JP2016025811A - Power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generator that requires no power supply for separate excitation from a permanent magnet and outside and can start power generation more reliably by resuming rotation after rotation stop.SOLUTION: Among an output core 6 wound in an output winding 7 and a field core 8 wound in a main field winding 9 and a sub field winding 10, one is a stator 4 and the other is a rotor 5. Commutation means 11 and 12 are connected to the field windings 9 and 10. In a self-excited power generator for obtaining generated power due to relative rotation of the stator 4 and the rotor 5, magnetization means 2 is provided for magnetizing either the output core 6 or the field core 8 to an extent that can generate a necessary magnetic force for initial excitation in power generation. The magnetization means 2 comprises, for example, a magnetization power supply 14 consisting of a secondary battery or a capacitor and switching means 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a permanent magnet-less generator used for a small wind generator, a generator using running water, or the like.

There are induction generators and synchronous generators as generators that generate electricity by rotation. Induction generators do not require excitation in the rotor windings, but they must be linked to the system and rotated at a high rotational speed to make them compact. Not suitable for generators. Therefore, a synchronous generator is often used in a small wind power generator or the like.
However, since a normal synchronous generator uses a permanent magnet to generate a field, the rare metal that is a component of the permanent magnet is expensive and the entire generator is expensive. Torque increases. For this reason, it is not suitable for a generator that generates power with a slight natural force, such as a small wind power generator. There is a separately-excited synchronous generator that uses an electromagnet instead of a permanent magnet. However, a configuration for supplying power to the electromagnet from the outside is necessary, and the configuration is complicated by an external power source.

  There has been proposed a self-excited synchronous generator that solves these problems and does not require a permanent magnet and external power supply (Patent Document 1). This generator uses the residual magnetism of the iron core to increase the current that flows in the field winding by self-excitation, so that the magnetic flux required for power generation can be supplied with an expensive permanent magnet or an external power source for excitation. Produced without need.

JP 2006-149148 A

  The self-excited generator of the proposed example has excellent advantages as described above, but if the power generation is stopped for a long time or the generator is disassembled, the residual magnetism of the generator core becomes weak. If the residual magnetism of the generator core is weak, the magnetic force necessary for the initial excitation is insufficient, and it is necessary that the power generation is not started or the rotational speed at which the power generation is started is somewhat high. Therefore, in the generator that needs to be stopped like wind power generation or power generation using running water, or that needs to be generated at low speed, the self-excited generator has insufficient certainty of power generation start. It becomes.

  An object of the present invention is to provide a generator that does not require power supply for external excitation from a permanent magnet and from the outside, and that can reliably start power generation by restarting rotation even after the rotation is stopped.

In the generator of the present invention, one of the output iron core around which the output winding is wound and the field iron core around which the main field winding and the sub field winding are wound serves as a stator, and the other serves as a rotor. In a self-excited generator in which a rectifying means is connected to each field winding and the generated electric power is obtained by relative rotation between the stator and the rotor,
Magnetizing means for magnetizing one or both of the output core and the field core is provided to such an extent that a magnetic force required for initial excitation of power generation can be generated.

According to this configuration, since it is a self-excited type that performs excitation using the main field winding, power generation can be performed without the need for a permanent magnet or an external power source that supplies power for external excitation from the outside. Since no permanent magnet is used, no cogging torque is generated, and the rotor can be rotated with a small torque. Although it is self-excited, it has magnetizing means to magnetize any iron core of the generator to the extent that it can generate the magnetic force required for the initial excitation of power generation. Even after or at a low speed, power generation can be reliably started. Since the self-excited generator increases the magnetic flux as it rotates, the magnetic force required for the initial excitation is very small. The magnetizing means is necessary, but it is sufficient that the magnetizing means can be magnetized to such an extent that it can generate a magnetic force necessary for initial excitation of power generation. Compared to a power supply, it can be much smaller.
The term “magnetization” refers to magnetization so that residual magnetism is generated after the end of the magnetization process.

In the present invention, the magnetizing means may be configured to pass a magnetizing current through the output winding or any one of the field windings. By energizing the winding with a current larger than a certain level, the iron core can be magnetized. If the magnetizing means is configured to pass a magnetizing current through the winding, the magnetizing means can be configured simply.
The magnetizing current may be a direct current or a pulsed current. If it is a direct current, the magnetizing means can be configured more simply. When the current is pulsed, it is possible to easily apply a current as strong as necessary for magnetization or to adjust the magnitude of the magnetizing current.

