JP3268107B2 - Electric vehicle control device - 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 electric vehicle, and more particularly to an electric vehicle capable of improving the energy efficiency of an engine driving a generator of a series hybrid electric vehicle and reducing vibration and noise. Is provided.

[0002]

2. Description of the Related Art Conventionally, a series type hybrid electric vehicle as shown in FIG. 7 has been proposed. The series-type hybrid electric vehicle includes an engine 1, a generator 2 driven by the engine 1 to generate electric power, a battery 3 charged by electric power generated from the generator 2, a generator 2 or A control unit 4 for converting electric power supplied from the battery 3 or both of them, and a motor 5 for receiving the output of the control unit 4 and running the electric vehicle, wherein the engine drives the generator 2 Dedicated motor 5
Is provided exclusively for running an electric vehicle. FIG.
FIG. 7 is a block diagram showing the series hybrid electric vehicle shown in FIG. In the figure, 1 is an engine which is a generator driving means, 2 is a generator which is driven by the engine 1 and generates electric power, 3 is a battery which is a power storage means charged by electric power generated from the generator 2 and 5 is an electric vehicle Is an inverter which is power conversion means for converting power supplied from the generator 2 or the battery 3 or both, and supplies power to the motor 5. A traveling controller 7 is a traveling controller which receives traveling information from sensors, which are traveling information detecting means (not shown) for detecting traveling information, and controls the inverter 6 to travel the electric vehicle as desired by the driver. , 8
Is a state of charge detector which is a state of charge detecting means for detecting the state of charge of the battery 3, and 9 is a travel controller 7 and a state of charge detector 8
And a power generation unit controller as power generation amount control means for controlling the power generation of the power generation unit including the engine 1 and the power generator 2.

The control device for an electric vehicle configured as described above detects travel information such as the accelerator pedal depression amount and the driving state of the motor 5 (power running, stop or regeneration) by using sensors (not shown), and detects the travel information. The driving controller 7 drives the inverter 6 to drive the electric vehicle as desired by the driver. Since the control technique of the motor 5 is already known, detailed description of the operation is omitted.

Next, the control of the power generation unit will be described with reference to FIG.
This will be described with reference to FIG. In step 41, the remaining capacity of the battery 3 is detected by the remaining capacity detector 8. The remaining capacity can be detected, for example, by setting the full charge of the battery 3 to a zero point, sampling the output of a current sensor for detecting the input / output current of the battery 3 at predetermined time intervals, and integrating the output. In step 42, it is determined whether or not the remaining capacity detected in step 41 is less than 50% of the full charge. Here, if it is 50% or more, it is determined that charging is not necessary, and the process returns to step 41. If it is less than 50%, it is determined that charging is necessary, and the process proceeds to step 43. In step 43, the engine 1 is started, and the warm-up operation is performed for a predetermined time. At this time, the field current of the generator 2 is cut off by the power generation unit controller 9. Therefore, the generator 2 is merely idle and does not generate electric power. In step 44, the driving state (power running, stop or regeneration) of the motor 5 is read from the travel controller 7, and in step 45, it is determined whether the motor 5 is in the regeneration state. If it is in the regenerative state, the process proceeds to step 46 in order to prohibit the power generation of the generator 2 in order to secure the braking force of the electric vehicle. In step 46, the engine 1 is kept at the idling speed, the field current of the generator 2 is kept off, and the process returns to step 44.

Here, the reason why power generation must be prohibited in the regenerative state will be briefly described. When the motor 5 is in the regenerative state, it means that the electric vehicle is in the braking state. The magnitude of the braking force at this time is determined by the amount of power regenerated from the motor 5 to the battery 3 via the inverter 6. By the way, there is a battery having an appropriate charge acceptance value (in other words, an upper limit value of the amount of power that the battery can accept). Therefore, when the generator 2 generates power while the motor 5 is in the regenerative state, the regenerative electric energy of the motor 5 is as shown in Expression (1). Regenerative electric energy = appropriate charge receiving value−generator power generation (1) That is, as understood from the equation (1), when the generator is generating power in the regenerative state, the larger the power generation, the more the motor 5 The amount of regenerative electric power is limited, and the braking force of the electric vehicle is reduced.

