JP2002233072A - Automobile power source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile power source device small in power consumption without lowering efficiency and not generating the problem such as the deterioration of fuel consumption and lowering of vehicle propulsion force. SOLUTION: The power source device is provided with a magnet generator 1 for generating alternating current, a boosting and rectifying circuit 2 for boosting and rectifying alternating current and outputting direct current, a storage device 3 for storing direct current, a load 4 driven by the direct current, and a control device 5 for controlling the boosting and rectifying circuit. The boosting and rectifying circuit is provided with switching elements S1, S2 and S3 for boosting alternating current generated by the magnet generator. The control device is provided with a rotating speed detection means 7 for detecting the rotating speed of the magnet generator, a storage means 10 for previously storing the duty ratio of the switching element corresponding to the rotating speed, and a boosting control means 13 for reading the duty ratio corresponding to the rotating speed and chopping the switching element by the read duty ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to power generation control of an automobile generator.

[0002]

2. Description of the Related Art The rotational speed of a generator for an automobile rotated by an engine changes every moment according to the rotational speed of the engine. It changes from moment to moment depending on On the other hand, the power required by a load (engine control device or the like) mounted on a vehicle, which is supplied with power from a vehicle generator, also changes momentarily according to the situation at that time.
Therefore, the amount of power generated by the vehicle generator must always be controlled to the amount required at that time.

Conventionally, as the above-mentioned automobile generator, a permanent magnet is provided in a rotor and the amount of generated power is controlled by consuming surplus generated power as heat. Equipped with a device that controls the amount of power generation by controlling the amount of current supplied to the windings, and a rotor that has a stator coil and permanent magnets. With a rotor that controls the amount of power generation and a rotor that has both a rotor coil and a permanent magnet, a magnetic field generated by the magnet and a reverse magnetic field are applied by the rotor coil.
In some cases, the field was weakened to control the amount of power generated.

[0004]

However, the above-mentioned prior art has the following problems. That is, in a generator provided with a permanent magnet in the rotor, the strength of the magnetic field cannot be adjusted, so that the power generation amount cannot be controlled according to the rotation speed of the generator or the power required by the load. Therefore, even when the rotation speed is the lowest and the power generation amount is the lowest, a predetermined voltage, for example, 14 V, is output in advance at the time of idle rotation so that the power generation amount required by the load can be secured. It is necessary to set the strength, that is, the strength of the permanent magnet.

[0005] Then, the amount of power generation increases in proportion to the number of revolutions, so at high speed rotation, for example, at 5000 rpm,
The amount of power generation increases as compared to the time of idling. At this time, if the load mounted on the vehicle does not require this power generation amount, the generated power is left over. When the battery is fully charged with the surplus power generation amount, the battery is overcharged. Therefore, the surplus power generation amount must be discarded as heat. Then, the fuel efficiency deteriorates, the vehicle propulsion (horsepower)
The problem of a decrease in the temperature occurs. In particular, in four-wheeled vehicles,
Since the power consumed by the load mounted on the automobile changes greatly, the power that must be discarded as heat also increases.

Further, by using a generator in which a field winding is wound around a rotor and controlling the amount of current supplied to the field winding, the amount of power generation can be controlled in accordance with the number of rotations and the power required by the load. can do. However, this generator requires a current to flow through the field winding in order to create a field, and therefore consumes extra power and lowers efficiency as compared with the case where a permanent magnet is used. Then, there arises a problem that fuel efficiency deteriorates and vehicle propulsion force (horsepower) decreases.

Further, if a generator having a stator coil and a rotor provided with a permanent magnet is used, a magnetic field generated by the rotor magnet and a reverse magnetic field are applied to the stator coil, and the field is weakened to control the amount of power generation. The amount of power generation can be controlled according to the number and the power required by the load. However, this generator consumes extra power and reduces efficiency because it is necessary to supply current to the stator coil to weaken the field. Then, problems such as further deterioration of fuel efficiency and reduction of vehicle propulsion (horsepower) occur. This generator also has a problem that the control circuit is expensive.

The present invention has been made in order to solve the above-mentioned problems, and has a problem that power consumption is small and efficiency is not reduced, and thus fuel efficiency is deteriorated and vehicle propulsion (horsepower) is reduced. An object of the present invention is to provide a power supply device for a vehicle that does not generate any power.

