Electric device and electric aircraft

Abstract

To provide an electric apparatus having fire resistance and capable of preventing fire from spreading to other apparatuses.SOLUTION: The electrical apparatus 10 according to the present invention comprises an electrical component 40 and a cable 11 electrically connected to the electrical component 40. The cable 11 includes a core 13, a first coating portion 15 provided on a surface of the core 13, and a second coating portion 12 provided on a surface of the first coating portion 15. The first coating portion 15 is made of an inorganic incombustible material. The second coating part 12 is a fireproof structure composed of a fibrous inorganic fireproof material. The first coating part 15 and the second coating part 12 are impregnated with a permeable refractory material 17.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric device, particularly an electric device connected to a cable, and an electric aircraft equipped with the electric device. [Background technology]

[0002] In order to realize a zero-carbon society, countries around the world are strongly calling for CO2 emission restrictions, and the electrification of power systems is being actively promoted as an alternative to fossil fuel-powered engines. The replacement of all engine-driven mobility products with motor drive systems is being considered, and at the same time, technological solutions are being sought, such as improving the output density of electrical equipment, such as power electronics. For example, in the case of aircraft, preventing problems before they occur is both important and necessary to ensure safety in the air, and further technological solutions are being sought, such as improved environmental resistance, improved cooling performance, higher voltage, and lighter weight.

[0003] Examples of conventional electrical devices are described in Patent Documents 1 and 2.

[0004] Patent Document 1 describes a high-voltage wire harness connected to an inverter unit. This wire harness includes a conductive path, a non-metallic fiber braid, and a conductive resin molded product. The non-metallic fiber braid is formed into a tubular shape using ultra-fine wires made of conductive non-metallic fibers and covers the conductive path. The non-metallic fiber is a conductive resin fiber made by mixing a conductive material with carbon fiber or a resin material. This configuration can reduce noise superimposed on the conductive path.

[0005] Patent Document 2 describes an electric compressor for an automotive air conditioner that is equipped with an inverter device. In this electric compressor, a cable is connected to the inverter device, and all or at least a portion of the cable on the electric compressor side is provided with a self-extinguishing or fire-resistant coating. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-073987 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-127606 Summary of the Invention [Problem to be solved by the invention]

[0007] It is extremely important for electrical equipment, especially in the aircraft field, not to catch fire. Electrical equipment in the aircraft field is required to maintain its functionality for a certain period of time even if it catches fire due to an external factor (for example, a fire spreading from another device or a lightning strike). In particular, the cables connecting to other devices are physically connected, so it is necessary to prevent the fire from spreading to other devices and from other devices. In other words, electrical equipment, especially in the aircraft field, is required to be non-flammable so that it does not spread fire to surrounding devices via cables, and to be lightweight yet fire-resistant.

[0008] An object of the present invention is to provide an electric device that is fire-resistant and can prevent the spread of fire to other devices, and an electric aircraft equipped with this electric device. [Means for solving the problem]

[0009] The electrical device according to the present invention comprises an electrical component and a cable electrically connected to the electrical component. The cable comprises a core material, a first covering portion provided on the surface of the core material, and a second covering portion provided on the surface of the first covering portion. The first covering portion is made of a non-combustible inorganic material. The second covering portion is a fire-resistant structure made of a fibrous inorganic fire-resistant material. The first covering portion and the second covering portion are impregnated with a penetrating fire-resistant material.

