JP3047621B2 - Control device for engine-driven generator of hybrid 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 control device for an engine-driven generator of a hybrid vehicle, and more particularly to an improvement in a warm-up operation efficiency.

[0002]

2. Description of the Related Art In recent years, attention has been paid to hybrid vehicles having the pollution-free characteristics of electric vehicles and continuous running performance similar to that of engine-driven vehicles. What is important in this hybrid vehicle is to minimize harmful components in exhaust gas when the engine is driven.

[0003] That is, a hybrid vehicle normally drives a motor by electric power from a battery and runs as an electric vehicle. However, when the electric capacity of the battery falls below a predetermined value, the hybrid vehicle drives a generator. Charge the battery. Therefore, exhaust gas from the generator driving engine is inevitably generated. However, an engine for a generator usually operates at a constant load and a constant rotation speed, so that harmful components in exhaust gas at this time can be considerably low.

On the other hand, at the time of starting the engine, due to the low temperature of the engine body and the catalytic converter for purifying exhaust gas, they cannot function sufficiently and the emission of harmful components becomes relatively large. .

Therefore, proposals have been made to reduce harmful components in exhaust gas at the time of starting the engine. For example, in Japanese Patent Application Laid-Open No. 55-157901, when the temperature of the engine is low (cold), the engine speed is increased to accelerate the warm-up of the engine, the warm-up of the engine is accelerated, and the emission of harmful substances is reduced. It has been shown to reduce the amount.

[0006]

However, it is better that the emission of harmful substances is as small as possible. Therefore, it is desired to further warm up the engine and further reduce the emission of harmful substances.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a control apparatus for an engine-driven generator for a hybrid vehicle, which can make the warm-up operation of the engine more efficient and reduce the emission of harmful substances. Aim.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a control system for an engine-driven generator of a hybrid vehicle, which supplies an output of the engine-driven generator to at least one of a battery and a motor when the vehicle runs as an electric vehicle. Temperature detecting means for detecting the temperature of the engine-related parts including the engine body and parts for driving the engine,
Depending on the detection result of the temperature detection means includes a control unit for controlling the engine and generator, and the control unit, before
Engine related parts detected by the serial temperature detecting means
When the temperature is equal to or lower than the set value, the temperature of the engine-related parts is reduced.
Compared with the case where degree exceeds the set value, and controls both the field current of the output and the generator of the engine, along with increasing the output and the rotational speed of the engine, the engine
The output and the number of revolutions are changed and set to a predetermined state in which the efficiency of the engine is lower , and the warm-up operation of the engine is performed.

[0009]

As described above, according to the device of the present invention, when the engine-related parts are at a low temperature, the output of the engine and the field current of the generator are controlled, and not only the output of the engine but also the rotation at that time are controlled. Control the number to a predetermined one. That is, in order to speed up the warm-up of the engine, it is necessary to operate at a point where the energy efficiency of the engine is poor and to increase the amount of heat generation. In order to speed up the warm-up of the catalyst, the exhaust gas has a high temperature. In addition, a predetermined displacement is required. In the present invention, by controlling the engine output and the field current of the generator,
By setting the output and the rotation speed of the engine to predetermined values, the efficiency and the displacement of the engine can be set to predetermined values, and the temperature of the engine and engine-related components such as the catalytic converter can be effectively increased. Thus, the warm-up time of the engine is reduced, and the total amount of harmful substances discharged can be further reduced.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the embodiment. A motor 14 is connected to a battery 10 via an inverter 12, and a DC current output from the battery 10 is converted into an AC current by the inverter 12. Is supplied to the motor 14 and the motor 14 is rotated. As the motor 14, an AC induction motor is usually employed.

The inverter 12 has a plurality of switching elements inside.
It is controlled by the CU 16. That is, the ECU 16
Is the vehicle signal such as the accelerator pedal depression amount and the motor 14
, And generates a PWM (pulse width modulation) signal for driving the motor corresponding to the signal, and controls the switching in the inverter 12.

On the other hand, a generator 22 is connected to the battery 10 via a rectifier 20. The generator 22 is driven by the engine 24. Usually,
The rotation of the engine 24 is increased by the speed increasing gear and supplied to the generator 22. A power generation controller 30 is connected to the generator 22 and an engine controller 32 is connected to the engine 24, and their operations are controlled.
The ECU 16 is connected to the power generation controller 30 and the engine controller 32, and these operations are controlled by the ECU 16. Further, the ECU 1
6, a signal from the SOC meter 34 for detecting the state of charge of the battery 10 is also supplied.
U16 sends a signal to the power generation controller 30 and the engine controller 32 in response to a signal from the SOC meter 34, and controls the field current of the generator 22, the start of the engine 24, and the like.

