JP3092079B2 - Hybrid electric vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid electric automatic
For vehicles , especially hybrid-type
Ki car .

[0002]

2. Description of the Related Art Recently, electric driving of vehicles has been developed from the viewpoint of environmental problems or energy problems. One type of electric driving is an electric vehicle equipped with an engine and a driving motor (hereinafter referred to as a hybrid electric vehicle). Is known. The hybrid electric vehicle includes a series hybrid system in which a traveling motor is driven by a battery that is charged by a generator driven by an engine and travels,
There is a parallel hybrid system in which part of the driving power is covered by an engine.

For example, JP-A-51-39813 discloses that
A series hybrid electric vehicle is disclosed, in which the output of an engine-driven generator is controlled to be substantially constant to make the load of the engine substantially constant, thereby operating the engine at a constant speed to improve fuel efficiency, The emission is reduced.

[0004]

However, according to the above-mentioned prior art, the engine can be controlled at a constant speed by controlling the constant output of the generator. However, a change in the state of the engine, for example, a change in the temperature of the engine, a change over time, etc. , The output of the engine changes, so that the engine speed when the output of the generator is set to a predetermined value may vary depending on the state of the engine.

[0005] In other words, there is a problem that the engine may not be operated at the optimum fuel efficiency and low emission speed. The present invention has been made in consideration of the above problems, and has as its object to provide a hybrid electric vehicle that can operate an engine at a predetermined rotation speed regardless of the state of the engine.

[0006]

SUMMARY OF THE INVENTION The hybrid type of the present invention
Electric vehicles, as shown in the claim corresponding diagram of Fig. 7, et
And engine, running energy is driven by the engine
A generator that occur power for over conversion, goal electrodeposition the generator
A target power setting means for setting a force, a power calculating means for calculating the electric <br/> force of the generator, the power calculated by the power calculation means, set by the target power setting means and power control means for controlling the power of said generator such that said target power, and engine speed detecting means for detecting a rotational speed of the engine, fuel injection of the engine
And a fuel injection quantity setting means for correcting the amount, the target power setting means, the engine of the engine output times
The target power is set so that the number of revolutions becomes a predetermined number of revolutions.
And the target power deviates from a predetermined range.
Said target power to change to a value within the predetermined range, the
The fuel injection amount setting means is configured to change the target power of the generator.
The previous value is outside the predetermined range and the engine
Range of the target rotation speed range in which the rotation speed of the motor includes the predetermined rotation speed.
If it is outside, the engine speed is set to the target speed.
The fuel injection amount of the engine in the direction of returning to within several ranges
Is corrected .

[0007]

[0008]

The generator is driven by the engine to supply electric power to the electric load. The target power setting means sets the target power, the power calculation means calculates the power of the generator, and the power control means controls the power of the generator so that the power calculated by the power calculation means becomes the target power. .

In particular, in the present invention, the target power setting means sets the engine speed of the engine output to a predetermined speed.
Set the target power so that the target power is
When the power deviates from the predetermined range, the target power is reduced to the predetermined range.
Change to the value in the box. In addition, the fuel injection amount setting means
The value before the change of the target electric power of the electric machine is out of the predetermined range,
And the engine speed is within the target speed range including the predetermined speed.
If the engine speed is out of the range,
Engine fuel injection amount in the direction to return to within the speed range
to correct.

[0010]

As described above, the engine-driven power generator of the present invention restricts the amount of power generated by the generator within a predetermined range so that the engine speed becomes a predetermined speed.
After that, the engine speed reaches the predetermined speed.
Therefore, even if the output of the engine changes due to , for example, a change in the temperature of the engine, a change over time, or the like, the engine speed can always be maintained at the optimum predetermined speed. As a result, the engine can be operated at an optimum fuel efficiency and a low emission speed.

Further, the power generation amount of the generator is outside a predetermined range, even if the state can not be maintained engine speed to a predetermined rotational speed by a power generation amount control, the control of the fuel injection quantity, engine speed Can be maintained at a predetermined rotation speed.

