JP6180601B1 - Rotating electric machine for vehicles - Google Patents

Abstract

An object of the present invention is to suppress the temperature rise of a permanent magnet during a three-phase short circuit. When a control device 30 detects that an abnormal voltage detection unit 405 has a voltage value of an input / output terminal equal to or higher than a threshold voltage, the rotation speed detected by the rotation speed detection unit 10 is preset. When it is larger than the threshold value, the negative side arm short-circuit unit 406 simultaneously performs the multi-phase short circuit of the first multi-phase winding 301 and the multi-phase short circuit of the second multi-phase winding 302, while the detected rotational speed is When the value is equal to or lower than the threshold value, the second multiphase winding 302 is short-circuited after the first multiphase winding 301 is short-circuited by the negative-side arm short-circuit unit 406. [Selection] Figure 4

Description

  The present invention relates to a vehicular rotating electrical machine.

  Conventionally, a rotating electrical machine for a vehicle using a Landel type rotor has been used for a vehicle such as an automobile. The Landel-type rotor is provided with a plurality of claw-shaped magnetic pole portions in the circumferential direction. A permanent magnet is disposed between adjacent claw-shaped magnetic pole portions.

  Due to environmental problems in recent years, the load of electrical components mounted on the vehicle has increased rapidly, and an increase in the amount of power generated by a rotating electrical machine for vehicles has been demanded. In order to solve such a problem, a vehicular rotating electrical machine including a cooling fan that generates cooling air by rotating integrally with a rotor has been proposed (see, for example, Patent Document 1).

  In the conventional vehicular rotating electrical machine described in Patent Document 1, the stator has two sets of three-phase stator windings. The two sets of three-phase stator windings are referred to as the first three-phase stator windings x1, y1, and z1, and the second three-phase stator windings x2, y2, and z2, respectively. The three-phase stator windings x2, y2, and z2 are wound around the first three-phase stator windings x1, x2, and y2 with an electrical angle shifted by π / 6 radians.

  In the conventional vehicular rotating electrical machine described in Patent Document 1, harmonic components included in the induced power are canceled by providing two sets of three-phase stator windings having a π / 6 phase difference in electrical angle. be able to. Thereby, electrical noise and magnetic noise are reduced. Moreover, since a magnetic storm can be suppressed, the temperature rise of the claw-shaped magnetic pole part and the permanent magnet due to the magnetic storm can be suppressed.

JP-A-9-154266

  As described above, the conventional rotating electrical machine for a vehicle described in Patent Document 1 can suppress the temperature rise of the claw-shaped magnetic pole part and the permanent magnet due to a magnetic storm, but suppresses the temperature rise of the permanent magnet due to a multiphase short circuit. There is no intention to do that.

  In general, in a vehicular rotating electrical machine that converts DC power and AC power, when the B terminal voltage is an overvoltage, the negative arm is short-circuited to enable stable power supply. However, current flows through the coil of the rotating electrical machine due to the counter electromotive force at the time of the short circuit, and the magnetic pole of the stator is magnetized. When the permanent magnet of the electric motor passes through the vicinity of the magnetized magnetic pole, the magnetic field penetrating the permanent magnet increases and decreases, and an eddy current is generated in the permanent magnet. The eddy current generates heat in the permanent magnet.

  In Patent Document 1, since there is no intention to suppress the temperature rise of the permanent magnet due to the eddy current at the time of the multiphase short circuit, there is a problem that the temperature of the permanent magnet is increased at the time of the multiphase short circuit.

  This invention is made in order to solve this subject, and it aims at obtaining the rotary electric machine for vehicles which can suppress the temperature rise of the permanent magnet at the time of a multiphase short circuit.

  The present invention is a rotating electrical machine for a vehicle that exchanges DC power and AC power, and includes a rotor core having a plurality of claw-shaped magnetic pole pieces provided on the outer periphery, and a rotor winding wound around the rotor core A rotor provided with a wire, a stator core disposed opposite to the outer periphery of the rotor core and having a plurality of slots formed on the inner periphery, and wound around the stator core inserted into the slot Between the adjacent claw-shaped magnetic pole pieces of the rotor core and the leakage magnetic flux between the adjacent claw-shaped magnetic pole pieces is reduced. A permanent magnet magnetized in the direction, two cooling fans provided on both sides of the rotor core, for cooling the rotor winding and the permanent magnet, a switching element for the positive arm, and a negative arm Switching elements, and A power conversion unit that converts between direct current and alternating current, a control device that performs on / off control of the switching element of the positive arm and the switching element of the negative arm, and detecting the rotational speed of the vehicular rotating electrical machine A first multiphase winding and a second multiphase winding, each of which is formed by independently winding two windings connected in a multiphase manner around the stator core. The control device includes an abnormal voltage detection unit that detects whether a voltage value of the input / output terminal is equal to or higher than a preset threshold voltage; and the abnormal voltage detection unit When detecting that the voltage value of the terminal is equal to or higher than the threshold voltage, the first multiphase winding and the switching element of the negative arm of the second multiphase winding are made conductive, so that the first Multiphase short circuit of the multiphase winding and the second multiphase A negative-side arm short-circuit unit that performs multi-phase short-circuiting of the wire, and when the control device detects that the voltage value of the input / output terminal is equal to or higher than the threshold voltage, When the rotation speed detected by the rotation speed detection unit is larger than a preset threshold, the negative-side arm short-circuit unit causes the multi-phase short circuit of the first multi-phase winding and the second multi-phase winding to When the rotational speed detected by the rotational speed detection unit is equal to or lower than a preset threshold value, the negative-phase arm short-circuit unit causes the first multi-phase winding to be short-circuited. This is a vehicular rotating electrical machine that performs a multi-phase short circuit of the second multi-phase winding after performing the above.

