JP5185637B2 - Synchronous generator - Google Patents

Description

  The present invention relates to a synchronous generator, and more particularly to a synchronous generator capable of simultaneously outputting a three-phase four-wire system and a single-phase three-wire system from a three-phase four-wire AC synchronous generator.

  There are four types of low-voltage synchronous generators for supplying electricity to various loads: three-phase three-wire, three-phase four-wire, single-phase two-wire, and single-phase three-wire. If a three-phase four-wire system and a single-phase three-wire system can be output, electricity can be supplied to most loads. Further, in general, the ordinary tens of kW class generators are predominantly portable engine generators that drive the synchronous generators with the engine.

  Such portable engine power generators are used by moving to various places as temporary power sources for construction and events, and supply electricity to unspecified loads. For example, three-phase 200V is used for power sources such as pumps and motors, and single-phase 100V is used for power sources such as electric tools and office machines. In many cases, a transformer provided on the load side is transformed into a single-phase 100 V. In this case, a transformer must be prepared separately from the portable engine power generator.

For this reason, the armature winding is divided (for example, see Patent Document 1), or another armature winding is combined with the original armature winding (for example, see Patent Document 2). Thus, a synchronous generator having a structure capable of simultaneously outputting a three-phase four-wire system and a single-phase three-wire system has been proposed.
JP 2002-335696 A JP 2004-72985 A

  However, in the above-mentioned patent documents, it is necessary to incorporate an armature winding for single-phase output in the generator in advance when the generator is manufactured, and there is a problem that the size of the generator increases. is there. Furthermore, since the simultaneous use of three-phase and single-phase is not common, it is not economical to incorporate an armature winding for single-phase output that is unlikely to be used. In addition, a method of switching between three and single phases with a switch has been proposed, but in this case, not only a switch is required, but simultaneous use of three and single phases is impossible. Furthermore, since the portable power generation device is operated by an unspecified number of users, it is desired that the portable power generation device has a simple structure and is easy to operate.

  Accordingly, an object of the present invention is to provide a synchronous generator that enables simultaneous use of a three-phase and a single phase by simply performing a simple additional modification to the synchronous generator for three-phase output.

  In order to achieve the above object, a synchronous generator according to the present invention is a three-phase four-wire in which three-phase armature windings (a, b, c) are Y-connected to a neutral point (O) with a phase difference of 120 degrees. In the AC synchronous generator, the primary winding (d) of the transformer (T) is connected to both ends of the one-phase armature winding (c) of the three-phase armature winding (a, b, c). In addition to connecting both ends, one end of the secondary winding (e) of the transformer (T) is connected to the neutral point (O), and the three-phase armature windings (a, b, c) The output end (U, V, W) and the neutral point (O) serve as a three-phase four-wire power source, and at the same time, the other end (N) of the secondary winding (e) of the transformer (T) and the three The output terminals (U, V) of the remaining two armature windings (a, b) of the phase armature windings (a, b, c) are single-phase three-wire power supplies.

  Further, in the synchronous generator according to the present invention, the transformer is formed separately from the generator body, and both ends of the primary winding (d) of the transformer (T) are connected to the three-phase armature winding ( a, b, c) one end of the armature winding (c) of one phase, one end of the secondary winding (e) of the transformer (T) is detachable from the neutral point (O) It is characterized by being connected. The ratio of the primary voltage to the secondary voltage of the transformer (T) is set to 1: 0.5 or less, and the transformer can change the ratio of the primary voltage to the secondary voltage. It is characterized by having.

  According to the synchronous generator of the present invention, three-phase and single-phase simultaneous use is possible only by connecting the primary winding and primary winding of the transformer to the neutral point and one output point of the generator, respectively. . Therefore, since it is not necessary to previously incorporate an armature winding for single-phase output in the generator when the generator is manufactured, the generator itself does not increase in size. Moreover, by providing only the terminals for connecting the transformer in advance, the transformer can be attached and detached as necessary, and it is possible to cope with the place of use. Furthermore, the ratio between the primary voltage and the secondary voltage is basically 1: 0.5. By setting this ratio to, for example, 1: 0.25, the transformer can be reduced in size.