[0009]

According to a first aspect of the present invention, there is provided a magnet generator (generator 1 in the embodiment) driven by an internal combustion engine (engine 14 in the embodiment) to generate an alternating current, and A step-up rectifier circuit (step-up rectifier circuit 2 in the embodiment) that steps up and rectifies an alternating current generated by a magnet generator and outputs a DC current, and a power storage device that stores the DC current output from the step-up rectifier circuit (the embodiment) Then battery 3)
And a load (load 4 in the embodiment) driven by a DC current supplied from the power storage device or the boost rectifier circuit.
And a control device (the control device 5 in the embodiment) for controlling the step-up rectifier circuit.
The boost rectifier circuit includes a switching element (transistors S1, S2, and S3 in the embodiment) for chopping and boosting an alternating current generated by the magnet generator, and the control device controls a rotation speed of the magnet generator. The rotational speed detecting means (the rotational speed detecting circuit 7 in the embodiment) to be detected and the duty ratio between the ON period and the OFF period at the time of chopping of the switching element corresponding to the rotational speed detected by the rotational speed detecting device are determined in advance. A storage unit (in the embodiment, the storage device 10) that stores the data, and a duty ratio corresponding to the rotation speed detected by the rotation speed detection unit, read from the storage unit, and a booster that chops the switching element with the read duty ratio. A power supply unit for a vehicle, comprising: a control unit (in the embodiment, a boost control and voltage control circuit 13). It is.

According to the above configuration, the alternating current generated by the magnet generator is boosted and rectified by the boost rectifier circuit,
The direct current is converted to a direct current, which is stored in the power storage device and supplied to the load. Then, the rotation speed detecting means detects the rotation speed of the magnet generator, and the boost control means,
A duty ratio corresponding to the rotation speed detected by the rotation speed detection unit is read from the storage unit, and the switching element in the boost rectification circuit is chopped by the read duty ratio to control an output current of the boost rectification circuit. Thus, the output current of the boost rectifier circuit is adjusted within a certain range and supplied to the power storage device and the load regardless of the rotation speed of the magnet generator. Therefore, in the generator, a current adjusted to an appropriate amount of current can be supplied to the power storage device and the load without consuming an extra current for generating a magnetic field, thereby improving charging efficiency. Can be.

According to a second aspect of the present invention, the storage means includes a first duty ratio (output reduction in the embodiment) in which the output current of the step-up rectifier circuit is set according to the number of revolutions and the output current of the step-up rectifier circuit decreases from an initial value. Side Duty table Tbl_B),
A second duty ratio (in the embodiment, an output increasing duty table Tbl_C) at which the output current of the boosting rectifier circuit increases from an initial value, which is set in accordance with the rotation speed, is stored in advance, and the control device includes: A voltage detecting means (a voltage detecting circuit 8 in the embodiment) for detecting a voltage of the power storage device and outputting a detected voltage, and comparing the detected voltage output by the voltage detecting means with a preset reference voltage. As a result of the comparison by the comparing means (the comparing circuit 11 in the embodiment) and the comparing means, if the detected voltage is higher than the reference voltage, the first duty ratio is extracted from the storage means,
2. The vehicle according to claim 1, further comprising: a duty correction unit (in the embodiment, a duty calculation circuit 12) for extracting a second duty ratio from the storage unit when the detection voltage is smaller than the reference voltage. Power supply device.

According to the above arrangement, the comparing means compares the detected voltage output from the voltage detecting means with a predetermined reference voltage, and if the comparison result indicates that the detected voltage is larger than the reference voltage, The correction means retrieves the first duty ratio from the storage means, and if the detected voltage is smaller than the reference voltage, the duty correction means reads the second duty ratio from the storage means.
When the voltage of the power storage device is higher than the reference voltage, the output current of the boost rectifier circuit is reduced, and when the voltage is lower than the reference voltage, the output current of the boost rectifier circuit is increased. . Therefore, the voltage of the power storage device charged by the output current of the boost rectifier circuit is controlled so as to be constantly maintained at a constant level, so that the consumption of surplus power in the generator can be suppressed and the charging efficiency can be improved.

