JP2001178014A - Dc power supply unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply unit for vehicle, capable of attaining igni tion phase control to an AC generator for outputting 42V, using a simple struc ture and obtaining 14V output. SOLUTION: Noting that the AC generator 32 cannot use the ignition phase control by time because its rotational speed fluctuates by a large amount, corresponding to the rotational speed of a motor, while the 42 V voltage, or the phase voltage of respective phases outputted from an armature winding 42 is controlled constantly by adjusting the field current to a field winding 40 with respect to the fluctuation in rotational speed by an excitation circuit 41. A control circuit 36 controls the ignition phase of a thyristor 33c, based on the phase voltage and reference voltage generated by a reference voltage source 43. The reference voltage or the like is adjusted, thus it is possible to obtain constant 14V DC voltage at all times, irrespective of its rotational speed with a simple circuit comparing the phase voltage with the reference voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle DC power supply for supplying a plurality of mutually independent high voltage and low voltage voltages from a single vehicle AC generator.

[0002]

2. Description of the Related Art At present, electrical components for passenger cars are mainly of 12V specification, and the voltage is a specification that a DC voltage obtained by rectifying an output of an AC generator is 14V and a battery voltage is 12V. On the other hand, in order to improve control performance, the control of the vehicle control system has shifted from mechanical control to electric control, and the load of on-vehicle electrical components, which is a load, is increasing. Since an increase in the current due to the increase in the load causes a problem of an increase in the amount of the wire harness, as a next-generation vehicle power supply system, the size and the size of the wire harness are reduced by increasing the DC power supply system to reduce the current. Proposals have been made to reduce weight.

For example, Kassakian, J. "Herausforderung
en der neuen 42V Architektur undFortschritte in de
r internationalen Akzeptanz "(" Challenges of the Ne
w 42Volt Architecture and Progress on Its Intrenat
ional Acceptance ") 1998, VDI Berichte NR.1415, pp.21-
The circuit 35 has a circuit in which the output of the AC generator is increased, the rectified DC voltage is 42 V (battery voltage specification is 36 V), and the DC voltage is 14 V for compatibility with conventional electric components.
There has been proposed a DC power supply system for a vehicle which has a system (battery voltage specification is 12 V).

In supplying the above-mentioned two kinds of high and low voltages, for example, as shown in FIG. 8, the output voltage of the AC generator 2 of the vehicle DC power supply 1 is set to a high voltage of 42 V and the three-phase bridge rectifier 3 It is conceivable that the rectified DC voltage is directly supplied to the high-voltage battery 4 and the load 5, and the DC voltage is reduced by the DC-DC converter 6 that converts the voltage from 42 V to 14 V, and then supplied to the low-voltage battery 7 and the load 8. The AC generator 2 is driven by a prime mover (not shown), and the three-phase AC voltage generated in the three-phase armature winding 9 is full-wave rectified by the three-phase bridge rectifier 3.
The high DC voltage is obtained.

[0005] A field winding 10 of the AC generator 2 is supplied with a field current by a battery 4 (external excitation) at the time of startup and a rectified DC voltage (self-excitation) after startup via an excitation circuit 11. Is given. The AC voltage generated in the armature winding 9 is controlled to the constant voltage of 42 V by adjusting the field current by the excitation circuit 11. The DC-DC
The converter 6 obtains an output voltage of 14 V from the input voltage of 42 V by its own output voltage control function, and the 14 V output is not affected by the fluctuation of the 42 V power supply. Are controlled independently of each other.

[0006]

As a power supply system for a vehicle, the capacity of the load 8 may exceed 100 A. For such a large capacity, the DC-DC converter 6 is used as described above. In the configuration, the conversion efficiency becomes about 85% due to the increase in size of the inductor and the like, there is a problem that the efficiency is lower than that of the DC-DC converter of general home appliances of about several A, and a problem that the cost and the installation space increase. There is also.

Japanese Patent Laid-Open Publication No. Hei 5-91678 discloses a DC power supply for a vehicle which supplies two kinds of high and low voltages without using the DC-DC converter. The prior art is shown in FIG. In FIG.
The same reference numerals are given to portions corresponding to FIG. 8 described above, and description thereof will be omitted.