[0012]

EXAMPLES (Reference Example) Reference Example relating to hybrid type electric vehicle according to the present invention shown in the block diagram of FIG. This device comprises a battery 1,
A generator 2 for supplying power to an unillustrated electric load (including a motor for traveling and an electric load for a vehicle) and charging the battery 1, an engine 3 for driving the generator 2, and an auxiliary battery for supplying an exciting current And a DC-D for converting the terminal voltage of the battery 1 to a predetermined DC voltage and charging the auxiliary battery 4
A C converter 5, a current sensor 6 for detecting the output current of the generator 2, and a controller for controlling the power generated by the generator 2.
LA7. Reference numeral 31 denotes a sensor that detects the number of revolutions of the engine 3.

More specifically, the generator 2 which is a three-phase AC generator includes a three-phase armature winding 21 and a three-phase full-wave rectifier for rectifying each generated voltage of the three-phase armature winding 21. 23
And a field coil 22 having one end connected to the higher end of the auxiliary battery 4, and a regulator 24. D is a flywheel diode. The high-order end of the three-phase full-wave rectifier 23 is connected to the high-order end of the battery 1 through the current sensor 6 that detects the output current of the generator 2.
And the lower ends of the batteries 1 and 4 are grounded.

The regulator 24 comprises a power transistor 24a and a comparator 24b for controlling the base voltage of the power transistor 24a. The other end of the field coil 22 is a power source whose emitter is grounded. Transistor 2
4a. Comparator 24b
The control voltage Vs corresponding to the generated power of the generator 2 calculated from the output of the current sensor 6 and the terminal voltage V by the controller 7 is input to the negative input terminal of the controller 24b.
A target voltage Vp corresponding to the target power calculated by the controller 7 is input to the input terminal. Comparator 24b
Compares the voltages Vp and Vs and compares the power transistors 24a
To control the output power of the generator 2 to follow the target power.

The controller 7 includes a microcomputer device 70,
It comprises an A / D converter 71 and a D / A converter 72. The microcomputer device 70 includes an I / O port 73, a CPU
74, a RAM 75, and a ROM 76. More specifically, the A / D converter 71 A / D converts the terminal voltage of the battery 1 and the output current of the generator detected by the current sensor 6 and inputs them to the I / O port 73. The engine speed detected by the sensor 31 is input to the I / O port 73. Further, the CPU calculates the generated power of the generator based on the input battery voltage (generator voltage) and the output current of the generator, and calculates the target power from the engine speed. The D / A converter 72 performs D / A conversion of the target power output from the microcomputer 70 as the target voltage Vp and the control power as the control voltage Vs, and outputs a + voltage input terminal and a − voltage input of the comparator 24b. Typing at the end.

The auxiliary battery 4 for supplying the exciting current is DC-
Since a constant DC voltage is supplied from the battery 1 through the DC converter 5, a constant exciting voltage can be applied to the exciting coil 22. Hereinafter, the control operation of the above device will be described with reference to the flowcharts of FIGS.

First, the microcomputer 70 starts with the input of the power supply voltage, and the microcomputer 70 sets the reference value Vpo as the target voltage Vp which is a voltage corresponding to the target power to be generated by the generator 2 by the comparator 24b, A value higher than the reference value Vpo is output as the corresponding control voltage Vs. As a result, the output voltage of the comparator 24b becomes low level, and the power transistor 24a is turned off. The reference value Vpo is a value corresponding to, for example, a target power of 6 kw. The fuel injection amount F is, for example, a predetermined value 1 when the engine speed at the time of obtaining the target power (6 kW) of the generator 2 is 1
The reference value Fo is set so as to be 600 rpm.

Next, a signal from a hydrometer (not shown) built in the battery 1 is read through the A / D converter 71, and a built-in map is searched based on the read specific gravity to detect the battery capacity (100). Next, it is checked whether the detected battery capacity is equal to or lower than the first level at which charging should be started (102). If the detected battery capacity is equal to or lower than the first level, the engine 3 is started (104). The fuel injection amount F of the engine 3 is set to a predetermined reference value Fo, and the rotation speed N of the engine 3 rises to a predetermined range corresponding to the fuel injection amount.

