Surge recovery structures, electrical equipment for aircraft and electrical equipment for wind power generation

The surge recovery structure addresses impedance challenges in non-metallic housings by using resistors and capacitances to form a low-impedance path, achieving cost-effective and compact surge protection.

JP7770245B2Active Publication Date: 2025-11-14MITSUBISHI ELECTRIC CORP
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Patent Information

Application Number
JP2022078190
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2022-05-11
Publication Date
2025-11-14
Estimated Expiration
2042-05-11

AI Technical Summary

Technical Problem

Conventional surge recovery structures using non-metallic materials face challenges in forming a path with lower impedance to prevent surges, leading to increased manufacturing costs and space requirements, hindering miniaturization.

Method used

A surge recovery structure is designed with a housing made of non-metallic material, incorporating resistors and resistor-to-wiring capacitances to form a surge recovery path with lower impedance than paths through ground or thundercloud, utilizing metal portions within the housing for additional resistance.

Benefits of technology

This approach reduces manufacturing costs and prevents surge-related issues while maintaining compactness, even with non-metallic housings, by creating an efficient surge recovery path with reduced impedance.

✦ Generated by Eureka AI based on patent content.

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Abstract

To provide a surge recovery structure that is suppressed from rising in cost even when a housing including a non-metal material is used, electrical machinery equipment for aircraft that comprises the surge recovery structure, and electrical machinery equipment for wind power generation that comprises the surge recovery structure.SOLUTION: In electrical machinery equipment 10 comprising an inverter device 11, a surge recovery path 61 which extends from a load 23 to the load 23 via load floating capacitance 51, a resistor 31, resistor-wiring capacitance 41, and an inverter 17 is constituted as a surge recovery structure. The resistor 31 of the surge recovery path 61 is so set that in a high-frequency band of several kHz to tens of MHz that a main frequency component of a surge has, the impedance when the surge flows through the surge recovery path 61 is lower than the impedance when the surge flows to the ground.SELECTED DRAWING: Figure 1
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Description

[Technical Field]

[0001] The present disclosure relates to a surge recovery structure, an aircraft electrical device, and a wind power generation electrical device. [Background technology]

[0002] One example of a power conversion device is an inverter device. The inverter device has the function of converting AC having a certain voltage and frequency into DC, and then converting the DC into AC having a desired voltage and frequency. Electrical equipment equipped with such an inverter device is provided with a structure for recovering surges generated inside and outside the inverter device (Patent Document 1 and Patent Document 2).

[0003] In particular, Patent Document 1 proposes a structure in which, in a motor drive system that drives a motor connected via a cable to the output end of an inverter device, a grounding wire is connected to the housing of the inverter device in order to reduce conductive noise such as surges, thereby preventing surges from escaping to the ground. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3648123 (JP Patent Publication No. 2001-286152) [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-39376 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional surge recovery structures, in order to prevent the surge (conductive noise) from escaping to the ground, the inverter device's housing is used in conjunction with a grounding wire, creating a path with lower impedance than if the surge were to flow through the ground.

[0006] However, in some cases, the enclosure is made of a non-metallic material such as carbon fiber reinforced plastic. The conductivity of carbon fiber reinforced plastic is approximately one thousandth of that of metal. Therefore, when using an enclosure made of a non-metallic material, it is difficult to form a path with lower impedance than when the surge flows through the ground, simply by using the enclosure and a grounding wire.

[0007] Furthermore, when a housing containing a non-metallic material is used, surge protection components with high resistance must be provided to prevent surges caused by the impedance of the housing containing a non-metallic material from being applied to the inverter device and the load, which may increase manufacturing costs.In addition, it is necessary to secure space for installing such surge protection components, which may hinder miniaturization.

[0008] The present disclosure has been made to solve problems that arise in recovering surges when a housing containing non-metallic materials is used, and one object is to provide a surge recovery structure with reduced manufacturing costs that can recover surges even when a housing containing non-metallic materials is used, another object is to provide electrical equipment for aircraft that is equipped with such a surge recovery structure, and yet another object is to provide electrical equipment for wind power generation that is equipped with such a surge recovery structure. [Means for solving the problem]

[0009] The surge recovery structure according to the present disclosure includes a housing, a power supply, an inverter, a load, wiring, one or more resistors, and a resistor-to-wiring capacitance. The housing includes a non-metallic material having a first conductivity and is electrically connected to at least one of the ground and a thundercloud. The power supply, the inverter, and the load are each housed within the housing. The wiring electrically connects the power supply and the inverter. The one or more resistors are electrically connected to the load and have a second conductivity higher than the first conductivity. The resistor-to-wiring capacitance is interposed between the resistor and the wiring and electrically connects the resistor and the wiring. A surge recovery path is formed from the load via the resistor, the resistor-to-wiring capacitance, and the inverter to the load. A first impedance of the surge recovery path is smaller than a second impedance of a path from the load to at least one of the ground and the thundercloud, via the capacitance between at least one of the ground and the thundercloud and the wiring, and via the inverter to the load. The resistor includes a housing-to-wiring capacitance that is interposed between the housing and the wiring and electrically connects the housing and the wiring. The housing includes a non-metallic portion formed from a non-metallic material and a metal portion formed from a metallic material. The resistor is electrically connected between the load and the metal portion. The housing-to-wiring capacitance includes a metal portion-to-wiring capacitance.

