JP2636635B2 - AC generator for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle alternator capable of supplying electric power to an electric load including a battery of a vehicle.

[0002]

2. Description of the Related Art As shown in FIG. 11, a conventional AC generator for a vehicle is driven by an engine (not shown) and generates an electric power by a rotational motion thereof. A diode bridge 103 which takes in from an input terminal, converts it to direct current, and outputs from a direct current output terminal of the illustrated polarity;
And a voltage regulator 105 that adjusts and controls a field current flowing through a field coil 102 of the synchronous generator 101 so that the DC voltage is taken in from the DC generator. The output terminals 119a and 119b of the vehicle alternator include:
The battery 121 and the vehicle load 123 are connected in parallel. Reference numerals 101u, 101v, and 101w denote armature coils of the synchronous generator 101.

In such a vehicle alternator, when the engine rotates at a certain speed or higher, the synchronous generator 10
1 generates AC power. This AC power is supplied to the AC terminal of the diode bridge 103. The diode bridge 103 converts the input AC into DC and outputs the DC from a DC terminal. This direct current is supplied to the voltage regulator 105
To the battery 121 and the vehicle load 123 via the output terminals 119a and 119b. In the voltage regulator 105, the output terminal 119
The current flowing through the field coil 102 is adjusted so that the DC voltage between the terminals a and 119b is constant.

By the way, in the case of the vehicle alternator,
The relationship between the rotation speed N of the synchronous generator 101 and the current I that can be extracted from the synchronous generator 101 has characteristics as shown in FIG. The reason for such characteristics will be described below.

Assuming that the field magnetic flux of the synchronous generator 101 is Φ, the number of turns of the armature coils 101u, 101v or 101w is Z, the number of revolutions of the generator is N, and the coefficient is K, the output voltage V of the generator is

[0006]

[Formula 1] V = KΦZN, and the number of rotations at which power generation starts (point A in FIG. 13) is obtained by modifying the formula 1,

[0007]

N = V / (KΦZ) Here, since the field magnetic flux Φ is constant, it can be seen from Equation 2 that the rotation speed at the start of power generation is inversely proportional to the armature coil winding number Z.

Further, at point B in FIG. 12, which is the maximum number of rotations used, a magnetomotive force is generated in the armature by the output current.
The output current when the magnetomotive force balances the magnetomotive force of the field becomes the maximum output current of the generator. Assuming that the magnetomotive force of the field is constant, the armature magnetomotive force of the generator is proportional to the number of turns Z of the armature coil, so that the output current at the maximum rotation speed is inversely proportional to the number of turns Z of the armature coil.

Therefore, if the number of turns Z of the armature coil is increased, the number of revolutions at which power generation starts (point A in FIG. 12) can be reduced, but the output current at the maximum number of revolutions (point B in FIG. 12). Decrease. Conversely, when the number of turns Z of the armature coil is reduced, the output current at the maximum rotation speed (B in FIG.
Points), but the number of rotations at which power generation starts (Fig. 1)
2 (point A) becomes faster.

[0010] From this, the synchronous generator, the field flux Φ
And the number of armature coils Z, the output characteristics are uniquely determined, and it is not possible to obtain any characteristics.

[0011]

As described above, according to the conventional automotive alternator, both the number of revolutions at the start of power generation and the output current at the maximum number of revolutions are in inverse proportion to the number of turns of the armature coil. Increasing the number of armature coil turns makes it possible to reduce the number of revolutions at which power is generated.However, there is a disadvantage that the output current at the maximum number of revolutions is reduced. For example, the output current at the maximum rotation speed can be increased, but there is a disadvantage that the power generation start rotation speed is increased.

Therefore, according to the above-described vehicle alternator, when the field magnetic flux and the number of armature coils are determined, the output characteristics thereof are uniquely determined, and it is not possible to obtain an arbitrary characteristic. was there.