[0010] The electric aircraft according to the present invention comprises the electric equipment according to the present invention. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an electric device that is fire-resistant and can prevent the spread of fire to other devices, and an electric aircraft equipped with this electric device. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram schematically illustrating a configuration of an electrical device according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a diagram schematically illustrating the configuration of an electrical device according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a diagram schematically illustrating the configuration of an electrical device according to a third embodiment of the present invention. [Figure 4] FIG. 10 is a diagram schematically illustrating the configuration of an electrical device according to a fourth embodiment of the present invention. [Figure 5] FIG. 10 is a diagram schematically illustrating the configuration of an electrical device according to a fifth embodiment of the present invention. [Figure 6] FIG. 10 is a diagram schematically illustrating the configuration of an electrical device according to a sixth embodiment of the present invention. [Figure 7] FIG. 10 is a diagram schematically illustrating an example of an electric aircraft according to a seventh embodiment of the present invention. [Figure 8] FIG. 10 is a diagram schematically illustrating another example of an electric aircraft according to a seventh embodiment of the present invention. [Figure 9] FIG. 12 is a diagram schematically illustrating yet another example of an electric aircraft according to a seventh embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The electrical equipment according to the present invention can be used in, for example, aircraft, transportation equipment, and construction machinery. The electrical equipment according to the present invention includes electrical components and cables electrically connected to the electrical components, and even if the electrical equipment is exposed to fire, the insulation of the cables can be ensured, allowing the system including the electrical equipment to function. Furthermore, even if the electrical equipment according to the present invention is physically connected to other equipment by cables, the electrical equipment can prevent the spread of fire from or to other equipment.

[0014] When the electrical equipment according to the present invention is used in an aircraft, for example, even if it is exposed to a flame, it can maintain its functionality as an electrical equipment for the period of time specified by fire resistance standards.

[0015] Hereinafter, an electric device and an electric aircraft according to an embodiment of the present invention will be described with reference to the drawings. In the drawings referred to in this specification, the same or corresponding components are designated by the same reference numerals, and repeated description of these components may be omitted.

[0016] In the following embodiments, an example will be described in which the electrical device is a power converter (e.g., an inverter). The rated voltage of the power converter is 200V or more (particularly, 400V or more). The present invention can be applied not only to power converters but also to other electrical devices such as rotating machines, batteries, transformers, and circuit breakers. [Example]

[0017] An electric device according to a first embodiment of the present invention will be described.

[0018] FIG. 1 is a diagram schematically illustrating the configuration of an electric device 10 according to a first embodiment of the present invention.

[0019] The electrical device 10 according to this embodiment is a power conversion device and includes a housing 90, electrical components housed in the housing 90, and a cable 11. The electrical components include, for example, a capacitor 30, a switching device 40, and a substrate 50. The switching device 40 is, for example, an IGBT (insulated gate bipolar transistor).

[0020] The case 90 includes a housing 92 which is a lower metal case, and a cover 91 which is placed on top of the housing 92 .

[0021] The switching device 40 and the capacitor 30 are placed on a housing 92 inside a case 90, with a substrate 50 placed on top.

[0022] The cable 11 is electrically connected to the electrical components housed in the housing 90. The cable 11 connects the electrical components of the electrical device 10 to other devices, and is used to supply power to the electrical components and to transmit and receive signals between the electrical device 10 and other devices.

[0023] The cable 11 includes a core material 13 in the center in the radial direction, a first covering portion 15 on the surface of the core material 13, and a second covering portion 12 on the surface of the first covering portion 15.

[0024] The first covering portion 15 is made of a non-combustible material (or fire-resistant material) made of an inorganic material. The first covering portion 15 is lightweight because it is made of a wool-like or cotton-like material, i.e., woven fibers. For example, the first covering portion 15 is made of a non-metallic wool-like material such as glass wool, rock wool, ceramic wool, or glass mat. The first covering portion 15 is impregnated with a penetrating fire-resistant material, which is a fire-resistant material with permeability (fluidity), between the fibers.

[0025] The first covering portion 15 does not have to be wool-like or cotton-like, and can be made of a fire-resistant material such as steatite or cement. In this case, holes are formed in the base material, and the holes are impregnated with a penetrating fire-resistant material, so that the first covering portion 15 is impregnated with the penetrating fire-resistant material.

[0026] The second covering portion 12 is a fire-resistant structure made of an inorganic fire-resistant material. This fire-resistant material is, for example, fibrous inorganic fiber. The second covering portion 12 is made of, for example, a material in which silica yarn or alumina yarn is tightly woven. The second covering portion 12 has a mesh formed by the woven fibers impregnated with the above-mentioned penetrating fire-resistant material.

