JP2010246195A - Moving body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moving body which includes a rotating electrical machine that is operated efficiently in a wide range and besides is small. <P>SOLUTION: The moving body 10 includes the rotating electrical machine and a magnetic flux adjuster 18. The electrical rotating machine includes a stator 21 which includes a coil, a rotor which is arranged rotatably across an air gap on the stator 21 and is halved in the direction of a rotating shaft into a first rotor 24 and a second rotor 25 in each of which magnets for fields different in polarity are arranged alternately in the direction of rotation, and a variable magnetic flux mechanism 12 which varies the relative angle of the second rotor 25 of the rotor to the first rotor 24 of the rotor. The magnetic flux adjuster outputs a control signal for zeroing the relative angle between the first rotor 24 and the second rotor 25 to the variable magnetic flux mechanism, in case that the number of revolutions of the rotating electrical machine is not more than a preset threshold. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a moving body having a rotating electrical machine that changes magnetic flux.

  Instead of conventional induction motors (IM motors), permanent magnet synchronous motors (PM motors), which are excellent in efficiency and can be expected to be reduced in size and noise, are becoming popular. For example, PM motors have come to be used as drive motors for home appliances, railway vehicles, and electric vehicles. The IM motor generates a magnetic flux itself by an exciting current from the stator, and therefore has a problem that a loss is caused by flowing the exciting current. On the other hand, a PM motor is a motor that includes a permanent magnet in a rotor and outputs torque by using the magnetic flux thereof, so there is no such problem that the IM motor has.

  However, the PM motor generates an induced voltage in the armature coil in proportion to the rotation speed due to its permanent magnet. In an application range with a wide rotation range such as a railway vehicle or an automobile, the condition is that the inverter that drives and controls the PM motor is not destroyed by the overvoltage due to the induced voltage generated at the maximum rotation speed. In a PM motor having such characteristics, when performing constant output operation with a constant power supply voltage, as a measure for further increasing the aforementioned maximum rotational speed and widening the operation speed, a magnetic flux generated by a permanent magnet is applied to the armature coil. Although there is a so-called field weakening control in which an induced voltage is equivalently lowered by flowing a current that cancels the current, a current that does not contribute to torque is caused to flow, resulting in a decrease in efficiency. Moreover, it is necessary to flow a large current through the armature coil, which naturally increases the heat generated by the coil. For this reason, there is a possibility that the efficiency of the rotating electric machine in the high rotation region may be reduced, the permanent magnet may be demagnetized due to heat generation exceeding the cooling capacity, and the like.

  The variable magnetic flux motor having the structure described in Patent Document 1 has been devised to alleviate the above problems. The rotating electrical machine described in this publication has a rotor in which a rotor is divided into two in the direction of the rotation axis, and field magnets having different polarities are alternately arranged in the rotation direction. Since this rotating electric machine can change the effective magnetic flux by changing the phase of the rotor divided into two, it does not require field-weakening control accompanied by a reduction in efficiency in a high rotation region. Thereby, high-efficiency driving can be realized in a wide operating range.

Japanese Patent Laid-Open No. 2004-64942

  However, the rotating electrical machine described above requires a mechanism for applying an external force in order to operate the effective magnetic flux, and the mechanism division becomes large. Since the mounting area is limited in applications such as vehicles, it is desirable to make the rotating electrical machine as small as possible.

  An object of the present invention is to provide a moving body that can perform high-efficiency operation in a wide operation range and has a small rotating electric machine.

  In order to solve the above-described problems, the present invention provides a stator having windings, and a stator that is rotatably disposed through a gap, and is arranged on a first rotor and a second rotor in a rotation axis direction. A variable rotor that is divided in two and each of which has a field magnet of different polarity alternately arranged in the rotation direction and the relative angle of the second rotor of the rotor with respect to the first rotor of the rotor is variable. When a rotating electrical machine having a magnetic flux mechanism and the rotational speed of the rotating electrical machine is equal to or less than a predetermined threshold value, a control signal is output to the variable magnetic flux mechanism so that the relative angle between the first rotor and the second rotor is zero. And a magnetic flux adjusting means.