The present invention has been made in view of the above circumstances and has solved the above-mentioned drawbacks. The present invention provides a vehicle AC generator capable of extracting an output current with a simple circuit configuration regardless of the number of windings of an armature coil even at a predetermined number of revolutions or less at which power generation is started. The purpose is to provide a machine.

[0014]

In order to achieve the above object, the invention according to claim 1 is connected between an armature coil of a generator and a battery, and rectifies an AC output from the generator. A diode bridge means comprising a plurality of diode elements for supplying a DC component to the battery, and an armature coil of the generator and the diode bridge means so as to short-circuit armature current from the armature coil. Switching means connected therebetween, and control means for continuously turning on and off the switching means under a predetermined condition at a predetermined cycle, and an on period of the switching means is connected to an armature coil of the generator. The short-circuit current is applied and stored as power in the inductance component of the armature coil, and the stored stored power is stored in the diode during the off period of the switching means. Characterized by being configured so as to supply to the battery via the Doburijji means.

According to the second aspect of the present invention, the control means fetches a rotation speed signal from the generator and outputs a signal when the rotation speed of the generator is smaller than a predetermined rotation speed. And a drive circuit for turning on and off the switching means in response to a signal from the rotation detector.

According to the third aspect of the present invention, the rotation detector captures a rotation speed signal from the generator, and the rotation speed from the generator turns on / off the switching means. A circuit configuration for outputting a signal for operating the drive circuit when the number of rotations is equal to or less than the intersection of the output characteristic when the switching unit is turned off and the output characteristic when the switching unit is always turned off. .

Further, according to the invention described in claim 4, the control means takes in a rotation speed signal from the generator, and when the rotation speed of the generator is lower than a predetermined rotation speed,
The switching means is configured to perform an on / off operation at an on / off ratio in which an off time occupying an on / off period gradually changes in response to a continuous change in a rotation speed.

According to the fifth aspect of the present invention, the control circuit outputs a signal such that an output characteristic of the generator has a maximum off-time ratio at a rotation speed that is in contact with a straight line passing through the origin. It is characterized by having been constituted so that.

According to the invention described in claim 6, the diode bridge means and the switching means respectively include a diode element and a switching means of an inverter device used when driving the generator as a motor. It is characterized by comprising.

[0020]

According to the first aspect of the present invention, by turning on the switching means, the short-circuit current flowing through the armature coil of the generator is regulated in one direction, and power is stored in the armature coil. The switching means is turned off. When the switching means is turned off, the stored power is added to the power generated by the armature coil and supplied to the load via the diode bridge means. Therefore, power can be generated even when the power generation start rotation speed is low.

According to the second aspect of the present invention,
When the rotation speed of the generator is smaller than a predetermined rotation speed, the control means turns on and off the switching means. When the rotation speed is smaller than the predetermined rotation speed, a large current can be taken out. When it is larger, the power can be generated at the maximum capacity of the generator.

According to the third aspect of the present invention,
The control means, when the number of revolutions from the generator is less than or equal to the intersection of the output characteristic when the switching means is turned on and off and the output characteristic when the switching means is turned off In order to operate the drive circuit, a large current can be taken out when the rotation speed is lower than the predetermined rotation speed, and power can be generated at the maximum capacity of the generator when the rotation speed is higher than the predetermined rotation speed.

In addition, according to the invention of claim 4, when the rotation speed of the generator is less than or equal to a predetermined rotation speed, the control means occupies an on / off period according to a decrease in the rotation speed. In order to turn on / off the switching means at an on / off ratio such that the off time is reduced, the current increases linearly from the origin to a certain number of revolutions, and above the number of revolutions, the current is extracted with the maximum capacity of the generator. Can be.

In the invention described in claim 5, the rotation speed / voltage conversion circuit outputs a signal such that the output characteristic of the generator has a maximum off-time ratio at a rotation speed in contact with a straight line passing through the origin. Since the output can be performed, it is possible to obtain a characteristic that the current increases linearly according to the rotation speed.