According to a third aspect of the present invention, the storage means stores in advance the duty ratios of a plurality of systems in which the output current of the step-up rectifier circuit decreases or increases from an initial value, which is set according to the number of revolutions. The control device detects a voltage of the power storage device and calculates a deviation between a voltage detection unit that outputs a detection voltage and a detection voltage that is output by the voltage detection unit and a preset reference voltage. 2. The apparatus according to claim 1, further comprising: a deviation calculating unit (a comparison circuit in the embodiment); and a duty correcting unit for extracting a duty ratio for reducing the deviation calculated by the deviation calculating unit from the storage unit. This is an automotive power supply.

According to the above configuration, the deviation calculating means calculates the deviation between the detected voltage output from the voltage detecting means and a preset reference voltage, and the duty correcting means reduces the deviation from the storage means. Extract the duty ratio. Therefore, the duty ratio is changed in the direction of decreasing the deviation, so that the voltage of the power storage device charged by the output current of the boosting rectifier circuit is controlled to be always kept constant, and the power consumption of the generator is reduced. Is suppressed, and the charging efficiency can be improved.

The invention according to claim 4 is characterized in that the storage means stores in advance a duty ratio (in the embodiment, an initial duty table Tbl_A) at which a generated current for each rotation speed becomes a predetermined value or more. An automobile power supply device according to any one of claims 1 to 3. According to the above configuration, the minimum necessary current is always ensured by the automotive auxiliary equipment as a load.

[0016]

FIG. 1 is a configuration diagram showing a configuration of an automobile power supply device according to an embodiment of the present invention. Reference numeral 1 in the drawing denotes a generator having a rotor provided with permanent magnets.
The generator 1 generates three-phase (U-phase, V-phase, and W-phase) AC voltages and currents. This generator 1 has a U-phase output terminal 1U, a V-phase output terminal 1V, and a W-phase output terminal 1W as output terminals.

Reference numeral 2 denotes a step-up rectifier circuit that steps up an AC voltage generated by the generator 1 and converts AC into DC. This step-up rectifier circuit 2 has a U-phase input terminal 2U, a V-phase input terminal 2V, and a W-phase input terminal 2W as input terminals, and a + side output terminal 2P and a − side output terminal as output terminals. 2G, and a U-phase control terminal 2 as a control terminal.
It has a US, a V-phase control terminal 2VS, and a W-phase control terminal 2WS.

The output terminal of the generator 1 is connected to the input terminal of the boost rectifier circuit 2. Specifically, the U-phase output terminal 1U of the generator 1 is connected to the U-phase input terminal 2U of the step-up rectifier circuit 2, the V-phase output terminal 1V is connected to the V-phase input terminal 2V, and the W-phase output terminal 1W Are connected to the W-phase input terminal 2W.

The step-up rectifier circuit 2 includes diodes D1, D2, and D3 for rectification, and field-effect (FET) transistors S1 and S as switching elements for step-up.
2 and S3. Further, the transistor S
Parasitic diodes K1, K2, and K3 are formed between the source and the drain of S1, S2, and S3, respectively. That is, equivalently, the anodes of the parasitic diodes K1, K2, and K3 are connected to the sources of the transistors S1, S2, and S3, respectively, and the drains of the parasitic diodes K1, K2, and K3 are connected to the drains of the transistors S1, S2, and S3, respectively. The cathode is connected. Diode D1, D
The anodes of D2 and D3 are connected to transistors S1 and S1, respectively.
2, connected to the drain of S3.

The U-phase input terminal 2U is connected to the anode of the diode D1, the drain of the transistor S1, and the cathode of the parasitic diode K1. V phase input terminal 2V
Is connected to the anode of the diode D2, the drain of the transistor S2, and the cathode of the parasitic diode K2. The W-phase input terminal 2W is connected to the anode of the diode D3,
The drain of the transistor S3 is connected to the cathode of the parasitic diode K3.

The cathodes of the diodes D1, D2 and D3 are connected to each other, and all of them are connected to the + output terminal 2P. Also, transistors S1, S2, S3
Are connected to each other, and they are all connected to the − side output terminal 2G.

The U-phase control terminal 2US is connected to the gate of the transistor S1, the V-phase control terminal 2VS is connected to the gate of the transistor S2, and the W-phase control terminal 2W
S is connected to the gate of the transistor S3.

