JP2001028843A - Power generator - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a power generation device capable of improving output and efficiently generating power. SOLUTION: A power generating means having a stator coil 11 for generating power in accordance with rotation of an engine 5, and a booster circuit 20 for boosting and outputting a generated voltage output from the power generating means.
A boost control means for controlling a boost rate of the boost circuit 20 based on a rotation state of the engine 5; and a regulator 30 for adjusting a generated voltage of the power generation means based on an output voltage of the boost circuit 20. I have.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a power generator used for charging a battery, and more particularly to a power generator suitable for charging a battery mounted on a vehicle.

[0002]

2. Description of the Related Art Conventionally, as a power generator mounted on a vehicle, as described in JP-A-58-182434, an AC voltage generated in a power generating coil is full-wave rectified to charge a battery. 2. Description of the Related Art There is known a generator that controls a charging voltage by detecting a charging voltage of a coil and adjusting an exciting current of a coil. This generator aims to improve the output of the generator by boosting the AC voltage generated in the power generation coil by a booster circuit and applying the boosted voltage to a field coil.

[0003]

However, the above-described generator is effective when the rotational speed of the internal combustion engine of the vehicle is low, but is conversely generated when the rotational speed is sufficiently high. The machine becomes a load, and efficient power generation cannot be performed.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a power generation device capable of improving output and efficiently generating power.

[0005]

That is, a power generating apparatus according to the present invention has a power generating means having a power generating coil for generating power as the internal combustion engine is driven, and boosts and outputs a generated voltage output from the power generating means. The booster includes a booster, a boost controller that controls a boost rate of the booster based on a rotation state of the internal combustion engine, and a regulator that adjusts a generated voltage of the power generator based on an output voltage of the booster. .

Further, in the power generation apparatus according to the present invention, the boost control means reduces the boost rate of the boost means with an increase in the rotation speed of the internal combustion engine when the rotation speed of the internal combustion engine exceeds a certain value. It is characterized by making it.

According to these inventions, the provision of the boosting means makes it possible to start power generation when the internal combustion engine is running at a low speed. In addition, when the rotation speed of the internal combustion engine is high, the boosting rate of the boosting means is reduced to suppress excessive power generation, thereby improving power generation efficiency.

The power generating apparatus according to the present invention includes a power generation stopping means for stopping the power generation of the power generating means, and a power generation stop control for causing the power generation stopping means to stop the power generation when the load on the internal combustion engine becomes a predetermined value or more. Means.

Further, the power generation apparatus according to the present invention is characterized in that the boosting control means reduces the boosting rate of the boosting means when the load on the internal combustion engine exceeds a certain value.

[0010] In the power generating apparatus according to the present invention, the boost control means stops boosting of the boost means when the load of the internal combustion engine becomes equal to or more than a predetermined value.

According to these inventions, when the load on the internal combustion engine increases, the boosting of the boosting means is stopped or the power generation is stopped, so that the torque consumption of the internal combustion engine in the power generating device can be reduced. . Therefore, the rotation stability of the internal combustion engine at low rotation can be improved, and engine stall and the like can be effectively prevented.

Further, the power generating apparatus according to the present invention is characterized in that, when power generation of the power generation means is started, output voltage adjustment control means for reducing the function of adjusting the generated voltage of the regulator for a certain period of time from the start is provided. And

According to the present invention, when the power generating means starts power generation, the function of adjusting the generated voltage of the regulator is reduced for a certain period of time from the start, so that the output voltage can be smoothly adjusted by the boosting means. The voltage can be quickly converged to a constant value. For this reason, at the time of starting the power generation by the power generation means, the load fluctuation of the internal combustion engine is suppressed, and the rotation of the internal combustion engine can be stabilized.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

(First Embodiment) FIG. 1 shows a power generator according to the present embodiment. As shown in FIG. 1, a power generation device 1 according to the present embodiment is mounted on a vehicle, and generates power with the driving of an engine 5 to charge a battery 2 of the vehicle. The power generator 1 includes a field coil 10, a stator coil 11, and a rectifier circuit 12 that constitute power generation means.
It has.