Next, the number of revolutions N of the engine 3 is read from the sensor 31 (106), and it is checked whether or not the number of revolutions N exceeds the reference number of revolutions No (108). A predetermined value slightly smaller than the reference value Vpo of the target voltage Vp is output as the control voltage Vs to the minus input terminal of the comparator 24b through the / A converter 72 (110).

As a result, the comparator 24b turns on the power transistor 24a, an exciting current flows through the exciting coil 22, and power generation is started. By this power generation, an output current I is supplied from the output terminal of the generator 2 to the battery 1. The output voltage (terminal voltage) of the generator 2 is the sum of the terminal voltage of the battery 1 and the output current I × R (R is the wiring resistance). The output voltage is used, and the internal loss of the generator 2 is corrected later.

On the other hand, at 108, if the rotation speed N is lower than the reference rotation speed No, the control waits until the rotation speed N exceeds the reference rotation speed No. Next, the terminal voltage V of the battery 1 is read,
The output current I of the generator 2 is read from the current sensor 6 (112), and the power of the generator 2 is calculated based on the read V and I (114).

Next, a control voltage Vs corresponding to the average value of the determined power of the generator is determined (116). When the control voltage Vs corresponding to the actual generated power exceeds a predetermined value slightly smaller than the reference of the target voltage Vp, an actual detection value is adopted as the control voltage Vs. As a result, the comparator 24b compares the control voltage Vs with the reference value Vpo of the target voltage Vp, and controls the duty ratio of the power transistor 24a so that they match.

Next, the rotation speed N is inputted (118), and it is checked whether the rotation speed N is within a predetermined range (120). If the rotation speed N is out of the range and the rotation speed N is higher than the reference rotation speed No, the target voltage Vp A predetermined voltage value ΔV is added to the reference value Vpo to increase the generated power to reduce the rotation speed N. Conversely, if the rotation speed N is out of the range and the rotation speed N is lower than the reference rotation speed No, the target voltage Vp A predetermined voltage value ΔV is subtracted from the reference value Vpo to reduce the generated power and increase the rotation speed N (1).
22).

Next, it is checked whether the terminal voltage V of the battery 1 is higher than a predetermined second level (a value higher than the first level by a predetermined value, here, a value corresponding to full charge) (12).
4) If the above is the case, the engine 3 is stopped, and the control voltage Vs is set to the high level to cut off the exciting current.
Return to On the other hand, when the terminal voltage V of the battery 1
If lower than the level. It returns to step 108.

In the above embodiment, both the control voltage Vs, ie, the signal corresponding to the generator power, and the target voltage Vp, ie, the signal corresponding to the target power, are changed to control the generated power. Can also be used. That is, only the target voltage Vp or the control voltage Vs
Only one may be changed. However, these two voltages Vp,
By controlling the generated power using both Vs, the engine speed can be further stabilized.

The target voltage Vp and the control voltage Vs may be set based on the torque corresponding to the power of the generator 2.
In this case, for example, the reference value Vpo of the target voltage Vp is
Assuming that the engine state such as water temperature and air temperature is a predetermined value, a constant coefficient K is applied to the value of the engine generated torque TE when the engine is operating at the predetermined rotation speed No and the generator 2 is generating the target power. May be multiplied by.

On the other hand, the control voltage Vs may be set as follows. That is, the terminal voltage V of the battery 1 is read, the output current I of the generator 2 is read from the current sensor 6, and the load torque (referred to as generator load torque) viewed from the engine 3 side is based on the read V and I. ) The average value TLm of TL is calculated from the following equation. TL = V × I ÷ η + α where η is the efficiency of the generator 2 and the output power (Vp ×
I) / (output power + internal power loss + wiring (battery 1
) Power loss + mechanical loss). Here, η is a constant value.
A search may be performed by storing a three-dimensional map of p, I, and η. Α is a fixed loss. In this embodiment, the generator load torque TL is calculated by calculation, but may be searched from a map stored in the ROM 76. The averaging of the generator load torque TL is performed by software for removing V and I pulsations.

