JPH1052046A - Portable power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable power supply unit which can attain more reduction in size and manufacturing cost and take out relative high output even with a small-sized generator. SOLUTION: The wave outputted from a target wave output circuit 14 is compared with the detected output from an output voltage detection circuit 5 by a comparator 16. Either of the positive gate control part 15a or negative gate control part 15b of a firing angle control part 15 is selected according to the comparative results, and the continuity angle of the gate selected of respective thyristors SCRk± of a cycro converter CC is controlled according to the timing of a synchronization signal outputted from a synchronization signal forming circuit 18. The voltage applied between respective phases of a three-phase main coil 1 is applied between terminals corresponding to the cycro converter CC, and electric power of a prescribed commercial frequency is generated and outputted according to the firing angle control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable power supply used as a single-phase AC power supply at a commercial frequency or the like.

[0002]

2. Description of the Related Art Conventionally, as a portable power supply used for an emergency power supply, outdoor work, leisure, and the like, for example, a combination of a small engine and a synchronous generator has been widely used.

[0003]

In such a conventional engine generator, since the output frequency depends on the engine speed, for example, in the case of a two-pole machine, 50 Hz (or 6 Hz) is used.
0 Hz) to obtain an AC output of 30 rpm.
It is necessary to maintain the rotation speed at 00 rpm (or 3600 rpm), and the engine speed is relatively low, the operating efficiency is not very good, and the generator has to be enlarged, so that the total weight becomes very large. There was a problem.

On the other hand, in recent years, high-speed AC power is obtained from a generator by operating at a relatively high engine speed, and the AC power is once converted to DC, and then commercialized by an inverter device. A so-called inverter-type generator that converts a frequency into an alternating current and outputs the alternating current has also begun to be spread (for example, Japanese Patent Publication No. 7-67229 and Japanese Unexamined Patent Publication No. Hei 4-35567 by the present applicant).
No. 2).

In the inverter type generator, a DC converter for temporarily converting AC power into DC and an AC converter for converting this DC power into AC of a predetermined frequency again are used. The need for a converter and a circuit for temporarily storing DC power necessitate the use of a large number of expensive power circuit components, thereby further reducing the size and weight of the generator. However, there is a problem that the production is difficult and the production cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and further reduces the size and weight, reduces the manufacturing cost, and can take out a relatively large output even though it is a small generator. It is an object to provide a portable power supply device.

[0007]

In order to achieve the above object, the present invention provides a magnet generator having a three-phase output winding,
A synchronous signal forming circuit for forming a signal synchronized with the output frequency of the generator, and a cycloconverter connected to the three-phase output windings and connected in antiparallel to each other to output a single-phase alternating current 1 A set of variable control bridge circuits;
The variable control bridge circuits connected in anti-parallel to each other,
A bridge drive circuit that, based on a signal from the synchronization signal forming circuit, performs a switching operation alternately every half cycle of an AC current having a target frequency to be supplied to a load and outputs a single-phase AC current having a predetermined frequency; An output voltage adjusting circuit that detects an output voltage of the control variable bridge circuit, compares the detection signal with a set target voltage signal, and controls the bridge drive circuit so that the output voltage is maintained at a substantially constant value. It is characterized by the following.

Preferably, the magnet generator has a magnet rotor and a stator having a large number of magnetic poles, and the synchronization signal is a magnetic pole of the magnetic pole on which the three-phase winding is not wound. It is characterized in that it is taken out from the signal winding wound around.

Further, preferably, the magnet generator is driven by an engine, and a rotor of the magnet generator also serves as a flywheel of the engine.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a portable power supply device according to an embodiment of the present invention.

In FIG. 1, reference numerals 1 and 2 denote output windings wound independently on a stator of an AC generator, respectively.
Reference numeral 1 denotes a three-phase main output winding (hereinafter, referred to as “three-phase main coil”), and reference numeral 2 denotes a three-phase auxiliary output winding (hereinafter, referred to as “three-phase subcoil”).

FIG. 2 is a sectional view of the AC generator.
In the figure, the three-phase main coil 1 is located at 2 in the area A1.
The three-phase sub-coil 2 is composed of a single-pole coil,
It is composed of coils of three poles in two. The rotor R is formed with eight pairs of permanent magnet magnetic poles, and is configured to be rotationally driven by an internal combustion engine (not shown). Note that the rotor R also serves as a flywheel of the engine.