The field coil 10 is wound around a rotor (not shown) that rotates with the rotation of the engine 5, and forms a magnetic field around it by passing a current. The stator coil 11 is a power generation coil that is disposed around the rotor and generates power by rotation of the rotor. The rectifier circuit 12 rectifies an AC current generated in the stator coil 11 into a DC current.
A full bridge circuit composed of a to 12f is used. The diodes 12a and 12b, the diodes 12c and 12d, the diodes 12e and 12f are connected in series, the cathodes of the diodes 12a, 12c and 12e are connected as output terminals, and the anodes of the diodes 12b, 12d and 12f are connected. Grounded to earth.

The power generator 1 is provided with a booster circuit 20. The booster circuit 20 is a booster that boosts the output voltage of the rectifier circuit 12. The power generator 1 is provided with a regulator 30. The regulator 30 is an output adjusting unit that adjusts an output voltage of the power generation device 1, and controls an electric current flowing through the field coil 10 in response to an output of the booster circuit 20 to control the generated voltage. That is, when the amount of power generation is large and the output of the booster circuit 20 is large, the current flowing through the field coil 10 is reduced.
The current flowing to 0 is increased so that the output voltage of the booster circuit 20 is controlled to be constant.

A terminal B of the regulator 30 is a power supply terminal of the regulator 30, and is connected to an output side of the booster circuit 20. The F terminal of the regulator 30 is a terminal for drawing a current flowing through the field coil 10,
It is connected to the field coil 10. The E terminal of the regulator 30 is a ground terminal and is grounded.
The L terminal of the regulator 30 is a warning output terminal for giving a warning when an abnormality occurs. The S terminal of the regulator 30 is a terminal for monitoring the output voltage of the battery 2 and is connected to the battery 2. The IG terminal of the regulator 30 is an input terminal that is detected by an ignition switch.

The power generator 1 is provided with an ECU 40. The ECU 40 functions as boost control means for performing boost control of the boost circuit 20.
It is mainly composed of a computer including M and RAM. Various control routines including a boost control routine are stored in the ROM.

The ECU 40 is connected to the battery 2 and receives an output voltage of the battery 2. Also, ECU
Reference numeral 40 is connected to the crank position sensor 51. The crank position sensor 51 functions as engine rotation detecting means for detecting the number of rotations of the engine 5. The ECU 40 is connected to the booster circuit 20 and outputs a booster control signal to the booster circuit 20.
The boosting rate of the boosting circuit 20 is controlled.

FIG. 2 shows a configuration diagram of the booster circuit 20 of the power generator 1.

As shown in FIG. 2, the boosting circuit 20 includes a switching unit 21 and a boosting unit 22. The switching unit 21 outputs an input voltage as a pulse having a constant period by a switching operation. For example, a switching circuit including a power transistor as a switching element is used. The switching frequency and the switching duty ratio of the switching unit 21 are E
It is determined by a control signal output from the CU 40. In this case, by setting the switching duty ratio to 100%, the voltage input to the switching unit 21 is directly applied to the boosting unit 22 and output from the boosting circuit 20 without being boosted by the boosting unit 22. Become.

The booster 22 receives a pulse voltage and boosts the output. For example, a diode is provided in a forward direction from the input side to the output side, and a diode is provided between the output side of the diode and the ground. A circuit in which a capacitor is disposed is used.

Next, the operation of the power generator 1 will be described.

In FIG. 1, when the engine 5 starts,
Accordingly, the rotor around which the field coil 10 is wound rotates, and a rotating magnetic field is formed near the stator coil 11. Due to this change in the magnetic field, a current flows through the stator coil 11, and the current is output to the rectifier circuit 12. The rectifier circuit 12 rectifies the AC current, and outputs the rectified DC current to the booster circuit 20. In the booster circuit 20,
The voltage is boosted based on the control signal of ECU 40, and the boosted DC voltage is output to battery 2. Thereby, charging of the battery 2 is performed.