[0027] The penetrating fireproofing material acts as a fire-resistant adhesive and can be impregnated into the first coating portion 15 and the second coating portion 12, for example, by coating or filling the first coating portion 15 and the second coating portion 12 with the material.

[0028] The permeable fireproof material may be, for example, an existing fireproof putty 17. The fireproof putty 17 is made of an inorganic material and has adhesive properties. The fireproof putty 17 is based on a fireproof inorganic material and an inorganic polymer, and its main components are, for example, zirconium silicate, alumina (powder), ceramic, and steatite. The fireproof putty 17 may also contain cement, fireclay, etc.

[0029] In the electric device 10 according to this embodiment, the cable 11 includes a first covering 15 made of a non-combustible material (or a fire-resistant material) on the outside of the core material 13, and a second covering 12 made of a fire-resistant material on the outside of the first covering 15. This configuration makes the cable 11 fire-resistant and non-combustible, and it will not catch fire or burn. Even if the first covering 15 were to burn, the second covering 12 can prevent the core material 13 of the cable 11 from being exposed. Furthermore, if the first covering 15 is wool-like or cotton-like and the second covering 12 is fibrous, the thickness of the portion covering the core material 13 can be increased.

[0030] In cable 11, if the thickness of first coating 15 and second coating 12, which are the portions that coat core 13, is 0.5 mm or more, even if metal comes into contact with the surface of cable 11 for some reason, partial discharge can be prevented as long as the potential difference between this metal and core 13 is 400 V or less. The thicker first coating 15 and second coating 12 are, the greater the effect of preventing partial discharge.

[0031] In the electrical device 10 of this embodiment, by increasing the thickness of the first covering portion 15 and the second covering portion 12 that cover the core material 13, even if a fire breaks out due to an external factor and the cable 11 is exposed to the fire, or even if a metal structure around the electrical device 10 or the cable 11 comes into contact with the surface of the cable 11, the core material 13 can be prevented from being exposed and damaged, and discharge or short circuit of the core material 13 can be prevented.

[0032] The cable 11 preferably includes a moisture-proof material 19 on the surface of the second coating 12, i.e., on the surface of the cable 11. The moisture-proof material 19 prevents the second coating 12 from deteriorating due to moisture. For example, the moisture-proof material 19 prevents the second coating 12 made of yarn from absorbing moisture and deteriorating.

[0033] Moisture-proof material 19 is made of, for example, a thin metal film, a metal vapor deposition film, an epoxy resin, or a metal braided wire. When electrical device 10 is used in the aircraft field, for example, it is preferable that the thin metal film or metal braided wire be thin in order to make cable 11 lightweight. Note that insulation between the thin metal film or metal braided wire and core material 13 is ensured by the thickness of first coating 15 and second coating 12, so no discharge or short circuit occurs between them.

[0034] In the electric device 10 according to this embodiment, the cable 11 has the configuration described above, and is fire-resistant in the unlikely event of a fire, preventing the fire from spreading to other devices. The electric device 10 can ensure moisture resistance of the cable 11 while also ensuring electrical insulation, thereby ensuring sufficient long-term structural reliability. Therefore, the electric device 10 according to this embodiment has high structural reliability and can satisfy the multiple requirements, for example, in the aircraft field. [Example]

[0035] Second Embodiment An electric device 10 according to a second embodiment of the present invention will be described below. Differences between the electric device 10 according to the second embodiment and the electric device 10 according to the first embodiment will be mainly described below.

[0036] FIG. 2 is a diagram schematically illustrating the configuration of an electric device 10 according to a second embodiment of the present invention.

[0037] The electrical device 10 according to this embodiment differs from the electrical device 10 according to Example 1 (FIG. 1) in the permeable fire-resistant material impregnated in the first covering portion 15 and the second covering portion 12. In the electrical device 10 according to this embodiment, the permeable fire-resistant material is made of a permeable organic material, namely, a permeable organic substance 14. The permeable organic substance 14 is preferably made of a material having excellent flexibility, such as silicone, silicone rubber, rubber, urethane, mortar, synthetic rubber, clay, polymer gel, or elastomer.

