WO2019004062A1

WO2019004062A1 - In-wheel motor system and electric automobile

Info

Publication number: WO2019004062A1
Application number: PCT/JP2018/023706
Authority: WO
Inventors: 明生中島
Original assignee: Ntn株式会社
Priority date: 2017-06-28
Filing date: 2018-06-21
Publication date: 2019-01-03
Also published as: JP2019006322A

Abstract

Provided is an in-wheel motor system with which the amount of wiring between an in-wheel motor drive device and an inverter device can be reduced, and a situation in which the in-wheel motor drive device is large and thus difficult to be put into the wheel can be eliminated. In a system in which an in-wheel motor drive device (10) and an inverter device (1) mounted on a vehicle body are connected by wiring, the following are installed in the in-wheel motor drive device (10): an RD converter (2) that converts a detection signal of a resolver (6), which detects the rotation of a motor, to a digital signal; a temperature sensor circuit (18) that processes a detection signal of a motor temperature sensor (11); and a communication circuit (22). A superposing means (28) that superposes a signal on the power source current may be provided.

Description

In-wheel motor system and electric vehicle

Related application

This application claims the priority of Japanese Patent Application No. 2017-125786 filed on June 28, 2017, which is incorporated by reference in its entirety.

The present invention relates to an in-wheel motor system provided with an RD converter (resolver digital converter) that processes resolver signals, and an electric vehicle equipped with the same.

In the in-wheel motor system, a signal cable is provided between the inverter device on the vehicle body and the sensor in the wheel. Sensors in the wheel include a resolver and a temperature sensor, and about 10 wires are used.

In addition to this, an in-wheel motor drive device integrated with a mechanical device has been proposed (Patent Document 1). In this example, since the inverter device and the motor are integrated, the wiring between the inverter device and the motor does not appear outside. Also, a structure of a shielded resolver wiring has been proposed. In this case, although seven wires are required, there are six if no shield is required. (Patent Document 2)

JP, 2013-201878, A JP, 2015-177716, A

The signal cable wired from the vehicle body side to the sensor on the in-wheel motor drive side is always subjected to bending, tension, rotation, etc. force due to vertical vibration by the suspension of the wheel or turning operation in turning, and possibility of cutting There is. For this reason, it is necessary to use a cable having bending resistance as the signal cable.

Also, at both ends or one side of the signal cable, a connector is usually used. The signal cable and connector on the in-wheel motor drive side also need elements of water resistance, oil resistance, high temperature resistance, low temperature resistance and vibration resistance, and especially connectors with 5 cores or more have few commercial products and their selection is difficult It becomes. Therefore, in order to improve the feasibility, it is desirable to reduce the number of wires as much as possible and to use only two to four wires. If wiring is possible using only 2 to 4 electric wires, harnesses and connectors developed for coaxial cables and ABS (anti-lock brake system) can be diverted.

If it demonstrates in an example, FIG. 7 is an example of the electric circuit of the conventional general sensor signal around the inverter apparatus 1 and the in-wheel motor drive device 10. As shown in FIG. The resolver 6 is composed of a resolver stator 4 fixed to a frame (not shown) in the in-wheel motor drive device 10 and a resolver rotor 5 mechanically connected to a motor rotating portion. Signals of the SIN coil 8 and the COS coil 9 induced from the exciting coil 7 by the rotation of the resolver rotor 5 are sent to the inverter device 1 using the sensor signal cable 13. In the inverter device 1, the RD converter 2 processes the signal and transmits it to the CPU 30 in the inverter device 1 as a detection signal of the rotational position of the resolver rotor 5. At this time, the RD converter 2 performs analysis on the basis of the signal REF from the excitation circuit 3 that excites the excitation coil 7. The excitation circuit 3 may be provided independently of the RD converter IC.

A signal from the motor temperature sensor 11 is sent to the inverter device 1 using a sensor signal cable 13. In the inverter device 1, the motor rotation detection position information and the motor temperature information which are processed through the RD converter 2 and the temperature sensor circuit 18 are transmitted to the CPU 30.

The in-wheel motor drive device 10 and the inverter device 1 are connected by the sensor signal cable 13. The sensor signal cable 13 comprises electric wires of six resolver signals (resolver signals) and two electric wires connected to the motor temperature sensor 11. If a shield is required, the number will increase further. Since a plurality of temperature sensors 11 may be disposed, the sensor signal cable 13 is a wire of eight or more.