At this time, the regulator 30 receives the output voltage of the booster circuit 20 and adjusts the current flowing through the field coil 10 so that the voltage becomes constant. For this reason, the output of the power generator 1 is kept constant.

On the other hand, since the booster circuit 20 boosts the output voltage of the rectifier circuit 12, the output voltage of the power generator 1 can be higher than the voltage of the battery 2 even if the rotation speed of the engine 5 is low. Charging becomes possible.

FIG. 3 shows the relationship between the engine speed and the output current in the power generator 1 according to this embodiment. The solid line in FIG. 3 shows the characteristic of the engine speed-output current of the power generator 1 according to the present embodiment, and the broken line shows the characteristic of the engine speed-output current of the power generator (comparative example) without the booster circuit. As shown in FIG. 3, the power generator 1 according to the present embodiment
Can start output at a lower rotation speed to a power generator not having a booster circuit. Therefore, according to the power generator 1 according to the present embodiment, the battery 2 can be charged even when the engine speed is low, and the engine speed during idling can be set low. As a result, the fuel efficiency of the vehicle can be reduced.

On the other hand, as shown in FIG. 3, when the engine speed becomes higher and exceeds a certain speed r1, the power generator (dashed line) having no booster circuit is the power generator 1 according to the present embodiment (broken line). The output is larger than the solid line). This is because, when the engine speed becomes sufficiently high, the booster circuit in the power generator 1 according to the present embodiment causes power loss.

Therefore, in the power generator 1 according to the present embodiment, the boosting rate of the output voltage by
Is controlled based on the number of rotations. That is, as shown in FIG. 4, when the rotation speed exceeds a certain rotation speed r1,
Control is performed so that the boosting rate decreases as the rotational speed increases. In this case, the control of the boosting rate is performed by changing the switching duty ratio in the switching unit 21 of the boosting circuit 20. Thus, the booster circuit 2
By controlling the step-up rate of 0, the output when the rotation speed becomes high can be increased, and the output characteristics of the power generator 1 can be improved.

Further, in the power generator 1 according to this embodiment, if output current detecting means such as a current sensor for detecting the output current of the booster circuit 20 is provided, the output current based on the output current detected by the output current detecting means is provided. By controlling the boosting rate, the boosting rate can be set so that the output current is maximized. In this case, power generation can be performed with optimum efficiency according to the engine speed.

As described above, according to the power generator 1 of the present embodiment, when the engine speed is low, it is possible to increase the boost rate and start power generation at a low speed. On the other hand, when the number of rotations of the engine exceeds a certain number of rotations r1, the boosting rate is reduced to suppress excessive power generation and improve power generation efficiency. Further, by controlling the boosting rate so that the output current of the boosting circuit 20 becomes maximum, power generation can be performed efficiently.

(Second Embodiment) Next, a power generator according to a second embodiment will be described.

The power generator according to the present embodiment has substantially the same structure as the power generator 1 according to the first embodiment shown in FIG. 1, except that a switch 23 serving as power generation stopping means is provided, and the ECU 40 The difference is that the switch 23 is turned on / off and functions as power generation stop control means.

FIG. 5 shows a booster circuit 20 of the power generator 1a according to the present embodiment.

As shown in FIG. 5, in the booster circuit 20, a switch 23 is provided between the switching section 21 and the booster section 22. The switch 23 is on / off controlled by a control signal of the ECU 40. When the switch 23 is on, the pulse voltage output from the switching unit 21 is directly input to the boosting unit 22, and the boosted voltage is output from the boosting circuit 20. On the other hand, switch 2
When 3 is in the off state, the pulse voltage output from the switching unit 21 is not input to the boosting unit 22, the output of the boosting circuit 20 becomes zero, and the power generation stops.

Next, the operation of the power generator 1a will be described.

