THERMALLY CONTROLLED ELECTRONIC DEVICE

Abstract

An electronic device includes at least one electronic component, a gradient heat-flux sensor GHFS based on thermoelectric anisotropy and conducting heat generated by the electronic component, and a controller adapted to manage electrical current of the electronic component at least partly on the basis of an electrical control signal generated by the gradient heat-flux sensor and proportional to a heat-flux through the gradient heat-flux sensor. Therefore, the electrical current and thereby also the heat generation of the electronic component are managed directly on the basis of the heat-flux generated by the electronic component. Thus, the electrical current can be managed without a need for voltage and current measurements which may be challenging to be carried out with a sufficient bandwidth especially when the switching frequency of the electronic component is on a range from hundreds of kHz to few MHz.

Claims

1-16. (canceled)

17. An electronic device comprising: at least one electronic component, a heat-sink element, a gradient heat-flux sensor based on thermoelectric anisotropy and adapted to conduct heat generated by the electronic component and to generate an electrical control signal proportional to a heat-flux through the gradient heat-flux sensor, and a controller responsive to the electrical control signal and adapted to manage electrical current of the electronic component at least partly on the basis of the electrical control signal, wherein the gradient heat-flux sensor (102) constitutes at least a part of a heat conduction path from a heat generating portion of the electronic component to the heat-sink element.

18. An electronic device according to claim 17, wherein the gradient heat-flux sensor comprises at least two sensor elements placed side by side so as to achieve a situation in which disturbance voltages induced by a changing magnetic flux to the sensor elements are substantially same and electrically connected in series so that the disturbance voltages induced by the changing magnetic flux to the sensor elements are adapted to cancel each other at least partly.

19. An electronic device according to claim 17, wherein the controller is adapted to reduce switching frequency of the electronic component in response to a situation in which the electrical control signal is indicative of a heat-flux exceeding a first safety limit.

20. An electronic device according to claim 17, wherein the controller is adapted to activate short-circuit protection of the electronic component in response to a situation in which the electrical control signal is indicative of a heat-flux exceeding a second safety limit.

21. An electronic device according to claim 17, wherein the electronic device comprises another electronic component and another gradient heat-flux sensor adapted to conduct heat generated by the other electronic component and to produce another electrical control signal proportional to a heat-flux through the other gradient heat-flux sensor, and wherein the electronic components are parallel connected and the controller is adapted to control operation of the parallel connected electronic components at least partly on the basis of the electrical control signals so as to balance electrical currents of the parallel connected electronic components.

22. An electronic device according to claim 17, wherein the gradient heat-flux sensor comprises anisotropic material for generating the electrical control signal proportional to a first temperature gradient component transverse to a second temperature gradient component parallel with the heat-flux through the gradient heat-flux sensor.

23. An electronic device according to claim 22, wherein the anisotropic material is bismuth.

24. An electronic device according to claim 17, wherein the gradient heat-flux sensor comprises a multilayer structure for generating the electrical control signal proportional to a first temperature gradient component transverse to a second temperature gradient component parallel with the heat-flux through the gradient heat-flux sensor, layers of the multilayer structure being oblique with respect to a surface of the gradient heat-flux sensor for receiving the heat-flux.

25. An electronic device according to claim 24, wherein the multilayer structure comprises first layers and second layers, the second layers being made of semiconductor material and being interleaved with the first layers and the first layers being made of metal, metal alloy, or semiconductor material.

26. An electronic device according to claim 17, wherein the electronic component comprises at least one of the following: a bipolar junction transistor “BJT”, a diode, an insulated gate bipolar transistor “IGBT”, a thyristor, a gate-turn-off thyristor “GTO”, a metal-oxide-semiconductor field-effect transistor “MOSFET”, Integrated Gate-Commutated Thyristor “IGCT”, Injection-Enhanced Gate Transistor “IEGT”.

27. A method comprising: receiving (301) an electrical control signal from a gradient heat-flux sensor based on thermoelectric anisotropy and conducting heat generated by an electronic component, the gradient heat-flux sensor generating the electrical control signal proportional to a heat-flux through the gradient heat-flux sensor and the gradient heat-flux sensor constituting at least a part of a heat conduction path from a heat generating portion of the electronic component to a heat-sink element, and managing (302) electrical current of the electronic component at least partly on the basis of the electrical control signal.

