JP3544116B2 - Drive - Google Patents

Description

[0001]
[Industrial applications]
INDUSTRIAL APPLICABILITY The present invention is a device developed for an electric vehicle, but can be widely used for a device using a motor output as a load. INDUSTRIAL APPLICABILITY The present invention is used as a driving device for a device having a large output load fluctuation. The present invention relates to a drive device that combines two electric motors and performs various controls according to changes in output load.
[0002]
[Prior art]
2. Description of the Related Art A power engine for an automobile requires a large output when the automobile starts or climbs a hill. For this reason, the maximum output of the engine is determined according to the required maximum load. The same is true for electric vehicles. Although the time required for the maximum output is very limited, a large engine must be installed to match the maximum output. This is also true for electric vehicles. Since the structure of the electric motor is simpler than that of the internal combustion engine, two electric motors can be mounted on one automobile.
[0003]
Japanese Patent Application Laid-Open No. 6-189415 discloses a technique for using two electric motors having different characteristics in combination with an electric vehicle. This prior art is a technique in which the mechanical outputs of two electric motors are combined into one and supplied to a load, and the allocation of the two electric motors is changed according to the state of the load. This publication discloses a mechanical circuit that couples the mechanical outputs of two electric motors and supplies them to one load, a mechanical circuit that couples the shafts of two electric motors in series, a mechanism that disconnects and connects the coupling by a clutch, and a drive shaft of each automobile. Discloses a mechanism for providing a drive device for a plurality of electric motors.
[0004]
[Problems to be solved by the invention]
However, in this conventional example, how to select two motors having different characteristics, how to control the load sharing between the two motors, particularly when two motors are mounted on an automobile. There is no disclosure of how to control according to the running of the car. Further, when two electric motors are mounted on an automobile, there is no disclosure of a technique for temporarily using the electric motors as a generator to regenerate electric energy generated by braking.
[0005]
On the other hand, the applicant of the present application manufactures and sells a hybrid vehicle in which an internal combustion engine and an electric motor are combined under the name of HIMR, controls load sharing between the internal combustion engine and the electric motor, temporarily controls the electric motor as a generator, and generates electric power by braking. It has a high technology to regenerate energy that has been converted into electrical energy.
[0006]
The present invention has been made in such a background, and when two electric motors are coupled to one load, particularly when two electric motors are mounted on one automobile to share the load. The purpose of the present invention is to provide a specification of a simple electric motor. An object of the present invention is to provide a control device that smoothly and rationally changes load sharing during operation when the outputs of two electric motors are coupled to one load. The present invention provides an apparatus for temporarily using two electric motors as a generator when the two electric motors are mounted on one automobile, performing braking, and regenerating electric energy generated by the braking to a battery. The purpose is to provide.
[0007]
[Means for Solving the Problems]
The present invention is characterized in that two electric motors appropriately perform various controls including acceleration of an electric vehicle mounted on one vehicle, braking, and regeneration of electric energy generated by braking according to a change in output load. I do.
[0008]
That is, the present invention relates to a driving device including a first motor, a second motor, and a coupling unit that couples outputs of the two motors and supplies the outputs to one load, wherein the first motor is The second motor is for short-time rated high output, and the second motor is for long-time rated small output, and is provided with control means for controlling power distribution between the two motors according to the state of output load. .
[0009]
Each of the two motors is a multi-phase induction motor, and includes a battery provided commonly to the two motors, and two inverters respectively coupling the batteries and the two motors, The means may include means for controlling the frequency of an alternating current supplied to the two motors, using the rotation information of the output of the coupling means, the rotation information of each of the two motors, and the current information of the two motors as inputs. desirable.
[0010]
Further, the two inverters are of a bidirectional type in which electric energy is bidirectionally transmitted between the battery and the two electric motors, respectively, and the control means controls a magnetic field of at least one of the two electric motors. Means for controlling the rotation speed to be smaller than the mechanical rotation speed so as to regenerate mechanical energy on the output side of the coupling means as electric energy to the battery, and means for inputting the temperatures of the two electric motors. Preferably, a clutch is provided between the two electric motors and the coupling means, and the control means includes means for controlling the clutch in conjunction with the power distribution.
