JPH04308430A - Two-output type power supply device - Google Patents

Abstract

PURPOSE:To provide a two-output type power supply device which can parallelly drive two or more loads independently of each other and has excellence in vehicle mountability and economical efficiency. CONSTITUTION:A diode bridge 2 feeds the first power supply voltage to the first load 51 and a battery (first accumulating means) 7, and a diode trio 4 feeds the second power supply voltage to the second load 52 and a battery (second accumulating means) 9 through an MOSFET3. A voltage regulator 6 detects the first power supply voltage to control generation of a three-phase AC generator 1, and a controller 8 detects the second power supply voltage to perform switching control of the MOSFET3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-output power supply device capable of supplying power to a plurality of loads in parallel using separate power supply systems.

0002

2. Description of the Related Art Japanese Patent Application Laid-Open No. 1-308133 discloses a dual-output power supply device that uses a plurality of generators to supply different power supply voltages in parallel to a plurality of vehicle loads.

0003

[Problems to be Solved by the Invention] However, the engine room of a car is small and the generator is generally driven by a belt from the engine, so the mounting location is limited.
Only a limited number of vehicles can be equipped with multiple generators. The present inventor previously devised a configuration shown in FIG. 5 as a plan to solve this problem.

This two-output power supply device includes a three-phase alternator 10a, a diode bridge 2a whose input end is connected to the output end of the three-phase alternator 10a, and an anode connected to the three-phase alternator 10a. It has an SCR (silicon controlled rectifier) trio 4a that is individually connected to the output end of the generator 10a, and the generated voltage of the generator 10a is three-phase full-wave rectified by the diode bridge 2a, and is then connected to the first power storage means 7a and the first power storage means 7a. Power is supplied to the load system 51a, and the second power storage means 9a is also supplied by the SCR trio 4a.
And power is supplied to the second load system 52a.

Further, the power supply device includes a voltage regulator 60a and an SCR controller 8a, and the voltage regulator 60a adjusts the field current based on the output voltage of the first power storage means 7a to bring it to the rated voltage value. The SCR controller 8a controls and adjusts the generated voltage of the generator 10a, and the SCR controller 8a controls the second power storage means 9a.
SC to set it as the rated voltage value based on the output voltage of
Switch R.

[0006] According to the above proposal, a small and lightweight dual-output power supply device is possible, for example, one of the load systems is used as an engine electrical load, and the other is used as another vehicle load such as a lighting device or an electronic device. It is possible to operate such that the second load system is not affected by a large voltage drop during large current consumption such as when starting an engine. Furthermore, it is also possible to control the SCR trio to operate the charging of the second load system 52a only when the engine is free.

However, it has been found that the above-mentioned power supply device has the following problems. That is, since each SCR conducts only once during one cycle of the generated voltage frequency, the ripple of the second output voltage V2 supplied to the second power storage means 62a is very large, and therefore the audible electromagnetic noise that is harsh is large. Ta. For reference, the SCR duty ratio is 0.
．． The output current waveform at 5 or less is shown in FIG.

[0008] Furthermore, in a vehicle power supply system, these SCRs and diodes are generally incorporated into a three-phase alternator (alternator), so they tend to reach high temperatures.
There was also concern that the R would be ignited incorrectly due to heat. Furthermore, S
The large forward voltage drop (approximately 1.6 V) of the CR is, for example, so large that it cannot be ignored compared to the conventional rated voltage value for vehicles (12 V), and the resulting element heat generation becomes even more serious when used for vehicles. The present invention has been made in view of the above problems, and an object of the present invention is to provide a two-output power supply device that is small and lightweight, has high rectification efficiency and operational reliability, and has low audible electromagnetic noise.