Finally, in the invention according to claim 6, since the diode bridge and the switching means are realized by using the inverter device, the number of parts can be reduced and the battery can be charged even at low rotation.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIGS. 1 to 3 are diagrams for explaining a first embodiment of the present invention, and FIG. 1 is a circuit diagram showing an automotive alternator according to the first embodiment of the present invention.

Referring to FIG. 1, the automotive alternator of the present invention has a synchronous generator 1, a diode bridge 3, a voltage regulator 5, a switching means 9, and a control circuit 11, as follows. Is configured.

The synchronous generator 1 has armature coils 1ua,
1va, 1wa, 1ub, 1vb, 1wb and a field coil 2, and has a structure in which an electromotive force is generated in the armature coils 1ua, 1va, 1wa by rotating the field coil 2 by an engine. . In the synchronous generator 1, the armature coils 1ub, 1vb, 1wb do not contribute to power generation, and are generally called leakage inductance. The armature coils 1ub, 1vb, 1wb of the synchronous generator 1 are connected to AC terminals of the three-phase diode bridge 3, respectively.

The three-phase diode bridge 3 includes diodes Dun, Dvn, Dwn and diodes Dum, Dvm, Dwm, and is configured as follows. The anode of the diode Dun and the cathode of the diode Dum are connected, and this connection point becomes the U-phase AC terminal. Diode D
The anode of vn and the cathode of diode Dvm are connected, and this connection point becomes the V-phase AC terminal. The anode of the diode Dwn and the cathode of the diode Dwm are connected, and this connection point becomes a W-phase AC terminal. The cathodes of the diodes Dun, Dvn, Dwn are commonly connected, and this connection point becomes the + DC terminal. Diode Dum,
The anodes of Dvm and Dwm are commonly connected, and this connection point becomes the -DC terminal. The + DC terminal of the diode bridge 3 is connected to the output terminal 19a, and the -DC terminal of the diode bridge 3 is connected to the output terminal 19b.

The input terminal of the voltage regulator 5 is connected between the output terminals 19a and 19b, and the output terminal of the voltage regulator 5 is connected to the field coil 2.
This voltage regulator 5 has a circuit configuration capable of adjusting and controlling the field current flowing through the field coil 2 of the synchronous generator 1 so that the voltage between the output terminals 19a and 19b is constant. .

In this embodiment, the switching means 9 comprises three-phase transistors Qu, Qv and Qw.
The collector of the transistor Qu is at the connection point of the armature coil 1ub and the diode Dun, the collector of the transistor Qv is at the connection point of the armature coil 1vb and the diode Dvn, and the collector of the transistor Qw is at the connection point of the armature coil 1wb and the diode Dwn. , Are connected respectively. The emitters of the transistors Qu, Qv, Qw are connected to an output terminal 19b via a connection point P that is connected in common. The bases of the transistors Qu, Qv, and Qw are connected to the output terminal of the control circuit 11, and the control circuit 1
The transistors Qu, Qv, Q
w is on / off controlled.

The control circuit 11 includes a transistor Q
On, off signals can be supplied to u, Qv, and Qw. The control circuit 11 includes a drive circuit 13 composed of a transmitter for outputting an on / off control signal, and each control signal from the drive circuit 13 is connected to transistors Qu, Qv, Q
The resistors Ru, Rv, and Rw supplied to each base of w.

The output terminal 1 of such a vehicle alternator
A battery 21 and an electric load 23 are connected in parallel to 9a and 19b.

The operation of the first embodiment configured as described above will be described with reference to FIGS.

First, the operation of the vehicle alternator will be described with reference to FIGS.

FIG. 2 is a time chart for explaining the operation of the first embodiment, and the time t (second) is plotted on the horizontal axis. 2A shows a voltage V, FIG. 2B shows an on / off signal for driving the switching means 9, FIG. 2C shows a current I flowing through the switching means 9, and FIG. 3 (e) shows the current I flowing through the armature coils 1ua, 1va, 1wa.
Are respectively shown.