In the case of an in-wheel motor system, the wiring is required to have water resistance, oil resistance, high temperature resistance, low temperature resistance, vibration resistance, and bending resistance. A connector (not shown) is usually attached to both the in-wheel motor drive device 10 side and the inverter device 1 side, and performances of water resistance, oil resistance, high temperature resistance, low temperature resistance and vibration resistance are required.

In the case of the in-wheel motor drive unit integrated with the mechanical and electrical unit (Patent Document 1), only two signal wires are provided because there is only power supply and communication such as CAN (control area network) between the vehicle side and the inverter unit. That's it. However, since the inverter is installed in the in-wheel motor drive device, the entire device becomes large and the in-wheel motor drive device does not fit in the wheel. Moreover, in the case of air cooling, the cooling performance is limited and it is not suitable for a large output.

SUMMARY OF THE INVENTION An object of the present invention is to provide an in-wheel motor system that requires less wiring between the in-wheel motor drive and the inverter device and does not easily get in the wheel because the in-wheel motor drive is large, and an electric vehicle It is to be.

Hereinafter, the present invention will be described with reference to the reference numerals of the embodiments for the sake of convenience to facilitate understanding.

The in-wheel motor system according to the present invention includes an in-wheel motor drive device 10 having a motor 36 and a bearing 34 for a wheel, and an inverter device 1 installed on the vehicle body to convert direct current power of the battery into alternating current power and to control output. An in-wheel motor system connected by wiring,
RD converter for converting detection signal of resolver 6 for detecting rotation of motor 36 into digital signal, temperature sensor circuit 18 for processing detection signal of temperature sensor 11 for detecting temperature of motor, and RD converter 2 A communication circuit 22 for transmitting an output and an output of the temperature sensor circuit 18 is mounted on the in-wheel motor drive device 10.

According to this configuration, since the RD converter 2, the temperature sensor circuit 18, and the communication circuit 22 are mounted on the in-wheel motor drive device 10, the detection signal of the resolver 6 or the temperature sensor 11 may be sent as it is as an analog signal Differently, it can be digitized and transmitted by serial transmission. Therefore, transmission of signals between the in-wheel motor drive device 10 and the inverter device 1 can be performed with a small number of wires. For example, it can be wired by two electric wires or one shield wire. Water resistance, oil resistance, high temperature resistance, low temperature resistance, vibration resistance, bending resistance performance are required for the wiring between in-wheel motor drive device 10 and inverter device 1, but two electric wires Implementation of performance requirements is facilitated. It also facilitates connector design, manufacture and selection. Also, unlike the configuration in which the entire inverter device 1 is mounted on the in-wheel motor drive device 10, the RD converter 2, the temperature sensor circuit 18, and the communication circuit 22 are mounted on the in-wheel motor drive device 10 1 itself is not mounted, so the in-wheel motor drive 10 does not get stuck in the wheel because it is large.

As the wiring, the communication power transmission line 24 for supplying the power source power of the weak power system output from the inverter device 1 to the in-wheel motor drive device 10 is provided, and the information communication is performed on the current flowing through the communication power transmission line 24. The in-wheel motor drive device 10 may have signal superimposing means for superimposing the above signals, and the inverter device 1 may have signal separating means 29 for separating the signal superimposed on the current. When the signal of the information communication is superimposed on the wiring (communication power transmission line 24) for supplying power to the RD converter 2 and the like as described above, the number of wirings can be further reduced. The wiring is required to have water resistance, oil resistance, high temperature resistance, low temperature resistance, vibration resistance, and bending resistance, but the reduction in the number of wirings facilitates the realization of the required performance. It also facilitates connector design, manufacture and selection.

In the in-wheel motor system of the present invention, the RD converter 2, the temperature sensor circuit 18, and the communication circuit 22 may be provided on a common sensor substrate 19. This makes the wiring and mounting of various electronic elements more compact.

An electric vehicle of the present invention is equipped with the in-wheel motor system of any of the above-described configurations of the present invention. For this reason, the wiring between the in-wheel motor drive device 10 and the inverter device 1 can be reduced, and since the in-wheel motor drive device 10 is large, it does not become difficult to enter the wheel.

