WO2004030203A1

WO2004030203A1 - Power generation device

Info

Publication number: WO2004030203A1
Application number: PCT/JP2003/012426
Authority: WO
Inventors: Masaji Haneda
Original assignee: Ntt Data Ex Techno Corporation
Priority date: 2002-09-27
Filing date: 2003-09-29
Publication date: 2004-04-08
Also published as: JP3847740B2; AU2003266680A1; JP2004140991A

Abstract

A rotation device rotates a rotor iron core (5) having a rotor winding (4) together with a commutator (8) with respect to a fixed iron core (2) having a field winding (1) and being excited. The rotation device includes a brush (12) in contact with the commutator (8) and rotated by a synchronous motor (9), a DC power source (14) for applying DC voltage to the brush (12), a windmill (7) for rotating a rotor (6), and an AC power source connected as an exiting power source of the field winding (1) and a drive power source of the synchronous motor (9).

Description

Technical field

The present invention relates to an AC power generator, and more particularly to a power generator having a small size and capable of obtaining an output of a constant frequency regardless of the magnitude of the rotational driving force.

Akira background technology field.

For example, the principle of hydroelectric power and thermal power generation is to transmit the rotational driving force of a water turbine or turbine to an AC generator, generate power based on the rotation of the rotor of the AC generator, and output AC power. In this case, in order to obtain AC power as generator output, the frequency must be constant, the voltage must be adjusted so that it does not exceed the rating, and the current and current according to the power used and the transmission capacity of the transmission line The phase is adjusted, and various kinds of adjustment control are required. For this purpose, for example, various mechanical adjustments such as adjustment control of gas and water flow, that is, adjustment control by a governor, adjustment of the angle of blades of a prime mover, and the like to adjust the rotational force of a turbine and a turbine, which are generator inputs, are performed. Control is needed.

On the other hand, recently, various types of low-power generators such as small hydropower and wind power have been commercialized (wind power has recently emerged with large power), and so-called natural power generation systems This is in line with the trend to completely convert clean energy into electricity. Even with these low-power generators, governors and other equipment and facilities are required, and maintenance and inspection are troublesome.In addition, installation of these power generators requires wind power to obtain rotational driving force. There is also a need to strictly select an installation location where energy can be efficiently obtained by considering the installation environment in advance to be equal to or greater than that for thermal power generation, etc., in order to minimize the effects of dynamic changes such as the above.

In addition, since it is a generator, it is necessary to connect to the grid except for the one for independent operation. In the case of this system interconnection, it is necessary to synchronize the generator output with the commercial power supply frequency.Conventionally, the AC output is converted to DC and the AC is synchronized with the commercial AC power by an inverter to create AC. However, we are taking measures to connect this exchange to the grid.

Patent Document 1

Japanese Patent Application Laid-Open No. 2000-213 15 3 96

'' Even in a large-scale power plant as described above or a low-output power generator, the generator is required to reduce equipment costs, simplify the equipment, and reduce maintenance and inspection by staff. Simplify the power generation system by combining and simplifying as much as possible the devices and facilities that exist, such as detectors, adjustment devices, control devices, and protection devices other than the main unit, such as detectors, adjustment devices, control devices, and protection devices. There is a request to do so. In line with this demand for slimness, this leads to smaller equipment, and depending on the season and season, for example, it can be easily installed and used to generate electricity when the water is abundant or when the wind is strong. This leads to the provision of a power generation device that enables storage.

Also, in wind power generation, etc., the installation location is strictly selected to obtain a steady input as much as possible, but even if there is a large change in the rotational driving force, the effect of the change is reduced and the There is a demand for a power generator that can generate power output.

Furthermore, this is a special case, for example, for an isolated power generator used for ships and mountain huts, etc. In the past, there was a problem that an inverter was separately required and expensive, and the efficiency was reduced due to the AC-DC or DC-AC conversion effect associated with the use of the inverter. . In addition, in the case of grid interconnection, measures to prevent the danger associated with live lines due to inverter operation even in the event of a load failure due to disconnection, etc. Since an interconnecting protection device such as a circuit breaker is required, it must be expensive and complicated in configuration. Furthermore, in wind power generation, there is also a demand that wind energy should be used for power generation as much as possible without separating the rotational driving force from the power generator during strong winds.

The present invention has been made in view of the above-described problems, and has a slim power generation device by minimizing equipment and devices such as an adjustment control device or maintenance and inspection work as much as possible, regardless of the magnitude of the rotational driving force as input. In the case of system interconnection, the configuration of converters such as inverters, measures to prevent islanding and interconnection protection devices required for conventional system interconnection are minimized, and rotational energy is as effective as possible. The purpose is to obtain a power generator that can be used. Disclosure of the invention

In order to achieve the above object, a power generator according to the present invention includes a rotor having a rotor winding and a stator having a stator winding, and the stator is rotated by rotation of the rotor. In a power generating apparatus for obtaining a power generation output from a winding, the rotor winding is excited by a DC power supply through contact switching means that is energized at a predetermined cycle. '

According to the present invention, the exciting current is caused to flow in the rotor winding at a predetermined cycle by the contact switching means, so that an electromotive force is induced in the stator winding due to a change in magnetic flux, and power generation is possible. Become.

