Thermal management device and circuit interrupter having same
By introducing phase change material (PCM) and steady-state thermal management device into the circuit breaker, the thermal management problem of solid-state circuit interrupter during transient high-current faults is solved, ensuring safe heat dissipation of power electronic modules under transient and steady-state conditions.
Patent Information
- Application Number
- CN202510753104.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-06-07
- Filing Date
- 2025-06-06
- Publication Date
- 2025-12-09
AI Technical Summary
Insufficient thermal management of solid-state circuit breakers during transient high-current faults can lead to overheating of power electronic modules and damage to circuit breakers.
Phase change material (PCM) is used as a transient fault thermal management device to provide a transient heat flow path. Combined with a steady-state thermal management device, including fins and a base, it effectively dissipates heat during faults and normal operation, respectively.
During transient high-current faults, the PCM stores heat in the form of latent heat to keep the temperature of the power electronic module within a safe range, preventing damage, while maintaining the thermal management efficiency for normal operation.
Smart Images
Figure CN121096799A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to a thermal management device for a circuit breaker, and more particularly to a thermal management device including a phase change material (PCM) for heat dissipation during transient high current faults. Background Technology
[0002] Circuit interrupters, such as, but not limited to, circuit breakers, are typically used to protect circuit systems from damage caused by overcurrent conditions, such as overloads, short circuits, or other fault conditions, such as arcing or grounding faults. Solid-state circuit interrupters use solid-state components, such as power electronic modules containing semiconductor devices, to connect and disconnect current flowing from the power source to the load. While solid-state devices are significantly faster than conventional electromechanical devices, their thermal capacity is much smaller due to their compact and lightweight design. Therefore, solid-state devices require thermal management devices to dissipate heat quickly during operation. However, during transient high-current faults (e.g., but not limited to, motor starting currents, overload faults, etc.), the temperature of the power electronic module may suddenly rise above its maximum permissible temperature. This sudden rise can cause thermal management devices to fail and lead to damage to the power electronic module and / or the circuit breaker.
[0003] There is still considerable room for improvement in thermal management devices used in circuit breakers. Summary of the Invention
[0004] A circuit breaker configured to connect between a power source and a load and to interrupt the flow of current to the load in the event of a fault satisfies these and other requirements. The circuit breaker includes: a power electronic module connected between the power source and the load, configured to switch off during a fault to interrupt the flow of current to the load; a transient fault thermal management device including a housing with an inner cavity and a phase change material (PCM) disposed within the inner cavity, the transient fault thermal management device being configured to provide a transient heat flow path via which heat is dissipated from the power electronic module during a fault, the transient heat flow path including the PCM; and a steady-state thermal management device including a base, a body extending upward from the base, and a plurality of fins extending downward from the base, the body being attached to the power electronic module on one side and surrounded by the housing, the steady-state thermal management device being configured to provide a steady-state heat flow path via which heat is dissipated from the power electronic module during normal operation, the steady-state heat flow path not including the PCM.
[0005] Another example embodiment provides a circuit breaker configured to connect between a power source and a load and to interrupt the current flowing to the load in the event of a fault. The circuit breaker includes: a steady-state thermal management device comprising a base and a plurality of fins extending downward from the base; a power electronic module horizontally disposed on a top surface of the base, the power electronic module being connected between the power source and the load, and the power electronic module being configured to switch off during a fault to interrupt current flowing to the load; and a transient fault thermal management device comprising a housing having an inner cavity, an opening in the housing, and a phase change material (PCM) disposed within the inner cavity, the housing being configured to surround an edge of the base of the steady-state thermal management device, the opening in the housing extending upward from the top surface of the housing, the PCM being inserted through the opening in the housing, wherein the steady-state thermal management device provides a steady-state heat flow path through which heat is dissipated from the power electronic module during normal operation, the steady-state heat flow path not including the PCM, and wherein the transient fault thermal management device provides a transient heat flow path through which heat is dissipated from the power electronic module during a fault, the transient heat flow path including the PCM.