[0010] The electrical equipment for an aircraft according to the present disclosure is installed on an aircraft and includes the surge recovery structure described above. The housing has a reinforcement structure of the aircraft. The resistor includes the reinforcement structure.

[0011] The present disclosure provides an electric device for wind power generation that is mounted on a wind power generating plant and includes the surge recovery structure described above. The housing includes a nacelle that houses a wind power generator. The resistor includes the nacelle. Another surge recovery structure according to the present disclosure includes a housing, a power supply, an inverter, a load, wiring, one or more resistors, and a resistor-to-wiring capacitance. The housing is formed from a non-metallic material having a first conductivity and is electrically connected to at least one of the ground and a thundercloud. The power supply, the inverter, and the load are each housed within the housing. The wiring electrically connects the power supply and the inverter. The one or more resistors are electrically connected to the load and have a second conductivity higher than the first conductivity. The resistor-to-wiring capacitance is interposed between the resistor and the wiring and electrically connects the resistor and the wiring. A surge recovery path is formed from the load via the resistor, the resistor-to-wiring capacitance, and the inverter to the load. A first impedance of the surge recovery path is smaller than a second impedance of a path from the load to at least one of the ground and the thundercloud, via the capacitance between at least one of the ground and the thundercloud and the wiring, and via the inverter to the load. [Effects of the Invention]

[0012] The surge recovery structure according to the present disclosure provides a surge recovery path that runs from a load through a resistor, a resistor-to-wiring capacitance, and an inverter to the load. The first impedance of the surge recovery path is smaller than a second impedance of a path that runs from the load to at least one of the ground and a thundercloud, the capacitance between at least one of the ground and a thundercloud and the wiring, and the inverter to the load. This allows for a surge recovery structure with reduced manufacturing costs to be obtained for electrical equipment having a housing containing non-metallic materials.

[0013] According to the aircraft electrical equipment of the present disclosure, by being provided with the surge recovery structure, it is possible to obtain aircraft electrical equipment with reduced manufacturing costs.

[0014] According to the electric equipment for wind power generation according to the present disclosure, by being provided with the surge recovery structure, it is possible to obtain an electric equipment for wind power generation with reduced manufacturing costs. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram including a circuit diagram showing the configuration of an electric device equipped with a surge recovery structure according to a first embodiment. [Figure 2] FIG. 2 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. [Figure 3] FIG. 10 is a diagram including a circuit diagram showing a surge recovery path as a comparative example in the embodiment. [Figure 4] FIG. 3 is a first diagram schematically illustrating an example of the structure of a resistor in the embodiment. [Figure 5] FIG. 2 is a second diagram schematically illustrating an example of the structure of a resistor in the embodiment. [Figure 6] FIG. 3 is a third diagram schematically illustrating an example of the structure of a resistor in the embodiment. [Figure 7] FIG. 4 is a fourth diagram schematically illustrating an example of the structure of a resistor in the embodiment. [Figure 8] FIG. 10 is a characteristic diagram showing a change in voltage over time as a comparative example, for explaining the surge reduction effect in the embodiment. [Figure 9] FIG. 10 is a characteristic diagram showing a change in voltage over time, for explaining the surge reduction effect in the embodiment. [Figure 10] 10 is a diagram including a circuit diagram showing the configuration of an electric device equipped with a surge recovery structure according to a second embodiment. FIG. [Figure 11] 3A to 3C are diagrams schematically showing examples of the structure of resistors in the embodiment; [Figure 12]FIG. 10 is a diagram including a circuit diagram showing the configuration of an electric device equipped with a surge recovery structure according to a third embodiment. [Figure 13] FIG. 2 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. [Figure 14] FIG. 10 is a perspective view showing an aircraft equipped with an aircraft electrical device according to a fourth embodiment. [Figure 15] 2 is a diagram including a circuit diagram showing the configuration of an aircraft electrical device equipped with a surge recovery structure in the embodiment. FIG. [Figure 16] FIG. 2 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. [Figure 17] FIG. 10 is a diagram including a circuit diagram showing a surge recovery path as a comparative example in the embodiment. [Figure 18] FIG. 11 is a perspective view showing a wind turbine generator equipped with electrical equipment for wind power generation according to a fifth embodiment. [Figure 19] FIG. 2 is a diagram including a circuit diagram showing the configuration of an electrical device for wind power generation equipped with a surge recovery structure in the embodiment. [Figure 20] FIG. 10 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. [Figure 21] FIG. 10 is a diagram including a circuit diagram showing a surge recovery path as a comparative example in the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Embodiment 1 A surge recovery structure for an electrical device 10 having an inverter device 11 according to a first embodiment will be described. As shown in Fig. 1, the inverter device 11 includes a DC power supply 15, an inverter 17, and a load 23. The inverter 17 and the load 23 are electrically connected. The driving of the load 23 is controlled by the inverter 17. The inverter 17 is configured, for example, by a switching element and a diode as a semiconductor element.

