ELECTRIC POWER SYSTEM AND MOVING OBJECT

An electric power system of a moving object includes a first polyphase rotating electric machine, a second polyphase rotating electric machine, a first polyphase terminal unit, a second polyphase terminal unit, a first polyphase cable, and a second polyphase cable. Each of the first and second polyphase terminal units includes a first phase terminal, a second phase terminal, and a third phase terminal. The first distance is smaller than the second distance that is smaller than the third distance. The fourth distance is smaller than the fifth distance that is smaller than the sixth distance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-047970 filed on Mar. 24, 2023, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an electric power system and a moving object.

Description of the Related Art

In recent years, research and development have been conducted on electric power systems that contribute to energy efficiency in order to ensure that more people have access to affordable, reliable, sustainable and modern energy.

For example, US 2020/0115045 A1 discloses an aircraft. The aircraft obtains a propulsion force by rotors driven by electric power generated by a generator.

SUMMARY OF THE INVENTION

US 2020/0115045 A1 does not specifically describe the layout of the components including cables. To provide an electric power system and a moving object capable of performing wiring suitably while suppressing cost.

An object of the present invention is to solve the above-described problems.

A first aspect of the present invention is an electric power system including: a rotating electric machine unit including a first polyphase rotating electric machine and a second polyphase rotating electric machine; a pair of a first polyphase terminal unit and a second polyphase terminal unit disposed on both sides of a region positioned in a first direction of the rotating electric machine unit so as to be spaced from each other in a second direction intersecting the first direction; a first polyphase cable connecting the first polyphase terminal unit and the first polyphase rotating electric machine; and a second polyphase cable connecting the second polyphase terminal unit and the second polyphase rotating electric machine, wherein each of the first polyphase terminal unit and the second polyphase terminal unit includes a first phase terminal, a second phase terminal and a third phase terminal arranged along the first direction, a first distance from the first phase terminal of the first polyphase terminal unit to the first polyphase rotating electric machine is smaller than a second distance from the second phase terminal of the first polyphase terminal unit to the first polyphase rotating electric machine, the second distance is smaller than a third distance from the third phase terminal of the first polyphase terminal unit to the first polyphase rotating electric machine, a fourth distance from the third phase terminal of the second polyphase terminal unit to the second polyphase rotating electric machine is smaller than a fifth distance from the second phase terminal of the second polyphase terminal unit to the second polyphase rotating electric machine, and the fifth distance is smaller than a sixth distance from the first phase terminal of the second polyphase terminal unit to the second polyphase rotating electric machine.

A second aspect of the present invention is an electric power system including: a rotating electric machine unit including a first rotating electric machine and a second rotating electric machine; a pair of a first terminal unit and a second terminal unit disposed on both sides of a region positioned in a first direction relative to the rotating electric machine unit so as to be spaced from each other in a second direction intersecting the first direction; a first cable connecting the first terminal unit and the first rotating electric machine; and a second cable connecting the second terminal unit and the second rotating electric machine, wherein each of the first terminal unit and the second terminal unit includes a grounding terminal and an ungrounded terminal arranged along the first direction, a distance from the grounding terminal of the first terminal unit to the first rotating electric machine is smaller than a distance from the ungrounded terminal of the first terminal unit to the first rotating electric machine, and a distance from the ungrounded terminal of the second terminal unit to the second rotating electric machine is smaller than a distance from the grounding terminal of the second terminal unit to the second rotating electric machine.

A third aspect of the present invention is a moving object including the above-described electric power system.

According to the present invention, wiring can be performed suitably while suppressing the cost.

DETAILED DESCRIPTION OF THE INVENTION

An electric power system10A and a moving object12according to an embodiment of the present invention will be described below with reference to the drawings. As shown inFIG.1, a moving object12according to the present embodiment is, for example, an aircraft (flying object). The aircraft is an electric vertical take-off and landing (eVTOL) aircraft, but is not limited thereto. For example, the moving object12may be a ship, a vehicle, or the like. The description hereinafter will be made in a case where the electric power system10A is mounted on the moving object12, although the present invention is not limited thereto.