The power generator according to the next invention is characterized in that, in the above invention, the stator winding and the wire are connected to an AC power supply and are AC-excited.

According to the present invention, since the stator winding is AC-excited as the field winding, the on / off of the contact switching means synchronized with the AC excitation is defined as the excitation cycle of the rotor winding. Interconnection becomes possible.

In the power generator according to the next invention, in the above invention, the rotor winding is formed by arranging unit windings in a circumferential direction of a rotor core, and all the unit windings are electrically connected windings. It is characterized by being formed.

According to the present invention, the rotor winding is formed by simply winding the unit winding around the rotor core and drumming. A phase or multi-phase winding can be formed and an exciting current can be passed.

In the power generation device according to the next invention, in the above invention, the rotor winding has an electric input / output terminal for each unit winding, and the electric input / output terminal is connected to the contact from the DC power supply. It is characterized in that electricity is supplied via switching means, and rotation is excited at a predetermined period in the circumferential direction of the rotor core on which each unit winding is arranged.

According to the present invention, since the rotor windings are sequentially excited in the circumferential direction for each unit winding via the electric input / output terminal, a rotating magnetic field can be formed.

In the power generation device according to the next invention, in the above invention, the rotor winding has a plurality of unit windings as one set, and each set has an electric input / output terminal. · A power terminal is energized from the DC power supply via the contact switching means, and is rotationally excited at a predetermined cycle in a circumferential direction of a rotor core in which each unit winding is arranged.

According to the present invention, the rotating magnetic field can also be formed by sequentially exciting the plurality of unit windings in the circumferential direction via the electrical input / output terminals.

In the power generation device according to the next invention, in the above invention, the DC power supply includes both a voltage source and a current source.

According to the present invention, the current flowing in the rotor winding can be controlled by switching between the voltage source and the current source.

In the power generation device according to the next invention, in the above invention, the contact switching means has a commutator that rotates integrally with the rotor and a brush that rotates independently by contacting the commutator. And

According to the present invention, a rotating magnetic field having an arbitrary period can be formed in the rotor by performing switching by a unique rotation of the brush, separately from the rotatable commutator.

The power generator according to the next invention is characterized in that, in the above invention, the brush is rotated by a synchronous motor.

According to the present invention, the brush is rotationally driven by the synchronous motor synchronized with the grid. Therefore, power generation synchronized with the grid is possible. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a simplified configuration diagram of a power generator according to a first embodiment of the present invention, and FIG. 2 is a diagram for explaining a change in a direction of a current flowing through a rotor winding 4, FIG. 3 is a diagram for explaining a change in a magnetic field generated in the field winding due to the rotating magnetic field of the rotor. FIG. 4 is a diagram illustrating the rotational speed of the rotor 6 in the power generator according to the first embodiment. FIG. 5 is a diagram showing the relationship between the temperature and the electromotive force (voltage) generated in the field winding 1. FIG. 5 is a simplified configuration diagram of a power generator according to a second embodiment of the present invention. FIG. 7A is a diagram showing the relationship between the rotation speed of the rotor 6 and the electromotive force (voltage) generated in the rotor winding 4 in the power generator according to the second embodiment. FIG. 6 (b) shows the relationship between the rotation speed of the rotor 6 and the electromotive force (voltage) generated in the field winding 1 in the power generator according to the second embodiment. FIG. 7 shows the characteristics of the power generator of the second embodiment from the viewpoint of the DC power supply 14 on the graph of the voltage generated in the rotor winding 4 shown in FIG. 6). FIG. 8 is a diagram showing the configuration of the prototype actually manufactured, and FIG. 9 is a more specific example of the connection of the DC power supply 14 and the rotation mechanism of the brush 12. FIG. 10 is a diagram showing an example of the circuit configuration of the DC power supply 14. FIG. 11 is a diagram showing the waveforms of the field voltage V and the field current I when there is no rotational driving force. Fig. 12 shows the waveforms of the field voltage V and the field current I when there is no rotational driving force (DC power supply not connected, synchronous motor not driven). Fig. 13 shows the shapes of the field voltage V and the field current I when there is a rotational driving force (DC power supply connection, synchronous motor drive). It is a diagram. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of a power generation device according to the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment] FIG. 1 is a simplified configuration diagram of a power generator according to a first embodiment of the present invention. This power generator can function both as a single-operation power generator and as a grid-connected power generator, but this embodiment shows a configuration in the case of functioning as a single-operation power generator. In the configuration diagram shown in the figure, the configuration of the power generation device is slightly modified or shown as a schematic configuration in order to easily explain the configuration. For example, in an actual power generator, the rotor 6 is inserted into the pole piece 22, but in the figure, the rotor 6 is overlapped with the pole piece 22 in order to clarify the schematic structure of the rotor 6. It is displayed so that it does not become.

In FIG. 1, a field winding (stator winding) 1 is wound on a stator 3 having a stator core 2, and a rotor winding 4 is wound on a rotor core. A rotor 6 having 5 is rotatably arranged using a windmill 7 as a driving motor as a drive source. A commutator 8 having a plurality of commutator pieces 81 connected to the rotor winding 4 is rotatably attached to the rotor 6.

