JP3385743B2 - Control device for vehicle generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vehicular generator which stops power supply to a normal voltage load when power is supplied to a high voltage load.

[0002]

2. Description of the Related Art U.S. Pat. No. 4,084,126 has a plurality of switch means and a control circuit, which disconnects an alternator charging a battery and at the same time supplies all of the alternator output to a high capacity load. It discloses driving a high capacity load with an alternator.

Japanese Unexamined Patent Publication No. 64-43037 discloses an alternator output terminal connected to a high-voltage load and a low-voltage load via different relays, and when the high-voltage load is supplied with power, the low-voltage load is used. When the power supply to the low voltage load is restarted when the power supply to the high voltage load is stopped, the relay is disconnected after the excitation current to the exciting coil is cut off to zero. Is disclosed.

[0004]

However, there is a problem that a high surge voltage is generated at the time of load switching in the former publication described above, and the contact life of a relay or the like is shortened. On the other hand, according to the latter publication, load switching is performed in a state in which the exciting current is cut off and the alternator power generation is stopped. Therefore, although the problem of shortening the contact life of the relay due to the surge voltage can be solved, just before switching. After the exciting current was cut off to 0 and the switching was completed, it was necessary to increase the exciting current again to a desired value (for example, a considerably large current value at the time of feeding a high voltage load), and it was necessary to greatly increase or decrease the exciting current. However, the exciting coil has a large reactance, and the exciting current actually applied to the exciting coil is completely set to 0, and thereafter, the exciting coil is actually energized to a level at which high voltage power supply to a high voltage load is possible. A considerable amount of time is required to increase the current, and the switching of the load is delayed by that amount, which causes a problem that, for example, a quick defrosting operation or heating of the catalyst heating heater cannot be performed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a vehicle generator capable of prompt load switching without shortening the life of the changeover switch. I am trying.

[0006]

A first configuration of a control device for a vehicle generator (alternator) according to the present invention is provided between a high voltage load supplied from the vehicle generator, a normal voltage load and a battery. The changeover switch for changing over, the exciting current of the vehicle generator is controlled, and the generated voltage is changed over between the high voltage for the high voltage load and the normal voltage for the high voltage load and the normal voltage for the battery. In advance, the power generation voltage control means for performing power generation at a low voltage equal to or lower than the terminal voltage of the battery for a predetermined period, and switching of the power generation voltage to either the high voltage or the normal voltage is switched based on the command signal. Switching instruction means for instructing the changeover switch to instruct the control means, and the changeover instruction means, after the low-voltage power generation is carried out, Is characterized in that to command said switching to serial changeover switch.

The second configuration of the control device for a vehicle generator (alternator) of the present invention is a changeover switch for switching between a high voltage load fed from the vehicle generator, a normal voltage load and a battery. Generating voltage control means for controlling the exciting current of the vehicle generator to switch the generated voltage between a high voltage for a high voltage load and a normal voltage for a high voltage load and a normal voltage for a battery, and the high voltage or Switching command means for instructing the power generation voltage control means to switch the power generation voltage to either of the normal voltage based on a switching command signal and for instructing switching to the changeover switch, the switching command means, After inputting a switching command from the normal voltage to the high voltage, switching to the high voltage is performed to the power generation voltage control means after switching of the changeover switch. And confirming the power generation at the normal voltage after waiting for a predetermined period after instructing the power generation voltage control means to switch to the normal voltage at the time of inputting the switching command from the high voltage to the normal voltage. Then, the changeover switch is instructed to perform the changeover.

A third structure of the present invention is the above-mentioned first or second.
In the above configuration, the changeover switch is further characterized by comprising a contact relay or FET. In addition,
The changeover switch can be configured by two switching relays or two FETs that operate complementarily to each other instead of the changeover relay having one changeover contact.

A fourth structure of the present invention is characterized in that, in the first or second structure, the battery supplies an exciting current to the generator without passing through the changeover switch.

[0010]

According to the first structure of the present invention,
Before switching between the high voltage load and the normal voltage load, the exciting current is set to a predetermined level to generate power at a predetermined low voltage below the battery voltage for a predetermined period, and the changeover switch is switched during this low voltage generation period. Let it be done.