  Further, a stator having windings, and a stator that is rotatably arranged through a gap, and is divided into a first rotor and a second rotor in the direction of the rotation axis, each having a different polarity. A rotating electrical machine comprising: a rotor in which magnets for magnetism are alternately arranged in the rotation direction; and a variable magnetic flux mechanism that varies a relative angle of the second rotor of the rotor with respect to the first rotor of the rotor; And a magnetic flux adjusting means for outputting a control signal for maximizing the relative angle between the first rotor and the second rotor to the variable magnetic flux mechanism when the rotational speed of the rotating electrical machine is equal to or greater than a predetermined threshold. The configuration is as follows.

  It is possible to provide a moving body that can perform high-efficiency operation in a wide operation range and has a small rotating electric machine.

It is a figure which shows one Example of the moving body which has the rotary electric machine which concerns on this invention. It is a figure which shows one structural example of the rotary electric machine which concerns on this invention. It is a figure which shows one operation example of the magnetic flux adjustment means of this invention. It is a figure explaining the reason which makes effective magnetic flux the maximum in the zero speed vicinity in the magnetic flux adjustment means of this invention. It is a figure explaining the shutdown operation of the control means of this invention. It is a figure which shows the other Example of the moving body which has the rotary electric machine which concerns on this invention.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an overall view of a moving body 10 having a rotating electrical machine such as a variable magnetic flux motor 11 according to the present invention.

  The moving body 10 includes a variable magnetic flux motor 11 and a variable magnetic flux mechanism 12 that varies the magnetic flux of the variable magnetic flux motor 11, and the variable magnetic flux mechanism 12 can be realized by an actuator such as an electric actuator or a hydraulic actuator, a clutch, a brake, or the like.

  Moreover, it has the rotation speed sensor 13 which is a rotation speed detection means which detects the rotation speed of rotary electric machines, such as the variable magnetic flux motor 11, and can implement | achieve, for example with a pulse encoder and a resolver.

  Further, based on a command signal from the control means 17, an inverter 14 that drives the variable magnetic flux motor 11, a DC power supply means 15 that supplies DC power to the variable magnetic flux motor 11, and a variable magnetic flux mechanism operating means that operates the variable magnetic flux mechanism 12. 16, the control means 17 which calculates the drive torque required for the moving body 10, and the magnetic flux adjustment means 18 are provided. The drive torque is sent as a command signal to the inverter 14 and the variable magnetic flux mechanism operating means 16. The magnetic flux adjusting means 18 is disposed between the control means 17 and the variable magnetic flux mechanism operating means 16. The magnetic flux adjusting means 18 adjusts a command signal to the variable magnetic flux mechanism operating means 16 based on the rotational speed information obtained from the rotational speed sensor 13. The operation of the magnetic flux adjusting means 18 will be described later with reference to FIG. Further, the differential mechanism 19 transmits torque obtained from the variable magnetic flux motor 11 to the axle, and gives driving force to the moving body 10.

  FIG. 2 is a schematic diagram of the variable magnetic flux motor 11 of the rotating electrical machine. In particular, the variable magnetic flux mechanism 12 is illustrated as having an actuator.

  The variable magnetic flux motor 11 is disposed on a stator 21 that is a stator having a winding (coil 22), an output shaft 23, and the stator 21 that is a stator so as to be rotatable through a gap, and is first in the direction of the rotation axis. The rotor 24 and the second rotor 25 are divided into two, each having a rotor in which field magnets having different polarities are alternately arranged in the rotation direction. A spline 26 is provided on the surface of the output shaft 23. Since the second rotor 25 moves along the spline 26, the magnetic flux directions of the first rotor 24 and the second rotor 25 can be changed by adjusting the axial position.

  The variable magnetic flux mechanism 12 varies the relative angle of the second rotor 25 with respect to the first rotor 24 and adjusts the axial position. The variable magnetic flux motor 11 has a push plate 27 and a thrust bearing 28. The variable magnetic flux mechanism 12 changes the position of the second rotor 25 in the direction of the output shaft 23 by pushing or pulling the push plate 27. Can be made. A detailed description of the variable magnetic flux motor is described in Patent Document 1 described above.

  FIG. 3 shows the operation of the magnetic flux adjusting means 18. Here, the horizontal axis N is the rotational speed of the variable magnetic flux motor 11, and the vertical axis T is the required torque. Here, Φ represents an effective magnetic flux. The effective magnetic flux here is the amount of magnetic flux that contributes to the rotational torque of the rotating electrical machine. It is obtained from the rotational torque of the rotating electrical machine and the current flowing through the stator winding.

