JPH09172800A - Self excited single phase induction generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically adjust the leading current of a generator, according to load, by connecting a three-phase capacitor in parallel with three-phase winding, and self-exciting it, and further, connecting a single-phase capacitor in series between the single-phase winding and the load. SOLUTION: When a rotor 3 is driven by external force, electromotive force is induced in the single-phase winding 1 and the three-phase winding 2 of a stator by the residual magnetism of the iron core of the rotor. By this electromotive force, a leading current flows to the three-phase capacitor 4, and the generator gives rise to self exciting phenomena by the rotating magnetomotive force by this current. The single-phase winding 1 and the three-phase winding 2 of the stator are kept at terminal voltage. Here, a single-phase capacitor 5 is connected in series between the single-phase winding 1 and the single-phase load 6. Hereby, the leading current of the generator can be adjusted, according to load change.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a capacitor self-excited single-phase induction generator for connecting a capacitor to a stator winding for self-excitation.

As is well known, when a capacitor is connected to a stator winding of a squirrel-cage induction machine and the rotor is driven by an external force, the induction machine is driven by the residual magnetism of the rotor core and the advance current of the capacitor. It is excited and the stator winding is kept at a certain terminal voltage. At this time, if a single-phase load is connected in parallel with the capacitor, it can be used as a self-excited single-phase induction generator.

However, in the conventional self-excited single-phase induction generator configured as described above, when the capacity of the capacitor is constant, the forward current of the generator cannot be adjusted according to the load change. Therefore, the fluctuation of the output voltage becomes large. Therefore, in order to obtain a constant output voltage, it was necessary to adjust the capacitance of the capacitor according to the load change. In addition, since self-excitation is performed with a single-phase stator winding, the exciting magnetomotive force is small and power generation efficiency is poor. The present invention has been made to solve the above problems, and an object of the present invention is to obtain a self-excited single-phase induction generator with a small output voltage fluctuation and high power generation efficiency.

[Means for Solving the Problems] The stator winding of a squirrel cage induction machine is provided with two sets of windings of three-phase and single-phase, and a three-phase capacitor is connected to the three-phase winding. A single-phase capacitor is connected in series between the phase winding and the load.

In the self-excited single-phase induction generator according to the present invention, since the load current directly flows through the single-phase capacitor, the advance current of the generator is automatically adjusted according to the load change without adjusting the capacity of the capacitor. Changes. Therefore, if the capacitances of the three-phase and single-phase capacitors are properly selected, the exciting current of the generator according to the load can be secured and the fluctuation of the output voltage can be reduced. In addition, since it is self-excited by the three-phase winding, a larger exciting magnetomotive force can be obtained and power generation efficiency is higher than that of the conventional method of self-exciting by the single-phase winding.

1 shows an example of a wiring diagram of a self-excited single-phase induction generator according to the present invention. When the rotor 3 is driven by an external force, the remanent magnetism of the rotor core causes the single-phase winding 1 of the stator.
And an electromotive force is induced in the three-phase winding 2. Due to this electromotive force, a current flows through the three-phase capacitor 4 and a rotating electromotive force caused by this current causes the generator to generate a self-excitation phenomenon. Kept in. Therefore, if a single-phase load 6 is connected to the single-phase winding 1 as shown in FIG. 1, it can be used as a self-excited single-phase induction generator. In the present invention, as shown in FIG. 1, by connecting the single-phase capacitor 5 in series between the single-phase winding 1 and the single-phase load 6, the forward current of the generator can be adjusted according to the load change. To configure. For example, even if the load current i changes as shown in FIG. 2, the output voltage v is kept substantially constant due to the effect of the single-phase capacitor 5, and the sinusoidal output voltage v as shown in FIG. 3 is obtained.

As described above, according to the present invention, the self-excited electric power is efficiently generated by the three-phase capacitor 4 connected to the three-phase winding of the stator while the single-phase capacitor 5 connected in series with the load 6 is used. Due to the effect, the lead current of the generator can be automatically adjusted, and the fluctuation of the output voltage v can be compensated without a controller.
Therefore, compared to the conventional self-excited single-phase induction generator, not only the power generation efficiency is improved, but also a device for voltage compensation is not required, and a high-performance, sturdy, and inexpensive self-excited single-phase induction generator is provided. Obtainable.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a self-excited single-phase induction generator according to the present invention.

[Brief description of reference numerals]

 1 ... Stator single phase winding 2 ... Stator three phase winding 3 ... Basket rotor 4 ... Three phase capacitor 5 ... Single phase capacitor 6 ... Single phase load

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[Procedure amendment]

[Submission date] March 22, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a self-excited single-phase induction generator according to the present invention.

[Fig. 2] Output voltage characteristics of the generator (example)

[Figure 3] Waveform of generator terminal voltage (example)

[Description of symbols] 1 ... Stator single-phase winding 2 ... Stator three-phase winding 3 ... Cage-shaped rotor 4 ... Three-phase capacitor 5 ... Single-phase capacitor 6 ... Single-phase load

Claims (1)

[Claims] The stator of the squirrel-cage induction machine is equipped with two sets of three-phase and single-phase windings, and a three-phase winding is connected in parallel with a three-phase capacitor for self-excitation. A self-excited single-phase induction generator in which a single-phase capacitor is connected in series between the two so that the forward current of the generator can be automatically adjusted according to load changes.