Further, a temperature sensor 40 and a catalytic converter 42 for removing harmful components are provided in an exhaust gas passage of the engine 24.

Here, the functions of the ECU 16, the power generation control controller 30, and the engine controller 32 will be described together. First, the ECU 16 performs total control of the vehicle. (A) The accelerator opening, the SOC meter 3
4, an output torque command of the motor 14 is generated from the SOC or the like, and thereby the drive control of the motor 14 for controlling the inverter 12; (b) power generation control for performing on / off control of power generation based on the SOC value; Performs engine control to control starting and stopping.

The power generation controller 30 is controlled by the EC
The field current of the generator is controlled so as to enable low-power power generation when the engine 24 reaches the specified rotation by the engine on / off signal from U16. Also, if control becomes impossible or the control range is exceeded, the ECU
Inform 16 of this.

Further, the engine controller 32
From the engine on / off signal from the CU 16 and the starter signal, engine control such as fuel injection amount and throttle circuit adjustment in the engine 24 is performed. In particular, it performs throttle control at the time of engine start, fuel injection amount control, rotation speed increase control, constant power output control at steady time, and the like.

The rating of the motor 14 for driving the vehicle is set based on the acceleration performance. That is, the most demanded output of the vehicle is during acceleration, and the maximum output of the motor is determined from the acceleration performance required of the vehicle. Here, the maximum output of the motor 14 is xkW.

On the other hand, the generator 22 sets a normal running mode and sets an output required for or near the output required for the mode running. Here, let the output of this generator be ykW (for example, several kW). Further, it is assumed that the engine 24 is designed so that the generator 22 has the output of ykW described above. That is, the exhaust amount, the injection amount, and the like are determined according to this.

In such a device, the ECU is normally
16 from the input vehicle signal, P
A WM signal is generated to drive the inverter 12. As a result, the output torque of the motor 14 is made to correspond to the accelerator pedal depression amount and the like, and the vehicle travels according to the command of the driving vehicle.

Next, FIG. 2 shows an example of a change in the SOC in a normal running state. After the start of traveling, while the SOC is sufficiently large, the vehicle travels as an electric vehicle using only the output of the battery. By this traveling, the SOC gradually decreases, and when the SOC becomes a (for example, several tens%) or less (point A), the engine 24 is started, and the alternating current obtained by the The battery is rectified into a direct current, supplied to the battery 10, and charged. Further, the output of the rectifier 20 is also supplied to the power generation controller 30 to perform feedback control of power generation.

Here, such power generation is performed during traveling.
Therefore, the power from the rectifier 20 is also supplied to the inverter 12. The amount of power generated by the generator 22 is set so as to correspond to the average motor drive current during normal running. Therefore, after the start of power generation, the SOC of the battery 10 gradually recovers. When the SOC reaches b (> a) (point B), the driving of the engine 24 is stopped, and the vehicle returns to running as an electric vehicle.

In this example, the SOC meter 34 measures the SOC of the battery 10 by detecting the discharge current of the battery 10 and the voltage at that time (or the charging current and the voltage at that time). This is because the current and the voltage and the SOC have a one-to-one relationship as shown in FIG. 3, and the SOC can be measured by measuring the current and the voltage. This allows the SOC to be configured with a simple configuration
Can be measured.

Here, the control at the time of starting the engine will be described with reference to FIG. First, the SOC is a
If the value falls below the point, the ECU 16 recognizes this from the output from the SOC meter 34 and sends a starter signal to the engine controller 32. Engine controller 3
2 drives, for example, the generator 22 as a starting motor, controls fuel supply to the engine 24, and starts the engine 24 (S1). Then, when the engine starts to rotate, idling with no load at a low rotational speed is performed for a predetermined time. That is, the field current is not supplied to the generator 22 (or the generator 22 is disconnected from the engine 24), the throttle is closed, and the idling state is set (S2), and this is continued until t seconds elapse (S2).
3).

If the idling has continued for t seconds, the output is increased to zkW (for example, several times ykW) (S4). That is, the ECU 16 sends a signal to the engine controller 32 to set the rotation speed of the engine 24 to about twice the normal rotation speed, and sets the field current in the generator 22 to the maximum current amount by the power generation control controller 30.

