JPH0570371B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is capable of outputting voltage-controlled alternating current or voltage-controlled direct current by using one regulator. This invention relates to a vehicle alternator.

[Conventional technology]

A vehicle alternator is, for example, a three-phase alternating current generator.When supplying to an alternating current load, it supplies the generated alternating current as it is, and when supplying to a direct current load, it rectifies the generated induced voltage and charges a battery. Supply through. The battery voltage is usually lower than the AC load voltage (e.g.
Since the AC load voltage is 55V and the battery voltage is 12V, the DC output is used by rectifying the induced voltage taken from the middle of the generator winding.

To control the output voltage using a single regulator, install a voltage division ratio switching circuit where the detected voltage is input to the regulator to handle the difference in voltage between AC output and DC output. to switch the partial pressure ratio.

[Problem that the invention seeks to solve]

In the conventional vehicle alternator described above, one regulator is used, so by switching the voltage division ratio, only one type of output can be obtained at a time, such as only AC if it is AC, or only DC if it is DC. Nakatsuta. However, in recent years, there has been a growing desire to simultaneously charge a battery and supply power to a DC load even when supplying power to an AC load. Conventional vehicle alternators have had the problem of not being able to meet such demands.

[Means for solving problems]

In order to solve the above problem, the present invention provides a battery charging method in which a tap is provided in the generator winding at a lower position than the tap used for DC output, and the induced voltage taken out from this tap is rectified and charged to the battery. A rectifier circuit was installed for

〔Example〕

FIG. 1 shows an embodiment of the present invention.

(A) About the circuit configuration In Figure 1, 1 is an alternator, 2-1 to 2-3 are power generation windings, 3 is a field winding, 4-1,
4-2 is an auxiliary winding, 4-3 is an excitation auxiliary winding,
5 and 6 are rectifier circuits, 7 is a regulator, 8 is a diode, 9 is an AC load, 10 is a battery, 11 to 13 are switches, 18 is a rectifier circuit, 19 is a capacitor, 20 to 25 are resistors, 26 is a switch, 27 28 is a DC conversion circuit, 28 is a battery charging rectifier circuit, 29 is a switch, TR ₁ to TR ₃ are transistors, and D _Z is a constant voltage diode.

An overview of the circuit configuration will be explained.

Three-phase power generation windings 2-1 and 2 of alternator 1
-2 is wound with auxiliary windings 4-1 and 4-2 in a corresponding manner, and a 3-phase power generation winding 2-3 is wound with an excitation auxiliary winding 4-3 in a corresponding manner. There is. The auxiliary windings 4-1, 4-2 are the auxiliary windings 4-1, 4-2.
The three-phase power generation windings 2-1 and 2-2 are connected in series so that the voltages generated at the windings 4-2 are added to the voltages of the corresponding three-phase power generation windings 2-1 and 2-2. The boosted voltage of the V-connection taken out from each end X, Y connected in series is applied to the AC load 9 via the switch 11. The generated voltage is rectified by a rectifier circuit 5 and supplied to a DC load via a battery 10 . The power generation voltage is controlled by controlling the field current. The field current is controlled by turning on and off the transistor _TR3 in the regulator 7.

The excitation auxiliary winding 4-3 is provided to cope with the case where the AC load 9 has a large capacity, such as a heater, and requires a large output from the alternator 1. Excitation auxiliary winding 4-3
The voltage generated is input to the DC conversion circuit 27. If the AC load 9 requires a large output, the switch 26 is turned on. Then, the DC voltage converted by the DC conversion circuit 27 is applied to the field winding 3 via the switch 26, and a new field current is added to the field current supplied from the rectifier circuit 6. Therefore, it is possible to cope with large output.

The battery charging rectifier circuit 28 is used to simultaneously charge the battery 10 with a controlled voltage during AC output and also supply power to a DC load, and is a feature of the present invention.

(B) About circuit operation Next, we will divide the operation of this vehicle alternator into operation at startup, operation when only DC output, operation when only AC output, and operation when simultaneous output of DC and AC. explain.

(B-1) Operation at startup The system is started by performing initial excitation using the battery 10, and then transitioning to self-excitation type excitation when the voltage of the alternator 1 increases.

Turn on switch 12. Current flows from the battery 10 to the resistors 21 and 22 via the diodes 8 and 15. In this case, the values of the circuit elements are selected so that the voltage across the resistor 22 is a voltage that does not turn on the constant voltage diode _DZ . Since the constant voltage diode D _Z is off, the transistor TR ₁ is also off. Therefore, current flows from the battery 10 through the diode 8, the resistor 23 in the regulator 7, and the bases and emitters of the transistors TR ₂ and TR ₃ , turning on the transistor TR ₃ . Then, a field current flows from the battery 10 to the field winding 3 via the diode 8. Initial excitation is performed by this field current. As the alternator 1 rotates, the generated voltage gradually increases. The generated voltage is rectified by a rectifier circuit 6. In the phase where the rectified voltage is still lower than the voltage of the battery 10, the diode in the rectifier circuit 6 is reverse biased and no current flows. but,
When the rectified voltage of the rectifier circuit 6 becomes higher than the voltage of the battery 10, the diode 8 is reverse biased and turns off, while the diode in the rectifier circuit 6 turns on. Therefore, from this point on, the field current to the field winding 3 and the operating current of the regulator 7 are supplied exclusively from the rectifier circuit 6. The startup is thus completed. The operation at startup is the same whether it is DC output or AC output.