Next, the control voltage Vs is obtained by multiplying the obtained average value TLm of the generator load torque TL by the constant coefficient K. The generator load torque can be calculated from a state signal other than the battery terminal voltage V, the output current I, and the rotation speed N. (Example) real施例hybrid electric vehicle of the present invention will be described with reference to FIG.

This device converts a voltage of the main battery 1, an electric load L such as a motor for driving a vehicle, an auxiliary battery 4 for supplying a field current, and a voltage of the main battery 1 into a DC voltage. 4, a DC-DC converter 5 for charging the battery 4, a generator 2 for charging the main battery 1 and supplying power to the electric load L, an engine 3 for driving the generator 2, and supplying fuel to the engine 3. The fuel injection device 32, the determination of the fuel injection amount, the output and the target value of the output power of the generator 2,
The output engine ECU 8 and the output power of the generator 2 are:
Power control means 9 for controlling the field current of generator 2 so as to be equal to the target output value output from engine ECU 8
And a current detector 6 for detecting a generated current of the generator 2 and an engine EC for detecting a capacity of the main battery 1 to detect a capacity shortage.
U8 includes a capacity detector 10 that outputs a capacity signal S corresponding to the battery capacity. Note that this capacitance detector 1
As 0, a sensor that converts the battery specific gravity into an electric signal as in the first embodiment can be used. 32 is a fuel injection device.

The engine ECU 8 is functionally constituted by a rotational speed detecting means 8a, a fuel injection amount control means 8b, a fuel injection setting means and power control means 8c, and a target power output means 8d. Next, a control flow of the engine ECU 8 will be described with reference to FIGS. When the power of the ECU is turned on, an initial mode (200) is set first, the output power target value P (hereinafter referred to as P) of the generator 5 is set to 0, and a fuel injection amount set value F (hereinafter referred to as F) is set. ) Is set to a fuel injection amount reference value F ₀ (hereinafter referred to as F ₀ ).

Next, the capacity signal S received from the capacity detector 10 is checked to detect the capacity of the main battery 1 (20).
2) If the capacity is not insufficient, the capacity detection is repeated (204), and if it is determined that the capacity is insufficient,
The engine 6 is started (206). Next, the engine speed Ne is detected (208). If Ne is equal to or smaller than the first engine speed set value Ne1, the engine speed detection is repeated (210). If Ne becomes larger than Ne1,
It is determined that the engine has been started, and the initial value P _{0 of the} target electric power generation is set in P (212). When P changes from 0 to P ₀ , this P ₀ is output to the power control means 9 described later, and the power control means 9 causes the generator 2 to generate power at P ₀ .

Next, Ne is detected again (214), and Ne is detected again.
Is the lower limit _NemIN of the target speed and the upper limit N of the target speed.
e _MAX is checked to see if it is within the range. If it is out of the range, proceed to step 232;
Proceed to 8. In step 218, if Ne is exceeded the upper limit value Ne _MAX of the engine rotational speed target value, adding a power correction amount △ P to P (224), further, P is greater than the upper limit P _MAX of the generator power target value Check whether it is (22
6) If not, go to step 232; if it is above, set the value of P _MAX in P, subtract a predetermined fuel injection amount correction value ΔF from F (228), and go to step 232.

On the other hand, if Ne is _{smaller than} the lower limit value Ne _mIN of the engine speed target value in step 218, _ΔP is subtracted from P (220), and P is the generated power target value. It is checked whether the value is below the lower limit P _MIN (222). If not, the process proceeds to step 232. If the value is below the lower limit P _MIN , the value of P _MIN is set to P, and a predetermined fuel injection amount correction value ΔF is added to F. (230), and proceeds to step 232.

At step 232, the value of P is set to P ₀ and the value of F is set to F ₀ in order to store P ₀ and F ₀ after the next engine start (232). In addition,
When the fuel injection amount F is changed in steps 230 and 228, the value of this F is immediately output to the fuel injection device 32,
The fuel injection device 32 performs fuel injection with the new value of F.

