Thermomechanical frame for solid state circuit breaker

Abstract

Thermal management structures and techniques for cooling solid state circuit breakers are provided. For example, a circuit breaker includes an integrated heat sink configured to absorb and dissipate heat from electronic components of the circuit breaker using a combination of conduction and convection.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 402,058, filed on August 29, 2022, the disclosure of which is incorporated herein by reference. Background Art

[0003] The present disclosure generally relates to thermal management techniques for circuit breakers, and specifically to thermal management of solid-state circuit breakers. Circuit breakers are essential components in power distribution systems. For example, circuit breakers are typically disposed in a distribution board (e.g., a circuit breaker panel) that distributes and feeds utility power to multiple downstream branch circuits within a given building or housing structure. Each circuit breaker is connected between the utility power feed and a corresponding one of the branch circuits to protect the branch circuit conductors and electrical loads on the branch circuit. Conventional circuit breakers include electromechanical circuit breakers having a mechanical switch that can be opened and closed manually, or automatically tripped by: (i) operation of an electromagnetic actuator (e.g., a solenoid) in response to a large current surge (short circuit) and (ii) operation of a thermomechanical actuator (e.g., a bimetallic element) in response to a less extreme but longer-term overcurrent condition. Due to the electromechanical construction, conventional electromechanical circuit breakers can be slow to react to fault conditions and typically require at least several milliseconds to isolate the fault condition, which is undesirable because such delays can increase the risk of dangerous fires, damage to electrical equipment, and arc flash, which can occur at the short circuit location when a bolt fault is not isolated quickly enough.

[0004] On the other hand, a solid-state circuit breaker can implement a solid-state alternating current (AC) switch to interrupt the AC current, and implement associated electronics to control the operation of the solid-state AC switch. Compared with traditional electromechanical circuit breakers, solid-state circuit breakers provide significantly faster reaction times (e.g., on the order of hundreds of microseconds) to isolate fault conditions, such as short circuit conditions and overcurrent conditions. However, due to the operation of the high-voltage solid-state AC switch and associated control electronics, solid-state circuit breakers generate a large amount of heat, which can cause relatively large amounts of thermal stress to solid-state components. Such thermal stress can damage solid-state components or otherwise shorten the service life of solid-state components. Therefore, an effective thermal design of a solid-state circuit breaker is desired to avoid overheating and thermal stress on solid-state electronic components. Summary of the invention

[0005] Exemplary embodiments of the present disclosure include thermal management structures and techniques for cooling solid-state circuit breakers. For example, exemplary embodiments include a circuit breaker that includes an integrated heat sink configured to absorb and dissipate heat from electronic components of the circuit breaker using a combination of conduction and convection.

[0006] Another exemplary embodiment includes a circuit breaker including an electronic assembly and an integrated heat sink. The electronic assembly includes an electronic component. The integrated heat sink is configured to absorb and dissipate heat from the electronic component of the electronic assembly. The integrated heat sink includes a first cooling plate and a second cooling plate. At least a portion of the electronic assembly is disposed between the first cooling plate and the second cooling plate so that the first cooling plate and the second cooling plate absorb heat generated by the electronic component through conduction.

[0007] Another exemplary embodiment includes a DIN rail mount circuit breaker including an integrated heat sink configured to absorb and dissipate heat from electronic components of the DIN rail mount circuit breaker. The integrated heat sink includes a first extension portion extending from a plastic housing of the DIN rail mount circuit breaker and configured to be in thermal contact with the DIN rail mount to dissipate heat from the integrated heat sink to the DIN rail mount.

[0008] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, an integrated heat sink is disposed within a plastic housing of the circuit breaker, and the integrated heat sink includes at least one extension portion extending from the plastic housing and configured to dissipate heat to an external environment.

[0009] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, the at least one extension portion comprises an external cooling fin structure configured to dissipate heat to external ambient air by convective heat transfer.

[0010] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, the at least one extension portion includes a rail contact structure configured to couple to a circuit breaker mounting rail and dissipate heat to the circuit breaker mounting rail by conductive heat transfer.

[0011] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, the integrated heat sink comprises a unitary molded element formed of a thermally conductive material, such as a unitary molded aluminum structure.

[0012] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, a circuit breaker includes an electronic assembly including a first substrate and a second substrate. The electronic assembly includes: (i) a plurality of solid-state switching devices mounted on the first substrate and configured to implement a solid-state AC switch; and (ii) an integrated circuit (IC) chip mounted on the second substrate and configured to implement a control circuit system for controlling the operation of the solid-state AC switch. The integrated heat sink includes a first cooling plate and a second cooling plate. The first substrate and the second substrate of the electronic assembly are disposed between the first cooling plate and the second cooling plate. The first cooling plate and the second cooling plate are configured to absorb heat generated by the electronic assembly by conduction.

[0013] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, a plurality of solid-state switching devices are mounted on a front surface of a first substrate. An IC chip is mounted on a front surface of a second substrate. A first cooling plate is thermally coupled to a back surface of the first substrate, the back surface being opposite to the front surface of the first substrate. A second cooling plate is thermally coupled to a back surface of the IC chip.

[0014] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, an electronic assembly includes a first wire connector terminal coupled to a first substrate and a second wire connector terminal coupled to the first substrate. The first wire connector terminal and the second wire connector terminal are configured to absorb heat from the first substrate by conduction and dissipate the heat to an external environment by conduction of the heat to electrical wiring connected to the first wire connector terminal and the second wire connector terminal.