Returning to FIG. 1, three output terminals U, V and W of the three-phase main coil 1 are connected to a cycloconverter (Cycloconve).
rter) connected to the input terminals U, V, W of CC.

FIG. 3 is an electric circuit diagram showing only the cycloconverter CC shown in FIG. 1. As shown in FIG. 3, the cycloconverter CC has 12 thyristors S.
CRk ± (k = 1,..., 6). 1
6 thyristors S out of 2 thyristors SCRk ±
A bridge circuit (hereinafter, referred to as a “positive converter”) BC1 including CRk + mainly outputs a positive current,
A bridge circuit (hereinafter, referred to as a “negative converter”) BC2 including the remaining six thyristors SCRk− mainly outputs a negative current.

As described above, 24 poles (of which 3 poles are
When the three-phase AC output of the three-phase generator of the thyristor SCRk ± is used to generate a synchronizing signal for controlling each gate of the thyristor SCRk ±, the AC of eight cycles per one revolution of the crankshaft is input. Is obtained. Then, the range of the engine speed is set to, for example, 1200 rpm.
m to 4500 rpm (ie, 20 Hz to 75 Hz)
, The frequency of the three-phase AC output is 160 Hz to 600 Hz, which is eight times the engine speed.

Returning to FIG. 1, the three output terminals U, V, W of the three-phase main coil 1 are connected to the positive and negative converters B, respectively.
The output side of the cycloconverter CC is connected to an LC filter 3 for removing harmonic components of the output current, and the output side of the LC filter 3 is connected to the input terminals U, V, W of C1 and BC2. The output is connected to an output voltage detection circuit 5 for detecting a voltage corresponding to the current from which the harmonic component has been removed. The negative input terminal of the output voltage detection circuit 5 is connected to the ground GND of the control system.
The output voltage detection circuit 5 is configured to obtain a single-phase output from both positive and negative input terminals.

The output side of the output voltage detecting circuit 5 is connected to an approximate effective value calculating circuit 8 which calculates and outputs an approximate effective value of the output voltage. Connected to the negative input terminal of A reference voltage output circuit 10 for outputting a reference voltage value of the present power supply device is connected to a positive input terminal of the comparator 9, and an output side of the comparator 9 is
Control function according to the comparison result (for example, proportional function)
And a control function calculation circuit 11 for calculating and outputting.

The output side of the control function calculation circuit 11 is connected to an amplitude control circuit 12 for controlling the amplitude of a sine wave having a commercial frequency of 50 Hz or 60 Hz, which is output from a sine wave oscillator 13. Is also connected to the output side of the sine wave oscillator 13. The amplitude control circuit 12 outputs an amplitude control signal for controlling the amplitude of the sine wave output from the sine wave oscillator 13 according to the control function output from the control function operation circuit 11.

The output side of the amplitude control circuit 12 is connected to a target wave output circuit 14 for outputting a target wave according to the output signal (amplitude control signal), and the output side of the target wave output circuit 14 is connected to a cycloconverter CC. Thyristor SC that constitutes
Conduction angle control unit 15 for controlling the conduction angle of each gate of Rk ±
And the positive input terminal of the comparator 16.

The conduction angle control unit 15 includes a positive converter BC1
Gate control unit 15a for controlling the conduction angle of the gate of each thyristor SCRk + (hereinafter referred to as "positive gate")
And a negative gate control unit 15b that controls a conduction angle of a gate (hereinafter, referred to as a “negative gate”) of each thyristor SCRk− of the negative converter BC2.

Each of the gate controllers 15a and 15b has six comparators (not shown), and each comparator compares the target wave with a synchronization signal (reference sawtooth wave) described later. Is fired at the point in time when they match.

The output side of the output voltage detecting circuit 5 is connected to the negative side input terminal of the comparator 16, and the output side of the comparator 16 is connected to the positive gate control section 15a and the negative gate control section 15a.
b. The comparator 16 compares the voltage output from the output voltage detection circuit 5 with the target wave, and outputs a high (H) level signal or a low (L) level signal according to the comparison result.

When the H level signal is output from the comparator 16, the positive gate control unit 15a is activated, while the negative gate control unit 15b is stopped. When the L level signal is output, conversely, The positive gate control unit 15a is configured to stop, while the negative gate control unit 15b is configured to operate.