  According to the rotating electrical machine for a vehicle of the present invention, when the abnormal voltage detection unit detects that the voltage value of the input / output terminal is equal to or higher than the threshold value, the rotation speed detected by the rotation speed detection unit is When the threshold value is larger than a preset threshold value, the negative-phase arm short-circuit unit simultaneously performs the multi-phase short circuit of the first multi-phase winding and the multi-phase short circuit of the second multi-phase winding to detect the rotational speed. When the rotation speed detected by the part is equal to or lower than a preset threshold value, the second multi-phase winding is performed after performing the multi-phase short circuit of the first multi-phase winding by the negative arm short circuit part. Since the multiphase short circuit is performed, the temperature increase of the permanent magnet at the time of the multiphase short circuit can be suppressed in both the high rotational speed region and the low rotational speed region.

It is the longitudinal cross-sectional view which showed the structure of the rotary electric machine for vehicles which concerns on Embodiment 1 of this invention. It is the perspective view which showed the structure of the rotor core provided in the rotary electric machine for vehicles which concerns on Embodiment 1 of this invention. It is the circuit diagram which showed the structure of the power converter device provided in the rotary electric machine for vehicles which concerns on Embodiment 1 of this invention. It is the block diagram which showed the structure of the control apparatus provided in the rotary electric machine for vehicles which concerns on Embodiment 1 of this invention. It is explanatory drawing which showed the relationship between the rotational speed in the rotary electric machine for vehicles, and the temperature change of a permanent magnet with the graph.

Embodiment 1 FIG.
1 is a longitudinal sectional view showing a configuration of a vehicular rotating electrical machine (hereinafter referred to as a rotating electrical machine 100) according to Embodiment 1 of the present invention. As shown in FIG. 1, the rotating electrical machine according to Embodiment 1 is a controller-integrated rotating electrical machine. FIG. 2 is a perspective view showing the configuration of the rotor core 4 of the rotary electric machine 100 according to Embodiment 1 of the present invention.

  In FIG. 1, the rotating electrical machine 100 includes a stator core 3 and a rotor core 4. The stator core 3 is supported by the front bracket 1 and the rear bracket 2. The rotor core 4 is inserted into the inner space of the stator core 3.

  The rotor core 4 has a plurality of magnetic pole pieces (see 4a and 4b in FIG. 2). These magnetic pole pieces are opposed to the inner peripheral surface of the stator core 3 through a gap. A rotor winding 7 is wound around the rotor core 4 as a field winding.

  Further, stator windings 301 and 302 as armature windings are wound around the stator core 3. The coil pieces of the stator windings 301 and 302 are inserted into the slots of the stator core 3. The stator windings 301 and 302 are each composed of a three-phase winding. The stator windings 301 and 302 are connected in parallel.

  The stator core 3 and the stator windings 301 and 302 constitute the stator 5 of the rotating electrical machine 100. Further, the rotor core 4 and the rotor winding 7 constitute a rotor 13 of the rotating electrical machine 100.

  Further, the front bracket 1 and the rear bracket 2 are tightened in a direction approaching each other by a plurality of bolts 101, and the stator core 3 is firmly held.

  The rotor shaft 6 passes through the center of the rotor core 4. The rotor shaft 6 is rotatably supported by a front side bearing 61 supported by the front bracket 1 and a rear side bearing 62 supported by the rear bracket 2.

  A front cooling fan 51 is fixed to the front end face of the rotor core 4. A rear cooling fan 52 is fixed to the rear end face of the rotor core 4. The front-side cooling fan 51 and the rear-side cooling fan 52 rotate together with the rotor core 4 and allow air to flow from the outside of the front bracket 1 and the rear bracket 2 to cool the inside of the rotating electrical machine main body 102. Both the front side cooling fan 51 and the rear side cooling fan 52 are constituted by centrifugal fans. Hereinafter, when the front side cooling fan 51 and the rear side cooling fan 52 are collectively referred to, they are referred to as cooling fans 51 and 52.

  The rotor core 4 includes a permanent magnet 41. The permanent magnet 41 is disposed between the front cooling fan 51 and the rear cooling fan 52 in the axial direction.