[0017] The power supply 15 and the inverter 17 are electrically connected by wiring 19. The wiring 19 includes a first wiring 19a and a second wiring 19b. The positive electrode of the power supply 15 and the inverter 17 are electrically connected by the first wiring 19a. The negative electrode of the power supply 15 and the inverter 17 are electrically connected by the second wiring 19b. The inverter 17 and the load 23 are electrically connected by a shielded cable 27. The shielded cable 27 has a shielded wire 27a.

[0018] The power supply 15, the inverter 17, and the load 23 are housed in a housing 13. The housing 13 includes a non-metallic material such as carbon fiber reinforced plastic. Furthermore, the power supply 15 and the inverter 17 are housed in an inverter housing 21. The load 23 is housed in a load housing 25.

[0019] The load 23 and the load housing 25 are electrically connected by a ground wire 35a. The load housing 25 and the housing 13 are electrically connected by a ground wire 35b. The inverter housing 21 and the housing 13 are electrically connected by a ground wire 35c.

[0020] The housing 13 is electrically connected to a reference potential constituted by the ground 39 or a thundercloud via an equivalent impedance 37 formed by a wiring or an arc. The ground 39 and the wiring 19 are also electrically connected via a ground-to-wiring capacitance 47. The ground-to-wiring capacitance 47 includes a ground-to-first wiring capacitance 47a and a ground-to-second wiring capacitance 47b.

[0021] A resistor 31 electrically connected to the load 23 is disposed within the inverter housing 21. In this inverter device 11, the load 23 and the resistor 31 are electrically connected via a load stray capacitance 51 and a connection wire 29 that electrically connects the load housing 25 and the resistor 31. The connection wire 29 is connected to one end of the resistor 31. The load stray capacitance 51 is a stray capacitance formed between the windings of a motor assumed as the load 23 and the frame of the motor.

[0022] The other end of the resistor 31 is electrically connected to the wiring 19 via a resistor-to-wiring capacitance 41. The resistor-to-wiring capacitance 41 has a resistor-to-first wiring capacitance 41a and a resistor-to-second wiring capacitance 41b. The other end of the resistor 31 is electrically connected to the first wiring 19a via the resistor-to-first wiring capacitance 41a. The other end of the resistor 31 is electrically connected to the second wiring 19b via the resistor-to-second wiring capacitance 41b.

[0023] The housing 13 and the wiring 19 are electrically connected via a housing-to-wiring capacitance 43. The housing-to-wiring capacitance 43 includes a housing-to-first wiring capacitance 43a and a housing-to-second wiring capacitance 43b. The inverter housing 21 and the wiring 19 are electrically connected via an inverter housing-to-wiring capacitance 49. The inverter housing-to-wiring capacitance 49 includes an inverter housing-to-first wiring capacitance 49a and an inverter housing-to-second wiring capacitance 49b.

[0024] The resistor-to-wiring capacitance 41, the housing-to-wiring capacitance 43, and the inverter housing-to-wiring capacitance 49 are preferably electrostatic capacitances such as ceramic capacitors or film capacitors, but may also be stray capacitances that arise due to the structure.

[0025] As shown in Fig. 2, in an electric device 10 including the above-described inverter device 11, a surge recovery path 61 is formed as a surge recovery structure, which runs from the load 23 through the load stray capacitance 51, the resistor 31, the resistor-to-wiring capacitance 41, and the inverter 17 to the load 23 (see the thick solid line). Note that, to avoid complexity in the drawing, a solid line is typically drawn for one of the three phases of the inverter 17. This also applies to the corresponding drawings described later.

[0026] Here, we will explain the resistor 31 (resistance value) in the surge recovery path 61. The resistor 31 (resistance value) in the surge recovery path 61 is set so that the impedance when a surge flows through the surge recovery path 61 is lower than the impedance when the surge flows through the ground in the high frequency band of several kHz to several tens of MHz, which is the main frequency component of the surge.

[0027] Specifically, resistor 31 is set so that the impedance of surge recovery path 61 is lower than the impedance of the path (see thick dotted line) from load 23 via ground wire 35a, ground wire 35b, housing 13, earth 39 or thundercloud, earth-to-wiring capacitance 47, and inverter 17 to load 23, as shown in Figure 3.

[0028] As a result, even if the housing 13 is made of a non-metallic material such as carbon fiber reinforced plastic or plastic, which has a conductivity several thousandths or less than that of metal, it is possible to prevent surges from becoming large, and it is possible to prevent surge countermeasure components from becoming too large, resulting in an inexpensive surge recovery structure.

[0029] Next, a specific structural example of the resistor 31 will be described. As shown in Fig. 4 or 5, a heat sink 55 that dissipates heat generated from a semiconductor element 53 or the like may be used as the resistor 31. Fig. 4 shows a case where the heat sink 55 is housed inside the inverter housing 21. Fig. 5 shows a case where the heat sink 55 is arranged outside the inverter housing 21.

[0030] 6, a spacer 57 and a shield plate 56 disposed on a substrate 54 may be used as the resistor 31. In FIG. 6, the shield plate 56 is disposed on the substrate 54 with the spacer 57 interposed therebetween so as to cover the semiconductor element 53 and the like.