The moving object12includes a fuselage14. The front-rear direction of the fuselage14and the left-right direction of the fuselage14are orthogonal to each other. The front-rear direction of the fuselage14corresponds to a first direction herein. The left-right direction of the fuselage14corresponds to a second direction herein. The up-down direction of the fuselage14corresponds to a third direction herein.

The moving object12has eight VTOL rotors16. The VTOL rotors16generate a thrust with respect to the fuselage14, in the upward direction. The moving object12has two cruise rotors18. The cruise rotors18generate a thrust with respect to the fuselage14, in the forward direction of the fuselage14.

The moving object12includes the electric power system10A. The electric power system10A is disposed in the fuselage14. As shown inFIG.2, the fuselage14includes a system placement section20rearward of a cabin (not shown), in the front-rear direction of the fuselage14. The system placement section20includes a first housing chamber22and a second housing chamber24.

The first housing chamber22and the second housing chamber24are aligned along the front-rear direction of the fuselage14. The first housing chamber22is positioned in the front direction of the fuselage14than the second housing chamber24. A partition wall26is provided between the first housing chamber22and the second housing chamber24. The second housing chamber24is divided into a first sub-chamber30and a second sub-chamber32by a partition wall28. The first sub-chamber30and the second sub-chamber32are arranged in the left-right direction of the fuselage14. The partition wall28extends on a center line L0in the left-right direction of the fuselage14.

The electric power system10A includes a first polyphase rotating electric machine34a, a second polyphase rotating electric machine34b, a first power control unit (first power conversion device)36a, a second power control unit (second power conversion device)36b, and a main junction box38. Hereinafter, the first power control unit36amay be referred to as a first PCU36a, and the second power control unit36bmay be referred to as a second PCU36b. The main junction box38may be referred to as an MJB38.

The first polyphase rotating electric machine34ais a three-phase alternating current rotating electric machine. A first engine (not shown) is connected to the first polyphase rotating electric machine34a. The first engine is, for example, a gas turbine engine, but is not limited thereto. The first polyphase rotating electric machine34afunctions as an electric power generator that generates electric power by being driven by the first engine. The first polyphase rotating electric machine34acan also function as a motor for driving a compressor of the first engine.

The first PCU36aand the first polyphase rotating electric machine34aare electrically connected by a first polyphase cable40a. The first PCU36ais a first power conversion device that converts a three-phase alternating current transmitted from the first polyphase rotating electric machine34avia the first polyphase cable40ainto a direct current. The electric power converted into the direct current by the first PCU36ais supplied to the MJB38. For example, a battery (not shown) is electrically connected to the MJB38. Further, load devices such as the VTOL rotors16, the cruise rotors18, and the like are electrically connected to the MJB38.

A second engine (not shown) is connected to the second polyphase rotating electric machine34b. The second engine may have the same configuration as the first engine. The second polyphase rotating electric machine34bfunctions as an electric power generator that generates electric power by being driven by the second engine. The second polyphase rotating electric machine34bcan also function as a motor for driving a compressor of the second engine.

The second PCU36band the second polyphase rotating electric machine34bare electrically connected by a second polyphase cable40b. The second PCU36bis a second power conversion device that converts three-phase alternating current transmitted from the second polyphase rotating electric machine34bvia the second polyphase cable40binto direct current. The electric power converted into the direct current by the second PCU36bis supplied to the MJB38.

The first polyphase rotating electric machine34ais disposed in the first sub-chamber30. The second polyphase rotating electric machine34bis disposed in the second sub-chamber32. The first polyphase rotating electric machine34aand the second polyphase rotating electric machine34bare positioned close to the partition wall28. The partition wall28is interposed between the first polyphase rotating electric machine34aand the second polyphase rotating electric machine34bin the left-right direction of the fuselage14. The first polyphase rotating electric machine34aand the second polyphase rotating electric machine34bare electrically separated from each other by the partition wall28.