  As shown in FIG. 2, the stator core 4 is provided with claw portions 4a and claw portions 4b alternately in the circumferential direction. The claw portion 4a and the claw portion 4b are constituted by claw-shaped magnetic pole pieces. The shape of the outer surface of the nail | claw part 4a and the nail | claw part 4b is trapezoid as FIG. 2 shows. The claw portion 4a has a circumferential width that is widest on the rear side and gradually narrows toward the front side. Further, the radial thickness of the claw portion 4a is thickest on the rear side and gradually decreases toward the front side. The claw portion 4 a includes a space 4 c between the claw portion 4 a and the stator core 4. The space 4c is a through hole extending in the axial direction. On the other hand, the circumferential width of the claw portion 4b is narrowest on the rear side and gradually increases toward the front side. The radial thickness of the claw portion 4b is the thinnest on the rear side and gradually increases toward the front side. The claw portion 4 b includes a space 4 d between the claw portion 4 b and the stator core 4. The space 4d is a through hole extending in the axial direction. Further, a permanent magnet 41 is provided between the adjacent claw portions 4a and claw portions 4b. The permanent magnet 41 is magnetized in a direction to reduce the leakage magnetic flux between the adjacent claw portions 4a and claw portions 4b.

  The wind generated by the front cooling fan 51 shown in FIG. 1 passes through the space 4 d of the claw portion 4 b of the rotor core 4 and cools the permanent magnet 41. Similarly, the wind generated by the rear cooling fan 52 passes through the space 4c of the claw portion 4a of the rotor core 4 and cools the permanent magnet 41.

  As shown in FIG. 1, a pulley 12 is fixed to the front side end of the rotor shaft 6. The pulley 12 is wound around a transmission belt (not shown) that interlocks with a rotating shaft of a vehicle engine (not shown). On the other hand, a pair of slip rings 8 are fixed to the peripheral surface of the rear side end portion of the rotor shaft 6. The pair of slip rings 8 is in sliding contact with the pair of brushes 9. The pair of brushes 9 are supported by the brush holder 90.

  A magnetic pole position detection sensor 10 is disposed between the rear end of the rotor shaft 6 and the rear bracket 2. The magnetic pole position detection sensor 10 is composed of a sync resolver. The magnetic pole position detection sensor 10 includes a sensor rotor 111 fixed to the rear side end of the rotor shaft 6, a sensor stator 112 fixed to the rear bracket 2 so as to face the sensor rotor 111, and a sensor stator. And a sensor winding 113 fixed to 112. The magnetic pole position detection sensor 10 detects the rotation speed of the rotating electrical machine 100 by detecting the rotation of the rotor shaft 6.

  The control circuit board 40 is housed in a resin board housing case 71. A control circuit constituting the control device 30 is formed on the control circuit board 40. The control circuit controls the switching operation of the power converter 21 described later. The substrate storage case 71 is fixed to the outer surface portion of the heat sink 23. The substrate storage case 71 stores the control circuit board 40.

  The power conversion device 20 is fixed to the outside of the rear bracket 2. The power converter 20 includes a terminal 22a and a power converter 21. The power conversion device 20 performs power conversion between the stator windings 301 and 302 and a battery (not shown). The power conversion device 20 includes six power conversion units 21 and operates as a six-phase inverter or a six-phase converter.

  FIG. 3 is a circuit diagram showing a circuit configuration of power conversion device 20 provided in rotary electric machine 100 according to Embodiment 1 of the present invention. As shown in FIG. 3, in the first embodiment, six power conversion units 21 as vehicle power converters are provided.

  In each power conversion unit 21, two semiconductor switching elements 223, 224, 225, and 226 are connected in series. Specifically, semiconductor switching elements 224a, 224b, and 224c are connected in series to the semiconductor switching elements 223a, 223b, and 223c, respectively. Furthermore, semiconductor switching elements 226a, 226b, and 226c are connected in series to the semiconductor switching elements 225a, 225b, and 225c, respectively. Each semiconductor switching element 223, 224, 225, 226 is connected in reverse parallel to one diode. In each power conversion unit 21, these two semiconductor switching elements and two diodes are sealed in a resin to constitute a power module as one package.

  In each power conversion unit 21, one semiconductor switching element 223, 225 provided on the upper side and a diode antiparallel to the semiconductor switching element form a positive arm for one phase of the six-phase bridge circuit. It is composed.

  In each power conversion unit 21, one semiconductor switching element 224, 226 provided on the lower side and a diode antiparallel to the semiconductor switching element are connected to the negative-side arm for one phase of the six-phase bridge circuit. Is configured.