[0031] 7, a ground pattern 58 (ground pattern) provided on a substrate 54 may be used as the resistor 31. Also, as shown in each of FIGS. 5 to 7, the shielded wire 27a of the shielded cable 27 may be electrically connected.

[0032] Next, the surge reduction effect of the surge recovery path 61 (surge recovery structure) in the electric device 10 described above was evaluated by electromagnetic analysis of a surge when a lightning current was applied to the housing 13.

[0033] First, the conditions for the electromagnetic analysis will be explained. A lightning current waveform defined by the aircraft lightning test standard (SAE APR5412-B) was applied to the housing 13, which includes a non-metallic material. The housing-to-wiring capacitance 43 between the inverter 17 and the housing 13 was set to 100 pF per phase. The load stray capacitance 51 was also set to 10 nF. Furthermore, the housing 13 was made of carbon fiber reinforced plastics (CFRP), which had the lowest conductivity in the thickness direction, and the conductivity was set to 5.58 × 10 2 It was assumed that S / m.

[0034] Next, a characteristic diagram obtained by performing an electromagnetic analysis of a surge under these conditions will be described. As shown in Fig. 8 (comparative example), it was found that a surge having a peak value of about -10 kV appeared at the position of the inverter device 11. In contrast, as shown in Fig. 9, when the surge recovery path 61 was provided, a surge having a peak value of about -8 kV appeared, and it was confirmed that the surge could be suppressed better than in the comparative example.

[0035] In the above-described electrical device 10, a DC power supply was used as the power supply 15, but the surge recovery path 61 having the resistor 31 can also be applied when converting an AC power supply to a DC power supply. Furthermore, although the above-described example is one in which the load 23 is housed in the load housing 25 and the load 23 and the load housing 25 are electrically connected by the ground wire 35a, the load housing 25 is not necessarily required, and in this case, the ground wire 35a is not required. Furthermore, while a metal inverter housing 21 is typically used as the inverter housing 21, an inverter housing 21 made of a non-metallic material such as plastic may also be used.

[0036] Embodiment 2 The above-described electric device 10 has been described as using one resistor 31. Here, an electric device 10 including a plurality of resistors 31 will be described.

[0037] 10, the electrical device 10 includes a resistor 31a and a resistor 31b as the resistor 31. As an example of a specific structure of the two resistors 31, a configuration in which two heat sinks 52 are electrically connected in parallel is shown in FIG.

[0038] 10 and 11, one end of the resistor 31a is electrically connected to the connection wire 29. The other end of the resistor 31a is electrically connected to the wiring 19 via a resistor-to-wiring capacitance 41. The resistor-to-wiring capacitance 41 has a resistor-to-first wiring capacitance 41a and a resistor-to-second wiring capacitance 41b.

[0039] One end of resistor 31b is electrically connected to connection line 29. The other end of resistor 31b is electrically connected to wiring 19 via resistor-wiring capacitance 41. Resistor-wiring capacitance 41 has capacitance 41c and capacitance 41d.

[0040] The resistors 31 (31a, 31b) are set so that the impedance of a surge recovery path 61, which runs from the load 23 through the load stray capacitance 51, the resistors 31 (31a, 31b), the resistor-to-wiring capacitance 41 (41a, 41b, 41c, 41d) and the inverter 17 to the load 23, is lower than the impedance when the surge flows through the ground (see the thick dotted line in Figure 3). Note that the rest of the configuration is the same as that of the electrical device 10 shown in Figure 1, so the same members are given the same symbols and their description will not be repeated unless necessary.

[0041] In the above-described electrical device 10, a plurality of resistors 31 are electrically connected in parallel. When the resistor 31 is composed of a plurality of resistors 31 (for example, N resistors 31), the impedance of the resistors 31 as a whole is reduced to 1 / N. This makes it possible to suppress surges even when a housing 13 including a non-metallic material having a conductivity that is one thousandth or less of that of metal is used. It also makes it possible to prevent surge protection components from becoming larger. Examples of non-metallic materials having a conductivity that is one thousandth or less of that of metal include carbon fiber reinforced plastic and plastic.

[0042] Embodiment 3 Here, an electric device using a housing containing a non-metallic material in which a metal portion and a non-metallic portion are specified will be described.

[0043] 12, in electrical device 10, housing 13 containing a non-metallic material is specified as having metal portion 13a and non-metal portion 13b. Metal portion 13a functions as a resistor. One end of metal portion 13a and the other end of resistor 31 are electrically connected by connecting wire 30.

[0044] The other end of the metal portion 13a and the wiring 19 are electrically connected via a housing-to-wiring capacitance 45. The housing-to-wiring capacitance 45 has a housing-to-first wiring capacitance 45a and a housing-to-second wiring capacitance 45b. The other end of the metal portion 13a and the first wiring 19a are electrically connected via the housing-to-first wiring capacitance 45a. The other end of the metal portion 13a and the second wiring 19b are electrically connected via the housing-to-second wiring capacitance 45b.

[0045] The non-metallic portion 13b and the wiring 19 are electrically connected via a housing-to-wiring capacitance 45. The housing-to-wiring capacitance 45 includes a housing-to-first wiring capacitance 45c and a housing-to-second wiring capacitance 45d. The non-metallic portion 13b and the first wiring 19a are electrically connected via the housing-to-first wiring capacitance 45c. The non-metallic portion 13b and the second wiring 19b are electrically connected via the housing-to-second wiring capacitance 45d.