28. A method according to claim 27, wherein the electrical control signal is received from at least two side-by-side placed and series connected sensor elements of the gradient heat-flux sensor, disturbance voltages induced by a changing magnetic flux to the sensor elements being substantially same due to the side-by-side placing of the at least two sensor elements and the disturbance voltages cancelling each other at least partly due to the series connection of the at least two sensor elements.

29. A method according to claim 27, wherein the method comprises reducing switching frequency of the electronic component in response to a situation in which the electrical control signal is indicative of a heat-flux exceeding a first safety limit.

30. A method according to claim 27, wherein the method comprises activating short-circuit protection of the electronic component in response to a situation in which the electrical control signal is indicative of a heat-flux exceeding a second safety limit.

31. A method according to claim 27, wherein the method comprises balancing the electrical current of the electronic component with electrical current of another electronic component on the basis of the electrical control signal and another electrical control signal received from another gradient heat-flux sensor conducting heat generated by the other electronic component and generating the other electrical control signal proportional to a heat-flux through the other gradient heat-flux sensor.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0017] Exemplifying and non-limiting embodiments of the invention and their advantages are explained in greater detail below in the sense of examples and with reference to the accompanying drawings, in which:

[0018] FIGS. 1a, 1b and 1c illustrate an electronic device according to an exemplifying and non-limiting embodiment of the invention,

[0019] FIGS. 2a, 2b and 2c illustrate a part of an electronic device according to an exemplifying and non-limiting embodiment of the invention, and

[0020] FIG. 3 shows a flowchart of a method according to an exemplifying and non-limiting embodiment of the invention for managing electrical current of an electronic component.

DESCRIPTION OF THE EXEMPLIFYING EMBODIMENTS

[0021] FIGS. 1a illustrates an electronic device according to an exemplifying and non-limiting embodiment of the invention. In this exemplifying case, the electronic device is a frequency converter adapted to receive electrical energy from a three-phase network via terminals 132 and to supply three-phase alternating voltage via terminals 133. The electronic device comprises six electronic components each comprising a controllable power electronic switch and an antiparallel connected diode. In FIG. 1a, one of the electronic components is denoted with a reference number 101. In this exemplifying case, the controllable power electronic switches of the electronic components are insulated gate bipolar transistors “IGBT”. In electronic devices according to such exemplifying and non-limiting embodiments of the invention that the electronic devices comprise one or more power electronic switches, each power electronic switch can be for example an IGBT, a bipolar junction transistor “BJT”, a diode, a thyristor, a gate-turn-off thyristor “GTO”, a metal-oxide-semiconductor field-effect transistor “MOSFET”, an Integrated Gate-Commutated Thyristor “IGCT”, or an Injection-Enhanced Gate Transistor “IEGT”.

[0022] The electronic device comprises gradient heat-flux sensors “GHFS” which are adapted to conduct heat generated by the electronic components and to generate electrical control signals 130 which are linearly or non-linearly proportional to heat-fluxes through the gradient heat-flux sensors. In FIG. 1a, the electrical control signal generated by the gradient heat-flux sensor adapted to conduct the heat generated by the electronic component 101 is denoted with a reference number 131. The electronic device comprises a controller 103 responsive to the electrical control signals 130 and adapted to manage electrical currents of the electronic components at least partly on the basis of the electrical control signals. In addition to the electrical control signals 130, the controller 103 can be adapted to manage the electrical currents on the basis of one or more measured temperatures, measured values of the electrical currents, and/or other appropriate information.

