battery pack 110 to provide adequate power for propelling the electric vehicle. The multi-channel temperature sensing circuit 100 comprises a temperature sensor cluster 120 for providing sensing voltages which represent temperatures at various locations near the battery cells BAT1, BAT2 and BAT3, and a conversion circuit 130 which is coupled with the temperature sensor cluster 120 for converting the sensing voltages into digital values of the temperatures.

[0023] The temperature sensor cluster 120 has a plurality of channels, which is depicted as three channels in FIG. 1, but this is not intended to limit the scope of the disclosure, because any number of channels may be included in the temperature sensor cluster 120 for detecting temperature at different locations of the battery power system.

[0024] In a first channel of the temperature sensor cluster 120, the temperature sensor is shown as a Negative temperature coefficient (NTC) resistor NTC1, but this is not intended to limit the scope of the disclosure, because any temperature sensor that have varied parameters which representing temperature variations may be used in the temperature sensor cluster. The NTC resistor NTC1 is coupled with resistor R11 between a supply voltage VTS and ground to form a resistor network and function as a voltage divider. The NTC resistor NTC1 has a resistance value that varies with the temperature. A sensing voltage is generated at a node between the NTC resistor NTC1 and the resistor R11 and varies with temperature. An RC filter 101 is coupled between pin P1 of the conversion circuit 130 and the node between the NTC resistor NTC1 and the resistor R11. As an example, the RC filter 101 includes resistor R12 and capacitors C11 and C12, with the capacitor C11 being coupled between one end of the resistor R12 and ground and the capacitor C12 being coupled between the other end of the resistor R12 and ground, but this is not intended to limit the scope of the disclosure, because any type of low-pass filter may be used in the temperature sensor cluster 120 for filtering out high-frequency interference in the sensing voltages .

[0025] A second and a third channel of the temperature sensor cluster 120 have circuit structures similar to that of the first channel of the temperature sensor cluster 120, and thus detailed description will be omitted.

[0026] The conversion circuit 130 includes an analog multiplexer MUX and an analog-to-digital converter ADC. The analog multiplexer MUX have three inputs that is coupled with three channels of the temperature sensor cluster 120 respectively, and one output that is coupled with an input of the analog-to-digital converter ADC. Thus, the analog multiplexer MUX has a selected analog input to be coupled with the one output in a time-division manner. The analog-to-digital converter ADC converts sensing voltages of the three channels of the temperature sensor cluster 120 into digital values SEN[0:2] of the temperature, and provides them to a controller chip of the battery power system.

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

[0028] The conventional multi-channel temperature sensing circuit in FIG. 1 has only the function of providing sensing voltages of temperatures at various locations near the battery cells. The temperature sensors in the temperature sensor cluster may be damaged due to short circuits or open circuits, thus indicating incorrect values of the temperature. The temperature sensor cluster may be tested by isolating an NTC resistor in one channel from those in other channels. Because a battery power system includes numerous NTC resistors, a test procedure will be not suitable for road situations because it takes too long for normal operation of an electric vehicle.

[0029] FIG. 2 illustrates an exemplary multi-channel temperature sensing circuit having a failure detection system in a battery power system of an electric vehicle according to a first embodiment of the present disclosure. In the battery power system, battery cells BAT1, BAT2 and BAT3 are interconnected within a battery pack 110 to provide adequate power for propelling the electric vehicle. The multi-channel temperature sensing circuit 200 comprises a temperature sensor cluster 120 for providing sensing voltages which represent temperatures at various locations near the battery cells BAT1, BAT2 and BAT3, a conversion circuit 130 which is coupled with the temperature sensor cluster 120 for converting the sensing voltages into digital values of the temperatures, and a failure detection system 210 which is coupled with the temperature sensor cluster 120 for performing a test procedure in a real-time manner.

[0030] The temperature sensor cluster 120 has a plurality of channels, which is depicted as three channels in FIG. 2, but this is not intended to limit the scope of the disclosure, because any number of channels may be included in the temperature sensor cluster 120 for detecting temperatures at different locations of the battery power system.