[0038] In the electrical device 10 according to this embodiment, the permeable fire-resistant material is composed of the permeable organic matter 14, so the strength of the cable 11 can be maintained against a large external force. For example, even if the cable 11 is subjected to mechanical force or deterioration due to moisture absorption, the force can be absorbed and the progress of moisture-absorption deterioration can be suppressed, so that the structure of the cable 11 can be maintained. [Example]

[0039] An electric device 10 according to a third embodiment of the present invention will be described below. Differences between the electric device 10 according to the third embodiment and the electric device 10 according to the first embodiment will be mainly described below.

[0040] FIG. 3 is a diagram schematically illustrating the configuration of an electric device 10 according to a third embodiment of the present invention.

[0041] In the electric device 10 according to this embodiment, the cable 11 does not include a moisture-proof material 19 on the surface of the second covering portion 12. Since the electric device 10 according to this embodiment does not include a moisture-proof material 19, the cable 11 can be made lighter and costs can also be reduced.

[0042] The electrical device 10 according to this embodiment is preferably installed in an environment where there is little moisture absorption and deterioration of the second covering portion 12. Alternatively, it is preferably installed in an environment where maintenance and part replacement can be performed periodically to improve structural reliability. [Example]

[0043] An electric device 10 according to a fourth embodiment of the present invention will be described below. Differences between the electric device 10 according to the fourth embodiment and the electric device 10 according to the first embodiment will be mainly described below.

[0044] FIG. 4 is a diagram schematically illustrating the configuration of an electric device 10 according to a fourth embodiment of the present invention.

[0045] The electric device 10 according to this embodiment includes an ignition detection unit 45 inside the housing 90. The ignition detection unit 45 is an ignition sensor that detects ignition in the unlikely event that a ignition occurs inside the housing 90. The ignition detection unit 45 detects ignition by detecting, for example, heat, smoke, or flammable gas, preferably by detecting heat.

[0046] The electric device 10 according to this embodiment stops operating when the ignition detection unit 45 detects a fire. For example, if the electric device 10 is a power conversion device in an aircraft and forms a redundant system (i.e., there are multiple electric devices 10), the electric device 10 in which a fire is detected stops operating the moment the ignition detection unit 45 detects a slight fire.

[0047] The electric device 10 according to this embodiment includes the fire detection unit 45, which makes it possible to ensure the safety of the electric device 10 in the event of a fire, and also to prevent the fire from spreading to other devices. [Example]

[0048] An electric device 10 according to a fifth embodiment of the present invention will be described below. Differences between the electric device 10 according to the fifth embodiment and the electric device 10 according to the first embodiment will be mainly described below.

[0049] FIG. 5 is a diagram schematically illustrating the configuration of an electric device 10 according to a fifth embodiment of the present invention.

[0050] The electric device 10 according to this embodiment includes an ignition detection unit 45 inside the housing 90. The ignition detection unit 45 has the same configuration as the ignition detection unit 45 described in the fourth embodiment (FIG. 4).

[0051] Furthermore, in the electric device 10 according to this embodiment, the cable 11 is provided with a cable cutting unit 41. The cable cutting unit 41 has a mechanism for physically cutting the cable 11 in the unlikely event that the electric device 10 or the cable 11 is exposed to fire or catches fire. By physically cutting the cable 11, the cable cutting unit 41 separates the cable 11 from other devices and prevents the fire from spreading to the other devices.

[0052] The cable cutting unit 41 includes a control device (not shown). When the ignition detection unit 45 detects a fire inside the housing 90, the control device activates the cable cutting unit 41 to physically cut off the cable 11. Alternatively, when an ignition sensor installed near the electrical device 10 or the cable 11 detects that the electrical device 10 or the cable 11 has been exposed to fire or has caught fire, the control device activates the cable cutting unit 41 to physically cut off the cable 11.

[0053] The control device also monitors the current flowing through the cable 11, and if the current flowing through the cable 11 changes and exceeds the normal range, it may determine that the electrical equipment 10 or the cable 11 has been exposed to fire or has caught fire, and may activate the cable cutting unit 41 to physically cut off the cable 11.