  The magnetizing means configured to pass a magnetizing current through the winding includes a magnetizing power source comprising a secondary battery or a capacitor, the output winding or field winding passing the magnetizing current, and the It may be configured with switching means interposed between the magnetizing power source. With this configuration, the magnetizing means can be a simple configuration.

  In the generator of the present invention, one of the output iron core around which the output winding is wound and the field iron core around which the main field winding and the sub field winding are wound serves as a stator, and the other serves as a rotor. In a self-excited generator in which rectifying means is connected to each field winding and the generated electric power is obtained by relative rotation of the stator and the rotor, it is possible to generate a magnetic force necessary for initial excitation of power generation, Since magnetizing means for magnetizing one or both of the output iron core and the field iron core is provided, power supply for external excitation from the permanent magnet and the outside is unnecessary, and rotation is possible even after rotation stops. Power generation can be reliably started by restarting.

It is explanatory drawing which combined the fracture | rupture front view of the generator main body of the generator concerning 1st Embodiment of this invention, and the circuit diagram of a magnetization means. It is explanatory drawing which expands and shows the electric-machine main body from the generator linearly. It is a circuit diagram which shows the electric circuit structure of the generator main body of the generator. It is an electric circuit diagram of the generator concerning other embodiments of this invention. It is explanatory drawing which shows the fracture | rupture front view and some circuit of the generator main body of the generator concerning further another embodiment of this invention. It is a fracture side view of the generator. It is a graph which shows the rising waveform of the coil voltage and linkage flux by the magnetic field analysis about the generator of FIG. 5, FIG. It is explanatory drawing of the state of the magnetic flux by the magnetic field analysis of the generator. It is explanatory drawing of the other state of the magnetic flux by the same magnetic field analysis.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram combining a broken front view of a generator main body 1 of this generator and an electric circuit diagram of a magnetizing means 2 and an external load 3. FIG. 2 is a schematic diagram in which the generator main body 1 of FIG.

  In FIG. 1, the generator includes a generator main body 1 that includes an annular stator 4 and a rotor 5 that is installed inside the stator 4 so as to be rotatable around the center of the stator 4. The stator 4 includes an output iron core 6 and an output winding 7. This embodiment is an example applied to a two-pole generator, and the output iron core 6 is formed with tooth-shaped magnetic pole portions 6b protruding inward at two locations in the circumferential direction of an annular yoke portion 6a. The output winding 7 is wound around each magnetic pole portion 6b. As shown in FIG. 2, the output windings 7 of the magnetic pole portions 6 b are connected in series so that different magnetic poles appear on the magnetic pole surfaces facing the inner diameter side of the adjacent magnetic pole portions 6 b of the output iron core 6. Both ends of the output winding 7 become terminals 7a and 7b, and an external load 3 is connected to these terminals 7a and 7b as shown in FIG. 1, and current is taken out from the generator.

  The rotor 5 includes a field iron core 8, a main field winding 9 and a sub-field winding 10 wound around the field iron core 8. The field iron core 8 is provided with a plurality of tooth-shaped magnetic pole portions 8b protruding in the circumferential direction on the outer periphery of an iron core body 8a having a center hole. Three magnetic pole portions 8 b are provided for each magnetic pole portion 6 b of the output iron core 6. The main field winding 9 is wound around two adjacent magnetic pole portions 8b and 8b, and each main field winding 9 wound around the two magnetic pole portions 8b and 8b is a set of two. The adjacent magnetic pole groups are connected in series so that different magnetic poles appear on the magnetic pole surfaces. The sub-field winding 10 is shifted in phase by the amount of the main field winding 9 and one magnetic pole portion 8b, and is spread over two adjacent magnetic pole portions 8b and 8b in the same manner as the main field winding 9. It is rolled up. The subfield windings 10 wound around the two magnetic pole portions 8b and 8b are connected in series so that different magnetic poles appear on the magnetic pole surfaces of adjacent magnetic pole pairs that are in pairs. Yes. Terminals at both ends of each series connection body of the main field winding 9 and the sub field winding 10 are shown in FIG. 2 by reference numerals 9a, 9b, 10a, and 10b, respectively.

  As shown in FIG. 3, a rectifying element 11 is connected in parallel to the main field winding 9, and a current in a direction that allows the rectifying element 11 to flow flows through the main field winding 9. The subfield winding 10 is connected in series with the main field winding 9, and a rectifying element 12 is connected in series, and only current in the same direction as the main field winding 9 is supplied to the subfield winding 10. Flowing. The arrows in the figure indicate the direction of current flow.