In this prior art, a vehicle DC power supply 2
1, the three-phase bridge rectifier 3 is divided into two sets indicated by reference numerals 3a and 3b, and the battery 4 is also divided into two sets indicated by reference numbers 4a and 4b.
Using the set of diodes 3a and 3b, full-wave rectification of the AC output of the armature winding 9 is given to the high-voltage load 5 and batteries 4a and 4b, and full-wave rectification by the diode 3a and the thyristor 3c The output is supplied to the low-voltage load 8 and the battery 4a. The thyristor 3c is connected to batteries 4a, 4 provided via voltage dividing resistors r1, r2.
b corresponding to the difference between the divided voltage value of the high-voltage output voltage of the battery 4a and the low-voltage output voltage of the battery 4a alone.
2 is on / off controlled. Between the thyristor 3c and the battery 4a, a filter circuit 23 for smoothing a voltage fluctuation due to the on / off control is interposed.

In the prior art as described above, the battery 4a
The thyristor 3c is only turned on or off in accordance with the difference between the output voltage of the thyristor 3c and the output voltage of the batteries 4a and 4b. For example, when the field current is large, the use of a large-capacity load such as audio is not possible. When the operation is stopped, the control by the control circuit 22 may not catch up with some phases (the thyristor 3c cannot be easily turned off), and the battery 4a may be overcharged. On the other hand, if the DC voltage after rectification becomes too high, water is electrolyzed to the battery and hydrogen is generated. Therefore, the DC voltage after rectification is higher than the output voltage of the battery 4a. It must be controlled to a certain voltage.

Therefore, it is necessary to control the firing phase of the thyristor 3c. Here, in general firing phase control, for example, a sine wave having the same phase as the line voltage is created by a transformer, and rises in response to a synchronization pulse generated at a zero cross of the sine wave, and decreases by discharge. This is realized by slicing the charging voltage of the capacitor at the feedback level and determining the firing phase.

However, the alternator 2 has a problem that the rotation speed thereof is large in correspondence with the rotation speed of the prime mover and fluctuates, for example, by a factor of ten or more, so that the above-described time-based ignition control cannot be used. is there. There is also a problem that the control circuit is complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a DC power supply device for a vehicle which has a simple structure and can always obtain a constant DC voltage regardless of the rotational speed.

[0013]

The vehicle DC power supply of the present invention is applied to a three-phase AC generator for a vehicle in which the generated voltage is controlled to be constant by adjusting the field current. A DC power supply for deriving a voltage output, comprising a bridge rectifier circuit, a first DC output circuit for outputting a first DC voltage by full-wave rectifying an AC output of an armature winding of the three-phase AC generator. And a second dc voltage lower than the first dc voltage by performing full-wave rectification on the ac output of the armature winding of the ac generator and a bridge rectifier circuit having a rectifying element capable of controlling the ignition phase. A second DC output circuit that outputs a reference voltage, a reference voltage source that generates a predetermined reference voltage, and a control circuit that performs a firing phase control based on the phase voltage of each phase and the reference voltage. And

According to the above configuration, when the ignition phase control is performed to output the second DC voltage lower than the first DC voltage, the three-phase AC generator for the vehicle operates at the rotational speed of the prime mover. The first DC voltage, and thus the phase voltage of each phase output from the armature winding, is corresponding to the rotation speed, although the rotation speed fluctuates correspondingly and the firing phase control by time cannot be used. Paying attention to the fact that the current is controlled to be constant by adjusting the field current to the field winding against the fluctuation, the ignition phase control is performed based on the phase voltage and the reference voltage.

Therefore, by adjusting the reference voltage and the like, it is possible to obtain a constant second DC voltage with a simple circuit for comparing the phase voltage with the reference voltage regardless of the rotational speed.

Further, in the vehicle DC power supply of the present invention,
The control circuit, when performing the ignition phase control of a certain phase, performs the ignition control when the phase voltage of the next phase in the phase rotation order with respect to that phase becomes equal to or higher than the reference voltage. Features.