[0046] As shown in Fig. 13, in the above-described electric device 10, the surge recovery path 61 serving as a surge recovery structure includes a surge recovery path 61a and a surge recovery path 61b. The surge recovery path 61a is a path that runs from the load 23 to the load 23 via the load stray capacitance 51, the resistor 31, the resistor-to-wiring capacitance 41 (41a, 41b), and the inverter 17. The surge recovery path 61b is a path that runs from the load 23 to the load 23 via the load stray capacitance 51, the resistor 31, the metal part 13a, the housing-to-wiring capacitance 45 (45a, 45b), and the inverter 17. The resistor 31 is set so that the impedance of the surge recovery path 61 is lower than the impedance when the surge flows through the ground (see the thick dotted line in Fig. 3) in the high frequency band of several kHz to several tens of MHz, which is the main frequency component of the surge.

[0047] The rest of the configuration is similar to that of electrical device 10 shown in FIG. 1, so the same components are given the same reference numerals and descriptions thereof will not be repeated unless necessary.

[0048] In the above-described electric device 10, the surge collection path 61 includes the metal part 13a of the housing 13. This makes it possible to reduce the number of new resistors 31 to be provided in the surge collection path 61, thereby reducing the production cost of the surge collection structure (surge collection path 61).

[0049] Embodiment 4 Here, an aircraft electrical device mounted on an aircraft will be described as an electrical device equipped with a surge recovery structure. As shown in Fig. 14, a reinforcing structure 73 including a frame 74 and stringers 75 is employed in the fuselage of an aircraft 71 (see Fig. 15). The frame 74 is arranged along the longitudinal direction of the fuselage. The stringers 75 are arranged along the circumferential direction of the fuselage so as to intersect with the frame 74.

[0050] In an aircraft electrical device 72, a reinforcing structure 73 is applied as a resistor in a surge recovery path as a surge recovery structure. As shown in Fig. 15 , the reinforcing structure 73 formed by a frame 74 and a stringer 75 includes a metal portion 73a and a non-metal portion. In the reinforcing structure 73, the metal portion 73a is applied as the resistor 31. The reinforcing structure 73 corresponds to the housing 13 including a non-metal material shown in Fig. 1 etc. An inverter housing 21 and a load housing 25 are housed within the reinforcing structure 73 as the housing 13.

[0051] A connection wire 29 is electrically connected to one end of the metal portion 73a serving as the resistor 31. The other end of the metal portion 73a is electrically connected to the wiring 19 via a resistor-to-wiring capacitance 45. The housing-to-wiring capacitance 45 has a housing-to-first wiring capacitance 45a and a housing-to-second wiring capacitance 45b. Note that the rest of the configuration is substantially the same as the configuration of the electrical device 10 shown in FIG. 1 etc., and therefore the same members are designated by the same reference numerals, and their description will not be repeated unless necessary.

[0052] As shown in Figure 16, in the above-mentioned aircraft electrical equipment 72, a surge recovery path 61 is formed as a surge recovery structure, which runs from the load 23 through the load stray capacitance 51, the metal part 73a as the resistor 31, the housing-to-wiring capacitance 45 and the inverter 17 to the load 23.

[0053] The impedance of the surge recovery path 61 is set to be lower than the impedance of a path 161a (see thick dotted line) that runs from the load 23 to the load 23 via the load stray capacitance 51, the equivalent impedance 37, the ground 39 or thundercloud, the ground-to-wiring capacitance 47, and the inverter 17 in the aircraft electrical equipment as a comparative example shown in Figure 17. The ground-to-wiring capacitance 47 has a ground-to-first wiring capacitance 47a and a ground-to-second wiring capacitance 47b.

[0054] The impedance of the surge recovery path 61 is set to be lower than the impedance of a path 161b (see the thick dotted line) that runs from the load 23 to the load 23 via the load stray capacitance 51, the non-metal 73b, the housing-to-wiring capacitance 45, and the inverter 17 in the aircraft electrical equipment as a comparative example shown in Fig. 17. The housing-to-wiring capacitance 45 has a housing-to-first wiring capacitance 45c and a housing-to-second wiring capacitance 45d.

[0055] In the above-mentioned aircraft electrical equipment 72, by using the metal part 73a in the reinforcing structure 73 as the resistor 31, the surge recovery path 61 as a surge recovery structure can be constructed inexpensively without preparing a new resistor.

[0056] As described in the first embodiment, a heat sink, a shield wire of a shielded cable, a shield plate, or the like may be applied as the resistor 31 in the surge recovery path 61 in addition to the reinforcing structure 73. In this case, it is possible to prevent the surge current from flowing through the reinforcing structure, and to prevent deterioration of the reinforcing structure due to application of the surge current.

[0057] When a lightning surge is applied to an aircraft, the equivalent impedance 37 due to the wiring or arc is the arc resistance between the aircraft and the thundercloud. Generally speaking, when the enclosure is grounded via an inductance component or resistance due to the wiring, the surge (voltage) increases depending on the grounding impedance of the enclosure. Furthermore, when the enclosure is grounded, even if the impedance of the enclosure itself is high, surge problems are unlikely to occur as long as the impedance from the enclosure to the ground point is low.