The ends of the yoke 21 of the stator core 2 on which the field windings 1 are wound constitute two field poles each having a pole piece 22. In this case, the field poles can have not only a two-pole configuration but also a multiple of two. Further, the field winding 1 can be connected to a three-phase AC power supply, but can also be configured to have three poles or a multiple of three as the field poles. It should be noted that the shape of the stator core 2 in FIG. 1 is not an actual shape, but is shown as forming the end of the yoke 21 of the stator core 2 for convenience of explanation. Further, the pole piece (field pole) 22 has a shape adapted to the rotor 6, and the yoke 21 has a simplified diagram as a structure in which the pole pieces 22 are connected and the field winding 1 is wound. I have.

The rotor 6 is composed of a plurality of type winding coils each having a coil side 41 inserted into a slot formed linearly in the axial direction and arranged equally in the circumferential direction of the outer periphery thereof. have. The winding ends (electrical input / output terminals) of each type coil are individually connected to the rectifier pieces 81, respectively. As described above, the structures of the stator 3 and the rotor 6 are so-called AC commutator machines. Thus, the brush 12 is synchronously rotated in the circumferential direction of the rectifier 8 by the drive of the synchronous motor 9 while being in contact with the commutator 8. In other words, Fig. 1 has the structure of a so-called AC commutator machine as a generator, but the brushes 12 keep the positional relationship between the brushes forming a pair, and the commutator pieces 8 The commutator 8 is synchronously rotated in the circumferential direction (hereinafter, simply referred to as the circumferential direction) while maintaining the desired contact resistance value between 1 and 1. The synchronous rotation state of the brushes 12 is always maintained regardless of whether the rotor 6 and the commutator 8 are stopped due to no rotational driving force from the windmill or are being rotated by the rotational driving force.

In FIG. 1, slip rings 10 and 11 attached to a rotating shaft 17 of the synchronous motor 9 are used to connect a DC power supply 14 placed in an installed state to a brush 12 which is a rotating part. Although it is necessary, when the DC power supply 14 is mounted on the rotating shaft and is integrally rotated, the slip rings 10 and 11 and the brushes contacting the slip rings 10 and 11 are not required.

FIG. 2 is a diagram for explaining the change in the direction of the current flowing through the rotor winding 4. The rotor winding 4 composed of 12 unit windings (type winding coil) and the rotor winding 4 The figure shows a state in which an AC commutator machine having a commutator 8 to which is connected is flatly developed. Here, since the structure of the rotor winding provided in the general AC commutator machine is basically the same as the structure of the rotor winding 4 provided in the power generator of the present invention, The above-described change in the current direction will be described by taking the AC commutator machine as an example. In FIG. 2, the brush 12 contacts the commutator piece 81 of the commutator 8 to form a closed circuit between the DC power supply 14 and the rotor winding 4. At this time, the current from the DC power supply 14 is divided into two directions, right and left, in the rotor winding 4 from the two positions on the left to the two positions on the right in the figure. Become. Then, when the brush 1 2 contacts the next brush movement position by the rotation of the brush 1 2, for example, the position of the commutator piece 8 1, the position of the brush on the left side is shifted from the position of the left side to the position of the right side. Then, the flow in the rotor winding 4 is divided into two directions, right and left.

Thus, by rotating the brushes 12 in synchronization with the commercial power frequency, As a result, the contact position of the brush 12 shifts in order, and the current from the DC power supply 14 flowing in the rotor winding 4 is sequentially shifted to the next unit winding. This means that a rotating magnetic field that rotates in synchronism with the frequency of the commercial power supply is generated by the change in the electromagnet M force current indicated by the dashed line in the figure caused by the current flowing in the DC winding 14 and the rotor winding 4. Will be done. That is, due to the forward movement of the brushes 12 'on the commutator pieces 81, conduction switching between the brushes 12 and the commutator pieces 81 (constituting contact switching means) occurs, and the DC power supply 14 This current causes the rotor 6 to generate a rotating magnetic field due to the transition current in the rotor winding 4.

FIG. 3 is a diagram for explaining a change in a magnetic field generated in a field winding by a rotating magnetic field of a rotor. In the rotor 6, a current flowing from the DC power supply 14 through the slip ring 11 (not shown) and the brush 12a (shown by a black circle in the figure) flows through the rotor winding and the wire 4, and the brush 1 2b (Indicated by white circles in the figure), return to the DC power supply 14 through the slip ring 10 (not shown). The current flowing through the rotor winding 4 generates a rotating magnetic field in the rotor 6 as shown in FIG. This rotating magnetic field causes a change in the magnetic field in the pole pieces 22, causing an induced electromotive force in the field winding 1.