Reference numeral 3 denotes a rechargeable battery.
It has a positive terminal 3P and a negative terminal 3G. Reference numeral 4 denotes a load mounted on the vehicle, for example, a control device for controlling the engine of the vehicle, an air conditioner, an illuminator, and the like. The load 4 has a positive input terminal 4P and a negative input terminal 4G. The positive terminal 3P of the battery 3 is connected to the positive input terminal 4P of the load 4, and the negative terminal 3P of the battery 3
G is connected to the negative input terminal 4G of the load 4.

The output terminal of the step-up rectifier circuit 2 is connected to a battery 3
And the input terminal of the load 4. Specifically, the + output terminal 2P of the boost rectifier circuit 2 is connected to the + terminal 3P of the battery 3 and the + input terminal 4P of the load 4, and the − output terminal 2G of the boost rectifier circuit 2 is connected to the battery 3 Of the load 4 and the negative input terminal 4G of the load 4.

Reference numeral 5 denotes a control device for controlling the step-up rectifier circuit 2 according to the rotation speed of the generator 1 or the voltage of the battery 3. The control device 5 includes a voltage (phase) detection circuit 6, a rotation speed detection circuit 7, a voltage detection circuit 8, a reference voltage circuit 9, a storage device 10, a comparison circuit 11, and a duty calculation circuit 1.
2. Built-in boost control and voltage control circuit 13.

The voltage (phase) detection circuit 6 detects a voltage waveform and a phase generated by the generator 1. This voltage (phase) detection circuit 6 is provided with an output of a voltage detector 6a connected between the W-phase output terminal 1W of the generator 1 and the neutral point 1n of the generator 1, and a U-phase output terminal of the generator 1. The output from the voltage detector 6b connected between 1U and the neutral point 1n of the generator 1 is input. The output of the voltage (phase) detection circuit 6 is input to a rotation speed detection circuit 7 and a boost control and voltage control circuit 13.

The rotation speed detection circuit 7 detects the rotation speed of the generator 1 based on the output from the voltage (phase) detection circuit 6 and sends the detection result to the duty calculation circuit 12.

The voltage detection circuit 8 detects a voltage between terminals of the battery 3. The voltage detection circuit 8 sends the detection result of the inter-terminal voltage to the comparison circuit 11. The reference voltage circuit 9 generates a reference voltage for comparison with a voltage between terminals of the battery 3 and sends the reference voltage to the comparison circuit 11.

The storage device 10 has a duty cycle corresponding to the number of rotations.
(Duty) table is stored. D here
The “uty” (duty) is a ratio between an on-period and an off-period of a pulse applied to a control terminal of the boosting rectifier circuit 2 when the boosting rectifier circuit 2 is subjected to PWM control. The output of the storage device 10 is input to the duty operation circuit 12.

The comparison circuit 11 receives the voltage between the terminals of the battery 3 detected by the voltage detection circuit 8 and the reference voltage generated by the reference voltage circuit 9, compares these inputs, and compares the comparison result with the duty calculation circuit. Send to 7b.

The duty operation circuit 12 includes a comparison circuit 11,
The outputs of the rotation speed detection circuit 7 and the storage device 10 are input, the duty is calculated based on these inputs, and the calculation result is sent to the boosting control and voltage control circuit 13.

The boost control circuit 13 includes a duty operation circuit 1
2. The output of the voltage (phase) detection circuit 6 is input, and the boost rectification circuit 2 is controlled based on these inputs. Specifically, the output of the boost control circuit 13 is the U-phase control terminal 2US, the V-phase control terminal 2VS, and the W-phase control terminal 2 of the boost rectifier circuit 2.
Input to WS.

The reason why the output of the voltage (phase) detection circuit 6 is input to the boosting control circuit 13 is that the timing at which the transistors S1, S2, and S3 are turned on and off is detected from the voltage waveform and synchronized with the voltage waveform. This is because the transistors S1, S2, and S3 are turned ON and OFF at the timing when the current is removed.