A series connection point of two semiconductor switching elements connected in series in each power conversion unit 21 is a one-phase stator of six-phase (U, V, W, X, Y, Z) stator windings. Each of the windings 301 and 302 is connected.
Specifically, the series connection point of the semiconductor switching elements 223 a and 224 a is connected to the U phase of the stator winding 301. A series connection point of the semiconductor switching elements 223 b and 224 b is connected to the V phase of the stator winding 301. A series connection point of the semiconductor switching elements 223 c and 224 c is connected to the W phase of the stator winding 301.
Similarly, the series connection point of the semiconductor switching elements 225 a and 226 a is connected to the Z phase of the stator winding 302. A series connection point of the semiconductor switching elements 225 b and 226 b is connected to the Y phase of the stator winding 302. A series connection point of the semiconductor switching elements 225 c and 226 c is connected to the X phase of the stator winding 302.

  Each of the six power converters 21 configured as described above is connected to a terminal 22a connected to a B terminal 24 for positive power input from a battery (not shown).

  The power conversion device 20 is connected to the control device 30 and includes a motor generator unit and a terminal 22a. The control device 30 performs on / off control of the semiconductor switching element of the power conversion unit 21. The rotating electrical machine main body 102 includes a first stator winding 301 having U, V, and W phase terminals, a second stator winding 302 having X, Y, and Z phase terminals, and a rotor winding 7. Is made up of.

  The motor generator section is composed of a portion surrounded by a one-dot chain line in FIG. That is, as shown in FIG. 3, the motor generator unit includes a field switching element 22, a free wheel diode 222, first three-phase upper arm switching elements 223 a to 223 c, and first three-phase lower arm switching elements. 224a to 224c, second three-phase upper arm switching elements 225a to 225c, and second three-phase lower arm switching elements 226a to 227c. The field switching element 22 constitutes a field circuit and performs energization control of the field current flowing through the rotor winding 7 by PWM control. The freewheel diode 222 is connected in series to the field switching element 22.

  The first three-phase upper arm switching elements 223a to 223c and the first three-phase lower arm switching elements 224a to 224c have a built-in parasitic diode, and a bridge rectifier circuit for controlling energization of the armature winding. It is composed. Further, a positive power input B terminal 24 from a battery is connected to the first three-phase upper arm switching elements 223a to 223c. The first three-phase lower arm switching elements 224a to 224c are connected to a GND terminal which is a ground input from the battery.

  Similarly, the second three-phase upper arm switching elements 225a to 225c and the second three-phase lower arm switching elements 226a to 226c have a built-in parasitic diode, and a bridge for controlling energization of the armature winding. A rectifier circuit is configured. Further, a positive power source input B terminal 24 from a battery is connected to the second three-phase upper arm switching elements 225a to 225c. The second three-phase lower arm switching elements 226a to 226c are connected to a GND terminal which is a ground input from the battery.

  In FIG. 3, the rotating electrical machine main body 102 is described as a three-phase field winding generator motor including the stator windings 301 and 302 and the rotor winding 7. Since it is not limited to three phases, the number of phases may be other than three phases. Furthermore, in Embodiment 1, it has been described that the power conversion device 20 and the rotary electric machine main body 102 are integrated in the rotary electric machine 100, but the power conversion device 20 and the rotary electric machine main body 102 are physically divided. It does not matter.

  Next, the internal configuration of the control device 30 will be described. FIG. 4 is a block diagram showing the internal configuration of the control device 30. As shown in FIG. 4, the control device 30 includes a B terminal voltage detection unit 401, a field current detection unit 402, a microcomputer 403, and a gate driver 404. The microcomputer 403 includes an abnormal voltage detection unit 405, a negative arm short circuit unit 406, and a field current control unit 407.

The control device 30 has various functions of the vehicle power converter other than those shown in FIG. 4, but only the portions related to the present invention are shown in FIG.
Similarly, the microcomputer 403 has various functions of the vehicular power converter other than those shown in FIG. 4, but only the portion related to the present invention is shown in FIG. 4 here.
The microcomputer 403 normally includes the first three-phase upper arm switching elements 223a to 223c, the first three-phase lower arm switching elements 224a to 224c, and the second three-phase upper arm switching element 225a by PWM control. ˜225c and the second three-phase lower arm switching elements 226a˜226c are provided with a PWM control unit that outputs a gate signal for turning on / off, FIG. 4 also illustrates the PWM control unit. Is omitted. The power conversion device 20 converts the DC power obtained from the battery into AC power by turning on and off the switching elements 223, 224, 225, and 226, and also converts the AC power obtained from the rotating electrical machine body 102 into DC power. Convert to electricity.

  The B terminal voltage detection unit 401 detects the voltage VB (B terminal voltage) of the B terminal 24 of the rotating electrical machine 100 using the potential of the negative terminal GND of the power conversion device 20 as a reference, and the detected voltage VB of the microcomputer 403 is detected. The signal is converted into the AD input range and input to the microcomputer 403 as the signal Vbsig.

  The field current detection unit 402 detects the current flowing through the rotor winding 7 with a current sensor, converts the detected current value into the AD input range of the microcomputer 403, and inputs it to the microcomputer 403 as a signal Ifsig. .

