JP6097494B2 - Electric vehicle drive system - Google Patents

Description

  The present invention relates to an electric vehicle drive system for driving an electric vehicle equipped with an electric motor.

  The structure and function of a generally known electric vehicle will be described with reference to FIGS. 8 and 9. The vehicle body 100 is placed on two front and rear carts 120. Each carriage 120 includes two sets of wheel shafts 123 in which left and right wheels 121L and 121R are coupled by an axle 122. The wheel shaft 123 is supported by the carriage 120 in a rotatable state. A plurality of main electric motors 125 are provided for each carriage 120, and each main electric motor 125 is loaded on the carriage frame 126 and drives the wheel shaft 123 via the joint 127 and the driving device 128. Although the main motor 125 may be driven by an individual inverter, in the illustrated example, each main motor 125 is electrically connected to the common inverter 140 in parallel.

  In general, when the wheelset 123 idles during rainy weather or the like, the inverter 140 is controlled so that the torque of the main motor 125 is reduced, thereby returning from the idling state. Since each main motor 125 is connected in parallel to the common inverter 140, the torque of each main motor 125 cannot be individually controlled. Therefore, a drive system that controls all the main motors connected in parallel as shown in the figure has been proposed (for example, Patent Document 1).

  Further, as a method for controlling the main motor, there has been proposed a method for suppressing the vehicle body vibration by indirectly suppressing the vehicle body vibration by changing the torque of the main motor (for example, Patent Document 2).

  In an ordinary electric railway vehicle, an integrated wheel shaft in which left and right wheels are coupled is used. However, in a low-floor vehicle, a variable train between gauges, a mechanism in which the left and right wheels can rotate independently may be provided. However, the left and right independent rotating wheels have a problem that they do not have a self-steering mechanism that a normal wheel shaft has. Thus, a method has been proposed in which left and right wheels are driven by different main motors and steering control is performed using a torque difference between the left and right main motors (for example, Patent Document 3).

JP 2002-325307 A JP 2011-101555 A JP 7-132823 A

  In an electric vehicle, an induction motor is generally used as a main motor, but a permanent magnet synchronous motor that is smaller and more efficient than an induction motor can also be used. However, in the permanent magnet synchronous motor, the torque varies as the rotor phase varies. In an electric vehicle, the rotational phase of the main motor may fluctuate due to wheel diameter difference, idling, etc., and therefore cannot be connected in parallel when the main motor is a permanent magnet synchronous motor. Therefore, an inverter must be prepared for each main motor, resulting in an increase in cost and an increase in equipment mounting space.

  Further, since the torque is controlled by the average torque of the main motors connected in parallel at the time of parallel connection, the torque of each main motor cannot be changed. As a result, fine slip and re-adhesion control becomes impossible. In the vibration control disclosed in Patent Document 2, it is necessary to superimpose torques of opposite phases on the two main motors in the carriage, so it is necessary to individually control the two main motors in the carriage. Therefore, in order to carry out fine idling / re-adhesion control and vibration control, an inverter must be prepared for each main motor, resulting in an increase in cost and an increase in equipment mounting space.

  The left and right independent rotating wheels disclosed in Patent Document 3 also need to be driven by different inverters in order to generate different torques on the left and right wheels. In particular, since the left and right wheels are driven by different main motors in the left and right independent rotation, the number of inverters is further doubled.

  Therefore, an object of the present invention is to provide an electric vehicle drive system capable of individually controlling the rotational speed and torque for each wheel or wheel shaft even when a plurality of main motors are connected in parallel to a common inverter.

The electric vehicle drive system of the present invention is electrically connected in parallel to a plurality of rotating members (23, 51L, 51R) that are wheel shafts or wheels and a common inverter (40, 60), each of which is a separate rotating member. In an electric vehicle drive system applied to an electric vehicle having a plurality of main motors (25) for driving the motor, each of the main motors has three elements (31, 32, 33) that are differentially rotated. A plurality of planetary gear mechanisms (30) provided one by one, and a plurality of auxiliary electric motors (35) provided one by one for each planetary gear mechanism, each of the plurality of planetary gear mechanisms, Any one of the plurality of main motors is connected to any one of the three elements, and any one of the plurality of rotating members is connected to any one of the remaining two elements of the three elements. And before 3 elements and is one of the two remaining one other element in said plurality of auxiliary motors are connected, by controlling the plurality of auxiliary motors, the respective operating state of the plurality of traction motors Auxiliary motor control means (42, 62) for controlling via the planetary gear mechanism is further provided .