  This generator is a self-excited generator having such a subfield winding 10, and as shown in FIG. 1, a magnetizing power supply 14 is connected to an output winding 7 via a switching means 13. Are connected in parallel with the external load 3. The magnetizing means 2 is constituted by the magnetizing power source 14 and the switching means 13. The switching means 13 is a semiconductor switching element or a contact switch. The magnetizing power source 14 is a storage means such as a secondary battery or a capacitor. When the external load 3 is a secondary battery, it may be used as a magnetizing power source.

  In order to magnetize, a current of a predetermined magnitude may be passed for a very short time. The degree of magnetization may be such that residual magnetism necessary for initial excitation for the start of power generation is obtained, and is determined by the magnitude of current and the ON time of the switching means 13. The opening / closing operation of the switching means 13 is performed by the opening / closing control means 15. For example, the opening / closing control means 15 monitors the detection signal of the rotation detection means 16 that detects the rotation of the rotor 5. When it is detected that the rotor 5 has started rotating from a stationary state, the switching means 13 is magnetized. Turn it on only for the required setting time. When the rotation stop time of the rotor 5 is short, sufficient residual magnetism remains, so that the opening / closing control means 15 turns on the switching means 13 only when the rotation starts after the rotor 5 stops for a set time or longer. For example, the switching unit 13 may be turned on according to the set conditions. Further, the magnetizing may be performed only when the power generation is not started even when the predetermined rotational speed is reached, or the magnetizing may be performed when the rotation of the generator is stopped every predetermined time. .

  In the embodiment of FIG. 1, the magnetizing power source 14 is connected to the output winding 7. However, as shown in FIG. 4, the magnetizing power source 14 is connected to the field windings 9 and 10 via the switching means 13. May be. Also in this example, the magnetizing power source 14 is a secondary battery or a capacitor. In order to magnetize, a current of a predetermined magnitude may be passed for a very short time. The switching means 13 is controlled to be opened and closed by the opening / closing control means 15 as in the embodiment of FIG.

  The operation of the first embodiment will be described. The operation when the rotor 5 is rotating and generating power will be described. As shown in FIG. 3, since the rectifying element 11 is connected in parallel to the main field winding 9, a current in a direction that allows the rectifying element 11 to flow flows through the main field winding 9. Therefore, a magnetic flux having a direction determined by a current that can be passed through the main field winding 9 is generated. In addition, due to electromagnetic induction, a current flows in a direction that prevents a decrease in magnetic flux in the same direction as a magnetic flux generated by the current, but a current does not flow in a direction that prevents an increase in magnetic flux. Therefore, the decrease of the magnetic flux is prevented, but the increase of the magnetic flux is not prevented. A rectifying element 12 is connected in series to the sub-field winding 10, and only a current in the same direction as the main field winding 9 flows.

  Current flows through the main field winding 9 due to the residual magnetism of the output iron core 6 or the field iron core 8. With this current, the magnetic flux generated by the main field winding 9 changes the magnetic flux linked to the sub field winding 10, and a voltage is generated in the sub field winding 10. With this voltage, the sub-field winding 10 supplies a current through the main field winding 9 and increases the current flowing through the main field winding 9. When no voltage is induced in the subfield winding 10 and no current is supplied, a return current flows through the commutator 11 in the main field winding 9 to maintain the magnetic flux of the main field winding 9. Since the current is supplied to the main field winding 9 and the magnetic flux generated by the main field winding 9 is increased, the magnetic flux linked to the subfield winding 10 is also increased, and a larger current is supplied to the main field winding 9. 9 is supplied. In this manner, the current in the main field winding 9 gradually increases, and a field magnetic flux necessary for power generation is created. Due to the relative motion of the output iron core 6 and the field iron core 8, the flux linkage of the output winding 7 changes to generate a voltage.

  As described above, power is generated while the rotor 5 is rotating. However, if the rotor 5 is stopped for a long time to some extent, there is no residual magnetism in either the output iron core 6 or the field iron core 8, Alternatively, the residual magnetism is insufficient and power generation cannot be started. Therefore, in this embodiment, at the start of the rotation after the rotor 5 is stopped, the switching means 13 of the magnetizing means 2 is turned on to pass a magnetizing current from the magnetizing power supply 14 to the output winding 7, and the output iron core 6. Magnetize. Since the magnetic flux gradually increases as the rotation continues as described above, the degree of magnetization may be such that the residual magnetism necessary for the initial excitation for the start of power generation is obtained. For this reason, in order to magnetize, a current of a predetermined magnitude may be passed for a very short time. By this magnetization, even after the rotor 5 is stopped for a long time, power generation is reliably started by resuming the rotation.