[0058] In the above-described aircraft electrical equipment 72, the surge recovery path 61 can also recover surges in the following systems: That is, the housing 13 (reinforcement structure 73) is electrically connected to a reference potential constituted by the earth 39 or a thundercloud via an equivalent impedance 37 formed by wiring or an arc, and the housing 13 can also recover surges in systems where the potential is not at ground potential in the high frequency band of the surge, from several kHz to several tens of MHz.

[0059] As a surge recovery structure (surge recovery path 61), when the inverter housing 21 is made of metal and the load housing 25 is also made of metal, it is conceivable to electrically connect the inverter housing 21 and the load housing 25 by a ground wire.

[0060] However, in the case of aircraft electrical equipment, the inverter and the load may be located approximately 30 m apart, which may pose a problem in terms of weight and cost of the grounding wire that electrically connects the inverter housing and the load housing.

[0061] In contrast, in the surge recovery path 61 of the aircraft electrical equipment 72 described above, by using metal parts (structures) such as frames and stringers that serve as reinforcing structures as resistors 31, the number of newly added parts can be minimized, thereby achieving weight reduction and cost reduction.

[0062] When CFRP is used in aircraft, a method is known in which a metal mesh layer is inserted into the CFRP to ensure lightning resistance. In such a structure, a combination of a metal mesh layer and a reinforcing structure (frame and stringer) may be used as the resistor 31. This reduces the number of newly installed resistors, contributing to a reduction in the production cost of the surge recovery structure (surge recovery path).

[0063] Embodiment 5 Here, as an example of electrical equipment equipped with a surge recovery structure, an electrical equipment for wind power generation mounted on a wind turbine generator will be described. As shown in Fig. 18, a nacelle 83 that houses a generator and other components is mounted on a wind turbine generator 81. The nacelle 83 includes a metal portion 83a and a non-metal portion 83b.

[0064] In the wind power generation electric equipment 82, a metal part 83a in a nacelle 83 is used as a resistor in a surge recovery path as a surge recovery structure. As shown in Fig. 19, the nacelle 83 corresponds to the housing 13 including a non-metallic material shown in Fig. 1 etc. The inverter housing 21 and the load housing 25 are housed inside the nacelle 83 as the housing 13.

[0065] A connection wire 29 is electrically connected to one end of the metal portion 83a serving as the resistor 31. The other end of the metal portion 83a is electrically connected to the wiring 19 via a resistor-to-wiring capacitance 45. The resistor-to-wiring capacitance 45 has a resistor-to-first wiring capacitance 45a and a resistor-to-second wiring capacitance 45b. Note that the rest of the configuration is substantially the same as the configuration of the electrical device 10 shown in FIG. 1 etc., and therefore the same members are designated by the same reference numerals, and their description will not be repeated unless necessary.

[0066] As shown in Figure 20, in the above-mentioned wind power generation electrical equipment 82, a surge recovery path 61 is formed as a surge recovery structure, which runs from the load 23 through the load stray capacitance 51, the metal part 83a as the resistor 31, the housing-to-wiring capacitance 45 and the inverter 17 to the load 23.

[0067] The impedance of surge recovery path 61 is set to be lower than the impedance of path 161a (see thick dotted line) that runs from load 23 to load 23 via load stray capacitance 51, equivalent impedance 37, ground, ground-to-wiring capacitance 47, and inverter 17 in the wind power generation electric equipment as a comparative example shown in Fig. 21. Ground-to-wiring capacitance 47 has ground-to-first wiring capacitance 47a and ground-to-second wiring capacitance 47b.

[0068] The impedance of surge recovery path 61 is set to be lower than the impedance of path 161b (see thick dotted line) that runs from load 23 to load 23 via load stray capacitance 51, non-metallic part 83b, housing-to-wiring capacitance 45 (45c, 45d) and inverter 17 in the wind power generation electric equipment as a comparative example shown in Fig. 21. The housing-to-wiring capacitance 45 includes housing-to-first wiring capacitance 45c and housing-to-second wiring capacitance 45d.

[0069] In the above-mentioned wind power generation electrical equipment 82, by using the metal part 83a in the nacelle 83 as the resistor 31, it is possible to inexpensively construct a surge recovery path 61 as a surge recovery structure without preparing a new resistor.

[0070] When a lightning surge is applied to the wind power generation electrical equipment, the equivalent impedance 37 due to the wiring or arc becomes the wiring inductance between the wind power generation electrical equipment and the ground. In the above-mentioned wind power generation electrical equipment 82, the surge can be collected by the surge collection path 61 even in the following system: That is, the housing 13 (nacelle 83) is electrically connected to the reference potential constituted by the ground via the equivalent impedance 37 due to the wiring or arc, and the surge can be collected even in a system in which the housing 13 does not become the ground potential in the high frequency band of the surge, from several kHz to several tens of MHz.

[0071] The surge recovery structures described in each embodiment can be combined in various ways as needed. In addition, although each embodiment has been described with reference to a case where the power source 15 is a DC power source, the power source 15 may be a three-phase three-wire or three-phase four-wire power source using an AC rectifier circuit.