If it is determined in step 45 that the motor 5 is not in the regenerative state, there is no fear that the braking force of the electric vehicle will be impaired, so the process proceeds to step 47 to start power generation. In step 47, the rotation speed of the engine 1 is increased to a predetermined rotation speed, and a predetermined field current is supplied to the generator 2. The engine speed is predetermined in accordance with the type of the engine, the displacement, and the like. In step 48, the remaining capacity of the battery 3 is detected as in step 41, and the process proceeds to step 49. In step 49, it is determined whether or not the remaining capacity of the battery 3 is equal to or more than 70%. If it is 70% or more, the process proceeds to step 50, where the engine 1 is stopped and the field current to the generator 2 is cut off, and the process ends.

FIG. 6 is a time chart showing the operation of the generator 2 and the motor 5 when the flowchart of FIG. 5 is executed. As is clear from FIG. 6, when the motor 5 is in the regenerative state, the power generation of the generator 2 is prohibited.

[0008]

As described above, in the conventional control device for an electric vehicle, the engine 1 is set to the no-load idle operation every time the motor 5 enters the regenerative state, so that the energy efficiency of the engine 1 is poor. Was.

When the motor 5 is in a regenerative state, the engine 1 is suddenly changed from a predetermined rotational speed to an idle rotational speed, and when the motor 5 is in a power running state, the engine 1 is suddenly changed from the idle rotational speed to a predetermined rotational speed. And the comfort of the car was impaired.

[0010] The present invention has been made to solve the above-mentioned problems, and is intended to improve the energy efficiency of the engine, suppress vibration and noise from the engine 1, and secure the braking force by regenerating the motor. It is an object of the present invention to obtain an electric vehicle control device capable of improving the performance, improving the charging efficiency of the battery, and extending the life of the battery.

[0011] Further, the present invention is based on driving information.
An object of the present invention is to provide a control device for an electric vehicle that can charge a power storage unit with the most appropriate power generation amount in that state.

Another object of the present invention is to provide a control device for an electric vehicle that can improve the charging efficiency of the power storage means and extend the life by changing the amount of power generation according to the state of the power storage means.

Another object of the present invention is to provide a control device for an electric vehicle that can improve the charging efficiency of the power storage means and extend the life by changing the amount of power generation according to the temperature of the power storage means.

[0014]

SUMMARY OF THE INVENTION A control device for an electric vehicle according to the present invention includes a driving information detecting means for detecting driving information of the electric vehicle, a power storage amount detecting means for detecting a power storage amount of the power storage means, and a driving information. Power generation control means for controlling the generator driving means and the generator based on the output of the stored power detection means, and the power generation control means, when the motor is in a regenerative state, the power generation generated from the generator and The amount of power generation is controlled so that the sum with the amount of regenerative electric power from the motor becomes a predetermined value.

Further, the control device for an electric vehicle according to the present invention includes a correcting means for correcting a predetermined value based on the traveling information.

The control device for an electric vehicle according to the present invention includes a correcting means for correcting a predetermined value substantially in inverse proportion to the information indicating the amount of stored power.

Further, the control device for an electric vehicle according to the present invention includes a correction means for correcting a predetermined value substantially in proportion to information indicating the temperature of the power storage means.

[0018]

When the electric motor is in a regenerative state, the electric vehicle control device of the present invention controls the amount of electric power generation so that the sum of the amount of electric power generated from the generator and the amount of electric power regenerated from the electric motor becomes a predetermined value. .

The control device for an electric vehicle according to the present invention corrects the predetermined value based on the traveling information of the electric vehicle.

Further, the control device for an electric vehicle according to the present invention corrects the predetermined value substantially in inverse proportion to the information indicating the charged amount.

