system

Abstract

This system provides a way to accurately determine the DC component of the current flowing through the field winding. [Solution] The system comprises a rotating electric machine. The rotating electric machine has a stator and a rotor 60 having field windings 70. The system comprises a field voltage sensor 90 provided on the rotor 60, a transmitter 101 provided on the rotor 60, a receiver 102 provided on the stator or a base member fixed to the stator, and a smoothing processing unit 100 provided on the rotor 60. The smoothing processing unit 100 performs a smoothing process to smooth the detection signal of the field voltage sensor 90 and inputs the smoothed detection signal to the transmitter 101. The transmitter 101 wirelessly transmits the detection signal smoothed by the smoothing processing unit 100 to the receiver 102.

Description

Technical Field

[0001] The present disclosure relates to a system including a rotating electric machine.

Background Art

[0002] Conventionally, as described in Patent Document 1, a system of a rotating electric machine including a stator having a stator winding and a rotor having a field winding is known. This system includes a signal coil provided on the rotor and a magnetic field sensor provided on the stator. An alternating current flowing through the field winding flows through the signal coil. The magnetic field generated as the alternating current flows through the signal coil intersects the magnetic field sensor. In this case, an alternating current having the same frequency as the alternating current flowing through the signal coil flows through the magnetic field sensor. The alternating current flowing through the magnetic field sensor is detected by a processing unit connected to the magnetic field sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The generated torque of the rotating electric machine is contributed by the direct current component of the current flowing through the field winding provided on the rotor. Therefore, a technique for appropriately grasping the direct current component is desired.

[0005] The main object of the present disclosure is to provide a system that can appropriately grasp the direct current component of the current flowing through the field winding.

Means for Solving the Problems

[0006] A first disclosure is in a system including a rotating electric machine, wherein the rotating electric machine includes a stator having a stator winding, and A rotor having field windings, It has, A sensor provided on the rotor for detecting a field current containing high-frequency components flowing through the field winding or a field voltage containing high-frequency components generated in the field winding, A transmitter provided on the rotor, A receiver provided on the stator or a base member fixed to the stator, which receives the transmission signal of the transmitter, The rotor is provided with a smoothing processing unit that performs a smoothing process to smooth the detection signal of the sensor and inputs the smoothed detection signal to the transmitter, Equipped with, The transmitter wirelessly transmits the detection signal, which has been smoothed by the smoothing processing unit, to the receiver.

[0007] The detection signal for field current or field voltage contains high-frequency components. Therefore, even if the instantaneous value of the detection signal for field current or field voltage is transmitted from the transmitter to the receiver, the instantaneous value of the signal received by the receiver may not accurately represent the DC component of the field current or field voltage.

[0008] Here, the detection signal smoothed by the smoothing processing unit is a signal representing the DC component of the field current or field voltage. When the smoothed detection signal is transmitted from the transmitter to the receiver, the instantaneous value of the received signal at the receiver is a signal representing the DC component of the field current or field voltage. Based on the DC component of the field voltage, the DC component of the field current can be calculated.

[0009] According to the first disclosure, the DC component of the current flowing through the field winding can be properly determined in the configuration of the stator side or the base member side.

[0010] The second disclosure concerns a system equipped with a rotating electric machine, The aforementioned rotating electric machine is A stator having stator windings, A rotor having field windings, It has, An inverter connected to the stator winding, A sensor provided on the rotor for detecting a field current including a high-frequency component flowing through the field winding or a field voltage including a high-frequency component generated in the field winding, A transmitter provided on the rotor for wirelessly transmitting the detection signal of the sensor, A receiver provided on the stator or a base member fixed to the stator for receiving the transmission signal of the transmitter, A computer to which the reception signal of the receiver is input, Comprising, The computer has a smoothing processing unit that performs a smoothing process for smoothing the reception signal of the receiver, The computer performs switching control of the inverter based on the reception signal smoothed by the smoothing processing unit.

[0011] According to the second disclosure, in the configuration on the stator side or the base member side, the DC component of the current flowing through the field winding can be appropriately grasped.