[0072] The embodiments disclosed herein are examples and are not intended to be limiting. The scope of the present disclosure is defined by the claims, not the scope described above, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0073] The present disclosure includes the following aspects. (Appendix 1) a housing including a non-metallic material having a first electrical conductivity and electrically connected to at least one of the ground and the thundercloud; a power supply, an inverter, and a load, each housed within the housing; Wiring electrically connecting the power supply and the inverter; one or more resistors electrically connected to the load and having a second conductivity higher than the first conductivity; a resistor-to-wiring capacitance interposed between the resistor and the wiring and electrically connecting the resistor and the wiring; Equipped with a surge recovery path is configured from the load through the resistor, the resistor-wiring capacitance, and the inverter to the load; A surge recovery structure, wherein a first impedance of the surge recovery path is smaller than a second impedance of a path from the load to at least one of the earth and the thundercloud, a capacitance between at least one of the earth and the thundercloud and the wiring, and the inverter to the load.

[0074] (Appendix 2) The inverter is A circuit board; a power semiconductor element mounted on the circuit board; 2. The surge recovery structure of claim 1, including:

[0075] (Appendix 3) the inverter has a heat sink that dissipates heat generated from the power semiconductor element, 3. The surge recovery structure of claim 2, wherein the resistor includes the heat sink.

[0076] (Appendix 4) the inverter has a conductive shield plate disposed on the circuit board via a conductive spacer so as to cover the circuit board; 4. The surge recovery structure according to claim 2, wherein the resistor includes the conductive spacer and the conductive shield plate.

[0077] (Appendix 5) the inverter has a ground pattern formed on the circuit board; 5. The surge recovery structure according to claim 2, wherein the resistor includes the ground pattern.

[0078] (Appendix 6) a shielded cable including a shielded wire, which electrically connects the inverter and the load; 6. The surge recovery structure according to any one of claims 2 to 5, wherein the resistor includes the shielded wire.

[0079] (Appendix 7) the resistors include one resistor and another resistor, 7. The surge recovery structure according to any one of claims 1 to 6, wherein the one resistor and the other resistor are electrically connected in parallel.

[0080] (Appendix 8) a housing-to-wiring capacitance interposed between the housing and the wiring and electrically connecting the housing and the wiring; The housing includes: a non-metallic portion formed from the non-metallic material; a metal part formed from a metal material; Including, the resistor is electrically connected between the load and the metal portion, 8. The surge recovery structure according to claim 1, wherein the capacitance between the housing and the wiring includes capacitance between the metal part and the wiring.

[0081] (Appendix 9) the capacitance between the housing and the wiring includes capacitance between the non-metallic part and the wiring, a ground wire electrically connecting the load and the housing; 9. The surge recovery structure of claim 8, wherein the resistor is set so that the first impedance is lower than a third impedance of a path from the load through the ground wire, the housing, the reference potential of the housing, the capacitance between the non-metallic part and the wiring, and the inverter to the load.

[0082] (Appendix 10) a metal housing that houses the inverter; 10. The surge recovery structure according to any one of claims 1 to 9, wherein the metal housing is housed within the housing.

[0083] (Appendix 11) An aircraft electrical device that is installed on an aircraft and includes the surge recovery structure according to any one of appendices 1 to 10, the enclosure comprises a reinforcement structure of an aircraft; The resistor includes the reinforcing structure.

[0084] (Appendix 12) 12. The aircraft electrical equipment according to claim 11, wherein the housing is electrically connected via a resistor to a reference potential constituted by either the ground or the thundercloud.

[0085] (Appendix 13) An electric device for wind power generation that is mounted on a wind power generation system and has the surge recovery structure according to any one of appendices 1 to 10, the housing includes a nacelle that houses a wind turbine generator; The resistor includes the nacelle.

[0086] (Appendix 14) the wind turbine generator is installed on the ground, 14. The wind power generating electrical equipment according to claim 13, wherein the housing is electrically connected to a reference potential of the ground by a grounding wiring that electrically connects the ground and the nacelle. [Industrial Applicability]

[0087] The present disclosure is effectively utilized for surge protection of electrical equipment that uses a housing containing a non-metallic material. [Explanation of symbols]