[0006] Another example embodiment provides a thermal management device for use in a circuit breaker, comprising a power electronic module and configured to connect between a power source and a load and to interrupt current flow to the load in the event of a fault. The thermal management device includes: a transient fault thermal management device comprising a housing having an inner cavity and a phase change material (PCM) disposed within the inner cavity, the transient fault thermal management device being configured to provide a transient heat flow path via which heat is dissipated from the power electronic module during a fault, the transient heat flow path including the PCM; and a steady-state thermal management device comprising a base and a plurality of fins extending downward from the base, the base being configured to attach to the power electronic module and the base being surrounded by the housing, the steady-state thermal management device being configured to provide a steady-state heat flow path via which heat is dissipated from the power electronic module during normal operation, the steady-state heat flow path not including the PCM. Attached Figure Description
[0007] A full understanding of the invention can be obtained from the following description of preferred embodiments when read in conjunction with the accompanying drawings, wherein:
[0008] Figure 1 This is an internal view of a circuit interrupter with an exemplary transient fault thermal management device, according to an example embodiment of the concept of this disclosure;
[0009] Figure 2 It has Figure 1 Rear view of the circuit interrupter of the transient fault thermal management device;
[0010] Figure 3 yes Figure 1 Top perspective view of the transient fault thermal management device;
[0011] Figure 4 yes Figure 1 A cross-sectional view of the circuit interrupter taken along line AA.
[0012] Figure 5 This illustrates how the temperature of materials in a conventional thermal management device rises with the input of heat;
[0013] Figure 6 The diagram shows that as the temperature of a phase change material (PCM) increases with the input heat;
[0014] Figure 7 The illustration depicts temperature variations in a power electronic module with a transient fault thermal management device including a PCM, and those without. Figure 1 Simulation results of temperature changes in the power electronic module of a transient fault thermal management device;
[0015] Figure 8 An internal view of a circuit interrupter having another exemplary transient fault thermal management device, according to an example embodiment of the concept of this disclosure, is shown; and
[0016] Figure 9 It shows Figure 8 Exploded view of a circuit interrupter. Detailed Implementation
[0017] Directional phrases used herein, such as, for example, left, right, front, back, up, down, and their derivatives, relate to the orientation of the elements shown in the accompanying drawings and do not limit the claims unless expressly stated herein.
[0018] As used in this article, the expression "coupled" of two or more components should refer to components that are directly connected together or connected through one or more intermediate components.
[0019] Figure 1-4 An internal view of a circuit interrupter 1 and its components according to an example embodiment of the concept of this disclosure is shown. Although Figure 1A circuit breaker 1 without a housing is shown, but it should be understood that this is for illustrative purposes only, and the circuit breaker 1 and its components are housed within a housing. The circuit breaker 1 (e.g., but not limited to a circuit breaker) is electrically connected between a power source (e.g., a utility) via a line conductor 2 and between a load and a load via a load conductor 8. The circuit breaker 1 is configured to trip or switch to open to interrupt the current flowing to the load, for example, in the event of a fault (e.g., but not limited to an overcurrent condition), thereby protecting the load, the circuit system associated with the load, and the components within the circuit breaker 1. The circuit breaker 1 may be a single-phase circuit breaker or may employ any other number of phase circuit breakers without departing from the scope of this disclosure.
[0020] Circuit breaker 1 includes a power electronic module 10, a steady-state thermal management device 20, and a transient fault thermal management device 30. Circuit breaker 1 may also include sensors (e.g., but not limited to current sensors, temperature sensors, etc.), control circuitry (e.g., microcontrollers, CPUs, etc.), and power supply circuitry for supplying power to the electrical components within circuit breaker 1. Power electronic module 10 is connected to line conductor 2 via bus 3 and to flexible heat sink 5 via bus 4. Flexible heat sink 5 is connected to separable contact 6, which in turn is connected to load conductor 8 and a load (not shown). Separable contact 6 provides electrical isolation when the mechanical switch of circuit breaker 1 is switched. Power electronic module 10 may include, for example, but not limited to, solid-state switching elements (e.g., but not limited to, metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs)). Solid-state switching elements are configured to conduct and cut off (i.e., open and close) to allow or interrupt current flow to the load. Power electronic module 10 may extend vertically upward relative to steady-state thermal management device 20.
