A thermally controlled switch, composite power device and power electronic converter

Abstract

The application provides a heat-controlled switch, a composite power device and a power electronic converter. In the heat-controlled switch, one end of an elastic conductive structure is connected to the inner side of one current contact, and a clamping end is arranged on the elastic conductive structure and abuts against one end of a corresponding heat conductor. The other end of the heat conductor is fixed to the inner side of a corresponding thermal contact. When the heat conductor receives heat from the corresponding thermal contact greater than a preset amount, the heat conductor deforms, releases the clamping effect on the corresponding clamping end, and makes the other end of the elastic conductive structure contact or leave the inner side of the other current contact, thereby changing the on-off state between the two current contacts, generating a corresponding electrical signal in the external circuit connected to the heat-controlled switch, and achieving temperature protection. That is, the application does not need power supply, and can achieve corresponding temperature protection through only a single heat-controlled switch.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a thermally controlled switch, a composite power device, and a power electronic converter. Background Technology

[0002] Because the reliability of power semiconductors is crucial to the reliable operation of power electronic converters, practical power electronic products are usually equipped with corresponding protections for current, voltage, and temperature. However, in actual operation, power semiconductors can still experience abnormalities that lead to increased losses and even fires.

[0003] Currently, temperature protection for a single device often involves using temperature sensors such as thermistors to convert heat into electrical signals for protection. While this protection structure offers flexibility, it requires a corresponding power supply to function properly and is quite complex due to the large number of components involved. Summary of the Invention

[0004] In view of this, this application provides a thermally controlled switch, a composite power device, and a power electronic converter that do not require power supply and can achieve the corresponding temperature protection using only a single thermally controlled switch.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] The first aspect of this application provides a heat-controlled switch, comprising: an elastic conductive structure, at least two current contacts, and at least one heat conductor and its corresponding thermistor contact; wherein...

[0007] One end of the elastic conductive structure is connected to the inside of one of the current contacts.

[0008] The elastic conductive structure is provided with a locking end, which abuts against one end of the corresponding heat conductor;

[0009] The other end of the heat conductor is fixed to the inner side of the corresponding thermal contact.

[0010] The heat conductor is used to receive heat conduction from the corresponding thermal contact, and deforms when the heat received is greater than a preset amount, releasing the locking effect on the corresponding locking end, so that the other end of the elastic conductive structure contacts or leaves the inner side of another current contact.

[0011] Optionally, the elastic conductive structure includes: a conductive structural component and a spring;

[0012] The first end of the conductive structural component is used to connect to the inner side of the corresponding current contact.

[0013] The conductive structure is provided with the locking end. When the heat conductor abuts against the locking end, the spring is in a contracted state. When the heat conductor releases the locking end, the spring is in a relaxed state.

[0014] The second end of the conductive structure is used to contact or move away from the inner side of the corresponding current contact.

[0015] Optionally, the conductive structural component includes two movably connected cavities, allowing the length of the conductive structural component to be variable; the spring is disposed inside the conductive structural component along its length, with its two ends respectively abutting against the inner sides of both ends of the conductive structural component; or,

[0016] The first end of the conductive structure is connected to the inner side of the corresponding current contact via a conductive flexible material; the spring is wound around the outer side of the conductive structure, with one end fixed to a preset position inside the thermally controlled switch and the other end fixed to the conductive structure.

[0017] Optionally, the number of thermal contacts is two, and the elastic conductive structure further includes: a balancing component and internal contacts;

[0018] The second end of the conductive structure contacts or moves away from the inner side of the corresponding current contact through the internal contact; when the internal contact contacts the corresponding current contact, the elastic conductive structure enables current to flow between the two current contacts.

[0019] The second end of the conductive structural component also abuts against the inner side of the balancing component, and the outer two ends of the balancing component are respectively provided with a corresponding locking end.

[0020] Optionally, the balancing component includes: a balancing fulcrum and a balancing baffle;

[0021] The second end of the conductive structural component abuts against one side of the balance baffle through the balance fulcrum;

[0022] The other two ends of the balance baffle serve as the corresponding locking ends.

[0023] Optionally, the heat conductor is L-shaped, with one part used for deformation and connection to the corresponding thermal contact, and the other part used to abut against the corresponding locking end; or,

[0024] The heat conductor is Z-shaped, with its middle portion used for deformation, and its two ends used to connect to the corresponding thermal contacts and abut against the corresponding locking end, respectively.

