JPS5922791Y2 - 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 a desired voltage and frequency, and specifically aims to improve the output waveform. This is the purpose.

First, a conventional device of this type is shown in FIG. 1 and will be explained.

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

103, 104, and 105 are the armature coils 1, respectively.
This is the output terminal of 01.

2 is a first full-wave rectifier composed of a group of thyristors that performs full-wave rectification of the three-phase AC output of the generator 1;
202 is its positive side rectified output end, and 202 is its negative side rectified output end.

3 is a second full-wave rectifier which is connected in parallel to the first full-wave rectifier 2 and the alternating current output of the alternator 1 and is constituted by a group of thyristors; 301 is a negative A side rectified output end 302 is a positive side rectified output end.

Then, the positive side rectification output end 201 of the first rectification device 2
and the negative side rectified output end 301 of the second rectifier 3 are connected to each other and serve as one end a of the AC output, and the negative side rectified output end 202 of the first rectifier 2 and the second
The positive side rectifier output end 302 of the rectifier 3 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 an output at a necessary frequency (for example, 50 or 60 Hz), 9 a first full-wave generator according to the output waveform of the oscillation device 8; Gate output 901 for rectifier 2 and second
This is a gate signal generator that alternately outputs gate outputs 902 for the full-wave rectifier 3.

Although not shown in the figure, each output terminal of the gate output 901 is connected to the gate of each thyristor of the first full-wave rectifier 2, and each output terminal of the gate output 902 is connected to the second full-wave rectifier 2. It is connected to the gate of each thyristor of the wave rectifier 3, respectively.

10 is a power generation intermittent 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 an AC output is generated in the armature coil 101.

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 the necessary frequency (for example, 50 or 60Hz) as described above, and this oscillation output Accordingly, gate conduction signals are generated alternately at the output terminals 901 and 902 of the gate control device 9 in accordance with 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 enters the gate circuit of each thyristor of the first rectifier 2, so conduction occurs, and the three-phase signal generated in the armature coil 101 of the generator 1 is generated. The AC output is full-wave rectified by the first rectifier 2, and the AC output terminal a receives (+) and the output terminal b receives (
=) polarity output is generated.

On the other hand, since there is no signal at the gate output terminal 902 at this time, the second
The rectifying device 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 to the gate output terminal 902, the first rectifier 2 becomes non-conductive, and the second rectifier 3 becomes conductive, and the AC output terminal a is (-), and b is (g).

In this way, the gate conduction signal of the thyristor of each rectifier 2, 3 is adjusted to the gate output terminal 9 according to the oscillation frequency of the oscillation device 8.
By switching to 01 and 902, the rectifiers 2 and 3 can be sequentially switched.

Therefore, an output based on the oscillation frequency of the oscillation device 8 appears at the AC output terminals a, l), that is, a single-phase AC output 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, when the AC load is a single-phase induction motor, etc., the AC output waveform becomes a rectangular wave, the peak voltage becomes low, and at the same time the starting torque increases due to the fact that it contains many high frequency components. It has the disadvantage that it is very difficult to start up in applications where it is small and under mechanical load.

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, 11 is inserted and connected in series between the negative rectification output end 202 of the first full-wave rectifier 2 and the positive rectification output end 302 of the second full-wave rectifier 3. 111 and 112 are the input ends of the first steering wheel handle, and 113 is the output end of the intermediate tap.

Further, 12 is inserted and connected in series between the positive side rectified output end 201 of the first full-wave rectifier 2 and the negative side rectified output end 301 of the second full-wave rectifier 3, similar to the first glue axle 11 described above. 121 and 122 are its input ends, and 123 is its output end, which is an intermediate tap.

FIG. 3 is a waveform diagram for explaining the operation of the invented device, in which a is the output waveform of the output terminal 901 of the gate signal generator 9, b is the output waveform of the output terminal 902, and C is the waveform of the output terminal 902 of the gate signal generator 9.
The AC output waveform when the second glue handle 11.12 is not provided, d is the above-mentioned first. This is an AC output waveform when the second glue handles 11 and 12 are inserted.