The reason why the output of the voltage (phase) detection circuit 6 is input to the rotation speed detection circuit 7 is as follows from the voltage waveform.
This is for detecting the rotation speed of the generator 1. That is, since the output of the generator 1 changes according to the number of revolutions, the number of revolutions is detected and reflected on the control of the boost rectifier circuit 2.
The storage device 10 stores a Duty table for each rotation speed, but depending on the rotation speed, increasing the Duty depends on the rotation speed.
The output current sent from the boost rectifier circuit 2 to the battery 3 increases, and the output current sent from the boost rectifier circuit 2 to the battery 3 increases when the duty is reduced. Therefore, it is necessary to detect the rotation speed.

FIG. 2 is a block diagram showing a state in which the power supply device according to the present embodiment is incorporated in an automobile. The engine 14 drives the drive wheels 16 via the transmission 15 and rotates the generator (alternator) 1. The alternating current generated by the generator (alternator) 1 is boosted by the boost rectifier circuit 2, converted into a direct current, and charged in the battery 3. The battery 3 supplies power to a load (auxiliary machine) 4 mounted on the vehicle. The control device 5 controls the boost rectifier circuit 2 according to the rotation speed of the generator (alternator) 1 and the voltage of the battery 3, and controls the amount of charge to the battery 3.

FIG. 3 shows three phases (U-phase,
6 is a timing chart showing the relationship between waveforms (V phase, W phase) and the operations (ON and OFF states) of transistors S1, S2, and S3. In the figure, a synchronous rectification (ON) region, a diode rectification (OFF) region, and a boost control (PWM) region. The switching element of each phase performs a synchronous rectification operation when the potential is lower than the other phases in a region where the boost control is not performed. That is, when the electric potential of the generator 1 is passed through the parasitic diode when the potential of the phase that is not boosted is lower than the other phases,
Turn on the transistor because there is a voltage drop of about 0.5V
Then, the output current is conducted so that the voltage drop does not occur,
Prevents voltage loss. Between the boost control region and the synchronous rectification region, since the other phases are performing synchronous rectification,
At this time, if the transistor is turned on at the same time to perform synchronous rectification, a short circuit occurs with another phase that is performing synchronous rectification, and a loss occurs. Therefore, in order to prevent a short circuit, the output current of the generator 1 is reduced. , Through a parasitic diode.

FIG. 4 is a diagram showing the operation of the transistors S1, S2 and S3 during the period T1 shown in FIG. During this period T1, the transistor S1 controls the boost (PW
M) region, the transistor S2 is also in the boost control (PWM) region, and the transistor S3 is in the synchronous rectification (ON) region. During this period T1, the output current of the generator 1 (arrow i1)
Through the parasitic diode K3 connected in parallel with the transistor S3, a voltage drop of about 0.5 V occurs in the parasitic diode K3.
Is turned on to prevent voltage loss. Note that arrows i1 and i2 in the figure indicate the directions of the output current of the generator 1.

FIG. 5 is a diagram showing the operation of the transistors S1, S2 and S3 during the period T2 shown in FIG. In this period T2, the transistor S1 is in a diode rectification (OFF) region, and the transistor S2 is in a step-up control (PW
M) region, the transistor S3 is in the synchronous rectification (ON) region. Note that arrows i2 and i3 in the figure indicate the directions of the output current of the generator 1.

FIG. 6 shows the timing chart shown in FIG. 3 in which the transistors S1, S2 and S3 are turned on and off.
6 is a timing chart showing F. Boost control (P
In the WM) region, ON and OFF of the transistor are repeated. The ratio between the ON time and the OFF time in this area is called a duty ratio (Duty ratio).

FIG. 7 is a graph showing the relationship between the number of revolutions of the generator 1 and the output current output from the boost rectifier circuit 2 at each duty. This graph shows that when the duty is increased, the output current increases depending on the rotation speed,
This indicates that lowering the duty may increase the output current.

Referring to this figure, Du in the present embodiment is shown.
The method of changing ty will be described with a specific example. First, in order to suppress the output current of the boost rectifier circuit 2 when the rotation speed is 2000 rpm and the duty is 40%, Dut
In order to increase y to 80% and to increase the output current of the boost rectifier circuit 2, Duty is reduced to 20%. This means that the duty is 20% at this rotational speed.
The output current of the boost rectifier circuit 2 becomes maximum,
This is because when Duty is set to 80%, the output current of the boost rectifier circuit 2 becomes minimum.

