阅读说明：本技术 用于检测何时超过预定义温度阈值的方法和装置 (Method and apparatus for detecting when a predefined temperature threshold is exceeded ) 是由 N·拉特 A·艾特埃尔巴查 A·多克特 于 2019-02-05 设计创作，主要内容包括：一种用于检测至少一个热源何时超过温度阈值的装置和方法,所述装置包括：部件,该部件的电阻根据该部件的工作温度而变化；以及电源,该电源适合于向该部件供应电流。该部件可以热耦合到该热源,使得该工作温度根据该热源的温度和由于焦耳效应而在该部件中释放出的热量而变化,如果该工作温度大于触发阈值,则该可变电阻具有高值,该电源被配置为生成该电流,使得一旦该热源的温度大于或等于该温度阈值,该工作温度就大于或等于该触发阈值,进而该可变电阻具有该高值。该电源是电流源,并且该电流以具有固定占空比或可变占空比的周期性脉冲的形式被供应。(An apparatus and method for detecting when at least one heat source exceeds a temperature threshold, the apparatus comprising: a component, the resistance of which varies according to the operating temperature of the component; and a power supply adapted to supply current to the component. The component may be thermally coupled to the heat source such that the operating temperature varies as a function of the temperature of the heat source and the amount of heat released in the component due to joule effect, the variable resistance having a high value if the operating temperature is greater than a trigger threshold, the power source being configured to generate the current such that the operating temperature is greater than or equal to the trigger threshold once the temperature of the heat source is greater than or equal to the temperature threshold, and the variable resistance having the high value. The power source is a current source and the current is supplied in the form of periodic pulses with a fixed duty cycle or a variable duty cycle.)

1. A device (D) for detecting that at least one heat source (S) exceeds a first predefined Threshold (TS) of temperature (T), the detection device (D) comprising:

-at least one component (C1, C2, Ci, Ck), the resistance of which is variable according to the operating temperature of the component (C1, C2, Ci, Ck),

-a power supply capable of delivering a current (Is) flowing through said components (C1, C2, Ci, Ck),

the component (C1, C2, Ci, Ck) can be thermally coupled to the heat source (S) such that the operating temperature (Tf) varies according to:

-the temperature (T) of the heat source (S), and

-the heat released due to Joule heating in the component when the current (Is) flows through the component (C1, C2, Ci, Ck),

if the operating temperature (Tf) is higher than a second predefined temperature threshold, called trip threshold (Td), the variable resistance has a high value (Rd),

the power supply Is configured to generate the current (Is) such that the operating temperature (Tf) Is higher than or equal to the trip threshold (Td) when the temperature (T) of said heat source (S) Is higher than or equal to the first predefined temperature Threshold (TS), the variable resistance then having the high value (Rd),

wherein the power supply Is a current source, and wherein the current (Is) Is delivered in the form of periodic pulses having a fixed duty cycle or a variable duty cycle.

2. The device (D) according to the preceding claim, wherein the device (D) is electrically isolated from the heat source (S).

3. An apparatus (D) as claimed in any one of the preceding claims, characterized in that it is configured to detect that one of a plurality of heat sources (S1, S2, Sj, Sn) exceeds the first temperature Threshold (TS), and in that it comprises a plurality of components (C1, C2, Ci, Ck) in the form of self-healing fuses, each self-healing fuse (C1, C2, Ci, Ck) being thermally coupled to at least one heat source (S1, S2, Sj), the fuses (C1, C2, Ck) being connected in series.

4. The device (D) according to the preceding claim, further comprising: a plurality of resistors (R1, R2, Ri, Rk) each having a different resistance, one resistor connected in parallel across each fuse (C1, C2, Ci, Ck).

5. The device (D) of any one of the preceding claims, wherein the at least one heat source is a battery cell of a battery.

6. The apparatus of any one of the preceding claims, further comprising: a monitoring module (M) configured to trigger a corrective action or a marking action when the variable resistance of one of said components (C1, C2, Ci, Ck) has this high value (Rd).