[0031] In a first channel of the temperature sensor cluster 120, the temperature sensor is shown as a Negative temperature coefficient (NTC) resistor NTC1, but this is not intended to limit the scope of the disclosure, because any temperature sensor that have varied parameters which representing temperature variations may be used in the temperature sensor cluster. The NTC resistor NTC1 is coupled with resistor R11 between a supply voltage VTS and ground to form a resistor network and function as a voltage divider. The NTC resistor NTC1 has a resistance value that varies with the temperature. A sensing voltage is generated at a node between the NTC resistor NTC1 and the resistor R11 and varies with temperature. An RC filter 101 is coupled between pin P1 of the conversion circuit 130 and the node between the NTC resistor NTC1 and the resistor R11. As an example, the RC filter 101 includes resistor R12 and capacitors C11 and C12, with the capacitor C11 being coupled between one end of the resistor R12 and ground and the capacitor C12 being coupled between the other end of the resistor R12 and ground, but this is not intended to limit the scope of the disclosure, because any type of low-pass filter may be used in the temperature sensor cluster 120 for filtering out high-frequency interference in the sensing voltages .

[0032] A second and a third channel of the temperature sensor cluster 120 have circuit structures similar to that of the first channel of the temperature sensor cluster 120, and thus detailed description will be omitted.

[0033] The conversion circuit 130 includes an analog multiplexer MUX and an analog-to-digital converter ADC. The analog multiplexer MUX have three inputs that is coupled with three channels of the temperature sensor cluster 120 respectively, and one output that is coupled with an input of the analog-to-digital converter ADC. Thus, the analog multiplexer MUX has a selected analog input to be coupled with the one output in a time-division manner. The analog-to-digital converter ADC converts sensing voltages of the three channels of the temperature sensor cluster 120 into digital values SEN[0:2] of the temperature, and provides them to a controller chip of the battery power system.

[0034] The failure detection system 210 includes a bias circuit 211 and a test controller 212 for controlling the bias circuit 211 to perform a test procedure. The bias circuit 211 is coupled with pins P1, P2 and P3 of the conversion circuit 130. The test controller 212 is coupled with the bias circuit 211 to selectively pull down and / or pull up voltages at the pins P1, P2 and P3 to obtain a plurality of testing voltages TEST[0:2]. Further, the test controller 212 determines failure of the NTC sensors NTC1, NTC2 and NTC3 in the temperature sensor cluster 120 by comparing the sensing voltages SEN[0:2] and the testing voltages TEST[0:2].

[0035] In an exemplary bias circuit 211 as shown in FIG. 3, the bias circuit 211 includes a plurality of switching units 211-1 to 211-3. A first switching unit 211-1 includes a resistor Rd1, and switches S11, S12 and S13. The switch S11 is coupled with the resistor Rd1 between the pin P1 of the conversion circuit 130 and the switch S13, and the switch S12 is coupled directly between the pin P1 of the conversion circuit 130 and the switch S13. The switch S13 is operable to select one of a first preset voltage VL and a second preset voltage VH.

[0036] The first preset voltage VL is lower than a minimum value of the sensing voltage, and is used for pulling down voltages at the pins P1, P2 and P3 in a test procedure. For example, the first preset voltage VL is a ground voltage or a zero voltage. The second preset voltage VH is higher than a maximum value of the sensing voltage, and is used for pulling up voltages at the pins P1, P2 and P3 in a test procedure. For example, the second preset voltage VH is a bias voltage lower than a supply voltage of the plurality of temperature sensors.

[0037] Thus, the first switching unit 211-1 of the bias circuit 211 has a first pull-down path by directly coupling the pin P1 to the first preset voltage, a second pull-down path by coupling the pin P1 to the first preset voltage through the resistor Rd1, a first pull-up path by directly coupling the pin P1 to the second preset voltage, a second pull-up path by coupling the pin P1 to the second preset voltage through the resistor Rd1.

[0038] The first switching unit 211-1 of the bias circuit 211 in FIG. 3 has both the functions of pulling up or pulling down voltages at the pins P1, P2 and P3 in a test procedure, but this is not intended to limit the scope of the disclosure. Instead, the first switching unit 211-1 of the bias circuit 211 may be simplified by omitting the switch S13 in a case that only the first preset voltage VL is provided as a bias voltage for pulling down the voltages at the pins P1, P2 and P3, or in a case that only the second preset voltage VH is provided as a bias voltage for pulling up the voltages at the pins P1, P2 and P3.