The output side of the three-phase sub-coil 2 is connected to a synchronizing signal forming circuit 18.

FIG. 4 is an electric circuit diagram showing an example of the synchronizing signal forming circuit 18. As shown in FIG. 4, the synchronizing signal forming circuit 18 includes six photocouplers PCk (k = 1,...,
6) and six diodes Dk (k = 1,..., 6).

The three-phase currents (U-phase, V-phase and W-phase currents) obtained from the three-phase subcoil 2 are
It is supplied to a bridge-type three-phase full-wave rectifier circuit FR composed of each primary light emitting diode (LED) of Ck and a diode Dk. The three-phase current full-wave rectified by the three-phase full-wave rectifier circuit FR is converted into light by the primary-side LED, and the light output is supplied to each of the secondary-side optical sensors (not shown) of the photocoupler PCk. Is converted to That is, a current corresponding to the three-phase current that has been full-wave rectified by the three-phase full-wave rectifier circuit FR is extracted by the secondary-side optical sensor.
The extracted current is used to generate a synchronization signal (for example, a sawtooth wave) for controlling the conduction angle of the gate of each thyristor SCRk ±, as described later.

FIG. 5 shows the transition of the voltage applied between the U-phase, V-phase and W-phase of FIG.
It is a figure which shows the timing which Ck turns on.

Each line voltage (U-V, U-W, V-W, V
−U, WU, WV) as shown in FIG. 5, the output waveform that has been full-wave rectified by the three-phase full-wave rectifier circuit FR is the output voltage of each line obtained from the main coil. It is 1/6 of the cycle. For example, if the phase angle is between 60 ° and 120 °
, That is, when the U-V voltage is higher than the other line voltages, the photocouplers PC1 and PC5 are turned on in pairs (the other photocouplers are turned off), and thus 3
A voltage corresponding to the U-V voltage is output from the phase full-wave rectifier circuit FR. That is, since a voltage corresponding to the maximum value of each line voltage is output from the three-phase full-wave rectifier circuit FR, the cycle of this voltage is 60 °, and the cycle of the main coil voltage is 1 °. / 6.

FIG. 5 also shows the timing at which each gate of the thyristor SCRk ± is turned on, and FIG. 5 shows that the conduction angle of each gate is set in the range of 120 ° to 0 °. The timing at which it is performed is shown.

When a current is output from cycloconverter CC according to this timing, positive converter B
While each gate of C1 is ignited, the cycloconverter C
When absorbing (supplying) current to C, the negative converter B
Each gate of C2 is fired.

It is not necessary to carry out the ignition continuously over the range shown in the figure, and the same operation can be obtained even if a pulse shown by oblique lines in the figure is applied to the gate.

FIG. 6 shows the thyristors SC of the positive or negative converters BC1 and BC2 with conduction angles α = 120 ° and 60 °.
It is a figure showing a waveform outputted from cycloconverter CC when Rk ± is fired.

In the figure, (a) shows a conduction angle α = 12
The waveform output from the cycloconverter CC when each thyristor SCRk + of the positive converter BC1 is fired at 0 ° is shown, and (b) shows the firing of each thyristor SCRk− of the negative converter BC2 at a conduction angle α = 120 °. Shows the waveform output from the cycloconverter CC when
(C) shows a waveform output from the cycloconverter CC when each thyristor SCRk + of the positive converter BC1 is fired at a conduction angle α = 60 °, and (d) shows a negative converter at a conduction angle α = 60 °. Each thyristor SCR of BC2
The waveform output from the cycloconverter CC when k- is fired is shown.

For example, when each thyristor SCRk + of positive converter BC1 is fired at conduction angle α = 120 °, the waveform output from cyclo converter CC has a full-wave rectified waveform as shown in FIG. Becomes Further, when the conduction angle α = 60 °, each thyristor S of the positive converter BC1
When CRk + is fired, the waveform output from the cycloconverter CC becomes a waveform containing a large amount of harmonic components as shown in FIG.
When a high-cut filter is connected to the output side of C, this harmonic component is removed, and the average voltage is output. As described above, assuming that the input generator is a 24-pole three-phase generator and the engine speed is 3600 rpm, the frequency of the fundamental wave of the harmonic is as follows.