First, the operation when the on / off control of the switching means 9 is not performed will be described. In this case, when the synchronous generator 1 is generating power at a voltage lower than the voltage Vb of the battery 21, the armature coils 1ua, 1ua of the synchronous generator 1
The voltage generated at va and 1wa is a voltage Vg having a waveform as shown in FIG.

Here, the transistors Qu, Qv, Qw of the switching means 9 are controlled by a control signal from the control circuit 11.
Is turned on for a period t (seconds) for each period T (seconds), as shown in FIG. Then, at the time of ON, the current of the synchronous generator 1 is changed to the armature coil (leakage inductance) 1
ub, 1vb, 1wb, transistor Q of switching means 9
u, Qv, and Qw, the connection point P, and the diode Dum, Dvm, and Dwm of the diode bridge 3 flow through a closed circuit. The amount of change Ion in this current is as follows, where the inductance of each armature coil (leakage inductance) 1ub, 1vb, 1wb is L, respectively.

[0040]

[Formula 3] Ion = (Vg / L) · t, and each armature coil (leakage inductance) 1ub,
The electric power is stored in 1vb and 1wb. At this time, each armature coil (leakage inductance) 1ub, 1vb, 1wb is connected to the emitter-side connection point P of the transistors Qu, Qv, Qw.
Has a waveform as shown in FIG. 2 (c).

On the other hand, when the transistors Qu, Qv, Qw of the switching means 9 are turned off by the control signal from the control circuit 11, the transistor Q of the switching means 9 is turned off.
The voltage due to the current flowing when u, Qv, and Qw are on is superimposed on the generated voltage Vg of the armature coils 1ua, 1va, and 1wa of the synchronous generator 1, and flows into the battery 21 through the diode bridge 3. This current change Ioff is:

[0042]

[Formula 4] Ioff = [(Vb−Vg) / L] · (Tt) The output current from this diode bridge 3 is
The waveform is as shown in FIG. The output current I of each armature coil 1ua, 1va, 1wa of the synchronous generator 1 is
The waveform is as shown in FIG.

And since Ion and Ioff are equal,

[0044]

[Formula 5] (Vg / L) · t = [(Vb−Vg) / L] · (Tt).

[0045]

[Formula 6] Vg = [(T−t) / T] · Vb, and the output voltage Vg of the synchronous generator 1 is (T−t) / T times the battery voltage Vb. Therefore, even if the generated voltage Vg of the armature coils 1ua, 1va, 1wa of the synchronous generator 1 is lower than the voltage Vb of the battery 21, the battery 21 can be charged.

Next, referring to FIG. 1 and FIG.
The relationship between the output current and the number of revolutions of the vehicle alternator of the embodiment will be described.

FIG. 3 is a characteristic diagram showing the relationship between the output current I and the rotation speed N of the generator 1, wherein the horizontal axis indicates the rotation speed N.
And the vertical axis represents the output current I.

In FIG. 3, X indicates the output of the conventional generator, and represents the output characteristic when (Tt) / T = 1, that is, when the switching means 9 is always off. Y represents output characteristics when (T−t) /T=0.5. That is, the synchronous generator 1 that does not switch by the switching means 9 does not generate power below the point A of the X characteristic. On the other hand, (T−t) / T =
In the synchronous generator 1 having switched the switching means 9 at 0.5, the lowest power generation rotation speed moves to the point C of the Y characteristic. The number of rotations at the point C is half the number of rotations of the point A. When the switching means is always turned off, a current can be taken up to point B. However, in the first embodiment, since the switching means is controlled to be on and off, only the off-state current of the current shown in FIG. Since it cannot be taken out, it moves to point D, which is half the current value of point B.

Therefore, when (T−t) /T=0.5, the characteristics are as if the number of turns of the armature coil 1 were doubled.

