JP2002218603A - Power generation and charging control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation and charging control device for a vehicle which can make securing of SOC in the secondary battery compatible with the drive performance of the vehicle. SOLUTION: A motor generator 18 generates power by the engine 10 or the kinetic energy of the vehicle and charges a high-voltage battery 32. The motor generator 18 and the high-voltage battery 32 are controlled by a power generation/charging ECU 42. The ECU 42 changes a control mode of the high- voltage battery 32 while controlling an inverter 34, based on the information on the SOC of the battery 32 and the drive status from the engine ECU 46.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for controlling power generation and charging of a vehicle, which controls power generation in accordance with a charged amount of the secondary battery in a system for charging a secondary battery mounted on the vehicle by a generator.

[0002]

2. Description of the Related Art A system for driving a generator by kinetic energy of an engine or a vehicle to charge a secondary battery for power storage is equipped with a secondary battery of a plurality of voltages in addition to a conventional engine-driven vehicle or a hybrid vehicle. It is used in various vehicles such as multiple power supply vehicles. In such a vehicle, when the amount of charge (SOC) of the secondary battery decreases, power generation is performed by the generator to charge the secondary battery.

[0003] In addition, if the above-described power generation is always performed by the generator, the load on the engine increases and the acceleration performance deteriorates. Therefore, during acceleration, the charging of the secondary battery by the generator is stopped and the acceleration performance is reduced. Techniques for maintaining the same have been devised. For example, Japanese Patent Application Laid-Open No. 64-16227 discloses that a negative pressure of an intake pipe downstream of a throttle valve of an engine is detected, and when the negative pressure falls below a certain level, a secondary battery is generated by a generator. A technique for stopping charging has been disclosed.

[0004]

However, in the above prior art, charging of the secondary battery by the generator is always stopped during acceleration without considering the SOC of the secondary battery. When the SOC is low, there is a problem that the SOC further decreases. Also,
There is also a problem that the power generation is restarted as soon as the vehicle is shifted to the normal running after the acceleration, and the running performance is remarkably deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a vehicle capable of ensuring both the SOC of a secondary battery mounted on the vehicle and the traveling performance of the vehicle. It is an object of the present invention to provide a power generation and charging control device.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a power generation and charging control device for a vehicle, wherein the generator generates power by using an engine drive source or kinetic energy of the vehicle, and a power generator. A secondary battery that stores the electric energy generated by the secondary battery, and wherein the traveling state of the vehicle in which the secondary battery is charged by the generator is selected based on the charged amount of the secondary battery. I do.

Further, in the above-described power generation and charging control device for a vehicle, the power generation by the generator is performed based on the charged amount of the secondary battery and the running load of the vehicle.

In the above-described power generation / charge control device for a vehicle, when the amount of stored power of the secondary battery is larger than a predetermined value,
When the running load of the vehicle is smaller than a predetermined amount, power is generated by the generator.

In the above-described power generation and charging control device for a vehicle, the power generation by the generator is performed only by the kinetic energy during deceleration when the charged amount of the secondary battery is close to the full charged amount.

In the above-described power generation and charge control device for a vehicle, there is provided a means for automatically stopping the engine when a predetermined engine stop condition is satisfied, and when the amount of charge of the secondary battery is lower than a predetermined lower limit, the engine is stopped. It is characterized in that automatic stop is prohibited.

[0011]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 shows an example of the configuration of an embodiment of a vehicle power generation and charging control device according to the present invention. 1, a crankshaft 12 of an engine 10 is connected to a crank pulley 16 via a crank pulley clutch 14, and the crank pulley 16 and a motor generator (M / M
G) A belt 26 is stretched between the M / G pulley 20 of 18 and an accessory pulley 24 for driving the accessories 22. In the present embodiment, the motor generator 18 is mounted at the position of a conventional alternator, and connects the crank pulley clutch 14 to generate electric power by the power of the engine 10 via the belt 26. In addition, the start and start of the engine 10 by the motor generator 18 can be performed from the operation stop state of the engine 10. Further, while the engine 10 is stopped, it is also possible to disengage the crank pulley clutch 14 and drive the accessories 22 via the accessory pulley 24 with the belt 26. Further, the motor generator 18 can also regenerate the kinetic energy of the vehicle to generate electric power when the crank pulley clutch 14 is engaged and the vehicle does not depress the accelerator pedal, for example, on a downhill.

The motor generator 18 further includes:
Not only the position of the conventional alternator, but also the engine 10
1 and a torque converter 30 of the automatic transmission 28, and a clutch may be arranged on the left side (engine side) in FIG.