Any combination of the at least two configurations disclosed in the claims and / or the description and / or the drawings is included in the invention. In particular, any combination of two or more of the claims is included in the invention.

The invention will be more clearly understood from the following description of the preferred embodiments with reference to the accompanying drawings. However, the embodiments and the drawings are for the purpose of illustration and description only and are not to be taken as limiting the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in multiple drawings indicate the same or corresponding parts.

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual diagram of the electric vehicle carrying the in-wheel motor system which concerns on one Embodiment of this invention. It is a block diagram which shows the basic composition of the same in-wheel motor system. It is an electric circuit diagram of the same in-wheel motor system. It is a circuit diagram of a modification of a sensor signal circuit in the in-wheel motor system. FIG. 6 is an electrical circuit diagram of an in-wheel motor system according to another embodiment of the present invention. It is a sectional view showing an outline of an in-wheel motor drive. It is an electric circuit diagram of a conventional example.

One embodiment of the present invention will be described in conjunction with FIGS. FIG. 1 is a conceptual view showing an example of an electric vehicle equipped with this in-wheel motor system. The electric vehicle is a rear wheel drive vehicle in which left and right wheels 32 serving as rear wheels of a vehicle body 51 are driven by the in-wheel motor drive device 10 respectively. The wheels 33 serving as the front wheels are driven wheels, which are steered wheels steered by the operation of the steering wheel 52. A friction brake 35 is provided for each of the

wheels

32 and 33.

The control system of the whole vehicle will be described. The VCU (vehicle-control-unit) 55 reads an accelerator input which is an operation angle of the accelerator 53 by the driver, converts it into a torque command, and instructs the inverter device 1. The VCU 55 is an ECU (Electronic-control-unit) that performs overall control of the entire vehicle. The inverter device 1 converts the DC power of the battery 56 into three-phase AC by the inverter 1a, and controls the motor 36 of the left and right in-wheel motor drive devices 10 by controlling the power based on the torque command by the motor control circuit 1b. To drive. In this case, although it is also possible to use two inverter devices, the inverter device 1 of this example is a two-axis integrated type and can drive two motors 36. Although the electric vehicle of this example is rear wheel drive, front wheel drive and four wheel drive can also be realized with the same configuration as described above. In the case of four-wheel drive, the inverter device 1 may be provided separately for the front wheels and the rear wheels.

<In-wheel motor drive 10>
For example, as shown in FIG. 6, the in-wheel motor drive device 10 includes a motor 36, a reduction gear 37, and a bearing 34 for a wheel, and a part or all of these are disposed in the wheel 32. The rotation of the motor 36 is transmitted to the wheel 32 via the reduction gear 37, its output member 40, and the hub wheel 34 a which is a rotating wheel of the wheel bearing 34. The brake rotor 35a is fixed to the flange portion of the hub wheel 34a. The brake rotor 35 a rotates integrally with the wheel 32. A friction type brake 35 is configured by the brake rotor 35a and the brake caliper 35b. The motor 36 is, for example, an embedded magnet synchronous motor in which a permanent magnet (not shown) is incorporated in the core portion of the rotor 36a. The motor 36 is a motor having a radial gap between a stator 36 b fixed to the housing 38 and a rotor 36 a attached to the rotational output shaft 39.

The motor 36 is provided with a resolver 6 as a sensor for detecting the rotation of the rotation output shaft 39, and is provided with a temperature sensor 11 and a sensor substrate 19. The temperature sensor 11 is a sensor that detects the temperature of the motor 36, for example, the temperature of the stator. In the case of a liquid-cooled motor 36, the temperature sensor 11 may detect the oil temperature, and a plurality of temperature sensors 11 are provided to perform temperature detection and oil temperature detection of the stator, respectively. It may be The sensor substrate 19 will be described later.

FIG. 2 is a basic structure of an in-wheel motor system. The inverter device 1 mounted on the vehicle body 51 of FIG. 1 and the motor 36 in the in-wheel motor drive device 10 are connected by the motor cable 14 of each phase, which is a power line for driving the motor. The resolver 6 and the temperature sensor 11 in the in-wheel motor drive device 10 are connected to the inverter device 1 by a sensor signal cable 13 for transmitting and receiving sensor drive power and signals. The sensor signal cable 13 is representatively shown by one in FIG.