7. A method for monitoring at least one heat source (S, S1, Si, Sk, Sn) exceeding a first Threshold (TS) of temperature (T), the method being performed by a detection device (D) comprising:

-at least one component (C1, C2, Ci, Ck) whose resistance can be varied as a function of an operating temperature (Tf) of the component, the variable resistance having a high value (Rd) if the operating temperature (Tf) is higher than a second predefined temperature threshold called trip threshold (Td),

-a power supply capable of delivering a current (Is) flowing through said component (C1, C2, Ci, Ck), the method comprising:

-a step (E10) of thermally coupling the at least one heat source (S, S1, Si, Sk, Sn) to the at least one component (C1, C2, Ci, Ck) so that the operating temperature (Tf) varies according to:

o the temperature (T) of the heat source (S), and

o the heat released as a result of joule heating in the component when the current (Is) flows through the component (C1, C2, Ci, Ck),

-a step (E20) of connecting the power supply (E) to the at least one component (C1, C2, Ci, Ck);

-a step (E30) of configuring the power supply to generate the current (Is) such that the operating temperature (Tf) Is higher than or equal to the trip threshold (Td) when the temperature (T) of said heat source (S) Is higher than or equal to the first predefined temperature Threshold (TS), the variable resistance then having the high value (Rd),

wherein the power supply Is a current source, and wherein the current (Is) Is delivered in the form of periodic pulses having a fixed duty cycle or a variable duty cycle.

8. The monitoring method of the preceding claim, wherein the detection device (D) comprises:

a plurality of components (Cj) connected in series and each having a resistance variable according to a respective operating temperature (Tfj),

a plurality of resistors (Rj) having different resistances, one resistor being connected in parallel across both ends of each component (Cj) such that, when the resistance of a component (Ck) has the high value (Rd), the equivalent resistance (Re) of the electrical chain formed by the components (Cj) and the resistors (Rj) has a different value for each component (Ck) and the resistors (Rk) connected in parallel with the component, and wherein,

-thermally coupling each component (Cj) to at least one heat source (Si, Sk) during the thermal coupling step (E10),

-connecting the power supply (E) to the electrical chain formed by the components (Cj) and the resistors (Rj) during the connecting step (E20),

the method further comprises the following steps:

a step (E30) of generating a supply signal (I) with the power supply (E),

-a step (E40) of detecting a response signal (u) across the two terminals of the power supply (E),

-a step (E50) of determining the equivalent resistance (Re) of the electrical chain formed by the components (Cj) and the resistors (Rj);

-a step (E60) of identifying, from the equivalent resistance (Re), the component (Ck) whose resistance has the high value (Rd).

9. The monitoring method of any one of claims 7 and 8, wherein the configuring step (E30) comprises a sub-step (E32) of determining a dimension of the detection device (D), the sub-step comprising determining a first duty cycle of periodic current pulses according to:

-a first temperature Threshold (TS) to be monitored,

-an electrical characteristic of the at least one component (C1, C2, Ci, Ck), and

-a property of thermal coupling between the at least one heat source (S) and the at least one component (C1, C2, Ci, Ck).

10. The monitoring method of the preceding claim, wherein, after the first detection of exceeding the first temperature Threshold (TS), the configuring step (E30) further comprises:

-a sub-step (E34) of emitting current pulses having a second duty cycle smaller than the first duty cycle;

-a sub-step (E36) of confirming the detection of the first overtake detection.

11. Vehicle (V) comprising a device (D) for detecting exceeding of a predefined temperature Threshold (TS) according to one of claims 1 to 6.

Technical Field

The present invention relates to a device for monitoring the temperature of a heat source, and more particularly to a monitoring device comprising an electronic component whose electrical resistance is variable with operating temperature.

Background

The present invention proposes a device for detecting the exceeding of the temperature of one or more heat sources, allowing the adjustment of the monitored temperature threshold.

From document CN 102195270, a device for monitoring the temperature of a plurality of heat sources constituted by battery cells of a battery is known. The device includes a plate whose volume is variable with temperature. The plate is placed against the cell wall to be monitored. In the event of overheating, the plate expands and mechanically actuates a switch placed facing said plate, the opening of which interrupts the passage of the charging current through the battery cell.

However, in this solution, there is only one parameter for adjusting the overheating temperature threshold, i.e. the distance between the plate and the switch; thus, this parameter is only adjustable during the manufacture of the module comprising one or more battery cells to be monitored, and is not changeable thereafter. After manufacturing is complete, the monitored temperature threshold cannot be adjusted any more. In addition, a sudden disconnection of the battery cells can result, and therefore no other corrective measures can be envisaged.