The motor generator 18 is supplied with the DC power of the high-voltage battery 32 converted to AC by the inverter 34 and also with the frequency and the like changed, and the number of revolutions is controlled. In addition, the power generated by motor generator 18 is controlled by inverter 34 and charges high-voltage battery 32. This motor generator 1
8 corresponds to the generator according to the present invention,
2 corresponds to the secondary battery according to the present invention.

A starter 36 of the engine 10, an electric hydraulic pump 31 for supplying oil to the automatic transmission 28, and the like, and a low-voltage battery 38 serving as a power source for ignition systems, meters, ECUs, etc. Is lowered by the DC / DC converter 40 and supplied.

The crank pulley clutch 1 described above
4, motor generator 18, high voltage battery 32, inverter 34, starter 36, low voltage battery 38, DC /
The DC converter 40 is controlled by a power generation and charging ECU 42. The power generation and charging ECU 42 controls the motor generator 1 according to the state of charge (SOC) of the high-voltage battery 32.
8 controls charging through the inverter 34. The SOC of the high-voltage battery 32 generates an output signal of a temperature sensor 44 for detecting the temperature of the high-voltage battery 32, a current sensor 45 for detecting a current flowing into or out of the high-voltage battery 32, and a voltage signal 48 of the high-voltage battery 32. The power is input and calculated by the power generation / charge ECU 42.

The power generation and charging ECU 42 determines that the high SOC state is established when the SOC of the high voltage battery 32 obtained as described above exceeds the reference value Smid for determining whether or not the high SOC is high. to decide. In this case,
Since the high voltage battery 32 is close to the full charge amount and the necessity of charging is low, the motor generator 18 is caused to generate electric power by regenerating the kinetic energy of the vehicle only when the vehicle decelerates, thereby charging the high voltage battery 32. Further, when the SOC of the high-voltage battery 32 is close to the full charge, the power generation of the motor generator 18 can be stopped as needed, or the electric power of the high-voltage battery 32 can be consumed by an electric device mounted on the vehicle.

Next, when the SOC of the high-voltage battery 32 is equal to or less than the reference value Smid and equal to or more than Slow which is the reference value (corresponding to the predetermined value according to the present invention) on the low charge amount side, power generation is performed. It is determined that the charging ECU 42 is in the middle SOC state. In this case, only when the traveling load of the vehicle is smaller than the predetermined amount, the motor generator 18 is caused to generate electric power by the engine drive source or the kinetic energy of the vehicle, and the high-voltage battery 32 is charged via the inverter 34. Thus, for example, when the vehicle is subjected to a large running load equal to or greater than the predetermined amount, such as when the vehicle is accelerating or climbing a hill, power generation is stopped, and a decrease in traveling performance during acceleration, climbing a hill, or the like can be prevented.

Further, when the SOC of the high-voltage battery 32 is equal to or lower than the above Slow, the power generation and charging ECU 42 determines that the state of SOC is low, and the motor generator 18 actively uses the power and kinetic energy of the engine 10 to regenerate. And the high-voltage battery 32 is charged. In this case, a predetermined load for power generation by the motor generator 18 is applied to the engine to charge the high-voltage battery 32. Further, even in a vehicle in which a so-called eco-run mode including means for automatically stopping the engine when a predetermined engine stop condition is satisfied, such as when the vehicle is stopped, the power generation and charging ECU 42 switches the high-voltage battery 32 to the low SOC state. If it is determined that there is, it is preferable that a signal for prohibiting the automatic stop of the engine is output from the power generation and charging ECU 42.

In this case, the prohibition signal is output to an engine ECU 46 that controls the driving of the engine 10.
As shown in FIG. 1, the engine ECU 46 controls a driving of the engine by a water temperature sensor, an idle switch, an accelerator opening sensor, a steering angle sensor, a vehicle speed sensor,
Various signals are input from a throttle opening sensor, a shift position sensor, an engine speed sensor, an air conditioner switch, etc., and an engine throttle valve 49, a fuel injection valve 5
0, control of various auxiliary equipments 22 and the like. Therefore, when the eco-run prohibition signal is output from the power generation and charging ECU 42, the engine ECU 46 prohibits the eco-run mode,
Even if the engine should be automatically stopped if it is normal, such as during a stop of the vehicle, the driving of the engine is continued.

When the SOC of the high-voltage battery 32 falls below a reference value Semg, which is a reference value for determining whether or not the state of emergency is abnormally low, the power generation and charging ECU 42 is in the state of emergency SOC. The inverter 34 is determined to be present, and the inverter 34 is controlled so that the power generated by the motor generator 18 is greater than in the low SOC state.