  FIG. 1 is a wiring diagram of an armature winding portion showing an embodiment of a synchronous generator of the present invention, FIG. 2 is a voltage vector diagram when the synchronous generator is driven, and FIG. 3 is a state of a winding of a transformer. 4 is a circuit diagram of the entire synchronous generator, FIG. 5 is an explanatory diagram showing an application example to a portable engine power generator, and FIG. 6 shows the ratio of the primary voltage to the secondary voltage of the transformer 1: FIG. 7 is a diagram showing the theoretical transition of the phase and the single-phase output when the voltage ratio of the transformer is changed.

  The synchronous generator is a three-phase four-wire AC synchronous generator in which three-phase armature windings a, b, and c having the same number of turns are Y-connected to a neutral point O with a phase difference of 120 degrees. Both ends of the primary winding d constituting the transformer T are connected to both ends of the armature winding c of one phase of the three-phase armature windings a, b, c, and the transformer T One end of the secondary winding e to be configured is connected to the neutral point O. By driving the synchronous generator thus connected with an engine or the like, as shown in FIG. 2, a voltage vector is directed toward the output terminals U, V, W of the three-phase armature windings a, b, c. Uv, Vv, and Wv are generated, and the output terminals U, V, and W and the neutral point O serve as a power source that outputs three-phase four-wire power. At the same time, a primary voltage E1 is applied to the primary winding d constituting the transformer T, and a secondary voltage E2 is generated in the secondary winding e of the transformer T. Voltage vectors Uv, Vv, E2 are provided between the end (output end) N and the output ends U, V of the remaining two armature windings a, b of the three-phase armature windings a, b, c. It generates and becomes a power source that outputs single-phase three-wire power. For example, as shown in FIG. 1, when the output terminals U and V are 200 V, the output terminal N of the secondary winding e becomes a neutral point of a single-phase three-wire system and between the output terminals U and N and the output terminal The voltage between N and V is theoretically 100V.

  As shown in FIG. 3, the transformer T has a neutral point O connected between a primary winding d and a secondary winding e arranged in series, and an armature winding c is connected to the tip of the primary winding d. As shown in FIG. 4, the primary winding of the wiring 12 drawn from the neutral point O of the synchronous generator main body 11 is used to incorporate the transformer T into the synchronous generator. Connected between the line d and the secondary winding e, one output W of the synchronous generator is connected to the tip of the primary winding d, and synchronized with the wiring 13 from the tip of the secondary winding e. Three-phase and single-phase simultaneous use is possible only by combining the wirings 14 and 15 connected to the other two outputs U and V from the generator. Further, the MCCB-S is provided in the circuit of the single-phase outputs U, N, V in the same manner as the MCCB (circuit breaker for wiring) -T provided for the three-phase outputs U, V, W. It has been.

  Thus, since the transformer T functions as a single-phase output only by connecting to the wiring drawn out from the synchronous generator main body 11, a three-phase output using a normal three-phase four-wire AC synchronous generator. In the general portable engine power generation apparatus, three-phase and single-phase simultaneous use is possible by additionally remodeling the transformer T.

  For example, as shown in FIG. 5, the portable engine power generator 26 in which the engine 21, the radiator 21 a, the synchronous generator 22, the fuel tank 23, the control device 24 including the AVR, etc. are housed in the casing 25 has a relatively large margin. A portable engine power generator capable of using three phases and a single phase at the same time by installing a transformer T in an upper space in a central portion while being placed on a support stand 27 and connecting necessary wiring. Can do. The only wiring that needs to be added at this time is a wiring branched from the three-phase four-wire output wiring drawn from the synchronous generator 22, and a single-phase three-wire output wiring having a circuit breaker and an output terminal. Therefore, it is not necessary to modify the generator main body or the control device at all, and since no switch for output switching is required, additional modification can be performed very easily. Further, the transformer T can be removed and reused exclusively for three-phase output.