[0015] In another exemplary embodiment that may be combined with one or more of the embodiments of the preceding paragraphs, the first cooling plate and the second cooling plate are configured to absorb heat generated by the electronic components and create a temperature difference between the first cooling plate and the second cooling plate, the temperature difference causing a convective air flow within the housing of the circuit breaker to circulate heated air to other components of the integrated heat sink and causing convective heat transfer from the heated air to other components of the integrated heat sink.

[0016] Other embodiments are described in the following detailed description of exemplary embodiments, which is to be read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A , Figure 1B , Figure 1C , Figure 1D , Figure 1E and Figure 1Fis a schematic perspective view of a solid-state circuit breaker including an integrated heat sink according to an exemplary embodiment of the present disclosure.

[0018] Figure 2A , Figure 2B and Figure 2C is a schematic perspective view of a solid state circuit breaker coupled to a mounting rail according to an exemplary embodiment of the present disclosure.

[0019] Figure 3 The electronic components of an intelligent solid-state circuit breaker according to an exemplary embodiment of the present disclosure are schematically illustrated.

[0020] Figure 4 Embodiments of solid-state AC switches that may be implemented in solid-state circuit breakers according to exemplary embodiments of the present disclosure are schematically illustrated.

[0021] Figure 5 An embodiment of a solid-state AC switch that may be implemented in a solid-state circuit breaker according to another exemplary embodiment of the present disclosure is schematically illustrated. DETAILED DESCRIPTION

[0022] Embodiments of the present disclosure will now be described in further detail with respect to a solid-state circuit breaker including an integrated heat sink configured to absorb and dissipate heat from electronic components of the solid-state circuit breaker using a combination of conduction and convection. Exemplary embodiments of the present disclosure include techniques for thermal management of a solid-state circuit breaker including, for example, a high power solid-state switching device for implementing a solid-state AC switch, and control electronics for controlling operation of the solid-state AC switch and implementing smart circuit breaker functionality.

[0023] It should be understood that the various features shown in the drawings are schematic illustrations that are not drawn to scale. In addition, throughout the drawings, the same or similar reference numerals are used to represent the same or similar features, elements or structures, and therefore, a detailed explanation of the same or similar features, elements or structures will not be repeated for each drawing. Further, the term "exemplary" as used herein means "serving as an example, instance or illustration". Any embodiment or design described herein as "exemplary" should not be construed as being more preferred or advantageous over other embodiments or designs.

[0024] Further, it should be understood that the phrase "configured to" as used in connection with circuits, structures, elements, components, etc. that perform one or more functions or otherwise provide some functionality is intended to cover embodiments in which the circuits, structures, elements, components, etc. are implemented in hardware, software and / or a combination thereof, as well as in embodiments that include hardware, where the hardware may include discrete circuit elements (e.g., transistors, inverters, etc.), programmable elements (e.g., application specific integrated circuit (ASIC) devices, field programmable gate array (FPGA) devices, etc.), processing devices (e.g., central processing unit (CPU) devices, graphics processing unit (GPU) devices, microcontroller devices, etc.), one or more integrated circuits and / or a combination thereof. Thus, by way of example only, when a circuit, structure, element, component, etc. is defined as being configured to provide a specific functionality, this is intended to cover, but not be limited to, embodiments in which the circuit, structure, element, component, etc. is comprised of elements, processing devices and / or integrated circuits that enable it to perform the specific functionality when in an operational state (e.g., connected or otherwise deployed in a system, powered on, receiving input and / or generating output), and to cover embodiments when the circuit, structure, element, component, etc. is in a non-operational state (e.g., not connected or otherwise deployed in a system, not powered on, not receiving input and / or not generating output) or in a partially operational state.

[0025] Figure 1A , Figure 1B , Figure 1C , Figure 1D , Figure 1E and Figure 1F is a schematic perspective view of a solid-state circuit breaker including an integrated heat sink according to an exemplary embodiment of the present disclosure. Specifically, Figures 1A to 1F A solid-state circuit breaker 100 is collectively illustrated according to an exemplary embodiment of the present disclosure, wherein the solid-state circuit breaker 100 includes an electronics assembly 110 , an integrated heat sink element 120 , and a housing 130 (eg, a plastic exterior clamshell housing). Figure 1A 1 is an exploded view showing the electronic assembly 110 and the integrated heat sink element 120 separately, and Figure 1B is a perspective view of an assembled configuration of electronic assembly 110 and integrated heat sink element 120 . Figure 1C is another perspective view of a separate integrated heat sink element 120, and Figure 1D is another perspective view of the assembled configuration of the electronic assembly 110 and the integrated heat sink element 120. Finally, Figure 1E and Figure 1F Different perspective views of the solid-state circuit breaker 100 are shown, with the housing 130 (e.g., a plastic outer clamshell housing) shown in phantom. Figure 1E and Figure 1FOther components of the solid-state circuit breaker 100 are shown, including, but not limited to, a manual switch 132 and a mounting clip 134. The manual switch 132 allows a user to manually switch the solid-state circuit breaker 100 to an ON state or an OFF state, or to otherwise manually reset the solid-state circuit breaker 100 after the circuit breaker automatically trips in response to a detected fault condition (e.g., a short circuit). As explained in further detail below, the mounting clip 134 is configured to securely mount the solid-state circuit breaker 100 to, for example, a mounting rail.