[0025] Optionally, the heat conductor is a bimetallic sheet.

[0026] A second aspect of this application provides a composite power device, comprising: at least one power device and a thermally controlled switch as described in any of the first aspects above;

[0027] The power device is located within a preset range outside the corresponding thermal contact of the thermally controlled switch.

[0028] Optionally, the power device abuts against the corresponding thermal contact.

[0029] A third aspect of this application provides a power electronic converter, comprising: a main circuit and at least one thermally controlled switch as described in any of the first aspects above; the power devices in the main circuit are disposed within a preset range outside the corresponding thermal contact of the thermally controlled switch;

[0030] Alternatively, the power devices in its main circuit are composite power devices as described in the second aspect above.

[0031] Optionally, the thermally controlled switch is connected in series with the corresponding power device through its two current contacts, so as to cut off the corresponding fault current when the corresponding power device experiences thermal runaway; or,

[0032] The thermally controlled switch is connected in parallel with the corresponding power device or its power supply through its two current contacts, so as to bypass the corresponding fault current when the corresponding power device experiences thermal runaway.

[0033] Optionally, the power device abuts against the corresponding thermal contact through its own housing or heat sink.

[0034] The heat-controlled switch provided in this application has an elastic conductive structure, one end of which is connected to the inside of a current contact. The elastic conductive structure is provided with a locking end that abuts against one end of a corresponding heat conductor. The other end of the heat conductor is fixed to the inside of the corresponding thermistor. When the heat conductor receives more heat from the corresponding thermistor than a preset amount, it will deform, releasing the locking effect on the corresponding locking end. This causes the other end of the elastic conductive structure to contact or move away from the inside of another current contact, thereby changing the on / off state between the two current contacts, generating a corresponding electrical signal in the connected external circuit, and achieving temperature protection. In other words, this application does not require a power supply and can achieve the corresponding temperature protection with just a single heat-controlled switch. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 and Figure 2 These are schematic diagrams of the thermally controlled switch provided in the embodiments of this application;

[0037] Figure 3a , Figure 3b and Figure 3c They are respectively Figure 1 The diagram shows three specific structural schematics of the thermally controlled switch.

[0038] Figure 4a and Figure 4b They are respectively Figure 2 The diagram shows two specific structural schematics of the thermally controlled switch.

[0039] Figure 5 for Figure 3c The diagram shows the movement direction of the corresponding components during the operation of the thermally controlled switch.

[0040] Figure 6a for Figure 4b A partial structural schematic diagram of the thermally controlled switch as viewed from the side;

[0041] Figure 6b for Figure 4b The diagram shows the movement direction of the corresponding components during the operation of the thermally controlled switch. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0044] This application provides a thermally controlled switch that does not require power supply and can achieve corresponding temperature protection using only a single thermally controlled switch.

[0045] See Figure 1 and Figure 2The thermally controlled switch includes: a flexible conductive structure 100, and at least two current contacts (such as...). Figure 1 and Figure 2 (as shown in 3 and 4), and at least one thermal conductor (such as Figure 1 C1 as shown, or, Figure 2 C1 and C2 shown in the figure) and their corresponding thermal contacts (such as Figure 1 The 1 shown, or, Figure 2 (as shown in 1 and 2); where,

[0046] Of each current contact, at least one serves as a current input contact and another serves as a current output contact, to be connected to the corresponding external circuit.

[0047] One end of the elastic conductive structure 100 is connected to the inside of the current contact 3.

[0048] The elastic conductive structure 100 is provided with a locking end 101, which abuts against the corresponding heat conductor; the other end of the heat conductor is fixed to the inner side of the corresponding thermal contact. Figure 1 Taking a heat conductor C1 as an example, the heat conductor C1 is fixed to the inside of the thermal contact 1 and abuts against the locking end 101. Figure 2 Taking two heat conductors C1 and C2 as an example, heat conductor C1 is fixed to the inside of the thermal contact 1, and heat conductor C2 is fixed to the inside of the thermal contact 2. The two heat conductors C1 and C2 abut against the corresponding locking end 101.

