JPH01190300A - Power supply device for vehicle - Google Patents

Abstract

PURPOSE:To miniaturize a device and lighten the weight of it, by a method wherein a generator for generating charging DC output and the AC output of high tension is used, wherein the AC output is converted to DC and is converted again to AC and is fed to a load, and wherein voltage is controlled at a section where the AC is converted to the DC. CONSTITUTION:A generator 1 has a DC low-output armature winding 11, and an AC high-tension output armature winding 12. DC low-output generated at the DC low-output armature winding 11 is fed to a load 6 on the DC side via rectifiers 13, 14. AC high-tension output generated at the AC high-tension output armature winding 12 is fed to a load 10 on the AC side via an AC-DC converter 7, a DC-DC converter 8, and a DC-AC converter 9. The DC-DC converter 8 has voltage controlling function.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a power supply device for a vehicle using a generator having a plurality of voltage outputs, and in particular to a commercial AC power supply using a generator for charging an automobile. The present invention relates to a vehicle power supply device suitable for obtaining the following.

[Conventional technology]

In recent years, as the demand for the use of home appliances such as television receivers in automobiles has increased, it has become desirable to install a 100 AC commercial power source in automobiles as well.

Conventionally, as a device for obtaining AC power from the output of a vehicle charging generator, as described in Japanese Utility Model Application Publication No. 156389/1989, the charging DC output of the generator is converted into AC high voltage output using an inverter circuit and a transformer. Alternatively, as described in Japanese Utility Model Application Publication No. 55-87182, two systems are provided for the output terminals of the winding of the charging generator, and the AC power output obtained from one of the output terminals is directly used as an AC power source. The devices used are known.

[Problem to be solved by the invention]

Among the above-mentioned conventional technologies, the device that converts the low-voltage DC output of a generator into high-voltage AC requires a transformer, so it is difficult to reduce the size and weight. Since the current increases at a rate several to several tens of times higher than that, there is also a problem in terms of loss in high-power power supply devices.

On the other hand, in a device that generates two system voltages (DC low voltage and AC high voltage) for the charging system from a generator, there is a risk of mutual interference between the connected outputs of the two systems, especially the effect on the AC output voltage due to changes in the charging system DC output. The problem was that it was big. In other words, if output voltage control of two systems, DC charging system voltage and AC high voltage, is performed by a generator with only one system of field circuit, the DC side that directly controls the voltage will have a constant voltage output, but the AC output The voltage is not determined by the constant voltage output determined by the turns ratio with the armature winding for DC output, but is affected by the field current that is controlled according to the output on the low voltage side, resulting in large changes. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a dual-system power supply device suitable for use in a vehicle, which is small and lightweight, has small changes in output voltage, and is capable of supplying DC constant voltage power and AC constant voltage power.

[Means to solve the problem]

The above purpose is to use a generator that generates a DC output for charging and a high-voltage AC output, and to convert this AC output into DC, and then convert it back into AC and supply it to the load. At this time, this is achieved by performing voltage control on the portion converted to direct current.

[Effect]

The high-voltage AC output of the generator is first converted to DC, and the voltage is controlled in this DC state. After this, the high-voltage AC output that is converted back to AC is controlled by the field of the generator. Despite intensity changes, it can be controlled to a predetermined value.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the vehicle power supply device according to the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, in which 1
is a generator that outputs voltage from two systems, and is driven by an automobile engine via a belt or the like.

Reference numeral 2 denotes a battery, which charges and discharges the power generated by the generator 1 to supply power to the electric load 6 on the DC side.

3 is a key switch; 4 is a charge lamp; this charge lamp 4 lights up when the key switch 3 is closed and the DC generated voltage of the generator 1 is lower than the terminal voltage of the battery 2; The light is turned off when the potential difference between the generated voltage and the battery terminal voltage becomes small.

Reference numeral 5 denotes an initial excitation resistor, which functions to supply an initial excitation current from the battery 2 to the generator 1 when the key switch 3 is turned on.

7 is an AC-DC converter, which is composed of a three-phase full-wave rectifier using diodes.

8 is a DC-DC converter, which includes a power transistor 81, a diode 82, capacitors 84 and 85, and a reactor 83.
By switching the transistor 81 and changing the conduction rate at this time, the diode 82,
The DC output obtained from a smoothing circuit consisting of a capacitor 84 and a reactor 83 is controlled to a constant voltage.

Reference numeral 9 denotes a DC-AC converter, which is composed of a single-phase inverter using a transistor as a main switching element, and functions to supply AC power of a constant frequency and constant voltage to an electric load 10 on the AC side.

Next, the internal circuit and operation of the generator 1 will be explained.