60 Hz (= 3600 rpm) × 8th harmonic ×
3 phase × 2 (full wave) = 2.88 kHz Then, the conduction angle α of the positive converter BC1 is set to 0 ° to 120 °.
By changing the angle in the range of °, the cycloconverter CC can output any positive voltage having an average voltage in the range of 0 V to the full-wave rectified voltage. Also, by changing the conduction angle α of the negative converter BC2 in the same manner, the cyclo converter CC can output any negative voltage whose average voltage is in the range of 0 V to the full-wave rectified voltage.

Next, a method of controlling the conduction angle α will be described.

FIG. 7 is a diagram showing a reference sawtooth wave generated for controlling the conduction angle α. The reference sawtooth wave in FIG. 7 is detected by the secondary-side optical sensor of the photocoupler PCk in FIG. Is generated based on the applied current.

Thyristor SCR1 of positive converter BC1
The reference sawtooth wave corresponding to + has a conduction angle α of 120 ° or more.
In the range of −60 °, a sawtooth wave that becomes 0 V when α = 0 ° corresponds. Then, sawtooth waves having a phase difference of 60 ° are respectively converted into thyristors SCR1 +, 6+, and 2
+, 4+, 3+, and 5+ correspond to each thyristor SCRk +.

On the other hand, thyristor S of negative converter BC2
For the CR1-, a sawtooth wave is generated which is vertically symmetrical with respect to the thyristor SCR1 + and whose phase is shifted by 180 °. Then, similarly to the positive converter BC1, the sawtooth waves having a phase difference of 60 °
-, 6-, 2-, 4-, 3-, 5- correspond to each thyristor SCRk- in this order.

As described above, the reference waveform is constituted by twelve sawtooth waves corresponding to the respective thyristors SCRk ± of the positive and negative converters BC1 and BC2. These sawtooth waves are compared with the target waveform r by twelve systems of comparators (not shown), and the intersection points are the conduction angles of the thyristors SCRk ±.

Then, by taking a sine wave as the target wave and changing the conduction angle α to a sine wave, a sine wave output can be obtained from the cycloconverter CC.

In FIG. 7, the control range of the conduction angle α is expanded from 120 ° to 0 ° described in FIG. 5 to 120 ° to −60 °. Hereinafter, the reason why the control range of the conduction angle α is expanded will be described.

When the conduction angle α is controlled in the range of 120 ° to 0 °, when a capacitive load is connected to the output terminal of the cycloconverter CC and there is a positive potential on the load side,
When the control of lowering the output voltage is performed, each thyristor S
In some cases, a discontinuous point occurs in the relationship between the conduction angle of CRk ± and the output voltage, and the output voltage cannot be stably maintained. That is, in order to lower the output voltage when there is a positive potential on the load side, it is necessary to absorb the positive charge of the load.
Since the conduction angle α is limited to the range of 120 ° to 0 °, the positive converter BC1 cannot absorb the positive charge of the load, and therefore must be absorbed by the negative converter BC2. When the positive charge is absorbed by the negative converter BC2, as described above, the output current from the negative converter BC2 is -full-wave rectified voltage to 0V, so that the positive potential of the load rapidly drops to 0V. As a result, a discontinuous point occurs in the output voltage. At this time, if the conduction angle is increased from 120 ° to −60 °, the negative converter BC
Since the charge of the load can be absorbed up to the positive voltage in Step 2, no discontinuity point occurs in the output voltage, and the stability of the control can be maintained.

However, when the conduction angle is expanded to the negative side in this way, as shown in FIG.
1 and BC2, the intersection of the target wave r and the sawtooth wave becomes two points TO1 and TO2, and selects either the positive or negative converters BC1 and BC2 and the corresponding thyristor SCRK I couldn't decide if I should fire the ± gate. Therefore, in the present embodiment, as described above, one of the positive and negative converters BC1 and BC2 is selected according to the comparison result of the comparator 16.

Returning to FIG. 1, the output side of the synchronizing signal forming circuit 18 has a positive gate control unit 15a and a negative gate control unit 15a.
b. Here, each connection line connecting the synchronization signal forming circuit 18 and each of the gate control units 15a and 15b is composed of six signal lines, and each of the signal lines is connected to the gate control units 15a and 15b, respectively.
, And a sawtooth wave having the timing described with reference to FIG. 7 is supplied to each comparator.

The outputs of the six comparators of the positive gate control unit 15a are connected to the respective thyristors S of the positive converter BC1.
The outputs of the six comparators of the negative gate controller 15b are connected to the negative converter BC2, respectively.
Of each thyristor SCRk-.