In FIG. 1, when the engine 5 starts,
A current flows through the stator coil 11, and the current is output to the rectifier circuit 12, rectified by the rectifier circuit 12, and output to the booster circuit 20. In the booster circuit 20, the voltage is boosted based on the control signal of the ECU 40, and the boosted DC voltage is output to the battery 2.

At this time, the step-up rate of the step-up circuit 20 is controlled based on the number of revolutions of the engine 5 as in the power generator 1 according to the first embodiment. On the other hand, when the load of the engine 5 increases to a certain value or more, a process of stopping boosting, stopping power generation, or continuing boosting power generation is performed according to the rotation state of the engine 5.

For example, when the load of the engine 5 is increased to a certain value or more, and the rotation speed of the engine 5 is not less than the power generation start rotation speed r0 and not more than the pressure increase stop rotation speed r2 (see FIG. 4). Then, a control signal is output from the ECU 40 to the switching section 21 of the booster circuit 20, the boosting rate of the booster circuit 20 is set to 0%, and boosting is stopped. In this case, the stop of the boosting reduces the torque of the engine 5 consumed by the power generation device 1a. Therefore, even if the load increases, the rotation state of the engine 5 becomes stable.

When the load of the engine 5 increases to a certain value or more and the rotation speed of the engine 5 is equal to or more than the rotation speed r2, a control signal is output from the ECU 40 to the switch 23 of the booster circuit 20 and the switch is output. 23 is turned off, and the power generation of the power generation device 1a is stopped. In this case, by stopping the power generation, the torque of the engine 5 consumed by the power generation device 1a is reduced. Therefore, the rotation state of the engine 5 when the load increases can be made more stable.

Further, when the load of the engine 5 increases to a certain value or more, if the rotation speed of the engine 5 is the rotation speed r3 which is the rotation speed of the rotation speed r2 or more, the ECU 40 switches the booster circuit 20 The control signal is output to the switch 23, the switch 23 is turned on, and the power generation device 1a performs power generation without boosting. In this case, since the torque of the engine 5 is sufficiently large, power is generated without performing torque control by the power generation device 1a.

According to the power generator 1a, when the load of the engine 5 suddenly increases at a low speed of the engine 5, the boosting of the booster circuit 20 is stopped or the power generator 1a is stopped.
Is stopped, the consumption of the torque of the engine 5 in the power generation device 1a can be reduced. Therefore, the rotation stability at the time of low rotation of the engine 5 can be improved, and engine stall and the like can be effectively prevented.

When the power generation stop control is performed in the power generator 1a, it is desirable to control the on / off state of the switch 23 as follows.

As shown in FIG. 6, when the load on the engine 5 increases, a control signal is output from the ECU 40 to the switch 23, and the switch 23 is turned off for a fixed time.
Thereby, the power generation of the power generation device 1a is stopped only for a certain period of time, and the torque (input torque) consumed by the power generation device 1a is reduced. In this case, the power generation stop time T1 is set according to the time from when the power generation is stopped to when the engine torque starts to increase by the air amount control, for example, 0.20.
It is set to about 1.05 s.

By performing such power generation stop control, the engine torque can be rapidly reduced in response to an increase in the load on the engine 5. Therefore, the engine 5
The engine speed can be effectively prevented from decreasing due to the increase in the load of the engine.

In the power generation stop control, it is desirable to stop the power generation gradually. For example, as shown in FIG.
3, the switch 23 is turned off while the duty ratio of the pulse signal is gradually reduced with time. After a certain period of time has elapsed since the switch 23 was completely turned off, a pulse signal is input to the switch 23 to turn the switch 23 on and off, and the duty ratio of the pulse signal is gradually increased with time. 23 is turned on.

As described above, in the power generation stop control, the switch 23 is gradually switched from the on-state to the off-state or from the off-state to the on-state, whereby a sudden load change of the engine 5 can be avoided, and the timing belt squeal and the like can be avoided. Damage can be prevented. Further, it is possible to prevent a large flyback from being caused by abrupt turning on and off of the switch 23, and to prevent damage to the booster circuit 20 and the like.