[0054] The cable cutting unit 41 has a blade, and when activated, cuts the cable 11 with the blade, thereby physically disconnecting the cable 11. Alternatively, if the cable 11 has a configuration in which two cables are connected to each other, the cable cutting unit 41 has a mechanism for disconnecting the two cables from each other, and when activated, the mechanism separates the two cables from each other, thereby physically disconnecting the cable 11.

[0055] The cable cutting unit 41 may include a switch that stops the current from flowing through the cable 11. In this case, the cable cutting unit 41 stops the current from flowing through the cable 11 using the switch, and then physically disconnects the cable 11.

[0056] The electrical device 10 of this embodiment is provided with a cable cutting section 41 that physically cuts off the cable 11, so that in the unlikely event that the electrical device 10 or the cable 11 is exposed to fire or catches fire, the cable 11 can be physically cut off, thereby preventing the fire from spreading to other devices. [Example]

[0057] An electric device 10 according to a sixth embodiment of the present invention will be described below. Differences between the electric device 10 according to the sixth embodiment and the electric device 10 according to the first embodiment will be mainly described below.

[0058] FIG. 6 is a diagram schematically illustrating the configuration of an electric device 10 according to a sixth embodiment of the present invention.

[0059] The electric device 10 according to this embodiment includes an ignition detection unit 45 inside the housing 90. The ignition detection unit 45 has the same configuration as the ignition detection unit 45 described in the fourth embodiment (FIG. 4).

[0060] Furthermore, in the electric device 10 according to this embodiment, the housing 92 of the casing 90 includes a flow path 93 through which a liquid 94 flows. The liquid 94 is a liquid refrigerant such as cooling water, and is supplied to the flow path 93 from outside the electric device 10 to cool the electric components (e.g., the switching device 40) housed in the casing 90. The flow path 93 includes a control device (not shown) and an electronic valve 95, and when the control device opens the electronic valve 95, the liquid 94 flowing through the flow path 93 is supplied to the inside of the casing 90.

[0061] The control device opens the electronic valve 95 when the ignition detection unit 45 detects a fire inside the housing 90. When the electronic valve 95 opens in response to a command from the control device, it supplies the liquid 94 flowing through the flow path 93 into the inside of the housing 90. In the unlikely event that a fire occurs inside the housing 90, the electric device 10 according to this embodiment supplies the liquid 94 into the inside of the housing 90 to extinguish the fire inside the housing 90.

[0062] It should be noted that this embodiment is premised on the premise that the electric devices 10 constitute a redundant system (i.e., there are a plurality of electric devices 10). An electric device 10 that catches fire and supplies liquid 94 to the inside of the housing 90 may stop functioning and become unusable, but by using another electric device 10 instead, the function of the entire system can be maintained.

[0063] The electrical device 10 of this embodiment can extinguish a fire inside the housing 90 by supplying the liquid 94 flowing through the flow path 93 to the inside of the housing 90, and can also prevent the fire from spreading to other devices. [Example]

[0064] An electric aircraft 100 according to a seventh embodiment of the present invention will now be described.

[0065] 7 is a diagram schematically illustrating an example of an electric aircraft 100 according to a seventh embodiment of the present invention. In FIG. 7, an electric aircraft 100 for a large passenger aircraft is shown as an example.

[0066] The electric aircraft 100 includes a wing 104 and a drive system 103 that drives the electric aircraft 100. The drive system 103 includes a motor 102 and an inverter 101. The inverter 101 is the electric equipment 10 according to the present invention. Note that the electric aircraft 100 can include the electric equipment 10 according to the present invention in addition to the drive system 103.

[0067] Due to factors such as thrust, the electric aircraft 100 is basically provided with a drive system 103 in the same location as a fuel-burning jet engine. However, the electric aircraft 100 may have more drive systems 103 than a jet engine. This is because the drive system 103, which includes the motor 102 and inverter 101, is smaller and lighter than a conventional jet engine, allowing for greater freedom in its placement on the aircraft. Furthermore, to ensure safety through redundancy, it is generally considered that the drive systems 103 are distributed and placed in multiple locations. Therefore, the drive systems 103 may be placed in any number of locations on the aircraft.