[0049] The heat conductor is used to receive the heat conduction of the corresponding thermal contact, and deforms when the heat received is greater than a preset amount, releasing the locking effect on the corresponding locking end 101, so that the other end of the elastic conductive structure 100 contacts or leaves the inner side of the current contact 4.

[0050] Specifically, in the initial state, the card limit end 101 is in contact with the heat conductor. Figure 1 and Figure 2The following example illustrates a scenario where there is a certain distance between the elastic conductive structure 100 and the current contact 4. In this case, the two current contacts 3 and 4 are not connected, preventing the external circuit from conducting; that is, the thermally controlled switch is in the open state. The outer sides of each thermal contact are brought close to its protected object, such as a power device in a power electronic converter, through welding, bonding, or elastic pressing. This allows them to receive heat conduction from the corresponding power device and sense the operating temperature of the protected object in real time. If any power device connected to a thermal contact experiences thermal runaway, the corresponding thermal conductor deforms due to its own heat exceeding a preset amount, releasing the locking effect on the corresponding locking end 101. This means it detaches from the locking end 101 and no longer presses against it, allowing the elastic conductive structure 100 to move closer to the current contact 4 under its own elastic force until it contacts the inner side of the current contact 4, connecting the two current contacts 3 and 4 and thus enabling the external circuit to conduct. At this point, the thermally controlled switch is in the closed state. Figure 2 As shown in the structure, if the heat on both heat conductors C1 and C2 exceeds their preset amount, both will deform and release the two locking ends 101, which will also cause the thermally controlled switch to enter the closed state.

[0051] In practical applications, the initial state can be configured such that the limiting end 101 abuts against the heat conductor, causing the elastic conductive structure 100 to contact the current contact 4, thus closing the thermally controlled switch. When any protected object experiences thermal runaway, the two current contacts 3 and 4 separate, opening the thermally controlled switch. The principle is similar to the above process and will not be elaborated further here.

[0052] The thermally controlled switch provided in this embodiment, based on the above principle, can generate a corresponding electrical signal in the connected external circuit and achieve temperature protection when the two current contacts change their on / off states. Specifically, in the initial state, when there is a certain distance between the elastic conductive structure 100 and the current contact 4, the corresponding thermally controlled switch can be connected in parallel with the protected object or its power supply. When the thermally controlled switch enters the closed state, it bypasses the fault current of the protected object or short-circuits the power supply of the protected object to prevent the fault current from continuing to flow through the protected object, thus achieving over-temperature protection. In the initial state, when the elastic conductive structure 100 is in contact with the current contact 4, the corresponding thermally controlled switch can be connected in series with the protected object. Then, when the thermally controlled switch enters the open state, it cuts off the connection between the protected object and the power supply, interrupting the fault current of the protected object, thus achieving over-temperature protection. Moreover, this embodiment does not rely on any electronic components or auxiliary power supply; temperature protection can be achieved with only a single thermally controlled switch, requiring no power supply and exhibiting high reliability. In addition, each heat conductor can independently achieve corresponding temperature protection, so this embodiment can simultaneously achieve temperature protection for two power devices, resulting in high utilization.

[0053] Based on the previous embodiment, this embodiment provides several specific implementations of the elastic conductive structure 100 in the thermally controlled switch, see [link to relevant documentation]. Figure 3a , Figure 3b and Figure 3c The elastic conductive structure 100 specifically includes: a conductive structural component 102 and a spring 103; wherein, the first end of the conductive structural component 102 is used to connect to the inner side of the current contact 3; a locking end 101 is provided on the conductive structural component 102, the spring 103 is in a contracted state when the heat conductor abuts against the locking end 101, and the spring 103 is in a relaxed state when the heat conductor releases the locking end 101; the second end of the conductive structural component 102 is used to contact or move away from the inner side of the current contact 4.

[0054] like Figure 3a As shown, the first end of the conductive structure 102 is connected to the inner side of the current contact 3 through a conductive flexible material; the spring 103 is wrapped around the outer side of the conductive structure 102, and one end is fixed in a preset position inside the thermally controlled switch (as shown in the figure, the spring fixing point), and the other end is fixed on the conductive structure 102, so that the conductive structure 102 can move with the spring 103.

[0055] Figure 3a The image shows the structure of the thermally controlled switch in its initial open state. Figure 3b The specific settings of the card limit terminal 101 and the preset position were changed so that the heat-controlled switch is in the closed state in the initial state. Other settings are similar and will not be described in detail.