[0009]

[Means for Solving the Problems] A two-output power supply device of the present invention includes a three-phase alternating current generator, and a three-phase alternating current generator whose input terminal is connected to the output terminal of the three-phase alternating current generator and which charges a first power storage means. A diode bridge for full-wave rectification, a diode trio whose anode and cathode are individually connected to the output terminal of the three-phase alternator and the other is a common output terminal, and a main electrode of the diode bridge. an insulated gate field effect transistor, one of which is connected to the common output terminal and the other of which charges the second storage means; and a voltage regulator that controls the field current of the generator to adjust the generated voltage of the generator. and setting the insulated gate field effect transistor to an appropriate duty based on the output voltage of the second power storage means.
It is characterized by comprising a controller that switches according to the tee ratio.

[0010] The output voltages of the first power storage means and the second power storage means may be the same or different. A battery or a capacitor can be used as the first and second power storage means.

[0011]

[Operation] The diode bridge performs three-phase full-wave rectification of the output voltage of the three-phase alternating current generator to charge the first storage means. The diode trio constitutes a three-phase full-wave rectifier together with one of the high-level diode trio and the low-level diode trio that constitute the diode bridge, and performs three-phase full-wave rectification on the output voltage of the three-phase alternator. 2. Charge the power storage means. An insulated gate field effect transistor (hereinafter referred to as MOSFET) switches the DC voltage output from the diode trio at a predetermined duty ratio to adjust the amount of charge to the second storage means.

Therefore, the first power storage means is maintained at its desired voltage by power generation control of the three-phase alternating current generator, and the second power storage means is maintained at its desired voltage by conduction control of the diode trio by the controller.

[0013]

Effects of the Invention As explained above, the two-output power supply device of the present invention has the advantage of increasing the voltage supplied to the second power storage means (hereinafter referred to as the second power supply device).
a diode trio that performs three-phase full-wave rectification of the output voltage); and a controller that performs switching control of the three-phase full-wave rectified voltage output from the diode trio to determine the amount of charge of the second power storage means, that is, its output voltage. - A is added to a normal three-phase full-wave rectification power supply, so the following effects can be achieved.

[0014] Compared to the conventional dual-output power supply device having two generators, it is possible to significantly reduce the size and weight, and furthermore, the M
Since OSFETs are capable of high-speed switching compared to SCRs, audible electromagnetic noise is small, and there is no false ignition phenomenon at high temperatures, so even if they are incorporated into an alternator, for example, they can produce excellent effects such as high operational reliability. . Furthermore,
The forward voltage drop of a MOSFET can be significantly reduced by using a large element, so even when added to that of a diode trio, it can be lower than the forward voltage drop of an SCR, improving rectification efficiency and reducing element heat generation. becomes possible.

[0015]

[Embodiment] As shown in FIG. 1, this two-output power supply device includes a three-phase alternating current generator 1 driven by a vehicle engine,
Diode bridge 2, MOSFET 3, and diode
The battery 4 includes a battery 7 as a first power storage means, a battery 9 as a second power storage means, a voltage regulator 6, and a controller 8. Note that each of the bridges 2, 3, and 4 is integrated with a three-phase alternator (alternator) 1.

Each output terminal of the stator coil 1a of the three-phase alternating current generator 1 is individually connected to the input terminal of the diode bridge 2, and further individually connected to each anode of the diode trio 4. There is. Each diode of diode bridge 2
The diode is a constant voltage diode, that is, a diode (so-called Zener diode) set in advance to break down at a predetermined reverse bias voltage, and each diode in the diode trio 4 is a Schottky barrier diode. It consists of

Each cathode of the diode trio 4 is a MOS
Battery 9 through FET3 and second power line LH2
The positive end of the battery 9 is connected to the second load 52, and the negative end of the battery 9 is grounded. Controller 8 is battery 7,
Detects the voltage of 9 and converts the output signal voltage (control voltage) to the MOS
Output to FET3 and voltage regulator 6.