  According to this electric vehicle drive system, a planetary gear mechanism is provided for each main motor connected in parallel to a common inverter, and an auxiliary motor is connected to each element of the planetary gear mechanism. For this reason, even if a plurality of main motors are connected in parallel to a common inverter and cannot be controlled for each main motor, the three elements of the planetary gear mechanism rotate differentially, so that the auxiliary motors are individually controlled. Thus, the rotational speed and torque can be changed for each rotating member that is a wheel or a wheel shaft. Therefore, even when a plurality of main motors are connected in parallel to a common inverter, the rotational speed and torque can be individually controlled for each wheel and wheel shaft.

In one aspect of the electric vehicle drive system of the present invention, each of the plurality of main motors is configured as a synchronous motor, and main motor control means (41, 61) that controls the plurality of main motors via the inverter. ) further wherein the auxiliary motor control means such that said each of the plurality of main motor is operated at the same rotational speed and rotation angle, may control the plurality of auxiliary motor. According to this aspect, each of the plurality of main motors is operated at the same rotation speed and rotation speed by the control of each auxiliary motor. Therefore, even if idling or the like occurs in any of the rotating members, it is possible to prevent variations in the rotation speeds and rotation angles of the plurality of main motors.

In one aspect of the electric vehicle drive system of the present invention, the auxiliary motor control means may indirectly change the output torques of the plurality of main motors by controlling the plurality of auxiliary motors.

  One aspect of the electric vehicle drive system of the present invention may further include a lock mechanism (55) capable of mechanically locking or releasing the rotation of at least one of the plurality of auxiliary motors. According to this aspect, when the rotation of the auxiliary motor is locked by the lock mechanism, the torque control of the rotating member corresponding to the auxiliary motor can be performed by controlling the main motor corresponding to the locked auxiliary motor. . Then, with the main motor controlled in this manner, the torque control of the remaining rotating members can be performed individually by controlling the auxiliary motor that is not locked. The lock mechanism may be provided for all of the plurality of auxiliary electric motors. Since the lock mechanism mechanically locks the rotation of the auxiliary motor, there is less damage to the auxiliary motor than when the rotation of the auxiliary motor is electrically locked, and electrical loss can be prevented from occurring. .

  As one aspect of the electric vehicle drive system of the present invention, each of the plurality of auxiliary motors may be configured as an ultrasonic motor. The ultrasonic motor has a feature capable of generating a large torque at a low speed, and is braked by friction when stopped. Therefore, since the rotation of the auxiliary motor can be easily restricted without power consumption, the same effect as the case where the lock mechanism described above is mounted can be expected.

  In the aspect provided with the auxiliary motor control means described above, two main motors are provided as the plurality of main motors, two auxiliary motors are provided as the plurality of auxiliary motors, and the auxiliary motor control means includes: The two auxiliary motors may have a common control unit (62) connected in reverse parallel so as to generate torques in opposite directions. By controlling the two auxiliary motors with a common control unit, the torque difference of the rotating member for each main motor can be controlled. Therefore, the torque of the two rotating members can be independently controlled by the common inverter provided for the two main motors and the common control unit provided for the two auxiliary motors. Therefore, the number of control units can be reduced as compared with the case where a control unit is prepared for each auxiliary motor. The connection in antiparallel means that the two auxiliary motors are connected in parallel to a common control unit in a state where the polarities of the two auxiliary motors are opposite to each other.

  In addition, in the above description, in order to make an understanding of this invention easy, the reference sign of the accompanying drawing was attached in parenthesis, but this invention is not limited to the form of illustration by it.

