JPS5922793Y2 - AC power supply - Google Patents

Description

[Detailed description of the invention] This invention relates to an AC power supply device that controls the AC output of an alternator that is installed in a vehicle or the like and is driven by an engine to any voltage and frequency, and is particularly concerned with improving its waveform. It is something.

First, a conventional device of this kind will be explained with reference to FIG.

In FIG. 1, 1 is a three-phase alternating current generator installed in a vehicle (not shown) and driven by an internal combustion engine (not shown), and has an armature coil 101 and a field coil 102 connected in a star shape. , can generate an alternating voltage of about 100 V.

103, 104, and 105 are output ends of the armature coil 101, respectively.

2 is a first full-wave rectifier composed of a thyristor that performs full-wave rectification of the three-phase AC output of the generator 1, 201 is its (1) rectified output end, and 202 is its (-) rectified output end. .

3 is a second full-wave rectifier connected in parallel to the AC output of the first full-wave rectifier 2 and the alternator 1, and is composed of a thyristor; 301 is a (-) rectifier output; The end 302 is the rectified output end.

Then, the rectifier output end 201 of the first rectifier 2
and the (-) rectifier output end of the second rectifier 3 are connected, and become one end a of the AC output, and the (-) rectifier output end 202 of the first rectifier 2 and the second rectifier 3 (→The rectified output end 302 is connected and serves as the other end of the AC output.

An AC electric load 5 is connected between the AC output terminals a-1) via an AC device switch 4.

6 is a voltage for controlling the AC output voltage to a predetermined value by detecting the voltage between the AC output terminals a and l) and controlling the field current flowing through the field coil 102 of the AC generator 1; A regulating device, 7 a storage battery, 8 an oscillation device that is supplied with power from the storage battery 7 and oscillates at a necessary frequency (for example, 50 or 60 Hz), 9 depending on the output waveform of the oscillation device 8,
This is a gate signal generating device that alternately outputs a gate output 901 for the first full-wave rectifier 2 and a gate output 902 for the second full-wave rectifier 3.

In the figure, gate output 9 is omitted in the figure.
Each output terminal of 01 is connected to the gate of each thyristor of the first full-wave rectifier 2, respectively.

10 is a power generation on/off switch. Next, the operation of the circuit configured as above will be explained.

First, an engine (not shown) is started and the generator 1 is rotated.

In this state, a field magnetomotive force is generated, and the armature coil 101
An alternating current output is generated.

As for this AC output, an AC voltage is simultaneously applied to the first and second rectifiers 2 and 3.

At this time, the voltage of the storage battery 7 is simultaneously applied to the oscillation device 8 and the gate control device 9, so the oscillation device 8 oscillates at a necessary frequency (for example, 50 or 60 Hz), and this oscillation output causes the gate control device 9 to oscillate. output ends 901, 902
Gate conduction signals are generated alternately according to the oscillation frequency of the oscillation device 8.

Therefore, when a gate conduction signal is output to the gate output terminal 901, the conduction signal is input to the thyristor gate circuit of the first rectifier 2, so that conduction occurs to the armature coil 101 of the generator 1.
The three-phase alternating current generated is rectified by the first rectifier 2, and (+) is generated at the alternating current output terminal a and (-) is generated at the alternating current output terminal b.

At this time, since there is no signal at the gate output terminal 902, the second rectifier 3 is in a non-conducting state.

Next, when the gate output from the gate output terminal 901 disappears and a gate conduction signal is output from the gate output terminal 902, the first rectifier 2 becomes non-conductive, and the second rectifier 3 becomes conductive.
AC output terminal a is (-) and b is (issue).

In this way, the rectifiers 2 and 3 can be sequentially switched by switching the gate conduction signal of the sirisk of each rectifier 2 and 3 to the gate output terminals 901 and 902 according to the oscillation frequency of the oscillation device 8.

Therefore, the phase H appears at the AC output terminals a, l) at the oscillation frequency of the oscillation device 8, that is, a single-phase AC is generated.

This single-phase alternating current is affected only by the oscillation frequency of the oscillation device 8, regardless of whether the engine speed changes significantly.

However, in the conventional device described above, for example, when a conductive signal is output to the first gate output terminal 901 and the first full-wave rectifier 2 is conductive, then the first full-wave rectifier 2 is suddenly turned on.
When the conductive signal at the gate output terminal 901 disappears and at the same time a conductive signal is generated at the second gate output terminal 902, the second full-wave rectifier 3 becomes conductive with almost no delay, but the first full-wave rectifier Even if the gate signal is removed, the thyristor of the device remains conductive until the current for one phase becomes less than the holding current of the thyristor during power generation at that moment.

Therefore, during that period, both the first and second full-wave rectifiers 2 and 3 are in a conductive state, and the output of the armature coil 101 is short-circuited, so that no power is supplied to the load 5, resulting in poor output efficiency.

In addition, in order to avoid this short circuit period, If the conduction signals of the second gate output terminals 901 and 902 are not made to be continuous and alternating signals, but a pause period is provided, conversely, within this pause period, the first... A period occurs in which both the second full-wave rectifiers 2 and 3 are cut off, and if the load 5 of the generator 1 is heavy and rotates at high speed, a high voltage surge is generated in the armature coil 101. The armature coil 101 and the full-wave rectifier 2,
It had the disadvantage of causing dielectric breakdown as shown in No. 3.