With this configuration, the electric potential of the battery and the normal voltage load is higher than the generated voltage, so that the full-wave rectifier built in the vehicle generator is reverse-biased, so that the battery and the normal voltage load or the high voltage from the vehicle generator are increased. Since the charging of the voltage load is prohibited, it is possible to prevent the contacts or the breakdown voltage of the relay or FET constituting the changeover switch from being consumed due to the surge voltage during the changeover.

Further, in the present configuration, unlike the conventional case, the excitation current is not set to 0 at the time of switching to stop the power generation, and the power generation is performed at a low voltage equal to or lower than the battery voltage (for example, a power generation voltage equal to the battery voltage). Therefore, there is an excellent effect that the idle time from the input of the switching command to the execution of the switching is short, and the time until the load power feeding is short after the switching is completed.

According to the second configuration of the present invention, when the switching command from the normal voltage to the high voltage is input, the normal voltage power generation is switched to the high voltage power generation after the changeover switch is switched. On the other hand, when a switching command from the high voltage to the normal voltage is input, the changeover switch is switched after switching to the normal voltage power generation. In this way, since the switching can be performed at the normal voltage in either switching operation, it is possible to obtain an effect that the surge voltage generation at the time of switching is small as compared with the switching in the high voltage power generation state.

According to the third structure of the present invention, since the changeover switch is composed of a contact relay or an FET, it is possible to improve wear of the relay contact and disconnection failure due to an arc, and it is not necessary to increase the withstand voltage of the FET. Can play. According to the fourth configuration of the present invention, since the exciting current is supplied to the generator without passing through the changeover switch, the exciting current does not fly back and flow into the load during load switching. It is possible to obtain the effect that the rise of the power generation voltage can be further improved.

[0015]

【Example】

(First Embodiment) A first embodiment of the present invention, which is a control device for a vehicle generator, will be described below with reference to FIG. 1 is a three-phase AC generator for vehicles, 101 is an armature winding thereof, and 102 is a field coil. Reference numeral 2 denotes a three-phase full-wave rectifier, which performs three-phase full-wave rectification on the alternating current of the three-phase AC generator 1 and outputs a high-voltage load 4 and a normal load 5 from an output terminal 201 thereof via a load changeover switch 3 formed of a relay.
And the battery 6 is charged. A control device 8 controls the output voltage of the three-phase AC generator 1.

A controller 9 controls the load changeover switch 3 and the controller 8 to control the power generation state of the three-phase AC generator and the load use state. Reference numeral 7 is an ignition switch, which is OF while the engine (not shown) is not operating.
Therefore, the operation of the control device 8 is stopped. Next, the control device 8 will be described.

Reference numeral 818 denotes a resistor, which is connected in series with the Zener diode 819 and constitutes a constant voltage circuit together with it. When the ignition switch 7 is turned on, a constant voltage is generated at the connection point between the resistor 818 and the Zener diode 819 by the power supply from the battery 6. 8
Reference numeral 01 is a flywheel diode, 802 is a power transistor for controlling the exciting current, and its emitter is grounded. The collector of the transistor 802 is connected to one end of the field coil 102, and the other end of the field coil 102 is connected to the output end 201 of the three-phase full-wave rectifier 2.
It is connected to the. 803 is a transistor, the emitter of which is connected to the base of the transistor 802,
A base current is supplied to the transistor 802 according to the output of the ND circuit 811. Reference numeral 804 denotes a resistor, which is connected to the collector of the transistor 803,
2. Determine the magnitude of the base current supplied to 2. A voltage dividing circuit 806 is connected to the output terminal 201 of the three-phase full-wave rectifier 2, divides the voltage of the output terminal 201 at a predetermined voltage dividing ratio, and applies the voltage to the negative input terminal of the comparator 805.

The resistors 807 and 822 constitute a voltage dividing circuit, which divides the constant voltage from the cathode of the Zener diode 819 and outputs the output voltage of the three-phase AC generator 1 to the + input terminal of the comparator 805. It is applied as a reference voltage Vref for control. The resistor 808 and the transistor 809 are provided in the comparator 805 to switch the output voltage of the three-phase AC generator 1.
Is used to switch the + input voltage.