[0021] The steady-state thermal management device 20 is a heat sink configured to absorb heat from the power electronics module 10 and dissipate it to the surrounding environment and / or coolant. It may be made of, for example, aluminum, but is not limited to, and includes a body 22, a base 24, and a plurality of fins 26. The body 22 may include, for example, an aluminum block extending vertically upward from the base 24, but is not limited to, it. The body 22 is configured to attach to and support the power electronics module 10 on one side 23. The fins 26 extend vertically downward from the base 24 and are configured to provide a larger surface area for heat dissipation. The fins 26 may contain coolant. During normal operation, the steady-state thermal management device 20 provides a steady-state heat flow path 37 from the power electronics module 10 to the body 22 of the steady-state thermal management device 20, to the base 24, and to the surrounding environment or coolant (power electronics module 20 → body 22 of steady-state thermal management device 20 → base 24 of steady-state thermal management device 20 → surrounding environment or coolant).
[0022] Transient fault thermal management device 30 is configured to provide a transient heat flow path 38 (see below) during transient power peaks (e.g., but not limited to, motor starting current, overload faults, etc.). Figure 4 It includes a housing 32 and one or more legs 35. The housing 32 is made of plastic, such as, but not limited to, thermosetting plastic. The housing 32 has an inner cavity configured to receive PCM via one or more housing openings 34 during manufacturing or use. PCM is a substance that absorbs or releases a large amount of energy in the form of latent heat during a phase change (e.g., but not limited to, from a solid to a liquid state). The housing 32 is configured to surround the body 22 of the thermal management device 20 except for one side 23. One or more legs 35 extend upward from one or more bottom edges of the housing 32. Each leg 35 may include a housing opening 34 through which PCM is received or refilled into the inner cavity. The one or more legs 35 are spaced apart from the housing 32 to form a space therebetween to provide sufficient space for the expansion of the body 22 of the steady-state thermal management device 20 when heat is input. By including the PCM within the housing 32 and attaching the transient fault thermal management device 30 to the side of the steady-state thermal management device 20 opposite to the side 23 where the power electronics module 10 is attached, the PCM creates a transient heat flow path 38 (power electronics module 10 → main body 22 of steady-state thermal management device 20 → housing 32 of transient fault thermal management device 30 → ambient environment or coolant), through which heat flows and dissipates during transient high-current faults.
[0023] In other words, the transient fault thermal management device 30 utilizes the latent heat capacity of the PCM to maintain the temperature of the power electronic module 10 within the maximum permissible temperature range during transient high-current faults. For example... Figure 6 As shown, when the PCM reaches its melting temperature at 42, it undergoes a phase change process 40. The PCM begins to melt and stores heat as latent heat, with little or no temperature rise. The temperature only rises when the phase change is complete at 44. Therefore, by selecting a PCM with a melting temperature lower than the maximum permissible temperature of the power electronic module 20, the PCM ensures that during transient high-current faults, the temperature of the power electronic module 20 remains below its maximum permissible temperature when it undergoes a phase change. This latent heat capacity is not present in conventional heat sink heat conduction materials (e.g., but not limited to aluminum), which store heat as sensible heat, causing the temperature to rise steadily with increasing heat, such as... Figure 5 As shown. Reference Figure 7 The differences in temperature rise between traditional heatsink heat conduction materials and PCM will be discussed in further detail.
[0024] Furthermore, heat will only flow through the PCM via transient heat flow path 38 during transient peak power periods, and therefore the PCM has little or no effect on the maximum temperature of the power electronics module 10 during normal operation. In other words, adding the PCM within the housing 32 does not increase the thermal resistance in the steady-state heat flow path 37, and therefore the maximum temperature during normal operation is not affected by the PCM. This is superior to existing PCM thermal management devices, which include a PCM connected in series with a heat sink, requiring heat to flow through the PCM to reach the heat sink. This heat flow path, requiring heat to flow through a PCM connected in series with a heat sink, increases the thermal resistance and maximum temperature of the power electronics module during normal operation.
[0025] Furthermore, by adding the PCM within the cavity of the housing 32 instead of within the steady-state thermal management device 20, the transient failure thermal management device 30 ensures that it does not negatively impact the thermal and structural performance of the steady-state thermal management device 20. For example, some existing radiators contain the PCM within their fins. This prevents air or coolant flow through the fins and thus inhibits free or forced convection, potentially causing radiator failure. Additionally, volume changes within the PCM cause stress on the fins, making the radiator more susceptible to failure. Moreover, the molten PCM can resolidify within the housing 32 during steady-state operation, thus eliminating the need for continuous solder flow or circulation. If necessary, the solder can be replaced through the housing opening 34.