[0056] and Figure 3a The structure shown differs from that of the external spring 103 and the internal conductive component 102. In practical applications, the conductive component 102 can also be... Figure 3c The structure shown has the spring 103 inside and the conductive structural component 102 outside; specifically as follows: Figure 3c As shown, the conductive structure 102 includes two movably connected cavities, making the length of the conductive structure 102 variable; the spring 103 is disposed inside the conductive structure 102 along the length direction of the conductive structure 102, and the two ends of the spring 103 abut against the inner sides of the two ends of the conductive structure 102 respectively.

[0057] When the thermally controlled switch has more than one internal heat conductor, for example, two, see [reference needed]. Figure 4a and Figure 4b ( Figure 4a exist Figure 3a Using [example] as a basis for demonstration, Figure 4b exist Figure 3cTaking the example of this example, a balancing component and an internal contact D can be added inside the elastic conductive structure 100. The second end of the conductive component 102 contacts or moves away from the inner side of the current contact 4 through the internal contact D. When the internal contact D contacts the current contact 4, the elastic conductive structure 100 enables current flow between the two current contacts 3 and 4. The second end of the conductive component 102 also abuts against the inner side of the balancing component, and each of the outer ends of the balancing component provides a corresponding locking end 101. Specifically, as shown... Figure 4a and Figure 4b As shown, the balancing assembly may include: a balancing fulcrum F and a balancing baffle E; the second end of the conductive structure 102 abuts against one side of the balancing baffle E through the balancing fulcrum F; the other two ends of the balancing baffle E serve as corresponding locking ends 101. Both the conductive structure 102 and the internal contact D are conductors. When the internal contact D contacts the current contact 4, the elastic conductive structure 100 enables current flow between the two current contacts 3 and 4.

[0058] Regardless of the specific implementation of the elastic conductive structure 100 described above, the heat conductor within the thermally controlled switch can be L-shaped, with a portion of it (such as...) Figure 3a , Figure 3b and Figure 4a The horizontal portion shown, or, as Figure 3a and Figure 4b The vertical portion shown is used for deformation and connecting the corresponding thermal contacts, while the other portion (such as...) Figure 3a , Figure 3b and Figure 4a The vertical portion shown, or, as... Figure 3a and Figure 4b The horizontal portion shown is used to abut against the corresponding card limit end 101. In practical applications, the heat conductor can be extended into a Z-shape, so that the part connecting to the corresponding thermal contact is deformed into one end, that is, the middle part is used to deform, and its two ends are used to connect to the corresponding thermal contact and abut against the corresponding card limit end 101, all of which are within the protection scope of this application.

[0059] In practical applications, each heat conductor can be a bimetallic strip, and the two specific metals used are not limited. Any bimetallic strip with temperature-induced deformation characteristics is acceptable, depending on the specific application environment, and all are within the protection scope of this application.

[0060] Figure 3a The working principle of the thermally controlled switch under the structure shown is as follows:

[0061] In the initial state, the vertical part of the heat conductor C1 presses against the locking end 101. When the temperature of the protected object rises to the protection point, the vertical part of the heat conductor C1 deforms, causing the locking mechanism (i.e., the vertical part) to move downward and unlock the locking end 101. This causes the second end of the conductive structure 102 to move to the right under the tension of the spring 103 and contact the current contact 4, short-circuiting the two current contacts 3 and 4. This bypasses the fault current of the protected object, avoiding the risk of the entire device catching fire due to excessive wear of the protected object under abnormal conditions.

[0062] Similarly, the design of spring 103 mechanism can also be adjusted, such as... Figure 3b As shown, before activation, the two current contacts 3 and 4 are short-circuited under the force of spring 103. After unlocking, the current contacts 3 and 4 are separated, realizing the function of protection after opening the circuit.

[0063] Figure 3c The working principle of the thermally controlled switch under the structure shown is as follows:

[0064] In the open state, the conductive component 102 is pressed by the bimetallic strip C1, preventing its second end D from contacting the current contact 4. When heat from an external power device is conducted to the thermistor 1 (e.g., ... Figure 5 As shown in direction a), the heat is conducted to the internal bimetallic strip C1, causing the bimetallic strip C1 to deform due to heat and bend outward (as shown in the direction a). Figure 5 As shown in direction b), it disengages from the conductive structure 102; the conductive structure 102, having lost its blocking effect, moves its second end D under the action of the spring 103 (as shown in direction b). Figure 5 As shown in direction d), the two current contacts 3 and 4 are connected through the contact current contact 4, thereby closing the thermally controlled switch.

