DE102017001054A1 - Measuring arrangement and method for spatially resolved multiple temperature measurement along a path. - Google Patents

Abstract

The invention relates to a method and a corresponding measuring arrangement (10) for spatially resolved multiple temperature determination in the close environment along a plurality of electrical lines (14a-d). By means of a combined signal transceiver (11), according to the method, a signal (H) is driven into a signal cable harness (12). The signal passing from the signal transceiver causes a return signal (R). The combined signal transceiver picks up the temporal voltage curve of the resulting mixed signal. From the signal shape of the mixed signal can be closed due to additionally occurring reflections on temperature events along the signal wiring harness. The mixed signal in the signal transceiver is then analyzed by the method relating to the invention in such a way that an information matrix is made available by telecommunications which consists of a plurality of temperature values (T) and the respectively associated local values (O).

Description

The invention relates to a method together with associated measuring arrangement for cost-effective temperature detection, as well as temperature localization of the measuring arrangement surrounding parts of a system (13). The measuring arrangement includes a combined signal transceiver (11) which is connected on one side to a signal wiring harness (12), which is also part of the measuring arrangement, preferably via plug-in contacts on its supply side and serves as a signal generator, signal value sensor and signal analyzer. Furthermore, the invention relates to a method for determining temperature events (13) along the signal line (14a-d), or the signal wiring harness (12). The design of the measuring arrangement is chosen in particular such that at the signal line end, opposite to the signal transceiver (11), apart from open terminals, components for secondary use are preferably additionally connected, which in nature and size can have any, also temporally variable impedances (15). For example, energy storage cells, solar cells, electric motor windings are mentioned.

Background.

Complex electrical systems are more than ever entitled to operational safety with regard to increasing automation and autonomization. This leads to the direct desire for the best possible monitoring of all operating parameters of a particular system. For example, modern battery packaging systems, such as those for the automotive or aerospace industry, have installed a large number of energy storage cells which, by means of monitoring electronics, must determine the current state and trend of the state change of the system. In the cited example, this basically takes place by means of a combination of voltage and current sensor systems, which are electrically connected directly to the individual elements via sensor lines, each consisting of metal conductor and insulation. However, in the highest instance, condition monitoring is done by temperature measurement and evaluation. From "Challenges in Battery Pack Design," written by S. Rothgang, H. Nordmann, C. Schäper, D.U. Sauer, published in "2012 Electrical Systems for Aircraft, Railway and Ship Propulsion, Bologna, 2012, p. 1-6 ", it is well-known that battery pack systems generally have installed very few, dedicated temperature sensors for cost reasons, but in contrast to that usually a high recognition rate is required. Due to the complexity of these systems, many production steps are necessary. The higher the associated risk of manufacturing errors. At the same time errors during operation are not completely excludable. Therefore, the urge for early detection is very large. However, an early detection in extent and location is inevitably only incompletely possible with a few dedicated temperature sensors. Apart from complex battery systems, the person skilled in the art recognizes that the problem of the exact temperature measurements, which are as frequent as possible in terms of number and detection rate, does not exclusively depend on the battery pack systems but can also be found in any other complex systems that are not restricted to electrical engineering.

State of the art.

