JPH04185240A - Starting charging device for vehicle - Google Patents

Abstract

PURPOSE:To reduce the size of a power transistor by a method wherein a capacitor is charged under high pressure by a high tension winding or by a battery for driving a car load and an inverter inverts the d.c. power of the high-pressure capacitor into an a.c. power at the time of start-up of an engine to supply such power to the high-tension winding for the purpose of starting the engine. CONSTITUTION:When the ignition key is turned on, a control circuit switches transistors 6b of an ac/dc bilateral power transducer 8 in the order which is previously determined, setting up a three-phase pulse voltage. The three-phase pulse voltage is applied to each coil of a high-tension winding 2. As a result, the high tension winding 2 forms a rotating magnetic field and the magnetized rotor starts rotating and then starts up the engine. When the engine speed comes to the specified one, the transistors 6b are all switched off and a capacitor 7 is isolated from the high tension winding 2.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a starting and charging device for a vehicle.

[Conventional technology]

2. Description of the Related Art Conventionally, a vehicle starting/charging device has been proposed which is used as a starting motor/generator for a vehicle.

This device has an AC/DC reversible power converter that connects a three-phase winding wound around an armature and a battery, and this AC/DC reversible power converter configures a three-phase full-wave rectifier to A plurality of diodes charge the battery by rectifying the three-phase AC voltage output from the windings, and a three-phase AC current for starting is transferred from the battery to the three-phase windings by shorting both ends of each diode at a predetermined timing. Multiple power transistors (
In other words, it consists of an inverter).

“Problems to be Solved by the Invention” However, the above-mentioned conventional vehicle starting/charging device
For practical use, it is desired to solve the following problems.

That is, the starting current flowing through the three-phase winding becomes very large, which necessitates the use of large power transistors, and sufficient consideration must be given to their cooling.

Note that if the three-phase winding is rated at a high voltage, it is possible to reduce the current flowing to the power transistor and make it more compact, but it is necessary to add a transformer between the three-phase winding and the above inverter. This results in a complicated circuit configuration and increased power loss.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a starting/charging device for a vehicle that is capable of downsizing a power transistor and reducing power loss during engine starting.

On the other hand, the reciprocating engine that drives this type of device has large torque fluctuations, and there is a desire to reduce this torque fluctuation. In order to reduce this torque fluctuation, it is conceivable to repeat switching between power generation and electric operation of the vehicle starting/charging device according to the torque fluctuation, thereby reducing the torque fluctuation. However, in this application,
Switching between power generation and electric operation causes the problem that fluctuations in the power supply voltage become large, and furthermore, since a large current flows in both power generation and electric operation, there is a disadvantage that the power loss of the transistor is large.

The present specification achieves the above-mentioned first objective, and
A vehicle starting/charging device capable of reducing this engine torque fluctuation is also disclosed in its embodiment.

[Means to solve the problem]

A starting/charging device for a vehicle according to the present invention includes a rotating machine having an armature wound with a low voltage winding having a small number of turns and a high voltage winding having a large number of turns and connected to an engine, and an output from the low voltage winding. a low-voltage rectifier that rectifies alternating current voltage; a vehicle load-driving battery that is charged by the low-voltage rectifier; and a high-voltage condenser for engine starting that is charged by one of the high-voltage windings and the vehicle load-driving battery , an inverter including a plurality of transistors that converts direct current from the high voltage capacitor into alternating current and supplies the alternating current to the high voltage winding.

A capacitor or battery can be used as the high-voltage power storage device.

The low-voltage winding and the high-voltage winding may be of a two-phase winding type as well as a three-phase winding type.

[Action and effect of invention]

In the vehicle starting charger of the present invention, a low voltage winding and a low voltage rectifier as a normal configuration charge a vehicle load driving battery.

On the other hand, the inverter and high-voltage capacitor that characterize the present invention are charged at high voltage by a high-voltage winding or a battery for driving a vehicle load, and the inverter converts the DC power of the high-voltage capacitor into AC power at the time of engine startup and supplies it to the high-voltage winding. supply, thereby starting the engine.

Therefore, according to the present invention, it is possible to downsize the power transistor and reduce resistance power loss when starting the engine.

〔Example〕

An embodiment of the vehicle starting and charging device of the present invention is shown in FIG.

This vehicle starting and charging device has a three-phase rotating machine 100,
This three-phase rotating machine 1OO includes an armature 3 around which a low-voltage winding 1 with a small number of turns and a high-voltage winding 2 with a large number of turns are wound, a rotating field coil 4 that excites the armature 3, and a rotating field coil 4 that excites the armature 3. (not shown).

Furthermore, this vehicle starting charger includes a low voltage rectifier 5 that rectifies the three-phase AC voltage output from the low voltage winding 1, a 12V rated vehicle load driving battery 6 charged by the low voltage rectifier 5, and a high voltage winding. Line 2 and vehicle load drive battery 6
capacitor C for engine starting, which is charged by both
The high-voltage capacitor (as used in the present invention) 7 and the AC/DC reversible power converter (
The present invention includes an inverter 8 and a boost converter 9 that boosts the DC power of the vehicle load driving battery 6 to charge the capacitor 7.

The low voltage rectifier 5 is a three-phase full-wave rectifier, and its output end is connected to the vehicle load driving battery 6 and the high end of the vehicle load, and its low end is grounded.