FIG. 5 shows the output characteristics of such an engine. When t seconds have elapsed from the start of the engine, the throttle opening of the engine is increased and the disclosed current in the generator is increased to increase the engine output. Is controlled to be zkW.

Then, it is determined by the exhaust temperature sensor 40 whether or not the temperature of the engine exhaust has reached a predetermined value (S
5). When this engine exhaust temperature reaches the set value,
It means that the engine temperature and the temperature of the catalytic converter 42 have reached a predetermined value, after which the engine operation should be started with the highest efficiency, and the engine output should be reduced to ykW.
(The number of rotations is one thousand and several hundred, and the field current is several amperes) (S6).

That is, when the engine exhaust temperature reaches the set value as shown in FIG. 5, the engine speed and the field current of the generator are gradually reduced thereafter to reach the set engine output ykW. The rotation speed and field current are used.

In the control for increasing the engine output zkW in S4, as shown in FIG.
P (S41), and when Δt seconds have elapsed (S4
In 2), it is determined whether or not the output is zkW (S43). If the output is not zkW, the process returns to S41, and the output is repeatedly increased. finish. Thus, the output of the engine can be gradually increased. In addition,
The increase in the output ΔP is due to an increase in the field current or an increase in the engine speed. Further, in the same manner as described above, the engine output is reduced by subtracting ΔP in S41,
This is performed by determining at 43 whether the output has reached ykW.

FIG. 7 shows the efficiency of the engine. As described above, the engine 24 is configured so that the rotational speed is _nm and the efficiency η is the best when ykW is output.
Therefore, when the output is set to zkW during the warm-up operation as described above, the rotation speed and the field current change and the output increases, but the efficiency of the engine is poor. However, as a result, the exhaust gas temperature rises, and the temperature rise of the engine 24 and the temperature rise of the catalytic converter 42 can be promoted. In the present embodiment, the engine speed during the warm-up operation is set to be about twice the normal speed. This is because a sufficient amount of exhaust gas can be supplied to the catalytic converter 42 by the amount of exhaust gas specified by the rotation speed. If the engine speed is simply increased, the exhaust gas temperature cannot be sufficiently increased, and the increase in the field current alone cannot make the exhaust capacity appropriate. However, according to the present embodiment, the engine output and the engine speed Since both can be set to predetermined values, the heat generation amount can be set to a predetermined value with the engine efficiency set to a predetermined value, and the exhaust amount can also be set to an appropriate value. Thus, by performing such an operation, the time of the warm-up operation can be reduced, and the total amount of harmful substances discharged can be reduced.

[0030]

As described above, according to the control apparatus for an engine-driven generator for a hybrid vehicle according to the present invention,
At the time of starting the engine, the engine output and the field current to the generator can be controlled so that the engine displacement and the exhaust temperature can be controlled appropriately to perform the warm-up operation. Therefore, the time for the engine warm-up operation can be reduced, and the total amount of harmful gas generated can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a control device for an engine-driven generator of a hybrid vehicle according to the present invention.

FIG. 2 is a characteristic diagram showing an SOC change during traveling.

FIG. 3 is a diagram showing the relationship between SOC and charge / discharge current and voltage.

FIG. 4 is a flowchart illustrating an operation when the engine is started.

FIG. 5 is a diagram showing output characteristics of an engine at the time of starting.

FIG. 6 is a flowchart illustrating an operation of increasing the engine output.

FIG. 7 is a characteristic diagram showing an efficiency according to an engine speed and an output.

[Explanation of symbols]

 Reference Signs List 10 battery 12 inverter 14 motor 16 ECU 24 engine 30 power generation control controller 32 engine controller 40 temperature sensor 42 catalytic converter

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60L 11/02-11/14 F02D 29/06 B60K 9/00

Claims (1)

(57) [Claims] 1. A control device for an engine-driven generator of a hybrid vehicle, which is configured to supply an output of the engine-driven generator to at least one of a battery and a motor when traveling as an electric vehicle, comprising: an engine body and an engine; Temperature detecting means for detecting a temperature of an engine-related component including a part for driving; and a control unit for controlling the engine and the generator in accordance with a detection result of the temperature detecting means, wherein the control unit , if the temperature of the d <br/> engine related parts detected by said temperature detecting means is below a set value, the ene
Compared to when the temperature of the gin-related parts exceeds the set value .
Controlling both engine power and generator field current to increase engine power and speed
In addition, the power and speed of this engine
A control device for an engine-driven generator of a hybrid vehicle, wherein the engine is warmed up by changing and setting the predetermined condition to a lower value.