[0039] A second switching unit 211-2 and a third switching unit 211-3 of the bias circuit 211 have circuit structures similar to that of the first switching unit 211-1 of the bias circuit 211, and thus detailed description will be omitted.

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

[0041] In FIG. 2, the conversion circuit 130 is implemented as a conversion chip, the failure detection system 210 is implemented as a detection chip, and dashed lines indicate a boundary of the conversion chip and a boundary of the detection chip, but this is not intended to limit the scope of the disclosure. Instead, the conversion circuit 130 and the failure detection system 210 may be portions of the controller chip of the battery power system, and at least some components of the temperature sensor cluster 120 may be integrated into the conversion chip or the controller chip. For example, all components of RC filters 101, 201 and 301, and the resistors R11, R21 and R31, may be integrated into the conversion chip, the detection chip or the controller chip.

[0042] The multi-channel temperature sensing circuit in FIG. 2 has both the functions of providing sensing voltages of the temperature sensor cluster in a case that the failure detection system 210 is not activated, which represents temperatures at various locations near the battery cells, and of providing testing voltages of the temperature sensor cluster in a test procedure in a case that the failure detection system 210 is activated, which represents variations of the sensing voltages of the temperature sensor cluster. In the test procedure, the pins of the conversion circuit 130 are pulled down to the first preset voltage VL through the first pull-down path or the second pull-down path, or pulled up to the second preset voltage VH through the first pull-up path or the second pull-up path.

[0043] The failure detection system is cost-effective because it reuses the existing analog-to-digital converter (ADC) in the battery power system. During a test procedure, there is no need to isolates the temperature sensor to be tested from the others in the temperature sensor cluster. The bias circuit and the test controller in the failure detection system may have simplified circuit structures because only the outputs of the temperature sensor cluster need to be pulled down to a first preset voltage VL or pulled up to a second preset voltage VH.

[0044] The failure detection system can measure one half of the plurality of pins one time, and the test procedure may be completed after measuring the testing voltages only two times. Thus, the test procedure will take short time, and may be performed in a real-time manner in road situations. Moreover, the failure detection system can identify both open-circuit and short-circuit faults in each channel of the temperature sensor cluster and short-circuits between adjacent ones of the plurality of pins of the conversion circuit.

[0045] FIG. 4 is a flow chart of a failure detection method for a temperature sensor cluster according to a second embodiment of the present disclosure, and FIGs. 5a to 5c illustrate various states of switches in the bias circuit in the failure detection method for the temperature sensor cluster shown in FIG. 4.

[0046] The failure detection method will be described in connection with the failure detection system shown in FIGs. 2 and 3. In this example, the bias circuit in the failure detection system is simplified to provide only pull-down paths to ground, so that failure of the temperature sensor cluster 120 may be detected by comparing sensing voltages and testing voltages of the temperature sensor cluster 120, but this is not intended to limit the scope of the disclosure. Instead, any bias circuit may be used to generate testing voltages by providing pull-down paths to a first preset voltage or providing pull-up paths to a second preset voltage.

[0047] At step S01, the fault detection system 210 measure sensing voltage at all pins of the conversion circuit 130.

[0048] As shown in FIG. 5a, in the failure detection system 210, the test controller 212 disables the bias circuit 211 by opening all of the switches the bias circuit 211. The pins P1 to P3 of the conversion circuit 130 will be directly coupled with the outputs of the temperature sensor cluster 120. The sensing voltages of the temperature sensor cluster 120 are determined by the NTC resistors NTC1 to NTC3, and represent temperatures at various locations near the battery cells of the battery power system.

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

[0050] At steps S02 and S03, the fault detection system 210 pulls down voltages at odd pins of the conversion circuit 130 to 0V, and couples even pins of the conversion circuit 130 to the resistors that are grounded.

[0051] As shown in FIG. 5b, in the failure detection system 210, the test controller 212 closes switches S12, S21 and S32, and opens switches S11, S22 and S31. The pins P1 and P3 of the conversion circuit 130 will be grounded directly through the second pull-down path of the switching units 211-1 and 211-3. The pin P2 of the conversion circuit 130 will be grounded through the first pull-down path of the switching unit 211-2, i.e. , through the resistor Rd2.