Brief Description of Drawings

[0012] [Figure 1] Overall configuration diagram of the control system of the rotating electrical machine according to the first embodiment. [Figure 2] Diagram showing the inverter and its peripheral configuration. [Figure 3] Time chart showing the transition of the current flowing through the stator winding. [Figure 4] Diagram showing the electrical circuit of the rotor and the like. [Figure 5] Time chart showing the transition of the field voltage. [Figure 6] Time chart showing the transition of the field current. [Figure 7] Vertical sectional view of the rotating electrical machine in the first example. [Figure 8] Diagram of the rotor in the first example. [Figure 9] Vertical sectional view of the rotating electrical machine in the second example. [Figure 10]Diagram of the rotor in the second example. [Figure 11] Diagram showing an example of an analog low-pass filter circuit according to the second embodiment. [Figure 12] Diagram showing an example of an analog low-pass filter circuit. [Figure 13] Diagram showing an electric circuit such as a rotor according to the third embodiment. [Figure 14] Cross-sectional view of the rotor and stator according to the fourth embodiment. [Figure 15] Diagram showing an electric circuit such as a rotor. [Figure 16] Time chart showing the transition of the first and second field magnet voltages. [Figure 17] Time chart showing the transition of the first and second field magnet currents. [Figure 18] Diagram showing an electric circuit such as a rotor according to a modification of the fourth embodiment. [Figure 19] Diagram showing an electric circuit such as a rotor according to the fifth embodiment. [Figure 20] Diagram showing an electric circuit such as a rotor according to a modification of the fifth embodiment. [Figure 21] Diagram showing an electric circuit such as a rotor according to other embodiments.

Mode for Carrying Out the Invention

[0013] While referring to the drawings, a plurality of embodiments will be described. In a plurality of embodiments, parts that are functionally and / or structurally corresponding and / or associated may be assigned the same reference numerals, or reference numerals that differ in the hundreds place or more. For corresponding parts and / or associated parts, the description of other embodiments can be referred to.

[0014] <First Embodiment> The following describes a first embodiment of a system incorporating a rotating electric machine according to this disclosure, with reference to the drawings. The rotating electric machine is used, for example, as a power source for propulsion in electric vehicles such as electric cars and hybrid cars. It is also used, for example, as a power source for flight in aircraft or as a power source for navigation in ships. It should be noted that the rotating electric machine is not limited to mobile devices such as electric vehicles, but can also be applied to stationary devices.

[0015] First, the system overview will be explained using Figure 1. The system comprises a DC power supply 10, an inverter 20, a control device 30, and a rotating electric machine 40. The rotating electric machine 40 is a self-excited wound-field synchronous machine. For example, the rotating electric machine 40, inverter 20, and control device 30 may be configured as an integrated electromechanical drive unit, or the rotating electric machine 40, inverter 20, and control device 30 may each be configured as separate components.

[0016] The rotating electric machine 40 comprises a housing 41 and a stator 50 and a rotor 60 housed within the housing 41. The rotating electric machine 40 in this embodiment is an inner rotor type rotating electric machine in which the rotor 60 is positioned radially inward of the stator 50.

[0017] The stator 50 comprises a stator core 51 and stator windings 52. The stator windings 52 are made of, for example, copper wire and include U, V, and W phase windings 52U, 52V, and 52W arranged at an electrical angle of 120° from each other.

[0018] The rotor 60 comprises a rotor core 61 and field windings 70. The field windings 70 are made of, for example, aluminum wire, copper wire, or CNTs (carbon nanotubes). The rotor core 61 is provided with a rotating shaft 63. The rotating shaft 63 is rotatably supported in the housing 41 by bearings 42 and 43.

[0019] As shown in Figure 2, the inverter 20 comprises a series connection of U, V, W phase upper arm switches Sup, SVp, SWp and U, V, W phase lower arm switches SUn, SVn, SWn. In each phase, the first ends of the U, V, W phase windings 52U, 52V, 52W are connected to the connection point between the upper arm switches Sup, SVp, SWp and the lower arm switches SUn, SVn, SWn. The second ends of the U, V, W phase windings 52U, 52V, 52W are connected at the neutral point. In other words, in this embodiment, the stator winding 52 is star-connected. However, the stator winding 52 may be delta-connected. In this embodiment, each switch Sup to SWn is an IGBT. A freewheeling diode is connected in antiparallel to each switch Sup to SWn. Note that each switch Sup to SWn may be, for example, an N-channel MOSFET.