  The abnormal voltage detection unit 405 of the microcomputer 403 receives the signal Vbsig from the B terminal voltage detection unit 401. The abnormal voltage detection unit 405 detects whether or not the B terminal voltage is an overvoltage based on the signal Vbsing.

  The negative arm short circuit unit 406 of the microcomputer 403 provides a gate signal for conducting the switching elements 224a to 224c and 226a to 226c of the negative arm when the abnormal voltage detection unit 405 detects an overvoltage of the B terminal voltage. To the gate driver 404.

The detection result of the abnormal voltage detection unit 405 and the signal Ifsig output from the field current detection unit 402 are input to the field current control unit 407 of the microcomputer 403. The field current control unit 407 outputs a signal IfH ^* for performing on / off control of the field switching element 22 of the power conversion device 20 to the gate driver 404 based on these signals, thereby rotating the rotor winding. The current flowing in the line 7 is controlled.

In the gate driver 404, based on the gate signals UL ^* , VL ^* , WL ^* , XL ^* , YL ^* , ZL ^* output from the negative arm short circuit unit 406 of the microcomputer 403, the switching elements 224a to 224c of the power conversion device 20 are used. And outputs signals ULG, VLG, WLG, XLG, YLG, and ZLG for performing the gate operation of 226a to 226c to make the switching elements 224a to 224c and 226a to 226c conductive. Further, the gate driver 404 outputs a signal IfG for performing on / off operation of the field switching element 22 of the power converter 20 based on the signal IfH ^* output from the field current control unit 407 of the microcomputer 403. Thus, the field switching element 22 is switched.

  Here, the short-circuit operation of the negative arm will be described. The abnormal voltage detection unit 405 of the microcomputer 403 detects an overvoltage of the B terminal voltage based on the signal Vbsig output from the B terminal voltage detection unit 401. The overvoltage detection method for the B terminal voltage is performed as follows. For example, in the case of a 14 [V] system, about 18 [V] is set as an abnormal voltage detection threshold, and in the case of a 28 [V] system, about 34 [V] is set as an abnormal voltage detection threshold. Then, when the voltage value detected by the B terminal voltage detection unit 401 exceeds the abnormal voltage detection threshold, the abnormal voltage detection unit 405 detects that the B terminal voltage is an overvoltage.

  When the abnormal voltage detection unit 405 detects that the B terminal voltage is an overvoltage, the negative electrode side arm short-circuit unit 406 conducts the switching elements 224a to 224c and 226a to 226c of the negative side arm to conduct the first fixing. A three-phase short circuit between the child winding 301 and the second stator winding 302 is performed.

  On the other hand, when the abnormal voltage detection unit 405 does not detect that the B terminal voltage is an overvoltage, the negative arm short circuit unit 406 performs a three-phase short circuit between the first stator winding 301 and the second stator winding 302. Do not do.

  In the first embodiment, when an overvoltage is detected in this way, the three-phase short circuit between the first stator winding 301 and the second stator winding 302 is performed, thereby suppressing the boosting of the permanent magnet 41, Demagnetization is prevented.

  However, if the three-phase short circuit of the first stator winding 301 and the three-phase short circuit of the second stator winding 302 are simultaneously performed, an eddy current is generated in the permanent magnet 41 and the permanent magnet 41 generates heat. Therefore, in Embodiment 1, the timing for performing the three-phase short circuit is switched according to the rotation speed of the rotating electrical machine 100 as follows.

  In the first embodiment, cooling fans 51 and 52 are provided on the front side and the rear side of the permanent magnet 41 and the rotor winding 7. The respective air volumes of the cooling fans 51 and 52 increase and decrease in proportion to the rotation speed of the rotating electrical machine 100. The air flow rate of the rotor 13 is indicated by the difference between the air flow rate of the cooling fan 51 and the air flow rate of the cooling fan 52, and is set so that the air flow rate of the cooling fan 51 and the air flow rate of the cooling fan 52 are different. Therefore, the amount of air that is passed through the rotor 13 increases or decreases in proportion to the rotational speed of the rotating electrical machine 100. Therefore, when the rotation speed is high, the permanent magnet 41 and the rotor winding 7 are efficiently cooled by the cooling fans 51 and 52.

  Therefore, in the high rotation speed region, the negative-side arm short-circuit unit 406 simultaneously performs the three-phase short circuit of the first three-phase winding 301 and the three-phase short circuit of the second three-phase winding 302, thereby causing a phase short circuit. Even if the permanent magnet 41 generates heat due to the eddy current of control, the air volume becomes remarkably large, so that the demagnetization start temperature is not reached and demagnetization can be prevented. In addition, since the three-phase short circuit of the first three-phase winding 301 and the three-phase short circuit of the second three-phase winding 302 are simultaneously performed, the overvoltage decay time is fast, which affects other electronic devices. Can be prevented.