The first polyphase rotating electric machine34aincludes a three-phase power terminal unit42. The power terminal unit42includes a first phase power terminal44, a second phase power terminal46, and a third phase power terminal48. The first phase power terminal44, the second phase power terminal46, and the third phase power terminal48are in alignment with each other along the left-right direction (second direction) of the fuselage14. The first phase power terminal44, the second phase power terminal46, and the third phase power terminal48are arranged in this order leftward in the left-right direction of the fuselage14.

The second polyphase rotating electric machine34bhas the same configuration as the first polyphase rotating electric machine34a. This can reduce the number of types of components of the electric power system10A, and thus can reduce the manufacturing cost of the electric power system10A. In the second polyphase rotating electric machine34b, the same constituent elements as those of the first polyphase rotating electric machine34aare denoted using the same numerals, and the detailed description of the configuration will be omitted.

The first PCU36aand the second PCU36bare disposed in the first housing chamber22. The first PCU36aand the second PCU36bare disposed on both sides of a region50positioned forward of the rotating electric machine unit34including the first polyphase rotating electric machine34aand the second polyphase rotating electric machine34b, in the front-rear direction of the fuselage14. The first PCU36aand the second PCU36bare spaced apart from each other in the left-right direction (second direction).

The first PCU36ais positioned forward of the first polyphase rotating electric machine34aand rightward of the second polyphase rotating electric machine34bin the front-rear direction and the left-right direction of the fuselage14. In other words, the first PCU36ais positioned on the right side of the center line L0of the fuselage14. The first PCU36ais adjacent to a right sidewall52of the fuselage14.

The second PCU36bis positioned forward of the second polyphase rotating electric machine34band leftward of the first polyphase rotating electric machine34ain the front-rear direction and the left-right direction of the fuselage14. In other words, the second PCU36bis positioned on the left side of the center line L0of the fuselage14. The second PCU36bis adjacent to a left sidewall54of the fuselage14.

As shown inFIGS.5and6, the first PCU36aincludes a housing56, a polyphase terminal unit58, and a DC terminal unit60. The housing56is formed in a rectangular parallelepiped shape. The polyphase terminal unit58is provided on the upper surface56aof the housing56. The DC terminal unit60is provided on the lower surface56bof the housing56.

As shown inFIGS.2,3and6, the polyphase terminal unit58includes a first phase terminal62, a second phase terminal64and a third phase terminal66. The first phase terminal62, the second phase terminal64, and the third phase terminal66are spaced apart from each other. The first phase terminal62, the second phase terminal64, and the third phase terminal66are aligned at intervals along the front-rear direction (first direction) of the fuselage14.

In the first polyphase terminal unit58a, which is the polyphase terminal unit58of the first PCU36a, the first phase terminal62, the second phase terminal64, and the third phase terminal66are aligned in this order forward in the front-rear direction of the fuselage14. In the first polyphase terminal unit58a, the second phase terminal64is positioned forward of the first phase terminal62, and the third phase terminal66is positioned forward of the second phase terminal64, in the front-rear direction of the fuselage14.

As shown inFIG.2, a first distance L1, which is the shortest distance from the first phase terminal62of the first polyphase terminal unit58ato the first polyphase rotating electric machine34a, is smaller than a second distance L2, which is the shortest distance from the second phase terminal64of the first polyphase terminal unit58ato the first polyphase rotating electric machine34a. The second distance L2is smaller than a third distance L3, which is the shortest distance from the third phase terminal66of the first polyphase terminal unit58ato the first polyphase rotating electric machine34a. The first polyphase terminal unit58aand the power terminal unit42of the first polyphase rotating electric machine34aare positioned at substantially the same level in the up-down direction of the fuselage14(seeFIG.6).

As shown inFIG.4, the first polyphase cable40aincludes a first phase wire (first phase wiring)68, a second phase wire (second phase wiring)70, a third phase wire (third phase wiring)72, and a sheath member74. The first phase wire68includes a first phase conductor68aand an insulating covering68bfor the first phase conductor68a. The second phase wire70includes a second phase conductor70aand an insulating covering70bfor the second phase conductor70a. The third phase wire72includes a third phase conductor72aand an insulating covering72bfor the third phase conductor72a.

