JP2835096B2 - Power supply for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a vehicle that switches a three-phase full-wave rectified voltage and supplies power to a battery and a different voltage load driven by a different voltage from a battery. .

[Related Art] In recent years, a technique has been proposed in which a transparent resistor is vapor-deposited on a window glass of an automobile, and this resistor is electrically heated to remove ice and frost attached to the glass at high speed. It is necessary to transmit a large amount of power to this resistor in order to shorten the time of defrosting and defrosting, but due to transmission loss and the allowable current of the generator and rectifier, the resistor is much more than the battery charging voltage. It is required to apply a high voltage.

Japanese Patent Publication No. 61-33735 discloses such an output voltage switching type vehicle power supply device. This vehicle power supply device includes a three-phase full-wave rectifier configured by three sets of half-bridge circuits.
It is composed of a set of lower half bridge circuits and two sets of higher half bridge circuits. Each anode of the lower half-bridge circuit is grounded, and each cathode is individually connected to each output terminal of the three-phase AC generator. Each anode of the first higher half-bridge circuit is individually connected to each output terminal of the three-phase AC generator, and each cathode thereof is commonly connected to switch the battery to the positive terminal of the battery or the high potential terminal of the resistor. It is selectively connected via a switch. Second
Are connected individually to respective output terminals of the three-phase AC generator, and their respective cathodes are commonly connected to a field coil of the generator via a changeover switch. The lower electrode ends of the battery and the resistor are grounded.

[Problems to be Solved by the Invention] However, in the above-described conventional power supply device for a vehicle,
There were the following problems.

First, the vehicle power supply is in a harsh environment in terms of heat and vibration, and it is important to reduce the causes of failures as simple as possible. 3) As compared with a dedicated power supply device for a vehicle, there is a disadvantage that an extra resistor changeover switch and a battery changeover switch must be prepared and wired.

Also, the charging line connecting the three-phase full-wave rectifier consisting of each half-bridge circuit and the battery needs to have a low resistance in order to reduce the power loss and heat generation. If interposed, the wiring becomes longer by that amount, and the resistance increases due to the contact resistance between the charging line and the terminal of the battery changeover switch. In addition, there is a possibility that the battery changeover switch may fail or the terminal may become loose.

The present invention has been made in view of the above problems, and provides a power supply device for a vehicle having a simple configuration and high reliability, while switching and supplying power to a battery and a different voltage load by switching a three-phase full-wave rectified voltage. It is a problem to be solved.

Means for Solving the Problems To solve the above problems, the present invention relates to a vehicle power supply device for a vehicle having a vehicle battery and a different voltage load having a rated voltage different from the battery. A three-phase alternating current generator driven by a three-phase alternating current generator, a different voltage load switch for interrupting the supply of current to the different voltage load, and rectifying an alternating current output of the three phase alternating current generator to supply the rectified output to the battery and the different voltage load. A rectifier circuit that performs power supply to the battery and a voltage adjuster that changes a power generation voltage of the three-phase AC generator when power is supplied to the different-voltage load. High half bridge including a semiconductor switching element that is individually connected to each output terminal of the power supply and supplies a rectified output to both the positive terminal of the battery and the high potential terminal of the different voltage load. A rectifier circuit; a lower side for different voltage load including a semiconductor switching element that is individually connected to each output terminal of the three-phase AC generator and supplies a rectified output to a non-grounded lower potential side electrode terminal of the different voltage load. A half-bridge rectifier circuit, and a lower half-bridge rectifier circuit for a battery including a semiconductor switching element that is individually connected to each output terminal of the three-phase AC generator and supplies a rectified output to a grounded negative terminal of the battery. At least a semiconductor switching element of the lower half-bridge rectifier circuit for a battery is constituted by a semiconductor switching element with an external control input that can be switched by an external signal, and the external control input corresponding to a power supply request to the different voltage load. A state in which an external control signal to the semiconductor switching element is changed so that power can be supplied only to the battery. Adopt the technical means of the vehicle power supply apparatus characterized by comprising providing a control circuit for switching the power supply working state to a different voltage load.

[Operation] According to the present invention described above, at the time of charging the battery,
The different-voltage load switch is turned off, the power output of the three-phase AC generator is adjusted to the battery charging voltage by the voltage regulator, and the semiconductor switching element with the external control input of the lower half-bridge rectifier circuit for the battery is controlled by the control circuit. Rectifies the output of the three-phase alternator controlled by
The battery is charged.