According to the above configuration, the phase to be controlled, such as that used in normal ignition phase control, for example, the voltage of the U phase is higher than the voltage of the phase preceding the phase rotation order, that is, the voltage of the W phase. Instead of using a certain time point as a phase reference point, a time point at which the voltage of the next phase in the phase rotation order, that is, the V phase becomes equal to or higher than the voltage of the W phase preceding the phase rotation order, is used as a phase reference point, The control range from the phase reference point until the phase voltage of the phase becomes 0 is defined as a control range. That is, when the time when the voltage of the U-phase becomes equal to or higher than the voltage of the W-phase is set to 0 ° of the phase reference point,
The range of 60 ° to 180 ° is the control range.

By limiting the control range in this way, when performing the ignition phase control of a certain phase as described above, the phase voltage of the next phase in the phase rotation order with respect to that phase is higher than the reference voltage. The constant second DC voltage can be always obtained only by performing the ignition control at the point in time, and the control circuit can be realized by a simple circuit that compares the phase voltage with the reference voltage.

Further, in the DC power supply device for a vehicle according to the present invention, when the control circuit performs the ignition phase control of a certain phase, the control voltage is also supplied from the next phase of the phase rotation order. It is characterized by the following.

According to the above configuration, not only the detection of the ignition timing but also the supply of the control voltage from the next phase (V) of the phase (U) for performing the ignition phase control, as described above. Since the phase voltage of the next phase (V) is delayed by 60 ° with respect to the phase voltage of the phase (U) for which the ignition phase control is to be performed, the phase (U) for which the ignition phase control is to be performed. In the above control range, the phase voltage of the next phase (V) is high, and the control voltage can be made higher than when the phase voltage of the own phase (U) is used as the control voltage.

In the DC power supply for a vehicle according to the present invention,
The control circuit supplies the control voltage from a battery to which a first DC output circuit is connected.

According to the above configuration, since the relatively high first DC voltage is used as the control voltage, the control voltage can be increased.

Still further, in the vehicle DC power supply according to the present invention, the reference voltage source changes the reference voltage in response to the second DC voltage fed back by a feedback circuit. .

According to the above configuration, the ignition phase is controlled even if the load is light, so that the second DC voltage,
Therefore, the voltage of the battery connected to the second DC output circuit is stabilized at a predetermined value, and overcharging of the battery can be prevented.

Also, in the vehicle DC power supply of the present invention,
The reference voltage source changes the reference voltage in response to an output from an overcurrent protection circuit.

According to the above configuration, when an overload occurs, the ignition phase is delayed, and the power supplied to the load is reduced, so that the overload state can be prevented from continuing.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing a schematic configuration of a vehicle DC power supply 31 according to a first embodiment of the present invention. In this vehicle DC power supply 31, when supplying two kinds of high and low voltages, the output voltage of the AC generator 32 is set to a high voltage of 42V which is the first DC voltage, and the diode 3
DC voltage after full-wave rectification by a three-phase bridge rectifier, which is a first DC output circuit composed of 3a and 33b,
A three-phase mixed bridge rectifier which is directly applied to a high voltage battery 34 and a load 35 and is a second DC output circuit constituted by a diode 33a and a thyristor 33c which are part of the bridge rectifier of the first DC output circuit By the ignition phase control by the control circuit 36, the DC voltage after the full-wave rectification converted from 42V to the second DC voltage of 14V is supplied to the low-voltage battery 37 and the load 38.

The high-voltage battery 34 and the load 35
Is connected between the high-voltage output terminal PH and the ground-level output terminal PC, and is connected to the low-voltage battery 37 and the load 3.
Reference numeral 8 is connected between the low-voltage output terminal PL and the output terminal PC. Further, a filter circuit 39, which includes a smoothing reactor L and a capacitor C0, and intervenes between the output terminals PL and PC for smoothing voltage fluctuations caused by the firing phase control of the thyristor 33c, is interposed.

The field winding 40 of the alternator 32 has
Through the excitation circuit 41, a field current is given by the battery 34 (separate excitation) at the time of startup and by a rectified DC voltage (self-excitation) after startup. The field current is supplied to the exciting circuit 41.
Is adjusted so that the rectified average DC output voltage of the AC voltage generated in the armature winding 42 becomes the constant voltage of 42V. On the other hand, the control circuit 36
A reference voltage created using the output voltage of the high-voltage battery 34 is provided from a reference voltage source 43,
The control circuit 36 performs the ignition phase control of the thyristor 33c using the reference voltage and the phase voltage of each phase as described below, and the average DC output voltage after rectification becomes 14V. Control.

