JP2005312212A - Energy storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an energy storage system for repeatably storing and discharging inertial energy. <P>SOLUTION: The energy storage system is provided with an electric motor having a rotor with a plurality of permanent magnets alternately magnetized in opposite polarity and continuously disposed and a stator with a plurality of electromagnetic coils disposed and facing the permanent magnets in the rotor, and a control circuit section of the stator. The control circuit section is provided with a switch means for switching between a circuit state for supplying an excitation signal for rotating the rotor to the stator and storing the inertial energy to the rotor and a circuit state for generating an electromotive force in the stator based on the inertial energy stored in the rotor and discharging it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an energy storage system, and more particularly to an energy storage system in which a rotor of an electric motor is used as a means for storing inertia energy, and the inertia energy of the rotor is electrically converted and discharged during discharge.

As this type of system, there is a wind power generation facility described in JP-A-9-317626. In order to obtain a wind power generation facility capable of generating stable electric power against changes in wind speed while reducing noise generated, as shown in the figure, the wind turbine 1 generates natural energy. Wind power is taken in and a rotational force is generated, and electric power is generated by the rotational force generated by the windmill 1 in the multipolar AC generator 4. Accordingly, the windmill rotates according to the number of poles of the multipolar alternating current generator 4. It is disclosed that noise can be reduced by reducing the number of wind turbines 1 and reducing the need for the gearbox 2 and accumulating inertial energy in the multipolar AC generator. It discloses that the flywheel for this was provided integrally. As a result, when the multipolar AC generator is rotated by the rotational force of the windmill, inertia energy is accumulated in the flywheel. Therefore, the multipolar AC generator rotates so that the rotational speed is kept constant by the inertial energy accumulated in the flywheel. Therefore, regardless of the slight change in wind speed, the multipolar AC generator The rotation speed is kept constant. That is, due to the change in wind speed, the number of revolutions of the multipolar AC generator does not change so much, and the generated power is stabilized.
JP 9-317626 A

  However, in the conventional system, the flywheel keeps the rotation speed of the alternating current generator constant, and there is no consideration for using the inertia energy accumulated in the flywheel.

  Then, an object of this invention is to provide the energy storage system which can repeat storage and discharge | release of inertial energy.

  The present invention is applied to an energy storage system in which another electric motor as an energy storage / supply means is stored as inertia energy in the rotor of the electric motor in addition to the electric motor serving as a drive source. That is, the present invention provides an electric motor including a rotor in which a plurality of permanent magnets alternately magnetized with different polarities are continuously arranged, and a stator in which a plurality of electromagnetic coils are arranged to face the permanent magnets of the rotor. And a control circuit unit for the stator, wherein the control circuit unit supplies an excitation signal for rotating the rotor to the stator and accumulates inertial energy in the rotor, and is stored in the rotor. The energy storage system includes switching means for switching between a circuit state in which an electromotive force is generated in the stator based on the inertial energy and the stator is discharged.

  The switching means of the present invention comprises means for connecting the stator to a surplus power source. The electric motor can be attached to and detached from the control circuit. The rotating shaft of the rotor is supported by a fluid bearing or a magnetic bearing with respect to the electric motor. The rotor accommodating space in the electric motor is formed in a vacuum. The stator is composed of a plurality of phases.

  1 and 2 show the principle of operation of an electric motor as a charging / discharging means used in the present invention. This motor has a configuration in which a third permanent magnet 14 serving as a rotor is interposed between a first coil set (A phase coil) 10 and a second coil set (B phase coil) 12 as a stator. Yes.

  The first coil set 10 has a configuration in which coils 16 that can be alternately excited with different polarities are arranged in order at predetermined intervals, preferably at equal intervals. The same applies to the second coil set 12. An equivalent circuit diagram of the first coil set is shown in FIG. According to FIGS. 1 and 2, as described later, the two-phase excitation coils are alternately excited with the polarity described above all the time during the starting rotation (2π). Therefore, driven means such as a rotor and a slider can be rotated and driven with high torque.