In FIG. 3, the change in the intensity of the magnetic field generated in the field winding 1 is indicated by the size of the characters N and S in the figure. This change in the magnetic field is caused by a change in the amount of magnetic flux linked to the field winding. In the condition (1), the pole piece on the left side of the figure has an S pole of the opposite polarity to the N pole of the rotating magnetic field, and the pole piece on the right side of the figure has an N pole of the opposite polarity to the S pole of the rotating magnetic field. On the other hand, in the condition (5), the pole piece on the left side of the figure has an N pole opposite in polarity to the S pole of the rotating magnetic field, and the pole piece on the right side in the same figure has a polarity opposite to the N pole of the rotating magnetic field. An S pole occurs. Thus, the strength of the magnetic field generated in the field winding by the rotation of the rotating magnetic field changes as shown in (1) to (5). On the other hand, the electromotive force generated in the field winding is proportional to the change in the amount of magnetic flux, that is, the change in the magnetic field. Therefore, as shown in the figure, it becomes maximum in the state of (3), and (1) and (5) In the state of, it is almost 0. In the description so far, the wind turbine 7 has been stopped and the rotor 6 has been treated as physically non-rotating without any special notice. Therefore, Next, the case where the rotor 6 is physically rotated by the rotation of the windmill 7 will be described.

First, consider the period of the rotating magnetic field. The change in the rotating magnetic field is caused by rotating the brush 12 as described above. That is, as shown in FIG. 3, the change in the rotating magnetic field is such that a half-period rotating magnetic field is formed between (1) to (5), and this period is caused by the electromotive force induced in the field winding 1. Is the same as the period. That is, the period of the rotating magnetic field is the same as the rotation period of the brushes 12 and does not depend on the rotation speed of the rotor 6. From this, in FIG. 1, the frequency of the AC output output from the field winding 1 can be controlled by the synchronous motor 9 without depending on the rotation speed of the rotor 6. For example, when the synchronous motor 9 rotates in synchronization with the frequency of the commercial power supply, an AC output having the same frequency as the commercial power supply can be obtained.

Next, the magnitude of the electromotive force generated in the field winding 1 will be considered. The fact that the magnitude of the electromotive force generated in the field winding 1 is proportional to the amount of change in the magnetic flux linking the field winding 1 is as described above. That is, the magnitude of the electromotive force generated in the field winding 1 is proportional to the amount of magnetic flux interlinking the field winding 1 per unit time. On the other hand, as the windmill 7 physically rotates and the rotation speed increases, the number of unit windings of the rotor winding 4 that crosses the field winding 1 increases. This means that the amount of magnetic flux passing through the field winding 1 per unit time increases, so that when the rotation speed of the rotor 6 increases, the electromotive force generated in the field winding 1 increases. Figure 4 shows this relationship.

FIG. 4 is a diagram showing the relationship between the rotation speed of the rotor 6 and the electromotive force (voltage) generated in the field winding 1 in the power generator according to the first embodiment. The two curves shown in the figure show the electromotive force generated by the different actions, one is the electromotive force (T) due to the transformer coupling action, and the other is the electromotive force (R) due to rotation. The definition (meaning) of these two electromotive forces will be described later.

Next, the operation when the movement of the windmill 7 is taken into account in the power generator of this embodiment shown in FIG. 1 will be described with reference to FIG. 1 or FIG. In particular,

(1) When rotor 6 is stopped

Also, by the rotational driving force generated by the rotation of the windmill 7,

(2) When the rotor 6 is rotating below the synchronous speed

(3) When rotating at synchronous speed

(4) When rotating at a speed exceeding the synchronous speed,

For each state, the voltage generated in the field winding 1 and the like will be described.

(When rotor 6 is stopped)

As shown in FIG. 1, when the brush 12 rotates at the synchronous speed, the DC current flowing from the DC power supply 14 changes in the rotor winding 4 due to the movement of the brush 12. . Further, the switching of the DC current generates a synchronous rotating magnetic field in the rotor 6, and the rotating magnetic field generates induced electromotive force in the field winding 1 in synchronization with the switching of the DC current. Here, the electromotive force generated in the field winding 1 is generated based on the magnetic coupling between the field winding 1 and the rotor winding 4, and the magnitude of the electromotive force generated at this time is + Since this depends on the winding ratio of the two, this electromotive force is called the electromotive force due to the transformer coupling action.

As shown in FIG. 4, when the wind turbine 7 is stopped, an electromotive force is generated by this transformer coupling action. As described above, even when the wind turbine 7 is stopped and there is no rotational driving force and the rotor 6 is stopped, the field winding 1 undergoes a change in magnetic flux at the field poles, so that an induced electromotive force is generated.

(When the rotor 6 is rotating at a speed less than the synchronous speed)

Regarding the induced electromotive force generated in the field winding 1, when the wind turbine 7 starts to rotate from a stopped state and the rotor 6 rotates at a speed less than the synchronous speed, the following occurs. As the rotor 6 begins to rotate due to the rotational driving force of the windmill 7 and the physical rotation increases, the speed difference between the rotation of the rotor 6 and the synchronous rotation of the rotating magnetic field gradually decreases. That is, the rotation speed of the rotor 6 approaches the synchronous speed as compared with when the rotor 6 is stopped, and the transformer coupling action that occurs when the rotor 6 is stopped. The electromotive force caused by only the rotation of the rotor 6 decreases with the rotation of the rotor 6.On the other hand, the rotor 6 has a winding that is DC-excited due to the switching operation accompanying the rotation of the brushes 12 and The electromotive force generated by the rotation of the excited winding gradually increases. Note that this electromotive force is referred to as “electromotive force due to rotation” ′ to distinguish it from the above “electromotive force due to transformer coupling action”.