On the other hand, when driving the different voltage load, the different voltage load switch is turned on to form a power supply path to the different voltage load,
The power output of the three-phase AC generator is adjusted to the rated voltage of the different voltage load by the voltage regulator, and the semiconductor switching element with the external control input of the lower half-bridge rectifier circuit for the battery is controlled by the control circuit. The output of the three-phase AC generator is rectified and supplied to the voltage load from the lower half bridge rectifier circuit for the different voltage load.

[Example] Hereinafter, an example to which the present invention is applied will be described. In the embodiment described below, a high-order half-bridge rectifier circuit is configured by a half-bridge circuit configured by using a silicon diode as a semiconductor switching element, and is configured by using an SCR as a semiconductor switching element. A power supply device is constructed by forming a lower half-bridge rectifier circuit by the half-bridge circuit and its control circuit. In addition, as a semiconductor switching element with an external control input, the gate terminal is used as an external control input.
SCR is used.

First Embodiment As shown in FIG. 1, this vehicle power supply device includes a three-phase AC generator 1 driven by a vehicle engine, a high-order half-bridge circuit 2, a low-order half-bridge circuit 3,
4, a changeover switch 5 constituting a different voltage load switch according to the present invention, a voltage regulator 6, and a gate control circuit 7. Note that each of the half-bridge circuits 2,
3 and 4 and the gate control circuit 7 are integrated with the three-phase AC generator (alternator) 1.

Each output terminal of the stator coil 11 of the three-phase AC generator 1
Each anode of the higher half bridge circuit 2 and each cathode of the lower half bridge circuits 3 and 4 are individually connected to each other, and the higher half bridge circuit 2 and the lower half bridge circuit 3 are composed of silicon diodes. The lower half bridge circuit 4 includes SCRs 41, 42, and 43. Each anode of the half bridge circuit 2 is connected to the positive terminal 80 of the battery 8, and the ground negative terminal of the battery 8 is grounded. The first vehicle load 8a driven by the battery 8 is connected in parallel with the battery 8,
The positive electrode terminal 80 is connected to the high-side electrode terminals of the second vehicle load 9 and the high-voltage load 10. Each lower electrode end of both loads 9 and 10 is individually connected to switching terminals 5a and 5b of the changeover switch 5, and a common terminal of the changeover switch 5 is connected to each anode of the lower half bridge circuit 3.

The high-voltage load 10 is constituted by a vehicle window deicing device made of a thin-film resistance element having a rating of 75 V, and the second vehicle load 9 and the first vehicle load 8 a are rated at a battery voltage of 12 V. The changeover switch 5 has a neutral position together with the changeover terminals 5a and 5b.

The anodes of the SCRs 41 to 43 constituting the lower half bridge circuit 4 are grounded, and their gates are individually connected to the respective output terminals of the gate control circuit 7.

The gate control circuit 7 has an emitter connected to the positive terminal of the battery 8.
It has a PNP transistor 71 connected to 80, and its base is connected to a positive terminal 80 (more precisely, a high potential line HL) of a battery 80 via a high-side base bias resistor 72.
The base is grounded via a low-side base bias resistor 14 and a switch 13. The collector of the transistor 71 is commonly connected to the respective anodes of the diodes 73 to 75, and their respective cathodes are connected to current limiting resistors 76 to 78, respectively.
Are individually connected to the gates of the SCRs 41 to 43.

The high potential line HL is connected to the high end of the field coil 12 of the three-phase AC generator 1 and the high power supply end B of the voltage regulator 6, and the low end of the field coil 12 is connected to the output terminal F of the voltage regulator 6. It is connected to the. Further, the ground terminal E of the voltage regulator 6 is grounded, the input terminal S1 of the voltage regulator 6 is connected to the positive terminal 80 of the battery 8, and the input terminal S2 of the voltage regulator 6 is connected to the low potential of the high potential load 10. It is connected to the side electrode end 10a.

 Hereinafter, the operation of the vehicle power supply device will be described.

At first, the changeover switch 5 is in the neutral position and the switch 13
Are conducting.

The high side base bias resistor 72
The transistor 71 is turned on by the base bias voltage divided by the low-side base bias resistor 14 and the SCRs 41 to 4 via the diodes 73 to 75 and the current limiting resistors 76 to 78.
A predetermined positive voltage is applied to 3 and the gate /
Conduction is periodically conducted from a forward bias between the cathodes. When the SCRs 41 to 43 are periodically turned on, the three-phase AC voltage output from the stator coil 11 of the three-phase AC generator 1 is full-wave rectified by the higher half bridge circuit 2 and the lower half bridge circuit 4, and 8 and the first vehicle load 8a. The voltage regulator 6 detects the voltage of the positive terminal 80 of the battery 8 at the input terminal S1, controls the duty ratio of the field current, and keeps the battery charging voltage supplied to the positive terminal 80 of the battery 8 constant. At this time, the voltage of the input terminal S2 of the voltage regulator 6 becomes the same potential as that of the input terminal S1, and there is no problem.