Next, the capacity is detected again (234), and the above routine is repeated until the capacity shortage is resolved (236). If the capacity shortage is resolved, the engine is stopped to stop power generation (238). , And return to step 200.
The values of P ₀ and F ₀ are data stored in the backup memory, and are held even when the vehicle is stopped.

That is, the feature of this embodiment is that the engine speed Ne is out of the target speed range Ne _{MIN to} Ne _MAX (216) and the generated power target value P is controlled (220, 224). ), Still out of range (222,
In 226) conditions, and the gist that corrects the fuel injection amount F in a direction to return the engine speed Ne to the range of the target engine speed range Ne _MIN ~Ne _MAX (230,228).

Next, the operation of the power control means 9 will be described. The generated current value detected by the current sensor 6 is converted to a desired voltage value by the power detection unit 9b. The voltage of the main battery 1 is reduced to a desired voltage by the voltage detector 9a.
Each of the voltage signals output from 9a and 9b is integrated by power calculation unit 9d and is exchanged for voltage Vs indicating actual charging power. The voltage Vs is input to the negative input terminal of the comparator 24b, and the positive input terminal of the comparator 24b is applied to the D / A converter 9c to convert the power generation target electric power P output from the engine ECU 8 into an analog voltage. V
p is input. Here, when the actual generated power is larger than the generated power P, the output of the comparator 24b becomes LOW, the field current controlling transistor 24a is turned off, and the field current is cut. Conversely, when the actual generated power is smaller than the generated target power P, the comparator 9e
Becomes HIGH, turns on the transistor 24a, and causes a field current to flow. By the above control, the output power of the generator 2 is controlled to the power generation target power P.

According to the control method of this embodiment, the generator 2
Since the load of the engine 3 becomes constant by the generated power constant control, the engine speed is extremely stabilized, and the fuel injection amount is corrected from the relationship between the actual engine speed and the generated power. Since the output power of the generator 2 can also be controlled to a value within a predetermined range, required power can be reliably supplied.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a reference example.

FIG. 2 is a flowchart showing an example of the control operation of FIG.

FIG. 3 is a flowchart showing an example of the control operation of FIG. 1;

4 is a block diagram showing an actual施例.

FIG. 5 is a flowchart showing an example of the control operation of FIG. 4;

FIG. 6 is a flowchart showing an example of the control operation of FIG. 4;

FIG. 7 is a diagram corresponding to a claim of the embodiment of FIG. 4 ;

FIG. 8 is a diagram corresponding to a claim of the embodiment of FIG. 4;

[Explanation of symbols]

1 battery, 2 a generator, an engine 3, 6 current cell <br/> emissions Sa, 7 controller - la, 24 regulator - motor (power control unit), the rotational speed sensor 31.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshihide Arai 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-63-297744 (JP, A) JP-A-55-81245 (JP, A) JP-A-60-35926 (JP, A) JP-A-4-143429 (JP, A) Patent 2740567 (JP, B2) Patent 2731266 (JP, B2) Patent 2890586 (JP, B2) Hei 5-85739 (JP, B2) Japanese Patent Publication Hei 2-23460 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 6/02 B60L 11/00-11/14 F02D 29 / 06 F02D 29/00-29/06 F02D 41/00-41/40 H02J 7/14-7/32 H02P 9/00-9/48

Claims (1)

(57) [Claims] Calculating a 1. A engine, a generator for generating power for driving the energy conversion is driven by the engine, a target power setting means for setting a target power of the generator, the power of the generator Power calculating means, power control means for controlling the power of the generator so that the power calculated by the power calculating means becomes the target power set by the target power setting means, An engine speed detecting means for detecting a speed of the engine; and a fuel injection amount setting means for correcting a fuel injection amount of the engine. Setting the target power so as to be a number, and changing the target power to a value within the predetermined range when the target power deviates from a predetermined range; The fuel injection amount setting means, when the value of the target power of the generator before the change is out of the predetermined range and the engine speed is out of a target speed range including the predetermined speed. , the hybrid electric vehicles and corrects the fuel injection amount of the engine in the direction of returning to the target rotational speed within the rotational speed of the engine
Moving car .