Further, when the on / off ratio (Tt) / T is gradually decreased from 1, the characteristic is as if the number of turns of the armature coil 1 is T / (Tt) times. It is possible to charge even at a rotational speed that could not be charged by the vehicle alternator.

As described above, in the first embodiment, by using a small number of components (the switching means 9 and the control circuit 11), there is an effect that the characteristics of the generator, which could not be conventionally achieved, can be changed. Will be.

FIG. 4 is a circuit diagram showing a second embodiment of the present invention.

In the second embodiment shown in FIG. 4, the control circuit 11 includes a driving circuit 13 for forming a pulse control signal,
Each control signal from the drive circuit 13 is applied to a transistor Q
resistors Ru, Rv, supplied to the bases u, Qv, Qw, respectively.
Rw and a rotation detector 1 for detecting the number of rotations of the synchronous generator 1
4 are the same as those in the first embodiment, and the same reference numerals in FIG. 4 as those in FIG.
And the same ones are shown. The rotation detector 14 includes:
For example, it is constituted by a rotation sensor attached to the rotating shaft of the generator, configured to detect the rotation speed of the generator 1 and output a signal when the rotation speed is smaller than a predetermined value. When there is an on / off operation signal from the rotation detector 14, the drive circuit 13
The resistance R is connected to each base of the transistors Qu, Qv, and Qw.
The circuit configuration is such that a drive pulse is transmitted via u, Rv, and Rw.

The operation of the second embodiment will be described with reference to FIGS.

In the first embodiment, the on / off ratio (T−
When t) / T is driven at a constant value, a Y characteristic as shown in FIG. 3 is obtained. At a rotation speed lower than the point E, more output current can be taken out than with the conventional generator, but at a rotation speed higher than the point E, Conversely, the output current has become smaller.

Therefore, in the second embodiment, the rotation detector 1
At 4, the rotational speed of the synchronous generator 1 is monitored, and when the rotational speed is lower than the point E, an on / off operation signal is output from the rotation detector 14 to operate the drive circuit 13. Accordingly, when the synchronous generator 1 is rotating at a lower rotation speed than the point E, the drive circuit 13 is operated to control the transistors Qu, Qv, and Qw of the switching means 9 to be on / off. When the rotation speed of the synchronous generator 1 becomes higher than the point E, the rotation detector 14 stops outputting the on / off operation signal and stops the operation of the drive circuit 13. As a result, the transistors Qu, Qv, and Qw of the switching means 9 do not operate, so that the synchronous generator 1 generates power with the conventional characteristic X. As a result, as shown by the solid line in FIG. 5, the vehicular AC generator of the second embodiment can be charged even at a low rotation below the point E, and originally above the point E, The characteristic is such that the current can be taken out with the maximum output that it has.

FIGS. 6 to 9 are diagrams for explaining a third embodiment of the present invention, and FIG. 6 is a circuit diagram showing a third embodiment of the present invention.

In the third embodiment shown in FIG. 6, the control circuit 11 comprises a rotation speed / voltage conversion circuit 15, a conversion drive circuit 16, and resistors Ru, Rv, Rw.
Other configurations are similar to those of the first embodiment. The rotation speed / voltage conversion circuit 15 is configured to take in the rotation speed of the synchronous generator 1 and convert it into a voltage proportional to the rotation speed of the synchronous generator 1. The conversion drive circuit 16 controls the on / off ratio [(T
−t) / T] is converted to a resistance Ru,
Rv and Rw are supplied to the bases of the transistors Qu, Qv and Qw of the switching means 9, and the transistors Q
u, Qv, and Qw can be driven on and off.

The operation of the third embodiment will be described with reference to FIGS.