(Third Embodiment) Next, a power generator according to a third embodiment will be described.

FIG. 8 shows a power generator according to this embodiment.
The power generator 1b according to the present embodiment has substantially the same configuration as the power generator 1 according to the first embodiment.
The difference is that U40 is connected to the regulator 30 through the wiring 71. Through this wiring 71, EC
A control signal is output from U40 to regulator 30.
In FIG. 8, a load 6 is connected to the positive terminal of the battery 2.

The regulator 30 of the power generator 1b adjusts the output based on the output voltage of the booster circuit 20 so that the output voltage of the power generator 1b falls within a certain range.
An adjustment range changing circuit is provided as output adjustment range changing means for changing the output adjustment range in response to a control signal from the ECU 40. Further, the ECU 40 functions as an output voltage adjustment control unit that changes and controls the output adjustment range.

FIG. 9 shows an example of the adjustment range changing circuit in the regulator 30.

As shown in FIG. 9, the adjustment range changing circuit 31
Is provided in the regulator 30, receives an output voltage of the booster circuit 20, adjusts a current flowing through the field coil 10 via the amplifier 32 based on the output voltage, and
The adjustment range can be changed. The adjustment range changing circuit 31 includes, for example, a comparator (not shown) that determines the output voltage value of the booster circuit 20. In this comparator, two threshold values, an upper limit value and a lower limit value of the allowable range of the output voltage value, are set, and the current flowing through the field coil 10 is reduced when the output voltage value of the booster circuit 20 exceeds the upper limit value. When the output voltage value falls below the lower limit value, the current flowing through the field coil 10 is increased.

The adjustment range changing circuit 31 is provided with the ECU 4
Based on the control signal of 0, the upper threshold value is changed to the high potential side, and the lower threshold value is changed to the low potential side.

FIG. 10 shows a power generator 1b according to the third embodiment.
FIG.

As shown in FIG. 10, when the power generation device 1b stops power generation (power generation state OFF) because the load of the engine 5 exceeds a certain value, the output voltage of the booster circuit 20 decreases and the load on the engine 5 decreases. descend. And the power generator 1b
Restarts power generation (power generation state ON), the output voltage of the booster circuit 20 increases, and the load on the engine 5 also increases.

At this time, a control signal is output from the ECU 40 to the adjustment range changing circuit 31 of the regulator 30 when the power generation is restarted, and the upper limit threshold value V10 of the output voltage becomes higher for a certain time Tx after the power generation is restarted. Threshold V11
And the lower limit threshold V20 is changed to a lower voltage threshold V21.

Thus, at time Tx, the regulator 3
0 expands the allowable range of the output voltage, and the regulator 3
The function of adjusting the generated voltage of 0 is reduced. However, since the output voltage is smoothly adjusted by the booster circuit 20,
Conversely, the output voltage quickly converges to a constant value due to a decrease in the function of the regulator 30 for adjusting the generated voltage. For this reason, load fluctuation of the engine 5 is suppressed, and the rotation of the engine 5 can be stabilized.

On the other hand, as described above, when the upper limit threshold V10 and the lower limit threshold V20 of the adjustment range changing circuit 31 of the regulator 30 are not changed when the power generation is restarted,
As indicated by the broken line in FIG. 10, the engine load and the output voltage periodically fluctuate after the start of power generation and do not converge to a constant value. This is because the power generation adjustment of the regulator 30 cannot be performed quickly, and the power generation adjustment of the regulator 30 and the output adjustment of the booster circuit 20 interfere with each other.

As described above, according to the power generation device 1b according to the present embodiment, when the power generation is started, the power generation adjustment function of the regulator 30 is reduced for a fixed time Tx from the start of the power generation. Voltage adjustment can be performed smoothly, and the output voltage can be quickly converged to a constant value. Therefore, at the start of power generation, the engine 5
Is suppressed, and the rotation of the engine 5 can be stabilized.