[0065] Figure 4b The working principle of the thermally controlled switch under the structure shown is as follows:

[0066] In the off state, its balance baffle E is kept in balance by the bimetallic strips C1 and C2 and the balance fulcrum F, preventing the internal contact D from contacting the current contact 4. Figure 6a Showing for Figure 4b The structure shown, viewed from the left, demonstrates the blocking effect of the bimetallic strip C1 on the balance baffle E. The following describes the process by which the thermally activated contact 1, when heated, causes the thermally controlled switch to close: heat from the external power device is conducted to the thermally activated contact 1 (e.g., ...). Figure 4b and Figure 6b As shown in direction a), the heat is conducted to the internal bimetallic strip C1, causing the bimetallic strip C1 to deform due to heat and bend outward (as shown in the direction a). Figure 4b and Figure 6bAs shown in direction b), it disengages from the balance baffle E; the balance baffle E loses its balance and turns to the right (as shown in the direction b). Figure 4b In the direction shown (c), the blocking effect is lost; the internal contact D moves under the action of spring 103 (as shown). Figure 4b and Figure 6b As shown in direction d), the two current contacts 3 and 4 are connected through the contact current contact 4, thus closing the thermally controlled switch. The process of the thermal contact 2 being activated by heat is similar and will not be described in detail. It can be understood that the two thermal contacts 1 and 2 can be triggered by heat simultaneously, and both can cause their internal contacts D to contact the current contact 4. This structure can continuously monitor the heating of two target power devices. When either power device experiences thermal runaway, heat is transferred to the internal bimetallic strip through the corresponding thermal contact, causing the strip to deform. This leads to the internal balance baffle losing its balance, and under the action of the spring, the internal current contacts close, bypassing the abnormal power device, preventing the thermal runaway from continuing to develop, and avoiding greater safety risks. This structure utilizes a balance component to achieve dual independent temperature sensing functions, making it more cost-effective for engineering applications.

[0067] The working principles of the other implementation forms are similar, and will not be described in detail here.

[0068] The remaining principles can be found in the above embodiments, and will not be repeated here.

[0069] Because the thermally controlled switch provided in the above embodiments has advantages such as low cost, high reliability, and flexible protection location, it can be used in conjunction with power devices in practical applications. For example, a thermally controlled switch with only one thermal contact can be connected in parallel to a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or IGBT (Insulated Gate Bipolar Transistor) unit to form a composite device, avoiding the risk of fire caused by high temperature of the device under abnormal operating conditions. Alternatively, in applications where two power devices are close to each other, they can be combined with a thermally controlled switch containing two thermal contacts for application.

[0070] Based on this, another embodiment of this application also provides a composite power device, which includes: at least one power device and a thermally controlled switch as described in any of the above embodiments; the power device, as the protected object of the corresponding thermally controlled switch, is disposed within a preset range outside the corresponding thermal contact of the thermally controlled switch, and can directly contact the corresponding thermal contact in practical applications.

[0071] The specific structure and working principle of the thermally controlled switch can be found in the above embodiments, and will not be repeated here.

[0072] Another embodiment of this application provides a power electronic converter, comprising: a main circuit and at least one thermally controlled switch as described in any of the above embodiments; the power device in the main circuit serves as the protected object of the corresponding thermally controlled switch and is disposed within a preset range outside the corresponding thermal contact of the thermally controlled switch, and in practical applications, it can be in contact with the corresponding thermal contact through its own housing or heat sink. Alternatively, in practical applications, the main circuit in this power electronic converter can also be directly implemented using the above-described composite power device. The specific structure and working principle of the composite power device can be found in the above embodiments and will not be repeated here.

[0073] The main circuit can be a DC / DC converter, a DC / AC converter, an AC / DC converter, or an AC / AC converter. Alternatively, it can be a two-stage or even multi-stage converter. Its specific topology is not limited and depends on the application environment, and all are within the protection scope of this application.

