JP5575424B2 - Synchronous generator - Google Patents

Description

  The present invention relates to a synchronous generator, and more specifically, a three-phase (three-phase three-wire type or three-phase four-wire type) high-voltage AC output and a low-voltage AC output are switched and simultaneously a single-phase three-wire AC output is also provided. The present invention relates to a synchronous generator capable of output.

  In a portable engine generator that generates power by driving a synchronous generator with an engine, three-phase (three-phase three-wire type or three-phase four-wire type) high-voltage AC output (for example, 400V) depending on the place of use and load Those that can be switched to a low-voltage AC output (for example, 200 V) are widely used. In addition, since such a portable engine generator is also used as a power source for electric tools, office machines, etc., the same single-phase three-wire AC output (for example, 100 V and 200 V) as that of a general household is also required. .

  For this reason, both ends of the primary winding of the transformer are connected to both ends of the armature coil of one phase of the three-phase armature coil in the three-phase four-wire synchronous generator, and the secondary winding of the transformer One end of the wire is connected to the neutral point, the output end of the three-phase armature coil and the neutral point are a three-phase four-wire power source, and at the same time the other end of the secondary winding of the transformer and the three-phase A synchronous generator has been proposed in which the output ends of the remaining two armature coils of the armature coil are single-phase three-wire power sources (see, for example, Patent Document 1).

JP 2008-2370099 A

  In the synchronous generator described in Patent Document 1, since both ends of the primary winding of the transformer are connected to both ends of the one-phase armature coil of the three-phase armature coil, the three-phase armature There is no problem if the voltage output from the coil output terminal does not change, but as described above, in the case of a synchronous generator that switches the output of the three-phase alternating current to a high voltage and a low voltage, the transformer must be set. If the voltage is low, the transformer may be damaged when switching to a high voltage, and the output voltage of the single-phase three-wire system will also change, so the equipment connected to this will not work properly. There is a risk of damage.

  Accordingly, an object of the present invention is to provide a synchronous generator that can obtain a single-phase three-wire AC of a predetermined output voltage even if the output voltage of the three-phase AC is switched between a high voltage and a low voltage. Yes.

In order to achieve the above object, a synchronous generator according to the present invention includes a three-phase armature coil Y-connected to a neutral point with a phase difference of 120 degrees, and an inner coil whose inner end is connected to the neutral point. The outer coil is divided into an outer coil connected in series or in parallel with the inner coil, the outer end of the inner coil is connected to the inner end of the outer coil by connecting the outer end of the inner coil and the inner end of the outer coil. When connecting the inner and outer coils in parallel by connecting the inner end of the inner coil and the inner end of the outer coil and connecting the outer end of the inner coil and the outer end of the outer coil. In the synchronous generator that outputs low-voltage three-phase alternating current from the outer end of the outer coil to the outer end of the inner coil of the one-phase armature coil of the three-phase armature coils, the transformer primary Connecting the inner end of the winding and the outer end of the primary winding; The inner ends of the divider of the secondary winding connected to the neutral point, be switched to any output of the high voltage and low voltage of the three-phase alternating current, the three-phase two other armature coils A single-phase three-wire AC is output from the outer end of the inner coil of the phase armature coil and the outer end of the secondary winding of the transformer.

  According to the synchronous generator of the present invention, since the primary winding of the transformer is connected in parallel with the inner coil of the armature coil, the voltage of the three-phase AC generated at the outer end (output end) of the outer coil Since the voltage applied to the primary winding of the transformer does not change even if the voltage is switched to high voltage or low voltage, a single-phase three-wire AC of the specified voltage is output simultaneously with the high-voltage or low-voltage three-phase AC can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of a synchronous generator when a low voltage is output, showing a first embodiment of the present invention. It is a circuit diagram of the synchronous generator at the time of a high voltage output similarly.

  The synchronous generator 11 shown in this embodiment divides the U-phase, V-phase, and W-phase three-phase armature coils 12 into an inner coil 12a and an outer coil 12b connected to the neutral point O. The output voltage can be switched between a high voltage and a low voltage by connecting them in series or in parallel.

  As shown in FIG. 1, the short-circuit state of the short-circuit plate 13a of the voltage switching device 13 connects the outer end U2 of the inner coil 12a in the U phase and the outer end U1 of the outer coil 12b, and the inner coil 12a in the V phase. The outer end V2 and the outer end V1 of the outer coil 12b are connected, the outer end W2 of the inner coil 12a in the W phase is connected to the outer end W1 of the outer coil 12b, and the inner end of each outer coil 12b. When X1, Y1, and Z1 are connected to the neutral point, the inner and outer coils 12a and 12b are connected in parallel.

  As a result, a three-phase alternating current of low voltage (for example, 200 V or 220 V) is applied to the outer ends U1, V1, W1 of each outer coil 12b and the outer ends U2, V2, W2 of each inner coil 12a connected thereto. Is generated, and a three-phase alternating current of low voltage is applied to the output terminals R, S, T of the three-phase output terminal block 15 via the three-phase circuit breaker 14 (three-phase four-wire alternating current when a neutral point O is added). Is output.

