MEASURING THE TEMPERATURE OF AN EXOTHERMIC ELECTRICAL COMPONENT COOLED BY MEANS OF A COOLING LIQUID

Abstract

The invention relates to a measurement system (114) of a temperature (T) of an exothermic electrical element (106WHS) cooled by means of a coolant, comprising: - a temperature sensor (116) designed to measure a temperature (TEAU) of the coolant; and - a dynamic model (MDIS) of a thermal dissipation link (LDIS) between the exothermic electrical element (106WHS) and the coolant, designed to estimate the temperature (T) of the exothermic electrical element (106WHS) from an estimated temperature (T'EAU) of the coolant.The measurement system (114) further comprises: - a dynamic model (MPARA) of a parasitic thermal link (LPARA) between a parasitic heat source (104) and the temperature sensor (116), designed to estimate, from an estimate of a thermal power emitted (P) by the parasitic heat source (104), a parasitic heating (TPARA) of the temperature sensor (116) caused by the parasitic heat source (104) through the parasitic thermal link (LPARA); and - a compensation module (118) designed to provide the estimated temperature (T'EAU) of the coolant by compensating, in the measured temperature (TEAU) of the coolant, the parasitic heating (TPARA).

Description

Title of the invention: MEASUREMENT OF THE TEMPERATURE OF AN EXOTHERMIC ELECTRICAL COMPONENT COOLED BY MEANS OF A COOLING LIQUID Technical field of the invention

[0001] The present invention relates to a system for measuring the temperature of an exothermic electrical element cooled by means of a coolant, an electrical installation comprising such a measuring system and a mobility device comprising such an electrical installation.

[0002] A mobility device is, for example, a motorized land vehicle, a train, an aircraft, or a drone. A motorized land vehicle is, for example, a car, a motorcycle, a motorized bicycle, or a motorized wheelchair. Technological background

[0003] Prior art is known a system for measuring the temperature of an exothermic electrical element cooled by means of a coolant, of the type comprising: - a temperature sensor designed to measure the temperature of the coolant; and - a dynamic model of a thermal dissipation link between the exothermic electrical element and the coolant, designed to estimate the temperature of the exothermic electrical element from an estimated temperature of the coolant.

[0004] A dynamic model is a set of mathematical equations evolving over time, that is, in which time is a variable. For example, these mathematical equations are differential equations of time.

[0005] The dynamic model therefore makes it possible to simulate heat dissipation through the thermal dissipation link. Thus, by knowing the temperature of the coolant, it is possible to determine the temperature of the monitored exothermic electrical element.

[0006] For example, the monitored exothermic electrical element may be a transistor, for example in a switching inverter, which has a junction temperature that must not be exceeded, otherwise the transistor will be damaged. Thus, the transistor temperature is important to know.

[0007] In the prior art measurement system, the measured temperature is directly used as the estimated temperature in the dynamic model, which leads to a non-negligible margin of error in estimating the temperature of the exothermic electrical element.

[0008] It may therefore be desirable to provide a measurement system which makes it possible to overcome at least some of the aforementioned problems and constraints. Summary of the invention

[0009] A measurement system of the aforementioned type is therefore proposed, characterized in that it further comprises: - a dynamic model of a parasitic thermal link between a parasitic heat source and the temperature sensor, designed to estimate, from an estimate of the thermal power emitted by the parasitic heat source, a parasitic heating of the temperature sensor caused by the parasitic heat source through the parasitic thermal link; and - a compensation module designed to provide the estimated temperature of the coolant by compensating for parasitic heating in the measured temperature of the coolant.

[0010] Thus, thanks to the invention, the estimation of the temperature of the coolant used in the dynamic model of the dissipation link is more accurate, and therefore also the estimation of the temperature of the exothermic electrical element.

[0011] The invention may further include one or more of the following optional features, according to any technically possible combination.

[0012] Optionally, the parasitic heat source is an electrical circuit.

[0013] Optionally also, the electrical circuit is a switching converter designed to perform a conversion between a direct voltage and phase voltages, in order to provide phase currents.