FIG. 2 shows the specific configuration of the reference voltage source 43 and the control circuit 36.
It is a block diagram of. In FIG. 2, the AC generator 32, the excitation circuit 41, the filter circuit 39, and the snubber circuit for absorbing the surge voltage caused by the ignition of the thyristor 33c are omitted. The reference voltage source 43 includes a resistor R1 and a Zener diode ZD1 connected in series between the output terminals PH and PC.
A constant Zener voltage Vzd by the Zener diode ZD1 is output by using a voltage obtained by smoothing a DC voltage after full-wave rectification by a three-phase bridge rectifier constituted by a and 33b by a battery.

The control circuit 36 includes a determination circuit 44 and a drive circuit 45. For example, in controlling the U-phase thyristor 33cu, the AC generator 32
Of the V-phase from the output terminal PV is taken into the determination circuit 44, and is compared with the Zener voltage Vzd by the control transistor Qu1 via the input resistor Ru1.
When v + Vbe> Vzd, the control transistor Qu1
Is turned on, and a firing pulse is applied from the base current limiting resistor Ru2 to the thyristor 33cu via the control transistor Qu2 of the drive circuit 45. Vb
e is a base-emitter voltage of the control transistor Qu1. In connection with the control transistor Qu1, diodes Du1 and Du2 for surge absorption due to the on / off operation of the control transistor Qu1 are provided, and the output of the control transistor Qu2 is supplied to the thyristor 33cu via a diode Du3 and resistors Ru3 and Ru4. Given to.

Similarly, regarding the V-phase thyristor 33cv, the control transistors Qv1 and Qv2 and the resistors Rv1 to Rv4 are determined based on the W-phase voltage Vw from the output terminal PW of the AC generator 32 and the Zener voltage Vzd. And the ignition phases are controlled by the diodes Dv to Dv3. Regarding the W-phase thyristor 33cw, the U-phase voltage Vu from the output terminal PU of the AC generator 32 and the Zener voltage Vc
zd, the control transistors Qw1, Qw2,
The ignition phase is controlled by the resistors Rw1 to Rw4 and the diodes Dw to Dw3.

FIG. 3 is a waveform diagram for explaining the control of the firing phase of the thyristor 33c. Hereinafter, a case where the U-phase control is performed will be described. As described above, the first DC voltage has an average voltage of 42 V (the peak voltage is 42 V ÷ 1.
05 × 1.35 = 46 V), and the rectified ripple voltage is absorbed by the battery 34 and sufficiently smoothed.

FIG. 3 (a) shows a phase voltage generated in the armature winding 42 of the AC generator 32, and FIG. 3 (b) shows a rectification thereof by a three-phase mixed bridge rectifier comprising a diode 33a and a thyristor 33c. This is the later voltage. Normally, the firing phase control of the thyristor is performed as shown in FIG.
It is controlled by the angle α (= time) from the zero cross point of the waveform. For example, in the U-phase, a point in time when the voltage becomes equal to or higher than the voltage of the preceding phase of the phase rotation order, that is, the voltage of the W-phase is set as the phase reference point t0. On the other hand, in the present invention, although the control range is narrowed, the phase reference point is set so that the voltage of the next phase of the phase rotation order, that is, the voltage of the V phase is the voltage of the W phase preceding the phase rotation order. The time point when the above becomes the phase reference point t
0 ', and a range from the phase reference point t0' to the time point t1 when the phase voltage of the phase becomes 0 is defined as a control range β. That is, when the phase reference point t0 is 0 °, 60 ° to 1 °
The range of 80 ° is the control range. Since the second DC voltage has an average voltage of 14 V, a desired voltage output can be obtained even in such a control range.

The firing angle for obtaining the average voltage of 14 V by the firing phase control is indicated by hatching in FIG. 3C, and the angle α is α = cos ⁻¹ (14V / 42V × 2-1) ≒ 110 °.