First, as described above, the output characteristic X of the conventional vehicle alternator has the characteristic shown in FIG. Further, in the third embodiment, assuming that the on / off ratio [(Tt) / T] is fixed to 2/3, 1/2, and 1/3 to drive the switching means 9, as shown in FIG. In addition, characteristics C, D, and E are obtained at each on / off ratio. That is, as can be seen from the characteristics of FIG. 8, the on / off ratio is set to 1 at a rotation speed equal to or higher than a point F (rotation speed Nb) where the conventional characteristic X contacts with a straight line passing through the origin 0, and at a rotation speed lower than that, the rotation speed is reduced. If the on / off ratio is gradually reduced as the power decreases, the maximum output of the generator at each rotation speed can be obtained.

Therefore, in the rotation speed / voltage conversion circuit 15,
A voltage signal is output in proportion to the rotation speed. Conversion drive circuit 1
6, based on the output of the rotation / voltage conversion circuit 15,
As shown in FIG. 7, a control signal for changing the on / off ratio [(T−t) / T] in proportion to the rotation speed is output below the rotation speed Nb, and above the rotation speed Nb, regardless of the rotation speed. (T−t) / T = 1]. The output control signal is applied to the bases of the transistors Qu, Qv, Qw via the resistors Ru, Rv, Rw. Each of the transistors Qu, Qv, Qw is turned on / off by the control signal.

By operating as described above, in the automotive alternator, the relationship between the output current I that can be extracted from the output terminals 19a and 19b and the rotational speed N of the synchronous generator 1 is shown in FIG.
As shown in (1), the current I increases linearly from the rotation speed 0 to the rotation speed Nb, and after the rotation speed Nb, the power generation characteristics are similar to those of the conventional vehicle AC generator.

In the third embodiment, the rotation speed Nb
Has been described in the case where the rotation speed is lower than the use rotation speed. However, if the synchronous generator 1 is selected such that the rotation speed Nb becomes the maximum use rotation speed, the output current linearly increases from the origin 0 to the maximum use rotation speed An increasing vehicle alternator can also be used.

FIG. 10 is a circuit diagram showing a fourth embodiment of the present invention.

In the fourth embodiment, a control circuit for turning on and off the transistor is added to the transistor in the inverter circuit used for the motor generator operation of the synchronous machine, and the diode bridge 3 of the first embodiment is connected to the transistor. The feature is that the switching means 9 is realized. In FIG. 10, reference numeral 17 denotes an inverter circuit, which is composed of transistors Qun and Qv.
n, Qwn, Qum, Qvm, Qwm and diodes Dun, Dv
n, Dwn, Dum, Dvm, and Dwm, and are configured as follows. Diodes Dun, Dvn, Dwn are connected in parallel to the transistors Qun, Qvn, Qwn, respectively. Diodes Dum, Dvm, Dwm are connected in parallel to the transistors Qum, Qvm, Qwm, respectively. The collectors of the transistors Qun, Qvn, Qwn are commonly connected and connected to the output terminal 19a. The emitter of each transistor Qun, Qvn, Qwn is
The collectors of um, Qvm and Qwm are connected in series. The emitters of the transistors Qum, Qvm, Qwm are commonly connected and connected to the output terminal 19b. The emitter of each transistor Qun, Qvn, Qwn and each transistor Qn
The connection points of the collectors of um, Qvm, and Qwm are connected to armature coils 1ub, 1vb, and 1wb, respectively.

The control circuit 11, which is a feature of the fourth embodiment, comprises a driving circuit 13 composed of an oscillation circuit and a resistor R.
u, Rv, consists of a Rw, diodes Dup, Dvp, and Dwp, a control signal from the drive circuit 13, to the base of the transistor Qum through the resistor Ru · diodes Dup, via a resistor R _V · diode Dvp transistor The base of Qvm can be supplied to the base of the transistor Qwm via the resistor Rw and the diode Dwp. The diodes Dup, Dvp, and Dwp are inserted so as not to interfere with signals from the inverter drive circuit.

Other configurations are the same as those of the first embodiment. In FIG. 10, the same reference numerals as those in FIG. 1 denote the same components as those in FIG.

The operation of the fourth embodiment will be described.