1. (a) Off WO 2009/115127 A1 , such as US 5,185,594 A For example, a device is known which uses a measuring arrangement which, as an insulating material, places a material between two signal conductors which has a thermal dependence in its resistive conductivity. In this case, this is carried out in such a way that the material in question locally localized, rising temperature assumes a corresponding, locally larger conductance, whereby the measuring circuit by means of signal pulse evaluation locate a simply occurring Temperaturevent on the signal propagation time and then measure the conductance based on the impressed current and voltage amplitude and then can determine the temperature.
2. (b) Off DE10 2013 227 051 A1 a measuring device for the determination of spatially resolved temperatures in parts is fundamentally known. The aforementioned publication shows a measuring arrangement, consisting of a sensor cable with at least two poles, whose material properties are so pronounced that it is possible to locate a single temperature event along the sensor cable with the aid of a signal generator, two dedicated evaluation units and a separate, resistive temperature sensor Temperature to determine. It is stated that the effect to be exploited lies in the temperature dependence of the dielectric of the insulation material of the signal conductor. The additionally built-in, resistive temperature sensor, which is designed as a resistance wire with a high temperature gradient with respect to its ohmic resistance, is used there to be able to detect a uniform temperature change over the entire sensor cable. DE10 2013 227 051 A1 further implies that the line impedance of the signal line changes as the dielectric constant changes due to temperature variations, which is generally known about material properties is. This local change in the line impedance can be determined by means of the time domain reflectometry due to differences in propagation time of the signal reflection in the evaluation units. In DE10 2013 227 051 A1 alone the amplitude and only the duration of the reflection is evaluated.
3. (c) Off WO 2009/046751 A1 It is known that coaxial conductors can be used as temperature sensors in order to be able to reproduce temperatures and, supposedly, their distributions in the same as well as in the direct vicinity of same. For this purpose, the known method of the time domain reflectometry already mentioned under (b) is used to evaluate signal scatters on thermally induced line impedance changes. The method used uses an analysis of the amplitude differences of various voltage signals, which can be converted due to their temporal occurrence in a temperature change, as well as in a location. The amplitude changes are given as about 2 mV per 20 K temperature difference. Examples of typical applications include the monitoring of power transmission cables, as well as electric motor windings and transformers.

In the WO 2009/115127 A1 , as well as in US 5,185,594 A cited measuring arrangements are not suitable for cost-sensitive applications due to the elaborate production of the insulation material and the exclusive use as a temperature sensor. Moreover, their major drawback is the variable conductance along two mated signal conductors, which makes them limited for high-level voltage signals that must be operated isolated from each other, in direct contrast to the cost-minimized secondary use of an overall system.

In the DE10 2013 227 051 A1 These methods and measuring arrangements are not able to detect multiple temperature events on the line due to their simple evaluation of an amplitude signal, which is formed according to switching from a differential delay difference. Moreover, due to the arrangement of the measuring mechanism and the complex configuration of the special cable necessary for the optimal use of the method, it is not possible to give the system designed in this way a secondary benefit which contributes to maximized cost efficiency.

This in WO 2009/046751 A1 cited method and measuring arrangement is not able to reproduce exact temperatures due to the sole utilization of the temporally and thus locally resolved voltage amplitude comparison, since the method does not analyze the waveform, but, as already in DE10 2013 227 051 A1 called, uses only the signal amplitude for evaluation. Moreover, a signal amplitude considered there alone can not say anything about a temperature distribution, since at least two reflections occur within a temperature disturbance (at the beginning and end of the temperature event), which causes a part of the continuous signal to be reflected at both reflection points until its amplitude is zero Volt reached. The measured superimposition of these partial reflections can now be as in WO 2009/046751 A1 However, these overlaps may not be physically dependent on different high temperature points within a cable area.

On this basis, the object of the invention to provide a measuring arrangement, as well as an associated method for the evaluation of multiple temperature events along a path, which allows its flexibility of the measuring arrangement to be used to give a cost-optimizing secondary benefits for the measuring arrangement, at the same time by a novel Utilizing a physical phenomenon reduces the complexity of previous measurement arrangements, and primarily achieves an increase in measurement accuracy and, closely linked with it, also the recognition rate and precision should be maximized.

The object is achieved by a measuring arrangement for spatially resolved multiple temperature measurement with the features of claim 1. The measuring arrangement comprises a signal transceiver which, according to a method as claimed in claims 4, 5, 6, 7, drives a signal into the feed point at the starting point of the signal wiring harness. The signal cable harness consists of a plurality of signal lines, which are preferably stranded at least in pairs. The signal lines are each enveloped by at least one insulation layer, which preferably has a high thermal dependency on its dielectric constant. The signal transceiver has in addition to the driving of the measuring pulse, the task of detecting all in the signal lines caused by local hot spots signal changes, store and output evaluating as locally resolved temperature information. In addition, the measuring arrangement comprises at the sensor cable harness end opposite the feed-in point a mimic which consists of any desired combination of preferably electrical elements of any impedance.

It is assumed that the measuring arrangement contributes a measured reference curve has stored known temperature distribution along the signal wiring harness for calibration.