In the example of the U phase, when α = 110 °, the V phase is W
This is timing t2, which is 50 ° ahead of the phase reference point t0 ', which is larger than the phase. In terms of the voltage value, the peak value on the output side of the three-phase bridge rectifier including the diodes 33a and 33b is 46V. Therefore, in the W phase, 46 V × sin (180 ° + 50 °) = − 35 V, and in the V phase, 46 V × sin (350 °) = − 8 V. At this time, the negative side of the V phase and the W phase Since the diode 33a is conducting and the negative side of the output of the rectifier circuit is at the same potential, the potential seen from the V phase from the negative side of the output of the rectifier circuit is 35-8 = 27V. Is always constant. The firing timing can be determined for the V phase and the W phase in the same manner.

Therefore, it is understood that the average voltage of 14 V can be obtained by setting the Zener voltage Vzd to this 27 V. FIG. 3 (u),
3 (v) and 3 (w) show on / off operations of the thyristors 33cu, 33cv, 33cw, respectively.

A normal three-phase AC generator is 50-60 Hz
, While the three-phase alternator for vehicles fluctuates greatly according to the rotation speed of the prime mover, and cannot use the firing phase control with time. However, as described above, the first DC voltage is 4
Focusing on the fact that the voltage is controlled to a constant voltage of 2 V, the ignition phase control is performed based on the phase voltage and the zener voltage Vzd, which is a reference voltage.
In performing the ignition phase control of V and W, the control range is limited, and the phase voltages Vv, Vw and Vu of the next phases V, W and U of the phase rotation order with respect to the phases U, V and W are determined. The ignition control is only performed when the voltage becomes equal to or higher than the zener voltage Vzd. Therefore, by adjusting the zener voltage Vzd, the second DC voltage that is always constant regardless of the rotation speed is set to the phase voltage and the phase voltage. It can be obtained with a simple circuit that compares the voltage with the zener voltage Vzd.

The thyristor 33c serves both rectifying operation and phase control, and the thyristor 33c has only a small conduction loss, and the control circuit 36 is composed of a small signal electronic circuit. It can be integrated, can be built in the alternator 32, and can be reduced in size and integrated.

FIG. 4 shows a second embodiment of the present invention.
It is as follows if it explains based on.

FIG. 4 is a block diagram of a vehicle DC power supply device 51 according to a second embodiment of the present invention. 4, the AC generator 32, the excitation circuit 41, the filter circuit 39, and the snubber circuit for absorbing the surge voltage caused by the ignition of the thyristor 33c are omitted. In this vehicle DC power supply device 51, similar to the above-described vehicle DC power supply device 31, corresponding portions are denoted by the same reference numerals, and description thereof will be omitted.

The control circuit 5 of the vehicle DC power supply 51
6, between the determination circuit 44 and the drive circuit 45,
An amplifier 52 is provided. The ignition pulse from the NPN-type control transistor Qu1 is transmitted from the base current limiting resistor Ru2 to the PNP-type control transistor Qu1.
3 whose collector current is equal to the resistance Ru
5 and the NPN-type control transistor Qu4, and the PNP from the base current limiting resistor Ru6.
In the form of a control transistor Qu2. In this way, the ignition pulse is amplified by the control transistors Qu3 and Qu4, and supplied to the control transistor Qu2.

Similarly, for the V phase, the ignition pulse is amplified by control transistors Qv3, Qv4 and resistors Rv5, Rv6, and for the W phase, the ignition pulse is amplified by control transistors Qw3, Qw4 and resistors Rw5, Rw6. Is done.

In this vehicle DC power supply device 51, the control circuit 56 supplies the control voltage from the battery 34 to which the first DC output circuit is connected, and amplifies the ignition pulse. One DC voltage is used as the control voltage, and the control voltage can be increased.

FIG. 5 shows a third embodiment of the present invention.
It is as follows if it explains based on.

FIG. 5 is a block diagram of a vehicle DC power supply 61 according to a third embodiment of the present invention. In the vehicle DC power supply 61, the vehicle DC power supply 5
Similar parts to those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

The control circuit 6 of the vehicle DC power supply 51
In No. 6, the amplifier has a one-stage configuration of the NPN-type control transistors Qu4, Qv4, and Qw4. In response, the first-stage control transistor Q
u11, Qv11, and Qw11 are of the PNP type, and the second-stage control transistors Qu12, Qv12, and Qw12 are of the NPN type. Also, the control transistor Qu1
2, Qv12, Qw12 and control transistor Qu4,
Qv4 and Qw4 are connected by coupling capacitors Cu, Cv and Cw, respectively, and the firing pulse has a power saving configuration in which the thyristors 33cu, 33cv and 33cw are given only at the moment of firing. .