[0023] FIG. 1b shows a side view of the electronic component 101. The gradient heat-flux sensor is shown with the aid of a partial section view shown in FIG. 1b. The gradient heat-flux sensor is denoted in FIG. 1b with a reference number 102. In this exemplifying case, the gradient heat-flux sensor 102 constitutes a part of a heat conduction path from a heat generating portion of the electronic component 101 to a heat-sink element 104. The heat-sink element 104 may comprise cooling fins for conducting heat to the ambient air and/or cooling ducts for conducting cooling fluid, e.g. water. In this exemplifying case, the electronic component 101 comprises a baseplate 134 which is against the heat-sink element. The heat-sink element 104 comprises a cavity for the gradient heat-flux sensor 102 so that the gradient heat-flux sensor is against the baseplate 134 of the electronic component 101. In FIG. 1b, the heat flow from the electronic component 101 to a heat-sink element 104 is depicted with wavy arrows one of which is denoted with a reference number 135. In FIG. 1b, one of the main current terminals of the electronic component 101 is denoted with a reference number 136 and a control terminal, i.e. a gate connection of the IGBT, is denoted with a reference number 137.

[0024] In the exemplifying electronic device illustrated in FIGS. 1a and 1b, the gradient heat-flux sensors are located on surfaces of the electronic components, i.e. against the baseplates of the electronic components. This is however not the only possible choice. It is also possible that a gradient heat-flux sensor is embedded to e.g. the base plate of an electrical component or to another place of the casing of the electrical component. It is also possible that a gradient heat-flux sensor is an integrated element of an electrical component for example so that the gradient heat-flux sensor is inside the casing of the electrical component. In cases where an electrical component is a module type component which comprises e.g. many semiconductor units such as e.g. IGBTs, the module type component may comprise many gradient heat-flux sensors so that each semiconductor unit is provided with one of the gradient heat-flux sensors. Thus, it is possible to monitor the thermal behavior of the module type component in a semiconductor unit specific manner.

[0025] It is to be noted that the invention is not limited to any particular ways to arrange a gradient heat-flux sensor to conduct heat generated by an electronic component.

[0026] In an electronic device according to an exemplifying and non-limiting embodiment of the invention, the controller 103 is adapted to reduce the switching frequency of the electronic components in response to a situation in which the electrical control signals 130 are indicative of heat-fluxes exceeding a first safety limit. Reducing the switching frequency is actually managing high frequency components of the electrical currents. Thus, the reducing the switching frequency can be deemed to represent a way to manage the electrical currents of the electronic components.

[0027] In an electronic device according to an exemplifying and non-limiting embodiment of the invention, the controller 103 is adapted to activate short-circuit protection of the electronic components in response to a situation in which the electrical control signals 130 are indicative of heat-fluxes exceeding a second safety limit. The second safety limit is advantageously higher than the above-mentioned first safety limit used for controlling the switching frequency. The short-circuit protection may comprise for example controlling one or more of the electronic components to a non-conducting state and/or otherwise switching off one or more of the currents of the electronic components.

[0028] FIG. 1c shows a perspective view of the gradient heat-flux sensor 102. The viewing directions related to FIGS. 1b and 1c are illustrated with the aid of a coordinate system 190 shown in FIGS. 1b and 1c. The gradient heat-flux sensor 102 comprises sensor elements 111, 112, 113, 114, 115, 116, 117, and 118 electrically connected in series so that disturbance voltages induced by a changing magnetic flux to the sensor elements 111-118 are adapted to cancel each other at least partly. The voltage U shown in FIG. 1c represents the electrical control signal generated by the gradient heat-flux sensor 102. Advantageously, the gradient heat-flux sensor comprises strips of electrically insulating material between adjacent ones of the sensor elements 111-118. Furthermore, the gradient heat-flux sensor 102 may comprise an insulator plate 119 that can be made of material which is electrically insulating but which has sufficient heat conductivity. The insulator plate 119 can be made of for example mica. Depending on the operating environment of the gradient heat-flux sensor 102, there can be a similar other insulator plate on the other sides of the sensor elements 111-118. The other insulator plate is not shown in FIG. 1c.

[0029] In an electronic device according to an exemplifying and non-limiting embodiment of the invention, each of the sensor elements 111-118 comprises anisotropic material for generating a part of the voltage U which is proportional to a first temperature gradient component transverse to a second temperature gradient component parallel with the heat-flux through the gradient heat-flux sensor. In this case, the first temperature gradient component is parallel with the x-axis of the coordinate system 190 and the second temperature gradient component is parallel with the z-axis of the coordinate system 190. The anisotropic material can be for example bismuth, and each of the sensor elements 111-118 can be a single crystal of bismuth.