[0020] The collectors, which are the high-potential terminals of the upper arm switches Sup, SVp, and SWp for each phase, are connected to the positive terminals of the DC power supply 10. The emitters, which are the low-potential terminals of the lower arm switches SUn, SVn, and SWn for each phase, are connected to the negative terminals of the DC power supply 10. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0021] The system includes a current sensor 21 and a rotation angle sensor 22. The current sensor 21 detects the current of at least two phases of the current flowing through each phase winding 52U, 52V, and 52W. The rotation angle sensor 22 is configured, for example, by a resolver, and detects the rotation angle (e.g., electrical angle) of the rotor 60. The detected values ​​of each sensor 21 and 22 are input to the control device 30.

[0022] The control device 30 is an electronic control unit (ECC) mainly composed of a microcontroller 31. The microcontroller 31 is equipped with a CPU (Central Processing Unit). The functions provided by the microcontroller 31 can be provided by software recorded in a physical memory device and the computer that executes it, by software only, by hardware only, or by a combination thereof. For example, if the microcontroller 31 is provided by electronic circuits which are hardware, it can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, the microcontroller 31 executes a program stored in a non-transitory tangible storage medium which serves as its own memory. The program includes a program for the control processing of the rotating electric machine 40. The method corresponding to the program is executed by executing a set of instructions which constitute the program. The memory is, for example, non-volatile memory. The program stored in the memory can be updated via a communication network such as the Internet, for example, OTA (Over The Air).

[0023] The control device 30 generates drive signals to turn on and off each switch Sup to SWn that make up the inverter 20. Specifically, the control device 30 generates drive signals to turn on and off each switch Sup to SWn in order to convert the DC power output from the DC power supply 10 into AC power and supply it to the U, V, and W phase windings 52U, 52V, and 52W, and outputs the generated drive signals to the gates of each switch Sup to SWn. As a result, the upper arm switch and the lower arm switch are turned on alternately in each phase, with a dead time in between.

[0024] As shown in Figure 3, the control device 30 switches Sup~SWn on and off to supply a combined current to each phase winding 52U, 52V, and 52W, consisting of a fundamental wave current corresponding to the commanded torque of the rotating electric machine 40 and a high-frequency current (specifically, a high-frequency excitation current) with a frequency higher than that of the fundamental wave current. The fundamental wave current is primarily used to generate torque in the rotating electric machine 40. The high-frequency excitation current is primarily used to excite the field winding 70 and induce a field current in the field winding 70. The phase currents flowing through each phase winding 52U, 52V, and 52W are shifted by 120° in electrical angle.

[0025] The high-frequency excitation current flowing through the stator winding 52 may be a harmonic current whose fluctuation frequency is N times the frequency of the fundamental wave current (where N is an integer greater than or equal to 2), or it may be a current whose fluctuation frequency is outside of N times the frequency of the fundamental wave current.

[0026] When a high-frequency excitation current flows through the stator winding 52, which functions as an excitation coil, a field voltage is induced in the field winding 70, causing a field current to flow. The field current flowing through the field winding 70 includes a component that fluctuates with the frequency fsh (=1 / Tsh) of the high-frequency excitation current. In Figure 3(b), Tsh represents the period of the high-frequency excitation current. The frequency fsw of the high-frequency excitation current is set to a frequency that allows for, for example, the energization control (specifically, switching control) of the inverter 20, and is set to a few kHz.

[0027] Next, we will explain the system's electrical circuit using Figure 4.

[0028] The rotor 60 is equipped with a diode 80. The diode 80 connects the first and second ends of the field winding 70. The diode 80 rectifies the field current flowing through the field winding 70.

[0029] The rotor 60 is equipped with a field voltage sensor 90 that detects the field voltage, which is the voltage between the terminals of the field winding 70. The system has a characteristic configuration for transmitting the detected field voltage information to the microcontroller 31. Specifically, the rotor 60 is equipped with a smoothing processing unit 100 and a transmitter 101. The stator 50 is equipped with a receiver 102 that receives the transmission signal from the transmitter 101. The receiver 102 is connected to the microcontroller 31. Various communication devices, such as analog wireless communication devices or digital wireless communication devices, can be used as the transmitter 101 and the receiver 102. In addition, the receiver 102 may be provided in a housing 41 (corresponding to the "base member") fixed to the stator 50 instead of the stator 50.

