JP7770245B2 - Surge recovery structures, electrical equipment for aircraft and electrical equipment for wind power generation - Google Patents

Description

This disclosure relates to surge recovery structures, aircraft electrical equipment, and wind power generation electrical equipment.

One example of a power conversion device is an inverter device. An inverter device converts AC having a certain voltage and frequency into DC, and then converts that DC into AC having a desired voltage and frequency. Electrical equipment equipped with such an inverter device is provided with a structure that recovers surges that occur inside and outside the inverter device (Patent Document 1 and Patent Document 2).

In particular, Patent Document 1 proposes a structure for a motor drive system that drives a motor connected via a cable to the output end of an inverter device, in which a ground wire is connected to the inverter device's housing to reduce conductive noise such as surges, preventing surges from escaping to the ground.

Japanese Patent No. 3648123 (Japanese Patent Laid-Open No. 2001-286152) JP 2014-39376 A

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.

However, there are cases where the enclosure contains a non-metallic material, such as carbon fiber reinforced plastic. The conductivity of carbon fiber reinforced plastic is said to be about one thousandth of that of metal. For this reason, when using an enclosure containing a non-metallic material, simply using the enclosure in conjunction with a grounding wire makes it difficult to create a path with lower impedance than when the surge flows through the ground.

Furthermore, when using a housing containing non-metallic materials, surge protection components with high resistance capacity must be installed to prevent surges generated by the impedance of the housing containing non-metallic materials from being applied to the inverter device and load, which could increase manufacturing costs. Furthermore, it is necessary to secure space for installing such surge protection components, which could hinder miniaturization.

This disclosure has been made to solve the problems that arise in recovering surges when using a housing containing non-metallic materials. One objective is to provide a surge recovery structure with reduced manufacturing costs that can recover surges even when using a housing containing non-metallic materials. Another objective is to provide electrical equipment for aircraft that includes such a surge recovery structure. A further objective is to provide electrical equipment for wind power generation that includes such a surge recovery structure.

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.

The aircraft electrical equipment according to the present disclosure is installed on an aircraft and equipped with the surge recovery structure described above. The housing has a reinforcing structure for the aircraft. The resistor includes the reinforcing structure.

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.

The surge recovery structure disclosed herein 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 the second impedance of the path that runs from the load to at least one of the earth and a thundercloud, the capacitance between at least one of the earth and a thundercloud and the wiring, and the inverter to the load. This makes it possible to obtain a surge recovery structure with reduced manufacturing costs for electrical equipment having a housing containing non-metallic materials.

The aircraft electrical equipment disclosed herein is equipped with the surge recovery structure, making it possible to obtain aircraft electrical equipment with reduced manufacturing costs.

The wind power generation electrical equipment disclosed herein is equipped with the surge recovery structure, making it possible to obtain wind power generation electrical equipment with reduced manufacturing costs.

1 is a diagram including a circuit diagram showing the configuration of an electrical device equipped with a surge recovery structure according to a first embodiment; FIG. 2 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. FIG. 10 is a diagram including a circuit diagram showing a surge recovery path as a comparative example in the embodiment. FIG. 2 is a first diagram schematically illustrating an example of the structure of a resistor in the embodiment; FIG. 2 is a second diagram schematically illustrating an example of the structure of a resistor in the embodiment. FIG. 10 is a third diagram schematically illustrating an example of the structure of a resistor in the embodiment. FIG. 4 is a fourth diagram schematically illustrating an example of the structure of a resistor in the embodiment. 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. FIG. 10 is a characteristic diagram showing a change in voltage over time, for explaining the surge reduction effect in the embodiment. 10 is a diagram including a circuit diagram showing the configuration of an electrical device equipped with a surge recovery structure according to a second embodiment. FIG. 3A to 3C are diagrams schematically showing examples of the structure of resistors in the embodiment; FIG. 10 is a diagram including a circuit diagram showing the configuration of an electrical device equipped with a surge recovery structure according to a third embodiment. FIG. 2 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. FIG. 10 is a perspective view showing an aircraft equipped with an aircraft electrical device according to a fourth embodiment. 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. FIG. 2 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. FIG. 10 is a diagram including a circuit diagram showing a surge recovery path as a comparative example in the embodiment. FIG. 11 is a perspective view showing a wind power generation system equipped with electrical equipment for wind power generation according to a fifth embodiment. 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. FIG. 10 is a diagram including a circuit diagram showing a surge recovery path in the embodiment. FIG. 10 is a diagram including a circuit diagram showing a surge recovery path as a comparative example in the embodiment.