The higher output end of the diode bridge 2 is connected to the positive end of the battery 7 and the first load 51 through the first power supply line LH1, and the negative end of the battery 7 is grounded. The voltage regulator 6 adjusts the output voltage V of the controller 6
It consists of a comparator 6b that compares the reference voltage Vref6 with the reference voltage Vref6, and a power transistor 6a that is opened and closed by the comparison output. Connected to line LH1.

The second load 9 consists of a temporary large power load such as a starter motor, a heater for rapid heating, and a defrost heater for defrosting, and the first load 7 consists of other loads. The rating of both batteries 7 and 9 is set to +12V. The basic operation of the above two-output power supply device will be explained below. Three-phase AC voltage is output from an alternator 1 driven by an engine.

The controller 8 detects one of the output voltages of the three-phase alternator and the output voltages of both batteries 7 and 9, and controls the MOSFET 3 accordingly. The output voltage of the generator 1 is adjusted by adjusting the field current 1f. Voltage regulator 6 turns off transistor 6a when the output voltage of controller 8 is higher than a predetermined reference voltage Vref6, and turns on transistor 6a when it is lower than reference voltage Vref6. As a result, the current flowing through the exciting coil 5 is controlled intermittently, and the output voltage of the generator 1 is controlled to a predetermined value.

The details of the controller 8 will be explained with reference to FIG. 81, 82, 83 are comparators, 80 is a frequency-voltage converter, 84 is a deceleration detection circuit, 85, 86, 88, 9
3 is a logic gate, and 91 is a subtraction circuit. First, the MOS
Switching control of FET3 will be explained. A frequency-voltage converter 80 converts the power generation frequency of the generator into a voltage signal, and this voltage signal is compared with a reference voltage Vref1 (corresponding to the idling frequency) in a comparator 81. The comparator 81 outputs an idling signal Vi that becomes high level (1) if the voltage signal is higher than the reference voltage Vref1, that is, if the generator rotational speed is equal to or higher than the idling frequency. On the other hand, the voltage signal is input to the deceleration detection circuit 84. The deceleration detection circuit 84 is composed of, for example, a microcomputer, and checks changes in the voltage signal at regular time intervals, and determines that the vehicle is in a deceleration state and outputs the deceleration signal Vd when the voltage signal decreases by a predetermined level or more within the given time interval. Output. The OR circuit 85 receives both signals Vi,
It outputs the output Vor of Vd.

The comparator 82 compares the output voltage V2 of the second battery 9 with a predetermined reference voltage Vref2, and determines that V2<V
The AND circuit 86 outputs the comparison signal Vc2 which becomes high level in the case of ref2, and the AND circuit 86 outputs the OR output Vor and the comparison signal Vc.
2 and outputs the AND output Vand. On the other hand, the subtraction circuit 91 outputs the output voltage V2 of the second battery 9 and the reference voltage Vre.
f5 and input the difference voltage to a PWM circuit (pulse width modulation circuit) 92. This PWM circuit 92 outputs a pulse signal with a duty ratio proportional to the voltage difference (Vref5-V2). However, when the differential voltage is negative, the duty ratio is set to 0, and the carrier frequency of this PWM circuit 92 is set to 25 KHz, which is sufficiently high above the audible range.

The pulse signal output from the PWM circuit 92 is input to the logic gate 93, and the logic gate 93 is connected to the second load 52.
Heater for turning on the rapid heating heater (not shown) inside.
Receives the conduction signal of the data switch and the above Vand, and
The pulse signal output from the PWM circuit 92 is applied to the gate of the MOSFET 3 only when and is at a high level (1) and the heater switch is cut off.

Therefore, MOSFET 3 controls the second battery voltage V when the engine speed is higher than the idling speed or when the engine has a margin such as in a deceleration state.
2 becomes low, the pulses are intermittent, and if the battery 9 consumes a large amount of power such as a rapid heating heater, it is cut off, causing a large current to concentrate on the second battery 9 and placing a large burden on the alternator. Prevents it from getting stuck.