  As described above, according to the electric vehicle drive system of the present invention, a planetary gear mechanism is provided for each main motor connected in parallel to a common inverter, and an auxiliary motor is connected to each element of the planetary gear mechanism. Therefore, even if a plurality of main motors are connected in parallel to a common inverter and cannot be controlled for each main motor, the rotation speed and the rotation speed for each rotating member that is a wheel or a wheel shaft can be controlled by individually controlling the auxiliary motor. Torque can be changed. Therefore, even when a plurality of main motors are connected in parallel to a common inverter, the rotational speed and torque can be individually controlled for each wheel and wheel shaft.

The figure which showed an example of the trolley | bogie of the electric vehicle to which the electric vehicle drive system which concerns on one form of this invention was applied. The figure which showed the structure of the planetary gear mechanism from the rotating shaft direction. The figure which showed the structure of the planetary gear mechanism from the rotation radial direction. The figure which showed the outline of the control system of a main motor and an auxiliary motor. The figure which showed an example of the trolley | bogie which concerns on a 3rd form. The figure which showed the outline of the locking mechanism which concerns on a 4th form. The figure which showed the outline of the control system which concerns on a 5th form. The figure which showed the outline of the electric railway vehicle as a general electric vehicle. The figure which showed an example of the trolley | bogie provided in the vehicle of FIG.

(First form)
The cart 20 shown in FIG. 1 is applied to the electric vehicle as shown in FIG. That is, the two trucks 20 having the same structure support the body of the electric car. The carriage 20 includes two sets of wheel shafts 23 in which left and right wheels 21 </ b> L and 21 </ b> R traveling on the track R are coupled by an axle 22. The wheel shaft 23 is supported by the carriage 20 in a rotatable state. One main motor 25 is provided for each wheel shaft 23. Each main motor 25 is configured as a permanent magnet synchronous motor and is loaded on a carriage frame 26. Torque output from each main motor 25 is transmitted to the wheel shaft 23 via a planetary gear mechanism 30, a joint 27, and a drive device 28, which will be described later. The drive device 28 incorporates a gear train 29 as a power transmission mechanism.

  One planetary gear mechanism 30 is provided between each main motor 25 and each joint 27. As shown in FIGS. 2 and 3, the planetary gear mechanism 30 includes a sun gear 31, a ring gear 32, and a planet carrier 33 as three elements that perform differential rotation with respect to each other. The sun gear 31 is configured as an external gear. The ring gear 32 is disposed concentrically outside the sun gear 31 and is configured as an internal gear. The planet carrier 33 holds the planet gear 34 that meshes with each of the sun gear 31 and the ring gear 32 so as to rotate and revolve. Of the three elements of the planetary gear mechanism 30, the sun gear 31 is connected to the auxiliary motor 35, the ring gear 32 is connected to the main motor 25, and the planetary carrier 33 is connected to the wheel shaft 23 via the joint 27 and the drive device 28. Yes.

  As shown in FIG. 4, the main motors 25 are electrically connected to the common inverter 40 in parallel. One inverter 40 is mounted on one electric vehicle. That is, one inverter 40 is provided for a total of four main motors 25 mounted on the two carriages 20, and the torque and rotation speed of each main motor 25 are controlled via the inverters 40. The inverter 40 is controlled by the main control unit 41. The main control unit 41 corresponds to main motor control means according to the present invention. Further, one auxiliary control unit 42 is electrically connected to each of the plurality of auxiliary motors 35, and the torque and rotational speed of each auxiliary motor 35 are individually controlled by each auxiliary control unit 42. . Each auxiliary control unit 42 incorporates an electrical element such as an inverter. A combination of the four auxiliary control units 42 corresponds to auxiliary motor control means according to the present invention.