  As shown in FIG. 3 (1), a plurality of electromagnetic coils 16 (magnetic units) that are alternately excited to different polarities are connected in series at equal intervals. Reference numeral 18A is a block showing a drive circuit for applying a frequency pulse signal to the magnetic coil. When an excitation signal for exciting the coil to the electromagnetic coil 16 is sent from the drive circuit, each coil is set to be excited so that the direction of the magnetic pole is alternately changed between adjacent coils. As shown in FIG. 3 (2), the electromagnetic coils 16 may be connected in parallel. The structure of this coil is the same for the A and B phase coils.

  When a signal having a frequency for alternately switching the polarity direction of the excitation current supplied from the excitation circuit 18A to the electromagnetic coil 16 at a predetermined cycle is applied, as shown in FIG. 1 and FIG. A magnetic pattern is formed in the A-phase coil set 10 in which the polarity on the facing side changes alternately from N pole → S pole → N pole. When the frequency signal has a reverse polarity, a magnetic pattern is generated in which the polarity of the first magnetic body on the third magnetic body side alternately changes from S pole → N pole → S pole. As a result, the excitation pattern appearing in the A-phase coil set 10 changes periodically.

  The structure of the B-phase coil set is the same as that of the A-phase coil set, except that the electromagnetic coil 18 of the B-phase coil set is arranged so as to be displaced with respect to 16 of the A-phase coil set. In other words, the arrangement pitch of the coils in the A-phase coil group and the arrangement pitch of the B-phase coil group are offset so as to have a predetermined pitch difference (angle difference). This pitch difference is an angle (one rotation) at which the permanent magnet 14 moves corresponding to one cycle (2π) of the frequency of the excitation current with respect to the coils 16 and 18, for example, π / (2 * M): M is Π / 6, which is M = 3 in the number of permanent magnets (N + S), is preferable.

  Next, the permanent magnet will be described. As shown in FIGS. 1 and 2, the rotor 14 made of permanent magnets is arranged between two-phase coil sets and alternately has a plurality of permanent magnets 20 having opposite polarities (filled in black). .) Are arranged linearly (in an arc shape) at predetermined intervals, preferably at equal intervals. The arc shape includes a closed loop such as a complete circle or ellipse, an unspecified annular structure, a semicircle, or a fan shape.

  The A-phase coil set 10 and the B-phase coil set 12 are arranged at equal distances, and the arrangement pitch of the permanent magnets of the permanent magnets 14 is almost the arrangement pitch of the magnetic coils in the A-phase coil 10 and the B-phase coil 12. Is the same.

  Next, the operation of the magnetic body structure in which the above-described third magnetic body 14 is disposed between the first magnetic body 10 and the second magnetic body 12 will be described with reference to FIGS. By the excitation circuit described above (18 in FIG. 3, which will be described later), the excitation patterns as shown in FIG. 1A are applied to the electromagnetic coils 16 and 18 of the A phase coil and the B phase coil at a certain moment. Suppose that has occurred.

  At this time, a magnetic pole is generated in a pattern of → S → N → S → N → S → on each coil 16 on the surface facing the permanent magnet 14 side of the A phase coil 10, and on the permanent magnet 14 side of the B phase coil 12. In the coil 18 on the facing surface, magnetic poles are generated in a pattern of N → S → N → S → N →. The magnetic relationship between the permanent magnet and each phase coil is shown. A repulsive force is generated between the same poles, and an attractive force is applied between the different poles.

  At the next moment, as shown in (2), when the polarity of the pulse wave applied to the A-phase coil through the drive circuit 18 is reversed, the magnetic poles generated in the coil 16 of the A-phase coil 10 in (1) and permanent A repulsive force is generated between the magnetic poles of the magnet 20 and an attractive force is generated between the magnetic poles generated in the coil 18 of the B-phase coil 12 and the magnetic poles on the surface of the permanent magnet 20. As shown in FIG. 1 (1) to FIG. 2 (5), the permanent magnet 14 sequentially moves in the right direction in the figure.