<Outline of sensor signal / sensor power circuit>
FIG. 3 shows a circuit of sensor signals and sensor power in the in-wheel motor system of this embodiment. In order to explain the features of this embodiment, in order to reduce the wiring between the in-wheel motor drive device 10 and the inverter device 1 as compared with the prior art, the RD converter 2 or the temperature normally in the inverter device 1 on the vehicle body The sensor circuit 18 is transferred to the in-wheel motor drive 10. The information digitized on the circuit on the in-wheel motor drive 10 side is communicated to the inverter 1 on the vehicle side via the communication transmission line 16. Usually, two to three wires are required for digital communication, but in this embodiment, two wires are used. In addition to this, two are separately required for power supply, and the two power supply lines 15 are provided. Therefore, in this embodiment, the number of wires between the in-wheel motor drive device 10 and the inverter device 1 is four. The power supply line 15 and the communication transmission line 16 are represented as one sensor signal cable 13 in FIG. A sensor substrate 19 is installed in the in-wheel motor drive device 10, and an RD converter 2, a temperature sensor circuit 18, and a communication circuit 22 are commonly mounted on the same sensor substrate 19.

<Resolver 6>
The resolver 6 is composed of a resolver rotor 5 and a resolver stator 4, and the resolver stator 4 has a SIN coil 8, a COS coil 9 and an excitation coil 7 which have an electrical angle difference of 90 degrees. Either the SIN coil 8 or the COS coil 9 may be used for excitation, and the excitation coil 7 may be omitted.

<RD converter 2>
The RD converter 2 is a device for converting the detection signal of the resolver 6 into a digital signal, and outputs an excitation current from the excitation circuit 3 to the excitation coil 7 of the resolver 6, and the excitation coil 7 of the resolver 6, SIN coil 8 and A detection signal of the COS coil 9 is obtained from the reference signal (REF) input terminal, the SIN signal input terminal, and the COS signal input terminal, and is output from the output terminal as a digital signal.

<Temperature sensor circuit 18>
The temperature sensor circuit 18 is a circuit that converts an analog signal output from the temperature sensor 11 as a detection signal into a digital signal and outputs the digital signal.

<Communication circuit 22>
The communication circuit 22 converts rotational position signals and temperature detection signals obtained as digital signals from the RD converter 2 and the temperature sensor circuit 18 into serial signals (by time multiplexing in the case of a plurality of types of signals) to the communication transmission line 16. It is a means to output. The communication circuit 22 may be unbalanced communication means such as RS232C or Ethernet (registered trademark), or communication means such as RS485 or CAN differential circuit 22a as shown in FIG. 5, or 3-wire communication means. (Not shown) may be used. The communication direction may be bidirectional as shown in FIG. 4, or may be unidirectional from the in-wheel motor drive device 10 to the inverter device 1. The communication transmission line 16 may include a shielded electric wire shown in FIG. 3 that is grounded (on the GND side). In addition, for the communication, a communication method of differential input such as LVDS (Low Voltage Differential Signaling) may be used.

<Power supply>
In order to supply power to the RD converter 2 and the communication circuit 22, a power supply line 15 prepared separately from the communication transmission line 16 is used. The power supply line 15 is connected to a power supply 25 for a weak electric device provided separately from the motor drive of the inverter device 1. The power supply 25 is a DC power supply of about 5 to 24 V, and is set to, for example, 5 V, 12 V, or 24 V. The wiring on the positive side of the power supply line 15 is grounded via the power supply capacitor 17, and the wiring on the negative side is installed (GND side). The power supply capacitor 17 is provided in each of the inverter device 1 and the in-wheel motor drive device 10.

<Number of wires>
The number of electric wires between the inverter device 1 and the in-wheel motor drive device 10 will be three if the ground side (GND side) of the power supply line 15 and the communication transmission line 16 is common. The form is a total of four. If the three-wire communication means 22 is adopted, the number of electric wires increases by one.

<Communication content>
The contents of communication by the communication circuit 22 are mainly information on the rotational position of the motor 36 detected by the resolver 6 from the in-wheel motor drive device 10 side to the inverter device 1 side. Detection value is added. When the resolver 6 or the in-wheel motor drive device 10 has a detection function of resolver state, resolver signal abnormality, resolver initial diagnosis, or the RD converter 2 has RD converter temperature, RD converter self-diagnosis function, some are in-wheel When the motor drive device 10 has other sensors, these states, diagnosis results, sensor-related signals, etc. are added. In the case of two-way communication, there are communication contents from the inverter device 1 side to the in-wheel motor drive device 10 side, including, for example, a command for performing self-diagnosis and a command for performing abnormality reset.