[0026] For example, Figure 1A , Figure 1B and Figure 1D As shown together, the electronic assembly 110 includes a first substrate 111, a second substrate 112, a plurality of solid-state switching devices 113, a plurality of electronic integrated circuit (IC) chips 114, a first wire terminal connector 115, and a second wire terminal connector 116. In some embodiments, the first substrate 111 and the second substrate 112 include printed circuit boards (PCBs) on which various chips and electronic devices are mounted. Specifically, the solid-state switching device 113 is mounted on the front surface of the first substrate 111, and the electronic IC chip 114 is mounted on the front surface of the second substrate 112.

[0027] In some embodiments, the solid-state switch device 113 includes two or more high-power solid-state switch devices that are operably connected to implement a solid-state bidirectional switch. In some embodiments, the solid-state switch device 113 includes a power metal oxide semiconductor field effect transistor (MOSFET) device (e.g., a separate MOSFET chip), but other types of solid-state switch devices may also be implemented, as discussed in further detail below. The electronic IC chip 114 collectively includes a control circuit system for controlling the operation of the solid-state AC switch and performing other control functions for implementing the intelligent solid-state circuit breaker. For example, the electronic IC chip 114 includes one or more microprocessors, switch control circuit systems, sensor circuit systems, and other circuit systems for implementing the intelligent functions of the solid-state circuit breaker 100.

[0028] The first wire terminal connector 115 and the second wire terminal connector 116 are configured to enable electrical wiring to be connected to the solid-state circuit breaker 100. For example, Figure 1A , Figure 1B and Figure 1DAs shown, the first wire 117 is connected to the first wire terminal connector 115, and the second wire 118 is connected to the second wire terminal connector 116. In an exemplary embodiment, the first wire 117 can be a line hot wire (which is coupled to the line phase of the utility power), and the second wire 118 can be a load hot wire that feeds AC power to a branch circuit or load device. For ease of illustration, the neutral wire connection to the solid-state circuit breaker 100 is not shown in the drawings, although in fact the neutral tail will be coupled to the neutral node of the circuit system (electronic IC chip 114) mounted on the front surface of the second substrate 112. As further shown, the first wire terminal connector 115 includes an extended connection tab 115-1 that is connected to the first substrate 111 to provide an electrical connection to the line side node of the solid-state AC switch formed by the solid-state switch device 113, and the second wire terminal connector 116 includes an extended connection tab 116-1 that is connected to the first substrate 111 to provide an electrical connection to the load side node of the solid-state AC switch formed by the solid-state switch device 113. As explained in further detail below, the first and second wire terminal connectors 115 , 116 and the first and second wires 117 , 118 connected thereto provide a mechanism for efficient convective and conductive heat transfer to cool the electronic assembly 110 .

[0029] For example, Figure 1A , Figure 1B , Figure 1C and Figure 1DAs shown together, the integrated heat sink 120 includes a first plate 121, a second plate 122 (alternatively referred to herein as a first cooling plate and a second cooling plate), a first cooling fin structure 123, a second cooling fin structure 124, a third cooling fin structure 125, and a rail contact structure 126 (alternatively, a base structure 126). In some embodiments, the integrated heat sink 120 includes an integral molded element formed of any suitable thermally conductive material such as a metallic material. For example, in an exemplary embodiment, the integrated heat sink 120 includes a molded aluminum structure. The integrated heat sink 120 can be composed of other suitable materials or alloys having sufficient thermal conductivity for a given application. The integrated heat sink 120 includes a thermally conductive mechanical architecture that is configured to absorb and dissipate heat from the electronic components of the solid-state circuit breaker 100 using a combination of conduction and convection. Specifically, the integrated heat sink 120 is configured to absorb heat and dissipate heat from the electronic assembly 110 using a combination of conduction and convection. In addition, the assembled configuration of the electronic assembly 110 and the integrated heat sink 120 includes a thermally conductive mechanical architecture that is configured to absorb and dissipate heat from the electronic components of the solid-state circuit breaker 100 using a combination of conduction and convection. The term "conduction" as used herein generally refers to the transfer of heat (thermal energy flow) from one solid to another. The term "convection" (or convective heat transfer) as used herein generally refers to the transfer of heat from one point to another due to the movement of a gas (e.g., air).

[0030] For example, Figure 1B and Figure 1D As shown, in an exemplary assembly configuration, the first substrate 111 and the second substrate 112 of the electronic assembly 110 are disposed (sandwiched) between a first cooling plate 121 and a second cooling plate 122, wherein the first wire terminal connector 115 is disposed adjacent to the first cooling fin structure 123, and the second wire terminal connector 116 is disposed adjacent to the second cooling fin structure 124. In some embodiments, the first wire terminal connector 115 and the second wire terminal connector 116 include elongated metal structures (e.g., elongated cylindrical structures) extending adjacent to most or all of the length or height of the first cooling fin structure 123 and the second cooling fin structure 124, respectively.

[0031] In some embodiments, the first cooling plate 121 is thermally coupled to the back surface of the first substrate 111 with a thermal interface material (TIM) material disposed therebetween to enhance the transfer of heat (generated by the high power solid state switching device 113) from the first substrate 111 to the first cooling plate 121. Further, in some embodiments, the second cooling plate 122 is thermally coupled (via a TIM layer) to the back surface of the electronic IC chip 114 mounted to the second substrate 112. The TIM includes any material suitable for a given application to enhance heat transfer from one component to another. In some embodiments, the electronic assembly 110 and the integrated heat sink 120 are physically secured together using screws and thermally coupled using a TIM. As shown in FIG. Figure 1E and Figure 1F As shown, the electronic assembly 110 and the integrated heat sink 120 are disposed within a housing 130 (e.g., a plastic clamshell mold) and are covered by the housing, while the third cooling fin structure 125 and the guide rail contact structure 126 of the integrated heat sink 120 extend from the housing 130 and are exposed to the external environment and are not covered by the housing 130.