The generator 1 includes an armature winding 11 for direct current low voltage output, and an AC high voltage output I having the number of turns n times the number of turns of this winding 11.
An armature winding in which 1 armature wire 12 is connected in series, and a winding 1
a three-phase full-wave rectifier 13 that converts the AC voltage generated from the AC voltage source 1 into DC; a field winding 15 that supplies magnetic flux to a magnetic circuit consisting of an armature and a rotor; and an exciting current supplied to the field winding 15. Auxiliary diode 14 and voltage regulator 1 for
6. Here, the internal circuit of the voltage regulator 16 is shown in the circuit diagram of FIG. 2, with power transistors 161 . Flywheel diode 162. Control transistor 163. The power transistor 161 is made up of a constant voltage diode 164 and voltage dividing resistors 165 and 166, and the power transistor 161 is energized or cut off depending on the voltage at the terminal a, and controls the current flowing through the field winding 15. It operates to control the voltage generated at the output terminal of the child winding 11 to a constant value.

Therefore, the voltage generated at the output terminal of the armature winding 12 is a constant voltage approximately (n+1) times the voltage of the winding 11. Therefore, the field current flowing through the field winding 15 of the generator 1 is the pre-winding of the electric machine! Since the voltage of the winding 12 is controlled according to the output of the generator 11, the voltage of the winding 12 fluctuates as shown in the output characteristics of the generator 1 shown in FIG.

Therefore, this voltage fluctuation will be explained with reference to FIG. 3, which shows the output characteristics of the generator 1.

In the characteristic diagram shown in Fig. 3, the vertical axis represents the DC voltage after three-phase full-wave rectification of the AC output of winding 11 or 12, and the horizontal axis represents the output current of AC-DC converter 7. In the figure, ■ indicates the output voltage characteristics of the three-phase full-wave rectifier 13, and W, X, and Y indicate the output current of the rectifier 13 of 2 A each.
, 20A, and 40A.

As shown in this figure, when the output terminal voltage on the DC low voltage side (winding 11) is controlled to a constant voltage as shown in characteristic V, when the output current on the low voltage side increases, the voltage regulator 16 In order to compensate for the increase in the potential drop of the output terminal voltage caused by the synchronous impedance rectifier or the like, the field current is increased and the induced electromotive voltage of the armature winding 11 is increased. Therefore, the output voltage of the armature winding 12 will increase even if its output current remains unchanged.

In this way, in the generator 1 that generates dual-system voltage, when the voltage of the charging system is controlled to be constant, the output voltage on the AC high voltage side is subject to large fluctuations depending on the rotation speed and output current of the generator 1. It ends up.

Therefore, in this embodiment, as shown in FIG. The DC voltage is first converted to DC by the DC converter 7, and then the DC voltage is converted to a constant voltage lower than the output voltage of the converter 7 by the DC-DC converter 8 constituted by a step-down switching regulator. The DC output of the DC-DC converter 8 is The voltage, that is, the DC input voltage of the DC-AC converter 9 is always kept at a constant value,
As a result, fluctuations in the AC voltage supplied to the high-voltage AC electrical load 10 can be sufficiently suppressed.

Note that when AC power is supplied using a DC-AC converter consisting of an inverter circuit, it is necessary to use the DC-DC converter 8 to maintain the DC input voltage at a constant value, as in the above embodiment. Even without control, it is possible to control the AC output voltage and maintain it at a predetermined value by adjusting the conduction rate of the inverter circuit. however,
In this way, by simply adjusting the conduction rate of the inverter circuit,
By controlling the AC output voltage, the average value or effective value of the AC output voltage can certainly be kept constant, but the peak voltage of the AC applied to the electric load 10 is affected by the AC-DC converter 7. It is always the same as the output voltage. Therefore, when the AC output voltage of the generator 1 fluctuates, there is a possibility that a high voltage exceeding the rated peak voltage will be applied to the electrical load 10.

According to the above embodiment, the DC-DC converter 8 is provided, and the DC input voltage of the DC-AC converter 9 is controlled to a predetermined value in advance. It is possible to sufficiently suppress the occurrence of a situation in which a voltage with a peak value that exceeds the peak value is applied.

Further, according to this embodiment, by providing the DC-DC converter 8, the rated voltage of the semiconductor switching element used in the DC-AC converter 9 and the rated voltage of components such as the output terminal can be adjusted. If not, it can be lower.

Incidentally, in the embodiment shown in FIG. 1, the AC-DC converter 7 is provided outside the generator 1, but it is also possible to install it inside the generator 1. Further, although the semiconductor switches of the DC-DC converter 8 and the DC-AC converter 9 are configured using transistors, other semiconductor elements such as FETs and SIRIS may also be used.

In this case, there is an effect of increasing the operating frequency and increasing the withstand voltage.