[0052] At step S04, the fault detection system 210 measure testing voltage at even pins of the conversion circuit 130.

[0053] The odd pins P1 and P3 of the conversion circuit 130 are grounded directly, and thus should have a zero voltage. The even pin P2 of the conversion circuit 130 are grounded through the resistor Rd2, and thus should have a testing voltage that is lower than a sensing voltage, in view of the connection of the resistor Rd2 in the resistor network of the resistor R21 and the NTC resistor NTC2. The testing voltage at the even pin of the conversion circuit 130 is determined by the NTC resistor and the resistor, and represents variations of the sensing voltage of the temperature sensor cluster in a case that the pin P2 of the conversion circuit 130 is ground through the first pull-down path.

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

[0055] At steps S05 and S06, the fault detection system 210 pulls down voltage at even pins of the conversion circuit 130 to 0V, and couples odd pins of the conversion circuit 130 to the resistors that are grounded.

[0056] As shown in FIG. 5c, in the failure detection system 210, the test controller 212 opens switches S12, S21 and S32, and closes switches S11, S22 and S31. The pin P2 of the conversion circuit 130 will be grounded directly through the second pull-down path of the switching unit 211-2. The pins P1 and P3 of the conversion circuit 130 will be grounded through the first pull-down path of the switching units 211-1 and 211-3, i.e. , through the resistors Rd1 and Rd3 respectively.

[0057] At step S07, the fault detection system 210 measure testing voltage at odd pins of the conversion circuit 130.

[0058] The even pin P2 of the conversion circuit 130 is grounded directly, and thus should have a zero voltage. The odd pins P1 and P3 of the conversion circuit 130 are grounded through the resistors Rd1 and Rd3 respectively, and thus should have testing voltages that are lower than sensing voltages, in view of the connection of the resistor Rd1 in the resistor network of the resistor R11 and the NTC resistor NTC1 and the connection of the resistor Rd3 in the resistor network of the resistor R31 and the NTC resistor NTC3. The testing voltages at the odd pins of the conversion circuit 130 are determined by the NTC resistor and the resistor, and represent variations of the sensing voltages of the temperature sensor cluster in a case that the pins P1 and P3 of the conversion circuit 130 are ground through the first pull-down path.

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

[0060] At step S08, the fault detection system 210 determines faults at all pins of the conversion circuit 130 by comparing the sensing voltages SEN[0:2] and the testing voltages TEST[0:2].

[0061] At each pin of the conversion circuit 130, the testing voltage should decrease a little with respect to the sensing voltage due to the connection of the resistor in the resistor network, which indicates a normal state of the temperature sensor cluster 120.

[0062] If the testing voltage is close to 0, there will be a short-circuit fault that occurs between adjacent pins of the conversion circuit 130, or an open-circuit fault in the corresponding channel of the temperature sensor cluster 120, or a short-circuit fault in the corresponding channel of the temperature sensor cluster 120. If the testing voltage does not decrease with respect to the sensing voltage, there is an issue in the bias circuit.

[0063] The failure detection method can measure one half of the plurality of pins one time, and may complete the test procedure after measuring the testing voltages only two times. Thus, the test procedure will take short time, and may be performed in a real-time manner in road situations. Moreover, the failure detection method can identify both open-circuit and short-circuit faults in each channel of the temperature sensor cluster and short-circuits between adjacent ones of the plurality of 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 conversing circuit, but this is not intended to limit the scope of the disclosure. Instead, the bias circuit may provide a first pull-down path and a second pull-down path to a first preset voltage that is lower than a minimum value of the sensing voltages, and / or provide a first pull-up path and a second pull-up path to a second preset voltage is higher than a maximum value of the sensing voltages. Moreover, the first pull-down path and the second pull-down path, and / or the first pull-up path and the second pull-up path in the bias circuit may be coupled with the node of the corresponding resist network in the temperature sensor cluster. The fault detection system can still determines faults at all pins of the conversion circuit by comparing the sensing voltages and the testing voltages.