  In the case of the embodiment of FIG. 4, at the start of the rotation after the rotor 5 is stopped, the switching means 13 of the magnetizing means 2 is turned on to pass a magnetizing current from the magnetizing power supply 14 to the main field winding 8. The field iron core 8 is magnetized. Even when the field core 8 is magnetized in this way, power generation is started even after the rotor 5 has been stopped for a long time.

  According to the first embodiment and the generator configured as shown in FIG. 4, the following advantages are obtained. Since it is a self-excited type that performs excitation using the main field winding 9, power generation can be performed without the need for a permanent magnet or an external power source that supplies power for external excitation from the outside. Since no permanent magnet is used, no cogging torque is generated and the rotor 5 can be rotated with a small torque. Although it is self-excited, the magnetizing means 2 for magnetizing one of the iron cores of the generator is provided to such an extent that it can generate the magnetic force required for the initial excitation of power generation. Even after or after low speed rotation, power generation can be started reliably. Although the magnetizing means 2 is necessary, the magnetizing means 2 is sufficient if it can be magnetized to such an extent that it can generate a magnetic force necessary for initial excitation of power generation. Compared to an external power source in, it can be much smaller.

  In the above-described embodiment, the stator 4 side is the output iron core 6 and the rotor 5 side is the field iron core 8. Conversely, the stator 4 side is the field iron cores 9 and 10, and the rotor 5 side is the output iron core. 6 is also acceptable. In the above embodiment, a two-pole generator is used, but a multi-pole generator such as a 4-pole, 8-pole, or 16-pole generator may be used.

FIG. 5 shows an example in which the stator 4 side is a field iron core 8 and the rotor 5 side is an output iron core 6 to form a quadrupole generator. Since the principle is the same as that of the first embodiment, the same reference numerals are assigned to the corresponding parts and the description thereof is omitted. Further, the illustration of the magnetizing means is omitted.
As shown in FIG. 6, the rotor 5 is attached to the shaft 21 and is rotatably supported by a bearing 23 with respect to the frame 22 together with the shaft 21. The stator 4 is fixed to the frame 22. The output winding of the rotor 5 is taken out to the fixed side via the slip ring 24 and the brush 25.

7 to 9 show the results of trial manufacture and magnetic field analysis of the generator having the configuration shown in FIGS.
FIG. 7 shows the rising waveforms of the coil voltage and the linkage flux by magnetic field analysis. From this figure, it can be seen that the linkage flux of the main coil gradually increases. The “main coil” in the same figure is the “main field winding 9” referred to in the embodiment, and the “subcoil” is the “sub field winding 10” referred to in the embodiment. The “rotor coil” is “output winding 7”.
From FIGS. 8 and 9, the change in the magnetic flux density of each part due to the rotation of the rotor 5 can be seen.

DESCRIPTION OF SYMBOLS 1 ... Generator main body 2 ... Magnetization means 3 ... External load 4 ... Stator 5 ... Rotor 6 ... Output iron core 6a ... Yoke part 6b ... Magnetic pole part 7 ... Output winding 8 ... Field iron core 8a ... Iron core main body 8b ... Magnetic pole part DESCRIPTION OF SYMBOLS 9 ... Main field winding 10 ... Sub field winding 11 ... Rectification element 12 ... Rectification element 13 ... Switching means 14 ... Magnetizing power supply 15 ... Opening / closing control means 16 ... Rotation detection means

Claims (5)

  One of the output core wound with the output winding and the field core wound with the main field winding and the sub field winding is the stator, and the other is the rotor. In the self-excited generator that is connected to the stator and obtains generated electric power by relative rotation between the stator and the rotor, the output iron core and the field iron core are produced to such an extent that a magnetic force necessary for initial excitation of electric power generation can be generated. A generator having magnetizing means for magnetizing one or both of the iron cores.   The generator according to claim 1, wherein the magnetizing means is configured to pass a magnetizing current through the output winding or any one of the field windings.   The generator according to claim 2, wherein the magnetizing current is a direct current.   The generator according to claim 2, wherein the magnetizing current is a pulsed current. The generator according to any one of claims 2 to 4, wherein the magnetizing means includes a magnetizing power source comprising a secondary battery or a capacitor, and the output winding for energizing the magnetizing current. Or the generator which consists of a switching means interposed between the field winding and the said magnetizing power supply.

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