  On the other hand, in the low rotational speed region, the airflow of the cooling fans on both sides of the permanent magnet 41 and the rotor winding 7 is small. When the air volume is small, the rotor winding 7 generates heat, is thermally conducted to the permanent magnet 41, and the temperature of the permanent magnet 41 rises. Therefore, in the first embodiment, in order to suppress the generation of eddy current in the low rotation speed region, after performing the three-phase short circuit of the first three-phase winding, the three-phase of the second three-phase winding. Short circuit in order. As described above, in the low rotational speed region, the three-phase short circuit of the first three-phase winding 301 and the three-phase short circuit of the second three-phase winding 302 are not performed at the same time. Can be suppressed. As a result, since the temperature rise of the permanent magnet 41 due to eddy current can be suppressed, demagnetization can be prevented.

FIG. 5 is a graph showing the correlation of the temperature rise of the permanent magnet 41 with respect to the rotation speed of the rotating electrical machine 100.
In FIG. 5, the horizontal axis represents the rotational speed, and the vertical axis represents the surface temperature of the permanent magnet 41 and the amount of air that is passed through the rotor 13.
A solid line 501 indicates a change in the surface temperature of the permanent magnet 41 when the three-phase short circuit of the first three-phase winding 301 and the three-phase short circuit of the second three-phase winding 302 are simultaneously performed.
A broken line 502 indicates a change in the surface temperature of the permanent magnet 41 when the three-phase short-circuit control is performed according to the first embodiment of the present invention. As indicated by a broken line 502, according to the three-phase short-circuit control of the first embodiment, the permanent magnet 41 does not exceed the irreversible demagnetization start temperature.
A two-dot chain line 503 indicates a change in the surface temperature of the permanent magnet 41 in a normal state.
An alternate long and short dash line 504 indicates a change in the air volume of the cooling fans 51 and 52. As can be seen from FIG. 5, the air volume of the cooling fans 51 and 52 is proportional to the rotational speed.
A dotted line 505 indicates the irreversible demagnetization start temperature of the permanent magnet 41. In the example of FIG. 5, the irreversible demagnetization start temperature is set to 200.degree.

  By providing cooling fans 51 and 52 for cooling the rotor winding 7 and the permanent magnet 41 on both sides of the rotor core 4, the temperature of the permanent magnet 41 during normal power generation is equal to or less than the irreversible demagnetization start temperature. Designed to. In the example of FIG. 5, as indicated by a two-dot chain line 503, the maximum temperature of the permanent magnet 41 during normal power generation is about 160 ° C., which is lower than the irreversible demagnetization start temperature.

  Further, as indicated by the alternate long and short dash line 504, the air flow rate of the rotor 13 portion by the cooling fans 51 and 52 is proportional to the rotational speed. In the first embodiment, as indicated by lines 501 to 503, the permanent magnet 41 indicates the maximum temperature when the rotation speed is in the low rotation speed range of 2000 to 5000 r / min. When the input / output terminal is suddenly disconnected from the state where the power generation state is maintained, a three-phase short circuit is started so as to protect the overvoltage.

  When the three phases of the two sets of stator windings 301 and 302 are short-circuited at the same time, a current flows through the coil of the rotating electrical machine 100 due to the counter electromotive force at the time of the short-circuit, and the magnetic poles of the stator 5 are magnetized. When the permanent magnet 41 of the rotating electrical machine 100 passes near the magnetized magnetic pole, the magnetic field penetrating the permanent magnet 41 increases and decreases, and an eddy current is generated in the permanent magnet 41. The heat generation of the permanent magnet 41 due to this eddy current is added, and as shown by the solid line 501 in FIG. 5, the irreversible demagnetization start temperature exceeds 200 ° C. and demagnetizes.

  Therefore, in the first embodiment, in the low rotational speed range of 2000 r / min or more and 5000 r / min or less, when the input / output terminal voltage becomes an overvoltage, the three-phase short circuit of the first stator winding 301 is performed. After performing, the three-phase short circuit of the second stator winding 302 is sequentially performed. Thereby, generation | occurrence | production of an eddy current can be prevented, the temperature increase of the permanent magnet 41 can be suppressed, and demagnetization can be prevented.

  On the other hand, in the high rotational speed range exceeding 5000 r / min, the three-phase short circuit of the first stator winding 301 and the three-phase short circuit of the second stator winding 302 are simultaneously performed. In the high rotation speed region, the air flow of the cooling fans 51 and 52 becomes remarkably large. Therefore, even if the permanent magnet 41 generates heat due to the eddy current of the phase short-circuit control, the permanent magnet 41 is cooled by the cooling air of the cooling fans 51 and 52. Therefore, the permanent magnet 41 does not reach the irreversible demagnetization start temperature of 200 ° C. Thereby, demagnetization can be prevented. In addition, since the three-phase short circuit is simultaneously performed, the overvoltage decay time is fast, and it is possible to prevent other electronic devices from being affected.