When the number of rotations is 2500 to 4500 rpm, the output of the boosting rectifier circuit 2 may decrease even if the duty is increased or decreased. For example, considering that the output current of the step-up rectifier circuit 2 is suppressed when the rotation speed is 3000 rpm and the duty is 40%, the duty is set to 20% or 60% in either case. Also, the output current of the boost rectifier circuit 2 decreases. In such a case, an efficient duty of 60% shown in FIG. 8 described later is selected.

The rotation speed is 5000 rpm and the duty is 40
%, The duty is reduced to 20% in order to suppress the output current of the boost rectifier circuit 2, and to increase the output current of the boost rectifier circuit 2, the duty is increased to 80%. I do. This is because at this rotational speed Du
This is because when ty is set to 20%, the output current of the boost rectifier circuit 2 becomes minimum, and when Duty is set to 80%, the output current of the boost rectifier circuit 2 becomes maximum.

FIG. 8 is a graph showing the relationship between the rotation speed of the generator 1 and the efficiency of the boost rectifier circuit 2 at each duty. According to this graph, the higher the duty, the higher the efficiency.

FIG. 9 is a flowchart showing the operation of the present embodiment. Hereinafter, the operation of the present embodiment will be described with reference to this flowchart.
Reference numerals 1 to ST15 represent steps in the flowchart. First, when the ignition key is turned on, 0 is set as an initial value in a region where the rotation speed Nb used for comparison is held. In other words, 0 is substituted for Nb (ST1).

Next, the voltage (phase) detection circuit 6 detects the phase of the output waveform of the generator 1 (ST2), and the rotation speed detection circuit 7 determines the rotation speed Na of the generator 1 from the output waveform. Detect (ST3). Then, the detected rotation speed Na is
It is checked whether or not it is greater than a predetermined value, that is, whether or not the idling speed has been reached. If it is not larger than the predetermined value (N), it is determined that the engine is stopped, the boost control is stopped (ST5), and the process returns to step ST1.
When the detected rotation speed Na is larger than a predetermined value (Y)
Is determined that the engine has started, and the next step S
Proceed to T6.

In the next step ST6, it is checked whether or not the absolute value of the difference between the detected rotational speed Na and the rotational speed Nb used for comparison is larger than a predetermined value ΔNs (ST).
6). In Nb, the previously detected rotation speed is stored.
“a” stores the number of rotations detected this time. Therefore,
In this step, the number of revolutions of the generator 1 is increased by a predetermined amount ΔNs
It is checked whether or not it has fluctuated.

When the rotation speed of the generator 1 fluctuates by a predetermined amount ΔNs or more and the absolute value of the difference between Na and Nb is larger than ΔNs (Y), the duty calculation circuit 12
The value of the initial duty table Tbl_A stored in advance is read (ST7). Initial duty table Tbl_
A is Du which can secure a minimum current required for power supply to the load (auxiliary equipment) 4 and can secure an output current which does not cause a fuse trip or a burnout due to an overcurrent.
The value of ty is described. What is the minimum required current value?
For example, 10A. Initial duty table Tbl_A
Indicates the value of the duty for each rotation speed, and the value of the duty corresponding to the rotation speed Na at this time is read. If the rotation speed of the generator 1 has not fluctuated by the predetermined amount ΔNs or more and the absolute value of the difference between Na and Nb is not larger than ΔNs (N), the step ST7 is not executed and the process proceeds to the step ST8. .

In step ST8, the value of Na is substituted for Nb. That is, the value of the rotational speed detected this time is moved to the area where the previous value is stored. Next, the boost control circuit 1
3 starts boost switching control (ST9). Then, the boost rectifier circuit 2 boosts and rectifies the output voltage of the generator 1, applies a predetermined DC current to the battery 3, and gradually increases the voltage of the battery 3. The voltage of the battery 3 charged by the DC current is detected by the voltage detection circuit 8, and the detection value Vba is sent to the comparison circuit 11. The comparison circuit 11 receives the detection value Vba (ST10).