As shown inFIG.2, the first phase wire68connects the first phase power terminal44and the first phase terminal62to each other. The second phase wire70connects the second phase power terminal46and the second phase terminal64to each other. The third phase wire72connects the third phase power terminal48and the third phase terminal66to each other. The sheath member74is a tubular member for bundling the first phase wire68, the second phase wire70, and the third phase wire72together. The sheath member74penetrates the partition wall26.

In the first polyphase rotating electric machine34a, the first phase power terminal44, the second phase power terminal46, and the third phase power terminal48are arranged in this order from the right side to the left side of the fuselage14. Therefore, in the first polyphase cable40a, the first phase wire68, the second phase wire70, and the third phase wire72are arranged in this order from the right side to the left side of the fuselage14. The first distance L1is smaller than the second distance L2, and the second distance L2is smaller than the third distance L3. Thus, in the first polyphase cable40a, the first phase wire68, the second phase wire70and the third phase wire72do not need to be three-dimensionally crossed.

In the first polyphase terminal unit58a, the first phase terminal62, the second phase terminal64, and the third phase terminal66are not necessarily in alignment with each other and may be deviated in the left-right direction of the fuselage14as long as the first phase wire68, the second phase wire70, and the third phase wire72do not need to be three-dimensionally crossed.

As shown inFIG.6, the DC terminal unit60includes a positive terminal78and a negative terminal80. The positive terminal78and the negative terminal80are arranged in the front-rear direction (first direction) of the fuselage14with a space therebetween. The positive terminal78and the negative terminal80are electrically connected to a lower part of the MJB38via cables or the like (not shown). To an upper part of the MJB38, the battery and the load devices are electrically connected via cables (not shown). That is, the electric power converted into a direct current by the first PCU36ais supplied to the MJB38from the lower part thereof through the positive terminal78and the negative terminal80, and then provided to the battery and the load devices from the upper part of the MJB38.

As shown inFIGS.2,3,5, and7, the second PCU36bhas the same configuration as the first PCU36a. This can reduce the number of types of components of the electric power system10A, and thus can reduce the cost of the electric power system10A. In the second PCU36b, the same constituent elements as those of the first PCU36aare denoted using the same numerals, and the detailed description thereof will be omitted.

As shown inFIGS.2and3, the second PCU36bhas a configuration in which the first PCU36aturns 180° in the front-rear direction of the fuselage14.

As shown inFIGS.2,3and7, in the second polyphase terminal unit58b, which is the polyphase terminal unit58of the second PCU36b, the first phase terminal62, the second phase terminal64, and the third phase terminal66are arranged in this order rearward in the front-rear direction of the fuselage14. In the second polyphase terminal unit58b, the second phase terminal64is positioned forward of the third phase terminal66, and the first phase terminal62is positioned forward of the second phase terminal64, in the front-rear direction of the fuselage14. The order of the terminals of the second polyphase terminal unit58bis opposite to the order of the terminals of the first polyphase terminal unit58a.

As shown inFIG.2, a fourth distance L4, which is the shortest distance from the third phase terminal66of the second polyphase terminal unit58bto the second polyphase rotating electric machine34b, is smaller than a fifth distance L5, which is the shortest distance from the second phase terminal64of the second polyphase terminal unit58bto the second polyphase rotating electric machine34b. The fifth distance L5is smaller than a sixth distance L6, which is the shortest distance from the first phase terminal62of the second polyphase terminal unit58bto the second polyphase rotating electric machine34b.

The second polyphase cable40bhas the same configuration as the first polyphase cable40a. The sheath member74of the second polyphase cable40bpenetrates the partition wall26.

In the second polyphase rotating electric machine34b, the first phase power terminal44, the second phase power terminal46, and the third phase power terminal48are arranged in this order leftward in the left-right direction of the fuselage14. Therefore, in the second polyphase cable40b, the first phase wire68, the second phase wire70, and the third phase wire72are arranged in this order leftward in the left-right direction of the fuselage14. In the second polyphase terminal unit58b, the first phase wire68, the second phase wire70and the third phase wire72are arranged such that the fourth distance L4is smaller than the fifth distance L5, and the fifth distance L5is smaller than the sixth distance L6. Thus, in the second polyphase cable40b, the first phase wire68, the second phase wire70and the third phase wire72do not need to be three-dimensionally crossed.