[0026] Figure 7 The diagram illustrates temperature variations 52 of a power electronic module with transient fault thermal management devices and a module without such devices. Figure 1-4 The simulation results are for the temperature change 50 of the power electronic module in the transient fault thermal management device 30. For the simulation, boundary conditions for the transient fault thermal management device 30 are defined to specify the heat loss of the power electronic module 10 as heat flux, the melting and solidification models of the phase change, and the heat transfer coefficient applied to the steady-state thermal management device 20, in order to simulate forced convection. The melting and solidification models utilize enthalpy characteristics to simulate the phase change process. During steady state, in the steady-state heat flow path 37, heat flows directly from the power electronic module 10 to the steady-state thermal management device 20, and also flows to the environment or coolant (see...). Figure 4 During the transient power peak, the PCM reaches its melting point and begins to melt, absorbing latent heat at a constant temperature (e.g., but not limited to 130°C). Figure 7The diagram illustrates the power electronic module 10 reaching peak power at time zero, 3000 seconds, and 6000 seconds. When the PCM absorbs peak power, it begins to melt and absorbs heat as latent heat, thus maintaining the temperature of the power electronic module 10 near, for example, but not limited to, a melting temperature of 130°C. The temperature 50 of a power electronic module used with a heat sink having conventional thermally conductive materials would rise above the maximum permissible temperature (e.g., but not limited to 150°C) during each peak power period, potentially damaging the power electronic module. However, the temperature 52 of the power electronic module 10 used with the transient fault thermal management device 30 of the present invention remains below the maximum permissible temperature during peak power, thereby protecting the power electronic module 10 from sudden power spikes.
[0027] Figure 8 and Figure 9 An internal view of an exemplary circuit breaker 100 with a transient fault thermal management device 130, according to a non-limiting example embodiment of the concept of this disclosure, is shown. Apart from the structure and / or arrangement of the power electronics module 110, the steady-state thermal management device 120, and the transient fault thermal management device 130, the circuit breaker 100 is... Figure 1-4 The circuit breaker 1 is similar. Therefore, for the sake of brevity, repeated descriptions of similar features and components are omitted. Unlike the steady-state thermal management device 20, the steady-state thermal management device 120 does not include a main body portion extending vertically upward from the base 122 and supporting the power electronics module 110. Therefore, the power electronics module 110 rests horizontally on the top surface of the base 122 of the steady-state thermal management device 120. Furthermore, the transient thermal management device 130 includes one or more legs 135 extending upward from the top surface of the housing 132. Each leg 135 includes a housing opening 134. In addition, the housing 132 has a frame shape, which is configured to surround the outer edge of the base 122 of the steady-state thermal management device 120. During steady state, the steady-state thermal management device 120 provides a steady-state heat flow path 137 directly from the power electronics module 110 via the fins 124 to the surrounding environment. During transient power peaks, the transient fault thermal management device 130 provides an alternative heat flow path 138 from the power electronics module 110 through the base 122 of the steady-state thermal management device 120 and the PCM to the surrounding environment. Figure 8-9 The structure and configuration of the power electronics module 110, steady-state thermal management device 120 and transient fault thermal management device 130 are for illustrative purposes only and can therefore be adjusted or changed to suit the internal design and available space within the circuit breaker.
[0028] While specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and alternatives to these details can be developed based on the overall teachings of this disclosure. Therefore, the specific arrangements of this disclosure are intended for illustrative purposes only and do not limit the scope of the conception of this disclosure, which is given by the full scope of the appended claims and any and all their equivalents.
Claims
1. A circuit breaker configured to connect between a power source and a load and to interrupt current flowing to the load in the event of a fault, the circuit breaker comprising: A power electronic module is connected between the power source and the load, and the power electronic module is configured to switch off during the fault to interrupt the current flowing to the load; A transient fault thermal management device includes a housing having an inner cavity and a phase change material (PCM) disposed within the inner cavity. The transient fault thermal management device is configured to provide a transient heat flow path through which heat is dissipated from the power electronics module during the fault, the transient heat flow path including the phase change material. as well as A steady-state thermal management device includes a base, a body extending upward from the base, and a plurality of fins extending downward from the base. The body is attached to the power electronics module on one side and is surrounded by the housing. The steady-state thermal management device is configured to provide a steady-state heat flow path through which heat is dissipated from the power electronics module during normal operation. The steady-state heat flow path does not include the phase change material.
2. The circuit breaker according to claim 1, wherein, When the melting temperature is reached, the phase change material begins to melt and absorbs heat in the form of latent heat at a constant temperature, creating the transient heat flow path.