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.

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 terminal of the power supply 15 and the inverter 17 are electrically connected by the first wiring 19a. The negative terminal 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.

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

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.

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 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.

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 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 the stray capacitance formed between the windings of the motor, which is assumed to be the load 23, and the motor frame.

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.

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.

Note that 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 arising from the structure.

As shown in Figure 2, in an electrical device 10 equipped with the inverter device 11 described above, a surge recovery structure is formed, which includes a surge recovery path 61 that 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 cluttering 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 below.

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 a surge.

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 line 35a, ground line 35b, housing 13, earth 39 or thundercloud, earth-to-wiring capacitance 47, and inverter 17 to load 23, as shown in Figure 3.

This means that 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 also possible to prevent surge protection components from becoming too large, resulting in an inexpensive surge recovery structure.

Next, a specific structural example of the resistor 31 will be described. As shown in Figure 4 or Figure 5, a heat sink 55 that dissipates heat generated by a semiconductor element 53 or the like may be used as the resistor 31. Figure 4 shows a case in which the heat sink 55 is housed within the inverter housing 21. Figure 5 shows a case in which the heat sink 55 is arranged outside the inverter housing 21.

Also, as shown in Figure 6, a spacer 57 and a shield plate 56 arranged on a substrate 54 may be used as the resistor 31. Figure 6 shows a case in which the shield plate 56 is arranged so as to cover the semiconductor element 53 and the like, with the spacer 57 interposed between the substrate 54 and the shield plate 56.

Furthermore, as shown in FIG. 7, a ground pattern 58 (ground pattern) provided on the 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.

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

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 included 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 set to 10 nF. Furthermore, the housing 13 was made of carbon fiber reinforced plastics (CFRP), which is assumed to have the lowest conductivity in the thickness direction of 5.58 x ¹⁰² S/m.

Next, we will explain the characteristics diagram obtained by performing an electromagnetic analysis of surges under these conditions. As shown in Figure 8 (comparative example), it was found that a surge with a peak value of approximately -10 kV appeared at the position of the inverter device 11. In contrast, as shown in Figure 9, when the surge recovery path 61 was included, a surge with a peak value of approximately -8 kV appeared, confirming that the surge was more effectively suppressed than in the comparative example.

In the above-described electrical device 10, a DC power supply was used as the power supply 15. However, the surge recovery path 61 having the resistor 31 can also be applied when converting AC power to DC power. Furthermore, while the example was described 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 a 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.

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.

As shown in FIG. 10, the electrical device 10 is provided with resistors 31a and 31b as resistors 31. As an example of the specific structure of the two resistors 31, FIG. 11 shows a configuration in which two heat sinks 52 are electrically connected in parallel.

As shown in Figures 10 and 11, a connection line 29 is electrically connected to one end of the resistor 31a. 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.

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.

The resistors 31 (31a, 31b) are set so that, in the high-frequency band of several kHz to several tens of MHz, which is the main frequency component of surges, the impedance of the surge recovery path 61, which runs from the load 23 through the load stray capacitance 51, the resistors 31 (31a, 31b), the resistor-to-line 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). The rest of the configuration is the same as that of the electrical device 10 shown in Figure 1, so the same components are designated by the same reference numerals and their descriptions will not be repeated unless necessary.

In the electrical device 10 described above, multiple resistors 31 are electrically connected in parallel. When the resistor 31 is composed of multiple (e.g., 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 using a housing 13 containing a non-metallic material with a conductivity that is one thousandth or less of that of metal. It also prevents surge protection components from becoming larger. Examples of non-metallic materials with a conductivity that is one thousandth or less of that of metal include carbon fiber reinforced plastic and plastic.