The AC/DC reversible power converter 8 includes six diodes 8a forming a three-phase full-wave rectifier that performs three-phase full-wave rectification of the three-phase AC voltage output from the high-voltage winding, and the source and drain connected to the anode of each diode 8a. and 6 individually connected to the cathode.
power MOS transistor 6b,
Its low output terminal is grounded, and its high output terminal is capacitor 7.
connected to the high end of the The capacitor 7 is constituted by a large capacity electric double layer capacitor rated at 300 cm, and its lower end is grounded.

The boost converter 9 has one end connected to the vehicle load driving battery 6.
a reactor 9a connected to the high end of the reactor 9a, a diode 9b whose anode is connected to the other end of the reactor 9a and whose cathode is connected to the high end of the capacitor 7, whose collector is connected to the anode of the diode 9b and whose emitter is grounded. It consists of a switching transistor 9C.

The operation of this device will be explained below.

A rotor (not shown) is excited by receiving current supplied from the battery 6 through a regulator (not shown).

Switching transistor 9c of boost converter 9 is switched at high speed by a control circuit (not shown), and as a result, capacitor 7 is charged to 300V.

Now, when the ignition key (not shown) is turned, the AC/DC reversible power converter 8 is turned on by the control circuit (not shown).
A three-phase pulse voltage is generated by switching each transistor 6b in a predetermined order, and this three-phase pulse voltage is applied to each coil of the high voltage winding 2.

As a result, the high voltage winding 2 forms a rotating magnetic field, causing the magnetized rotor to rotate and start the engine.

When the engine is started and reaches a predetermined rotation speed, all transistors 6b are turned off and capacitor 7 is separated from high voltage winding 2.

The rotation of the excited rotor generates an alternating magnetic flux in the armature 3 and generates an electromotive force in the low voltage winding 1 and the high voltage winding 2. As a result, the low-voltage winding 1 charges the low-level rectifier 5 and the battery 6 to drive the vehicle load, and the high-voltage three-phase AC voltage output from the high-voltage winding 2 is applied to each diode 6a of the AC/DC reversible power converter 8. The three-phase aftermath is rectified and charges the capacitor 9.

A modification of the above embodiment will be explained with reference to FIG.

Reciprocating engines have large torque fluctuations due to rotation. When the engine torque is low, a three-phase pulse voltage of a predetermined phase is applied to the high voltage winding 2 by switching control of the transistors 6bx to 6bz to drive the rotor, and conversely, when the engine torque is high, the transistors 6bx to 6bz are activated. The three-phase AC voltage generated by the high voltage winding 2 when turned off is connected to the diode 6a.
Three-phase full-wave rectification is performed at x~6aZ to charge the capacitor 7.

Here, FIG. 2(a) shows the rotational fluctuation of the engine, and FIG. 2(b) shows the torque generated to cancel out this rotational fluctuation. Further, (C) in the same figure shows the change in the motor acting torque in (b) as a pulse width. Each of the transistors 6bx to 6bz is supplied with a PWM (pulse width modulation) signal as shown in FIG. 3(d) to switch between motor action and power generation action.

In this way, vibrations due to engine torque fluctuations can be reduced.

Particularly in this embodiment, since the damping power is temporarily stored by the independent capacitor 7, the load on the battery 6 and the fluctuation in its power supply voltage can be reduced. Furthermore, since the capacitor can be rated at a high voltage of 300V, resistance power loss can be reduced.

Note that the boost converter 9 may be operated when the average value of the charging voltage of the capacitor 7 decreases to, for example, 250 V or less.

As explained above, in the vehicle starting and charging device of this embodiment, the AC/DC reversible power converter and the capacitor have the function of repeating power generation and electric operation in order to reduce engine torque fluctuations. In addition to downsizing the device and reducing power loss, it is possible to reduce engine torque fluctuations with small power loss. That is, since the current in this power generation operation, that is, regenerative braking and electric operation, can be reduced, power loss and heat generation proportional to the square of the current value are reduced, and torque fluctuation reduction efficiency is improved.

Furthermore, since this embodiment includes a boost converter that supplies power from the battery to the capacitor, it is possible to start the engine even if the capacitor used as a power storage device is naturally discharged.

The boost converter starts operating at the moment you turn the ignition key to start the engine, immediately after the engine is stopped, or immediately after a person gets into the vehicle (for example, by detecting that the driver's door is open). (good) or at regular intervals.

[Brief explanation of drawings]

Fig. 1 is an equivalent circuit diagram showing one embodiment of the vehicle starting and charging device of the present invention, and Figs. FIG. 3 is a diagram for explaining a signal waveform of a control voltage applied to a transistor of an AC/DC reversible power converter. 1 is a low voltage winding, 2 is a high voltage winding, 5 is a low voltage rectifier, 6 is a vehicle load driving battery, 7 is a capacitor (high voltage capacitor)
, 8 is an AC/DC reversible power converter (inverter).

Claims (1)

[Scope of Claims] A rotating machine connected to an engine and having an armature wound with a low-voltage winding having a small number of turns and a high-voltage winding having a large number of turns; and a rotating machine that rectifies an AC voltage output from the low-voltage winding. a low-voltage rectifier for driving a vehicle; a vehicle load-driving battery charged by the low-voltage rectifier; a high-voltage condenser for engine starting charged by at least one of the high-voltage winding and the vehicle load-driving battery; A starting and charging device for a vehicle, comprising: an inverter comprising a plurality of transistors that converts direct current into alternating current and supplies the alternating current to the high voltage winding.