JPH04304102A - Motor vehicle controller - Google Patents

Abstract

PURPOSE:To extend traveling distance per single charging operation and to facilitate accelerator operation at the time of constant speed traveling. CONSTITUTION:The motor vehicle controller comprises a control section 1 performing duty control of conduction voltage of the armature coil 5 in a DC shunt motor 4 in response to an acceleration signal wherein the control section 1 is provided with a switch 3 for switching the control mode between economy mode and power mode. Men the economy mode is set, vehicle speed is calculated based on an output from a vehicle speed sensor 8 and the correlation control characteristics between field current and armature current of the DC shunt motor 4 are switched to those for economy mode in which the armature current value equals to the current value over the entire region of the armature coil 5 corresponding to the calculated speed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle control device, and more particularly to an electric vehicle control device suitable for controlling a DC shunt motor used as a drive motor in an electric vehicle.

0002

[Background Art] Generally, when driving an electric vehicle using a DC shunt motor as the main motor, it is necessary to have characteristics similar to those of a DC series motor and generate large torque during power acceleration. or field current)
Duty control (control using pulse width modulation) is widely practiced. In this case, the armature current must be controlled so that it always has a value proportional to the field current.

By the way, the rotation speed N of the DC shunt motor is:
The torque T of the DC shunt motor is determined by the field current If as shown in FIG. 5, and the armature current Ia as shown in FIG. From these relationships, there is a relationship between the rotation speed N and the torque T as shown by the solid line in FIG. 7, and when traveling at a constant speed V (for example, 40 km/h), the motor rotation speed N1, , the duty control (accelerator work) described later is performed so that the point P1 (torque value T1) at the speed V coincides with the running balance point P (torque value T2) at the rotational speed N1, thereby increasing the driving force (torque). We are matching. Figure 7
The middle dotted line R shows the running resistance curve.

[0004] Duty control of armature current, which determines motor torque, will now be explained with reference to FIGS. 8 to 10. In FIG. 8, an accelerator signal is input to the non-inverting input terminal of the comparator 11, and a reference triangular wave (or sawtooth wave) from a reference wave generating circuit (not shown) is input to the inverting input terminal. In addition, this comparator 11
The output terminal of is connected to the base of a power transistor 12 for drive control of the DC shunt motor, the collector of this power transistor 12 is connected to the positive electrode of the main battery via the armature coil 13, and the emitter is connected to the positive electrode of the main battery. Connected to negative pole. On the other hand, the relationship between the accelerator signal and the accelerator opening is proportional, as shown in Figure 9, so that when the accelerator is fully opened, the accelerator signal is Vx (V), and when the accelerator is fully closed, the accelerator signal is 0 (V). It has become. For example, when the accelerator is half-open, the comparator 11 compares the accelerator signal Vh shown as a in FIG. 10 with a triangular wave, and as a result, the power transistor 12 is controlled at 1/2 duty as shown in b in FIG. The energizing voltage of the armature coil 13 becomes 1/2.

The solid line in FIG. 4 shows the correlation control characteristic I(x) between the armature current Ia and the field current If when the entire energizing voltage is applied to the armature coil 13, and the dashed line shows the correlation control characteristic I(x) when the energizing voltage is applied to the armature coil 13 at a predetermined duty ratio. The correlation control characteristics I(x) of the armature current Ia and the field current If when controlled by are shown respectively. As can be seen from a comparison between FIG. 4 and FIG. (Motor rotation speed N1)
Matching of the driving forces was carried out.

[0006]

[Problem to be Solved by the Invention] As mentioned above, the speed V
(For example, when driving at a constant speed of 40 km/h), since duty control of the armature coil energizing voltage is carried out, chopper loss (controller loss) is involved, and this means that the distance traveled on one charge with the capacity of the installed battery. For electric vehicles that have a fixed battery life, this is a cause of shortening the mileage per charge. Further, when traveling at a constant speed V, an accelerator operation was required for matching the driving force.

[0007]

OBJECTS OF THE INVENTION The present invention has been made in view of the problems of the prior art, and its purpose is to provide an electric vehicle that can extend the driving distance on one charge and also facilitates accelerator operation when driving at a constant speed. The purpose is to provide a control device.