[0011]
In the present invention, the entire motor can be downsized by using the first motor for short-time rated high output and the second motor for long-time rated low output. In particular, by mounting such a short-time rated high-output motor and a long-time rated low-output motor on one automobile, the weight of the entire motor can be reduced. That is, in a normal running state of a car, most of the time is in a steady running state, and the output required at this time is about 5 to 20% of the maximum rating. On the other hand, the time required for starting and accelerating is generally very short, and can be 10% or less of the entire engine operating time. Therefore, if two motors are used in combination, a motor with a long-time rating needs only a very small output. A short-time rated motor is sufficient for a high-output motor.
[0012]
On the other hand, electric motors for electric vehicles need to have a wide rotation speed range. Generally, an AC motor has a narrow range of rotation speed at which effective energy can be extracted. However, using a three-phase induction motor, the DC energy obtained from the battery is converted into three-phase AC by an inverter, and this is supplied to the three-phase induction motor, so that the motor can be efficiently operated in a wide rotation speed range. Can work. That is, efficient control can be performed by controlling the slip ratio by controlling the conversion frequency of the inverter by computer and adjusting the three-phase AC frequency to the vicinity of the rotation speed of the motor.
[0013]
That is, when the mechanical rotation speed of the armature is ω ₀ and the electromagnetic rotation speed of the electric motor is ω ₁ , the slip ratio s is
s = (ω ₁ −ω ₀ ) / ω ₁
When the slip ratio s is positive, the three-phase induction machine acts as an electric motor, and when the slip ratio s is negative, the three-phase induction machine acts as a generator. Generally, when the value of the slip ratio s is several percent, the output can be used with high efficiency.
[0014]
Therefore, the mechanical rotation speed ω ₀ of the motor is detected by the rotation sensor, and the electromagnetic rotation speed ω ₁ is controlled based on the output of the rotation sensor, so that the motor output can be output in a wide range of rotation speed. It can be taken out with high efficiency. Further, by controlling the slip ratio according to the information of the mechanical rotation speed ω ₀ , acceleration, deceleration, or cruise speed control can be performed. Further, by controlling the sign of the slip ratio, it can function as a generator and perform regenerative braking.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
[0016]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a main part of an embodiment of the present invention.
[0017]
The embodiment of the present invention includes a first electric motor 1, a second electric motor 2, and coupling means 3 for coupling the outputs of the first electric motor 1 and the second electric motor 2 to supply the output to one load. The first motor 1 is for short-time rated high output, the second motor 2 is for long-time rated low output, and the first motor 1 and the second A control means 4 for controlling the power distribution of the second power supply is provided.
[0018]
A polyphase (three-phase) induction motor is used for each of the first motor 1 and the second motor 2, and a DC high-voltage battery (commonly provided for the first motor 1 and the second motor 2) 300V) 5 and a first inverter 11 and a second inverter 12 for coupling the high-voltage battery 5 with the first motor 1 and the second motor 2 respectively. The control unit 4 receives the rotation information of the output of the coupling unit 3, the rotation information of each of the first electric motor 1 and the second electric motor 2, and the current information of the first electric motor 1 and the second electric motor 2 as inputs. And means for controlling the frequency of alternating current supplied to the first electric motor 1 and the second electric motor 2 (the electromagnetic rotation speed of the electric motor).
[0019]
Here, an example in which the first electric motor 1 and the second electric motor 2 use a three-phase induction motor will be described. However, these are not limited to the induction motor, and the present invention can be widely used using an AC motor.
[0020]
The first inverter 11 and the second inverter 12 are of a bidirectional type in which electric energy is bidirectionally transmitted between the high-voltage battery 5 and the first electric motor 1 and the second electric motor 2, respectively. 4, a high-voltage battery 5 is provided in which at least one of the first electric motor 1 and the second electric motor 2 controls the rotational speed of the magnetic field to be smaller than the mechanical rotational speed so that the mechanical energy on the output side of the coupling means 3 is used as electric energy. And means for inputting the outputs from the temperature sensors 6 and 7 provided in the first electric motor 1 and the second electric motor 2, respectively.