  Further, as shown in FIG. 6, a transformer panel 31 containing the transformer T is installed on the outer surface of the hood of the portable engine power generator 32, or away from the portable engine power generator 32 as shown in FIG. It is also possible to install a transformer panel 31 containing the transformer T on the wall surface of the building 33. In these cases, just add the wiring branched from the three-phase four-wire output wiring drawn from the synchronous generator, and the single-phase three-wire output wiring with the circuit breaker and output terminal. Well, when remodeling a portable engine power generator that does not have enough space to store the transformer T in the internal space or a portable engine power generator that does not have the function of three-phase or single-phase simultaneous use at the site of use. It is valid.

  Further, the ratio m between the primary voltage E1 and the secondary voltage E2 in the transformer T is basically m = 1: 0.5. For example, as shown in FIG. 1, when the three-phase output is 200V, , M = 1: 0.5, and 100V vector lines are completely matched to theoretically set the single-phase output to 100V. However, as shown in FIG. 8, m = 1: 0.25. If the secondary voltage E2 is set low and the vector line of 100V does not match completely, the single-phase output becomes 104V, but there is no problem in practical use, and the voltage is transformed by reducing the secondary voltage E2. The number of turns of the secondary winding e of the transformer T can be reduced, and the transformer T can be reduced in size and cost. FIG. 9 shows the theoretical transition of the phase and the single-phase output when the ratio m is changed. Thus, a transformer having an appropriate size can be selected by changing the ratio m in accordance with the state of the load that supplies the single-phase output.

It is a connection diagram of the armature winding part which shows one example of a synchronous generator of the present invention. It is a voltage vector diagram when a synchronous generator is driven. It is a connection diagram which shows the state of the coil | winding of a transformer. It is a circuit diagram of the whole synchronous generator. It is explanatory drawing which shows the 1st form example applied to the portable engine electric power generating apparatus. It is explanatory drawing which shows the 2nd form example applied to the portable engine electric power generating apparatus. It is explanatory drawing which shows the 3rd form example applied to the portable engine electric power generating apparatus. It is a voltage vector figure when the ratio of the primary voltage of a transformer and a secondary voltage is set to 1: 0.25. It is a figure which shows the theoretical transition of a phase when changing the voltage ratio of a transformer, and a single phase output.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Synchronous generator main body, 21 ... Engine, 22 ... Synchronous generator, 23 ... Fuel tank, 24 ... Control device, 25 ... Casing, 26 ... Portable engine power generator, 27 ... Support stand, 31 ... Transformer board, 32 ... Portable engine power generator, 33 ... Building, a, b, c ... Armature winding, d ... Primary winding, e ... Secondary winding, E1, E2, Uv, Vv, Wv ... Voltage vector, O ... Neutral point, T ... Transformer

Claims (4)

  In a three-phase four-wire AC synchronous generator in which a three-phase armature winding (a, b, c) is Y-connected to a neutral point (O) with a phase difference of 120 degrees, the three-phase armature winding Both ends of the primary winding (d) of the transformer (T) are connected to both ends of the armature winding (c) of one phase of (a, b, c), and the secondary of the transformer (T) One end of the winding (e) is connected to the neutral point (O), and the output end (U, V, W) of the three-phase armature winding (a, b, c) and the neutral point (O ) Is a three-phase four-wire power source, and at the same time, the other end (N) of the secondary winding (e) of the transformer (T) and the rest of the three-phase armature windings (a, b, c) A synchronous generator characterized in that the output terminals (U, V) of the two armature windings (a, b) are single-phase three-wire power sources.   The transformer is formed separately from the generator body, and both ends of the primary winding (d) of the transformer (T) are one phase of the three-phase armature windings (a, b, c). An end of the secondary winding (e) of the transformer (T) is detachably connected to the neutral point (O) at both ends of the armature winding (c) of the transformer. The synchronous generator according to 1.   The synchronous generator according to claim 1 or 2, wherein a ratio of a primary voltage and a secondary voltage of the transformer (T) is set to 1: 0.5 or less.   The synchronous generator according to claim 3, wherein the transformer can change a ratio of a primary voltage and a secondary voltage.

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