  The main control unit 41 controls the torque and rotational speed of each main motor 25 on average through the inverter 40 as required. Since each auxiliary motor 35 is connected to a sun gear 31 that is an element of the planetary gear mechanism 30, the operating state of each main motor 25 can be made uniform by controlling the rotational speed of each auxiliary motor 35 individually. It is possible to hold it. That is, each auxiliary control unit 42 of this embodiment controls the rotation speed of each auxiliary motor 35 so that each main motor 25 is operated at the same rotation speed and rotation angle. As a result, even if the rotational speed and the rotational angle of the respective wheel shafts 23 vary due to wheel diameter difference, idling, etc., the auxiliary motors 35 are controlled by the auxiliary control units 42, whereby the main motors 25 connected in parallel are controlled. The difference between the rotation speed and the rotation angle between the wheel shafts 23 can be compensated.

  Since each auxiliary motor 35 is sufficient if it can compensate for the difference in rotational speed of the wheel shaft 23, it is not necessary to make the rotational speed much higher than the rotational speed of the main motor 25. Since the planetary gear mechanism 30 amplifies the torque of the auxiliary motor 35, a larger torque than that of the main motor 25 is unnecessary. Therefore, it is sufficient that the auxiliary motor 35 is smaller than the main motor 25. Further, the inverter included in the auxiliary control unit 42 may have a smaller capacity than the inverter 40 to which the main motor 25 is connected.

(Second form)
In the second embodiment, the control content of the auxiliary control unit 42 is different. Since other matters are common to the first embodiment, description thereof is omitted. Each auxiliary control unit 42 controls each auxiliary electric motor 35 to change the torque for driving the wheel shaft 23, thereby performing motion control such as well-known idling / re-adhesion control and vibration control executed for the electric vehicle. I do. The details of the operation performed by the auxiliary control unit 42 when performing these controls differ depending on the configuration of the main motor 25.

  For example, when each main motor 25 is configured as an induction motor, the output torque changes according to the rotational speed difference of each main motor 25 connected in parallel to the inverter 40. Therefore, by operating each auxiliary motor 35 and controlling the rotation speed of each main motor 25, the output torque of each main motor 25 can be changed.

  Moreover, when each main motor 25 is comprised as a synchronous motor like a 1st form, a torque changes according to the rotation phase of each main motor 25 connected to the inverter 40 in parallel. Therefore, the output torque of each main motor 25 can be changed by operating each auxiliary motor 35 to control the rotational phase of each main motor 25.

  In any of these cases, the output torque of each main motor 25 can be indirectly changed by controlling each auxiliary motor 35 by the auxiliary control unit 42. Therefore, by operating each auxiliary motor 35 as described above according to the configuration of each main motor 25, the torque for driving each wheel shaft 23 can be changed. In the idling / re-adhesion control, fine control for each wheel shaft 23 is possible even when the main motors 25 are connected in parallel to the common inverter 40. Further, even if two main motors 25 provided on the common carriage 20 are connected in parallel, by operating the two auxiliary motors 35 provided corresponding to them, the antiphase Since torque can be superimposed, vibration control can be realized.

(Third form)
In the third embodiment, the present invention is applied to an electric vehicle including a left and right independent wheel carriage. In addition, the same code | symbol is attached | subjected to drawing in the structure which is common in each form mentioned above, and description is abbreviate | omitted. The carriage 50 has a pair of left and right wheels 51 </ b> L and 51 </ b> R that travel on the track R arranged in the front-rear direction. Hereinafter, when it is not necessary to distinguish between left and right, they are referred to as wheels 51. Although not shown, two electric vehicles according to the third embodiment are arranged with two carriages 50 in FIG. The carriage 50 is provided with one main motor 25, auxiliary motor 35, and planetary gear mechanism 30 for each wheel 51. Each of the main motor 25 and the auxiliary motor 35 is loaded on the carriage frame 52. Also in this embodiment, among the three elements of each planetary gear mechanism 30, the auxiliary motor 35 is connected to the sun gear 31, the main motor 25 is connected to the ring gear 32, and the wheels 51 are connected to the planet carrier 33.