[0032] Figure 2A , Figure 2B and Figure 2C is a schematic perspective view of a solid state circuit breaker 100 coupled to a mounting rail 140 according to an exemplary embodiment of the present disclosure. Specifically, FIG. 2A to FIG. 2C An exemplary embodiment of a solid-state circuit breaker 100 coupled to a mounting rail 140 is shown, wherein the exposed rail contact structure 126 of the integrated heat sink 120 is in physical and thermal contact with the mounting rail 140. In an exemplary embodiment, the mounting rail 140 includes a DIN rail mount, and specifically, a top hat segment (TH) type DIN rail mount having a hat-shaped cross-section having a first lip 140-1 and a second lip 140-2. The DIN rail mount is a standard type of metal rail that is commonly used to mount circuit breakers and industrial control equipment within equipment racks. The DIN rail mount is typically made of cold rolled carbon steel sheet having a bright surface finish such as zinc plating or chrome plating. The mounting rail 140 is configured to provide mechanical support for the circuit breaker and does not conduct current.

[0033] Furthermore, if FIG. 2A to FIG. 2C As shown together, when the solid-state circuit breaker 100 is mounted to the mounting rail 140, the exposed rail contact structure 126 of the integrated heat sink 120 contacts the mounting rail 140 to provide a heat conduction path from the integrated heat sink 120 to the mounting rail 140, wherein the mounting rail 140 further acts as a heat sink to conduct heat from the solid-state circuit breaker 100. In some embodiments, the solid-state circuit breaker 100 is physically fixed to the mounting rail 140 by the operation of the third cooling fin structure 125 and the plastic mounting clip 134. Specifically, as shown in FIG. Figure 2C As specifically shown, the third cooling fin structure 125 essentially functions as a fixed mounting clip that engages the first lip 140-1 of the mounting rail 140, while the plastic mounting clip 134 (e.g., a slidable clip, a spring-loaded clip, etc.) engages the second lip 140-2 of the mounting rail 140, and the rail contact structure 126 functions as a support base structure (or DIN foot element) that slightly presses against the flat bottom portion of the mounting rail 140 between the first lip 140-1 and the second lip 140-2. In addition, the exposed third cooling fin structure 125 functions to dissipate heat from the integrated heat sink 120 to the surrounding air by convection.

[0034] As described above, the exemplary solid-state circuit breaker 100 having an integrated heat sink 120 and, in particular, an assembled configuration of an electronic assembly 110 and an integrated heat sink 120 provides a thermomechanical framework that is configured to absorb heat from and dissipate heat from the electronic components 113 and 114 of the electronic assembly 110 using a combination of heat transfer mechanisms including conduction and convection. Specifically, the thermomechanical framework provides a variety of conductive heat transfer modes (via conduction). For example, a first cooling plate 121 thermally coupled (via a TIM layer) to the back surface of the first substrate 111 provides a means for conductive heat transfer from the first substrate 111 to the integrated heat sink 120 to absorb heat generated by a high power or high voltage solid-state switching device 113 mounted on the front side of the first substrate 111. In this regard, the first substrate 111 essentially acts as a heat sink that absorbs heat from the solid-state switching device 113 and transfers the heat to the first cooling plate 121 of the integrated heat sink 120. Furthermore, the second cooling plate 122 thermally coupled (via the TIM layer) to the backside surface of the electronic IC chip 114 provides a means for conductive heat transfer from the electronic IC chip 114 to the second cooling plate 122 of the integrated heat sink 120 .

[0035] Another heat conduction mode is provided by conductive heat transfer from the first substrate 111 to the first and second wire terminal connectors 115 and 116 via respective connection tabs 115-1 and 116-1, and conductive heat transfer from the first and second wire terminal connectors 115 and 116 to the first and second wires 117 and 118 (e.g., 12-gauge wires). In this configuration, the first and second wires 117 and 118 essentially act as heat removal elements to dissipate heat to the external environment.

[0036] Further, heat conduction is provided by conductive heat transfer from the rail contact structure 126 of the integrated heat sink 120 to the mounting rail 140. Specifically, the heat absorbed by the first cooling plate 121 and the second cooling plate 122 and by the first cooling fin structure 123 and the second cooling fin structure 124 can be dissipated to the mounting rail 140 through the rail contact structure 126 of the integrated heat sink 120. The mounting rail 140 absorbs heat from the rail contact structure 126 and acts as a heat sink to dissipate the heat to the external environment (outside the solid state circuit breaker 100).