  As described above, in the first embodiment, when the abnormal voltage detection unit 405 detects an overvoltage of the B terminal voltage, in the low rotation speed region where the rotation speed of the rotating electrical machine 100 is 2000 to 5000 r / min, the first After the three-phase short-circuit of the stator winding 301, the three-phase short-circuit of the second stator winding 302 is sequentially performed. On the other hand, in the high rotational speed range exceeding 5000 r / min, the first stator The three-phase short circuit of the winding 301 and the three-phase short circuit of the second stator winding 302 are simultaneously performed. Thereby, as indicated by a broken line 502 in FIG. 5, according to the three-phase short-circuit control of the first embodiment, the permanent magnet 41 does not exceed the irreversible demagnetization start temperature.

  If the rotational speed is less than 2000 r / min, the three-phase short circuit of the first stator winding 301 and the three-phase short circuit of the second stator winding 302 may be performed in order, even if they are performed simultaneously. Or either. When the rotational speed is very low, no eddy current is generated even if three-phase short-circuiting is performed at the same time. Therefore, the temperature of the permanent magnet 41 does not reach the irreversible demagnetization start temperature of 200 ° C.

  Thus, in the first embodiment, the threshold value of the rotational speed defining the low rotational speed range is set in advance, and in the high rotational speed range where the rotational speed is larger than the threshold value, the two sets of stator windings Three-phase short-circuiting is performed at the same time. In a low rotation speed range where the rotation speed is equal to or lower than the threshold value, one stator winding is short-circuited and then the other stator winding is short-circuited. In the first embodiment, the threshold is set to 5000 r / min. This threshold value is appropriately set in advance by design data or experiment. Further, only the upper limit value (5000 r / min) for defining the low rotation speed range may be set as the threshold value for defining the low rotation speed range, or the upper limit value for defining the low rotation speed range ( Both 5000 r / min) and the lower limit (2000 r / min) may be set. By doing so, the temperature increase of the permanent magnet 41 can be suppressed and demagnetization can be prevented in both the low rotation speed range and the high rotation speed range.

As described above, in the first embodiment, the rotating electrical machine 100 is wound around the rotor core 4 and the rotor core 4 provided with the claw portions 4a and 4b made of a plurality of claw-shaped magnetic pole pieces on the outer periphery. A rotor 13 having a rotor winding 7 mounted thereon, a stator core 3 disposed opposite to the outer periphery of the rotor core 4 and having a plurality of slots formed on the inner periphery, and inserted into the slots. Between the stator 5 having the stator windings 301 and 302 wound around the stator core 3 and the adjacent claws 4a and 4b of the rotor core 4, and the adjacent claws Permanent magnet 41 magnetized in a direction to reduce the leakage magnetic flux between the parts 4a and 4b, and two cooling fans provided on both sides of the rotor core 4 for cooling the rotor winding 7 and the permanent magnet 41 51, 52, switching elements 223, 225 of the positive side arm and scanning of the negative side arm The power conversion unit 21 configured to convert the direct current and the alternating current of the power input from the input / output terminal, the switching elements 223 and 225 of the positive side arm, and the switching elements 224 of the negative side arm. The control apparatus 30 which performs on / off control of 226, and the rotational speed detection part 10 which detects the rotational speed of the rotary electric machine 100 are provided.
The stator windings are formed by winding two stator windings 301 and 302, which are multiphase-connected, around the stator core 3 independently of each other. Phase winding 302. The control device 30 includes an abnormal voltage detection unit 405 that detects whether or not the voltage value of the input / output terminal is equal to or higher than a preset threshold voltage, and the abnormal voltage detection unit 405 detects that the voltage value of the input / output terminal is equal to or higher than the threshold voltage. When it is detected that the switching elements 224 and 226 of the negative side arm of the first multiphase winding 301 and the second multiphase winding 302 are made conductive, the multiphase short circuit of the first multiphase winding 301 is detected. And a negative-side arm short-circuit portion 406 that performs multi-phase short-circuiting of the second multi-phase winding 302.
When the abnormal voltage detection unit 405 detects that the voltage value of the input / output terminal is equal to or greater than the threshold value, the control device 30 determines that the rotation speed detected by the rotation speed detection unit 10 is greater than a preset threshold value. The negative side arm short-circuit unit 406 simultaneously performs the multi-phase short circuit of the first multi-phase winding 301 and the multi-phase short circuit of the second multi-phase winding 302, and the rotation speed detected by the rotation speed detection unit 10 is determined in advance. When the threshold value is less than or equal to the set threshold value, the negative electrode side arm short-circuit unit 406 performs multi-phase short-circuiting of the first multi-phase winding 301 and then multi-phase short-circuiting of the second multi-phase winding 302.
In this way, after the three-phase short circuit of the first stator winding 301 is performed when the input / output terminal voltage becomes an overvoltage in the low rotational speed region where the rotational speed is equal to or lower than a preset threshold value, By sequentially performing the three-phase short circuit of the second stator winding 302, the generation of eddy current can be prevented, the temperature rise of the permanent magnet 41 can be suppressed, and demagnetization can be prevented.
On the other hand, in the high rotation speed range where the rotation speed is larger than a preset threshold value, the air flow of the cooling fans 51 and 52 becomes remarkably large. Therefore, even if the permanent magnet 41 generates heat due to the eddy current of the phase short-circuit control, the cooling fan 51 , 52 cools the permanent magnet 41 efficiently, so that the permanent magnet 41 does not reach the irreversible demagnetization start temperature of 200 ° C. Thereby, demagnetization can be prevented. In addition, since the three-phase short circuit is simultaneously performed, the overvoltage decay time is fast, and it is possible to prevent other electronic devices from being affected.
In the above-described embodiment, the first and second stator windings 301 and 302 are three-phase windings. However, the present invention is not limited to this, and for example, the first and second stator windings. Each of the wires 301 and 302 may be a five-phase winding or a seven-phase winding, and in either case, the same effect can be obtained.