With this measuring arrangement, the change in the dielectric constant of a covering insulating material of a conductor is utilized. As a result of a localized heat impact this leads to a local change in the line impedance, which is localized. In general, it is known from the field of conduction theory that a reflection factor for propagating waves develops in the case of a preferably abrupt change in the line impedance, which splits a signal traveling to the thermal defect into a signal transmitted and returned with respect to the defect.

This effect now leads to a mixed signal, which consists of a sum of a running and returning signal, which can be used according to the local limitation of the thermal impurity to a value by means of a mathematical integral formation of the difference determination of the voltage normalized reference curve with the disturbed mixed signal curve to calculate, which is directly proportional to the thermal change of the local dielectric constant and thus a change of the local capacitance.

The said mixed signal, in the presence of a local thermal defect, consists of a clearly separable from the reference curve signal deflection, which consists of the change of the impurity impedance at the start of the defect, as well as a new change in signal passage of the end of the defect.

From a known phase velocity within a signal wiring harness, the location of the associated temperature event can now be calculated from the time information when the mixing signal is deflected.

This property is expediently exploited according to the invention in order to determine further thermal impurities in location, distribution and temperature along the path.

A person skilled in the art will recognize that the number of defects that can be identified in principle is not limited.

In order to achieve a high sensitivity, the signal transceiver is designed such that it can drive signals to be injected at a signal rise rate of at least 100 V / μs and preferably 400 V / μs, and has a Meßgranularität of at least 1 mV and preferably 250 uV, and a Time base resolution for the mixed signal of 10 ps and preferably 1 ps has.

In principle, in the case of a geometrically homogeneous temperature change along the signal wiring harness in the absence of local line impedance changes, the measuring arrangement can not measure a mixed signal with locally limited amplitude changes. Instead, the overall level of the mixed signal is then additionally compared with that of the reference signal, since, given a constant electrical line adaptation of the signal transceiver, this results in a measurable value which correlates directly with the temperature change that causes it.

Advantageously, the invention made has an effect on the increased number of determinable temperature events along one or more signal lines, which also achieve the recognition precision in temperature and location by utilizing the novel evaluations. At the same time, the use of standard harnesses has a strong advantage over the prior art in terms of the economic aspect of the application.

• 1 Eine grob vereinfachte Darstellung der Messanordnung.
• 2 Eine grob vereinfachte Darstellung der Messanordnung mit beispielhafter Erweiterung gemäß Anspruch 8.
• 3 Eine perspektivische Darstellung des Querschnittes durch eine einzelne Sensorleitung.
• 4 Einen auf relevante Teile des Signalverlaufs beschränkten, sowie vereinfachenden Ausschnitt, der Mischsignale für verschiedene Betriebsszenarien.
• 5 Einen auf relevante Teile des Signalverlaufs beschränkten, sowie vereinfachenden Ausschnitt, der das Mischsignal für einen Spezialfall fokussiert.
• 6 Eine beispielhafte, vereinfachte Darstellung eines Messergebnisses.
• 7 Eine Darstellung des Zusammenhangs der lokalen Kapazität bzgl. der Temperatur.

The embodiments of the invention will be explained in more detail with reference to FIGS. These show partly in highly simplified representations:

• 1 A rough simplified representation of the measuring arrangement.
• 2 A rough simplified representation of the measuring arrangement with exemplary extension according to claim 8.
• 3 A perspective view of the cross section through a single sensor line.
• 4 A section limited to relevant parts of the signal waveform, as well as simplifying section, the mixed signals for different operating scenarios.
• 5 A section that is limited to relevant parts of the signal as well as simplifying section, which focuses the mixed signal for a special case.
• 6 An exemplary, simplified representation of a measurement result.
• 7 A representation of the relationship of the local capacity with respect to the temperature.

In the figures, like-acting parts are represented by the same reference numerals.