Next, another embodiment of the present invention will be described with reference to FIG.

In this FIG. 4, 1 is a generator, and in this embodiment, the armature winding 11 for outputting charging system voltage and the armature winding 12 for outputting AC high voltage system voltage are electrically insulated, and , each having armature windings independently forming a three-phase star winding.

80 is a DC-DC converter using a step-up switching regulator, and transistors 81 . Diode 82.
It is composed of a reactor 83 and a capacitor 84.

In this embodiment, since the DC-DC converter 80 is constituted by a step-up switching regulator, the winding w
Since the voltage generated at A12 can be lower than the predetermined output voltage of the power supply device, it is possible to reduce the number of turns of the winding 12.

Further, in the DC-DC converter 80 consisting of this step-up switching regulator, there is no need to provide a smoothing capacitor at its input terminal, so the transistor 81
By setting the switching frequency to a sufficiently high value, harmonic components of the output current of the 12 turns can be suppressed. Note that, in a device that requires a large-capacity capacitor 85 after the AC-DC converter 7 consisting of a rectifier circuit, as in the embodiment shown in FIG. The result is a distorted waveform that contains a lot of
In a power supply device in which a DC-DC converter 80 using a step-up switching regulator is provided after a rectifier circuit as in the embodiment shown in FIG. This is because the waveform can be made closer to the wave current.

According to the embodiment shown in FIG. 4, the charging voltage system and the AC high voltage system are electrically insulated, and as described above, the harmonic components of the output current of the generator 1 on the high voltage side are sufficiently suppressed. Therefore, it is possible to reduce the influence from the AC high voltage side on the charging system that serves as a power source for electronic control devices, etc. in automobiles, etc., and it is possible to suppress noise interference to electronic control devices, etc.

By the way, in such a power supply device, for example, a circuit capable of controlling the DC output voltage using a phase control element is provided as the AC-DC converter 7 in the embodiment shown in FIG. One possible method is to omit the container 8.

However, since the vehicle charging generator is driven by the engine of the automobile, its driving rotation speed and, by extension, the frequency of its AC output vary significantly.

Therefore, in such a case, if the AC-DC converter 7 were to control the DC output voltage by phase control as described above, the control content would become complicated and problems such as commutation failure would occur. This also increases the number of occurrences, leading to problems such as decreased reliability.

However, according to the above embodiment, the DC-DC converter 8,
Alternatively, 80 is provided, thereby controlling the voltage in the DC portion, so there is no risk of malfunction and high reliability can be easily maintained.

In addition, in the above embodiment, the DC-DC converter 8 or 8
The DC voltage is controlled by 0 so that the output voltage is kept at a predetermined constant value. You may.

〔Effect of the invention〕

According to the present invention, vehicle charging is started! In a power supply device that generates two systems, a DC low-voltage power supply for a charging system and an AC high-voltage constant voltage power supply, using one unit, it is possible to improve the constant voltage controllability of the output voltage, and it is also possible to reduce the size and weight.
This has the effect of maintaining the reliability of electrical loads and providing a power supply device suitable for use in vehicles.

Furthermore, according to the present invention, the peak value of the AC voltage supplied to the electrical load on the AC high voltage side is controlled to be below a certain value, so that a high voltage exceeding the rating is not applied to the electrical load. Furthermore, since the alternating current high voltage is generated by a generator, there is no need to use a step-up transformer, so there is an effect that the power supply device can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of a vehicle power supply device according to the present invention, FIG. 2 is a circuit diagram showing an example of a voltage regulator, and FIG. 3 is a circuit diagram showing an example of a voltage regulator.
The figure is a characteristic diagram of the generator, and FIG. 4 is a circuit diagram showing another embodiment of the present invention. 1.--. Generator, 2.--.1.-. Battery, 3.
−・−−−−Key switch, 4−・−Charge lamp, 5・−−−1−−Resistor for initial excitation, 6−−−−−
---Electrical load on the DC side, 7--AC-DC converter, 8, 80...-DC-DC converter, 9-----
・DC-AC converter, 10----- Electric load on the AC side. Decoration Figure 2 7. Traffic, engineering, 8 years history

Claims (1)

[Claims] 1. A power generator for a vehicle that has an armature winding that generates two types of output voltages, one on the low-voltage side and one on the high-voltage side, and has a function of controlling the excitation intensity according to the output voltage on the low-voltage side. In the machine, an AC-DC converter inputs the output voltage of the high voltage side, and the AC-
A vehicle power supply characterized in that a DC-DC converter is provided between a DC-AC converter that receives the output of the DC converter as an input, and the DC-DC converter is configured to have a voltage control function. Device. 2. The vehicle power supply device according to claim 1, wherein the DC-DC converter is comprised of a switching regulator.