  The main motor 25 and the auxiliary motor 35 are electrically connected in the same manner as in FIG. That is, each main motor 25 is connected in parallel to a common inverter 40, and each auxiliary motor 35 is connected to an auxiliary control unit 42 provided for each wheel 51. Control of each main motor 25 is performed simultaneously by the main control unit 41 via the inverter 40, and control of each auxiliary motor 25 is performed individually by each auxiliary control unit 42. Therefore, even when the main motors 25 are connected in parallel, the torque can be controlled for each wheel 51 by controlling the auxiliary motors 25 by the auxiliary control units 42. Therefore, since the respective torques of the left and right wheels 51L and 51R can be individually controlled, steering control well known in the field of electric vehicles can be realized. At the same time, motion control such as the idling / re-adhesion control and vibration control described above can be performed.

  In the case of an electric vehicle with left and right independent wheels, normally, eight inverters are required for each electric vehicle to drive all the wheels. In this embodiment, the number of inverters for controlling the main motor 25 is one. This is effective for cost reduction and miniaturization.

(4th form)
The fourth mode is characterized by a mechanism applied to the auxiliary motor 35 and can be applied to each mode described above. As shown in FIG. 6, the present embodiment is provided with a lock mechanism 55 that can mechanically lock or release the rotation of at least one of the plurality of auxiliary motors 35 described above. The lock mechanism 55 is provided between the motor shaft 35 a of the auxiliary electric motor 35 and a fixing member such as the carriage frame 26. Although the illustration is simplified, the lock mechanism 55 mechanically rotates the motor shaft 35a by engaging the engaging member 56 such as a lock pin with the recess 57a of the receiving member 57 fixed to the motor shaft 35a at the time of locking. Stop. On the other hand, when the lock mechanism 55 is released, the engagement between the engagement member 56 and the recess 57a of the receiving member 57 is released as shown in the figure, and the rotation of the motor shaft 35a is allowed. The engaging member 56 is urged by an urging member (not shown) in a direction in which the engagement with the recess 57a is released. At the time of locking, the engaging member 56 is driven against the force of the urging member by an actuator (not shown) and meshes with the recess 57a.

  In this embodiment, such a lock mechanism 55 is provided for at least one auxiliary motor 35. Therefore, when the rotation of the auxiliary motor 35 is locked, the main motor 25 corresponding to the auxiliary motor 35 is controlled via the inverter 40, so that the wheel shaft 23, the wheel 51, etc. corresponding to the locked auxiliary motor 35 are controlled. The torque for driving the rotating member can be controlled. On the other hand, the torque and rotational speed of the remaining wheel shaft 23 and the like to which the auxiliary motor 35 is not locked can be controlled by controlling the auxiliary motor 35 provided thereon. Therefore, since each wheel shaft 23 and wheel 51 can be controlled independently in the same manner as in each embodiment described above, the idling / re-adhesion control described above with the main motor 25 connected in parallel to the common inverter 40, Various motion controls such as vibration control and steering control can be implemented. Since the lock mechanism 55 mechanically locks the rotation of the auxiliary motor 35, the damage to the auxiliary motor 35 is less than that when the auxiliary motor 35 is electrically locked, and the occurrence of electrical loss can be prevented. .

(5th form)
Although the auxiliary motor 35 of each form mentioned above may be an electric motor of any configuration, particularly in the fifth form, each auxiliary motor 35 is configured as an ultrasonic motor. The ultrasonic motor has a feature that can generate a large torque at a low speed and is braked by friction when stopped. Therefore, since the rotation of the auxiliary motor 35 can be easily restricted without power consumption, the same effect as when the lock mechanism 55 as in the fourth embodiment is mounted can be expected.

(Sixth form)
In each form mentioned above, as shown in FIG. 4, control of each main motor 25 is performed via the inverter 40 which these were connected in parallel, and control of each auxiliary motor 35 is provided for every motor. The plurality of auxiliary control units 42 are provided. On the other hand, this embodiment is characterized by the configuration of the control system for the main motor 25 and the auxiliary motor 35. As shown in FIG. 7, in this embodiment, the control system is configured such that two main motors 25 and two auxiliary motors 35 are paired. That is, while the two main motors 25 are connected to the common inverter 60, the two auxiliary motors 35 corresponding to these main motors 25 serve as a common control unit so as to generate torques in opposite directions. The auxiliary control unit 62 is connected in antiparallel. The connection in reverse parallel means that the two auxiliary motors 35 are connected in parallel to the auxiliary control unit 62 in a state where the polarities of the two auxiliary motors 35 are opposite to each other. Therefore, when electric power having the same potential is supplied to the two auxiliary motors 35 via the auxiliary control unit 62, the two auxiliary motors 35 rotate in the opposite directions at the same speed, and the two auxiliary motors 35 Output torques of the same size but in opposite directions. The two main motors 25 are controlled by the main control unit 61 via the inverter 60, and the main control unit 61 corresponds to the main motor control means according to the present invention. Moreover, what includes the auxiliary control unit 62 as a common control unit corresponds to the auxiliary motor control means according to the present invention.