When the synchronous generator 1 is used as a synchronous motor, the transistors Qun, Qvn, Qn of the inverter circuit 17 are driven by a drive signal of an inverter drive circuit (not shown).
wn, Qum, Qvm, and Qwm are turned on to convert the DC power of the battery 21 into AC power, and supply the AC power to the armature coils 1ua, 1va, 1wa, 1ub, 1vb, 1wb of the synchronous generator 1. Thereby, the synchronous generator 1 can operate as an electric motor and obtain a motion output from the rotating shaft.

On the other hand, when used as the synchronous generator 1, when an inverter drive circuit (not shown) is stopped, each transistor is turned off, and the inverter circuit 17 includes diodes Dun, Dvn, Dwn, Dum, Dvm, and Dwm that are connected to the diode bridge 3. The AC power generated in the synchronous generator 1 is charged to the battery 21 as DC power. The operation up to this point is a conventional well-known operation.

The fourth embodiment is characterized in that the transistors Qum, Qvm, Qwm act as the switching means 9 during the above-described power generation operation of the synchronous generator 1. That is, while the transistors Qun, Qvn, and Qwn remain in the off state, the control signal is transmitted from the drive circuit 13 of the control circuit 11 to the resistors Ru,
The transistors Qum, Qvm, Q of the switching means 9 are connected via Rv, Rw and diodes Dup, Dvp, Dwp, respectively.
It is supplied to the base of wm to turn on / off the transistors Qum, Qvm, Qwm. Thereby, the transistors Qum, Qv
When m and Qwm are on, the armature coils 1ub, 1vb, 1w
b, etc., and superimpose the voltage generated in the armature coils 1ua, 1va, 1wa when the diodes Dum, Dvm, Dwm are off and the power stored in the armature coils 1ub, 1vb, 1wb, etc., and output terminals. Output from 19a and 19b. As a result, the battery 21 can be charged, and the circuit operation is the same as that of the first embodiment.

As described above, in the fourth embodiment, the control circuit 11 capable of driving the transistors Qum, Qvm, and Qwm of the transistor portion of the inverter device used for the motor generator operation of the synchronous machine is added only, and the number of parts is reduced. And a power generation characteristic that makes it possible to charge the battery 21 at a low rotation speed.

In each of the above embodiments, the transistors Qu, Qv, and Qw are used as the switching means 9.
Any element that can realize the switching action may be used, and for example, a thyristor (SCR), a gate turn-off thyristor (GTO), or the like may be used.

[0074]

As described above, according to the first aspect of the present invention, the switching means is turned on and off, and the current flowing through the armature coil when the switching means is turned on is given to the armature coil by the switching means. Is stored in the inductance component of the armature coil as electric power and can be superimposed on the generated voltage of the armature coil, so that even when the motor is rotating at a low speed, the output current can be increased with a simple circuit configuration. .

According to the second aspect of the present invention, the on / off control of the switching means is performed at a predetermined rotational speed or less.
Since the switching means is turned off at a predetermined rotation speed or more, a large generated current can be taken out at a predetermined rotation speed or less, and power generation can be performed at the maximum capacity of the generator at a predetermined rotation speed or more.

Further, according to the third aspect of the present invention, the predetermined number of revolutions is defined as an intersection of a characteristic when the switching means is not on / off controlled and a characteristic when the switching means is on / off controlled. In some cases, a large current can be taken out depending on the number of rotations, and when the number of rotations is equal to or higher than the intersection, there is an effect that power can be generated with the maximum capacity of the generator.

According to the fourth aspect of the present invention, the on / off control of the switching means is performed at an on / off ratio that gradually decreases in accordance with the rotation at a predetermined rotation speed or less, and the switching device is turned off at a predetermined rotation speed or more. In this case, the electric current is increased, and when the number of rotations is equal to or more than the predetermined number of revolutions, the electric power can be generated with the maximum capacity of the generator.