  On the other hand, as shown in FIG. 2, the short-circuit state of the short-circuit plate 13a of the voltage switching device 13 is connected to the outer end U2 of the inner coil 12a in the U phase and the inner end X1 of the outer coil 12b. By connecting the outer end V2 of 12a and the inner end Y1 of the outer coil 12b, and connecting the outer end W2 of the inner coil 12a and the inner end Z1 of the outer coil 12b in the W phase, each of the inner and outer coils 12a and 12b becomes Each is connected in series.

  As a result, a high-voltage (for example, 400 V or 440 V) three-phase alternating current is generated between the outer ends U1, V1, and W1 of the outer coils 12b, and the three-phase output terminal block 15 is connected via the three-phase circuit breaker 14. High voltage three-phase alternating current (three-phase four-wire alternating current) is output to the output terminals R, S, and T.

Thus, to be able to switch by switching the short-circuit state of the short-circuiting plate 13 a voltage switching device 13, an output terminal R of the output terminal block 15, S, the voltage output from T to the high voltage and low voltage The outer end of the inner coil 12a of the armature coil 12 of one phase of the U-phase, V-phase, and W-phase armature coils, in this embodiment, in the V-phase The inner end 22a of the primary winding 22 constituting the transformer 21 is connected to the outer end V2 of the inner coil 12a, and the outer end 22b of the primary winding 22 and the secondary winding 23 constituting the transformer 21 are connected. The inner end 23a is connected to the neutral point O, and the inner coil 12a of the other two phases of the three-phase armature coil 12; in the case of this embodiment, outside of the U-phase and W-phase inner coils 12a Ends U2, W2 and the secondary winding 2 of the transformer 21 3, a single-phase three-wire AC (R1, N, T1) is generated at the outer end 23b.

  The generated single-phase three-wire AC (R1, N, T1) is output to the output terminals r, n, t of the output terminal block 25 via the single-phase circuit breaker 24, and between the output terminals r, n, and A single-phase output with a low voltage (for example, 100 V or 110 V) is obtained between the output terminals n and t, and a single-phase output with a high voltage (for example, 200 V or 220 V) is obtained between the output terminals r and t.

  The outer end V2 of the inner coil 12a in the V phase to which the inner end 22a of the primary winding 22 of the transformer 21 is connected, and the outer ends U2, W2 of the other two-phase U phase and W phase inner coils 12a are Since the potential difference from the neutral point O is the same at both the low voltage output and the high voltage output, the output voltage of the three-phase alternating current is switched, for example, switched to 400V or switched to 200V. However, the output voltage of the single-phase three-wire AC (R1, N, T1) can be set to a constant voltage of, for example, 100V and 200V.

  Therefore, it is possible to simultaneously obtain an output to a large motor that operates with 200V or 400V three-phase alternating current and an output to a power tool or office machine that operates with a single-phase alternating current. The output voltage of single-phase AC does not change even when switching according to the load, there is no risk of damage due to high voltage acting on the transformer 21, and power tools and office machines that operate with single-phase AC are stable. And can be operated without any risk of damage to these devices.

  The ratio between the primary voltage in the primary winding 22 of the transformer 21 and the secondary voltage in the secondary winding 23 is generally set to “0.5” with respect to “1” of the primary voltage. However, as described in Patent Document 1, an appropriate magnitude can be obtained by changing the ratio between the primary voltage and the secondary voltage according to the state of the load that supplies the single-phase output. You can select a transformer.

  DESCRIPTION OF SYMBOLS 11 ... Synchronous generator, 12 ... Armature coil, 12a ... Inner coil, 12b ... Outer coil, 13 ... Voltage switching device, 13a ... Short circuit board, 14 ... Three-phase circuit breaker, 15 ... Three-phase output terminal block, DESCRIPTION OF SYMBOLS 21 ... Transformer, 22 ... Primary winding, 22a ... Inner end of primary winding 22, 22b ... Outer end of primary winding 22, 23 ... Secondary winding, 23a ... Inner end of secondary winding 23, 23b ... outer end of secondary winding 23, 24 ... single-phase circuit breaker, 25 ... single-phase output terminal block,

Claims (1)

A three-phase armature coil Y-connected to a neutral point with a phase difference of 120 degrees, an inner coil whose inner end is connected to the neutral point, and an outer electrode connected in series or in parallel to the inner coil When the inner and outer coils are connected in series by connecting the outer end of the inner coil and the inner end of the outer coil, a high-voltage three-phase alternating current is generated from the outer end of the outer coil. Is connected to the inner end of the outer coil and the outer end of the inner coil is connected to the outer end of the outer coil so that the inner and outer coils are connected in parallel. In the synchronous generator that outputs,
The inner end of the primary winding of the transformer is connected to the outer end of the inner coil of one of the three-phase armature coils, and the outer end of the primary winding and the secondary of the transformer Connect the inner end of the winding to the neutral point,
Even if the output is switched to either the high voltage or the low voltage of the three-phase AC, the outer end of the inner coil of the other two-phase armature coil and the secondary winding of the transformer A synchronous generator that outputs single-phase three-wire AC from the outer end of the wire.

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