[0037] In addition, the thermomechanical frame provides a variety of convection heat transfer modes. For example, due to the relatively large temperature difference between the large amount of heat generated by the high-power solid-state switch device 113 and the small amount of heat generated by the electronic IC chip 114, a natural convection air flow occurs inside the housing 130 of the solid-state circuit breaker 100. In some cases, the amount of heat generated by the high-power solid-state switch device 113 can be about 8 to 10 times the amount of heat generated by the electronic IC chip 114. In this way, a convection air flow (heated air flow) is generated due to the temperature difference between the first cooling plate 121 and the second cooling plate 122. The convection air flow inside the housing 130 causes the heated air to flow to the first wire terminal connector 115 and the second wire terminal connector 116, and to the first cooling fin structure 123 and the second cooling fin structure 124, thereby causing convection heat transfer from the heated air to (i) the first wire terminal connector 115 and the second wire terminal connector 116, and to (ii) the first cooling fin structure 123 and the second cooling fin structure 124. In other words, the first wire terminal connector 115 and the second wire terminal connector 116 and the first cooling fin structure 123 and the second cooling fin structure 124 absorb heat from the heated air of the convective air flow, wherein the absorbed heat is dissipated to the external environment via conduction through the first wire 117 and the second wire 118 and the guide rail contact structure 126.

[0038] Another mode of convective heat transfer is provided by the externally exposed third cooling fin structure 125 of the integrated heat sink 120. Specifically, some of the heat absorbed by the integrated heat sink 120 is transferred to the third cooling fin structure 125, wherein convective heat transfer occurs, wherein heat from the third cooling fin structure 125 is dissipated to the ambient air outside the housing 130 of the solid state circuit breaker 100.

[0039] In some embodiments, the integrated heat sink 120 is molded to fit into a standard form factor of the circuit breaker housing 130. In addition, the clamping mechanism provided by the exposed third cooling fin structure 125 of the integrated heat sink 120 and the plastic mounting clip 134 (which is a component of the housing 130) is constructed to have a form factor compatible with a standard mounting rail such as a DIN rail mount. In addition, the solid-state circuit breaker 100 can be designed in the same or similar manner for different rated currents (e.g., 10 amperes (A), 20A, etc.). In this case, the number of solid-state switching devices 113 can vary depending on the rated current, as shown below in combination Figure 4 and Figure 5 discussed in further detail.

[0040] It should be noted that Figures 1A to 1F as well as FIG. 2A to FIG. 2C The exemplary embodiments of are merely illustrative embodiments of implementing a DIN rail mount circuit breaker that includes an integrated heat sink configured to absorb and dissipate heat from electronic components of the DIN rail mount circuit breaker, and wherein the integrated heat sink includes an extension portion that extends from a plastic housing of the DIN rail mount circuit breaker and is configured to be in thermal contact with the DIN rail mount to dissipate heat from the integrated heat sink to the DIN rail mount. However, the same or similar thermo-mechanical structures and techniques can be readily applied to thermal management of solid-state circuit breakers having other types of circuit breaker form factors, not just DIN circuit breaker form factors.

[0041] Additionally, while the exemplary embodiments are described in the context of a single-pole solid-state circuit breaker, it should be understood that the same or similar thermo-mechanical structures and techniques can be readily applied to the thermal management of a solid-state double-pole circuit breaker. Additionally, the same or similar thermo-mechanical structures and techniques can be readily applied to the thermal management of a hybrid circuit breaker that implements a combined solid-state switch and associated electronics and a mechanical switch (e.g., an air-gap switch). Additionally, while the exemplary embodiments are discussed herein in the context of an AC circuit breaker, it should be understood that the same or similar thermo-mechanical structures and techniques can be readily applied to the thermal management of a solid-state direct current (DC) circuit breaker.

[0042] It should also be understood that, for example Figure 1A The exemplary electronic assembly 110 shown is a generalized illustration of electronic components 113 and 114 disposed on a first substrate 111 and a second substrate 112, respectively, which is presented to describe exemplary thermo-mechanical structures and techniques for thermal management of solid-state circuit breakers. The type of electronic components 113 and 114 implemented and the associated AC switch and control circuit architecture will vary depending on, for example, the intelligent functions supported by the solid-state circuit breaker, the current rating of the solid-state circuit breaker, etc. For example, Figure 3The electronic components of the intelligent solid-state circuit breaker according to an exemplary embodiment of the present disclosure are schematically shown. Specifically, Figure 3 The intelligent solid-state circuit breaker 300 is schematically illustrated, and includes a first power input terminal 300-1, a second power input terminal 300-2, a first load terminal 300-3, a second load terminal 300-4, a solid-state AC switch 310, and an intelligent switch control system 320. The intelligent switch control system 320 includes various components and circuit systems, such as a controller 321, an AC switch driver circuit system 322, sensor circuit systems 323 and 324, one or more memory devices 325, a power converter 326, and a DC to DC conversion circuit system 327, the functions of which will be explained in detail below. In some embodiments, the solid-state AC switch 310 includes a bidirectional solid-state switch, which includes, for example, two solid-state switches connected in series back-to-back, and an exemplary embodiment of which will be described below in conjunction with Figure 4 The solid-state AC switch 310 is connected to the line-side node N1 and the load-side node N2 and is located between the line-side node and the load-side node. The intelligent switch control system 320 may include a system-on-chip (SoC) device or a system-in-package (SIP) device that integrates various components 321, 322, 323, 324, 325, 326, and 327 (or parts thereof) in a package structure.