  When the rotational speed of the variable magnetic flux motor 11 is equal to or less than a predetermined threshold, the magnetic flux adjusting means 18 sends a control signal for setting the relative angle between the first rotor 24 and the second rotor 25 to 0 to the variable magnetic flux mechanism 12. A control signal is generated so that the effective magnetic flux Φ is maximized when output is performed, that is, when the rotational speed of the variable magnetic flux motor 11 is equal to or less than the zero speed determination speed ω0. The zero speed determination speed ω0 is a predetermined rotation speed as a threshold value for determining whether the variable magnetic flux motor 11 is stationary or driven, and is set to be equal to or less than the maximum torque generation limit speed ωn. That is, it is set below the maximum number of revolutions that can generate the maximum torque. Here, the maximum torque generation limit speed ωn is defined as the maximum speed at which the variable magnetic flux motor 11 can generate the maximum torque.

  FIG. 4 shows the reason why the effective magnetic flux Φ is maximized in the vicinity of zero speed. Here, the horizontal axis represents the rotational speed of the variable magnetic flux motor 11, and the vertical axis represents the thrust of the variable magnetic flux mechanism 12 necessary for varying the magnetic flux. When the motor rotation speed is 0, in order to operate the effective magnetic flux Φ, it is necessary to give a thrust to overcome the cogging torque generated by the magnetic flux of the motor in addition to the frictional force. However, once the motor starts to rotate, the influence of the cogging torque is almost eliminated, and the effective magnetic flux Φ can be changed only by applying a thrust to overcome the friction.

  It is desirable that the moving body is set so that the maximum torque can be generated at low speed. Therefore, if the effective magnetic flux Φ is always maximized when the moving body 10 is stationary, it is not necessary to operate the effective magnetic flux Φ at zero speed, and the variable magnetic flux mechanism 12 generates a thrust that overcomes the friction. It will suffice if it is designed to be possible.

  As a result, the thrust required by the variable magnetic flux mechanism 12 can be reduced, and the variable magnetic flux mechanism 12 can be reduced in size. That is, since it is not necessary to vary the magnetic flux when the rotational speed is 0, the influence of cogging torque, which is a problem when the rotational speed is 0, can be ignored. As a result, it is possible to reduce the physique of the variable magnetic flux mechanism 12 and contribute to the miniaturization of the entire variable magnetic flux motor 11.

  Further, the magnetic flux adjusting means 18 sends a control signal for maximizing the relative angle between the first rotor and the second rotor to the variable magnetic flux mechanism 12 when the rotational speed of the variable magnetic flux motor 11 is equal to or greater than a predetermined threshold value. Output. That is, when the rotational speed of the variable magnetic flux motor 11 is higher than the high speed determination speed ωh, the effective magnetic flux is forcibly made the lowest. The high speed determination speed ωh is set lower than the rotational speed ωm of the variable magnetic flux motor 11 that realizes the assumed maximum speed of the moving body 10. Here, the assumed maximum speed is determined in advance based on state information such as the weight of the moving body 10, and a threshold value is set to be equal to or lower than the maximum rotation speed determined by the assumed maximum speed.

  Therefore, since it is ensured that the magnetic flux is minimum in high-speed traveling, it is possible to prevent the induced voltage due to high-speed traveling from being excessively increased and to set the breakdown voltage of the inverter 14 low. Lowering the withstand voltage of the inverter 14 contributes to miniaturization and cost reduction of electric parts such as inverter elements, and the rotating electric machine and the moving body 10 equipped with the rotating electric machine can be provided in a small size and at low cost.

  In general, when an abnormality is found during traveling, the mobile body first returns to normal operation, and shifts to the degenerate operation mode when the operation can be continued even if the recovery fails. When the operation cannot be continued, a shutdown operation is performed to stop the system in order to avoid the spread of damage and the uncontrollable state. Here, the term “shutdown” refers to outputting to the DC power supply means 15 a command signal for stopping the energy supplied to the power source.

  Here, the abnormality of the moving body means that the detected vehicle state variables (moving body speed, accelerator opening, etc.) and motor state variables (rotation speed, rotation speed, generated torque, etc.) are predetermined state variables. Is different. For example, this is the case when the relationship between the detected vehicle speed and the motor rotation speed is different from the relationship between the motor rotation speed at a predetermined vehicle speed. Specifically, for example, the vehicle speed detected by the control means of the moving body is 40 km / h and the motor rotation speed is 6000 rpm, even though it is appropriate that the motor rotates at 2000 rpm when the vehicle speed is 40 km / h. When it becomes, it judges that it is abnormal. In such a state, the gear may be disengaged from the motor shaft and the motor may be in an unloaded state.In this case, the rotation speed of the motor increases rapidly, causing damage to the bearings and associated peripheral devices. There is a possibility of reaching.