In the present embodiment, the synchronizing signal forming circuit 18 is configured to form a synchronizing signal (reference sawtooth wave) according to the three-phase output from the three-phase subcoil 2, but the present invention is not limited to this. Alternatively, a single-phase subcoil may be used instead of the three-phase subcoil 2, and a synchronization signal may be formed in accordance with the single-phase output.

Hereinafter, the operation of the portable power supply device configured as described above will be described.

When the rotor R is driven to rotate by the engine, a voltage is applied between the phases of the three-phase main coil 1 as described above. When each gate of the thyristor SCRk ± is fired by the conduction angle control unit 15, a current is output from the cycloconverter CC in response to the ignition, and the current is filtered by the filter 3 to remove its harmonic components, and the output voltage is reduced. The detection circuit 5 detects the voltage. Each of the detected voltages is output by the approximate effective value calculation circuit 8 after calculating the approximate effective value voltage.

The approximate effective value voltage is calculated by the comparator 9
It is compared with the reference voltage value output from the reference voltage output circuit 10, and a control function (proportional function) is calculated and output by the control function calculation circuit 11 according to the comparison result. More specifically, as the output value from the comparator 9 increases, the control function operation circuit 11
As the difference between the reference voltage output from the circuit and the approximate effective value from the approximate effective value calculation circuit 8 increases, a proportional function that increases the proportional coefficient is calculated and output.

In accordance with the calculated and output control function, the amplitude control circuit 12 generates a control signal for controlling the amplitude of the 50 Hz or 60 Hz sine wave output from the sine wave oscillator 13 and sets the target signal. The wave output circuit 14 outputs a target wave according to the control signal. Here, the output value from the target wave output circuit 14 is provided with upper and lower limits, so that the target wave output circuit 14 cannot output a value larger than the predetermined upper limit or a value smaller than the predetermined lower limit. It is configured. That is, as the output value from the comparator 9 increases and the proportional coefficient of the proportional function output from the control function operation circuit 11 increases, the shape of the target wave output from the target wave output circuit 14 changes from a sine wave. It is transformed into a square wave.

The target wave output from the target wave output circuit 14 is compared with the detection voltage output from the output voltage detection circuit 5 by the comparator 16, and when the voltage of the target wave is higher than the detection voltage, the comparison is performed. When the H level signal is output from the comparator 16 and the positive gate control unit 15a is selected to operate, while the voltage of the target wave is lower than the detection voltage, the L level signal is output from the comparator 16 and , The negative gate controller 15b is selected to operate.

In each comparator of the selected gate control unit out of the positive gate control unit 15a and the negative gate control unit 15b, the target wave from the target wave output circuit 14 and the sawtooth wave from the synchronization signal forming circuit 18 are output. The two are compared, and when they match, a one-shot pulse having a predetermined width is output to the gate of the thyristor SCRk ±, and the conduction angle is controlled.

FIG. 9 is a diagram showing an example of a 50 Hz output waveform generated by the power supply device of the present embodiment.
(A) shows an output waveform at the time of no load, (b) shows an output waveform at the time of rated load, and (c) shows an output waveform at the time of overload.

As shown in FIG. 6, when a temporary overload occurs, for example, the reference voltage output from the reference voltage output circuit 10 and the approximate effective value calculation circuit 8 The output waveform is transformed from a sine wave to a rectangular wave according to the difference from the approximate effective value.

In the present embodiment, the shape of the target wave is changed from a sine wave to a rectangular wave in accordance with the state of the load. However, the present invention is not limited to this, and the output voltage is limited by the maximum amplitude. When the power supply device is configured as described above, the amplitude of the target wave may be increased according to the state of the load.

As described above, in the present embodiment, regardless of the magnitude of the output frequency of the three-phase generator, the output frequency is converted to a predetermined frequency by the cycloconverter CC. Similarly, the output frequency does not depend on the rotation speed of the drive source such as the engine, so that a large output can be obtained at a relatively high rotation speed, and the size and weight of the generator can be reduced. .

Further, since the output of the high-frequency generator can be directly converted to the output of a predetermined low AC frequency such as a single-phase commercial frequency and output, the power circuit components can be greatly reduced. As a result, the manufacturing cost can be significantly reduced.