Accordingly, there is a need for a device for monitoring the temperature of one or more heat sources that allows for adjustment of the monitored temperature threshold.

To this end, the invention aims to provide a device for detecting that at least one heat source exceeds a first predefined threshold value of temperature, the detection device comprising:

at least one component, the electrical resistance of which can be varied as a function of the operating temperature of the component,

-a power source capable of delivering a current through said component,

the component is thermally coupleable to the heat source such that the operating temperature (Tf) varies according to:

-the temperature of the heat source, and

-the heat released due to Joule heating in the component when the current flows through the component,

if the operating temperature is above a second predefined temperature threshold, called trip threshold, the variable resistance has a high value,

the power supply is configured to generate the current such that the operating temperature is greater than or equal to the trip threshold when the temperature of the heat source is greater than or equal to the first predefined temperature threshold, whereby the variable resistance has the high value,

wherein the power source is a current source, and wherein the current is delivered in the form of periodic pulses having a fixed duty cycle or a variable duty cycle.

In a preferred embodiment, the device according to the invention can advantageously have the following features, alone or in combination:

the device may be electrically isolated from the heat source,

the apparatus may be configured to detect that a heat source of a plurality of heat sources exceeds the first temperature threshold, and the apparatus may comprise a plurality of components in the form of a plurality of self-healing fuses, each self-healing fuse being thermally coupled to at least one heat source, the fuses being connected in series,

the apparatus may further comprise a plurality of resistors, which may each have a different resistance, one resistor may be connected in parallel across both ends of each fuse,

the at least one heat source may be a battery cell of a battery,

the device may further comprise a monitoring module configured to trigger a corrective action or a marking action when the variable resistance of one of said components has the high value.

Another subject of the invention is a method for monitoring at least one heat source exceeding a first threshold value of temperature, the method being performed by a detection device (D) comprising:

-at least one component, the resistance of which is variable according to the operating temperature of the component, the variable resistance having a high value if the operating temperature is higher than a second predefined temperature threshold, called trip threshold,

-a power source capable of delivering a current through said component,

the method comprises the following steps:

-a step of thermally coupling the at least one heat source to the at least one component such that the operating temperature varies according to:

■ temperature of the heat source, and

■ due to the heat released by joule heating in the member when the current flows through the member,

-a step of connecting the power source to the at least one component;

-a step of configuring the power supply to generate the current such that the operating temperature is higher than or equal to the trip threshold when the temperature of said heat source is higher than or equal to the first predefined temperature threshold, the variable resistance then having the high value,

wherein the power source is a current source, and wherein the current is delivered in the form of periodic pulses having a fixed duty cycle or a variable duty cycle.

In a preferred embodiment, the method according to the invention may advantageously have the following features, alone or in combination, as long as the detection means are able to comprise:

a plurality of components connected in series and each having an electrical resistance variable according to a respective operating temperature, an

A plurality of resistors having different resistances, one resistor being connected in parallel across both ends of each component, such that when the resistance of a component has the high value, the equivalent resistance of the electrical chain formed by the components and the resistors has a different value for each component and the resistor connected in parallel with the component,

the method may then include:

-thermally coupling each component to at least one heat source during the thermally coupling step,

-connecting the power source to the electrical chain formed by the components and the resistors during the connecting step,

the method may then further comprise:

-a step of generating a supply signal with the power supply,

-a step of detecting a response signal across the terminals of the power supply,

-a step of determining the equivalent resistance of the electrical chain formed by the components and the resistors;

-a step of identifying the component whose resistance has the high value on the basis of the equivalent resistance.

The configuring step may then comprise a sub-step of determining a dimension of the detection means, the sub-step comprising determining a first duty cycle of the periodic current pulses in dependence on:

-a first temperature threshold to be monitored,

-an electrical characteristic of the at least one component, and

-a property of a thermal coupling between the at least one heat source and the at least one component.

After the first detection of exceeding the first temperature threshold, the configuring step may further include:

-a sub-step of transmitting current pulses having a second duty cycle smaller than the first duty cycle;

-a sub-step of confirming the detection of the first time overrun detection.