[0043] The intelligent solid-state circuit breaker 300 is configured to control the AC power supplied from the AC power source 30 (e.g., AC mains) to the AC load 40. The first power input terminal 300-1 and the second power input terminal 300-2 are configured to connect the intelligent solid-state circuit breaker 300 to the line phase (L) 31 and the neutral phase (N) 32 of the AC power source 30. The first load terminal 300-3 and the second load terminal 300-4 are configured to connect the intelligent solid-state circuit breaker 300 to the load hot line 41 and the load neutral line 42 connected to the AC load 40, respectively. The neutral phase (N) 32 of the AC power source 30 is combined with the ground 33 (GND). The ground 33 is usually connected to the ground rod in the circuit breaker distribution board, where the ground rod is joined to the neutral bar in the circuit breaker distribution board. A ground connection is made from the ground rod in the circuit breaker distribution board to the ground terminal (not shown) of the intelligent solid-state circuit breaker 300. In the event of a ground fault condition detected by the intelligent solid-state circuit breaker 300 , the ground 33 provides an alternative low resistance path for the ground fault return current to flow.

[0044] The intelligent switch control system 320 implements control circuitry, control logic, and algorithms configured to intelligently control various functions and operations of the intelligent solid-state circuit breaker 300. The power converter 326 is configured to generate an output voltage V DCThe power converter 326 is coupled to the nodes N1 and N3, whereby the AC power input is applied to the power converter 326. In an exemplary embodiment, the power converter 326 generates an output voltage V DC The output voltage is referenced to the neutral point N (node ​​N3) of the AC power source 30. DC is applied to the input of the DC to DC conversion circuit system 327. The DC to DC conversion circuit system 327 is configured to convert the voltage V DC Converted to one or more regulated DC voltages, which are used as DC supply voltages to operate the components and circuitry of the intelligent switch control system 320.

[0045] In some embodiments, the DC-to-DC conversion circuit system 327 includes one or more DC-DC step-down switching regulator circuits (eg, step-down switching regulators) configured to convert the voltage V DC In some embodiments, the DC to DC conversion circuit system 327 is configured to convert the voltage V to a plurality of regulated DC rail voltages with different voltage levels according to the DC supply voltage requirements of the control circuit system of the intelligent switch control system 320 and the AC switch driver circuit system 322 as needed. DC Convert to, for example, one or more industry standard DC voltages, including but not limited to 12V, 10V, 5V, 3.3V, 2.5V, 2.7V, 1.8V, etc.

[0046] In some embodiments, the controller 321 is implemented using at least one intelligent programmable hardware processing device, such as a microprocessor, a microcontroller, an ASIC, an FPGA, a CPU, etc., which is configured to execute a software routine to generate a switch control signal (denoted as S_Con), which is applied to the AC switch driver circuit system 322 to intelligently control the operation of the solid-state AC switch 310 in response to the detection of a fault event (e.g., overcurrent, short circuit, ground fault, etc.), thereby performing various functions according to the configuration of the intelligent solid-state circuit breaker 300. In some embodiments, one or more memory devices 325 include volatile random access memory (RAM) and non-volatile memory (NVM), such as flash memory, which is used to store calibration data, operational data, and executable code for performing various intelligent operations of the intelligent solid-state circuit breaker 300.

[0047] exist Figure 3 In an exemplary embodiment of the present invention, the AC switch driver circuit system 322 is configured to generate a gate control signal (denoted as G_Con) in response to a switch control signal S_Con from the controller 321, wherein the gate control signal G_Con is applied to the control terminal of the solid-state AC switch 310 to turn on / off the solid-state AC switch 310. Figure 3 Not specifically shown, but in a neutral ground referenced design, some form of isolation circuitry and / or components will be implemented to provide AC-DC isolation and properly drive the solid-state AC switch 310 using the gate control signal G_Con generated by the AC switch driver circuitry 322.

[0048] In some embodiments, the sensor circuit system 323 includes a voltage detection and / or current detection circuit system to sense the line voltage and / or line current at the node N1 on the line side of the solid-state AC switch 310. Further, in some embodiments, the sensor circuit system 324 includes a voltage detection circuit system and / or a current detection circuit system to sense the load voltage and / or load current at the node N2 on the load side of the solid-state AC switch 310. The configuration and type of sensors used for the sensor circuit systems 323 and 324 will vary depending on the application. For example, the line-side sensor circuit system 323 may include a voltage phase detector to determine the zero crossing of the AC supply voltage waveform at the node N1 and the polarity transition direction of the AC supply voltage waveform at the node N1 (e.g., the AC supply voltage waveform V S The zero crossing detection is processed by the controller 321 to determine and control the timing of the solid state AC switch 310 being activated and deactivated after detecting the zero crossing voltage of the AC supply voltage waveform at the line sense node N1.

[0049] In some embodiments, for smart circuit breaker applications, the load-side sensor circuit system 324 includes a current detection circuit system to sense the magnitude of the load current at the node N2. In this regard, the controller 321 can utilize the sensor circuit system 324 to detect a fault condition, such as an overcurrent, a short circuit, etc., and allow the controller 321 to generate a switch control signal S_Con to deactivate the solid-state AC switch 310 if a fault condition is detected. In some embodiments, the smart solid-state circuit breaker 300 is implemented using the exemplary circuit breaker architecture and technology disclosed in U.S. Patent No. 11,373,831, which is commonly assigned and fully incorporated herein by reference.

[0050] like Figure 3 As schematically shown in FIG. 1 , the solid-state AC switch 310 is connected between the line-side node N1 and the load-side node N2 in the electrical path between the first power input terminal 300-1 and the first load terminal 300-3. As described above, in some embodiments, the solid-state AC switch 310 includes a bidirectional solid-state switch device including two serially connected solid-state switches having a common node connection. For example, Figure 4 Schematically illustrates an exemplary embodiment of the present disclosure Figure 3An embodiment of a solid-state AC switch that can be implemented in a smart solid-state circuit breaker 300.