The control device for an electric vehicle according to the present invention corrects the predetermined value substantially in proportion to the information indicating the temperature of the power storage means.

[0022]

【Example】

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Since the block configuration of the first embodiment is the same as that of FIG. 1, the description will be made with reference to this. In the first embodiment, the flowchart in FIG. 2 is used instead of the flowchart in FIG. FIG. 3 is a time chart showing the operation of the generator 2 and the motor 5 according to the flowchart of FIG. Note that the basic operation of the first embodiment is the same as that of the conventional device, and thus the description is omitted here.

First, before giving a detailed description of the first embodiment,
Explain the basic concept. In the above description, when the sum of the amount of regenerative electric power and the amount of power generated by the generator becomes equal to or more than the appropriate charge acceptance value, the battery 3 cannot receive the charge, and the braking force due to regeneration is impaired. When,
Even if the sum of the regenerative electric power and the generator electric power is larger than the appropriate charge receiving value, it can flow into the battery 3. However, in this case, a load is applied to the battery 3 so that the life is shortened, and in the worst case, the battery 3 is damaged. Also, even though the sum of the regenerative power and the generator power exceeds the charge acceptance appropriate value, it can be accepted by the battery, but if the value becomes too large, it cannot be accepted by the battery. As a result, the braking amount due to regeneration is impaired. Therefore, it is most desirable to control the power generation amount of the generator 2 so that the expression (1) is satisfied. Hereinafter, the specific configuration and operation will be described.

In FIG. 2, steps 11, 12, 13
Correspond to steps 41, 42 and 43 in FIG. 5, respectively. In step 11, the state of charge of the battery 3 is detected by the remaining capacity detector 8, and in step 12, it is determined whether or not the charged amount is less than 50% of the full charge. To perform the warm-up operation for a predetermined time at the idle speed. The detection of the charged amount is performed by detecting the remaining amount of the remaining amount of power in the battery 3. However, the consumed amount of the amount of consumed amount of the battery 3 from the full charge is determined. It may be detected.

In step 14, the driving state (power running, stop or regeneration) of the motor 5 is read from the traveling controller 7. In step 15, it is determined whether or not the motor 5 is in a regenerative state based on the information read in step 14. The determination of the regenerative state of the motor 5 may be performed by detecting whether the travel controller 7 instructs the inverter 6 to perform a power running operation, instructs the regenerative operation, or instructs the inverter 6 to stop. If it is determined in step 15 that the motor 5 is in the regenerative state, the process proceeds to step 16. In step 16, the regenerative electric energy is read from the traveling controller 7. Step 1
In step 7, the power generation amount is controlled such that the sum of the regenerative power amount of the motor 5 and the power generation amount of the power generator 2 becomes a predetermined value, which is an appropriate charging acceptance value. In this step, the amount of regenerative electric power read in step 16 is subtracted from the appropriate charge acceptance value of the battery 3 to calculate a power generation amount that does not impair the braking force due to the regeneration of the motor 5. Also, the duty ratio of the field current of the generator 2 corresponding to the generated power is calculated. Note that the appropriate charge acceptance value is determined by the type of battery (for example, lead-acid battery, nickel-cadmium battery, etc.) and its capacity (AH (ampere hour) capacity, which is usually set as a measure of discharge capacity). The size is predetermined according to the size.
In step 18, the control of the duty ratio of the field current obtained in step 17 and the constant speed rotation control for controlling the fluctuation of the engine rotation speed accompanying the fluctuation of the driving torque of the generator 2 to a predetermined rotation speed are performed. It is executed simultaneously by the unit controller 9. In steps 14 to 18, when the motor 5 is in the regenerative state, the control is continued so as to generate the amount of power that does not impair the braking force in accordance with the regenerative electric energy. This is shown in FIG. FIG. 3 shows that when the motor 5 is in a regenerative state, the amount of power generation decreases if the amount of regenerative power increases, and the amount of power generation increases if the amount of regenerative power decreases.