[0021]
Further, a first clutch 21 and a second clutch 22 are provided between the first electric motor 1 and the second electric motor 2 and the coupling means 3, respectively, and the first clutch 21 and the coupling means 3 The second clutch 22 and the coupling means 3 are coupled by a second power shaft 24. The control means 4 includes means for controlling the first clutch 21 and the second clutch 22 in conjunction with the distribution of power to the first electric motor 1 and the second electric motor 2.
[0022]
An output shaft 32 that supplies the output of the first motor 1 and the second motor 2 to the drive wheels 31 via the differential device 30 is directly connected to the coupling means 3. 13 are provided.
[0023]
The first electric motor 1 and the second electric motor 2 are provided with rotational speed sensors 8 and 9, and the first clutch 21 and the second clutch 22 are provided with clutch actuators 14 and 15 for performing a clutch connection / disengagement operation. Be provided. The output shaft 32 is provided with a vehicle speed sensor 16.
[0024]
The high-voltage battery 5 includes a current sensor 17 for detecting a charge / discharge current, and a voltage detection circuit 18 for detecting output voltages of the first inverter 11 and the second inverter 12.
[0025]
FIG. 2 is a diagram showing an example of the internal structure of the connecting means in the embodiment of the present invention. The coupling means 3 includes a first power shaft-side bevel gear 33 directly connected to a first power shaft 23 that transmits the power of the first electric motor 1 via the first clutch 21, A first power shaft side intermediate bevel gear 34 meshed with the shaft side bevel gear 33; a first output shaft side intermediate bevel gear 35 directly connected to the first power shaft side intermediate bevel gear 34; A main bevel gear 36 directly connected to the shaft 32 and meshed with the first output shaft side intermediate bevel gear 35, and a second power shaft for transmitting the power of the second electric motor 2 via the second clutch 22 24, a second power shaft side bevel gear 37 meshed with the second power shaft side bevel gear 37, and a second power shaft side bevel gear 38 meshed with the second power shaft bevel gear 37. A second output shaft side intermediate bevel gear 39 directly connected to the intermediate bevel gear 38 and meshed with the main bevel gear 36; It is.
[0026]
FIG. 3 is a diagram showing an example of output characteristics of the first motor and the second motor in the embodiment of the present invention. The horizontal axis is the rotation speed (N) of the motor, and the vertical axis is the torque (T) of the motor with respect to the rotation speed (N). In the figure, the solid line is the output characteristic of the first motor 1 for short-time rated high output, and the broken line is the output characteristic of the second motor 2 for long-time rated small output. Low speed range of the rotational speed and the boundary value for dividing the high-speed range and N _1, this region below the rotational speed N ₁ is a low speed range, the region exceeding the rotational speed N ₁ is a high rotational speed region.
[0027]
Here, the operation of the embodiment of the present invention will be described. When the control means 4 receives a start operation from an operation switch (not shown), the control means 4 controls the first inverter 11 to convert DC energy stored in the high-voltage battery 5 into three-phase AC, and converts this AC energy into a first electric motor. Supply 1 The first electric motor 1 is rotationally driven as an electric motor by supplying the AC energy.
[0028]
Assuming that the mechanical rotation speed of the armature is ω ₀ and the electromagnetic rotation speed of the electric motor is ω ₁ , the slip ratio s is
s = (ω ₁ −ω ₀ ) / ω ₁
Required by The control means 4 takes in the output of the rotation speed sensor 8, controls so that ω ₁ > ω _0, and makes the slip ratio s positive so that the motor can be rotationally driven.
[0029]
The control means 4 sends a control signal to the clutch actuator 14 in accordance with the rotational drive of the first electric motor 1 to bring the first clutch 21 into the engaged state. Thereby, the driving force of the first electric motor 1 is transmitted from the first power shaft 23 to the coupling means 3.
[0030]
In the coupling means 3, the first power shaft side bevel gear 33 transmits the driving force from the first power shaft 23 to the first power shaft side intermediate bevel gear. Since the first power shaft side intermediate bevel gear 34 is directly connected to the first output shaft side intermediate bevel gear 35, the first output shaft side intermediate bevel gear 35 and the first power shaft side intermediate bevel gear 34 Is transmitted to the main bevel gear 36, and the output shaft 32 is rotationally driven. The driving force transmitted to the output shaft 32 is transmitted to the driving wheels 31 via the differential device 30.