Another subject of the invention relates to a vehicle comprising a device for detecting a temperature overshoot as described above.

Drawings

Fig. 1 and 2 schematically show two embodiments of a device for detecting temperature overshoots, which is arranged to monitor the respective temperatures of battery cells of a plurality of batteries.

Fig. 3 and 4 show two devices for detecting temperature overshoots according to two embodiments of the invention.

Fig. 5 shows the steps of a method for identifying heat sources that have exceeded a predefined temperature threshold according to an embodiment of the invention.

Detailed Description

Fig. 1 schematically shows a detection apparatus according to an embodiment of the present invention. The device D is installed in the vehicle V to monitor the temperature of a plurality of heat sources S1, S2, Sj, … …, Sn constituted by battery cells grouped into batteries in modules M1, … …, Mm. The cells of these batteries are soft-shelled cells.

The device comprises a plurality of components C1, C2, Ci, Ck, the resistances R _ PTC of which can vary according to the operating temperatures Tf of the components C1, C2, Ci, Ck. In a preferred embodiment, the components C1, C2, Ci, Ck take the form of a plurality of self-healing fuses.

Each self-healing fuse C1, C2, Ci, Ck is thermally coupled to at least one heat source S1, S2, Sj, Sn. In the example illustrated in fig. 1, the heat source is a battery cell of a battery, and the thermal coupling is achieved by: each self-healing fuse C1, C2, Ci, Ck is coated with a thermal coating, which is then secured in contact with the cells of the battery. Each self-healing fuse C1, C2, Ci, Ck is coupled to a cell of two batteries, the coating being secured by adhesive bonding and/or compression.

The device also comprises a power supply E capable of delivering a current Is flowing through self-healing fuses C1, C2, Ci, Ck, which are thermally coupled to the battery cells S1, S2, Sj, Sn of the battery, and therefore the respective operating temperatures of the components C1, C2, Ci, Ck vary according to:

-the temperature T of one or more heat sources S to which the component is thermally coupled, and

the heat released due to joule heating in the components when the current Is flows through the components C1, C2, Ci, Ck.

The variable resistance of the component (in this example a self-healing fuse) has a high value Rd if the operating temperature Tf of the component is higher than a second predefined temperature threshold, called trip threshold Td.

The power supply Is configured to generate a current Is such that the operating temperature Tf Is higher than or equal to the trip threshold Td when the temperature T of said heat source S Is higher than or equal to a first predefined temperature threshold TS, the variable resistance in turn having a high value Rd.

Device D is electrically isolated from heat source S. In this way, the operating characteristics of the detection device D are independent of the electrical characteristics of the heat source to be monitored: for a voltage delivered by the power source E of typically 12V, the value of the current Is flowing through the self-healing fuse varies between 100mA and 800mA, whereas the operating voltage delivered jointly by the cells of all the batteries considered Is typically 400V.

In the illustrated example, the power source E is a current source and the components C1, C2, Ci, Ck are connected in series. In this way, the current Is not dependent on the number k of components of the device D nor on the number n of heat sources to be monitored, which simplifies the adjustment of the first temperature threshold TS. The first temperature threshold TS can be increased simply by reducing the current Is delivered by the current source E and vice versa.

As already mentioned, the operating temperature of the component (in this example, a self-healing fuse) depends on the temperature T of the heat source S to which the component Is thermally coupled, and the amount of heat generated due to joule heating in the component when a current Is flows through the component. Thus, for a component characterized by a given trip temperature threshold Td, the first temperature threshold TS of the monitored heat sources S1, S2, Sj, Sn may be adjusted by varying the amount of heat generated due to joule heating in the component.

In a preferred embodiment, the current Is delivered in the form of periodic pulses with a fixed duty cycle or a variable duty cycle.

Thus, the amount of heat generated due to joule heating in the component can be adjusted by modifying the time during which the current flows through the component, which can be achieved simply by changing the duty cycle of the periodic pulses.

Fig. 3 illustrates one embodiment of a detection device incorporating a power source E configured to deliver a current Is in the form of an electrical pulse.