First, the potential of the control signal input terminal T1 is Hi.
When the level is reached (normal voltage generation and normal voltage load switching are instructed), the Hi level of the control signal input terminal T1 is exceeded.
The level potential is applied to the base of the transistor 809 through the resistor 821, and the transistor 809 is turned on. The resistor 810 is a resistor for maintaining the potential difference between the potential of the control signal input terminal T1 and the constant voltage from the cathode of the Zener diode 819. When the transistor 809 turns on,
According to the resistance value of the resistor 808, the voltage dividing ratio of the reference voltage dividing circuit composed of the resistors 807 and 822 becomes large, and the comparator 80
The reference voltage Vref applied to 5 decreases, and the control level of the output voltage of the three-phase AC generator 1 decreases to a predetermined normal voltage level.

Next, when the control signal input terminal T1 is grounded (when high voltage power generation and high voltage load switching are commanded), the base voltage of the transistor 809 becomes the ground level, the transistor 809 turns off, and the comparator 805 +
The reference voltage Vref applied to the input terminal has a level that is close to the voltage division ratio of the reference voltage dividing circuit, and the control level of the output voltage of the three-phase AC generator 1 increases to a predetermined high voltage level. For example, as the normal voltage of the output voltage of the three-phase AC generator 1, the battery rated voltage level (14.5
V), and its high voltage is set to a level (30 V) considerably higher than the battery rated voltage level.

The output of the comparator 805 is the transistor 80.
3 controls the transistor 802. Next, the configuration of the circuit 80 including the elements 810 to 817 will be described below. This circuit 80 has a circuit configuration for stopping power supply from the three-phase AC generator 1 to the load power supply line 70 for a predetermined time after the level of the switching command voltage at the control signal input terminal T1 changes. The switching command voltage from the input terminal T1 is input to the inverters 814 and 815. 816 is a resistor, 817 is a capacitor,
It constitutes a CR integrator circuit.

Now, when the switching command voltage level from the control signal input terminal T1 changes, the output of the inverter 814 is immediately inverted, but the input voltage of the inverter 813 is thresholded by the delay circuit composed of the resistor 816 and the capacitor 817. The change to the voltage (Vth) is delayed, and the output of the inverter 813 during the delay time T ₀ becomes the same level as the output of the inverter 814.

The outputs of the inverters 814 and 813 are EXN.
It is input to the OR circuit 812, and EXN during the delay time T _0.
The output of the OR circuit 812 becomes Hi level and EXNOR
The output voltage of the circuit 812 turns on the transistor 811. The emitter of the transistor 811 is grounded, and its collector is connected to the + input terminal of the comparator 805. Therefore, when the transistor 811 is turned on, the comparator 8 is divided by the amount of the current shunted through the resistor 810.
The potential of the + input terminal of 05 drops (because of low voltage power generation),
In response to this, the generator 1 generates a low voltage (here, it is sufficiently lower than the normal voltage and refers to a voltage of the battery open voltage) for the delay time T ₀ .

That is, in this embodiment, when the load is switched and the generated voltage is switched accordingly, the generated voltage is once lowered to a low voltage equal to or lower than the battery voltage, whereby the power supply current to the load is stopped and the surge voltage is reduced. Although the switching is performed while reducing the power generation voltage, the power generation voltage itself of the generator 1 is not completely 0, so that the time required to actually decrease and increase the power generation voltage can be shortened.

In the present invention, the method of switching the + input voltage of the comparator 805 has been described, but it goes without saying that the object of the present invention can be achieved by switching the-input voltage. A timing chart of the above operation is shown in FIG. Further, the low-voltage power generation described above may be executed only when switching to one direction, and the changeover switch may be switched during this period.

The procedure of switching the generated voltage by the controller 9 and switching between the high voltage load and the normal load will be described with reference to the flowchart of FIG. First, in step 101, it is determined whether the high voltage load 4 should be used, and if it is used, step 100
Check to see if you were using a high power load at (20
0), if it is not used, the controller 9 outputs Lo from the output terminal A in step 201 in order to increase the generated voltage.
A level voltage is applied to the terminal T1, and in step 202 Ta
After (<T ₀ ) has passed, a Hi level voltage is output from the output terminal B to the switch 3. From these steps 201 and 202, the generated voltage of the AC generator is controlled to a voltage corresponding to the high power load, the switch 3 is connected to the high voltage load 4, and the generated power is supplied to the high voltage load.