In the second polyphase terminal unit58b, the first phase terminal62, the second phase terminal64, and the third phase terminal66are not necessarily in alignment with each other and may be deviated in the left-right direction of the fuselage14as long as the first phase wire68, the second phase wire70, and the third phase wire72do not need to be three-dimensionally crossed.

As shown inFIGS.6and7, the positions of the positive terminal78and the negative terminal80in the second PCU36bare inverted from those in the first PCU36a, in the front-rear direction of the fuselage14.

As shown inFIGS.2,3, and5, the MJB38is disposed in the region50between the first PCU36aand the second PCU36b. The center line of the MJB38is positioned on the center line L0of the fuselage14, in the left-right direction of the fuselage14. The first PCU36ais attached to the right side surface of the MJB38. The second PCU36bis attached to the left side surface of the MJB38.

As shown inFIG.5, a first cooling unit82ais provided between the MJB38and the first PCU36a. A second cooling unit82bis provided between the MJB38and the second PCU36b. Cooling water is running through the first cooling unit82aand the second cooling unit82b. The first PCU36aand the second PCU36beach have an internal switching element, and heat is generated from the switching element and the like. The first PCU36ais cooled by the first cooling unit82a. The second PCU36bis cooled by the second cooling unit82b.

As described above, according to the present embodiment, the three-phase wires of the first polyphase cable40ado not need to be three-dimensionally crossed, and the three-phase wires of the second polyphase cable40bdo not need to be three-dimensionally crossed. Therefore, even when relatively thick conductor wires are used as the three-phase wires of the first polyphase cable40aand the second polyphase cable40b, the wiring can be performed as desired. Moreover, since the first PCU36aand the second PCU36bhaving the same configuration may be arranged in such a manner that the second PCU36bis simply turned 180° to face the first PCU36a, the cost of the electric power system10A can be suppressed.

Modifications

Next, a description will be given concerning the advantageous effects of an electric power system10B. In the present modification, the same constituent elements as those described in the aforementioned electric power system10A are denoted using the same reference numerals, and detailed description of such features will be omitted.

As shown inFIG.8, the electric power system10B includes a first rotating electric machine90a, a second rotating electric machine90b, a first PCU92a, a second PCU92b, and a MJB38. The first rotating electric machine90ais configured similarly to the first polyphase rotating electric machine34adescribed above, except that it is, for example, a single-phase alternating current rotating electric machine. The second rotating electric machine90bhas the same configuration as the first rotating electric machine90a. A power terminal unit96of each of the first rotating electric machine90aand the second rotating electric machine90bincludes a grounding power terminal98and an ungrounded power terminal100.

The first PCU92aand the second PCU92bare disposed on both sides of a region50positioned forward of a rotating electric machine unit90including the first rotating electric machine90aand the second rotating electric machine90b, in the front-rear direction of the fuselage14. The first PCU92ais configured similarly to the first PCU36adescribed above, except that terminal units102are provided instead of the polyphase terminal unit58. The first terminal unit102a, which is the terminal unit102of the first PCU92a, includes a grounding terminal104and an ungrounded terminal106.

A seventh distance L7, which is the shortest distance from the grounding terminal104of the first terminal unit102ato the first rotating electric machine90a, is smaller than an eighth distance L8, which is the shortest distance from the ungrounded terminal106of the first terminal unit102ato the first rotating electric machine90a. The first terminal unit102ais electrically connected to the power terminal unit96of the first rotating electric machine90athrough a first power cable108a.

The first power cable108aincludes a grounding wire110, an ungrounded wire112, and a sheath member74. The grounding wire110includes a grounded conductor (not shown) and an insulating covering (not shown) covering the grounded conductor. The ungrounded wire112includes an ungrounded conductor (not shown) and an insulating covering (not shown) covering the ungrounded conductor. The grounding wire110connects the grounding power terminal98and the grounding terminal104to each other. The ungrounded wire112connects the ungrounded power terminal100and the ungrounded terminal106to each other.