In the phase E32 of determining the dimensions of the detection device D, a fixed duty cycle may be defined for each application, according to the first temperature threshold TS to be monitored, the electrical characteristics of the components C1, C2, Ci, Ck, and the characteristics of the thermal coupling between the heat source to be monitored and these components. This duty cycle, and therefore the first temperature threshold TS to be monitored, can therefore be adjusted according to the specificity of each application.

The ability to vary the duty cycle during the utilization phase of the detection device D allows the first temperature threshold TS to be varied without having to vary the manner in which the device D is installed or the manner in which it is thermally coupled to a heat source.

A one-time change of the duty cycle after the first detection exceeding the first temperature threshold TS allows to confirm this first detection in phase E36 and thus allows to improve the reliability of the detection result by emitting pulses with a lower duty cycle in phase E34.

In a preferred embodiment, the detection device D further comprises a monitoring module M configured to trigger a corrective action or a marking action when the variable resistance of one of said components C1, C2, Ci, Cn has a high value Rd. This module M is configured to detect a variation in the resistance value of the component Ci, for example by measuring the voltage across the power supply and/or measuring the current at the terminals of the power supply.

Next, the monitoring module M may trigger a cooling action, which will result in a decrease of the temperature of the heat source and the components C1, C2, Ci, Cn. This configuration is particularly advantageous in the case where the detection device D is equipped with components C1, C2, Ci, Cn in the form of self-healing fuses. Specifically, once the operating temperature drops, the variable resistance of this type of component returns to a low value (referred to as the holding resistance Rm), which causes the process of monitoring the temperature of the heat source to begin again.

In a preferred embodiment, as illustrated in fig. 2, the device D also comprises a plurality of resistors R1, R2, Ri, Rk, each having a different resistance, one resistor being connected in parallel across each component C1, C2, Ci, Ck.

As will be explained below, this arrangement allows to identify a self-healing fuse Ci (which is thermally coupled to one heat source Sj, in this example a battery cell) which has exceeded a first temperature threshold TS. Thus, a cooling strategy for a particular heat source may be implemented.

Such detection means D may be configured to identify, among the plurality of heat sources S1, S2, Sj, Sn, a heat source Sj that has exceeded a first predefined temperature threshold TS. The device D comprises a plurality of components C1, C2, Ci, Ck connected in series and having respective resistances variable according to the respective operating temperatures, the variable resistance having a high value Rd (called trip resistance) if the operating temperature Tfj is higher than a second predefined temperature threshold (called trip threshold Td) and a low value Rm (called holding resistance) in the opposite case.

It should be noted that, according to an embodiment, the holding resistance Rm of the components C1, C2, Ci, Ck may correspond to a value close to 0 Ω and the tripping resistance Rd corresponds to an open circuit; this is the case for components such as fuses or on/off switches.

In the embodiment using the self-healing fuse, the holding resistance Rm is typically a resistance of 0 Ω, and the trip resistance Rd is typically a resistance of several k Ω.

In any case, the value of the holding resistance Rm is negligible with respect to the value of the tripping resistance Rd, so that Rd + (k-1) × Rm ≈ Rd, k being the number of components of the detection device D. The use of this feature will be explained below.

Each component C1, C2, Ci, Ck can be thermally coupled to at least one of the heat sources S1, S2, Sj, Sn, so that the operating temperature of the component is higher than or equal to the trip threshold Td when the temperature of said at least one heat source Si, Sk, Sn is higher than or equal to the first predefined temperature threshold TS, and the variable resistance has a high value Rd.

The device D also comprises a plurality of resistors R1, R2, Ri, Rk having different resistances, one resistor being connected in parallel across the two ends of each component C1, C2, Ci, Ck, so that when the resistance of the component Ci has a high value Rd, the equivalent resistance Re of the electrical chain formed by the component C1, C2, Ci, Ck and the resistors R1, R2, Ri, Rk is the characteristic value of this component (Ck) and the resistor Ri connected in parallel to it.