Further, since the switch 3 is switched after the lapse of Ta in step 202, the power generation current of the generator is stopped at this time, and a high surge voltage is not generated. If the high voltage load 4 was used in step 200, the current state is maintained. Next, step 1
If it is determined in 01 that the high voltage load 4 is not used, it is checked in step 300 whether power is being supplied to the high voltage load 4,
If there is power supply, step 30 to lower the generated voltage
A Hi level voltage is applied to the terminal T1 from the output terminal A at 1 and a Lo level voltage is outputted from the output terminal B to the switch 3 after Ta (<T ₀ ) has passed at step 302. By these steps 301 and 302, the power generation voltage of the AC generator is controlled to a voltage corresponding to the normal load 5, the switch 3 is connected to the normal load 5, and the power generation voltage is supplied to the normal load 5.
Further, since the switch 3 is switched after Ta in step 302, the power generation current from the generator 1 is stopped at this time, and a high surge voltage is not generated.

If the high voltage load (which may be the high power load) is not used in step 300, the current state is maintained. (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is the same as the first embodiment except that the voltage level of the control signal input terminal T1 changes for a predetermined time.
A circuit 90 including circuit elements or basic circuits 901 to 909 is added so that the generated voltage of the generator is controlled by the phase voltage of the generator.

Reference numeral 901 denotes a voltage dividing circuit, and the divided voltage of the phase voltage Vb of the generator output from the resistors r1 and 2 connected in series charges the capacitor 903 via the diode 902. Therefore, the terminal voltage Vc of the capacitor 903 has a voltage value corresponding to the peak voltage of the phase voltage Vb of the generator. This voltage Vc is input to the-input terminal of the comparator 904, and the reference voltage VL corresponding to the voltage control level of the generator is input to the + input terminal of the comparator 904. Reference voltage V
L is set to a voltage level lower than the battery open voltage level (12.8V).

Now, when the voltage level of the control signal input terminal T1 changes (when switching of the generated voltage is instructed), E
The output of the XOR circuit 909 is at the Lo level A for a predetermined time.
It is input to the ND circuit 907, the output of the comparator 805 is canceled, and the output of the AND circuit 907 becomes Lo level. The output of the EXOR circuit 909 is the inverter 90.
It is inverted in 5 and input to the AND circuit 906, and the output result of the comparator 904 is input to the OR circuit 908.

Therefore, in the transistor 802 which drives the exciting current, the resistor 816 changes when the voltage level of the control signal input terminal T1 changes (when the switching of the generated voltage is instructed).
Controlled by the output result of the voltage VL (low voltage lower than the battery voltage in the present invention) VL indicated by the comparator 904 during the delay time T ₀ determined by the integrator circuit including Will be controlled to a voltage below the battery voltage level.

Therefore, if a three-phase AC generator equipped with the control device 8 of the present invention is used, the generator voltage of the generator 1 is controlled to be lower than the battery voltage level when the generator voltage is switched. The output current is sufficiently low, and it is possible to switch the load while suppressing the generation of a high surge voltage when opening and closing a switch for selectively using a high power load and a normal load.

Further, in the case where the generator generates power by self-excitation,
After the switch is opened / closed, the output of the generator rises quickly, and power can be quickly supplied to the load after the switch is opened / closed. (Embodiment 3) Another embodiment of the present invention will be described with reference to the block circuit diagram of FIG. 5 and the flowchart of FIG.

In the present embodiment, the reference voltage Vref for switching the generated voltage is directly input from the output terminal A of the controller 9 having a D / A converter as an output interface to the comparator 805, and the power generation from the voltage dividing circuit 806 is performed. It is compared with the partial voltage. The output voltage of the comparator 805 is sent to the transistor 803 through the AND circuit 800, the voltage from the ignition switch 7 is input to the other input terminal of the AND circuit 800, and the control device 8 does not operate when the ignition switch 7 is off. It is like this.

The excitation current switching subroutine by the controller 9 will be described below with reference to the flowchart of FIG. First, in step 300, the normal voltage load 5
Is instructed to drive, and if so, the routine proceeds to step 302, where it is checked if the normal voltage load 5 is currently being driven. That is, it is checked whether the changeover switch 3 of FIG. 1 is changed over to the normal voltage load 5 side. If the normal voltage load 5 is being driven, the process returns to the main routine, and if the high voltage load 4 is being driven, the reference voltage Vref is the reference voltage level Vs for normal voltage power generation.
(304), wait for a predetermined time (306), and then
The selector switch 3 is switched to the normal voltage load 4 side (308), and the process returns to the main routine.