[0014] Optionally also, the measurement system further includes a voltage sensor designed to measure the DC voltage and a current sensor designed to measure one of the phase currents, and the thermal power emitted by the parasitic heat source is estimated from the measured DC voltage and the measured phase current.

[0015] Optionally also, the exothermic electrical element belongs to the electrical circuit.

[0016] Optionally, the exothermic electrical element is a transistor, a capacitor, or a busbar of the converter.

[0017] Optionally, the temperature of the exothermic electrical element is further estimated from the thermal power emitted.

[0018] Optionally, the measurement system also includes a dynamic model of the heat source, designed to estimate the thermal power emitted by the heat source.

[0019] Optionally also, the dynamic thermal model of a parasitic thermal link implements a Cauer thermal model.

[0020] Optionally also, the dynamic thermal model of a parasitic thermal link implementing a Cauer thermal model includes a succession of at least two blocks comprising an input node and an output node, as well as a capacitance between the input node and an electrical ground and a resistance connected between the input node and the output node of the block.

[0021] Alternatively, the dynamic thermal model of a parasitic thermal bond implements a Foster thermal model.

[0022] An electrical installation comprising: is also proposed - a channel for circulating a coolant; - an exothermic electrical element cooled by means of the liquid cooling; - a thermal dissipation bond between the exothermic electrical element and the coolant; and - a measurement system according to the invention.

[0023] A mobility device comprising an electrical installation according to the invention is also proposed. Brief description of the figures

[0024] The invention will be better understood with the aid of the following description, given solely by way of example and made with reference to the accompanying drawings in which: - Figure 1 is a functional diagram of an electrical installation in which the invention is implemented, and - [Fig.2] is a functional diagram of a computer system for the implementation of dynamic thermal models used in the electrical installation of [Fig.1]. Detailed description of the invention

[0025] With reference to [Fig.1], an electrical installation 100 in which the invention is implemented will now be described.

[0026] The electrical installation 100 first includes a DC voltage source 102, such as a battery, having two terminals "+" and "-" and designed to provide a DC voltage VBat between these two terminals "+" and "-".

[0027] The electrical installation 100 further comprises a switching inverter 104. As is known in itself, the switching inverter 104 is an electrical circuit designed to convert the DC voltage VBat into phase voltages UG, Uv, Uw, in order to provide as many phase currents lu, Iv, Iw as there are phase voltages Uu, Uv, Uw. For example, the phase voltages Uu, Uv, Uw and the phase currents IG, Iv, Iw are three in number, so as to form a three-phase power supply.

[0028] The switching inverter 104 further comprises several switches 106UHs, 106Uls, 106VHs, 106Vls, 106WHs, 106Wls.Each of them is preferably a controllable semiconductor switch, such as a transistor, for example a metal-oxide-semiconductor field-effect transistor (MOSFET), a silicon metal-oxide-semiconductor field-effect transistor (SiMOSFET), a silicon carbide metal-oxide-semiconductor field-effect transistor (SiCMOSFET), an insulated-gate bipolar transistor (IGBT), or a gallium nitride field-effect transistor (GaN). FET).

[0029] For example, the switching inverter 104 has several switching arms 106U, 106V, 106W. Each switching arm 106U, 106V, 106W is connected between the two terminals "+" and "-" of the DC voltage source 102 and has two switches 106UHs and 106ULS, 106VHs and 106VLS, 106WHs and 106WLS connected to each other at a midpoint having the associated phase voltage Uu, Uv, Uw and from which the associated phase current IG, Iv, Iw is supplied.

[0030] The switching inverter 104 includes, for example, a base plate 108 on which the switches 106UHs and 106ULs, 106VHs and 106Vls, 106WHs and 106WLS are mounted. This base plate 108 includes, for example, a stack of several layers, for example, a copper layer and a ceramic layer.

[0031] The electrical installation 100 further includes a control device 110 for the switches 106UHs, 106ULS, 106VHs, 106VLS, 106WHs, 106WLS of the switching inverter 104, in order to provide, for example, substantially sinusoidal phase currents Iu, Iv, Iw that are out of phase with each other. For example, the control device 110 is designed to control the switching inverter 104 according to certain parameters, which may be fixed or variable over time, such as one or more of the following: - a modulation index m (ratio between the DC voltage Vbat and an amplitude of the phase currents); - a power factor cos <p (déphasage entre les tensions de phase moyennes et courants phase) ; -      une fréquence commutation fsw des commutateurs       une fe une stratégie commande l (par exemple, pleine onde, svpwm, etc.).