The comparison circuit 11 compares the detected value Vba of the voltage sent from the voltage detection circuit 8 with the set value Vbs of the voltage sent from the reference voltage circuit 9, and these values are almost the same. If both are within the predetermined range (Y), the process returns to step ST2. If it is not within the predetermined range (N), the comparison circuit 11 checks the magnitude relation between the detection value Vba and the set value Vbs (ST12), and
If a <set value Vbs (Y), the Duty operation circuit 1
2 is the output increasing side Dut stored in the storage device 10 in advance.
The value of the y table Tbl_C is read (ST13). Since the Duty value for each rotation speed is also written in the output increasing duty table Tbl_C, the Duty value corresponding to the rotation speed Na at this point is read. If the detected value Vba is not smaller than the set value Vbs (N), Duty
The arithmetic circuit 12 reads the value of the output reduction duty table Tbl_B stored in the storage device 10 in advance (ST
14). The output reduction duty table Tbl_B also has
Since the value of the duty for each rotation speed is written, the value of the duty corresponding to the rotation speed Na at this time is read.

The change from the initial duty table Tbl_A to the output reduction duty table Tbl_B or the output increase duty table Tbl_C is performed based on the number of operations of the load (auxiliary equipment) 4 based on the detected number of operations. Is also good.

Then, the duty calculation circuit 12 changes the duty value to be sent to the boost control circuit 13 to the read value (ST15). Then, Dut of the control waveform sent from the boosting control circuit 13 to the transistors S1, S2, S3
y is changed. Thereafter, the process returns to step ST2, and the above operation is repeated.

FIG. 10 is a flowchart showing another embodiment of the operation for selecting the duty table. This flow is executed instead of steps S11 to S14 in FIG. That is, step S1 in FIG.
At 0, the comparison circuit 11 calculates the difference ΔV between the detected voltage Vba and the set value Vbs after inputting the detected value Vba of the voltage between both ends of the battery 3 (ST16). And
The value of Duty corresponding to the value of the difference ΔV is stored in the storage device 10.
Is read from the Duty table. At this time, Dut
In the y table, the initial Duty and the output reduction D
Duty of only three systems, i.e., duty and the output increasing side Duty
Instead of the y table, a duty table is stored in which each of the output reduction side and the output increase side is divided into a plurality of systems according to the degree of reduction and increase. Then, depending on how much the detected value of the voltage is from the set value, D
Switching from which sequence of the duty table a duty value is selected. With such a configuration, more efficient and efficient power generation control is possible.

[0054]

According to the present invention, according to the first aspect of the present invention,
The duty ratio corresponding to the rotation speed is read from the storage means, and the switching element in the boost rectifier circuit is chopped by the read duty ratio to control the output current of the boost rectifier circuit. Regardless of the number of revolutions of the generator, the power is adjusted within a certain range and supplied to the power storage device and the load. Therefore, in the generator, a current adjusted to an appropriate amount of current can be supplied to the power storage device and the load without consuming an extra current for generating a magnetic field, thereby improving charging efficiency. Can be.

According to the second aspect of the present invention, the comparing means includes:
The detected voltage output from the voltage detecting means is compared with a preset reference voltage. If the comparison result shows that the detected voltage is larger than the reference voltage, the duty correcting means determines the first duty ratio from the storage means. If the detected and detected voltage is lower than the reference voltage, the duty correction means fetches the second duty ratio from the storage means. If the voltage of the power storage device is higher than the reference voltage, the output current of the boost rectifier circuit Is reduced and is smaller than the reference voltage,
The output current of the boost rectifier circuit is increased. Therefore, the voltage of the power storage device that is charged by the output current of the boost rectifier circuit without generating excessive power is controlled so as to be constantly maintained at a constant level. Efficiency can be improved.

Further, in the invention according to claim 3, the deviation calculating means calculates a deviation between the detected voltage output from the voltage detecting means and a preset reference voltage, and the duty correcting means comprises:
The duty ratio for reducing the deviation is obtained from the storage means. Therefore, since the duty ratio is changed in a direction in which the deviation decreases, the voltage of the power storage device charged by the output current of the boosting rectifier circuit without generating excessive power is controlled so as to be always kept constant. .

According to the fourth aspect of the present invention, the storage means comprises:
Since the duty ratio at which the generated current for each rotation speed is equal to or more than the predetermined value is stored in advance, the minimum current required by the load is secured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an automobile power supply device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a state in which the power supply device according to the embodiment of the present invention is incorporated in an automobile.