Also, as shown in FIG. 6, when the rotor 6 is rotating at a speed lower than the synchronous speed, the electromotive force (T) due to the transformer coupling action that is not based on the physical rotation of the rotor 6 as a whole of the power generation device ) Decreases, but the electromotive force (R) due to rotation generated based on the rotation of the rotor 6 increases. As the rotation speed of the rotor 6 increases, the conduction switching speed depending on the rotation of the brushes 12 becomes relatively slow, so that the reactance of the rotor winding 4 decreases and the rotation of the rotor winding 4 decreases. The impedance decreases. As a result, the current that generates the rotating magnetic field increases, the magnetic field becomes stronger, and the induced electromotive force in the field winding 1 also increases.

(When rotor 6 is rotating at synchronous speed)

If the rotation of the rotor 6 and the rotating magnetic field generated by the switching of conduction due to the rotation of the brushes 12 attain the same synchronous speed due to the rotational driving force of the wind turbine 7, the rotor winding 4 selected by chance Only the input / output terminals of the DC power supply conduct, and the synchronous rotation of the electromagnet (independent of the switching of the rotor winding 4) generated by the DC magnetic field based on the DC current from the DC power supply 14 forces the field winding. 1 generates an electromotive force. Since this electromotive force is generated by the magnetic flux of the electromagnet crossing the field winding 1, only the above-described electromotive force is generated by the rotation, and only the DC power flows through the rotor winding 4, so that the transformer coupling action occurs. Disappears, and the electromotive force due to this action becomes almost zero (see Fig. 4).

(When the rotor 6 is rotating beyond the synchronous speed)

When the rotation of the rotor 6 is rotated at a speed exceeding the synchronous speed due to the high speed rotation of the windmill 7 (referred to as exceeding the synchronous speed), the rotor 6 is synchronously rotated and the electromagnet of the rotor winding 4 is synchronously rotated. Also rotates at a higher speed. In other words, the rotating magnetic field caused by the current flowing through the field winding 1 and the rotor winding 4 lags behind the rotation of the rotor 6. Will rotate. Therefore, the rotor 6 itself is physically rotating even at the moment when the brush 12 that causes the change in the magnetic flux of the field winding 1 and the rotation of the rotating magnetic field does not rotate. As a result, the electromotive force generated by the rotation of the field winding 1 due to the synchronous rotation of the electromagnet of the rotor winding 4 is based on the magnetic flux change caused by the rotation of the rotor 6 that exceeds the synchronous speed. The generated electromotive force is applied to the field winding 1. In addition, the voltage generated in the field winding 1 due to the trans-coupling action is generated again when the rotation of the rotor 6 exceeds the synchronous speed, whereby the current of the rotor winding 4 is switched. This voltage increases in phase with the rotation speed of the rotor 6 in the same phase as when the speed is less than the synchronous speed (see FIG. 4).

Summarizing the above-mentioned operation (action), the voltage generated in the field winding 1 is as follows. '

(1) When the rotor 6 is stopped, only the electromotive force is generated by the transformer coupling action,

(2) When the rotor 6 is rotating at a speed less than the synchronous speed, the electromotive force due to the transformer coupling action decreases, but the electromotive force due to rotation increases,

(3) When the rotor 6 is rotating at the synchronous speed, only the electromotive force due to the rotation is generated, and the electromotive force due to the transformer coupling action is substantially zero.

(4) When the rotor 6 is rotating beyond the synchronous speed, the electromotive force due to rotation increases, and the electromotive force due to the transformer coupling rises again at the synchronous speed.

In this manner, over the entire region where the rotor 6 rotates beyond the synchronous speed from the stop state, the synchronous rotation synchronized with the period of the rotating magnetic field generated by the rotor winding 4 rotating at the synchronous speed occurs. A power generation output of a frequency can be obtained. As shown in FIG. 4, in a region where the rotor 6 is rotating below the synchronous speed, the rotor 6 behaves as a synchronous generator, and in a region where the rotor 6 is rotating beyond the synchronous speed. However, it behaves as an induction generator.

When the rotation speed of the rotor 6 increases, the current flowing in the rotor winding 4 increases. The reactance of the rotor winding 4 increases, and the current flowing in the rotor winding 4 is restricted. Limited. Therefore, as shown in Fig. 4, the electromotive force due to rotation gradually becomes saturated. On the other hand, if the current flowing through the rotor winding 4 is reduced, the electromotive force of the field winding 1 can be suppressed. In other words, a desired level of AC output can be obtained in accordance with the fluctuation of the rotation speed by positively controlling the rotor current that increases as the rotation speed of the rotor 6 increases.

As described above, according to the power generator of this embodiment, the power generator includes the rotor having the rotor winding and the stator having the stator winding, and the rotor winding has a predetermined period. Since the excitation is performed by the DC power supply through the energized contact switching means, an AC output proportional to the rotation speed of the rotor can be obtained.

[Second embodiment]

FIG. 5 is a simplified configuration diagram of a power generator according to a second embodiment of the present invention. This embodiment shows a configuration in the case of functioning as a power generation device of system cooperation. The power generator shown in Fig. 1 is configured so that the field winding 1 of the power generator shown in Fig. 1 is connected to the commercial power source, and the power output of the power generator is output to the commercial power source (system) side so that the power system can be linked. are doing. The other configuration is the same as or equivalent to the configuration of the first embodiment shown in FIG. 1, and these components are denoted by the same reference numerals.