Next, when energizing the high-voltage load 10, the switch 13 is turned off. When the switch 13 is turned off, the transistor 71 is turned off, the gate current to the lower half-bridge circuit 4 is cut off, and the SCRs 41 to 43 are turned off by releasing the forward bias between the cathode and the gate, and the battery 8 and the first vehicle load are turned off.
8a is disconnected from the three-phase alternator 1. Next, when the changeover switch 5 is operated to connect the high-voltage load 10 to the low-order half-bridge circuit 3, the voltage subjected to full-wave rectification by the half-bridge circuit 2 and the low-order half-bridge circuit 3 is applied to the high-voltage load 10. You. At this time, due to the voltage drop of the high voltage load 10, a low voltage is supplied to the input terminal S2 of the voltage regulator 6 from the lower electrode end 10a of the high voltage load 10,
Increases the duty ratio of the field current to almost 1 in an attempt to restore the voltage of the input terminal S2 to the original voltage, that is, the battery charging voltage. As a result, the stator coil 11 generates a large voltage. When this large voltage is applied to the high-voltage load 10, the lower-side electrode terminal of the high-voltage load 10
10a has a lower potential.

When the switch 5 is turned to the side 5b when the lower half-bridge circuit 4 is turned on, the battery 8 and the first vehicle load are turned off.
8a and the second vehicle load 9 can be driven in parallel.

 Hereinafter, effects of the vehicle power supply device of the present embodiment will be described.

(A) The anodes of the SCRs 41 to 43 are commonly connected, and
The connection is very easy because it is grounded. That is, since the SCRs 41 to 43 are usually fixed to the substrate on the anode side, a grounded metal substrate which also serves as a radiation fin can be directly used as the ground electrode of the half bridge circuit 4. By doing so, the anode wiring of the SCRs 41 to 43 can be omitted, and there is no need to insulate the metal substrate which also serves as the large-area heat radiation fin.

(B) Since the half-bridge circuit 4 is also provided integrally with the three-phase AC generator 1 together with the half-bridge circuits 2 and 3, the length of the three-phase line connecting the stator coil 11 and the half-bridge circuit 4 is reduced. The power loss can be reduced. Further, the gate control circuit 7
Is also integrated with the three-phase alternator (alternator), so that the gate control circuit 7 and the half-bridge circuit 4
Can be shortened.

(C) The vehicle load is distinguished into a first vehicle load 8a whose lower end is grounded and a second vehicle load 9 whose lower end does not need to be grounded. Since power is supplied from the SCR 3, each SCR of the half bridge circuit 4 can be downsized.

Note that the half bridge circuit 4 is replaced with the half bridge circuit 3
Similarly, the half bridge circuit 4 can be grounded via one SCR. However, in this case, the number of parts increases and the lower half bridge circuit 4 And the forward bias voltage drop of the one SCR, the first
There is a disadvantage that the applied voltage differs between the vehicle load 8a and the second vehicle load 9. Also, even if a part of the three SCRs 41 to 43 fails and becomes non-conductive, battery charging can be continued by the remaining SCRs, and there is little possibility that the battery will run out.

(D) The voltage regulator 6 has two input terminals S1 and S2, and preferentially uses the lower input terminal potential for control.
The voltage regulator 6 can be configured by making only a slight change to the conventional one-input terminal type voltage regulator, and there is no need to input a signal such as a load switching signal to the voltage regulator 6.
FIG. 2 shows an example of the configuration of the voltage regulator 6. The resistor R1 has a relatively high resistance, and the potential of the contact S is obtained by adding the forward bias potential of the diode 101 or 102 to the lower potential of the inputs S1 and S2. And the resistance R2 is higher resistance,
The potential of the input terminal S0 is substantially equal to the lower potential of the input terminal S1 or S2. However, when the input terminal S2 has a negative potential, the potential of the input terminal S0 is 0V. Reference numeral 60 denotes a normal one-input terminal type voltage regulator, and reference numeral 100 denotes a level shift diode.

 FIG. 3 shows a modification of the gate control circuit 7.

In the gate control circuit shown in FIG.
When a through 71c are turned on, the SCRs 41a through 41c are shut off, and when they are opened, the SCRs 41a through 41c are turned on. 79 is a current limiting resistor.