FIG. 3 shows three phases (U-phase, V-phase, W-phase) output from the generator 1
Phase) waveform and the operation of the transistors S1, S2, S3 (O
(N, OFF state).

FIG. 4 is a diagram showing operations of transistors S1, S2, and S3 during a period T1 shown in FIG.

FIG. 5 is a diagram showing operations of transistors S1, S2, and S3 during a period T2 shown in FIG.

FIG. 6 is a timing chart shown in FIG.
6 is a timing chart clearly showing ON and OFF of transistors S1, S2, and S3.

FIG. 7 shows the number of rotations of the generator 1 at each duty;
5 is a graph showing a relationship with an output current output from the boost rectifier circuit 2.

FIG. 8 shows the number of rotations of the generator 1 at each duty;
4 is a graph showing a relationship between the efficiency of the boost rectifier circuit 2 and the boost rectifier circuit 2.

FIG. 9 is a flowchart showing the operation of one embodiment of the present invention.

FIG. 10 is a flowchart showing another embodiment of the operation of selecting a duty table.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 generator magnet generator 2 step-up rectifier circuit 3 battery power storage device 4 load 5 controller 6 voltage (phase) detection circuit 7 rotation speed detection circuit (rotation speed detection means) 8 voltage detection circuit 9 reference voltage circuit 10 storage device (storage) Means) 11 Comparison circuit 12 Duty operation circuit 13 Step-up control circuit (step-up control means) 14 Engine 15 Transmission 16 Drive wheel D1, D2, D3 Diode S1, S2, S3 Transistor (switching element) K1, K2, K3 Parasitic diode

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G060 CA13 DA01 DB01 5H590 AA02 AA15 AB02 CA07 CA23 CC02 CC18 CC24 CD01 CE05 CE08 CE10 DD72 EA13 EB02 EB21 FA08 FB01 FB03 FC12 FC14 FC17 GA04 GB05 HA01 HA02 HA10 HA27 JA02 JB02

Claims (4)

[Claims] 1. A magnet generator driven by an internal combustion engine to generate an alternating current, and a step-up and rectification of the alternating current generated by the magnet generator,
A boost rectifier circuit that outputs a DC current; a power storage device that stores the DC current output by the boost rectifier circuit; a load that is driven by the DC current supplied from the power storage device or the boost rectifier circuit; A power supply device for a vehicle, comprising: a control device for controlling a circuit; wherein the boosting rectifier circuit includes a switching element for chopping and boosting an alternating current generated by the magnet generator; Rotation speed detection means for detecting the rotation speed of the machine; and storage for storing in advance a duty ratio between an ON period and an OFF period during chopping of the switching element corresponding to the rotation speed detected by the rotation speed detection device. Means for reading a duty ratio corresponding to the number of rotations detected by the number of rotations detection means from the storage means; Automobile power unit being characterized in that a step-up control means for chopping the switching element. 2. The storage device according to claim 1, wherein said storage means is set according to a first duty ratio at which an output current of said step-up rectifier circuit is reduced from an initial value, said first duty ratio being set according to a rotation speed.
A second output current of the step-up rectifier circuit increases from an initial value;
The control device detects a voltage of the power storage device and outputs a detection voltage; a detection voltage output by the voltage detection device; Comparing means for comparing with a reference voltage; as a result of comparison by the comparing means, when the detected voltage is larger than the reference voltage, the first duty ratio is taken out from the storage means; And a duty correction means for extracting a second duty ratio from the storage means.
The power supply device for an automobile according to claim 1. 3. The storage device stores, in advance, duty ratios of a plurality of systems in which the output current of the boost rectifier circuit decreases or increases from an initial value, the duty ratio being set according to a rotation speed. Voltage detecting means for detecting a voltage of the power storage device and outputting a detected voltage; deviation calculating means for calculating a deviation between the detected voltage output by the voltage detecting means and a preset reference voltage; The vehicle power supply device according to claim 1, further comprising: a duty correction unit that extracts a duty ratio for reducing the deviation calculated by the calculation unit from the storage unit. 4. The vehicle power supply device according to claim 1, wherein said storage means stores in advance a duty ratio at which a generated current for each rotation speed is equal to or more than a predetermined value. .