[0030] The detection signal from the field voltage sensor 90 is input to the smoothing processing unit 100. The smoothing processing unit 100 performs a smoothing process to smooth the detection signal from the field voltage sensor 90 and inputs the smoothed detection signal to the transmitter 101. The smoothing process in this embodiment is a process of calculating the time average value of the detection signal from the field voltage sensor 90 over a specified period of length Tsh or longer than the period of the high-frequency excitation current. By setting the time averaging period to the specified period, the detection signal from the field voltage sensor 90, which pulsates with the same period as the high-frequency excitation current, can be effectively averaged, and consequently, the DC component of the detection signal can be extracted.

[0031] In this embodiment, the specified period is set to a period that is N times the period Tsh of the high-frequency excitation current (where N is an integer of 1 or more). This allows for accurate extraction of the DC component from the detection signal of the field voltage sensor 90, which pulsates with the same period as the period Tsh of the high-frequency excitation current. Preferably, the specified period is set to a period shorter than the period T (=1 / f) corresponding to the response frequency f of the vehicle or machine driven by the rotating electric machine 40 (for example, a period of 50 msec or less). This ensures good controllability of the vehicle or machine by the rotating electric machine 40.

[0032] The reason for smoothing the detection signal will be explained. The DC component of the field current contributes to the torque generated by the rotating electric machine 40. Therefore, it is important to understand this DC component in order to control the torque generated by the rotating electric machine 40 to the commanded torque.

[0033] On the other hand, as shown in Figures 5 and 6, the field voltage and field current of the field winding 70 include the frequency component of the high-frequency excitation current. Therefore, if only the instantaneous values ​​of the field voltage and field current are transmitted to the microcontroller 31, the microcontroller 31 cannot accurately grasp the DC component of the field voltage and field current.

[0034] Here, the detection signal smoothed by the smoothing processing unit 100 is a signal representing the DC component of the field voltage. When the smoothed detection signal is transmitted from the transmitter 101 to the receiver 102, the instantaneous value of the received signal at the receiver 102 is a signal representing the DC component of the field voltage. The microcontroller 31 can calculate the DC component of the field current based on the DC component of the field voltage. This allows the microcontroller 31 to determine the DC component of the field current used for torque control.

[0035] The receiver 102 receives information on the DC component transmitted from the transmitter 101. The received signal from the receiver 102 is input to the microcontroller 31. Based on the input information on the DC component of the field voltage, the microcontroller 31 calculates the time-averaged value of the field current as the DC component of the field current. More specifically, the microcontroller 31 calculates the time-averaged value of the field current by dividing the DC component of the field voltage by the resistance value of the field winding 70. Based on the calculated time-averaged value of the field current, the microcontroller 31 performs switching control of the inverter 20 in order to control the torque generated by the rotating electric machine 40 to the commanded torque.

[0036] Furthermore, the microcontroller 31 may, for example, perform temperature estimation processing for the rotor 60 or abnormality diagnosis processing for the electrical components constituting the rotor 60 based on the time average value of the calculated field current.

[0037] Next, we will describe an example of the arrangement of the transmitter 101 and receiver 102 in the rotating electric machine 40.

[0038] <<First example>> The first example will be explained using Figures 7 and 8. In the following description, the direction in which the rotation axis 63 extends is referred to as the axial direction, the direction radiating from the center of the rotation axis 63 is referred to as the radial direction, and the direction circumferentially extending around the rotation axis 63 is referred to as the circumferential direction.

[0039] In Figure 7, Lα indicates the rotational axis of the rotor 60 extending in the axial direction. Also, in Figures 7 and 8, the structure of the field winding 70 and other components is simplified for convenience.

[0040] The housing 41 comprises a cylindrical outer cylinder portion 44 and a cover portion 45 that closes one of a pair of openings in the axial direction of the outer cylinder portion 44. Figure 8 is a view of the rotor 60 of Figure 7 from the cover portion 45 side.

[0041] In this embodiment, the transmitter 101 is provided at the end of the rotor core 61 that constitutes the rotor 60, in the axial direction, that faces the cover portion 45. The receiver 102 is provided at the end of the rotor core 61 in the axial direction of the cover portion 45. The transmitter 101 and the receiver 102 are arranged, for example, on concentric circles centered on the rotational axis Lα.