If it is determined in step 15 that the motor 5 is not in the regenerative state, the process proceeds to step 19 in the quantitative power generation mode. Steps 19, 20, 21, and 22 correspond to steps 47, 48, 49, and 50 in FIG. 5, respectively. In these steps, constant power is generated from the generator 2 irrespective of the powering power amount of the motor 5. In step 19, the power generation unit controller 9 performs constant speed rotation control for controlling the rotation speed of the engine 1 to a predetermined rotation speed, and supplies a predetermined field current to the generator 2. Step 2
If 0, the remaining capacity of the battery 3 is detected in the same manner as in step 12. If the remaining capacity is less than 70% in step 21, the process returns to step 14, and if it is 70% or more, the process proceeds to step 22, where the power generation unit controller 9 While the engine 1 is stopped, the field current given to the generator 2 from the power generation unit controller 9 is cut off.

As described above, according to the first embodiment, the amount of power corresponding to the hatched portion in FIG. 3 is increased as compared with the conventional device, and the battery 3 is charged by that much. Therefore, even when the motor 5 is in a regenerative state, the engine 1 is not wasted and the energy efficiency is not deteriorated.

In FIG. 3, the rotation speed of the engine 1 is controlled so as to be always a predetermined rotation speed regardless of whether the motor 5 is in a power running state or a regenerative state. Therefore, the rotational speed of the engine 1 does not suddenly change in accordance with the above, and vibration and noise are suppressed.

Further, since the amount of power generation is increased or decreased in accordance with the amount of regenerative electric power, the braking force due to regeneration of the motor 5 is not impaired.

Further, since the power generation amount of the generator is determined so as to satisfy the equation (1), the battery 3 is charged at an appropriate charge acceptance value, and the charging efficiency of the battery 3 is improved. Since the excessive power does not flow, the life of the battery 3 is not shortened.

Embodiment 2 FIG. In the first embodiment, the battery 3
The charging acceptance appropriate value is uniquely determined by the method and capacity of the battery 3, but this value is corrected based on the driving information of the electric vehicle, so that the energy efficiency of the engine in that state, suppression of vibration noise, safety Performance, battery charging efficiency, and life can be maximized.

As described above, the appropriate value for accepting the charge of the battery is uniquely determined based on the method and capacity. However, the appropriate charge acceptance value varies depending on, for example, the remaining capacity of the battery or the battery temperature. FIG. 4 exemplifies characteristics of a charge acceptance appropriate value with respect to a remaining capacity and a battery temperature in a lead-acid battery. As shown in FIG. 4, the appropriate charge acceptance value of the battery is substantially inversely proportional to the remaining capacity of the battery, and substantially proportional to the battery temperature. By the way, when the electric vehicle is driven, the remaining capacity of the battery depends on the usage conditions at that time (the load condition of the motor 5,
State of electric load such as headlight or air conditioner)
Changes every moment. Further, the battery temperature also changes every moment depending on the use condition of the battery or the ambient temperature of the battery. Therefore, it is desirable to monitor the remaining capacity of the battery and the battery temperature, and correct the appropriate charge acceptance value in accordance with the changes.

In the second embodiment, not only the driving state of the motor 5 but also the remaining capacity of the battery 3 and the temperature of the battery 3 are detected by a sensor (not shown) in step 14 of FIG. In step 17, instead of the reference appropriate charge acceptance value, the appropriate charge acceptance value corrected based on the travel information is used. In the present embodiment, in step 17, a map as shown in FIG. 4 is collated based on the information on the remaining capacity of the battery 3 and the battery temperature obtained in step 14, and an appropriate charge acceptance value is calculated. Note that, in the second embodiment, step 17 includes a correction unit that corrects the appropriate value for accepting charging, which is a predetermined value. The other operations of the second embodiment are the same as those of the first embodiment.

Therefore, according to the second embodiment, the charge acceptance appropriate value is corrected in accordance with the remaining capacity and the temperature of the battery 3, and the regenerative electric energy is subtracted from the corrected value. The battery 3 can be charged with the appropriate charge acceptance value corresponding to the use condition and the battery temperature.