[0051] More specifically, Figure 4 A bidirectional solid-state switch 400 is schematically shown, and the bidirectional solid-state switch includes a first solid-state switch 401 and a second solid-state switch 402, which are serially connected between a first node N1 and a second node N2 and are coupled back-to-back at a node N4. In some embodiments, Figure 1A and Figure 2B The two solid-state switch devices 113 shown include a first solid-state switch 401 and a second solid-state switch 402. In some embodiments, the bidirectional solid-state switch 400 includes a bidirectional MOSFET switch, wherein the first solid-state switch 401 and the second solid-state switch 402 include power MOSFET devices, such as N-type enhancement MOSFET devices, having corresponding gate terminals (G), drain terminals (D) and source terminals (S). The drain terminal (D) of the first solid-state switch 401 is coupled to the line side node N1, and the drain terminal (D) of the second solid-state switch 402 is coupled to the load side node N2. The source terminals (S) of the first solid-state switch 401 and the second solid-state switch 402 are usually coupled at a common node N4, thereby implementing a common source bidirectional MOSFET switch configuration. The gate terminals (G) of the first solid-state switch 401 and the second solid-state switch 402 are usually connected to the node N5 through corresponding resistors 410 and 411.

[0052] like Figure 4 As further shown, the first solid-state switch 401 and the second solid-state switch 402 include intrinsic body diodes 401-1 and 402-1, respectively, wherein each intrinsic body diode 401-1 and 402-1 represents a PN junction between a P-type substrate body and an N-doped drain region of a corresponding N-type MOSFET device. It should be noted that the intrinsic body-to-source diodes of the first solid-state switch 401 and the second solid-state switch 402 are not shown because such intrinsic body-to-source diodes are assumed to be shorted by a common connection between the source terminal (S) and the body terminal (e.g., the N+ source region and the P-doped body junction are shorted by the source metallization).

[0053] Although Figure 4 An exemplary embodiment is shown in which the bidirectional solid-state switch 400 includes two MOSFET devices (e.g., a first solid-state switch 401 and a second solid-state switch 402), but in some embodiments, such as in combination with Figure 5As further explained in detail, each of the first solid-state switch 401 and the second solid-state switch 402 can be implemented with two or more MOSFET devices connected in parallel, the configuration of the two or more MOSFET devices achieving enhanced heat dissipation and enhanced power handling. In addition, in some embodiments, the bidirectional solid-state switch 400 can be implemented using other types of solid-state switch devices. For example, in some embodiments, the first solid-state switch 401 and the second solid-state switch 402 are implemented using integrated gate bipolar transistor (IGBT) devices, the emitter terminals of which are typically connected at a common node N4. In other embodiments, the first solid-state switch 401 and the second solid-state switch 402 can be implemented using other types of FET devices, including but not limited to GaN (gallium nitride) FET devices, cascaded GaN FET devices, silicon carbide (SiC) junction FET devices, cascaded SiC junction FET devices, etc.

[0054] In all embodiments, the bidirectional solid-state switch 400 is configured to: (i) allow AC current to flow bidirectionally in the electrical path between nodes N1 and N2 when the bidirectional solid-state switch 400 is in the on state, and (ii) interrupt the bidirectional flow of AC current in the electrical path between nodes N1 and N2 when the bidirectional solid-state switch 400 is in the off state. As described above, the bidirectional solid-state switch 400 can be turned on and off by applying appropriate gate control signals G_Con to the gate (G) terminals of the first solid-state switch 401 and the second solid-state switch 402, which are generally coupled to the node N5.

[0055] Figure 5 Schematically illustrates an embodiment of a solid-state AC switch that can be implemented in a solid-state circuit breaker according to an exemplary embodiment of the present disclosure. Specifically, Figure 5 A solid-state AC switch 500 is schematically illustrated, comprising a plurality of bidirectional solid-state switches 510, 520, and 530 connected in parallel between a node N1 and a node N2. For ease of illustration, Figure 5 The gate control line is not shown. The bidirectional solid-state switch 510 includes a first solid-state switch 511 and a second solid-state switch 512 connected in series back-to-back between the node N1 and the node N2. The bidirectional solid-state switch 520 includes a first solid-state switch 521 and a second solid-state switch 522 connected in series back-to-back between the node N1 and the node N2. The bidirectional solid-state switch 530 includes a first solid-state switch 531 and a second solid-state switch 532 connected in series back-to-back between the node N1 and the node N2. The exemplary configuration of the solid-state AC switch 500 achieves enhanced heat dissipation and enhanced power handling for, for example, a circuit breaker with a high current rating (e.g., 20A or greater). It should be noted that Figure 5 It shows how Figure 1A and Figure 2BThe illustrated first substrate 111 will include an exemplary configuration of six (6) solid state switches disposed on a front side of the first substrate 111 with a first cooling plate 121 coupled to a back side of the first substrate 111 to absorb heat generated by the six (6) solid state switches.

[0056] The description of the various embodiments of the present disclosure is presented for illustrative purposes and is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or technical improvements to technologies found in the marketplace, or to enable those of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A circuit breaker comprising an integrated heat sink configured to absorb and dissipate heat from electronic components of the circuit breaker using a combination of conduction and convection.