As described above, the power generation / charge ECU 42 needs to control the motor generator 18 in order to charge the high-voltage battery 32. For this purpose, the temperature of the motor generator 18 is controlled by the temperature sensor 52 and the rotation speed is controlled by the rotation speed. Each signal is detected by the number sensor 54 and each signal is generated and charged EC.
It is configured to input to U42. Information for knowing the running state of the vehicle necessary for power generation and charging control, for example, accelerator opening, throttle opening, vehicle speed, etc., is input from the engine ECU 46.

Since the voltage signal 56 of the low-voltage battery 38 is input to the DC / DC converter 40, when the voltage of the low-voltage battery 38 decreases, the charging of the low-voltage battery 38 from the high-voltage battery 32 is performed by the DC / DC converter. This is performed via the DC converter 40. The control of the DC / DC converter 40 in this case is performed by the power generation and charging ECU 42. In this case, in order to monitor the low voltage battery 38,
The temperature is detected by the temperature sensor 58, and this detection signal is input to the power generation / charge ECU 42.

As described above, in the present embodiment, the high-voltage battery 32 is charged by the motor generator 18 in accordance with the state of the SOC of the high-voltage battery 32 by the power generation and charging ECU 42, so that the SOC becomes too low. Can be prevented. In this case, the charging method is selected in consideration of the traveling state of the vehicle, for example, whether the vehicle is decelerating, traveling at a constant speed, accelerating, or climbing a slope. Performance degradation can also be prevented. In this manner, the motor generator 1 is controlled based on the SOC of the high-voltage battery 32 and the running state (running load) of the vehicle.
Since the power generation is performed by the power generation unit 8, the securing of the SOC of the high-voltage battery 32 and the securing of the traveling performance of the vehicle can both be achieved.

FIG. 2 is a flowchart showing the operation of the power generation and charging control device for the vehicle according to the embodiment shown in FIG. In FIG. 2, the various signals described above are input to the power generation and charging ECU 42, and these signals are processed to calculate the SOC of the high-voltage battery 32 as described above (S
1).

Next, the SOC of the high-voltage battery 32 obtained by the power generation / charge ECU 42 is a reference value S indicating an emergency.
It is determined whether or not the value is greater than emg (S2). If the SOC is less than Semg, the power generation / charge ECU 42 determines the SOC of the high-voltage battery 32 to be the emergency SOC, and sets the power generation control mode to the emergency SOC control mode (S3). ). In the emergency SOC control mode, as described above, the high-voltage battery 3
2 is very low, the engine 10
It is necessary to positively generate electric power by the motor generator 18 by regenerating the motive power and kinetic energy to charge the high-voltage battery 32. In this case, the power generation and charging ECU 42
Controls the inverter 34 to perform a power generation operation near the maximum generated power of the motor generator 18, for example. In this case, in order to avoid a remarkable decrease in running performance, control may be performed so that the opening of the throttle valve is set to be large.

Next, at S2, the SO of the high voltage battery 32
If it is determined that C is equal to or greater than Semg, this S
It is determined whether or not the OC is equal to or less than the low SOC reference value Slow (S4).

If it is determined in S4 that the SOC of the high-voltage battery 32 is equal to or lower than Slow, the power generation and charging ECU 42 determines that the SOC of the high-voltage battery 32 is low, and charges the high-voltage battery 32 in the low SOC control mode. Is performed (S5). In the low SOC control mode, as described above, the motor generator 18 actively generates power by the power of the engine 10 to charge the high-voltage battery 32. However, the output at this time may be a lower value than in the case of the emergency SOC control mode. Therefore, the load for power generation applied to the engine 10 is lower than in the emergency SOC control mode, so that it is possible to avoid a decrease in running performance and fuel efficiency.

In S4, the high voltage battery 32
If it is determined that OC exceeds Slow, this S
It is determined whether or not the OC is equal to or less than the high SOC reference value Smid (S6).

If it is determined in step S6 that the SOC of the high-voltage battery 32 is equal to or less than Smid, the power generation / charge ECU 42 determines that the SOC of the high-voltage battery 32 is medium SOC, and charges the high-voltage battery 32 in the medium SOC control mode. Is performed (S7). In the middle SOC control mode, as described above, the motor generator 1 is powered by the power of the engine 10 or the kinetic energy of the vehicle except when the vehicle is accelerating.
8 to generate power. Further, the generated power in this case can be further reduced as compared with the case of the low SOC control mode, and a decrease in the traveling performance and fuel efficiency of the vehicle can be avoided accordingly. The control of the generated power is performed by controlling the inverter 34 by the power generation and charging ECU 42 as described above.