  A pulse wave having a phase shifted from the excitation current of the A-phase coil is applied to the coil 18 of the B-phase coil 12, and as shown in (6) to (8) of FIG. The 18 magnetic poles and the magnetic poles on the surface of the permanent magnet 20 are repelled to move the permanent magnet 14 further to the right. (1) to (8) show the case where the rotor 14 has rotated corresponding to π, and (9) and thereafter rotate similarly corresponding to the remaining π → 2π. As described above, the rotor rotates by supplying a drive current (voltage) signal having a predetermined frequency out of phase to the A-phase coil array and the B-phase coil array.

If the A-phase coil array, the B-phase coil array, and the permanent magnet are formed in an arc shape, the magnetic structure shown in FIG. 1 constitutes a rotary motor. The parts excluding permanent magnets and electromagnetic coils such as cases and rotors are made lighter by non-magnetic resin (including carbon) and ceramics, and iron loss is reduced by opening the magnetic circuit without using a yoke. It is possible to realize a rotary drive body that is not generated and has an excellent power / weight ratio.
According to this structure, since the permanent magnet can move by receiving magnetic force from the A-phase coil and the B-phase coil, the torque generated by the permanent magnet is increased, and the torque / weight balance is excellent. It becomes possible to provide a small and light motor that can be driven. That is, if an excitation current source supplied to the A-phase coil and the B-phase coil is used from a power circuit of surplus power (night power / regenerative power), inertia energy can be stored in a rotor made of a permanent magnet. it can.

  (1) of FIG. 3 is each circuit of A-phase coil and B-phase coil when a plurality of coil arrays are formed in series, and (2) is an A-phase when a plurality of coil arrays are formed in parallel. It is each circuit of a coil and a B phase coil.

  4 is a perspective view of a motor, (1) is a perspective view of the motor, (2) is a schematic plan view of a rotor (third magnetic body), (3) is a side view thereof, and (4) is an A phase. An electromagnetic coil (first magnetic body), (5) shows a B-phase electromagnetic coil (second magnetic body). The reference numerals attached are the same as the corresponding components in the above-described drawings.

  This motor includes a pair of A-phase magnetic body 10 and B-phase magnetic body 12 corresponding to a stator, and includes the above-described third magnetic body 14 constituting the rotor, and includes an A-phase magnetic body and a B-phase magnetic body. A rotor 14 is disposed between the body and the body so as to be rotatable about a shaft 37. The rotary shaft 37 is press-fitted into the rotary shaft opening hole at the center of the rotor so that the rotor and the rotary shaft rotate integrally. As shown in FIGS. 4 (2), (4), and (5), the rotor is provided with six permanent magnets equally in the circumferential direction, and the polarities of the permanent magnets are alternately reversed. The stator is provided with six electromagnetic coils equally in the circumferential direction.

  The A-phase sensor 34A and the B-phase sensor 34B are provided on the side wall of the case inner surface of the A-phase magnetic body (first magnetic body) by shifting the phase (distance corresponding to π / 6). The A-phase sensor 34A and the B-phase sensor 34B detect the magnetic field intensity from the permanent magnet, respectively, and the frequency signal supplied to the A-phase coil 16 and the frequency signal supplied to the B-phase coil 18 have predetermined levels. It is provided to provide a phase difference.

  As a sensor, the position of the permanent magnet can be detected from the change of the magnetic pole accompanying the movement of the permanent magnet, and a Hall element utilizing the Hall effect is preferable. By using this sensor, the position of the permanent magnet can be detected by the Hall element wherever the permanent magnet is located when the distance from the S pole of the permanent magnet to the next S pole is 2π. As a Hall element, there is a type that outputs an analog value corresponding to the magnetic pole strength in addition to a type that generates a pulse.

  FIGS. 5A and 5B show different drive circuits for the A-phase magnetic body composed of the A-phase coil array and the B-phase magnetic body composed of the B-phase coil array.