Further, since a multi-pole magnet generator is used as the generator, the effect of reducing the size and weight of the entire apparatus is great, and the synchronization signal can be easily extracted.

Further, since the rotor R of the generator is used also as the flywheel of the engine, the whole power supply device becomes smaller and more compact.

[0062]

As described above, according to the present invention,
A magnet generator having a three-phase output winding, a synchronizing signal forming circuit for forming a signal synchronized with an output frequency of the generator, and an anti-parallel connected to the three-phase output winding and connected to each other; A pair of variable control bridge circuits that constitute a cycloconverter that outputs a single-phase alternating current, and the variable control bridge circuits connected in antiparallel to each other are supplied to a load based on a signal from the synchronization signal forming circuit. A bridge drive circuit that outputs a single-phase AC current of a predetermined frequency by alternately switching operation every half cycle of the AC current of the target frequency to be detected, and an output voltage of the control variable bridge circuit, and detects this detection signal. An output voltage adjusting circuit that controls the bridge drive circuit so that the output voltage is maintained at a substantially constant value as compared with a set target voltage signal, so that further reduction in size and weight can be achieved. To reduce the manufacturing cost, and further an effect that it becomes possible to take out the relatively large output despite a small generator.

Preferably, the magnet generator has a magnet rotor and a stator having a large number of magnetic poles, and the synchronization signal is a magnetic pole of the magnetic pole on which the three-phase winding is not wound. Since the signal is taken out from the signal winding wound around the device, the effect of reducing the size and weight of the entire device is great, and the taking out of the synchronization signal is simplified.

Further, preferably, the magnet generator is driven by an engine, and the rotor of the magnet generator also serves as a flywheel of the engine, so that the entire power supply device is further reduced in size and size.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a portable power supply device according to an embodiment of the present invention.

FIG. 2 is a sectional view of the alternator of FIG. 1;

FIG. 3 is an electric circuit diagram showing only a cycloconverter portion of FIG. 1;

FIG. 4 is an electric circuit diagram showing an example of a synchronization signal forming circuit 18.

FIG. 5 is a diagram showing a transition of a voltage applied between U phase, V phase and W phase in FIG. 6 or 7, a timing at which a photocoupler is turned on, and a timing at which each gate of a thyristor is fired.

FIG. 6 is a diagram showing waveforms output from the cycloconverter when the thyristors of the positive or negative converter are fired at conduction angles α = 120 ° and 60 °.

FIG. 7 is a diagram showing a reference sawtooth wave generated for controlling a conduction angle.

FIG. 8 is a diagram for explaining a problem that occurs when the conduction angle is set to 120 ° to −60 °.

FIG. 9 illustrates a 50H generated by the portable power supply of FIG. 1;
FIG. 6 is a diagram illustrating an example of an output waveform of z.

[Explanation of symbols]

 Reference Signs List 1 3 phase main coil (3 phase output winding) 5 output voltage detection circuit 14 target wave output circuit (output voltage adjustment circuit) 15 conduction angle control section (bridge drive circuit) 16 comparator BC1 positive converter (variable control bridge) BC2 Negative converter (variable control bridge) CC cyclo converter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location H02P 9/42 H02P 9/42

Claims (3)

[Claims] A magnet generator having a three-phase output winding; a synchronizing signal forming circuit for forming a signal synchronized with an output frequency of the generator; A set of variable control bridge circuits that are connected in anti-parallel and form a cycloconverter that outputs a single-phase alternating current; and the variable control bridge circuits that are connected in anti-parallel to each other,
A bridge drive circuit that, based on a signal from the synchronization signal forming circuit, performs a switching operation alternately every half cycle of an AC current having a target frequency supplied to a load to output a single-phase AC current having a predetermined frequency; An output voltage adjusting circuit that detects an output voltage of the control variable bridge circuit, compares the detection signal with a set target voltage signal, and controls the bridge drive circuit so that the output voltage is maintained at a substantially constant value. A portable power supply device characterized by the above-mentioned. 2. The magnet generator includes a magnet rotor and a stator having a number of magnetic poles, and the synchronization signal is wound around a magnetic pole of the magnetic pole on which the three-phase winding is not wound. The portable power supply device according to claim 1, wherein the portable power supply device is extracted from the signal winding. 3. The portable power source according to claim 1, wherein the magnet generator is driven by an engine, and a rotor of the magnet generator also serves as a flywheel of the engine. apparatus.