It is determined whether or not the vehicle is accelerating by generating a vehicle speed signal from a vehicle speed sensor or an accelerator opening signal from an accelerator opening sensor, which is input to the engine ECU 46, and receiving and determining by the charging ECU 42. It can be performed. In this case, when the SOC of the high-voltage battery 32 exceeds Smid, which is the reference value of the high SOC, and approaches the full charge amount during charging, the power generation by the motor generator 18 may be stopped as necessary. Thereby, the power of the engine 10 can be further saved.

Further, if it is determined in S6 that the SOC of the high-voltage battery 32 has exceeded Smid, the SOC of the high-voltage battery 32 is determined to be high by the power generation and charging ECU 42, and charging is performed in the high SOC control mode ( S8). In the high SOC control mode, as described above, the motor generator 18 is driven by the kinetic energy of the vehicle to charge the high-voltage battery 32 only when the vehicle is decelerated. In this case as well, the SO of the high-voltage battery 32
Since C may approach the full charge amount, the power generation by the motor generator 18 may be stopped as necessary.

As described above, the power generation of the vehicle according to the present embodiment
The charging operation of the high-voltage battery 32 by the charging control device is performed.

It is also conceivable that the SOC of the high-voltage battery 32 gradually rises while being charged in the predetermined control mode and exceeds the above-mentioned reference values. In this case, it is also preferable to charge the high-voltage battery 32 while changing the control mode of the high-voltage battery 32 according to the reference value. As a result, it is possible to further reduce the influence on the running performance and fuel efficiency of the vehicle.

Although the above-described power generation and charging control apparatus for a vehicle according to the present invention has been described by taking a parallel hybrid vehicle as an example as shown in FIG. 1, it is not necessarily limited to this. For example, the present invention can be applied to a series hybrid vehicle, a vehicle driven only by a conventional engine, and the like. Further, in the example shown in FIG. 1, a multiple power supply vehicle using a plurality of batteries having different voltages is shown, but the invention is also applicable to a vehicle having only a single battery.

[0036]

As described above, according to the present invention,
Since the charge control mode is changed according to the SOC of the battery, the SOC of the secondary battery can be ensured while ensuring the traveling performance of the vehicle.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a power generation and charge control device for a vehicle according to the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the power generation / charge control device for the vehicle shown in FIG. 1;

[Explanation of symbols]

10 engine, 12 crankshaft, 14 crank pulley clutch, 16 crank pulley, 18 motor generator, 20 M / G pulley, 22 accessories,
24 pulleys for auxiliary machinery, 26 belts, 28 automatic transmission, 30 torque converter, 3
2 High voltage battery, 34 inverter, 36 starter, 38 low voltage battery, 40 DC / DC converter, 42 power generation, charge ECU, 44, 52, 58 temperature sensor, 45 current sensor, 46 engine ECU, 48,
56 voltage signal, 49 throttle valve, 50 fuel injection valve, 54 speed sensor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Hatsuo Nakao 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hidenori Yokoyama 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation F term (reference) 5G060 AA04 AA05 AA08 DB07 DB08 5H115 PC06 PG04 PO02 PU08 PU25 PU26 PV02 PV09 QI03 SE02 TI01 TI02 TO05 TO12 TO13

Claims (5)

[Claims] 1. A generator for generating electric power by an engine drive source or kinetic energy of a vehicle, and a secondary battery for storing electric energy generated by the generator, wherein the secondary battery is generated by the generator. A power generation and charging control device for a vehicle, wherein a traveling state of the vehicle to be charged is selected based on a charged amount of the secondary battery. 2. The power generation and charging control device for a vehicle according to claim 1, wherein the power generation is performed by the generator based on a charged amount of the secondary battery and a running load of the vehicle. , Charge control device. 3. The power generation and charge control device for a vehicle according to claim 1, wherein when the amount of power stored in the secondary battery is larger than a predetermined value, the power generation is performed when a running load of the vehicle is smaller than a predetermined amount. A power generation and charging control device for a vehicle, wherein the power generation is performed by a machine. 4. The power generation and charge control device for a vehicle according to claim 1, wherein when the charged amount of the secondary battery is close to the full charge amount, only the kinetic energy during deceleration is used. A power generation and charging control device for a vehicle, wherein the power generation is performed by the generator. 5. The power generation and charge control device for a vehicle according to claim 1, further comprising: means for automatically stopping an engine when a predetermined engine stop condition is satisfied, wherein A power generation and charging control device for a vehicle, wherein the automatic stop of the engine is prohibited when the charged amount of the battery is lower than a predetermined lower limit.