On the other hand, in step 300, the normal voltage load 5
If the driving of the high voltage load 4 is not instructed (that is, if the driving of the high voltage load 4 is instructed), the routine proceeds to step 301, where it is checked whether or not the high voltage load 4 is currently being driven. That is, it is checked whether the changeover switch 3 in FIG. 1 is being changed over to the high voltage load 4 side. If the high voltage load 4 is being driven, the process returns to the main routine. If the normal voltage load 5 is being driven, first the changeover switch 3 is switched to the high voltage load 5 side (303), and then the reference voltage Let Vref be the reference voltage level VH for high voltage power generation (3
05), wait for a predetermined time (307), and return to the main routine.

In this way, no matter which side the changeover switch 3 is changed to, the changeover switch 3 is always changed during the normal voltage generation instead of the high voltage generation, so that there is an advantage that the surge is small. (Embodiment 4) Another embodiment of the present invention will be described with reference to the block circuit diagram of FIG.

In this embodiment, the connection ends of the field coil 102 and the cathode of the flywheel diode 801 are connected to the battery 6 via the ignition switch 7 in the configurations of the first to third embodiments. According to this configuration, since the exciting current is directly supplied from the battery 68, the exciting current does not fly back and flow into the load when the load is switched. Therefore, according to the present invention, the generated voltage after the load is switched is changed. The rise is further improved. The same effect can be obtained even if the connecting end is directly connected to the battery 6 without the ignition switch 7.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a control device for a vehicle generator according to a first embodiment of the present invention.

FIG. 2 is a timing chart explaining the operation of the control device for the vehicle generator of FIG.

FIG. 3 is a follow chart for explaining the operation of the controller 9 of FIG.

FIG. 4 is a circuit diagram showing a control device for a vehicle generator according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram showing a control device for a vehicle generator according to a third embodiment of the present invention.

FIG. 6 is a follow chart for explaining the operation of the controller 9 of FIG.

FIG. 7 is a circuit diagram showing a control device for a vehicle generator according to an embodiment of the present invention.

[Explanation of symbols]

1 Three-Phase AC Generator (Vehicle Generator in the Present Invention) 2 Three-Phase Full-Wave Rectifier 3 Changeover Switch 4 High Voltage Load 5 Normal Voltage Load 6 Battery 7 Ignition Switch 8 Control Device (Power Generation Voltage Control Means in the Present Invention , Switching command means), 9 controller (generation voltage control means, switching command means in the present invention).

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Claims (4)

(57) [Claims] 1. A changeover switch for switching between a high voltage load fed from a vehicle generator, a normal voltage load and a battery; and a high voltage load for controlling a magnetizing current of the vehicle generator. Generating voltage control means for switching the generated voltage between a high voltage and a normal voltage load and a normal voltage for a battery, and generating power at a low voltage equal to or lower than the terminal voltage of the battery for a predetermined period before the switching, Switching command means for instructing the power generation voltage control means to switch the power generation voltage to either the high voltage or the normal voltage to the power generation voltage control means based on the switching command signal and for switching the changeover switch. Is for instructing the changeover switch to perform the switching after the low-voltage power generation is performed. Control device. 2. A changeover switch for switching between a high voltage load fed from a vehicle generator, a normal voltage load and a battery; and a high voltage load for controlling a exciting current of the vehicle generator. A generation voltage control means for switching the generation voltage between a high voltage and a normal voltage load and a normal voltage for a battery, and switching of the generation voltage to either the high voltage or the normal voltage based on a command signal Switching command means for instructing the generated voltage control means and for commanding switching to the changeover switch, the changeover command means after switching the changeover switch at the time of inputting a changeover command from the normal voltage to the high voltage. , Commanding the generation voltage control means to switch to the high voltage, and inputting a switch command from the high voltage to the normal voltage After instructing the power generation voltage control means to switch to the normal voltage, after waiting for a predetermined period of time or after confirming power generation at the normal voltage, the switching switch is instructed to switch. A control device for a vehicle generator characterized. 3. The control device for a vehicle generator according to claim 1, wherein the changeover switch comprises a contact relay or a FET. 4. The control device for a vehicle generator according to claim 1, wherein the battery supplies an exciting current to the generator without passing through the changeover switch.