Second Embodiment Another embodiment of the present invention is shown in FIG.

This power supply device for a vehicle includes a three-phase AC generator 1, half-bridge circuits 2, 3a and 4, and a voltage regulator 6,
Half bridge circuit 3a is composed of SCR and changeover switch 5
Is different from the first embodiment. Note that the second vehicle load 9 of the first embodiment is omitted.

The half-bridge circuit 4 is controlled by the same gate control circuit (not shown) as the gate control circuit 7 of the first embodiment, and the half-bridge circuit 3a is operated by a gate control circuit that operates in reverse to the gate control circuit 7 of the first embodiment. It is controlled by a circuit (not shown).

By doing so, the circuit configuration can be further simplified, and power transmission to the battery 8 and the high-voltage load 10 can be frequently switched.

[Effect of the Invention] As described above, according to the vehicle power supply device of the present invention, the lower half bridge rectifier circuit for the different voltage load and the lower half bridge rectifier circuit for the battery are provided, and the lower half bridge rectifier circuit for the battery is provided. Since the half-bridge rectifier circuit is composed of a semiconductor switching element with an external control input and its control circuit, the control circuit can control the lower half-bridge rectifier circuit for the battery, and an intermittent switch dedicated to the battery is connected to the battery. Charging from the three-phase AC generator to the battery can be controlled in response to a power supply request to a different voltage load without intervening in a power supply path to the battery. For this reason, the configuration of the vehicle power supply device that can switch between power supply to only the battery and power supply to the different voltage load can be simplified, and reliability and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram showing one embodiment of a vehicle power supply device of the present invention, FIG. 2 is a block diagram of one embodiment of a voltage regulator 6,
FIG. 3 is an equivalent circuit diagram showing a modification of the gate control circuit 7, and FIG. 4 is an equivalent circuit diagram showing another embodiment of the vehicle power supply device of the present invention. DESCRIPTION OF SYMBOLS 1 ... Three-phase alternating current generator 2 ... Higher half bridge circuit 3 ... Lower half bridge circuit 4 ... Lower half bridge circuit 5 ... Changeover switch 6 ... Voltage regulator 7 ... Gate control circuit 8 …… Battery 10 …… High voltage load (different voltage load)

Continuation of the front page (72) Inventor Hiromichi Shigenobu 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-63-253898 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02P 9/00-9/48 H02M 7/00-7/40

Claims (4)

(57) [Claims] 1. A vehicle power supply device for a vehicle having a vehicle battery and a different voltage load having a rated voltage different from the battery, comprising: a three-phase AC generator driven by a vehicle engine; A different-voltage load switch for interrupting the current supply to the battery; a rectifier circuit for rectifying an AC output of the three-phase AC generator and supplying the rectified output to the battery and the different-voltage load; A voltage adjusting means for changing a generated voltage of the three-phase AC generator when power is supplied to a load, wherein the rectifier circuit is individually connected to each output terminal of the three-phase AC generator, A high-order half-bridge rectifier circuit including a semiconductor switching element that supplies a rectified output to both the extreme and the high-potential-side electrode terminal of the different-voltage load, and individually connected to each output terminal of the three-phase AC generator. A low-voltage half-bridge rectifier circuit for a different voltage load that includes a semiconductor switching element that supplies a rectified output to an ungrounded low-potential electrode terminal of the different voltage load, and to each output terminal of the three-phase AC generator. A low-side half-bridge rectifier circuit for a battery that includes a semiconductor switching element that supplies a rectified output to the grounded negative terminal of the battery, wherein at least the semiconductor switching element of the low-side half-bridge rectifier circuit for the battery is externally connected. A semiconductor switching element with an external control input that can be switched by a signal, and an external control signal to the semiconductor switching element with an external control input is changed in response to a power supply request to the different voltage load to only the battery. A control circuit for switching between a state where power can be supplied and a state where power is not supplied to the different voltage load Vehicle power supply apparatus characterized by comprising providing. 2. The different voltage load switch is constituted by a semiconductor switching element with an external control input switchable by an external signal, provided as a semiconductor switching element of the lower half bridge rectifier circuit for the different voltage load. The power supply device for a vehicle according to claim 1, wherein the control circuit switches between a state in which power can be supplied to only the battery and a state in which power can be supplied to only the different voltage load. 3. The power supply device for a vehicle according to claim 1, wherein said semiconductor switching element is constituted by a silicon rectifier. 4. The silicon rectifier according to claim 3, wherein the silicon rectifier comprises a silicon diode or an SCR.
The power supply device for a vehicle according to the above.