[0061]

As described above, according to the present invention, it is possible to start power generation when the internal combustion engine is running at a low speed by providing the boosting means. In addition, when the rotation speed of the internal combustion engine is high, the boosting rate of the boosting means is reduced to suppress excessive power generation, thereby improving power generation efficiency.

Further, when the load on the internal combustion engine is increased, the boosting of the boosting means is stopped or the power generation is stopped, so that the torque consumption of the internal combustion engine in the power generating device can be reduced. Therefore, the rotation stability of the internal combustion engine at low rotation can be improved, and engine stall and the like can be effectively prevented.

Further, when power generation of the power generation means is resumed, the output voltage adjustment function of the regulator is reduced for a certain period of time after the restart, so that the output voltage can be smoothly adjusted by the boosting means, and the power generation voltage is reduced to a constant value. Can be quickly converged. For this reason, when the power generation means restarts power generation, the load fluctuation of the internal combustion engine is suppressed, and the rotation of the internal combustion engine can be stabilized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a power generation device according to a first embodiment.

FIG. 2 is an explanatory diagram of a booster circuit of the power generator according to the first embodiment.

FIG. 3 is an explanatory diagram of a relationship between a rotation speed and an output current in the power generator according to the first embodiment.

FIG. 4 is an explanatory diagram of an operation of the power generation device according to the first embodiment.

FIG. 5 is an explanatory diagram of a booster circuit of a power generator according to a second embodiment.

FIG. 6 is an explanatory diagram of an operation of the power generation device according to the second embodiment.

FIG. 7 is an explanatory diagram of an operation of the power generation device according to the second embodiment.

FIG. 8 is an explanatory diagram of a power generator according to a third embodiment.

FIG. 9 is an explanatory diagram of an output voltage adjustment range changing circuit of the power generator according to the third embodiment.

FIG. 10 is an explanatory diagram of an operation of the power generation device according to the third embodiment.

[Explanation of symbols]

5: engine (internal combustion engine), 11: stator coil (power generation coil), 20: boost circuit, 40: ECU (boost control means).

Continued on the front page F term (reference) 5G060 AA04 CA03 CA13 DB07 DB08 5H590 AA02 AA28 CA07 CA23 CC01 CC18 CC24 CD01 CD10 CE05 DD64 EA01 EB02 EB12 EB14 EB21 EB29 FA01 FA06 FB01 FB03 FC12 FC17 FC22 FC26 GA02 GA06 HA05 HA02 KK01

Claims (6)

[Claims] A power generating means having a power generating coil for generating power in accordance with driving of the internal combustion engine; a boosting means for boosting and outputting a generated voltage output from the power generating means; and a rotation state of the internal combustion engine. A power generation apparatus comprising: a boost control unit that controls a boost rate of the boost unit; and a regulator that adjusts a power generation voltage of the power generation unit based on an output voltage of the boost unit. 2. The method according to claim 1, wherein the step-up control unit decreases a step-up rate of the step-up unit with an increase in the number of revolutions of the internal combustion engine when the number of revolutions of the internal combustion engine exceeds a certain value.
The power generator according to claim 1, characterized in that: 3. A power generation stop means for stopping power generation of the power generation means, and a power generation stop control means for causing the power generation stop means to stop power generation when a load on the internal combustion engine becomes equal to or more than a predetermined value. The power generator according to claim 1, wherein the power generator is provided. 4. The boost control unit according to claim 1, wherein the boost control unit reduces a boost ratio of the boost unit when a load on the internal combustion engine becomes a predetermined value or more. A power generator as described. 5. The pressure increase control means stops the pressure increase of the pressure increase means when the load of the internal combustion engine becomes a predetermined value or more. Power generator. 6. When the power generation means starts power generation,
4. The power generator according to claim 3, further comprising an output voltage adjustment control unit that reduces a function of the regulator to adjust the generated voltage for a predetermined time from the start.