FIG. 6 shows a fourth embodiment of the present invention.
It is as follows if it explains based on.

FIG. 6 is a block diagram of a vehicle DC power supply 71 according to a fourth embodiment of the present invention. In the vehicle DC power supply 71, the vehicle DC power supply 3
1 and 51, corresponding portions are denoted by the same reference numerals, and description thereof will be omitted.

In the DC power supply 71 for a vehicle, the control circuit 76 performs not only the detection of the ignition timing but also the control voltage in performing the ignition phase control of a certain phase. Supplied from the phase. That is, for example, when performing the U-phase firing phase control, the control transistor Q
u2 amplifies the ignition pulse by the control voltage from the next V phase and outputs the amplified pulse to the thyristor 33cu. Similarly, the control transistor Qv2 amplifies the firing pulse by the control voltage from the W phase and outputs it to the thyristor 33cv, and the control transistor Qw2 amplifies the firing pulse by the control voltage from the U phase to the thyristor 33cw. Output.

With this configuration, the phase supplying the control voltage is delayed by 60 ° with respect to the phase voltage of the phase for which the ignition phase control is to be performed. The phase voltage of the phase that supplies the control voltage in the control range β is high, as compared with the case where the phase voltage of the phase itself for which the ignition phase control is to be performed as in the vehicle DC power supply 31 is used as the control voltage. The control voltage can be increased.

FIG. 7 shows a fifth embodiment of the present invention.
It is as follows if it explains based on.

FIG. 7 is a block diagram of a vehicle DC power supply 81 according to a fifth embodiment of the present invention. In the vehicle DC power supply 81, the vehicle DC power supply 6
Similar parts to those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

In the DC power supply device 81 for a vehicle, the control circuit 86 includes the feedback circuit 82 and the overcurrent limiting circuit 83 in addition to the control circuit 66. The feedback circuit 82 includes a Zener diode Z
D2, voltage dividing resistors R2, R3 and control transistor Q1
It is provided with. The series circuit of the Zener diode ZD2 and the voltage dividing resistors R2 and R3 is connected to the output terminal PL,
A voltage obtained by subtracting the Zener voltage of the Zener diode ZD2 from the voltage between the output terminals PL and PC and divided by the voltage dividing resistors R2 and R3 is provided to the base of the control transistor Q1. . The collector of the control transistor Q1 is connected to the control transistors Qu11, Qv1 via resistors Ru7, Rv7, Rw7, respectively.
1, Qw11.

Therefore, when the second DC voltage increases, the collector current I1 of the control transistor Q1 increases, and the current I1 divides the output voltage of the armature winding 42, so that the control transistor Qu11, Qv
11, Qw11 is turned on is the Zener voltage Vzd.
Higher, and thus the firing angle is slowed, so that the second DC voltage is controlled to be lower. On the contrary,
When the second DC voltage decreases, the firing angle is controlled to increase and the second DC voltage increases.

In this way, the feedback control corresponding to the second DC voltage is performed, and the ignition phase is controlled even when the load is light, so that the on-voltage drop and the smoothing in the three-phase mixed bridge rectifier are performed. The battery 37 also protects against voltage drop due to the reactor L and the wire harness.
Is stabilized at a predetermined value, and overcharging of the battery 37 can be prevented.

The control transistors Qu11, Qv1
1, a resistor Ru that determines the voltage dividing ratio of the base voltage of Qw11
1, Rv1, Rw1: the resistance values of Ru7, Rv7, Rw7 and the voltage dividing resistors R2, R3 for determining the voltage dividing ratio of the base voltage of the control transistor Q1, and the control transistor Q
By adjusting the current amplification factor of 1, the output characteristics of the second DC voltage can be adjusted, and the Zener voltage Vzd can be arbitrarily set. Further, by adjusting the output characteristics, the filter circuit 39 is controlled.
Of the smoothing reactor L and the capacitor C0 can also be set arbitrarily.