[0030] In an electronic device according to an exemplifying and non-limiting embodiment of the invention, each of the sensor elements 111-118 comprises a multilayer structure for generating a part of the voltage U. The layers of the multilayer structure are oblique with respect to the surface of the gradient heat-flux sensor for receiving the heat-flux from the electronic component. The multilayer structure may comprise first layers and second layers so that the second layers are interleaved with the first layers. The second layers can be made of for example semiconductor material, and the first layers can be made of for example metal or metal alloy or of semiconductor material different from the semiconductor material of the first layers.

[0031] It is to be noted that the above-described gradient heat-flux sensors are merely examples and that the invention in not limited to any particular materials and/or structures and/or manufacturing methods of gradient heat-flux sensors.

[0032] FIG. 2a illustrates a part of an electronic device according to an exemplifying and non-limiting embodiment of the invention. In this exemplifying case, the electronic device comprises two parallel connected electronic components 201 and 221. Each of the electronic components comprises a controllable power electronic switch and an antiparallel connected diode. In this exemplifying case, the controllable power electronic switch is an insulated gate bipolar transistor “IGBT”. The electronic device comprises gradient heat-flux sensors “GHFS” adapted to conduct heat generated by the electronic components and to generate electrical control signals proportional to heat-fluxes through the gradient heat-flux sensors. The electronic device comprises a controller 203 responsive to the electrical control signals and adapted to manage electrical currents of the electronic components at least partly on the basis of the electrical control signals. The controller 203 is adapted to control the operation of the parallel connected electronic components 201 and 221 at least partly on the basis of the electrical control signals so as to balance electrical currents of the parallel connected electronic components. Furthermore, the controller can be adapted to control the switching frequency of the electronic components 201 and 221 and/or to control the short circuit “SC” protection on the basis of the electrical control signals generated by the gradient heat-flux sensors. In addition to the above-mentioned electrical control signals, the controller 203 can be adapted to manage the electrical currents of the electronic components 201 and 221 on the basis of one or more measured temperatures, measured values of the electrical currents, and/or other appropriate information.

[0033] FIGS. 2b and 2c show side views of the electronic components 201 and 221. The gradient heat-flux sensors are shown with the aid of partial section views shown in FIGS. 2b and 2c. The gradient heat-flux sensors are denoted in FIGS. 2b and 2c with reference numbers 202 and 222.

[0034] FIG. 3 shows a flowchart of a method according to an exemplifying and non-limiting embodiment of the invention for managing electrical current of an electronic component. The method comprises the following actions: [0035] action 301: receiving an electrical control signal from a gradient heat-flux sensor “GHFS” based on thermoelectric anisotropy and conducting heat generated by the electronic component, the gradient heat-flux sensor generating the electrical control signal proportional to a heat-flux through the gradient heat-flux sensor, and [0036] action 302: managing the electrical current of the electronic component at least partly on the basis of the electrical control signal.

[0037] In a method according to an exemplifying and non-limiting embodiment of the invention, the electrical control signal is received from at least two series connected sensor elements of the gradient heat-flux sensor, where disturbance voltages induced by a changing magnetic flux to the sensor elements cancel each other at least partly in the series connection of the at least two sensor elements.

[0038] A method according to an exemplifying and non-limiting embodiment of the invention comprises reducing switching frequency of the electronic component in response to a situation in which the electrical control signal is indicative of a heat-flux exceeding a first safety limit.

[0039] A method according to an exemplifying and non-limiting embodiment of the invention comprises activating short-circuit protection of the electronic component in response to a situation in which the electrical control signal is indicative of a heat-flux exceeding a second safety limit.

[0040] A method according to an exemplifying and non-limiting embodiment of the invention comprises balancing the electrical current of the electronic component with electrical current of another electronic component on the basis of the electrical control signal and another electrical control signal received from another gradient heat-flux sensor conducting heat generated by the other electronic component and generating the other electrical control signal proportional to a heat-flux through the other gradient heat-flux sensor.

[0041] The specific examples provided in the description given above should not be construed as limiting the applicability and/or interpretation of the appended claims. It is to be noted that lists and groups of examples given in this document are non-exhaustive lists and groups unless otherwise explicitly stated.