[0074] Optionally, the thermally controlled switch is connected in series with the corresponding power device through its two current contacts so that the corresponding fault current is cut off when the corresponding power device experiences thermal runaway; or, the thermally controlled switch is connected in parallel with the corresponding power device or its power supply through its two current contacts so that the corresponding fault current is bypassed when the corresponding power device experiences thermal runaway.

[0075] The specific structure and working principle of the thermally controlled switch can be found in the above embodiments, and will not be repeated here.

[0076] Similar or identical parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the description of the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment solution according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0077] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0078] The features described above in the disclosed embodiments can be substituted for or combined with each other to enable those skilled in the art to implement or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thermally controlled switch, characterized in that, include: The structure comprises an elastic conductive structure, at least two current contacts, and at least one heat conductor and its corresponding thermistor; The elastic conductive structure includes: a conductive structural component, a spring, and a balancing assembly; the balancing assembly includes: a balancing fulcrum and a balancing baffle; wherein... The first end of the conductive structural component is connected to the inside of one of the current contacts. The second end of the conductive structural component abuts against one side of the balance baffle through the balance fulcrum; The other two ends of the balance baffle serve as corresponding locking ends, abutting against one end of the corresponding heat conductor; The other end of the heat conductor is fixed to the inner side of the corresponding thermal contact. The heat conductor is used to receive heat conduction from the corresponding thermal contact, and when the heat received is greater than a preset amount, it deforms and detaches from the balance baffle, releasing the limiting effect on the corresponding limiting end, so that the conductive structure moves under the drive of the spring, and the second end of the conductive structure contacts or leaves the inner side of another current contact.

2. The thermally controlled switch according to claim 1, characterized in that, When the heat conductor abuts against the locking end, the spring is in a contracted state; when the heat conductor releases the locking end, the spring is in a relaxed state.

3. The thermally controlled switch according to claim 1, characterized in that, The conductive structural component includes two movably connected cavities, allowing the length of the conductive structural component to be variable; the spring is disposed inside the conductive structural component along its length, with its two ends respectively abutting against the inner sides of both ends of the conductive structural component; or, The first end of the conductive structure is connected to the inner side of the corresponding current contact via a conductive flexible material; the spring is wound around the outer side of the conductive structure, with one end fixed to a preset position inside the thermally controlled switch and the other end fixed to the conductive structure.

4. The thermally controlled switch according to claim 2, characterized in that, The number of thermal contacts is two, and the elastic conductive structure also includes internal contacts; The second end of the conductive structure contacts or moves away from the inner side of the corresponding current contact through the internal contact; when the internal contact contacts the corresponding current contact, the elastic conductive structure enables current to flow between the two current contacts.

5. The thermally controlled switch according to any one of claims 1 to 4, characterized in that, The heat conductor is L-shaped, with one part used for deformation and connection to the corresponding thermal contact, and the other part used to abut against the corresponding locking end; or... The heat conductor is Z-shaped, with its middle portion used for deformation, and its two ends used to connect to the corresponding thermal contacts and abut against the corresponding locking end, respectively.

6. The thermally controlled switch according to claim 5, characterized in that, The heat conductor is a bimetallic sheet.

7. A composite power device, characterized in that, include: At least one power device and a thermally controlled switch as described in any one of claims 1 to 6; The power device is located within a preset range outside the corresponding thermal contact of the thermally controlled switch.

8. The composite power device according to claim 7, characterized in that, The power device abuts against the corresponding thermal contact.

9. A power electronic converter, characterized in that, include: The main circuit and at least one thermally controlled switch as described in any one of claims 1 to 6; The power devices in the main circuit are located within a preset range outside the corresponding thermal contact of the thermally controlled switch; Alternatively, the power device in its main circuit is the composite power device as described in claim 7.

10. The power electronic converter according to claim 9, characterized in that, The thermally controlled switch is connected in series with the corresponding power device through its two current contacts, so that the corresponding fault current is cut off when the power device experiences thermal runaway; or... The thermally controlled switch is connected in parallel with the corresponding power device or its power supply through its two current contacts, so as to bypass the corresponding fault current when the corresponding power device experiences thermal runaway.

11. The power electronic converter according to claim 9 or 10, characterized in that, The power device abuts against the corresponding thermal contact through its own housing or heat sink.

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