[0068] If the electric aircraft 100 has a hybrid configuration including the drive system 103 and a jet engine, the drive system 103 may be located near the jet engine generator. In this case, the motor 102 and inverter 101 included in the drive system 103 may be required to have high heat resistance in addition to being able to withstand environmental exposure due to the proximity of the jet engine. The inverter 101 is an electric device 10 according to an embodiment of the present invention, and therefore has fire resistance and high heat resistance.

[0069] Figure 8 is a diagram schematically illustrating another example of an electric aircraft 100 according to a seventh embodiment of the present invention. Figure 8 shows, as an example, an electric aircraft 100 intended for a personal transport aircraft (for example, a so-called "flying car"). The electric aircraft 100 shown in Figure 8 has a smaller body than the electric aircraft 100 intended for a large passenger aircraft such as that shown in Figure 7.

[0070] In the electric aircraft 100 shown in Fig. 8, the drive system 103 is arranged at any position, similar to the electric aircraft 100 shown in Fig. 7. However, the drive system 103 in the electric aircraft 100 shown in Fig. 8 is smaller in size than the drive system 103 in the electric aircraft 100 designed for large passenger aircraft such as that shown in Fig. 7.

[0071] Figure 9 is a diagram schematically illustrating yet another example of an electric aircraft 100 according to a seventh embodiment of the present invention. Figure 9 illustrates, as an example, an electric aircraft 100 for a personal transport aircraft (such as a so-called "flying car") that is capable of vertical takeoff and landing.

[0072] In electric aircraft 100 shown in Fig. 9, drive system 103 is arranged at an arbitrary position, similar to electric aircraft 100 shown in Fig. 8. However, electric aircraft 100 shown in Fig. 9 also includes drive system 103 for vertical takeoff and landing.

[0073] The electric aircraft 100 according to this embodiment (FIGS. 7 to 9) includes the electric equipment 10 according to the embodiment of the present invention, that is, the electric equipment 10 that is fire-resistant and can prevent the spread of fire to other equipment. Therefore, the electric aircraft 100 according to this embodiment can satisfy the structural reliability requirements in the aircraft field.

[0074] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to embodiments including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete part of the configuration of each embodiment, or to add or replace other configurations. [Explanation of symbols]

[0075] 10...electrical equipment, 11...cable, 12...second coating part, 13...core material, 14...penetrating organic substance, 15...first coating part, 17...fireproof putty, 19...moisture-proof material, 30...capacitor, 40...switching device, 41...cable cutting part, 45...ignition detection part, 50...circuit board, 90...casing, 91...cover, 92...housing, 93...flow path, 94...liquid, 95...electronic valve, 100...electric aircraft, 101...inverter, 102...motor, 103...drive system, 104...wing

Claims

1. Electrical components and a cable electrically connected to the electrical component; Equipped with the cable includes a core material, a first covering portion provided on a surface of the core material, and a second covering portion provided on a surface of the first covering portion, the first covering portion is made of a non-combustible inorganic material, the second covering portion is a fire-resistant structure made of a fibrous inorganic fire-resistant material, The first covering portion and the second covering portion are impregnated with a penetrating fireproof material. An electrical device characterized by:

2. The penetrating fireproof material is a fireproof putty. The electrical device according to claim 1 .

3. The permeable fireproof material is composed of a permeable organic material. The electrical device according to claim 1 .

4. The cable includes a moisture-proof material on a surface of the second covering portion. The electrical device according to claim 1 .

5. a housing that houses the electrical components; an ignition detection unit that is installed inside the housing and detects an ignition inside the housing; Equipped with The electrical device according to claim 1 .

6. a cable cutting unit that physically cuts off the cable; the cable cutting unit cuts off the cable when the ignition detection unit detects a ignition inside the housing. The electrical device according to claim 5.

7. the housing includes a flow path through which a liquid flows and an electronic valve provided in the flow path; the electronic valve supplies the liquid into the housing when the ignition detection unit detects a ignition inside the housing; The electrical device according to claim 5.

8. The electrical device according to claim 1, An electric aircraft characterized by:

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