An in 1 illustrated measuring arrangement ( 10 ) for the spatially resolved temperature measurement of multiple temperature events ( 13 ) comprises four signal lines (14a), (14b), (14c), (14d) as a subset of a plurality of signal lines, each with an insulating material of temperature-dependent dielectric constant ( 31 ) are enveloped (cf. 3 ). The signal lines are combined, preferably in pairs, as a signal wiring harness ( 12 ). Connected to the signal wiring harness is a signal transceiver unit ( 11 ), as well as on the other hand a mimic ( 15 ), which may include any number of electrical components of any impedance preferably complementary. On the signal wiring harness ( 12 ) act in an application example local temperature events ( 13 ), which by the signal transceiver ( 11 ) fed signals ( H ) locally and as a reflected partial signal ( R ) the signal transceiver ( 11 ). This gives the evaluated signals in the form of places ( O ) and associated temperatures ( T ) out.

At signal ( H ) is preferably a digital, time-limited jump signal, which is fed at high slew rate.

At the in 2 illustrated embodiment variant ( 20 ) the person skilled in the art will recognize a preferred embodiment of a signal cable tree (but not limited in form) ( 12 ) to handle a larger number of local temperature events ( 13 ) to be able to measure more flexibly at locally remote locations. The further details of the embodiment ( 20 ) coincide equally with those in 1 described details.

An in 3 illustrated cross-sectional view ( 30 ) shows the typical configuration of a signal conductor (14a), (14b), (14c), (14d), which expediently consists of a homogeneous, highly conductive material of thin cross-section, which with a close-fitting envelope of an insulating material of thermal, preferably strong , Dependent dielectric constant is occupied.

In the 4 illustrated graphic ( 40 ) shows three mixed signals ( 41 ) 42 ) 43 ), which are slightly shifted relative to each other for better readability, but each time ( 44 ) and the signal amplitude ( 48 ) to have. Mixed signal ( 41 ) represents as a solid line the reference for a measurement with a homogeneous local temperature distribution known temperature, wherein the curve between starting point ( 44 ) and endpoint ( 45 ) a signal plateau at level ( 48 ) Has. The other curves ( 42 ) and ( 43 ) represent the mixed signal according to a simple or double temperature event, characterized by deviations from the reference curve ( 41 ), starting at ( 42b ), respectively ( 43b ), and ending at ( 42c ), respectively ( 43c ). The latter mixed signals, ( 42 ), respectively. ( 43 ), end at ( 46 ), respectively ( 47 ).

The deflection at mixed signal ( 42 ) between times ( 42b ) and ( 42c ) now results from a local hotplate ( 13 ), which are connected to a signal line from 12 ) acts.

From a local rash of a mixed signal above a reference curve, the expert concludes that locally a cold spot must prevail, as cold spots act exactly opposite to heat waves on the reflection factors in the cable - continue the statements made to determine the temperature and the location of an impurity also for Local cold spots valid mutatis mutandis. Due to the characteristic of the local dielectric constant change to be used according to the invention, for the example of the single-temperature event (curve (FIG. 43 )), two local reflection factors which are indirectly reflected by the returning part ( R ) of the mixed signal ( S ) at the points ( 42b ) and ( 42c ) can be localized. The inventively mathematically to be integrated differential area ( 42a ) gives a capacitance value that correlates directly with the temperature (cf. 7 ).

Next is in 4 to realize that in mixed signal ( 43 ) next to a first local hot spot, now additionally a second local hot spot is present: Between the times ( 43b ) and ( 43c ) have resulted in further local reflection factors due to a local change in temperature, which is now also derived from the area integral ( 43a ) is convertible to a temperature. The skilled person recognizes from the larger difference surface that the hot spot resulting from ( 42a ) is warmer than that of ( 43a ).

The person skilled in the art will understand that the dates ( 42b ) 42c ), such as ( 43b ) 43c ) with a known signal speed information about the location of the temperature events ( 13 ) can be trivially calculated.

The mixed signal endpoints ( 46 ) 47 ) of the mixed signals ( 42 ), respectively ( 43 ) arise through the in DE10 2013 227 051 A1 already mentioned time delays due to the line impedance change in the hot spot and can optionally be used in addition to a further characterization of local temperature events.

1. a) unterhalb (für homogene Temperaturen über der Referenz), sowie
2. b) oberhalb (für homogene Temperaturen unter der Referenz) aus.