2. The circuit breaker according to claim 1, wherein: The integrated heat sink is disposed within a plastic housing of the circuit breaker; and The integrated heat sink includes at least one extension portion extending from the plastic housing and configured to dissipate heat to an external environment. 3 . The circuit breaker of claim 2 , wherein the at least one extension portion includes an external cooling fin structure configured to dissipate heat to external ambient air by convective heat transfer.

4. The circuit breaker of claim 2, wherein the at least one extension portion comprises a rail contact structure configured to couple to a circuit breaker mounting rail and dissipate heat to the circuit breaker mounting rail by conductive heat transfer.

5. The circuit breaker of claim 4, wherein the circuit breaker mounting rail comprises a DIN rail mount.

6. The circuit breaker of claim 1, wherein the integrated heat sink comprises a unitary molded element formed of a thermally conductive material.

7. The circuit breaker of claim 6, wherein the integrated heat sink comprises a unitary molded aluminum structure.

8. The circuit breaker according to claim 1, wherein: The circuit breaker includes an electronic assembly, the electronic assembly including a first substrate and a second substrate; The electronic assembly includes: (i) a plurality of solid-state switching devices mounted on the first substrate and configured to implement a solid-state alternating current (AC) switch; and (ii) an integrated circuit (IC) chip mounted on the second substrate and configured to implement control circuitry for controlling operation of the solid-state AC switch; The integrated heat sink comprises a first cooling plate and a second cooling plate; The first substrate and the second substrate of the electronic assembly are disposed between the first cooling plate and the second cooling plate; and The first cooling plate and the second cooling plate are configured to absorb heat generated by the electronic components through conduction.

9. The circuit breaker according to claim 8, wherein: the plurality of solid-state switching devices being mounted on a front surface of the first substrate; The IC chip is mounted on the front surface of the second substrate; The first cooling plate is thermally coupled to a back surface of the first substrate, the back surface being opposite to the front surface of the first substrate; and The second cooling plate is thermally coupled to a back surface of the IC chip.

10. The circuit breaker according to claim 8, wherein: The electronic assembly includes a first wire connector terminal coupled to the first substrate and a second wire connector terminal coupled to the first substrate; The first and second wire connector terminals are configured to absorb heat from the first substrate by conduction and dissipate the heat to an external environment by conduction of the heat to electrical wiring connected to the first and second wire connector terminals.

11. The circuit breaker according to claim 8, wherein the first cooling plate and the second cooling plate are configured to absorb heat generated by the electronic components and generate a temperature difference between the first cooling plate and the second cooling plate, the temperature difference causing a convective air flow within the housing of the circuit breaker to circulate heated air to other components of the integrated heat sink and causing convective heat transfer from the heated air to the other components of the integrated heat sink.

12. The circuit breaker of claim 11, wherein the other components of the integrated heat sink include one or more cooling fin structures.

13. A circuit breaker comprising: An electronic assembly, the electronic assembly comprising an electronic component; as well as an integrated heat sink configured to absorb and dissipate heat from the electronic components of the electronic assembly; wherein the integrated heat sink comprises a first cooling plate and a second cooling plate; At least a portion of the electronic assembly is disposed between the first cooling plate and the second cooling plate, so that the first cooling plate and the second cooling plate absorb heat generated by the electronic assembly through conduction.

14. The circuit breaker according to claim 13, wherein the first cooling plate and the second cooling plate are configured to absorb heat generated by the electronic components and generate a temperature difference between the first cooling plate and the second cooling plate, the temperature difference causing a convective air flow within the housing of the circuit breaker to circulate heated air to other components of the integrated heat sink and causing convective heat transfer from the heated air to the other components of the integrated heat sink.

15. The circuit breaker of claim 13, wherein the other components of the integrated heat sink include one or more cooling fin structures.

16. The circuit breaker of claim 13, wherein: The electronic assembly includes a first wire connector terminal and a second wire connector terminal; The first and second electric wire connector terminals are configured to absorb heat by conduction and dissipate the heat to an external environment by conduction of the heat to electrical wiring connected to the first and second electric wire connector terminals.

17. The circuit breaker of claim 13, wherein: The integrated heat sink includes at least one extension portion extending from a plastic housing of the circuit breaker and configured to dissipate heat to an external environment.

18. The circuit breaker of claim 17, wherein the at least one extended portion of the integrated heat sink comprises: a rail contact structure configured to couple to a circuit breaker mounting rail and dissipate heat to the circuit breaker mounting rail by conductive heat transfer; as well as an external cooling fin structure configured to dissipate heat to external ambient air by convective heat transfer; The external cooling fin structure is further configured as a fixing clip mechanism to combine with the plastic clip of the plastic housing to fix the circuit breaker to the mounting rail.

19. A DIN rail mount circuit breaker comprising an integrated heat sink configured to absorb and dissipate heat from electronic components of the DIN rail mount circuit breaker, wherein the integrated heat sink comprises a first extension portion extending from a plastic housing of the DIN rail mount circuit breaker and configured to be in thermal contact with a DIN rail mount to dissipate heat from the integrated heat sink to the DIN rail mount.

20. The DIN rail mount circuit breaker of claim 19, wherein the integrated heat sink further comprises a second extension portion, the second extension portion: (i) configured to dissipate heat to external ambient air by convective heat transfer, and (ii) configured to operate as a retaining clip mechanism to combine with a plastic clip of the plastic housing to secure the DIN rail mount circuit breaker to the DIN rail mount.

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