<Sensor related configuration in inverter device 1>
The inverter device 1 includes a communication unit 22A in addition to the power supply 25 as a unit related to driving of the RD converter 2 and sensors and signal reception. The communication unit 22A is a unit that receives the rotational position and temperature signals and the like transmitted from the communication unit 22 of the in-wheel motor drive device 10 through the communication transmission line 16, and outputs the signals to the CPU 10. The CPU 30 is means for controlling the current sent from the motor cable 14 for driving the traveling motor 36 (see FIG. 2), and uses the signals of the rotational position and temperature for the control. In the case of bi-directional communication, the communication means 22A includes the transmission function from the inverter device 1 side to the in-wheel motor drive device 10 side as described above.

<Action, effect>
According to the in-wheel motor system of this configuration, since the RD converter 2, the temperature sensor circuit 18, and the communication circuit 22 are mounted on the in-wheel motor drive device 10, the detection signals of the resolver 6 and the temperature sensor 11 are analog as they are Unlike signal transmission, it can be digitized and transmitted by serial transmission. Therefore, transmission of signals between the in-wheel motor drive device 10 and the inverter device 1 can be performed with a small number of wires. Although two are shown in the illustrated example, water resistance, oil resistance, high temperature resistance, low temperature resistance, vibration resistance and bending resistance are required for the wiring between the in-wheel motor drive device 10 and the inverter device 1 Therefore, the reduction in the number of wires facilitates the realization of those performance requirements. It also facilitates connector design, manufacture and selection. Also, unlike the configuration in which the inverter device 1 is mounted on the in-wheel motor drive device 10, it is the RD converter 2, the temperature sensor circuit 18, and the communication circuit 22 that are mounted on the in-wheel motor drive device 10. Since the in-wheel motor drive 10 is large, it does not get stuck in the wheel.

Further, since the RD converter 2, the temperature sensor circuit 18, and the communication circuit 22 are provided on the common sensor substrate 19, the mounting of the wiring and various electronic elements can be made more compact.

Other Embodiments
FIG. 5 shows another embodiment of the present invention. This embodiment is the same as the embodiment described above with reference to FIGS. 1 to 4 except for items to be particularly described. In this embodiment, the signal communicated between the in-wheel motor drive device 10 and the inverter device 1 is superimposed on the power supply current, and the wire between the in-wheel motor drive device 10 and the inverter device 1 transmits two communication powers. It is only the line 24. The communication power transmission line 24 can be one if the shield line is not used. By thus reducing the number of wires, it is possible to further improve the wire cost and reliability. Specifically, by providing the signal superimposing means 28 in the in-wheel motor drive device 10, the sensor signal is superimposed on the current for power supply so that the power supply and communication of the signal can be performed by the communication power transmission line 24. ing. Further, the inverter device 1 is provided with signal separation means 29 for separating the signal superimposed on the current for power supply. Although signal transmission is performed between the signal superimposing means 28 and the signal separating means 29, the signal transmission may be unidirectional or bidirectional from one means to the other.

<Signal superposing means 28>
The signal superposition means 28 comprises modulation means 23 connected to the output terminal of the communication means 22 to modulate the signal. The signal superimposing means 28 has a coupling capacitor 20 interposed between the output terminal of the modulation means 23 and the plus side wiring of the communication power transmission line 24. Furthermore, the signal superimposing means 28 has a choke coil 21. The signal superimposing means 28 is mounted on the sensor substrate 19. The choke coil 21 is interposed between a connection point of the communication power transmission line 24 with the coupling capacitor 20 and a power input terminal of the communication unit 22. The modulation unit 23 includes a circuit such as a modulation functional element, modulates a signal so as not to include a DC component and a low frequency AC component, and performs impedance matching (matching). The communication and modulation methods may be arbitrary methods, for example, FM modulation, digital modulation, pulse modulation and the like.