[0042] In the first example, the transmitter 101 and receiver 102 face each other axially only when the rotational position of the rotor 60 reaches a specific rotational position during one revolution of the rotor 60. In this facing state, the transmitter 101 can transmit a signal to the receiver 102. Here, the signal input from the smoothing processing unit 100 to the transmitter 101 is a signal of the DC component of the field voltage. Therefore, even in a configuration where signal transmission is only possible when the rotational position of the rotor 60 reaches a specific rotational position during one revolution of the rotor 60, the signal of the DC component of the field voltage can be accurately transmitted to the microcontroller 31. Incidentally, the transmitter 101 may be provided in multiples arranged circumferentially at the ends of the rotor core 61. For example, the transmitters 101 may be arranged at equal intervals circumferentially, in the same number as the number of pole pairs of the rotor 60. As a result, information of the DC component of the field voltage is input to the microcontroller 31 every 360 degrees of electrical angle.

[0043] <<Second example>> The second example will be explained using Figures 9 and 10.

[0044] The transmitter 101 is located at the end of the rotor 60 (specifically, the rotating shaft 63) that is on the side of the cover 45. More specifically, this end is provided with an annular portion 222 that forms a ring shape centered on the rotational axis Lα. The transmitter 101 is located on the outer circumference of the annular portion 222. The receiver 102 is located on the cover 45 at a position opposite the transmitter 101 in the axial direction.

[0045] In the second example, the transmitter 101 and receiver 102 face each other in the axial direction, regardless of the rotational position of the rotor 60. Therefore, a signal can be transmitted from the transmitter 101 to the receiver 102 regardless of the rotational position of the rotor 60. Consequently, for example, a signal can be transmitted even when the rotor 60 is stopped rotating.

[0046] <Second Embodiment> The second embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. The smoothing processing unit 100 of this embodiment performs low-pass filtering as a smoothing process. The smoothing processing unit 100 is configured such that the cutoff frequency fcut of the low-pass filtering is lower than the frequency fsh of the high-frequency excitation current. This removes frequency components that pulsate at the same frequency as the frequency fsh of the high-frequency excitation current from the detection signal of the field voltage sensor 90, and extracts the DC component from the detection signal.

[0047] The low-pass filter processing of the smoothing processing unit 100 may be digital or analog. In the case of analog processing, the smoothing processing unit 100 may be an RC circuit as shown in Figure 11, or an LC circuit as shown in Figure 12. The RC circuit in Figure 11 comprises a resistor 111 and a capacitor 112. The LC circuit in Figure 12 comprises a reactor 121 and a capacitor 122.

[0048] <Third Embodiment> The second embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 13, the rotor 60 is equipped with a field current sensor 91 that detects the field current flowing through the field winding 70, instead of a field voltage sensor 90. The smoothing processing unit 100 performs a smoothing process to smooth the detection signal from the field current sensor 91. The receiver 102 receives information on the DC component of the field current transmitted from the transmitter 101. The received signal from the receiver 102 is input to the microcontroller 31. Based on the input information on the DC component of the field current, the microcontroller 31 performs, for example, switching control of the inverter 20.

[0049] According to the embodiment described above, the same effects as those of the first embodiment can be achieved.

[0050] <Fourth Embodiment> The fourth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the configuration of the rotating electric machine 40 has been changed, as shown in Figure 14.

[0051] The stator core 51 is made of laminated steel plates made of soft magnetic material and has an annular back yoke 51a and a plurality of teeth 51b that protrude radially inward from the back yoke 51a. A plurality of slots 54 are formed between adjacent teeth 51b, arranged in the circumferential direction. The stator windings 52 are formed by housing the phase windings of each phase in a predetermined order in each of these slots 54. For example, a segment coil structure using a plurality of conductor segments may be adopted in the stator 50. However, the structure of the stator windings 52 is arbitrary.

[0052] The rotor core 61 is made of a soft magnetic material, for example, laminated steel plates. The rotor core 61 has a cylindrical portion 61a and a plurality of main pole portions 62 that extend radially outward from the cylindrical portion 61a. Field windings 70 are wound around the main pole portions 62 by concentrated winding. In this embodiment, eight main pole portions 62 are provided at equal intervals in the circumferential direction.