Next, control of the field current If will be explained. The logic gate 88 outputs a control signal Vo that becomes high level (1) when Vand is low level. This control signal Vo enters the comparator 6b of the voltage regulator 6, and the comparator 6b outputs the power -Turn on transistor 6a to flow field current. Therefore, if the second battery voltage V2 becomes lower than the reference voltage Vref2 when the engine has no margin, such as when the engine speed is lower than the idling speed or the engine is not in a deceleration state, the field current is caused to flow, and the generator 1 starts generating electricity. do.

Further, the comparator 83 compares the output voltage V1 of the first battery 7 with a predetermined reference voltage Vref3, and
Comparison signal Vc becomes high level when 1<Vref3
3 to logic gate 88, thereby outputting logic gate 8
8 becomes high level and drives the voltage regulator 6 to flow a field current and generate electricity. An example of the hardware circuit configuration of the deceleration detection circuit 84 is shown in FIG.

The output voltage of the frequency-voltage converter 80 is delayed for a predetermined time by a delay circuit 94, and the output voltage of the frequency-voltage converter 80 is subtracted from this delayed signal by a subtraction circuit 95, and the subtracted signal is loaded. - The pass filter 96 converts the voltage into DC voltage, and compares the DC voltage with a predetermined reference voltage Vref4. In this way, deceleration can be detected.

The features of this embodiment will be summarized below. (a) One generator can drive two types of loads independently and in parallel, and it is possible to separate the electrical load system of a vehicle into, for example, a steady load system and an unsteady load system and connect them to their respective power sources. can. In this way, negative effects such as voltage drop when using an unsteady large load can be eliminated, and if the engine has room to spare, the battery 9 for driving an unsteady load can be removed.
By charging the battery, the negative effects of the large charging current can be eliminated.

(b) As explained in the second embodiment, high voltage and low voltage can be easily generated from the output voltage of the alternator 1, and the first power supply system (first power supply line LH1
) and the second power supply system (second power supply line LH2) can be connected to loads with different rated voltages. (c) By high-speed switching of MOSFET6, SC
Electromagnetic noise can be reduced compared to R Trio.

(d) In this embodiment, since a shot diode is used for the diode trio 4, its forward voltage drop can be reduced (about 0.4 V). In addition, since a Zener diode is used in the diode bridge 2, even if the shot diode breaks down due to its reverse bias voltage and a breakdown current flows, the Zener diode of the diode bridge 2 breaks down and absorbs the breakdown current. be able to.

Furthermore, in the above embodiment, the second battery 9
Since it adopts a configuration that performs PWM charging, the torque load on the engine is small.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a first embodiment;

[Fig. 2] A circuit diagram showing a control circuit,

[Figure 3] Deceleration detection circuit diagram,

[Fig. 4] Waveform diagram of gate voltage and battery 9 charging current,

[Fig. 5] Circuit diagram of other devices,

FIG. 6 is a signal waveform diagram of the power supply device in FIG. 5;

[Explanation of symbols]

1 is a three-phase alternating current generator, 2 is a diode bridge, 3 is a low-order diode bridge, 4 is a diode trio, 6 is a voltage regulator (first voltage control means), 7 is a battery (first power storage means), 8 is a first load, 7 is a battery (second power storage means), 10 is a second load, and 11 is a control circuit (second voltage control means).

Claims (1)

[Claims] Claim 1: A three-phase alternating current generator, a three-phase full-wave rectifying diode bridge whose input end is connected to the output end of the three-phase alternating current generator and which charges a first power storage means, an anode and a diode bridge. Casso
a diode trio, one of the electrodes being individually connected to the output end of the three-phase alternating current generator and the other being a common output end, and one of the main electrodes being connected to the common output end and the other being a second power storage means. an insulated gate field effect transistor for charging; a voltage regulator for controlling the field current of the generator to adjust the generated voltage of the generator; - a controller for switching a field effect transistor at a predetermined duty ratio.