Embodiment 3 FIG. In the above embodiment, the control device of the series-type hybrid electric vehicle has been described. However, the present invention can also be applied to a parallel-type hybrid electric vehicle in which an engine and a motor are used together or selectively used for driving the vehicle. However, in this case, it is necessary to consider that the above control is performed only in a state where the battery is charged by the engine and the electric vehicle is driven by the motor.

Embodiment 4 FIG. In the above embodiment, the combination of the inverter and the AC motor has been described. However, a DC motor driver and a DC motor may be used.

Embodiment 5 FIG. In the above embodiment, the travel information is read from the travel controller 7, but signals from sensors (not shown) may be directly supplied to the power generation unit controller 9. In this case, the driving state of the motor 5 is determined by the power generation unit controller 9.
A method of detecting slip and determining whether the slip is positive or negative. A current in a power supply path (a so-called DC link) from the battery 3 to the inverter 6 flows from the battery 3 toward the inverter 6 or in a reverse direction. A method of determining whether the vehicle is flowing, a method of determining whether the driver has returned the accelerator, and the like can be given.

[0038]

As described above, according to the present invention, when the motor is in the regenerative state, the power generation amount is controlled so that the sum of the power generation amount from the generator and the regenerative power amount from the motor becomes a predetermined value. Therefore, energy efficiency of the engine, suppression of vibration noise, safety, charging efficiency of the power storage means, and life of the power storage means can be improved.

Further, according to the present invention, the predetermined value is corrected based on the ever-changing traveling information.
In this state, the power storage means can be charged with the most appropriate amount of power generation.

Further, according to the present invention, by changing the amount of power generation depending on the state of the power storage means, it is possible to improve the charging efficiency of the power storage means and extend the life.

Further, according to the present invention, by changing the amount of power generation according to the temperature of the power storage means, the charging efficiency of the power storage means can be improved and the life can be extended.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a conventional electric vehicle control device and an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 3 is a time chart showing the operation of the embodiment of the present invention.

FIG. 4 is a characteristic diagram showing characteristics of a proper charge acceptance value with respect to a state of charge and a battery temperature of a lead-acid battery.

FIG. 5 is a flowchart showing the operation of a conventional control device for an electric vehicle.

FIG. 6 is a time chart showing the operation of a conventional control device for an electric vehicle.

FIG. 7 is a configuration diagram showing a general series-type hybrid electric vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Generator 3 Battery 4 Control unit 5 Motor 6 Inverter 7 Travel controller 8 Remaining capacity detector 9 Generator unit controller

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60L 11/00-11/18 G01R 31/36 H02P 9/14 B60K 6/02

Claims (4)

(57) [Claims] 1. A generator which is driven by a generator driving means to generate electric power, an electric storage means charged by electric power generated from the electric generator, and supplied from the electric generator or the electric storage means, or both. Power conversion means for converting power, an electric motor for receiving the output of the power conversion means and running the electric vehicle, travel information detection means for detecting travel information of the electric vehicle, and the power conversion means based on the travel information. Traveling control means for controlling, power storage amount detecting means for detecting the power storage amount of the power storage means, and power generation for controlling the generator driving means and the power generator based on the running information and the output of the power storage amount detecting means. When the electric motor is in a regenerative state, the electric power control means includes a sum of an electric power generated from the electric generator and a regenerated electric energy from the electric motor. A control device for an electric vehicle, wherein the control unit controls the power generation amount so that a predetermined value is obtained. 2. The control device for an electric vehicle according to claim 1, further comprising correction means for correcting a predetermined value based on the travel information. 3. The control device for an electric vehicle according to claim 2, wherein the correction means corrects the predetermined value substantially in inverse proportion to the information indicating the charged amount. 4. The control device for an electric vehicle according to claim 2, wherein the correction means corrects the predetermined value substantially in proportion to information indicating the temperature of the power storage means.