  This circuit includes switching transistors TR1 to TR4 to which the output waveform of the sensor is to be applied as an exciting current to the A phase electromagnetic coil or the B phase electromagnetic coil. When the output of the phase A sensor is “H” as a signal, “L” is applied to the TR1 gate, “L” is applied to the TR2 gate, “H” is applied to the TR3 gate, and the TR4 gate is applied. Is applied with “H”. Then, TR1 and TR4 are turned on, and an excitation current as an output from the sensor having the orientation of IA1 is applied to the A-phase coil. On the other hand, when the output of the phase A sensor is “L” as a signal, “H” is applied to the TR1 gate, “H” is applied to the TR2 gate, “L” is applied to the TR3 gate, and the TR4 gate is applied. “L” is applied. Then, TR2 and TR3 are turned on, and an exciting current having the direction of IA2 is applied to the A-phase coil. Further, when TR1 and TR3 are “H” and TR2 and TR4 are “L”, the state becomes a HiZ state, and no current is supplied to the electromagnetic coil. The same applies to the excitation of the B phase coil in (2).

  FIG. 6 shows the principle of power generation during the discharge control of the motor and the principle when supplying inertial energy to the rotor. When the rotor rotates in the direction of arrow F (inertial energy), the magnetic flux in the direction of the arrow changes between the rotors of the A-phase coil and the B-phase coil, and the magnetic flux density of the coil changes periodically. The sine wave electromotive force output shown in FIG. 6 is generated from the A phase coil and the B phase coil. Since the installation phases of the two-phase coils are shifted, there is a shift between the phase of the electromotive force waveform generated in the A phase and the phase of the electromotive force waveform generated in the B phase coil. Further, by supplying an excitation signal having the phase and frequency as described above from each surplus power source to each phase coil, the rotor can be rotated to accumulate inertia energy. The rotor may be not only disk-shaped but also a spherical body (spherical motor). At this time, the inertial energy of the rotor can be accumulated in the respective rotation directions of the X, Y, and Z axes by configuring the sets of the A phase coil and B phase coil with respect to the X, Y, and Z axes. .

FIG. 7 is a more specific configuration diagram of this electric motor. The rotating shaft 37 of the rotor 300 is supported on the casing of the motor by a method such as a fluid bearing or a magnetic bearing 302 with as little friction as possible. A magnetic bearing is a bearing that supports a shaft in a non-contact manner by utilizing a repulsive force or an attractive force of a magnet. Since the shaft can be rotated in a non-contact manner, high speed and oil-free are possible. A fluid bearing is a bearing that uses a fluid such as oil or air in the bearing portion of the rotating shaft of the motor, and that that uses oil is also called an “oil bearing”. It moves smoothly only by interposing fluid such as oil and air. As this motor, it is desirable that the rotor and the motor casing be configured with a large inertia force of the rotor and no cogging-less (iron loss). In addition, by evacuating the motor, the inertial force of the rotor can be accumulated without loss. Therefore, the bearing portion is preferably sealed by a vacuum sealing means such as a magnetic fluid. The degree of vacuum than 10- ² Ps is preferred.

  FIG. 8 is a block diagram of an energy storage system according to the present invention. Reference numeral 400 denotes, for example, a generator as an external power source. Reference numeral 402 denotes a surplus power source, that is, night power from an external power source. The surplus power source is connected to a drive circuit unit 404 for rotating the rotor of the motor. This drive circuit corresponds to the motor control circuit described above, and supplies an excitation current to the stator for rotating the rotor via the switching unit 406 for rotating the electric motor as an energy storage unit. As a result, inertial energy is stored in the rotor of the motor by surplus power.

  On the other hand, when the inertia energy of the rotor is released to the outside, the switching unit 406 is switched to the regeneration side, and the stator drive circuit is used as the regeneration circuit unit 408 to store the accumulated inertia energy on the external power source or the load side. Supply as. On the load side, a plurality of loads 412 are coupled to the load switching unit 410.

  FIG. 9 is a block diagram of regenerative / power generation control by an analog type sensor (A and B phase sensors described above) including a window comparator 130 including a hysteresis adjusting electronic VR. When the output of the A-phase sensor 34A exceeds the fluctuation range of the hysteresis level, “H” of the A-phase TP or A-phase BT is output to the OR circuit 200, and this is output to the power reception control circuit described later as the A-phase regeneration permission signal. Is output. The same applies to the output of the B-phase sensor 34B. Reference numeral 202 denotes an OR circuit.