The second PCU92bhas the same configuration as the first PCU92a. The second PCU92bhas a configuration as the first PCU92ais turned 180° in the front-rear direction of the fuselage14. The second PCU92bhas a second terminal unit102bas the terminal unit102. The order of the terminals in the second terminal unit102bare arranged in a direction opposite to the order of those in the first terminal unit102a.

A ninth distance L9, which is the shortest distance from the ungrounded terminal106of the second terminal unit102bto the second rotating electric machine90b, is smaller than a tenth distance L10, which is the shortest distance from the grounding terminal104of the second terminal unit102bto the second rotating electric machine90b. The second terminal unit102bis electrically connected to the power terminal unit96of the first rotating electric machine90athrough a second power cable108b. The second power cable108bis configured in the same manner as the first power cable108a.

According to such a modification, a plurality of wires of the first power cable108ado not need to be three-dimensionally crossed, and a plurality of wires of the second power cable108bdo not need to be three-dimensionally crossed. Therefore, even when relatively thick conductor wires are used as the wires of the first power cable108aand the second power cable108b, the wiring can be performed as desired. Moreover, since the first PCU92aand the second PCU92bhaving the same configuration are arranged simply by turning 180°, the cost of the electric power system10B can be suppressed.

The above-described electric power system10A may include a first MJB38aand a second MJB38binstead of the MJB38, as shown inFIG.9. The first MJB38ais electrically connected to the first PCU36a. The second MJB38bis electrically connected to the second PCU36b. The casing of the first MJB38aand the casing of the second MJB38bare independent of each other. The first MJB38aand the second MJB38bare disposed in a state of being separated from each other in the left-right direction of the fuselage14. Similarly, the electric power system10B may include a first MJB38aand a second MJB38binstead of the MJB38.

The present embodiment is not limited to the above-described configuration. The electric power system10A may have a configuration suitable for a four-phase or more alternating current.

In addition to the above disclosure, the following Supplementary Notes are further disclosed.

Supplementary Note 1

The electric power system (10A) including: the rotating electric machine unit (34) including the first polyphase rotating electric machine (34a) and the second polyphase rotating electric machine (34b); the pair of the first polyphase terminal unit (58a) and the second polyphase terminal unit (58b) disposed on both sides of the region (50) positioned in the first direction relative to the rotating electric machine unit so as to be spaced from each other in a second direction intersecting the first direction; the first polyphase cable (40a) connecting the first polyphase terminal unit and the first polyphase rotating electric machine; and the second polyphase cable (40b) connecting the second polyphase terminal unit and the second polyphase rotating electric machine, wherein each of the first polyphase terminal unit and the second polyphase terminal unit includes the first phase terminal (62), the second phase terminal (64) and the third phase terminal (66) arranged along the first direction, the first distance (L1) from the first phase terminal of the first polyphase terminal unit to the first polyphase rotating electric machine is smaller than the second distance (L2) from the second phase terminal of the first polyphase terminal unit to the first polyphase rotating electric machine, the second distance is smaller than the third distance (L3) from the third phase terminal of the first polyphase terminal unit to the first polyphase rotating electric machine, the fourth distance (L4) from the third phase terminal of the second polyphase terminal unit to the second polyphase rotating electric machine is smaller than the fifth distance (L5) from the second phase terminal of the second polyphase terminal unit to the second polyphase rotating electric machine, and a fifth distance is smaller than the sixth distance (L6) from the first phase terminal of the second polyphase terminal unit to the second polyphase rotating electric machine.

According to such a configuration, since the pair of polyphase terminal units are disposed on both sides of the region positioned in the first direction relative to the rotating electric machine unit so as to be separated from each other in the second direction intersecting the first direction, the pair of polyphase terminal units can be electrically separated from each other. In addition, in the polyphase terminal unit, the first phase terminal, the second phase terminal, and the third phase terminal are arranged along the first direction, and thus the dimension of the electric power system in the second direction (the direction in which the pair of polyphase terminal units are arranged) can be relatively shortened.