  Since the auxiliary motor 35 is connected in reverse parallel to the common auxiliary control unit 62, by controlling the two auxiliary motors 35 with the auxiliary control unit 62, the two wheel shafts 23 corresponding to these are controlled. The torque difference of the rotating member can be controlled. Thus, the torque of the rotating members such as the two wheel shafts 23 is generated by the common inverter 60 provided for the two main motors 25 and the common auxiliary control unit 62 provided for the two auxiliary motors 25. It becomes possible to control independently. Therefore, as in the above embodiments, the number of auxiliary control units 42 can be reduced for each auxiliary motor 35 (see FIG. 4).

  The present invention is not limited to the above embodiments, and can be implemented in various forms within the scope of the gist of the present invention. The correspondence relationship between the three elements of the planetary gear mechanism and the members such as the main motor and the auxiliary motor connected to the three elements is not limited to the illustrated form, but can be changed to other correspondence relationships. Regarding the number of main motors and auxiliary motors, any number of main motors and auxiliary motors can be used as long as they are plural.

25 main motor 30 planetary gear mechanism 31 sun gear 32 ring gear 33 planet carrier 35 auxiliary motor 40, 60 inverter 41, 61 main control unit (main motor control means)
42, 62 Auxiliary control unit (auxiliary motor control means, common control unit)
55 Locking mechanism

Claims (6)

An electric vehicle drive system applied to an electric vehicle including a plurality of rotating members that are wheel shafts or wheels and a plurality of main motors that are electrically connected in parallel to a common inverter and each drive a separate rotating member. In
A plurality of planetary gear mechanisms each having three elements that rotate differentially with each other, one for each of the main motors;
A plurality of auxiliary electric motors provided one by one for each planetary gear mechanism,
In each of the plurality of planetary gear mechanisms, any one of the plurality of main motors is connected to any one of the three elements, and the plurality of planetary gear mechanisms are connected to any one of the remaining two elements of the three elements. Any one of the rotating members is connected, and any one of the plurality of auxiliary motors is connected to the other two elements of the remaining two of the three elements ,
Auxiliary motor control means for controlling the operating states of the plurality of main motors via the planetary gear mechanism by controlling the plurality of auxiliary motors,
An electric vehicle drive system characterized by that. The plurality of main motors are each configured as a synchronous motor,
Further comprising main motor control means for controlling the plurality of main motors via the inverter ;
It said auxiliary electric motor control means such that said each of the plurality of main motor is operated at the same rotational speed and rotation angle, the electric vehicle drive system according to 請 Motomeko 1 that controls the plurality of auxiliary motor. 2. The electric vehicle drive system according to claim 1, wherein the auxiliary motor control unit indirectly changes the output torque of each of the plurality of main motors by controlling the plurality of auxiliary motors .   The electric vehicle drive system according to any one of claims 1 to 3, further comprising a lock mechanism capable of mechanically locking or releasing rotation of at least one of the plurality of auxiliary electric motors.   The electric vehicle drive system according to any one of claims 1 to 4, wherein each of the plurality of auxiliary motors is configured as an ultrasonic motor. Two main motors are provided as the plurality of main motors,
Two auxiliary motors are provided as the plurality of auxiliary motors,
The electric vehicle drive system according to claim 2, wherein the auxiliary motor control means includes a common control unit in which the two auxiliary motors are connected in antiparallel so as to generate torques in opposite directions.

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