Similarly, the overcurrent limiting circuit 83 includes a current detecting resistor R4 and a control transistor Q2. The current detection resistor R4 is interposed in series with a load line between the anode of the diode 33a and the output terminal PC. The current detection resistor R4 is interposed between the base and the emitter of the control transistor Q2, and the collector is connected to the bases of the control transistors Qu11, Qv11, and Qw11 via resistors Ru8, Rv8, and Rw8, respectively.

Therefore, as the load current increases, the collector current I2 of the control transistor Q2 increases, and the current I2 divides the output voltage of the armature winding 42 together with the current I1.
The voltage at which 1, Qv11 and Qw11 are turned on is higher than the Zener voltage Vzd, so that the firing angle is slowed and the second DC voltage is controlled to be low. On the other hand, when the second DC voltage decreases, the firing angle is increased to control the second DC voltage to increase.

As described above, when an overload occurs, the ignition phase is delayed, and the power supplied to the load is reduced.
It is possible to prevent the overload state from continuing.

When the capacity of the load 38 of the DC 14 V system decreases, the output voltage of the battery 37 increases, the firing angle recedes, and the current to the smoothing reactor L is intermittent.
When the current is in a continuous state, the second DC voltage is considered to be the average voltage of the hatched portion in FIG. 3C as described above. 37 equals the output voltage,
If the ignition is performed at 15 V or more, the charging will be continued. In this state, hydrogen is generated from the battery 37,
Not preferred. Therefore, in the feedback control, the second DC voltage is 15V + α, and the first DC voltage is 45V + α.
(The first DC voltage is set to be larger than 45 V at the maximum), and the ignition pulse is not generated in this state. Similarly, it is possible to provide protection against retreat of the ignition phase or pulse cut against overcurrent.

[0063]

The vehicle DC power supply device of the present invention is applied to a vehicle three-phase AC generator in which the generated voltage is controlled to be constant by adjusting the field current, and performs the ignition phase control. When outputting a second DC voltage lower than the first DC voltage, the field current is adjusted according to the rotation speed fluctuation of the prime mover, and the first DC voltage is controlled to be constant. Then, the ignition phase control is performed based on the phase voltage of the first DC voltage and the reference voltage.

Therefore, by adjusting the reference voltage and the like, it is possible to obtain a constant second DC voltage with a simple circuit that compares the phase voltage with the reference voltage regardless of the rotational speed.

Further, in the vehicle DC power supply device of the present invention, when performing the ignition phase control of a certain phase by limiting the control range, the phase voltage of the next phase in the phase rotation order with respect to the phase is controlled. The ignition control is performed at the time when the voltage becomes equal to or higher than the reference voltage.

Therefore, although the control range is narrowed,
The control circuit can be realized by a simple circuit for comparing the phase voltage and the reference voltage.

Further, in the vehicle DC power supply device of the present invention, when performing the ignition phase control of a certain phase, not only the detection of the ignition timing but also the control voltage is controlled by the control voltage next to the phase rotation order. Supply from phase.

Therefore, the phase voltage of the next phase is delayed by 60 ° with respect to the phase voltage of the phase for which the ignition phase control is to be performed, so that the phase voltage of the own phase is used as the control voltage. Thus, the control voltage can be increased.

Further, in the vehicle DC power supply of the present invention, the control voltage is supplied from a battery to which the first DC output circuit is connected.

Therefore, since the relatively high first DC voltage is used as the control voltage, the control voltage can be increased.

Furthermore, the vehicle DC power supply of the present invention changes the reference voltage in response to the second DC voltage fed back by the feedback circuit.

Therefore, the ignition phase is controlled even when the load is light, so that the second DC voltage, that is, the voltage of the battery connected to the second DC output circuit is set to a predetermined value. , And overcharge of the battery can be prevented.

The vehicle DC power supply of the present invention changes the reference voltage in response to the output from the overcurrent protection circuit.

Therefore, when an overload occurs, the ignition phase is delayed, and the power supplied to the load is reduced, so that the overload state can be prevented from continuing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a vehicle DC power supply device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a specific configuration of a reference voltage source and a control circuit in FIG.