In the in 5 It can be seen that the mixed signal ( 51 ) does not draw any conclusions about local temperature events. It can be seen that the maximum amplitude ( 53 ) of the mixed signal ( 51 ) constant and below that of the reference signal ( 41 ) remains. At the same time, a propagation delay is again formed - to be recognized by the delay ( 52 ) across from ( 45 ). Phenomenologically, this type of mixed signal is due to a constant over the entire signal line length displacement of the line impedance from that at to explain homogeneous reference temperature. As a result, a constant plateau of the mixed signal now forms

1. a) below (for homogeneous temperatures above the reference), as well
2. b) above (for homogeneous temperatures below the reference).

1. a) sich nach hinten, für homogene Temperaturen über der Referenz, sowie
2. b) nach vorne, für homogene Temperaturen unter der Referenz, verschiebt.

At the same time it can be seen that the duration of the mixed signal end ( 52 )

1. a) to the rear, for homogeneous temperatures above the reference, as well
2. b) moves forward, for homogeneous temperatures below the reference.

An in 6 shown graph ( 60 ) shows an example of a typical output curve ( 61 ), which exemplifies a first temperature event of the temperature ( 64 ) formed between the coordinates ( 64a ) and ( 64b ), as well as a second temperature temperature ( 65 ) formed between the coordinates ( 65a ) and ( 65b ), in each case along the signal cable tree ( 12 ), Show. The temperature along the signal wiring harness that prevails outside the temperature events is set between the coordinates ( 62 ) and ( 63 ) with the temperature ( 66 ) and corresponds to the reference temperature (see. 4 , Signal ( 41 )).

The skilled artisan recognizes that the arrangement 1 not on the number four of the signal lines ( 14a-d ) is limited and can be extended accordingly application oriented.

An in 7 graph ( 70 ) shows the experimentally measured relationship between the determined capacity of a thermally induced defect and the corresponding temperature along a measuring arrangement (cf. 1 and 2 ).

The particular combination of elements and features in the foregoing description of embodiments is merely exemplary. Furthermore, of course, combinations, and replacement and replacement of the respective elements and embodiments are possible. Clearly, other variations, modifications, and implementations by a person skilled in the art are not excluded, but are expressly assigned to the spirit and the ambition of the invention.

LIST OF REFERENCE NUMBERS

10

First measuring arrangement.

11

Signal transceiver.

12

Sensor wiring harness.

13

Local hot spot.

14a-d

Signal lines.

15

Components facial expressions.

20

Extended measuring arrangement.

30

Cross-sectional view.

31

Insulation material.

40

Mixed signal representation.

41

Reference mixed signal.

42

Mixed signal at single temperature event,

42a

Signal surface first temperature event.

42b

Eventstart first temperature event.

42c

Eventende first temperature event.

43

Mixed signal at double-temperature event,

43a

Signal surface second temperature event.

43b

Event start second temperature event.

43c

Eventende second temperature event.

44

Start reference mixing signal.

45

End reference mix signal.

46

End mixed signal at single temperature event.

47

End mixed signal at dual-temperature event.

48

Signal plateau reference mixing signal.

50

Extended mixed signal representation.

51

Mixed signal with homogeneous heating.

52

Signal end of the mixed signal with homogeneous heating.

53

Signal plateau of the mixed signal with homogeneous heating ..

60

Output graph temperatures with coordinates

61

Curve of the temperature at coordinate.

62

Start coordinate.

63

End coordinate.

64

Temperature of the first temperature event,

64a

Start of the first temperature event.

64b

End of the first temperature event.

65

Temperature of the second temperature event,

65a

Start of the second temperature event.

65b

End of the second temperature event.

66

reference temperature

70

Representation of measured capacity values over temperatures

T

Temperature.

O

Coordinate.

H

Hinlaufendes signal.

R

Returned signal.