[0065] In a preferable embodiment, the bias circuit may provide a first pull-down path and a second pull-down path to ground, and a first pull-up path and a second pull-up path to a supply voltage VTS of the temperature sensor cluster. At one pin of the conversion circuit, two testing voltages are obtain in a case that the pin is grounded through the second pull-down circuit and in a case that the pin is coupled to the supply voltage VTS through the second pull-up circuit. If the testing voltages are close to 0 or the supply voltage VTS, there will be a short-circuit fault that occurs between adjacent pins of the conversion circuit, or an open-circuit fault in the corresponding channel of the temperature sensor cluster 120, or a short-circuit fault in the corresponding channel of the temperature sensor cluster 120. If the testing voltage does not decrease with respect to the sensing voltage, there is an issue in the bias circuit. The failure detection may be verified by comparing the two testing voltages with the sensing voltage for each pin of the conversion circuit.

[0066] In accordance with the embodiments of the present disclosure, such as described above, these embodiments do not describe all the details in detail, nor do they limit the disclosure to the specific embodiments described. Obviously, a lot of modifications and changes can be made based on the above description. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present disclosure, so that those skilled in the art can make good use of the present disclosure and its modifications on the basis of the present disclosure. The present disclosure is limited only by the claims and their full scope and equivalents.

Claims

1.A failure detection system (210) for a temperature sensor cluster (120) which includes a plurality of temperature sensors (NTC1, NTC2, NTC3) to provide multi-channel sensing voltages at a plurality of pins (P1, P2, P3) of a conversion circuit (130), comprising:a bias circuit (211); and a test controller (212) being coupled with the bias circuit (211), and configured to control the bias circuit (211) to selectively pull down and / or pull up voltages at the plurality of pins (P1, P2, P3) to obtain a plurality of testing voltages,wherein the test controller (212) determines faults of the temperature sensor cluster (120) by comparing the sensing voltages and the testing voltages.2.The failure detection system (210) according to claim 1, wherein each channel of the temperature sensor cluster (120) comprises a resistor network of the temperature sensor (NTC1, NTC2, NTC3) that provides a sensing voltage at a node of the resistor network. 3.The failure detection system (210) according to claim 2, wherein the bias circuit (211) is coupled with the plurality of pins (P1, P2, P3) of the conversion circuit (130), or with the resistor networks of the temperature sensors (NTC1, NTC2, NTC3) of the temperature sensor cluster (120).4.The failure detection system (210) according to claim 2, wherein the bias circuit (211) provides at least one of a first pull-down path, a second pull-down path, a first pull-up path, a second pull-up path for each channel of the temperature sensor cluster (120), the first pull-down path pulls down an output of the channel of the temperature sensor cluster (120) directly to a first preset voltage, the second pull-down path pulls down an output of the channel of the temperature sensor cluster (120) through a resistor (Rd1; Rd2; Rd3) to the first preset voltage,the first pull-up path pulls up an output of the channel of the temperature sensor cluster (120) directly to a second preset voltage, andthe second pull-up path pulls up an output of the channel of the temperature sensor cluster (120) through the resistor (Rd1; Rd2; Rd3) to the second preset voltage.5.The failure 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 failure 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 failure detection system (210) according to claim 4, wherein the bias circuit (211) comprises a plurality of switching units (211-1, 211-2, 211-3), each of the plurality of switching units (211-1, 211-2, 211-3) comprising the resistor (Rd1; Rd2; Rd3), and a plurality of switches (S11, S12, S13; S21, S22, S23; S31, S32, S33) are coupled with the resistor (Rd1; Rd2; Rd3) and are operable to change connections between one of the plurality of pins (P1, P2, P3) and one of the first and second preset voltages.8.The failure detection system (210) according to claim 1, wherein the test controller (212) obtains first testing voltages in a case that the bias circuit (211) is activated to pull down the voltages at second pins (P1, P3) of the plurality of pins (P1, P2, P3) directly to a first preset voltage and pull down the voltages at first pins (P2) of the plurality of pins (P1, P2, P3) through resistors (Rd1, Rd2, Rd3) respectively to the first preset voltage, and obtains second testing voltages in a case that the bias circuit (211) is