[0053] The field winding 70 comprises a first winding section 71 and a second winding section 72. The first winding section 71 is wound radially outward around each main pole section 62, and the second winding section 72 is wound radially inward from the first winding section 71. In each main pole section 62, the winding directions of the conductor material in the first winding section 71 and the second winding section 72 are the same. Furthermore, among circumferentially adjacent main pole sections 62, the winding directions of the winding sections 71 and 72 wound on one are opposite to those of the winding sections 71 and 72 wound on the other. As a result, the magnetization directions of circumferentially adjacent main pole sections 62 are opposite to each other. In the rotor 60, multiple magnetic poles (field poles) aligned in the circumferential direction are formed by each main pole section 62 in the rotor core 61 and the field winding 70 wound around each main pole section 62.

[0054] Next, we will explain the electrical circuit of the system using Figure 15.

[0055] In the rotor 60, the first winding section 71 and the second winding section 72 are connected in series. The rotor 60 includes a first diode 81a, a first capacitor 82a, a second diode 81b, and a second capacitor 82b. The first end of the first winding section 71 is connected to the first end of the first capacitor 82a and the cathode of the first diode 81a. The second end of the first winding section 71 and the first end of the second winding section 72 are connected to the first end of the second capacitor 82b and the cathode of the second diode 81b. The second end of the second winding section 72 is connected to the second end of the first capacitor 82a, the anode of the first diode 81a, the second end of the second capacitor 82b, and the anode of the second diode 81b. The field current flowing through the first winding section 71 and the second winding section 72 is rectified by the first diode 81a and the second diode 81b. The first capacitor 82a and the second capacitor 82b are, for example, ceramic capacitors or film capacitors.

[0056] The rotor 60 includes a first field voltage sensor 90a that detects the first field voltage, which is the terminal voltage of the first winding section 71, and a second field voltage sensor 90b that detects the second field voltage, which is the terminal voltage of the second winding section 72.

[0057] The system includes a first smoothing processing unit 100a, a second smoothing processing unit 100b, and a transmitter 101 as components on the rotor 60 side for transmitting information on the detected first and second field voltages to the microcontroller 31.

[0058] The first smoothing processing unit 100a performs a smoothing process on the detection signal of the first field voltage sensor 90a in the same manner as the smoothing processing unit 100 of the first embodiment, and inputs the smoothed detection signal to the transmitter 101. The second smoothing processing unit 100b performs a smoothing process on the detection signal of the second field voltage sensor 90b in the same manner as the smoothing processing unit 100 of the first embodiment, and inputs the smoothed detection signal to the transmitter 101.

[0059] Receiver 102 receives information on the DC components of the first and second field voltages transmitted from transmitter 101. The received signal from receiver 102 is input to microcontroller 31. Based on the input information on the DC component of the first field voltage, microcontroller 31 calculates the time average value of the first field current flowing through the first winding section 71. Specifically, microcontroller 31 calculates the time average value of the first field current as the DC component of the first field current by dividing the DC component of the first field voltage by the resistance value of the first winding section 71. Furthermore, based on the input information on the DC component of the second field voltage, microcontroller 31 calculates the time average value of the second field current flowing through the second winding section 72 as the DC component of the second field current. Specifically, microcontroller 31 calculates the time average value of the second field current by dividing the DC component of the second field voltage by the resistance value of the second winding section 72.

[0060] Figure 16 shows the transitions of the first field voltage Ve of the first winding section 71 and the second field voltage Vm of the second winding section 72, and Figure 17 shows the transitions of the first field current Ie of the first winding section 71 and the second field current Im of the second winding section 72. Thus, even if the configuration of the field winding 70 differs from that of the first embodiment, the field currents of each winding section 71 and 72 are AC signals. For this reason, the same effects as in the first embodiment can be achieved by using the first smoothing processing unit 100a, the second smoothing processing unit 100b, the transmitter 101, and the receiver 102 of this embodiment.

[0061] <Modified form of the fourth embodiment> As shown in Figure 18, the rotor 60 may be equipped with a first field current sensor 91a for detecting the first field current flowing through the first winding section 71 and a second field current sensor 91b for detecting the second field current flowing through the second winding section 72, instead of the first and second field voltage sensors 90a and 90b. In this case, the first smoothing processing unit 100a performs a smoothing process to smooth the detection signal of the first field current sensor 91a, and the second smoothing processing unit 100b performs a smoothing process to smooth the detection signal of the second field current sensor 91b. The receiver 102 receives information on the DC components of the first and second field currents transmitted from the transmitter 101. The received signal from the receiver 102 is input to the microcontroller 31.