[0008]

[Means for Solving the Problems] The electric vehicle control device of the present invention includes a control unit that duty-controls the energizing voltage of the armature coil of the DC shunt motor in response to an accelerator signal, and the control unit includes a Equipped with a mode selector switch that allows you to change the control mode of the unit to either economy or power mode. The control unit has a first function of calculating the vehicle speed based on the output of the vehicle speed sensor when the mode selector switch is set to economy mode, and correlation control between the field current of the DC shunt motor and the armature current. A second function that switches the characteristic from the correlation control characteristic in the power mode to the correlation control characteristic in the economy mode in which the armature current value is the current value in the entire area of the armature coil corresponding to the calculated speed. have. This configuration attempts to achieve the above-mentioned purpose.

[0009]

[Operation] When the mode selector switch is set to economy mode, the vehicle speed is calculated by the control unit, and the correlation control characteristics of the field current and armature current become the correlation control characteristics in economy mode corresponding to the vehicle speed, and the armature The coil becomes fully conductive controlled.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows the configuration of an electric vehicle control device according to an embodiment of the present invention. In this figure, a controller 1 as a control unit includes an accelerator circuit 2 that outputs an accelerator signal corresponding to the accelerator opening degree, and a mode changeover switch 3 that switches the control mode of the controller 1 to either economy or power mode. , and a vehicle speed sensor 8 are connected. Further, a DC shunt motor 4 is connected to this controller 1, and the DC shunt motor 4
The armature current Ia and field current If flowing through the armature coil 5 and field coil 6, respectively, which constitute the controller 1 are controlled by the controller 1. The armature current Ia is detected by armature current detection means 7 (which is constituted by a shunt resistor) and is fed back to the controller 1. In addition, the armature current Ia is determined by comparing the reference triangular wave and the accelerator signal by the comparator that constitutes the controller 1, and the pulse width of the PWM signal that is the output of this comparator, as explained in the background art section above. Accordingly, the on/off of the power transistor for motor drive control constituting the controller 1 is controlled, and in this way, the energizing voltage of the armature coil 5 is changed by controlling the duty.

[0012] Here, the economy mode and power mode, which are control modes of the controller 1, will be explained. FIG. 2 shows the armature current Ia in both these modes.
The correlation control characteristics between and field current If are shown. In the figure, the solid line is the correlation control characteristic I(x
), the one-dot chain line is the correlation control characteristic I'(x) in the economy mode corresponding to the vehicle speed V1, and the two-dot chain line is the correlation control characteristic I''(x) in the economy mode corresponding to the vehicle speed V2. Power mode is the same control mode as conventional electric vehicles, and economy mode is a control mode when the vehicle speed V is constant and does not require much motor torque.These control modes are: The mode can be switched by the controller 1 according to the setting of the mode changeover switch 3.

Next, the overall operation and effects of this embodiment will be explained. Now, the vehicle speed is V1 (for example, 40 km/h
), when the mode changeover switch 3 is operated while the vehicle is traveling and the economy mode is set, the control mode of the controller 1 is changed from the power mode to the economy mode. That is, the controller 1 calculates the current vehicle speed based on the output of the vehicle speed sensor 8 (first function), and controls the correlation control characteristics between the armature current Ia and field current If of the DC shunt motor 4 in the power mode. The correlation control characteristics during economy mode are changed to correspond to the vehicle speed calculated from the correlation control characteristics during economy mode. As a result, the correlation control characteristic between the armature current Ia and the field current If shown in FIG. 2 changes from I(x) to I'(x
)become. The rotational speed N of the DC shunt motor 4 is determined by the field current If as described above, so if the motor rotational speed at this time is N1, the field current at that time is If1 (see FIG. 5). In addition, the field current If changes from the state satisfying the correlation control characteristic I(x) in FIG.
It is controlled so that it satisfies '(x), so
As a result, the armature current Ia changes from Ia1 to Ia2 in FIG.
The armature current Ia decreases. In other words, the field current If1 at motor rotation speed N1 at speed V1
The balance point between the current Ia and the armature current Ia shifts from point A to point B, and the armature current Ia changes from Ia1 to Ia2. On the other hand, the armature current Ia is determined by the motor torque (see Fig. 6), so as shown in Fig. 3, the speed V
1, the motor torque at point P1 changes from torque T1 at point P1 to torque T2 at running balance point P1', which is the entire conduction region of the energizing voltage of armature coil 5. For this reason,
Duty control of the energizing voltage of the armature coil 5 becomes unnecessary.