Further, in such an electric power system, by applying the same structure to the connection between the first polyphase rotating electric machine and the first polyphase cable and between the second polyphase rotating electric machine and the second polyphase cable, the manufacturing cost of the electric power system can be suppressed. According to the above configuration, in the first polyphase terminal unit, the first distance is smaller than the second distance, and the second distance is smaller than the third distance. In the second polyphase terminal unit, the fourth distance is smaller than the fifth distance, and the fifth distance is smaller than the sixth distance. Therefore, even when the above-described connection structure is applied to the electric power system, it is not necessary to three-dimensionally cross the wires in each of the first polyphase cable and the second polyphase cable. Therefore, according to such a configuration, even when a relatively thick conductor wire is used for the polyphase wiring of the polyphase cables, the wiring can be performed as desired.

Supplementary Note 2

In the electric power system according to Supplementary Note 1, a power terminal unit (42) of the first polyphase rotating electric machine and the first polyphase terminal unit may be positioned at substantially the same level in a third direction intersecting the first direction and the second direction, and a power terminal unit of the second polyphase rotating electric machine and the second polyphase terminal unit may be positioned at substantially the same level in the third direction.

According to such a configuration, the power terminal unit of the first polyphase rotating electric machine and the first polyphase terminal unit are positioned at substantially the same level in the third direction, and thus the length of the first polyphase cable can be made relatively small. Further, the power terminal unit of the second polyphase rotating electric machine and the second polyphase terminal unit are positioned at substantially the same level in the third direction, and thus the length of the second polyphase cable can be made relatively small.

Supplementary Note 3

The power system according to Supplementary Note 1 or 2 may further include a pair of a first power conversion devices (36a) and a second power conversion device (36b) that are configured to convert an alternating current into a direct current, wherein the first power conversion device (36a) may be equipped with the first polyphase terminal unit, and the second power conversion device (36b) may be equipped with the second polyphase terminal unit.

Supplementary Note 4

The electric power system according to Supplementary Note 3 may further include a junction box (38) disposed in the region and electrically connected to the first power conversion device and the second power conversion device.

According to such a configuration, the junction box can prevent the first power conversion device and the second power conversion device from being electrically connected to each other while making the power system compact.

Supplementary Note 5

In the electric power system according to Supplementary Note 3 or 4, the first power conversion device and the second power conversion device may have the same configuration, and the second polyphase terminal unit of the second power conversion device may be arranged in a manner so that the first power conversion device is turned 180° in the first direction.

According to such a configuration, the first power conversion device and the second power conversion device have the same configuration, and thus the manufacturing cost of the power system can be further reduced.

Supplementary Note 6

The electric power system (10B) including: the rotating electric machine unit (90) including the first rotating electric machine (90a) and the second rotating electric machine (90b); the pair of the first terminal unit (102a) and the second terminal unit (102b) disposed on both sides of the region positioned in the first direction relative to the rotating electric machine unit so as to be spaced from each other in the second direction intersecting the first direction; the first cable (108a) connecting the first terminal unit and the first rotating electric machine; and the second cable (108b) connecting the second terminal unit and the second rotating electric machine, wherein each of the first terminal unit and the second terminal unit includes the grounding terminal (104) and the ungrounded terminal (106) arranged along the first direction, the distance (L7) from the grounding terminal of the first terminal unit to the first rotating electric machine is smaller than the distance (L8) from the ungrounded terminal of the first terminal unit to the first rotating electric machine, and the distance (L9) from the ungrounded terminal of the second terminal unit to the second rotating electric machine is smaller than the distance (L10) from the grounding terminal of the second terminal unit to the second rotating electric machine.

Supplementary Note 7

A moving object (12) includes the electric power system according to any one of Supplementary Notes 1 to 6.

According to such a configuration, it is possible to obtain a moving object in which wiring can be performed without three-dimensional crossing with a reduced manufacturing cost.

Moreover, it should be noted that the present invention is not limited to the embodiments described above, but a variety of configurations may be adopted therein without departing from the essence and gist of the present invention.