[0062] <Fifth Embodiment> The fifth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 19, the smoothing process is performed on the stator 50 side, rather than on the rotor 60. The detection signal from the field voltage sensor 90 is input to the transmitter 101.

[0063] The microcontroller 31 includes an A / D converter 31a, a smoothing processing unit 31b, and a control processing unit 31c. The received signal from the receiver 102 is input to the A / D converter 31a. The A / D converter 31a converts the input analog signal into a digital signal and inputs it to the smoothing processing unit 31b.

[0064] The smoothing processing unit 31b performs a smoothing process to smooth the input signal in the same manner as the smoothing processing unit 100 in the first embodiment. This process extracts the DC component of the field voltage. The extracted DC component is input to the control processing unit 31c. Based on the DC component of the input field voltage, the control processing unit 31c calculates the time-averaged value of the field current in the same manner as in the first embodiment.

[0065] <Modified form of the fifth embodiment> As shown in Figure 20, the rotor 60 may be equipped with the first field voltage sensor 90a and the second field voltage sensor 90b described in the fourth embodiment. Alternatively, the rotor 60 may be equipped with the first field current sensor 91a and the second field current sensor 91b shown in Figure 18 instead of the first field voltage sensor 90a and the second field voltage sensor 90b.

[0066] <Other Embodiments> Furthermore, each of the above embodiments may be implemented with the following modifications.

[0067] As shown in Figure 21, the rotor 60 may be equipped with a temperature sensor 92 for detecting the temperature of the field winding 70. The temperature detection signal from the temperature sensor 92 is input to the transmitter 101. The transmitter 101 transmits the temperature detection signal to the receiver 102. The temperature detection signal received by the receiver 102 is input to the microcontroller 31. Based on the input temperature detection signal, the microcontroller 31 may determine that an overheating abnormality of the rotor 60 has occurred if it determines that the temperature of the field winding 70 has exceeded the threshold temperature Tth. The microcontroller 31 may also perform switching control of the inverter 20 to adjust the amplitude of the high-frequency excitation current flowing to the stator winding 52 based on the input temperature detection signal.

[0068] The rotor 60 may include both a field voltage sensor 90 and a field current sensor 91. The detection signals from the field voltage sensor 90 and the field current sensor 91 are smoothed by the smoothing processing unit 100 and then input from the transmitter 101 to the microcontroller 31 via the receiver 102. In this case, the microcontroller 31 may, for example, estimate the temperature of the field winding 70 used to determine whether or not there is an overheating abnormality based on the smoothed detection signals from the field voltage sensor 90 and the field current sensor 91.

[0069] The rotating electric machine may be a separately excited wound-field type synchronous machine. This rotating electric machine includes, for example, a rotary transformer having an excitation coil provided on the stator and a power receiving coil provided on the rotor.

[0070] The rotating electric machine is not limited to an inner rotor type; an outer rotor type may also be used. In this case, the main pole portion protrudes radially inward from the rotor core.

[0071] The stator core may be one without teeth.

[0072] The rotating electric machine may be an axial gap type, rather than a radial gap type.

[0073] The control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control unit and its method described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium.