  FIG. 5 shows a shutdown sequence in the case where an abnormality while traveling is detected in the moving body 10 according to the present invention. The shutdown sequence refers to a series of procedures executed when the system is shut down.

  If an abnormality is found, the control means 17 acquires the current motor rotation speed ω. The current motor rotational speed ω is first compared with the zero speed determination speed ω0 that is the threshold described in FIG. Here, if the current motor rotation speed ω is smaller than a predetermined threshold zero speed determination speed ω 0, the motor is a region that is greatly affected by the cogging torque shown in FIG. After performing the magnetic flux maximization processing so that the maximum torque can be exhibited at the time of return, a command signal for stopping the power supplied to the motor which is the rotating electrical machine is output to the DC power supply means 15 and the shutdown is performed. Note that the magnetic flux maximization processing specifically refers to setting the relative angle between the first rotor 24 and the second rotor 25 to zero. The control unit 17 includes such a shutdown unit.

  On the other hand, if the current motor rotation speed ω does not fall below the zero speed determination speed ω0, the current motor rotation speed ω is compared with the high speed determination speed ωh that is the threshold described in FIG. Here, if the current motor rotation speed is larger than the predetermined threshold high speed determination speed ωh, the motor will rotate after performing the magnetic flux minimization process to alleviate the influence of high induced voltage due to high speed rotation. A command signal for stopping power supplied to the motor, which is an electric machine, is output to the DC power supply means 15 to perform shutdown. Note that the magnetic flux minimization processing specifically refers to maximizing the relative angle between the first rotor 24 and the second rotor 25. The control unit 17 includes such a shutdown unit.

  If it is neither of the above, the motor is not particularly burdened, so the shutdown can be performed as it is. In FIG. 5, for the sake of simplification of description, the configuration is such that the shutdown is performed as it is. However, after the motor rotational speed is gradually decreased to satisfy the state of ω <ω0, the magnetic flux maximization processing is performed and the configuration may be configured to shut down. it can.

  When shutting down with a large effective magnetic flux during high-speed rotation, control that cancels the induced voltage cannot be performed, so the rotating electrical machine must be designed to withstand the maximum value of the generated induced voltage, That builds up. However, by setting the shutdown sequence as shown in FIG. 5, the effective magnetic flux can be minimized and shut down during high-speed rotation, so that the maximum value of the induced voltage can be kept small, and the physique is compact. Can be expected. Further, when the motor rotational speed is 0, the effective magnetic flux amount is maximized and then shut down, so that it is not necessary to change the magnetic flux at the time of restart after repair. The effect that 12 can be reduced in size is acquired. In other words, the magnetic flux can be appropriately maximized or minimized when the shutdown at the time of abnormality is necessary, so that the design margin at the time of abnormality can be reduced. As a result, there is an effect that the electrical system and the mechanical system can be downsized.

  FIG. 6 is a view showing another embodiment of the moving body having the rotating electrical machine of the present invention. In this embodiment, a speed governor (governor 31) that mechanically adjusts the rotational speed of the rotor is used as the variable magnetic flux mechanism 12 of FIG. The governor 31 includes a spring 32, a weight 33, and a link mechanism 34. In the region where the rotational speed is low, the push plate 27 and the second rotor 25 shown in FIG. 2 are pushed in by the effect of the spring 32, and the effective magnetic flux becomes maximum. On the other hand, the push plate 27 and the second rotor 25 are pulled out by the centrifugal force acting on the weight 33 during high-speed rotation, and the effective magnetic flux is reduced. Thus, the magnetic flux adjusting means 18 can also be realized by mechanical means such as the governor 31.

  In FIG. 1, the rotational speed sensor 13 is used as the rotational speed detection means. However, when the sensorless control means is provided, the same effect can be obtained even if the estimated speed value provided by the sensorless control means is used. Further, in the configuration as shown in FIG. 1, since the variable magnetic flux motor 11 and the vehicle drive shaft are directly connected, the rotational speed of the variable magnetic flux motor 11 and the vehicle speed are in a proportional relationship. Therefore, the same effect can be obtained even if a vehicle speed sensor is used.