[0031]
At this time, the control means 4 stops the power supply from the second inverter 12 to the second electric motor 2 and puts the second clutch 22 into a disconnected state. As a result, the rotation of the main bevel gear 36 causes the second output shaft side intermediate bevel gear 39, the second power shaft side intermediate bevel gear 38, and the second power shaft side bevel gear 37 to run idle, and the output shaft 32 Has no effect.
[0032]
When the vehicle is running and the vehicle is in the running state, an operation unit (for example, an accelerator pedal) (not shown) is operated to instruct acceleration, and the control unit 4 prepares for the first electric motor 1. It takes the output of the rotation speed sensor 8 that is, the rotational speed if reached high rotational speed region beyond the N ₁ shown in FIG. 3, from the high-pressure battery 5 first controls the first inverter 11 The power supply to the electric motor 1 is cut off, and a control signal is sent to the clutch actuator 14 to put the first clutch 21 into the disconnected state.
[0033]
At the same time, the control means 4 controls the second inverter 12 to convert DC energy stored in the high-voltage battery 5 into AC energy, and supplies this AC energy to the second electric motor 2. Thereby, the second electric motor 2 is rotationally driven as an electric motor. Similarly to the first electric motor 1, the second electric motor 2 rotates as the electric motor by controlling the slip ratio s between the mechanical rotational speed ω ₀ of the armature and the electromagnetic rotational speed ω ₁ of the electric motor to be positive. Drive.
[0034]
The driving force of the second electric motor 2 is transmitted to the second power shaft-side bevel gear 37 directly connected to the second power shaft 24 via the second clutch 22. The power is transmitted to the second power shaft side intermediate bevel gear 38 meshed with the gear 37. Since the second power shaft side intermediate bevel gear 38 and the second output shaft side intermediate bevel gear 39 are directly connected, the transmitted driving force of the second electric motor 2 is transmitted to the second output shaft side intermediate bevel gear. The output shaft 32 is transmitted to the main bevel gear 36 meshed with 39, and the output shaft 32 is rotationally driven. The driving force transmitted to the output shaft 32 is transmitted to the driving wheels 31 via the differential device 30.
[0035]
When the driving force is transmitted by the second electric motor 2, the power supply to the first electric motor 1 is cut off and the first clutch 21 is in the disengaged state. The side intermediate bevel gear 35, the first power shaft side intermediate bevel gear 34, and the first power shaft side bevel gear 33 are in an idling state and do not affect the output shaft 32.
[0036]
The control means 4 takes in the outputs of the rotation speed sensors 8 and 9 and the output of the vehicle speed sensor 16 and monitors whether the vehicle is running in a low rotation speed range or in a high rotation speed range. When the load increases on the uphill and the vehicle shifts from the high rotation speed region to the low rotation speed region, the power supply from the second inverter 12 to the second electric motor 2 is stopped, and the second clutch 22 is disconnected. At the same time, the power supply from the first inverter 11 to the first electric motor 1 is started, and the first clutch 21 is brought into the connected state.
[0037]
By this switching, as shown in FIG. 3, driving by the first electric motor 1 having a large output torque is performed in the low rotation speed range, and the traveling of the vehicle is maintained. When a larger driving force is required, the first inverter 11 and the second inverter 12 are controlled to supply power to the first motor 1 and the second motor 2 and drive the output shaft 32 simultaneously. Empower. This control can be performed by setting a threshold value in the low rotation speed range and programming so that simultaneous driving is performed when the threshold value is exceeded.
[0038]
When the vehicle is running in the high rotation speed range with the second electric motor 2 and the braking means (for example, an electric brake switch) (not shown) is operated to perform braking for deceleration, the control means 4 and controls the second inverter 12 to increase the electromagnetic rotational speed omega ₁ than the second mechanical rotation speed omega ₀ of the armature of the motor 2, to act as a generator and the slip ratio negative. As a result, electric braking is performed and the vehicle is decelerated. The AC energy generated by the electric braking is converted into DC energy by the second inverter 12 and regenerated to the high-voltage battery 5.