Next, the operation of the power generator of this embodiment shown in FIG. 5 will be described. FIG. 6 (a) is a diagram showing the relationship between the rotation speed of the rotor 6 and the electromotive force (voltage) generated in the rotor winding 4 in the power generator according to the second embodiment. FIG. 6 (b) is a diagram showing the relationship between the rotation speed of the rotor 6 and the electromotive force (voltage) generated in the field winding 1 in the power generator according to the second embodiment.

In FIG. 5, as described in the first embodiment, when the brush 12 rotates at the synchronous speed, the rotor winding 4 is moved from the DC power supply 14 by the movement of the brush 12. Switching of the flowing DC current occurs. In addition, the synchronous rotating magnetic field generated by the switching of the DC current generates an electromotive force due to the transformer coupling action defined above. Note that this electromotive force is not generated even when the rotor 6 is stopped. This is the same as in the first embodiment.

On the other hand, in the power generator according to this embodiment, unlike the power generator according to the first embodiment, the AC electromotive force is applied to the rotor winding 4 due to the change of the magnetic flux by the field current of the field winding 1. The voltage that is occurring. The terminal voltage of the DC power supply 14 is applied between the two commutator pieces selected by the rotation of the brush 12. At this time, the induced electromotive force due to the field magnetic flux and the voltage applied by the DC power supply 14 are applied to the rotor winding 4 in opposite directions. The phenomenon of application in the opposite direction is a case where the speed is lower than the synchronous speed, which will be described later. Therefore, in order to generate a rotating magnetic field in the rotor winding 4, the terminal voltage of the DC power supply 14 is determined by the induced electromotive force voltage determined by the turns ratio between the field winding 1 and the rotor winding 4. It needs to be set high.

In other words, focusing on the voltage generated in the rotor winding, when the voltage generated in the rotor winding is E 2 and the DC power supply voltage is E 1, the rotor in which E 1 = E 2 is satisfied. A rotation speed P1 exists, and the rotation speed of the rotor 6 exceeds this; the region exceeding P1 is the power generation region (see Fig. 6 (a)). On the other hand, in terms of the voltage generated in the field winding, the electromotive force (R) due to rotation becomes a linearly increasing curve starting from the point P1, and the electromotive force (T) due to the transformer coupling action. Starting from a predetermined voltage determined by the winding ratio of the field winding 1 and the rotor winding 4 and decreasing linearly as in the first embodiment, the rotor 6 The rotation becomes 0 at the synchronous speed and rises again beyond the synchronous speed (see Fig. 6 (b)).

As is apparent from the above description, in the power generator of this embodiment, the rotor 6 rotates at the synchronous speed over the entire region where the rotor 6 exceeds the synchronous speed from the point P1. It is possible to obtain a power generation output of a synchronous frequency synchronized with the cycle. As shown in Figs. 6 (a) and 6-2, in the region where the rotational speed of the rotor 6 is less than the synchronous speed from P1, the behavior as a synchronous generator is exhibited, and the rotor 6 adjusts the synchronous speed. In the region where it rotates beyond, it will behave as an induction generator. . On the other hand, the operation in the region other than the above-mentioned region, that is, in the region where the rotation speed of the rotor 6 is equal to or lower than P1, is as follows. That is, in this region, as shown in FIG. 6 (a), a voltage (E 1) applied to the rotor winding 4 by the DC power supply 14 is generated in the rotor winding 4 by the field winding 1. It becomes lower than the electromotive force (E 2), and current flows into the DC power supply 14 side. Therefore, in this region, it behaves as an induction motor. At this time, it is possible to assist the rotation start of the blade near the cut-in wind speed (see Fig. 6 (b)).

If the voltage (E 1) of the DC power supply 14 is set equal to or slightly higher than the electromotive force (E 2) generated in the rotor winding 4 by the field winding 1, the DC power supply 1 Even if the voltage of (4) drops, after the voltage of DC power supply (14) is restored by the above charging current, it will not behave as an induction motor, so that this generator does not become a system load be able to.

FIG. 7 is an explanatory diagram showing the characteristics of the power generator according to the second embodiment from the viewpoint of the DC power supply 14 on the graph of the voltage generated in the rotor winding 4 shown in FIG. 6 (a). It is. Hereinafter, the characteristics of this power generation device will be described with reference to FIG. As shown in the figure, three regions based on the rotation speed of the rotor 6, namely,

(1) Area from the stop state to the rotation speed P1

(2) Range from rotation speed P1 to synchronous speed

(3) Area exceeding synchronization speed

Each area will be described separately.

(Range from stop to rotation speed P 1)

In this region, as described above, the current flows into the DC power supply 14 side. In addition, since this current flows in the direction of charging the DC power supply 14, charging can be performed if the DC power supply is a secondary battery. Further, as described above, this region is a region exhibiting the behavior as an induction motor, and is also a region in which the rotation start of the blade of the windmill 7 can be supported.

(Range exceeding the rotation speed P1 to the synchronous speed) This region is a region where the DC power supply 14 can generate power. As shown in FIG. 7, the rotor winding 4 is excited based on the difference voltage Δ VI between the DC power supply voltage (E 1) and the voltage (E 2) generated in the rotor winding 4, so that The generated voltage will increase as the speed increases.