<Signal separation means 29>
The signal separation means 29 has a coupling capacitor 20A connected to the plus side wiring of the communication power transmission line 24 in the inverter device 1. The signal separation means 29 has a demodulation means 23A connected to the communication power transmission line 24 via the coupling capacitor 20A and having a demodulation output terminal connected to the communication means 22. Furthermore, the signal separation means 29 has a choke coil 21A. The choke coil 21A is interposed between a connection point of the communication power transmission line 24 with the coupling capacitor 20A and a power input terminal of the communication means 22A.

<Supplementary Description of Operation of Other Embodiments and Description of Configuration>
The power supply from the power supply 25 is a direct current, and the transmission of the communication signal to be superimposed is, for example, an AC signal of at least 1 kHz or more, usually 1 MHz or more. The power supply voltage is about 5 to 24V, for example 12V, or 24V, or 5V. The power supply is via the choke coil 21A provided in the inverter device 1, the communication power transmission line 24, and the choke coil 21 provided in the in-wheel motor drive device 10 to communicate with the RD converter 2 or communication in the in-wheel motor drive device 10. It is supplied to the means 22. The

power supply capacitors

17, 17A are attached for the stabilization of the power supply. In the in-wheel motor drive device 10, the voltage can also be converted by a regulator, a DC-DC converter or the like (not shown) as necessary. The contents of communication are the same as in the previous embodiment.

The rotation detection position information of the resolver rotor 5 and the temperature information of the temperature sensor 11 pass through the communication means 22 of the in-wheel motor drive device 10, the modulation means 23 and the coupling capacitor 20, and pass through the communication power transmission line 24 It passes through the coupling capacitor 20A on the device 1 side, the demodulation means 23A, and the communication means 22A, and is transmitted to the CPU 30 of the inverter device 1. In the case of two-way communication, information is transmitted in the opposite direction.

In the case of this embodiment, since the signal of the information communication is superimposed on the wiring (communication power transmission line 24) for supplying power to the RD converter 2 and the like as described above, the number of wirings can be further reduced. The wiring is required to have water resistance, oil resistance, high temperature resistance, low temperature resistance, vibration resistance, and bending resistance, but the reduction in the number of wirings facilitates the realization of the required performance. It also facilitates connector design, manufacture and selection.

Although each of the above embodiments is directed to an electric vehicle having two in-wheel motor systems, the present invention also applies to two or more sets of two in-wheel motor systems even in the case of an electric vehicle having four-wheel drive or more It can be applied as having. It can also be applied to electric vehicles having only one in-wheel motor system.

As described above, although the preferred embodiments have been described with reference to the drawings, various additions, modifications, and deletions can be made without departing from the spirit of the present invention. Therefore, such is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Inverter apparatus 2 ... RD converter 6 ... Resolver 10 ... In-wheel motor drive apparatus 11 ... Temperature sensor 13 ... Sensor signal cable 14 ... Motor cable 15 ... Power supply line 16 ...

Communication transmission line

17, 17A ... Power supply capacitor 18 ... Temperature Sensor circuit 19:

Sensor substrate

20, 20A: Coupling

capacitor

21, 21A:

Choke coil

22, 22A: Communication means
23 Modulation means 23A Demodulation means 24 Communication power transmission line 28 Signal superposition means
29: Signal separation means
32: Wheels 34: Wheel bearings 36: Motor 37: Reduction gear

Claims

An in-wheel motor system in which an in-wheel motor drive device having a motor and a bearing for a wheel, and an inverter device installed on a vehicle body for converting direct current power of a battery to alternating current power and controlling output are connected by wiring. ,
An RD converter for converting a detection signal of a resolver for detecting rotation of the motor into a digital signal, a temperature sensor circuit for processing a detection signal of a temperature sensor for detecting the temperature of the motor, an output of the RD converter and the temperature sensor The in-wheel motor system by which the communication circuit which transmits the output of a circuit is mounted in the said in-wheel motor drive device.
The in-wheel motor system according to claim 1, wherein the wiring includes a communication power transmission line for supplying the power supply power of the low-power system output from the inverter device to the in-wheel motor drive device. In-wheel motor system having signal superimposing means for superimposing the signal of the information communication on current flowing through the wire in the in-wheel motor drive device, and signal separating means for separating the signal superimposed on the current in the inverter device .
The in-wheel motor system according to claim 1 or 2, wherein the RD converter, the temperature sensor circuit, and the communication circuit are provided on a common sensor substrate.
An electric vehicle equipped with the in-wheel motor system according to any one of claims 1 to 3.