(B-2) Operation when using only DC output When supplying power only to a DC load, after startup,
First, switch 13 is turned on. switch 11,1
6, 17, 26, and 29 remain off. At this time, the generator windings 2-1 to 2-3 of the alternator 1
The AC voltage taken out is rectified by the rectifier circuit 5, and is supplied to the DC load while charging the battery 10.

Voltage control is performed as follows. The AC voltage obtained from the power generation windings 2-1 to 2-3 is also rectified by the rectifier circuit 6. This rectified voltage is used as a field voltage and also as a voltage for output voltage detection. That is, it is applied to the field winding 3 and also to the resistors 21 and 22 via the diode 15. Resistors 21 and 22 divide the output voltage, and the voltage across resistor 22 is used for detection. Since the waveform of the voltage across the resistor 22 is a rectified three-phase sine wave, it rises and falls with time. Therefore, the voltage regulator diode D _Z is turned on only during the period when the constant voltage defined by the voltage regulator diode D _Z is exceeded. If the output voltage is large, the voltage across the resistor 22 will also be large, and the time the voltage regulator diode D _Z is turned on will also be long. When the constant voltage diode D _Z turns on, the transistor TR ₁ also turns on, and the transistor
Since TR ₃ is turned off, the longer the voltage regulator diode D _Z is on, the more the transistor
The time that TR ₃ is off also increases. Therefore,
The current flowing through the field winding 3 decreases. As a result, the output voltage decreases and is pulled back to a predetermined value.
Conversely, when the output voltage becomes small, the time during which the transistor TR ₃ is off becomes shorter, and the field current becomes larger. As a result, the output voltage increases and is also pulled back to a predetermined value.

(B-3) Operation when using only AC output When supplying power only to AC load, after startup,
Turn on switches 11, 16, and 17. Switch 13 is turned off. Since the voltage required by the AC load 9 is generally higher than the voltage of the DC load, the auxiliary windings 4-1 and 4 are connected to the voltage of the power generation windings 2-1 and 2-2.
-2 voltages are added respectively. A so-called V-connection system is used, and the power is supplied from both ends X and Y to the AC load 9 via the switch 11. Voltage control is performed as follows. The DC voltage proportional to the AC output voltage obtained from the AC voltage detection circuit 14 is
It is applied to the resistive voltage divider circuit of the regulator 7 via the switch 17. The voltage division ratio during DC load is resistance 21
However, since switch 16 is turned on during AC load, the resistance value of resistor 21 is the ratio of the resistance value of resistor 21 and the parallel combined resistance value of resistors 22 and 20. The divided voltage is passed through the constant voltage diode D _Z
is compared with a constant voltage of , and turns on transistor TR ₁ when it is greater than that. Thereafter, the field current is turned on and off in the same manner as the control operation during DC load, and the generated voltage is controlled.

The reason why the resistor 20 is connected in parallel to the resistor 22 is to reduce the voltage division ratio with the resistor 21. Since one regulator 7 is used for both purposes and the magnitude of the voltage is compared with the same constant voltage diode D _Z , the voltage appearing across the resistor 22 is made to be about the same magnitude even when an AC load is applied as when it is a DC load. There is a need. However, the voltage required for AC loads (e.g.
55V) is the voltage required for DC load (e.g. 12V)
larger than Therefore, it is necessary to reduce the partial pressure ratio during AC loads. In FIG. 1, the resistor 20 and the switch 16 are connected in parallel with the resistor 22, and the switch 16 is turned on when an AC load is applied.
Although the switch 16 is turned off when a DC load is applied, it may be connected in parallel with the resistor 21 so that the switch 16 is turned off when an AC load is applied and turned on when a DC load is applied. Even with this, the partial pressure ratio at AC load is
It can be made smaller than that under DC load.

Note that if the AC load 9 is a load that produces a large output, such as a heater, the switch 26 is turned on to strengthen the field. Excitation auxiliary winding 4
The alternating current generated at -3 is converted into direct current by the direct current conversion circuit 27 and supplied to the field winding 3. In addition to the current from the rectifier circuit 6, the current from the DC conversion circuit 27 also flows through the field winding 3, so that the field is further strengthened.