  Further, when the gasoline engine and the variable magnetic flux motor 11 are directly connected as in a parallel hybrid vehicle, an engine speed sensor or a crank angle sensor can be used instead.

  In FIG. 1, the control means 17 and the magnetic flux adjusting means 18 are separated. In this configuration, the control means 17 sets the amount of the effective magnetic flux Φ obtained by, for example, loss minimization control, and the magnetic flux adjustment means 18 gives the magnetic flux restriction as shown in FIG. However, even if the control means 17 and the magnetic flux adjusting means 18 are mounted on one CPU, the effect of the present invention can be obtained. When mounting on one CPU, if the results of the control means 17 and the magnetic flux adjusting means 18 contradict each other, the magnetic flux adjusting means 18 may be prioritized.

DESCRIPTION OF SYMBOLS 10 Mobile body 11 Variable magnetic flux motor 12 Variable magnetic flux mechanism 13 Rotation speed sensor 14 Inverter 15 DC power supply means 16 Variable magnetic flux mechanism operation means 17 Control means 18 Magnetic flux adjustment means 19 Differential mechanism 21 Stator 22 Coil 23 Output shaft 24 First Rotor 25 Second rotor 26 Spline 27 Push plate 28 Thrust bearing 31 Governor 32 Spring 33 Weight 34 Link mechanism

Claims (10)

A stator having windings;
The stator is rotatably arranged through a gap, and is divided into a first rotor and a second rotor in the rotation axis direction, and field magnets having different polarities are alternately arranged in the rotation direction. An arranged rotor,
A rotating electrical machine having a variable magnetic flux mechanism that varies a relative angle of the second rotor of the rotor with respect to the first rotor of the rotor;
Magnetic flux adjusting means for outputting a control signal for setting the relative angle between the first rotor and the second rotor to 0 to the variable magnetic flux mechanism when the rotational speed of the rotating electrical machine is equal to or less than a predetermined threshold; A moving body having. The mobile body according to claim 1,
The magnetic flux adjusting means is a moving body that outputs a control signal that maximizes the effective magnetic flux when the rotational speed of the rotating electrical machine is equal to or less than a predetermined threshold value. The mobile body according to claim 1,
In the rotating electrical machine system, the threshold value is set to be equal to or lower than a maximum rotational speed capable of generating a maximum torque. A stator having windings;
The stator is rotatably arranged through a gap, and is divided into a first rotor and a second rotor in the rotation axis direction, and field magnets having different polarities are alternately arranged in the rotation direction. An arranged rotor,
A rotating electrical machine having a variable magnetic flux mechanism that varies a relative angle of the second rotor of the rotor with respect to the first rotor of the rotor;
Magnetic flux adjusting means for outputting a control signal that maximizes the relative angle between the first rotor and the second rotor to the variable magnetic flux mechanism when the rotational speed of the rotating electrical machine is equal to or greater than a predetermined threshold; A moving body having. The mobile body according to claim 4,
The magnetic flux adjusting means is a moving body that outputs a control signal that minimizes the effective magnetic flux when the rotational speed of the rotating electrical machine is equal to or greater than a predetermined threshold. The mobile body according to claim 4,
In the rotating electrical machine system, the threshold value is set to be equal to or less than a maximum rotational speed determined by a predetermined assumed maximum speed of the moving body. In the moving body according to claim 1 or 4,
A moving body having a rotational speed detection means for detecting the rotational speed of the rotating electrical machine. The mobile body according to claim 1,
Control means for calculating the driving torque required for the moving body;
DC power supply means for supplying power to the rotating electrical machine,
When the rotation of the rotating electrical machine is smaller than the threshold when the control unit detects an abnormality of the moving body, the rotation angle is set to 0 after the relative angle between the first rotor and the second rotor is set to 0. A moving body having shutdown means for outputting a command signal for stopping power supplied to an electric machine to the DC power supply means. The mobile body according to claim 4,
Control means for calculating the driving torque required for the moving body;
DC power supply means for supplying power to the rotating electrical machine,
The control means detects the abnormality of the moving body, and when the rotational speed of the rotating electrical machine is greater than the threshold, the relative angle between the first rotor and the second rotor is maximized, and then the rotation A moving body having shutdown means for outputting a command signal for stopping power supplied to an electric machine to the DC power supply means. In the moving body according to claim 1 or 4,
The variable magnetic flux mechanism is a moving body that is a governor that mechanically regulates the rotational speed of the rotor.

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