[0088] 10 Electrical equipment, 11 Inverter device, 13 Housing, 13a Metal part, 13b Non-metal part, 15 Power supply, 17 Inverter, 19 Wiring, 19a First wiring, 19b Second wiring, 21 Inverter housing, 23 Load, 25 Load housing, 27 Shielded cable, 27a Shielded wire, 29, 30 Connecting wire, 31, 31a, 31b Resistor, 35a, 35b, 35c Ground wire, 37 Equivalent impedance, 39 Ground, 41 Resistor-wiring capacitance, 41a Resistor-first wiring capacitance, 41b Resistor-second wiring capacitance, 41c Resistor-first wiring capacitance, 41d Resistor-second wiring capacitance, 43 Housing-wiring capacitance, 43a Housing-first wiring capacitance, 43b Capacitance between the enclosure and the second wiring, 45. Capacitance between the enclosure and the wiring, 45a. Capacitance between the metal part and the first wiring, 45b. Capacitance between the metal part and the second wiring, 45c. Capacitance between the non-metal part and the first wiring, 45d. Capacitance between the non-metal part and the second wiring, 47. Capacitance between the ground and the wiring, 47a. Capacitance between the ground and the first wiring, 47b. Capacitance between the ground and the second wiring, 49. Capacitance between the inverter enclosure and the wiring, 49a. Capacitance between the inverter enclosure and the first wiring, 49b. Capacitance between the inverter enclosure and the second wiring, 51. Load capacitance, 53. Semiconductor element, 54. Circuit board, 55. Heat sink, 56. Shield plate, 57. Spacer, 58. Grounding pattern, 61. Surge recovery structure, 71. Aircraft, 72. Aircraft electrical equipment, 73. Reinforcement structure, 73a. Metal part, 73b. Non-metal part, 74. Frame, 75 Stringer, 81 Wind turbine generator, 82 Electrical equipment for wind turbine generator, 83 Nacelle, 83a Metallic parts, 83b Non-metallic parts.

Claims

1. a housing including a non-metallic material having a first electrical conductivity and electrically connected to at least one of the ground and the thundercloud; a power supply, an inverter, and a load, each housed within the housing; Wiring electrically connecting the power supply and the inverter; one or more resistors electrically connected to the load and having a second conductivity higher than the first conductivity; a resistor-to-wiring capacitance interposed between the resistor and the wiring and electrically connecting the resistor and the wiring; Equipped with a surge recovery path is configured from the load through the resistor, the resistor-wiring capacitance, and the inverter to the load; a first impedance of the surge recovery path is smaller than a second impedance of a path from the load to at least one of the earth and the thundercloud, a capacitance between at least one of the earth and the thundercloud and the wiring, and the inverter to the load; a housing-to-wiring capacitance interposed between the housing and the wiring and electrically connecting the housing and the wiring; The housing includes: a non-metallic portion formed from the non-metallic material; a metal part formed from a metal material; Including, the resistor is electrically connected between the load and the metal portion, A surge recovery structure, wherein the housing-to-wiring capacitance includes a metal part-to-wiring capacitance.

2. The inverter is A circuit board; a power semiconductor element mounted on the circuit board; The surge recovery structure of claim 1 , comprising:

3. the inverter has a heat sink that dissipates heat generated from the power semiconductor element, The surge recovery structure of claim 2 , wherein the resistor includes the heat sink.

4. the inverter has a conductive shield plate disposed on the circuit board via a conductive spacer so as to cover the circuit board; The surge recovery structure according to claim 2 , wherein the resistor includes the conductive spacer and the conductive shield plate.

5. the inverter has a ground pattern formed on the circuit board; The surge recovery structure according to claim 2 , wherein the resistor includes the ground pattern.

6. a shielded cable including a shielded wire, which electrically connects the inverter and the load; The surge recovery structure according to claim 2 , wherein the resistor includes the shielded wire.

7. the resistors include one resistor and another resistor, 2. The surge recovery structure according to claim 1, wherein said first resistor and said second resistor are electrically connected in parallel.

8. the capacitance between the housing and the wiring includes capacitance between the non-metallic part and the wiring, a ground wire electrically connecting the load and the housing; 2. The surge recovery structure of claim 1, wherein the resistor is set so that the first impedance is lower than a third impedance of a path from the load through the ground wire, the housing, the reference potential of the housing, the capacitance between the non-metallic part and the wiring, and the inverter to the load.

9. a metal housing that houses the inverter; The surge recovery structure of claim 1 , wherein the metal housing is housed within the housing.

10. An aircraft electrical device that is installed on an aircraft and includes the surge recovery structure according to any one of claims 1 to 9, the enclosure comprises a reinforcement structure of an aircraft; The resistor includes the reinforcing structure.

11. The electrical equipment for an aircraft according to claim 10 , wherein the housing is electrically connected to a reference potential constituted by either the ground or the thundercloud via a resistor.

12. An electrical device for wind power generation that is mounted on a wind power generation device and includes the surge recovery structure according to any one of claims 1 to 9, the housing includes a nacelle that houses a wind turbine generator; The resistor includes the nacelle.

13. the wind turbine generator is installed on the ground, The electric equipment for wind power generation according to claim 12 , wherein the housing is electrically connected to a reference potential of the earth by a ground wiring that electrically connects the earth and the nacelle.

14. A housing formed from a non-metallic material having a first electrical conductivity and electrically connected to at least one of the earth and a thundercloud; a power supply, an inverter, and a load, each housed within the housing; Wiring electrically connecting the power supply and the inverter; one or more resistors electrically connected to the load and having a second conductivity higher than the first conductivity; a resistor-to-wiring capacitance interposed between the resistor and the wiring and electrically connecting the resistor and the wiring; Equipped with a surge recovery path is configured from the load through the resistor, the resistor-wiring capacitance, and the inverter to the load; A surge recovery structure, wherein a first impedance of the surge recovery path is smaller than a second impedance of a path from the load to at least one of the earth and the thundercloud, or between at least one of the earth and the thundercloud and the wiring, and through the inverter to the load.

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