activated to pull down the voltages at the first pins (P2) of the plurality of pins (P1, P2, P3) directly to the first preset voltage and pull down the voltages at the second pins (P1, P3) of the plurality of pins (P1, P2, P3) through resistors (Rd1, Rd2, Rd3) respectively to the first preset voltage; and / orthe test controller (212) obtains third testing voltages in a case that the bias circuit (211) is activated to pull up the voltages at the second pins (P1, P3) of the plurality of pins (P1, P2, P3) directly to a second preset voltage and pull up the voltages at the first pins (P2) of the plurality of pins (P1, P2, P3) through resistors (Rd1, Rd2, Rd3) respectively to the second preset voltage, and obtains fourth testing voltages in a case that the bias circuit (211) is activated to pull up the voltages at the first pins (P2) of the plurality of pins (P1, P2, P3) directly to the second preset voltage and pull up the voltages at the second pins (P1, P3) of the plurality of pins (P1, P2, P3) through resistors (Rd1, Rd2, Rd3) respectively to the second preset voltage.9.The failure detection system (210) according to claim 8, wherein the first pins (P2) of the plurality of pins (P1, P2, P3) are even pins of the conversion circuit (130), and the second pins (P1, P3) of the plurality of pins (P1, P2, P3) are odd pins of the conversion circuit (130).10.The failure detection system (210) according to 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 cluster (120) having a plurality of channels to provide multi-channel sensing voltages, each of the plurality of channels having a temperature sensor; a conversion circuit (130) being coupled with the temperature sensor cluster (120) to convert analog values to digital values of the sensing voltages; anda failure detection system (210) according to any of claims 1 to 10 for detecting faults of the temperature sensor cluster (120) in a test procedure, wherein temperature sensor cluster (120) detects temperatures at various locations near battery cells (BAT1, BAT2, BAT3) of the battery power system.12.A failure detection method for a temperature sensor cluster (120) which includes a plurality of temperature sensors (NTC1, NTC2, NTC3) to provide multi-channel sensing voltages at a plurality of pins (P1, P2, P3) of a conversion circuit (130), comprising: measuring sensing voltages at the plurality of pins (P1, P2, P3); measuring a plurality of testing 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; determining faults of the temperature sensor cluster (120) by comparing the plurality of testing voltages with the sensing voltages.13.The failure detection method according to claim 12, wherein the step of measuring a plurality of testing voltages at the plurality of pins (P1, P2, P3) comprises:measuring first testing voltages at first pins (P2) of the plurality of pins (P1, P2, P3), while second pins (P1, P3) of the plurality of pins (P1, P2, P3) are pulled down directly to the first preset voltage and the first pins (P2) of the plurality of pins (P1, P2, P3) are pulled down to the first preset voltage through resistors (Rd1, Rd2, Rd3), each of the first pins being adjacent to corresponding one of the second pins in the plurality of pins (P1, P2, P3); measuring second testing voltages at the second pins (P1, P3) of the plurality of pins (P1, P2, P3), while the first pins (P2) of the plurality of pins (P1, P2, P3) are pulled down directly to the first preset voltage and the second pins (P1, P3) of the plurality of pins (P1, P2, P3) are pulled down to the first preset voltage through resistors (Rd1, Rd2, Rd3); and / ormeasuring third testing voltages at first pins (P2) of the plurality of pins (P1, P2, P3), while second pins (P1, P3) of the plurality of pins (P1, P2, P3) are pulled up directly to the second preset voltage and the first pins (P2) of the plurality of pins (P1, P2, P3) are pulled up to the second preset voltage through resistors (Rd1, Rd2, Rd3), each of the first pins being adjacent to corresponding one of the second pins in the plurality of pins (P1, P2, P3); measuring fourth testing voltages at the second pins (P1, P3) of the plurality of pins (P1, P2, P3), while the first pins (P2) of the plurality of pins (P1, P2, P3) are pulled up directly to the second preset voltage and the second pins (P1, P3) of the plurality of pins (P1, P2, P3) are pulled up to the second preset voltage through resistors (Rd1, Rd2, Rd3).14.The failure detection method according to claim 13, wherein the first pins (P2) of the plurality of pins (P1, P2, P3) are even pins of the conversion circuit (130), and the second pins (P1, P3) of the plurality of pins (P1, P2, P3) are odd pins of the conversion circuit (130).15.The failure 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 failure 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 each to a supply voltage of the plurality of temperature sensors (NTC1, NTC2, NTC3).

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