S

Mixed signal.

t

Time.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2009/115127 A1 [0002, 0003]
• US 5,185,594 A [0002, 0003]
• DE 102013227051 A1 [0002, 0004, 0005, 0029]
• WO 2009/046751 A1 [0002, 0005]

Claims (8)

Measuring arrangement (10) for temperature determination by means of a transceiver unit (11) for simultaneous feeding, data acquisition and analysis of an overall signal (S) consisting of the sum of a signal (H) and signal (R), characterized in that the transceiver unit (11) generates a signal (11). H) is driven into a first sensor line, for example (14a), as a subset of a sensor wiring harness (12), the transceiver unit for determining and evaluating a change of a surface integral (42) due to the thermal deviation of the local line impedance for deriving the temperature (T), and their respective location (O) is formed. a. Measuring arrangement (10) according to Claim 1 , characterized in that additionally as a further embodiment, a mimic (15) connected to a cable harness (12) represents a plurality of electrically interconnected elements of a secondary, arbitrary application with any desired impedance. b. Measuring arrangement (10) according to Claim 1 , characterized in that in addition as a further embodiment, the mimic (15) connected to the sensor wiring harness (12) additionally contains energy stores of variable electrical voltage, which are determined by the transceiver unit (11) in its energy position. c. Measuring arrangement (10) according to Claim 1 , characterized in that in addition as a further embodiment, the routing of the plurality of signal lines (14a-d) is formed suitably due to the application (20), for the best possible thermal coupling to be monitored, thermally sensitive components. Measuring arrangement (10) according to Claim 1 , characterized in that the plurality of sensor lines (14a-d) each with a material having a thermally dependent dielectric constant is wrapped (31). a. Measuring arrangement (10) according to Claim 2 , characterized in that additionally as a further embodiment, the sensor lines each enveloping material (31) preferably each has identical thermal properties. b. Measuring arrangement (10) according to Claim 2 , characterized in that additionally as a further embodiment, the sensor lines each enveloping material (31) preferably acts electrically insulating. c. Measuring arrangement (10) according to Claim 2 , characterized in that additionally as a further embodiment, a material of the signal conductor (14a-d) has a preferably small cross section. d. Measuring arrangement (10) according to Claim 2 , characterized in that additionally as a further embodiment, a composite of signal conductors (14a-d) has a further enveloping outer jacket of any material. Measuring arrangement (10) according to Claim 1 , characterized in that the plurality of sensor lines (14a-d) of the sensor wiring harness (12) is formed from a preferably stranded composite of sensor lines with each enclosing insulation material (31). Transceiver unit (11) from a measuring arrangement according to one of the preceding claims, characterized in that it is capable of forming the differential area of a voltage normalized reference signal (51) from a signal (52). Method for determining the temperature and the corresponding location of a plurality of temperature events (13) along a signal cable tree (12), comprising the steps: (1) driving a signal (H) into a signal line (14a) or (14b) or (14c) or (14d) associated with a signal cable tree, (2) Time-referenced recording voltage values of the mixed signal (41), or (42), or (43) consisting of the signal (H) and the returning signal (R), (3) normalization of the mixing signal to a suitable voltage value, (4) periodically performing steps 1 to 3 to form and store a reference signal (41), (5) repetition of steps 1 to 3 to form the mixing signal at unknown temperature, (6) mathematical integration of the area between a previously measured reference signal (41) and a mixed signal (42), or (43), (7) calculating a difference capacity value from the previous step, (8) determination of the temperature (T) by means of differential capacitance value from a calibration curve (70), (9) determination of the location (O) from the transit time since the start of the signal (44) to the occurrence of the temperature event (42b) taking into account a known signal propagation speed, (10) repetition of steps 1 to 7 to determine further temperature values and locations, if further difference surfaces (42b) exist, (11) Output of an information matrix with the temperature values, together with associated local values. Method for determining a locally homogeneously distributed temperature along a signal cable tree (12), characterized in that it is determined by means of a transceiver unit (11) by comparing the signal height at unknown temperature (53) with the signal height at reference temperature (48). Method according to Claims 4, 5, 6, characterized in that a transit time difference between the reference signal (41) and the mixed signal (42), or (43), or (51) is preferably complementary to the maximization the accuracy in the temperature determination are to be used. Measuring arrangement (10) according to one of the preceding claims, characterized in that a transceiver unit (11) is able to convert simple and multiple temperature events according to the statements in claims 4, 5, 6 and 7 into temperature and corresponding local values.

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