According to the fifth aspect of the present invention, the switching means is controlled such that the output characteristic of the generator has the maximum off-time ratio at the number of revolutions in contact with a straight line passing through the origin. There is an effect that a current whose output current increases with the increase of the current can be extracted.

According to the sixth aspect of the present invention, the inverter device used when the generator is used as the motor is also used as the diode bridge and the switching means, and the switching means is controlled to be on / off. There is an effect that the output current can be increased even when the rotation speed is low.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of an automotive alternator according to the present invention.

FIG. 2 is a time chart for explaining the operation of the first embodiment.

FIG. 3 is a characteristic diagram showing a relationship between a current output and a rotation speed of the first embodiment.

FIG. 4 is a circuit diagram showing a second embodiment.

FIG. 5 is a characteristic diagram showing a relationship between a current output and a rotation speed of the second embodiment.

FIG. 6 is a circuit diagram showing a third embodiment.

FIG. 7 is a characteristic diagram showing a relationship between an on / off ratio and a rotation speed of the third embodiment.

FIG. 8 is a characteristic diagram showing a relationship between current and rotation speed in the third embodiment.

FIG. 9 is a characteristic diagram showing a relationship between a current output and a rotation speed of the third embodiment.

FIG. 10 is a circuit diagram showing a fourth embodiment.

FIG. 11 is a circuit diagram showing a conventional automotive alternator.

FIG. 12 is a characteristic diagram showing a relationship between an output current and a rotation speed of a conventional automotive alternator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Synchronous generator 1ua armature coil 1va armature coil 1wa armature coil 1ub armature coil 1vb armature coil 1wb armature coil 2 Field coil 3 Diode bridge 5 Voltage regulator 9 Switching means 11 Control circuit 13 Drive circuit 14 Rotation Detector 15 Rotation speed / voltage conversion circuit 16 Conversion drive circuit 17 Inverter circuit 21 Battery 23 Load Q transistor Qu transistor Qv transistor Qw transistor

Claims (6)

(57) [Claims] 1. A diode bridge means connected between an armature coil of a generator and a battery and comprising a plurality of diode elements for rectifying an AC output from the generator and supplying a DC component to the battery. Switching means connected between the armature coil of the generator and the diode bridge means so as to short-circuit the armature current from the armature coil; and Control means for performing on / off control in a controlled manner, wherein during the on-period of the switching means, the short-circuit current is applied to an armature coil of the generator to accumulate electric power in an inductance component of the armature coil, and the switching is performed. Means for supplying the accumulated power to the battery via the diode bridge means during the off period of the means. Automotive alternator according to claim. 2. The control device according to claim 1, further comprising: a rotation detector that receives a rotation speed signal from the generator, and outputs a signal when the rotation speed of the generator is smaller than a predetermined rotation speed. 2. The alternator for a vehicle according to claim 1, further comprising a drive circuit for turning on / off the switching means in response to the signal. 3. The rotation detector fetches a rotation speed signal from the generator, and the rotation speed from the generator determines an output characteristic when the switching unit is turned on and off and the switching characteristic. 3. The alternator for a vehicle according to claim 2, wherein the circuit is configured to output a signal for operating the drive circuit when the number of rotations is equal to or less than the intersection with the output characteristic when the switch is normally off. 4. The control means captures a rotation speed signal from the generator, and when the rotation speed of the generator is equal to or less than a predetermined rotation speed, turns on / off in response to a continuous change in the rotation speed.
2. The vehicle alternator according to claim 1, wherein said switching means is turned on and off at an on / off ratio in which an off time occupying an off period gradually changes. 5. The control circuit according to claim 1, wherein the control circuit outputs a signal such that an output characteristic of the generator has a maximum off-time ratio at a rotation speed in contact with a straight line passing through the origin. The vehicle alternator according to claim 1 or 4. 6. The switching device according to claim 1, wherein the diode bridge means and the switching means comprise a diode element and a switching means of an inverter device used when the generator is driven as a motor. The alternator for a vehicle according to the above.