3. The circuit breaker according to claim 2, wherein, The latent heat capacity of the phase change material allows it to resist temperature changes during the fault and provides a lower peak temperature compared to the peak temperature obtained by a thermal management device without a phase change material.
4. The circuit breaker according to claim 2, wherein, The constant temperature is below the maximum permissible temperature of the power electronic module.
5. The circuit breaker according to claim 1, wherein, The phase change material does not affect the maximum temperature of the power electronic module during normal operation.
6. The circuit breaker according to claim 5, wherein, Heat flows through the phase change material only during the aforementioned failure.
7. The circuit breaker according to claim 5, wherein, The phase change material does not increase the thermal resistance in the steady-state heat flow path during normal operation.
8. The circuit breaker according to claim 1, wherein, The phase change material is selected to have a melting temperature lower than the maximum permissible temperature of the power electronic module, so that the temperature of the power electronic module is maintained within the maximum permissible temperature when the phase change material melts during the fault.
9. The circuit breaker according to claim 1, wherein, The transient fault thermal management device further includes one or more legs extending upward from one or more bottom edges of the housing, each leg having a housing opening through which the phase change material is received into the inner cavity.
10. The circuit breaker according to claim 9, wherein, The housing is configured to surround the body of the steady-state thermal management device except for the side mentioned above, and wherein the one or more legs and the housing are separated to form a space therebetween to allow the body of the steady-state thermal management device to expand when heat is input.
11. The circuit breaker according to claim 1, wherein, The phase change material includes a tin-bismuth-indium alloy.
12. The circuit breaker according to claim 1, wherein, The fins of the steady-state thermal management device do not include phase change materials.
13. The circuit breaker according to claim 1, wherein, The power electronic module includes solid-state switching elements.
14. A circuit breaker configured to connect between a power source and a load and to interrupt current flowing to the load in the event of a fault, the circuit breaker comprising: A steady-state thermal management device, comprising a base and a plurality of fins extending downward from the base; A power electronic module, horizontally disposed on the top surface of the base, is connected between the power source and the load, and is configured to switch off during the fault to interrupt the current flowing to the load; as well as A transient fault thermal management device includes a housing with an inner cavity, a housing opening, and a phase change material (PCM) disposed within the inner cavity. The housing is configured to surround the edge of a base of the steady-state thermal management device. The housing opening extends upward from the top surface of the housing, and the PCM is inserted through the housing opening. The steady-state thermal management device provides a steady-state heat flow path through which heat is dissipated from the power electronic module during normal operation. This steady-state heat flow path does not include the phase change material. The transient fault thermal management device provides a transient heat flow path, through which heat is dissipated from the power electronic module during the fault, and the transient heat flow path includes the phase change material.
15. The circuit breaker according to claim 14, wherein, When the melting temperature is reached, the phase change material begins to melt and absorbs heat in the form of latent heat at a constant temperature, creating the transient heat flow path.
16. The circuit breaker according to claim 15, wherein, The latent heat capacity of the phase change material allows it to resist temperature changes during the fault and provides a lower peak temperature compared to the peak temperature obtained by a thermal management device without a phase change material.
17. The circuit breaker according to claim 15, wherein, The constant temperature is below the maximum permissible temperature of the power electronic module.
18. The circuit breaker according to claim 14, wherein, The phase change material does not affect the maximum temperature of the power electronic module during normal operation.
19. The circuit breaker according to claim 18, wherein, Heat flows through the phase change material only during the fault, and the phase change material does not increase the thermal resistance in the steady-state heat flow path during normal operation.
20. A thermal management device for use in a circuit breaker, comprising a power electronic module and configured to connect between a power source and a load and to interrupt current flowing to the load in the event of a fault, the thermal management device comprising: A transient fault thermal management device includes a housing having an inner cavity and a phase change material (PCM) disposed within the inner cavity. The transient fault thermal management device is configured to provide a transient heat flow path through which heat is dissipated from the power electronics module during the fault, the transient heat flow path including the phase change material. as well as A steady-state thermal management device includes a base and a plurality of fins extending downward from the base, the base being configured to be attached to the power electronics module and the base being surrounded by the housing, the steady-state thermal management device being configured to provide a steady-state heat flow path through which heat is dissipated from the power electronics module during normal operation, the steady-state heat flow path not including the phase change material.