FIG. 10 is a waveform diagram showing a state in which the regenerative energy is maximum when the hysteresis adjustment electron VR is small. FIG. 11 is a waveform diagram when the regenerative energy is minimum when the hysteresis adjustment electron VR is maximum. It is the wave form diagram which showed the state which became. In the case of high load ( a state in which strong regenerative power generation is required ), the duty ratio of the regeneration permission signal of each phase becomes high, and the regeneration permission signal is “H” from the A phase and B phase coils. A regenerative current is supplied to a load (battery). This is the state of FIG. On the other hand, in the case of a low load ( a state in which weak regenerative power generation is required ), as shown in FIG. Is supplied to the load.

  FIG. 12 shows a functional block diagram of power reception control from each phase coil. When supplied according to switching of H or L of the A phase regeneration permission signal, the transistor 230 via the inverters 232A and 232B is supplied. And 232 are alternately turned on, and a regenerative current rectified by the rectifying means 231 and smoothed by the smoothing circuit 240 is generated between the + power transmission terminal and the −power transmission terminal. The same applies to the B phase coil side. FIG. 13 shows an energy conversion unit for regenerative current, 240 is a DC / DC conversion unit, 242 is a DC / AC conversion unit, and 244 is a chemical conversion unit (battery).

  FIG. 14 is a timing chart of the regenerative control, and the counter electromotive force having the above-described waveform is generated in the A-phase coil and the B-phase coil by the above-described method. The A-phase regenerative power and the B-phase regenerative power are mixed and smoothed by the smoothing circuit of FIG. 12, and the inertia energy of the rotor can be released to the outside as power.

  FIG. 15 shows a structure of an electric motor in which two rotors 300 </ b> A and 300 </ b> B laid on the rotation shaft are provided in series with the rotation shaft 37. One rotor is rotated using the A1 phase coil and the B1 phase coil as a stator. The second rotor is rotated with the B1 phase coil in common and the A2 phase coil as the stator. Since this motor has two rotors (two inertial energy storage units), the amount of inertial energy stored can be increased. 7 and 14, reference numeral 304 indicates an electrical terminal group.

The schematic diagram of the magnetic body structure concerning this invention and the principle of operation are shown. FIG. 2 shows an operation principle following FIG. It is an equivalent circuit diagram which shows the connection state of an electromagnetic coil. It is a perspective view of a motor. It is a block diagram of the drive circuit which supplies excitation current to a coil row | line | column. It is a schematic diagram which shows the charging / power generation principle of the said motor. It is a partial cross section figure which shows the detailed structure of the said motor. It is a functional block diagram which shows the system of this invention. It is a block diagram of regenerative / electric power generation control by an analog type sensor provided with a window comparator provided with electronic VR for hysteresis adjustment. It is a wave form diagram in the case of showing the state where regenerative energy is the maximum when the electron VR for hysteresis adjustment is small. It is a wave form diagram showing the state where regenerative energy became the minimum when the electron VR for hysteresis preparation was the maximum. The functional block diagram of the electric power reception control from each phase coil is shown. It is a detailed block diagram of a power receiving circuit. It is a timing chart of regenerative control. It is a partial sectional view showing an electric motor in which two rotors (inertial energy storage units) are formed in series.

Claims (6)

An electric motor including a rotor in which a plurality of permanent magnets alternately magnetized with different polarities are continuously arranged, and a stator in which a plurality of electromagnetic coils are arranged to face the permanent magnets of the rotor, and control of the stator A circuit unit,
The control circuit unit is
A charging circuit state for supplying an excitation signal for rotating the rotor to the stator and accumulating inertia energy in the rotor;
A discharge circuit state that generates an electromotive force in the stator based on inertial energy accumulated in the rotor and discharges the electromotive force;
An energy storage system comprising switching means for switching between.   2. The energy storage system according to claim 1, wherein the switching means comprises means for connecting the stator to a surplus power source.   The energy storage system according to claim 1, wherein the electric motor is detachable from the control circuit.   The energy storage system according to any one of claims 1 to 3, wherein the rotating shaft of the rotor is supported by a fluid bearing or a magnetic bearing with respect to the electric motor.   The system according to claim 1, wherein the rotor accommodating space in the electric motor is formed in a vacuum. The system according to claim 1, wherein the stator is composed of a plurality of phases.

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