(Area exceeding synchronization speed)

In the region above the synchronous speed, the polarity of the current flowing through the rotor winding 4 is reversed as shown in FIG. Therefore, in this region, the rotor winding 4 is excited based on the difference voltage Δν 3 between the DC power supply voltage (E 1) and the voltage (E 2) generated in the rotor winding 4, It can be understood that a larger power generation voltage is output. Note that the term V 2 indicates the difference voltage when the DC power supply voltage is set to 0 V, and indicates that power can be generated without the DC power supply voltage.

Further, from the above description, it is shown that in this region, by reversing the polarity of the DC power supply which is a secondary battery, it is possible to charge the secondary battery while enabling power generation.

Next, an experimental example using the prototype will be described. FIG. 8 is a diagram showing the configuration of an actually manufactured prototype. In the figure, the same parts as those shown in FIG. 5 are denoted by the same reference numerals. In FIG. 8, a transformer 19 for reducing the voltage of the commercial AC power supply 18 is provided, and a field circuit is formed by the field winding 1 of the generator using the output of the transformer 19 as an AC power supply. hand'! / The connection of the commercial AC power supply 18 is omitted in FIG. 8, but is also a power supply for synchronously rotating the brush 12 via the synchronous motor 9. The rotor 6 is configured to be able to rotate, for example, manually via the speed increaser 23. Further, a DC power supply 14 is connected to the commutator 8 and the brush 12 connected to a lead wire of a rotor winding (not shown). Further, in FIG. 8, a measuring instrument (for example, an oscilloscope 24) for measuring a field current and a field voltage (system voltage) is provided.

Fig. 8 shows the rotation mechanism of the brushes 12 and the power supply from the DC power supply 14 to the brushes 12 in a simplified manner, while Fig. 9 shows the windmill 7 as the prime mover. The connected example FIG. 2 is a configuration diagram illustrating the connection of the DC power supply 14 and the rotation mechanism of the brush 12 more specifically. In FIG. 9, a wind turbine 7 and a gear 23 serving as a prime mover are connected to the rotating shafts of a rotor 6 and a commutator 8. The brush 12 that contacts the commutator 8 is attached and fixed to a support member 13 including a brush holder. The support member 13 has teeth on its outer periphery that match the gear 25. Further, a slip ring (not shown in FIG. 9) is formed on the support member 13 in correspondence with the brush 12, and this slip ring is connected to the DC power supply 14. With such a structure, the brush 12 connected to the DC power supply 14 via the slip ring rotates at the synchronous speed based on the drive of the synchronous motor 9.

FIG. 10 is a diagram showing an example of a circuit configuration of the DC power supply 14. The DC power supply 14 shown in FIG. 1 has both functions of a voltage source and a current source, and has a switch 111 for outputting the output of the battery 110 as a voltage source as a voltage source. It has a resistor 112, a transistor 113, a Zener diode 114, and a bias resistor 115, which function as a current source when 1 is opened. In the figure, when the switch 11 is turned on, the voltage of the battery 110 is directly applied to the slip rings 10 and 11 (not shown) to function as a voltage source. On the other hand, when the switch 1 1 1 is opened, the current of the resistor 1 1 2 is adjusted to reverse bias by the diode 1 1 4, so that the conduction current of the transistor 1 1 3 is controlled to be constant. And can function as a current source.

FIGS. 11 to 13 are graphs showing the voltage and current waveforms by the oscilloscope 24, that is, the field voltage and the field current waveform, in the circuit shown in FIG. You. Fig. 11 shows the circuit switch 27 (Fig. 9) of the synchronous motor 9 connected to the AC commercial power supply by opening the circuit switch 26 of the DC power supply 14 without passing the rotor winding current. Fig. 9 shows the voltage V and the current I of the field winding 1 shown in Fig. 5 in a state where the coil is open, and the current I is the inductance of the field winding 1 with respect to the voltage V. Minutes late. Then, an induced electromotive force is generated in the rotor winding 4 based on the alternating magnetic field or the rotating magnetic field generated by the current I. Fig. 12 shows the circuit switches 26 and 27 of Fig. 9 turned on, the synchronous motor 9 is driven to rotate the brushes 12 at the synchronous speed, and the DC power supply (voltage source) 14 is slip ringed. And a state where a voltage is applied by connecting to the rotor winding 4 via the brush 12. In this case, the terminal voltage of the DC power supply 14 was 20 V, and the secondary voltage V of the transformer 19 was 8 V AC. In this state, the induced electromotive force generated in the rotor winding 4 depending on the number of rotor windings based on the change in magnetic flux due to the current I in the field winding 1 is lower than the DC power supply voltage. The movement of the contact position between 2 and the commutator piece 8 1 generates a rotating magnetic field in the rotor winding 4, and this rotating magnetic field changes the field flux by the field winding 1, and the field winding 1 Generates an electromotive force. As a result, as shown in FIG. 12, a field current I having almost the opposite phase to the field voltage V flows, and power is transmitted from the generator to the grid side. In other words, the rotating magnetic field formed by the exciting current from the DC power supply 14 changes the magnetic flux of the field winding 1, thereby inducing an electromotive force in the field winding 1. Note that the field current I at this time has an opposite phase with a small phase shift with respect to the field voltage V, and the excitation current by the DC power supply 14 is 15 mA, and the excitation current is extremely small.