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.

As shown in FIG. 12, in the electrical device 10, a housing 13 containing a non-metallic material is identified as having a metal portion 13a and a non-metal portion 13b. The metal portion 13a functions as a resistor. One end of the metal portion 13a and the other end of the resistor 31 are electrically connected by a connection wire 30.

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 includes 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.

The non-metallic portion 13b and the wiring 19 are electrically connected via the 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.

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

Other than this, the configuration is the same as that of the electrical device 10 shown in Figure 1, so the same components are given the same reference numerals and their descriptions will not be repeated unless necessary.

In the electrical device 10 described above, the surge recovery path 61 includes the metal part 13a of the housing 13. This reduces the number of new resistors 31 required in the surge recovery path 61, thereby reducing the production costs of the surge recovery structure (surge recovery path 61).

Embodiment 4.
Here, an aircraft electrical device mounted on an aircraft will be described as an example of 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 disposed along the longitudinal direction of the fuselage. The stringers 75 are disposed along the circumferential direction of the fuselage so as to intersect with the frame 74.

In aircraft electrical equipment 72, reinforcing structure 73 is used as a resistor in the surge recovery path as a surge recovery structure. As shown in FIG. 15 , reinforcing structure 73 formed by frame 74 and stringer 75 includes a metal portion 73a and a non-metal portion. In reinforcing structure 73, metal portion 73a is used as resistor 31. Reinforcing structure 73 corresponds to housing 13 including non-metallic material shown in FIG. 1 etc. An inverter housing 21 and a load housing 25 are housed within reinforcing structure 73 as housing 13.

A connecting 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 includes a housing-to-first wiring capacitance 45a and a housing-to-second wiring capacitance 45b. The rest of the configuration is substantially the same as the configuration of the electrical device 10 shown in Figure 1, etc., so the same components are designated by the same reference numerals and their descriptions will not be repeated unless necessary.

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

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

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

In the aircraft electrical equipment 72 described above, by using the metal portion 73a of the reinforcing structure 73 as the resistor 31, the surge recovery path 61 can be inexpensively constructed as a surge recovery structure without the need for a new resistor.

In addition to the reinforcing structure 73, the resistor 31 in the surge recovery path 61 may also be a heat sink, a shielded wire of a shielded cable, a shield plate, or the like, as described in embodiment 1. In this case, it is possible to prevent surge current from flowing through the reinforcing structure, thereby preventing deterioration of the reinforcing structure due to the application of surge current.

When a lightning surge is applied to an aircraft, the equivalent impedance 37 due to the wiring or arc becomes the arc resistance value between the aircraft and the thundercloud. Generally speaking, if the enclosure is grounded via an inductance component or resistance due to the wiring, the surge (voltage) will increase depending on the grounding impedance of the enclosure. Furthermore, if 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.

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

As a surge recovery structure (surge recovery path 61), if the inverter housing 21 is made of metal and the load housing 25 is also made of metal, it is possible to electrically connect the inverter housing 21 and the load housing 25 via a ground wire.

However, in the case of aircraft electrical equipment, the inverter and load may be located approximately 30 meters apart. In such cases, the weight and cost of the grounding wire that electrically connects the inverter housing and the load housing can be expected to become an issue.

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 the resistor 31, it is possible to minimize the number of newly added parts, thereby achieving weight reduction and cost reduction.

When CFRP is typically used in aircraft, a known method is to insert a metal mesh layer into the CFRP to ensure lightning resistance. In such a structure, a resistor 31 may be applied that combines a metal mesh layer with a reinforcing structure (frame and stringer). This reduces the number of newly installed resistors, contributing to a reduction in the production costs of surge recovery structures (surge recovery paths).

Embodiment 5.
Here, as an example of electrical equipment having 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 wind turbine generator 81 is mounted with a nacelle 83 that houses a generator and other components. The nacelle 83 includes a metal portion 83a and a non-metal portion 83b.