  1 Front bracket, 2 Rear bracket, 3 Stator core, 4 Rotor core, 4a, 4b Claw, 5 Stator, 6 Rotor shaft, 7 Rotor winding, 8 Slip ring, 9 Brush, 10 Magnetic pole position detection Sensor, 12 Pulley, 13 Rotor, 20 Power converter, 21 Power converter, 22a Terminal, 22 Field switching element, 23 Heat sink, 24 B terminal, 30 Controller, 40 Control circuit board, 41 Permanent magnet, 51 Front Side cooling fan, 52 rear side cooling fan, 61 front side bearing, 62 rear side bearing, 71 substrate housing case, 90 brush holder, 100 rotating electrical machine, 101 bolt, 102 rotating electrical machine main body, 111 sensor rotor, 112 sensor stator 113 Sensor winding, 221 Field switching element 223a, 223b, 223c Three-phase upper arm switching element, 224a, 224b, 224c Three-phase lower arm switching element, 225a, 225b, 225c Three-phase upper arm switching element, 226a, 226b, 226c Three-phase Lower arm switching element, 301, 302 Stator winding, 401 Terminal voltage detector, 402 Field current detector, 403 Microcomputer, 404 Gate driver, 405 Abnormal voltage detector, 406 Negative arm short circuit, 407 Field current Control unit.

Claims (3)

A rotating electrical machine for a vehicle that exchanges DC power and AC power,
A rotor provided with a rotor core provided with a plurality of claw-shaped magnetic pole pieces on the outer periphery, and a rotor winding wound around the rotor core;
A stator core disposed opposite to the outer periphery of the rotor core and having a plurality of slots formed on the inner periphery thereof, and a stator winding inserted into the slot and wound around the stator core. A stator and
A permanent magnet disposed between adjacent claw-shaped pole pieces of the rotor core and magnetized in a direction to reduce leakage magnetic flux between the adjacent claw-shaped pole pieces;
Two cooling fans provided on both sides of the rotor core for cooling the rotor winding and the permanent magnet;
A power conversion unit that is configured by a switching element of the positive side arm and a switching element of the negative side arm, and converts between direct current and alternating current of power input from the input / output terminal;
A control device that performs on / off control of the switching element of the positive arm and the switching element of the negative arm;
A rotation speed detection unit that detects a rotation speed of the vehicular rotating electrical machine,
The stator winding includes a first multiphase winding and a second multiphase winding, which are formed by independently winding two windings connected in a multiphase manner around the stator core,
The controller is
An abnormal voltage detector that detects whether the voltage value of the input / output terminal is equal to or higher than a preset threshold voltage;
When the abnormal voltage detector detects that the voltage value of the input / output terminal is equal to or higher than the threshold voltage, the switching element of the negative arm of the first multiphase winding and the second multiphase winding And conducting a multi-phase short circuit of the first multi-phase winding and a multi-phase short circuit of the second multi-phase winding, the negative electrode side arm short-circuit portion,
The control device is
When the abnormal voltage detection unit detects that the voltage value of the input / output terminal is equal to or higher than the threshold voltage,
When the rotation speed detected by the rotation speed detection unit is larger than a preset threshold value, the negative multi-phase winding and the second multi-phase winding are caused by the negative-side arm short-circuit unit. Simultaneous multi-phase short circuit
When the rotation speed detected by the rotation speed detection unit is less than or equal to a preset threshold, the second multi-phase winding of the first multi-phase winding is short-circuited by the negative electrode side arm short-circuit unit, and then the second Perform multi-phase short circuit of multi-phase winding,
Rotating electric machine for vehicles.   The rotating electrical machine for a vehicle according to claim 1, wherein an air flow rate of the rotor portion generated by the cooling fan increases and decreases in proportion to the rotational speed of the rotating electrical machine for the vehicle. A front bracket and a rear bracket for supporting the stator core;
The rotation speed detection unit includes a sensor rotor fixed to a rear side end of a rotor shaft of the rotor, a sensor stator fixed to the rear bracket so as to face the sensor rotor, and the sensor A sensor winding fixed to the stator,
The rotating electrical machine for a vehicle according to claim 1 or 2.

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