[0039]
When the braking operation is performed in a state where the vehicle is traveling by the first motor 1 in the low rotation speed range, the control means 4 similarly controls the first inverter to control the first motor 1 than the mechanical rotation speed omega ₀ of the armature to increase the electromagnetic rotational speed omega _1, to act as a generator and the slip ratio in the negative, the vehicle is decelerated by electric braking. The AC energy generated by the electric braking is converted into DC energy by the first inverter 11 and regenerated to the high-voltage battery 5.
[0040]
Further, the control means 4 takes in outputs of the temperature sensors 6 and 7 of the first electric motor 1 and the second electric motor 2, and monitors an increase in temperature. When the temperature rises above a predetermined value, an alarm is issued from an alarm means (not shown) to urge the user to take action.
[0041]
Thus, a three-phase induction motor is used for the first motor 1 and the second motor 2, the first motor 1 is used for short-time rated high output, and the second motor 2 is used for long-time rated small output. By doing so, the range of the rotational speed is expanded, and it is possible to operate the vehicle efficiently and economically.
[0042]
【The invention's effect】
As described above, according to the present invention, when the outputs of the two electric motors are coupled to one load, it is possible to smoothly and rationally change the load sharing during operation, and to occur during braking. Electric energy can be efficiently regenerated to the battery. Further, the entire motor can be reduced in size, whereby the weight can be reduced and the vehicle can be operated economically.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a main part of an embodiment of the present invention.
FIG. 2 is a diagram showing an example of an internal structure of a coupling unit according to the embodiment of the present invention.
FIG. 3 is a diagram showing an example of output characteristics of a first electric motor and a second electric motor in the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st electric motor 2 2nd electric motor 3 Coupling means 4 Control means 5 High voltage battery 6, 7 Temperature sensor 8, 9 Rotation speed sensor 11 First inverter 12 Second inverter 13 Wheel rotation speed sensor 14, 15 Actuator 16 Vehicle speed sensor 17 Current sensor 18 Voltage detection circuit 21 First clutch 22 Second clutch 23 First power shaft 24 Second power shaft 30 Differential device 31 Drive wheel 32 Output shaft 33 First power shaft side Bevel gear 34 first power shaft side intermediate bevel gear 35 first output shaft side intermediate bevel gear 36 main bevel gear 37 second power shaft side bevel gear 38 second power shaft side intermediate bevel gear 39 second output Shaft side intermediate bevel gear

Claims (2)

A first motor, a second motor, and a driving device including coupling means for coupling the outputs of the two motors and supplying the output to one load,
Each of the two motors is a polyphase induction motor, and includes a battery provided commonly to the two motors, and two inverters respectively coupling the battery and the two motors,
The two inverters are of a bidirectional type in which electric energy is bidirectionally transmitted between the battery and the two electric motors,
The first motor is for short-time rated high output, the second motor is for long-time rated small output, and includes control means for controlling power distribution between the two motors according to the state of output load. ,
The control unit receives the rotation information of the output of the coupling unit, the rotation information of each of the two electric motors and the current information of the two electric motors, and drives only the second electric motor in a high rotational speed range. In the low rotation speed range, the first motor is driven, and the power supply to the two motors is switched when shifting from the high rotation speed range to the low rotation speed range and the low rotation speed range to the high rotation speed range. When the rotation speed falls below a predetermined threshold value in the low-speed rotation range, control is performed to simultaneously drive the two motors, and during braking, the rotation speed of the magnetic field of the second motor is changed to mechanical rotation in the high-speed rotation range. In the low rotational speed range, the rotational speed of the magnetic field of the first electric motor is controlled to be smaller than the mechanical rotational speed to control the mechanical energy on the output side of the coupling means. The containing means for controlling so as to regenerate the battery as electric energy
A drive device characterized by the above-mentioned . 2. The driving device according to claim 1 , further comprising a clutch provided between the two electric motors and the coupling means, wherein the control means includes means for controlling the clutch in conjunction with the power distribution .

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