(B-4) Operation during simultaneous AC/DC output After startup, turn on switches 11, 16, 17, 29 and, if necessary, switch 26. Control of the AC output voltage is performed as described in section (B-3). For DC load, battery charging rectifier circuit 2
8. Electric power is supplied through the switch 29 and the battery 10, and the DC output voltage is controlled as follows.

The alternating current taken out from the taps of the power generation windings 2-1 to 2-3 is input to the battery charging rectifier circuit 28. Since the AC output voltage to the AC load 9 is controlled to be constant as described above, the AC voltage taken out from the tap is also a constant voltage determined depending on the position of the tap. Therefore, the position of the tap is selected so that the constant voltage matches the voltage required by the DC load. Then, along with the control of the AC output voltage, the DC output voltage is also automatically controlled.

Since the output voltage of the rectifier circuit 5 is automatically controlled by the same logic, the question immediately arises as to whether it would be better to supply it from here. However, this one is too big and no good. The reason is as follows. The input AC to the rectifier circuit 5 is the power generation winding 2-1.
It is taken out from 2-3. The input AC voltage is determined when the circuit configuration of the regulator 7 is in a position to control only the DC output (that is, when the switch 16
The output voltage of the rectifier circuit 5 is selected to be a voltage suitable for the DC load when the output voltage is off and the resistor 20 is disconnected. Therefore, the circuit configuration surrounding the regulator 7 is set to AC output control (that is, the switch 16 is on and the resistor 20 is connected in parallel to the resistor 22), and the generated voltage becomes a voltage suitable for the AC load 9. When the voltage rises to such an extent, the voltage at the winding position from which the AC input to the rectifier circuit 5 was taken also rises, and the voltage is no longer suitable for a DC load.

That is, under the operating state of AC/DC simultaneous output, the voltage from the AC voltage detection circuit 14 is applied to the constant voltage diode _DZ with the voltage division ratio adjusted by the resistor 20.

Under such voltage adjustment conditions, supplying the desired voltage to the AC load,
Such a tap position that can also supply a desired voltage to a DC load is the tap position that supplies the battery charging rectifier circuit 28.
That is, these are the tap positions provided in the power generation windings 2-1 to 2-3. The output voltage of the rectifier 5 under this condition is too high. The reason for this is that the output voltage of the rectifier 5 has a value suitable for the power supply voltage to the DC load when the voltage is applied to the constant voltage diode D _Z without using the resistor 20. It is from.

In addition, the voltage division ratio in the AC voltage detection circuit 14 in the case of operation with only an AC load is selected and designed so that the divided voltage matches the output voltage of the diode 15 in the case of operation with only a DC load. () AC voltage detection circuit 1
The partial pressure ratio at 4 becomes too small,
() This is not sufficient because the output voltage of the diode 15 under operation with simultaneous AC and DC outputs does not necessarily match the output voltage of the diode 15 under operation with only a DC load.

〔Effect of the invention〕

As explained above, according to the present invention, in an alternator that also serves as one regulator and outputs controlled alternating current or direct current, by simply adding a simple circuit called the battery charging rectifier circuit 28,
The battery can now be charged even during AC output.

[Brief explanation of the drawing]

FIG. 1 shows the configuration of an embodiment of a vehicle alternator according to the present invention. In the diagram, 1 is an alternator, 2-1 to 2-3
is a power generation winding, 3 is a field winding, 4-1 and 4-2 are auxiliary windings, 4-3 is an excitation auxiliary winding, 5 and 6 are rectifier circuits, 7 is a regulator, 8 is a diode, 9 is an AC load, 10 is a battery, 11 to 13 are switches, 18 is a rectifier circuit, 19 is a capacitor, 2
0 to 25 are resistors, 26 is a switch, 27 is a DC conversion circuit, 28 is a rectifier circuit for battery charging, 2
9 is a switch, TR ₁ to TR ₃ are transistors,
D _Z represents a constant voltage diode.

Claims (1)

[Scope of Claims] 1. A generator winding configured to supply power to an AC load at a higher voltage, and to supply power to a single DC load at a lower voltage while charging a battery; selectively switching the output voltage from the switch between a state in which power is supplied to the AC load and a state in which power is supplied to the DC single load, and when power is supplied to the AC load and when power is supplied to the DC single load. In a vehicle alternator configured to apply an input voltage to a single regulator by switching the voltage division ratio when power is supplied to the generator, and to control the generated voltage respectively by using the single regulator, An intermediate tap is provided in the generator winding of the alternator, and a rectifier circuit for battery charging is provided to rectify the voltage from the intermediate tap, and a power supply circuit is provided to supply power to the single DC load when power is supplied to the AC load. After the battery is disconnected, the output voltage from the battery charging rectifier circuit can be supplied to the battery via a switch means, and the DC power can be supplied to the single load and the AC load can be supplied separately. An alternator for a vehicle, characterized in that an AC/DC simultaneous power supply state in which power is supplied to the AC load and a simultaneous AC/DC power supply state in which power is supplied to the DC load while charging the battery is selected by the switch means.