Alternatively, the resistor Ri may be connected in parallel to a set of components Ci-1, Ci +1, which are connected in series and each coupled to at least one respective heat source. This arrangement is particularly advantageous when the heat sources are grouped. An example of an application of this embodiment of the invention is to monitor the temperature of the cells of soft-shelled batteries grouped into battery modules M1, M2, … …, Mm, as illustrated in fig. 4. If one of the cells Sj of the monitored battery exceeds a first predefined temperature threshold TS, the component Ci thermally coupled to this cell Sj will have a high resistance Rd. If the other cells in the battery do not exceed the first temperature threshold TS, the set of components connected in series will have an equivalent resistance Rd + (k-1) × Rm, k being the number of components connected in series; these resistances connected in parallel to the resistor Ri will have in common an equivalent resistance

Re＝Ri*[Rd+(k-1)*Rm]/[Ri+Rd+(k-1)*Rm]。

The component Ci and the resistor Ri are chosen such that:

1) the value of the resistance Rm is negligible with respect to the value of Rd, i.e. such that:

Rd+(k-1)*Rm≈Rd。

therefore, since:

Re＝Ri*[Rd+(k-1)*Rm]/[Ri+Rd+(k-1)*Rm]，

its value is substantially equal to:

Re≈Ri*Rd/(Ri+Rd)。

2) ri is negligible with respect to Rd, and therefore:

Ri*Rd/(Ri+Rd)≈Ri。

thus, the equivalent resistance Re of the resistor Ri connected in parallel to Ri is substantially equal to Ri: a component Ci thermally coupled to a cell Sj of a battery that has exceeded a first temperature threshold TS; or a group of components Ci-1, Ci +1, connected in series and one of which is thermally coupled to a cell Sj of a battery which has exceeded the first temperature threshold TS. By judiciously choosing different resistances for the resistors R1, R2, … …, Ri, Rk, the equivalent resistance of the electrical chain in question can be made to exhibit the following characteristic values:

a component Ci thermally coupled to a battery cell Sj of a battery that has exceeded a first temperature threshold TS, or

A set of components Ci-1, Ci +1, which are connected in series and of which one component Ci thermally coupled to a cell Sk of one battery has exceeded a first temperature threshold TS,

and a resistor Ri connected in parallel with the component or group of components.

A method for identifying a heat source Sj, among a plurality of heat sources S1, S2, Sj, Sn, which has exceeded a first predefined threshold TS of temperature T will now be described with reference to fig. 5.

The method may be implemented using a detection device such as described above, i.e. using a detection device comprising: a plurality of components C1, C2, Ci, Ck, which are able to have a low value (called holding resistance Rm) or a high value (called tripping resistance Rd) depending on their operating temperature; and a plurality of resistors R1, R2, Ri, Rk, having different resistances, and connected in parallel to one component Ci or a group of components Ci-1, Ci +1 connected in series.

The method comprises the following steps:

a step E10 of thermally coupling a plurality of heat sources S1, S2, Sj, Sn to a component C1, C2, Ci, Ck, each component being thermally coupled to at least one heat source Si such that the operating temperature of the component is higher than or equal to a trip threshold Td when the temperature of said at least one heat source is higher than or equal to a first predefined temperature threshold TS, the variable resistance of the component in turn having a high value Rd,

a step E20 of connecting the electric chain formed by the components C1, C2, Ci, Ck and the resistors R1, R2, Ri, Rk to the power supply E,

a step E30 of generating a supply signal U, I with the power supply E,

a step E40 of detecting the response signals i, u across the supply E,

a step E50 of determining the equivalent resistance Re of the electrical chain formed by the components C1, C2, Ci, Ck and the resistors R1, R2, Ri, Rk;

a step E60 of identifying, from the equivalent resistance Re, the component Ci whose resistance has a high value Rd.

In the illustrated example, the supply signal generated in the generating step E30 Is a current Is, and the response signal detected in the detecting step E40 Is a voltage across the current source E.

Since the value of the generated current Is and the value of the detected voltage are known, the equivalent resistance Re of the electrical chain Is determined during the execution of the determination step E50. As explained above, this equivalent resistance is a characteristic of a component Ci or a group of components, one of which has a high resistance value Rd, and a resistor Ri connected to the component or group of components. This allows this component Ci to be identified in an identification step E60.

Of course, the invention is not limited to the examples and embodiments described and shown. Rather, many variations of the invention may be made which are within the ability of those skilled in the art.

For example, other arrangements are possible depending on the configuration of the heat source. In particular, the invention can be applied to monitoring the area of the heat source under the following conditions: a grid is formed covering the area to be monitored and components (such as those described) thermally coupled to the area to be monitored are placed at nodes of the grid.