In the wind power generation electrical equipment 82, the metal portion 83a of the nacelle 83 is used as a resistor in the surge recovery path as a surge recovery structure. As shown in Figure 19, the nacelle 83 corresponds to the housing 13 containing non-metallic materials shown in Figure 1, etc. The inverter housing 21 and the load housing 25 are housed within the nacelle 83 as the housing 13.

A connecting 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 includes a resistor-to-first wiring capacitance 45a and a resistor-to-second wiring capacitance 45b. The rest of the configuration is substantially the same as the configuration of the electrical device 10 shown in Figure 1, etc., so the same components are designated by the same reference numerals and their descriptions will not be repeated unless necessary.

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

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

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

In the wind power generation electrical equipment 82 described above, by using the metal part 83a of 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.

When a lightning surge is applied to 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 wind power generation electrical equipment 82 described above, the surge recovery path 61 allows the surge to be recovered even in the following system. That is, the housing 13 (nacelle 83) is electrically connected to the reference potential formed by the ground via the equivalent impedance 37 due to the wiring or arc, and the surge can be recovered even in a system in which the housing 13 is not at ground potential in the high-frequency band of several kHz to several tens of MHz of the surge.

The surge recovery structures described in each embodiment can be combined in various ways as needed. Furthermore, while each embodiment describes a case where the power source 15 is DC, the power source 15 may also be AC, such as a three-phase three-wire or three-phase four-wire power source, and may use a rectifier circuit.

The embodiments disclosed herein are illustrative and not 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 of the claims.

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, or between at least one of the earth and the thundercloud and the wiring, and through the inverter to the load.

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

(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.

(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.

(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.

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

(Appendix 7)
the resistors include one resistor and another resistor,
7. The surge recovery structure according to claim 1, wherein the one resistor and the other resistor are electrically connected in parallel.

(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 portion formed from a metal material;
the resistor is electrically connected between the load and the metal portion,
The surge recovery structure according to any one of claims 1 to 7, wherein the capacitance between the housing and the wiring includes capacitance between the metal part and the wiring.

(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.

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

(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.

(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.

(Appendix 13)
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 appendices 1 to 10,
the housing includes a nacelle that houses a wind turbine generator;
The resistor includes the nacelle.

(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 ground wiring that electrically connects the ground and the nacelle.

This disclosure can be effectively used to protect electrical equipment from surges using housings containing non-metallic materials.

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 housing and second wiring, 45: Capacitance between housing and wiring, 45a: Capacitance between metal part and first wiring, 45b: Capacitance between metal part and second wiring, 45c: Capacitance between non-metal part and first wiring, 45d: Capacitance between non-metal part and second wiring, 47: Capacitance between ground and wiring, 47a: Capacitance between ground and first wiring, 47b: Capacitance between ground and second wiring, 49: Capacitance between inverter housing and wiring, 49a: Capacitance between inverter housing and first wiring, 49b: Capacitance between inverter housing and second wiring, 51: Load capacitance, 53: Semiconductor element, 54: Substrate, 55: Heat sink, 56: Shield plate, 57: Spacer, 58: Grounding pattern, 61: Surge recovery structure, 71: Aircraft, 72: Electrical equipment for aircraft, 73: Reinforcement structure, 73a: Metal part, 73b: Non-metal part, 74 Frame, 75 Stringer, 81 Wind power generation device, 82 Electrical equipment for wind power generation, 83 Nacelle, 83a Metal part, 83b Non-metal part.

Claims (14)

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 . The inverter is
A circuit board;
2. The surge recovery structure according to claim 1, further comprising a power semiconductor element mounted on said circuit board. 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. 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. 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. 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. 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. 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. a metal housing that houses the inverter;
The surge recovery structure of claim 1 , wherein the metal housing is housed within the housing. 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. 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. An electrical device for wind power generation that is mounted on a wind power generation system 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. 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. a housing formed from 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, or between at least one of the earth and the thundercloud and the wiring, and through the inverter to the load.