[0032] l’installation électrique 100 comporte en outre machine 112 conçue pour recevoir uu, uv, uw lu, iv, iw.

[0033] un canal circulation 113 d’un liquide refroidissement l’onduleur à 104, particulier 106uhs, 106uls, 106vhs, 106vls, 106whs, 106wls-

[0034] en particulier, la plaque base 108 est plaquée contre face externe du 113.

[0035] ainsi, il existe liaison thermique dissipation ld1s le commutateur 106whs refroidissement. par comme illustré, traverse

[0036] système mesure 114 d’une température t 106uls, 106vls, 106wls, dans l’exemple illustré.

[0037] le tout d’abord capteur 116 conçu mesurer teau placé l’extérieur 113, mais ce dernier. outre, plus proche possible dont recherchée. se trouve très 104.

[0038] peut être perturbé par source chaleur parasite proche. 104 lui-même constituer telle parasite. effet, fait proximité avec lpara non négligeable 116.

[0039] convient compenser, 116, l’effet

[0040] modèle dynamique mpara (l’onduleur illustré) ce estimer, partir estimation puissance p dégagée illustré), échauffement tpara causé au travers lpara.

[0041] sous forme simulation circuit électrique, où grandeurs électriques représentent illustrée, modélisée succession blocs bparai, bpara2 présentant chacun nœud d’entrée neparai , nepara2 sortie nsparai, nspara2, connecté bloc suivant. théorie, chaque modélise couche matériau laquelle passe cependant, pratique, l’identification ces couches définition correspondants difficile réaliser. nombre sera plutôt choisi compromis calcul nécessaire faire tourner l’adéquation données expérimentales sur dans ainsi deux bpara2, car a été déterminé qu’un seul n’était pas suffisant d’autres cas, trois ou pourraient utilisés. les sont chaînés uns autres (le suivant). nspara2 dernier connectée masse calculer (c’est-à-dire écart température) température, représentée courant i(p) prélevé premier

[0042] cas cauer, comprend capacité résistance bloc. alternativement, foster

[0043] module compensation 118 fournir estimée t’eau cette obtenue compensant, mesurée refroidissement, réchauffement tpara. formule suivante : t’eau="TEAu"

[0044] pour déterminer md1s estimer t’ha e précise quela

[0045] ld1s. utilisant décrit précédemment, succédant point chaud vers froid. bd1si, bd1s2. la fournie tant que tension v(t’eau) nsdis2 bd1s2, fourni ned1s i bd1s b comme bd1sb bd1s2 peuvent ceux cauer (comme bien foster.

[0046] p, exemple ms c illustré). msc utilise entrée mesures iw continue vbat. obtenir mesures, 120 vbat 122

[0047] msc ailleurs utiliser plusieurs paramètres m, cosq>, fsw, fe and L.

[0048] In some embodiments, as in the illustrated example, the temperature T determined by the measuring system 114 can be supplied to the control device 110. The latter is then, for example, designed to compare the temperature T to the junction temperature Tj and, if the temperature T exceeds the junction temperature Tj, to control the switching inverter 104 in order to reduce the electrical power passing through the switches 106UHs, 106ULs, 106VHs, 106VLs, 106WHs, 106WLs, and thus limit their heating.

[0049] Alternatively, the temperature T could be supplied to a device (not shown) for circulating the coolant (such as a pump) to control a flow rate of the coolant circulation as a function of the temperature T.

[0050] With reference to [Fig.2], the measurement system 214 may include a computer system 200 to implement one or more of the models Msc, MD1S, MPARA.