FIG. 13 is a graph showing a waveform in which the rotor 6 is rotated by the prime mover (for example, manually) via the speed increaser 23 in the circuit state of the waveform shown in FIG. Here, as shown in the figure, the waveform of the field current I does not change in phase as compared with the waveform of FIG. 10, and the peak value increases with the rotation of the prime mover. That is, the output energy of the prime mover is converted into a generated current, and a large amplitude field current I is obtained. The frequency and phase of the field current are constant regardless of the rotation speed of the rotor 6.

As described above, the power generation device according to this embodiment has an advantage in that power generation can be constantly obtained even when there is a wide range of change in rotational driving force, and in the case of system interconnection, an apparatus such as an impeller is not required. Have. In addition, it is easy to obtain an output of a constant frequency. On the other hand, by using the DC power supply as the current source and the voltage source described above, an adjusting device for adjusting the frequency and the like and an output control can be obtained. Control equipment, protection equipment, etc., can be simplified, reducing equipment costs and maintenance. be able to.

As shown in FIG. 5, each commutator piece 81 is configured so as to be connected to each unit winding, but a current flows through the rotor winding 4 and a rotating magnetic field is applied to the rotor 6. In view of the feature of the present invention that forms a single winding, for example, if a plurality of unit windings are collectively connected to a single commutator piece 81, the number of commutator pieces can be reduced. You.

As described above, according to the present invention, there is provided a power generation device including a rotor having a rotor winding and a stator having a stator winding, and generating power from the stator winding by rotating the rotor. On the other hand, the rotor winding is excited by a DC power supply through contact switching means that is energized at a predetermined cycle, so that it is possible to generate power at a predetermined frequency.

According to the next invention, since the stator winding is connected to an AC power supply and is AC-excited, there is an effect that a system interconnection is possible.

According to the following invention, the rotor winding is formed by arranging the unit windings in the circumferential direction of the rotor core, and all the unit windings are formed as electrically coupled windings. This has the effect that it is possible to make effective use of.

According to the next invention, the rotor winding has an electric input / output terminal for each unit winding, and a current is supplied to the electric input / output terminal from the DC power supply through the contact switching means, so that each unit winding is provided. The rotor is energized at a predetermined cycle in the circumferential direction of the rotor core where the rotor is disposed, so that power can be generated regardless of the magnitude of the rotational driving force, and the effect of effectively utilizing the rotational energy can be obtained.

According to the next invention, the rotor winding has a plurality of unit windings as one set, and each set has an electric input / output terminal, and the electric input / output terminal is contact-switched from a DC power supply. Means for rotating the rotor core, on which the unit windings are arranged, in a circumferential direction at a predetermined period to generate electric power regardless of the magnitude of the rotational driving force. This has the effect of enabling effective use.

According to the next invention, the DC power supply includes both a voltage source and a current source. In other words, there is an effect that the current flowing through the rotor winding can be controlled by switching between the voltage source and the current source.

According to the next invention, the contact switching means has a commutator that rotates integrally with the rotor and a brush that rotates independently by contacting the commutator, thereby forming a rotating magnetic field having an arbitrary period. This has the effect that it can be performed.

According to the next invention, since the brush is rotated by the synchronous motor, it is possible to generate electric power in synchronization with the commercial power supply, so that there is an effect that the system can be linked. Industrial applicability

As described above, the power generation device according to the present invention can generate power regardless of the magnitude of the rotational driving force, and is suitable for a single operation or system-linked power generation device.

Claims

The scope of the claims

1. A power generating device comprising a rotor having a rotor winding and a stator having a stator winding, wherein a power generation output is obtained from the stator winding by rotation of the rotor.

The power generator according to claim 1, wherein the rotor winding is excited by a DC power supply through contact switching means that is energized at a predetermined cycle.

2. The power generator according to claim 1, wherein the stator winding is connected to an AC power supply and is AC-excited.

3. The 'rotor winding' is formed by arranging unit windings in the circumferential direction of a rotor core, and all unit windings are formed as electrically coupled windings. Clause 1

4. The rotor winding has an electrical input / output terminal for each unit winding, and the electrical input / output terminal is energized from the DC power supply via the contact switching means, 4. The power generator according to claim 3, wherein the rotor is rotationally excited at a predetermined period in a circumferential direction of the rotor core on which the rotor core is disposed.

5. The rotor winding is a set of a plurality of unit windings, each set having an electric input / output terminal, and the electric input / output terminal is connected to the DC power supply via the contact switching means. 4. The power generator according to claim 3, wherein the power is supplied to the rotor and the rotor is rotated at a predetermined cycle in a circumferential direction of a rotor core on which the unit windings are arranged.

6. The power generator according to claim 1, wherein the DC power supply includes both a voltage source and a current source.

7. The power generator according to claim 1, wherein the contact switching means includes a commutator that rotates integrally with the rotor and a brush that rotates independently in contact with the commutator. .

8. The brush according to claim 7, wherein the brush is rotated by a synchronous motor.