The operation of this invented device configured as above will be explained.

Compared to the conventional device shown in FIG. 1, in the invented device shown in FIG.
．． The signal 902 is not such that when one is ON, the other is always OFF, but as shown in Figure 3a, 1), there is a period in which both are conductive.

Therefore, this period is the first. Both thyristors of the second full-wave rectifiers 2 and 3 become conductive.

In this case, if the reactors 11 and 12 are not present and are directly connected to the load 5, the output voltage will be zero when both the full-wave rectifiers 2 and 3 are conducting as shown in Figure C. When the one that was conducting first turns off, it suddenly turns O.
N, resulting in an overshooting square wave.

In this way, during the rest period, it is advantageous to start the single-phase induction motor, but the waveform becomes a rectangular wave that includes overshoot, and the waveform distortion becomes large. Since the armature coil is short-circuited via terminals 2 and 3, the output is lost during this period, resulting in poor efficiency.

However, by inserting and connecting the reactors 11 and 12 between the rectified output ends of each full-wave rectifier as shown in FIG. 2, both the full-wave rectifiers 2 and 3 become conductive as shown in FIG. 3d. During the period when the beam is in contact with the reactor, it gradually decreases without being suddenly short-circuited by appropriately selecting the beam actance, and the energy at this time is stored in the reactor as electromagnetic energy, and then the one which was conducting first is When the full-wave rectifier is turned off, reactor 11.
Due to the glue actance of 12, it does not rise suddenly but gradually rises.

At this time, the electromagnetic energy accumulated in the forward accelerator is released, and the waveform distortion rate becomes extremely small.At the same time, even if there is a period in which both full-wave rectifiers 11 and 12 are conductive as described above, Rather than simply becoming a short-circuit period and reducing efficiency, it is possible to increase the efficiency with which energy can be extracted by repeatedly storing and releasing electromagnetic energy in the reactance.

As described above, this invention is based on the first 1. The first rectifier is connected between the rectifier output ends of the second rectifier.
．． By inserting and connecting the second glue handle and providing a part of the period in which the sirisk groups of the respective rectifiers are conductive, it is possible to improve the waveform distortion rate compared to the conventional method, especially as an AC load. This has the effect that when a single-phase induction motor is used, it can be started easily.

[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 waveform diagram for explaining the operation. In the figure, 1 is a three-phase alternating current generator, 101 is an armature coil, 1
02 is a field coil, and 2 and 3 are thyristor groups. a second full-wave rectifier, 4.10 a switch;
5 is an AC load, 6 is a voltage regulator, 7 is a storage battery, 8 is an oscillation device, 9 is a gate signal generation circuit, 901 is a first gate output terminal, 902 is a second gate output terminal, 11.12 is a 1st. 2nd glue acdle, 111, 112, 121.12
2 is its input terminal, and 113 and 123 are its intermediate taps. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Scope of utility model registration request] (1) A multiphase alternating current generator driven by an engine and having a field coil; a first rectifier configured by a group of thyristors capable of rectifying the alternating current output of the generator; a second rectifier connected in parallel to the first rectifier with opposite polarities and constituted by a group of thyristors; between the negative rectifier output end of the first rectifier and the positive rectifier output end of the second rectifier; a first reactor inserted and connected to the
a second glue axle inserted and connected between the positive rectifier output end of the first rectifier and the negative rectifier output end of the second rectifier; an AC load connected between the intermediate taps of the second glue axle; 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; An AC power supply device comprising: an oscillating device that oscillates; and a gate signal generation circuit capable of supplying a gate signal so that the sirisk groups of the first and second rectifying devices have a part of period in which they are both conductive. (2) The AC power supply device according to claim 1, wherein the AC load is a single-phase induction motor.