FIG. 3 is a waveform diagram for explaining control of a firing phase of a thyristor.

FIG. 4 is a block diagram of a vehicle DC power supply according to a second embodiment of the present invention.

FIG. 5 is a block diagram of a DC power supply device for a vehicle according to a third embodiment of the present invention.

FIG. 6 is a block diagram of a vehicle DC power supply device according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram of a vehicle DC power supply device according to a fifth embodiment of the present invention.

FIG. 8 is a diagram showing an example of a DC power supply device for a vehicle that can supply two kinds of voltages, high and low.

FIG. 9 is a view showing a conventional DC power supply device for a vehicle.

[Explanation of symbols]

31, 51, 61, 71, 81 DC power supply for vehicle 32 AC generator 33a Diode (first DC output circuit, second DC output circuit) 33b Diode (first DC output circuit) 33c Thyristor (second 34, 37 Battery 35, 38 Load 36, 56, 66, 76, 86 Control circuit 39 Filter circuit 40 Field winding 41 Excitation circuit 42 Armature winding 43 Reference voltage source 44 Judgment circuit 45 Drive circuit 52 amplifier 82 feedback circuit 83 overcurrent limiting circuit C0 capacitor Cu, Cv, Cw capacitor Du1 to Du3; Dv1 to Dv3; Dw1 to Dw3
Diode L Smoothing reactor PC, PH, PL output terminal PU, PV, PW output terminal Q1, Q2 Control transistor Qu1-Qu4; Qv1-Qv4; Qw1-Qw4
Control transistors Qu11, Qu12; Qv11, Qv12; Qw11,
Qw12 control transistor R1 resistance R2, R3 voltage dividing resistance R4 current detection resistance Ru1, Rv1, Rv1 input resistance Ru2 to Ru8; Rv2 to Rv8; Rw2 to Rw8
Resistance ZD1, ZD2 Zener diode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H02P 9/14 H02P 9/14 GF term (Reference) 5G060 AA04 AA08 BA06 BA08 CA02 CA03 CA13 DA02 5H006 AA05 BB00 CA03 CA07 CB01 CB02 DA04 DB02 DC05 5H420 BB12 CC05 CC09 DD02 DD05 EA03 EA45 EB05 EB40 FF03 FF22 5H590 AA10 AA15 BB15 CA23 CC01 CC18 CD01 CE10 DD16 DD17 DD64 EA13 EB02 FA06 FB01 FB05 FC12 FC06 GA02 HA02

Claims (6)

[Claims] 1. A DC power supply device applied to a three-phase AC generator for a vehicle in which a generated voltage is controlled to be constant by adjusting a field current, and which derives a plurality of levels of voltage output. A first DC output circuit for full-wave rectifying an AC output of an armature winding of the three-phase AC generator to output a first DC voltage; and a bridge rectifier having a rectifying element capable of controlling a firing phase. A second direct-current output circuit comprising a circuit, the second direct-current output circuit outputting a second direct-current voltage lower than the first direct-current voltage by full-wave rectifying an alternating-current output of an armature winding of the alternating-current generator; A DC power supply device for a vehicle, comprising: a reference voltage source for generating a voltage; and a control circuit for performing a firing phase control based on a phase voltage of each phase and the reference voltage. 2. The control circuit according to claim 1, wherein the control circuit performs the ignition phase control of a certain phase when the phase voltage of the next phase of the phase rotation order with respect to the phase becomes higher than the reference voltage. 2. The DC power supply for a vehicle according to claim 1, wherein the DC power supply is controlled. 3. The control circuit according to claim 1, wherein the control circuit supplies the control voltage from the next phase of the phase rotation order when performing the ignition phase control of a certain phase.
The DC power supply for a vehicle according to the above. 4. The DC power supply according to claim 1, wherein the control circuit supplies the control voltage from a battery to which a first DC output circuit is connected. 5. The apparatus according to claim 1, wherein said reference voltage source changes said reference voltage in response to said second DC voltage fed back by a feedback circuit. DC power supply for vehicles. 6. The DC power supply for a vehicle according to claim 1, wherein the reference voltage source changes the reference voltage in response to an output from an overcurrent protection circuit. .