[0074] The following describes the characteristic configurations extracted from each of the embodiments described above. [Configuration 1] In a system equipped with a rotating electric machine (40), The aforementioned rotating electric machine is A stator (50) having stator windings (52), A rotor (60) having field windings (70), It has, Sensors (90, 91, 90a, 90b, 91a, 91b) provided on the rotor for detecting field current containing high-frequency components flowing through the field winding or field voltage containing high-frequency components generated in the field winding, A transmitter (101) is provided on the rotor, A receiver (102) is provided on the stator or a base member (41) fixed to the stator, and receives the transmission signal of the transmitter. The rotor is provided with a smoothing processing unit (100, 100a, 100b) that performs a smoothing process to smooth the detection signal of the sensor and inputs the smoothed detection signal to the transmitter, Equipped with, The system includes a transmitter that wirelessly transmits the detection signal, which has been smoothed by the smoothing processing unit, to the receiver. [Configuration 2] In a system equipped with a rotating electric machine (40), The aforementioned rotating electric machine is A stator (50) having stator windings (52), A rotor (60) having field windings (70), It has, An inverter (20) connected to the stator winding, Sensors (90, 91, 90a, 90b, 91a, 91b) provided on the rotor for detecting field current containing high-frequency components flowing through the field winding or field voltage containing high-frequency components generated in the field winding, A transmitter (101) is provided on the rotor and wirelessly transmits the detection signal of the sensor, A receiver (102) is provided on the stator or a base member (41) fixed to the stator, and receives the transmission signal of the transmitter. A computer (31) to which the received signal from the receiver is input, Equipped with, The computer has a smoothing processing unit (31b) that performs a smoothing process to smooth the received signal of the receiver, The computer is a system that controls the switching of the inverter based on the received signal smoothed by the smoothing processing unit. [Configuration 3] The system according to configuration 1 or 2, wherein the smoothing processing unit performs a process to calculate the time average value of the detection signal of the sensor over a specified period having a length greater than or equal to the period of the high-frequency component included in the field current, as the smoothing process. [Structure 4] The system according to configuration 3, wherein when N is an integer of 1 or more, the smoothing processing unit sets the period of the high-frequency component to N times the period of the high-frequency component as the specified period in the smoothing process. [Composition 5] The smoothing processing unit performs low-pass filtering as the smoothing process, The system according to configuration 1 or 2, wherein the cutoff frequency of the low-pass filter processing is lower than the frequency of the high-frequency component included in the field current. [Composition 6] An inverter (20) connected to the stator winding, Computer (31) and, Equipped with, The system according to any one of configurations 1 to 5, wherein the computer controls the switching of the inverter to flow a high-frequency current, which is a current for inducing the field current in the field winding and which fluctuates at the frequency of the high-frequency component, through the stator winding. [Explanation of Symbols]

[0075] 40...Rotating electric machine, 41...Housing, 50...Stator, 52...Stator winding, 60...Rotor, 70...Field winding, 100...Smoothing unit, 101...Transmitter, 102...Receiver.

Claims

1. In a system equipped with a rotating electric machine (40), The aforementioned rotating electric machine is A stator (50) having stator windings (52), A rotor (60) having a field winding (70), It has, Sensors (90, 91, 90a, 90b, 91a, 91b) provided on the rotor for detecting field current containing high-frequency components flowing through the field winding or field voltage containing high-frequency components generated in the field winding, A transmitter (101) is provided on the rotor, A receiver (102) is provided on the stator or a base member (41) fixed to the stator, and receives the transmission signal of the transmitter. The rotor is provided with a smoothing processing unit (100, 100a, 100b) that performs a smoothing process to smooth the detection signal of the sensor and inputs the smoothed detection signal to the transmitter, Equipped with, The system includes a transmitter that wirelessly transmits the detection signal, which has been smoothed by the smoothing processing unit, to the receiver.

2. In a system equipped with a rotating electric machine (40), The aforementioned rotating electric machine is A stator (50) having stator windings (52), A rotor (60) having a field winding (70), It has, An inverter (20) connected to the stator winding, Sensors (90, 91, 90a, 90b, 91a, 91b) provided on the rotor for detecting field current containing high-frequency components flowing through the field winding or field voltage containing high-frequency components generated in the field winding, A transmitter (101) is provided on the rotor and wirelessly transmits the detection signal of the sensor, A receiver (102) is provided on the stator or a base member (41) fixed to the stator, and receives the transmission signal of the transmitter. A computer (31) to which the received signal from the receiver is input, Equipped with, The computer has a smoothing processing unit (31b) that performs a smoothing process to smooth the received signal of the receiver, The computer is a system that controls the switching of the inverter based on the received signal smoothed by the smoothing processing unit.

3. The system according to claim 1 or 2, wherein the smoothing processing unit performs a process to calculate the time average value of the detection signal of the sensor over a specified period having a length greater than or equal to the period of the high-frequency component included in the field current, as the smoothing process.

4. The system according to claim 3, wherein when N is an integer of 1 or more, the smoothing processing unit sets the period of the high-frequency component to N times the period of the high-frequency component as the specified period in the smoothing process.

5. The smoothing processing unit performs low-pass filtering as the smoothing process, The system according to claim 1 or 2, wherein the cutoff frequency of the low-pass filter processing is lower than the frequency of the high-frequency component included in the field current.

6. An inverter (20) connected to the stator winding, Computer (31) and, Equipped with, The system according to claim 1 or 2, wherein the computer controls the switching of the inverter to flow a high-frequency current, which is a current for inducing the field current in the field winding and which fluctuates at the frequency of the high-frequency component, into the stator winding.

Images