Similarly, when the mode selector switch 3 is operated while the vehicle is running at speed V2 and the economy mode is set, the control mode of the controller 1 is changed from the power mode to the economy mode, and the armature current shown in FIG. The correlation control characteristic between Ia and field current If changes from I(x) to I''(x).The motor rotation speed at this time is N2
Then, the field current If is the correlation control characteristic I(x
), the armature current Ia
further decreases (see points B and C in Fig. 2), and as shown in Fig. 3, the motor torque at speed V2 (rotational speed N2) changes from torque T3 at point P2 to running balance point P2.
The torque becomes T4, which is the entire conduction region of the energizing voltage of the armature coil 5. In FIG. 3, the solid line indicates the motor torque-rotation speed characteristic corresponding to the correlation control characteristic I(x) in power mode, and the dotted line indicates the motor torque-speed characteristic corresponding to correlation control characteristic I'(x) in economy mode at vehicle speed V1. The torque-rotational speed characteristic is shown, and the dashed-dotted line shows the motor torque-rotational speed characteristic corresponding to the correlation control characteristic I''(x) in the economy mode at vehicle speed V2, and the curve indicated by symbol R is the running resistance curve. In the above explanation, the correlation control characteristics I'(x) and I''(x) corresponding to the vehicle speeds V1 and V2 were explained as the correlation control characteristics in the economy mode, but in reality, the correlation control characteristics I'(x) and I''(x) corresponding to the vehicle speeds are It is assumed that the correlation control characteristics are stored in an internal memory within the controller 1.

As explained above, according to this embodiment,
When traveling at a constant speed V, by setting the mode changeover switch 3 to economy mode, the controller 1 changes the field current If of the DC shunt motor 4.
Since the correlation control characteristic of the armature current Ia and the armature current Ia is changed from the correlation control characteristic in the power mode to the correlation control characteristic in the economy mode corresponding to the vehicle speed at that time, that is, the entire conduction region of the energizing voltage of the armature coil 5, There is no need to carry out duty control of the energizing voltage of the armature coil 5 of the DC shunt motor 4, it becomes possible to drive with the accelerator fully open, and chopper loss is eliminated, making it possible to extend the mileage per charge. Since it is fully conductive control, all you have to do is press the accelerator fully, making operation easier. In addition, since both economy and power modes can be easily switched by operating the mode changeover switch 3, switching to power mode when accelerating or climbing hills that require motor torque can improve acceleration and
It does not reduce hill-climbing ability, and since the entire conduction area can be used at a constant vehicle speed V, chopper control of the power transistor for motor drive control is not performed, which is advantageous in terms of heat dissipation measures, and there is no chopper noise, so it is quiet. can be run on.

[0016]

Effects of the Invention Since the present invention is constructed and functions as described above, according to this, by setting the mode selector switch to the economy mode, the vehicle speed is calculated by the control section, and the field current and armature The correlation control characteristic of the current becomes the correlation control characteristic in economy mode that corresponds to the vehicle speed, and the armature coil is now controlled to be fully conductive, and the economy control is controlled according to the vehicle speed when set to economy mode by the mode changeover switch. Therefore, when driving at a constant vehicle speed, economy control is possible at any time, and in this respect, the chopper loss of the control section is significantly reduced, making it possible to extend the mileage per charge. It is possible to provide an unprecedented and excellent electric vehicle control device in which the accelerator can be easily operated by simply depressing the accelerator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing correlation control characteristics between armature current Ia and field current If in economy mode and power mode of the controller.

FIG. 3 is a diagram for explaining the operation of the embodiment of FIG. 1;

FIG. 4 is a diagram showing correlation control characteristics between armature current and field current of a DC shunt motor in a conventional example.

FIG. 5 is a diagram showing the relationship between field current and rotation speed of a DC shunt motor.

FIG. 6 is a diagram showing the relationship between torque and armature current of a DC shunt motor.

FIG. 7 is a diagram showing the relationship between motor torque and rotational speed together with a running resistance curve.

FIGS. 8 to 10 are diagrams for explaining duty control of the energizing voltage of the armature coil.

[Explanation of symbols]

1 Controller as a control unit 3 Mode changeover switch 4 DC shunt motor 5 Armature coil 8 Vehicle speed sensor

Claims (1)

[Claims] Claim 1: A control unit that controls the duty of the energizing voltage of the armature coil of the DC shunt motor in response to an accelerator signal, and the control unit is configured to set the control mode of the control unit to either economy or power. A mode changeover switch for switching to the economy mode is provided, and the control unit has a first function of calculating the vehicle speed based on the output of the vehicle speed sensor when the mode changeover switch is set to the economy mode; The correlation control characteristic between the field current and the armature current is set to the economy mode in which the armature current value is the current value in the entire range of the armature coil corresponding to the speed calculated from the correlation control characteristic in the power mode. An electric vehicle control device characterized by having a second function of switching to a time correlation control characteristic.