This invention provides an excellent AC power supply device that eliminates the above-mentioned drawbacks.

An embodiment of this invention shown in FIGS. 2 and 3 will be described below.

In Fig. 2, the anode terminals of 11 and 12 are connected to the AC output terminals a and b, and the cathode terminals are connected to the resistors 1 and 12, respectively.
5 is connected to the reverse current blocking diode, 13.14 is the photocoupler, 131°141 is its light emitting diode,
132 and 142 are phototransistors, and 16 and 17 are collector resistors thereof.

18 is the first two-man power AND element, 19 is the second two-man power A
The ND element 20 is a NOT element.

FIG. 3 is a diagram showing the operating waveforms of this invented device, where A is the output waveform of the oscillation device 8, that is, the manual waveform of the second AND element;
B is the output waveform of the NOT element 20, that is, the input waveform of the first AND element, which is the NOT waveform of the waveform of A.

C is the output waveform between AC output terminals a and l), D is the waveform between c and e, that is, the feedback signal waveform of the photocoupler 13, and E is the waveform between d and e, that is, the feedback of the photocoupler 14. Signal waveform, F is the output waveform of the first gate signal output terminal 901,
G is the output waveform of the second gate signal output terminal 902.

The operation of this invention configured as above will be explained.

First, the output voltage of the oscillator 8 increases, the output potential of the NOT element 20 at point f becomes H1, the output of the first AND element 18 becomes H, and the output voltage of the first gate signal output terminal 901 of the gate signal generator 9 becomes H. When the first full-wave rectifier 2 is in a conductive state, the feedback circuit is operated by the output terminal 20 of the first full-wave rectifier 2.
1 to diode 11. A current flows in the circuit at the (-) output terminal 202 of the first full-wave rectifier 2 via the resistor 15 and the light emitting diode 141 of the photocoupler 14, the light emitting diode 141 emits light, and the phototransistor 142
is conductive.

Therefore, the potential at point d is at L potential.

Next, when the output of the oscillation device 8 changes from L to H, the output potential of the NOT element 20 at the point f or the output potential of the first AND element 18 and the first gate signal output terminal 901 of the gate signal generator 9 becomes L. However, among the thyristor elements of the first full-wave welding device 2, the elements that are already conductive are connected to the armature coil 101.
The conduction is maintained until the polarity of one waveform is reversed and a reverse voltage is applied to the thyristor.

Therefore, during this period, the potential at point d maintains L, and even if the potential at point g mentioned above becomes H, the second AND element 19 and the second gate signal output terminal 902 of the gate signal generator maintain the potential at L. The second full-wave rectifier 3 is not conductive.

In this case, when the output g point potential of the oscillator 8 changes from H to L, a feedback circuit similarly operates in the circuit of the photocoupler 13 and the first AND element 18, and the second full-wave rectifier 3 During conduction, the first full-wave rectifying element 2 does not conduct.

As described above, in this devised device, when one full-wave rectifier is conducting, its waveform is fed back to the circuit that generates the gate signal that makes the other full-wave rectifier conductive. By not emitting conduction signals to the wave rectifier, it is possible to eliminate the short-circuit period that occurs when transitioning from one full-wave rectifier to the other and from the other to one, and at the same time eliminate the idle period. This has the effect of preventing dielectric breakdown without reducing efficiency or generating surge voltage during the idle period.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing a conventional device, FIG. 2 is an electric circuit diagram showing an embodiment of this invention, and FIG. 3 is a diagram showing operating waveforms of each part of this invention. In the figure, 1 is a current generator, 101 is an armature coil, 102
is a field coil, 2 and 3 are three-phase full-wave rectifiers using thyristors, 4.10 is a switch, 5 is an AC load, 6 is a voltage regulator, 7 is a storage battery, 8 is an oscillation device, and 9 is a gate signal generator , 11.12 is a diode, 13.14 is a photocoupler, 131, 141 is a light emitting diode, 132, 1
42 is a phototransistor, 15, 16, 17 are resistors, 18, 19 is an AND element, and 20 is a NOT element. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] an alternator driven by an engine and having a field coil;
a first full-wave rectifier capable of rectifying the alternating current output of the generator, the first full-wave rectifier configured by Cyrisk, the first rectifying device and the alternating current output of the generator being connected in parallel; A second rectifier also constituted by a thyristor, which is connected to the rectifier in opposite polarity to the rectifier; A voltage regulator that controls the output voltage of the generator to a predetermined value by controlling the field current flowing through the field coil, a load that can be driven with an alternating current connected to a second rectifier;
an oscillating device that oscillates a liquid with a predetermined frequency; a gate signal generating device that is controlled by the output of the oscillating device and can alternately supply a conduction signal to the gate circuit of the first rectifying device and the gate circuit of the second rectifying device; In those equipped with
An AC power supply device characterized in that a conduction signal is not generated in a gate circuit of a second rectifier while the second rectifier is in a conductive state.