[0051] The computer system 200 includes a data processing unit 202 (such as a microprocessor) and a main memory 204 (such as RAM, from the English "Random Access Memory") accessible by the processing unit 202. The computer system 200 further includes, for example, a network interface and / or a computer-readable medium, such as, for example, a local medium 206 (such as a local hard disk drive) or a remote medium (such as a remote hard disk drive accessible via the network interface through a communication network) or a removable medium (such as a USB key, from the English "Universal Serial Bus", or a CD, from the English "Compact Disc" or a DVD, from the English "Digital Versatile Disc") readable by means of an appropriate reader of the computer system 200 (such as a USB port or a CD and / or DVD disc drive).A computer program 208 containing instructions for the processing unit 202 is stored on local storage 206 and / or downloadable via the network interface. This computer program 208 is intended, for example, to be loaded into main memory 204, so that the processing unit 202 executes its instructions, in order to implement one or more of the MSc, MD1S, MPARA models.

[0052] In conclusion, it is clear that a measurement system such as the one described above allows for a better estimation of the temperature of the coolant, and therefore a better estimation of the temperature of the monitored exothermic electrical element.

[0053] It should also be noted that the invention is not limited to the embodiments described above. It will indeed be apparent to those skilled in the art that various modifications can be made to the embodiments described above, in light of the information just disclosed to them.

[0054] For example, the switching inverter could be reversible to operate as a rectifier.

[0055] In the detailed presentation of the invention given above, the terms used shall not be interpreted as limiting the invention to the embodiments set forth in this description, but shall be interpreted as including all equivalents which can be foreseen by a person skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims

Demands

1. A measurement system (114) for the temperature (T) of an exothermic electrical element (106WHs) cooled by means of a coolant, comprising: - a temperature sensor (116) designed to measure a temperature (TEAU) of the coolant; and - a dynamic model (MD1S) of a thermal dissipation link (LD1S) between the exothermic electrical element (106WHs) and the coolant, designed to estimate the temperature (T) of the exothermic electrical element (106WHs) from an estimated temperature (T'eau) of the coolant;characterized in that it further comprises: - a dynamic model (MPARA) of a parasitic thermal link (LPARA) between a parasitic heat source (104) and the temperature sensor (116), designed to estimate, from an estimate of a thermal power emitted (P) by the parasitic heat source (104), a parasitic heating (TPARA) of the temperature sensor (116) caused by the parasitic heat source (104) through the parasitic thermal link (LPARA); and - a compensation module (118) designed to provide the estimated temperature (T'EAU) of the coolant by compensating, in the measured temperature (TEAU) of the coolant, parasitic heating (TPARA).

2. Measurement system (114) according to claim 1, wherein the parasitic heat source (104) is an electrical circuit.

3. A measuring system (114) according to claim 2, wherein the electrical circuit is a switching converter designed to perform a conversion between a DC voltage (VBAt) and phase voltages (Uu, Uv, Uw), in order to provide phase currents (lu, Iv, Iw)-

4. A measuring system (114) according to claim 3, further comprising a voltage sensor (120) designed to measure DC voltage (VBAt) and a current sensor (122) designed to measure one of the phase currents (Iw), and in which the thermal power emitted (P) by the parasitic heat source (104) is estimated from the measured DC voltage (VBat) and the measured phase current (Iw).

5. Measurement system (114) according to any one of claims 2 to 4, wherein the exothermic electrical element (106WHs) belongs to the electrical circuit.

6. Measurement system (114) according to claim 3 or 4 and claim 5, wherein the exothermic electrical element (106WHs) is a transistor, a capacitor or a busbar of the converter.

7. Measurement system (114) according to claim 5 or 6, wherein the temperature (T) of the exothermic electrical element (106WHs) is further estimated from the thermal power emitted (P).

8. Measurement system (114) according to any one of claims 1 to 7, further comprising a dynamic model (Msc) of the heat source (104), designed to estimate the thermal power emitted (P) by the heat source (104).

9. Electrical installation (100) comprising: - a circulation channel (113) for a coolant; - an exothermic electrical element (106WHs) cooled by means of the coolant; - a thermal dissipation link (LD1S) between the exothermic electrical element (106WHs) and the coolant; and - a measuring system (114) according to any one of claims 1 to 8.

10. Mobility device comprising an electrical installation (100) according to claim 9.

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