Variable speed power unit and control method

Abstract

To provide a variable speed power device capable of suppressing out-of-synchronism of a synchronous machine.SOLUTION: A variable speed power device comprises: a synchronous machine including a stator in which an armature coil is provided and which forms an armature, a first rotor including a magnetic pole and a second rotor which is provided between the first rotor and the stator and drives a load; an induction voltage vector estimation unit which estimates an electric angle of an induction voltage generated in the armature based on a current and a voltage driving the synchronous machine; and a power converter which adjusts a frequency of power driving the synchronous machine based on the estimated electric angle of the induction voltage.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] This disclosure relates to a variable speed power device and a control method. [Background technology]

[0002] Figure 23 shows an example of a variable-speed power unit 9A using a typical synchronous machine 90A. The variable-speed power unit 9A consists of a synchronous machine 90A and a power converter 91 (inverter) for variable speed control. The synchronous machine 90A has a stator 901A and a rotor 902A.

[0003] Since there is a limit to the torque that the synchronous machine 90A can generate, a mechanical reducer 92 (gears) is generally used to drive heavy objects. The reducer 92 is connected to the output shaft 94 of the synchronous machine 90A and reduces the rotational speed of the synchronous machine 90A before transmitting it to the load. However, since the reducer 92 transmits power through contact between gears, maintenance of the sliding parts is required. For this reason, a variable speed power device using a synchronous machine with two rotors, a first rotor and a second rotor, has been considered as a variable speed power device that does not use a reducer. A synchronous machine with two rotors is called a magnetic geared motor. In addition to eliminating the need for maintenance of sliding parts because the rotors transmit power non-contact by magnetic force, the magnetic geared motor has the advantage of being smaller and lighter compared to a configuration using a reducer because it has fewer parts.

[0004] Figure 24 shows an example of a variable-speed power unit 9B using a magnetic geared motor 90B. The variable-speed power unit 9B consists of a magnetic geared motor 90B and a power converter 91. The magnetic geared motor 90B has a stator 901B, a first rotor 902B, and a second rotor 903B provided between the stator 901B and the first rotor 902B. The first rotor 902B may be connected to another load or power via an output shaft 94A.

[0005] The power that drives the synchronous machine 90A and the magnetic geared motor 90B is generally three-phase AC. The rotational speed of a typical synchronous machine 90A is synchronized with the frequency of the power supply that drives it. If the frequency of the power supply is changed, the rotational speed of the synchronous machine 90A will also change in synchronization with it, and the speed of the load will also change. Therefore, if the relationship between the frequency of the power supply and the speed of the load is determined in advance, the load can be moved at the desired speed by adjusting the frequency. The magnetic geared motor 90B is the same as a typical synchronous machine 90A, and the speed of the load can be changed by adjusting the frequency of the power supply that drives it.

[0006] In general synchronous machines 90A and magnetic geared motors 90B, step loss can occur when the load is excessive. As mentioned earlier, synchronous machines 90A have an upper limit to the torque they can output. If the load continuously exceeds this torque limit, the rotation of the synchronous machine 90A will lag behind the power, resulting in step loss. In a step-out state, the rotational speed of the synchronous machine 90A becomes independent of the frequency of the driving power, making it impossible to move the load at the desired speed. Moreover, step loss can cause significant vibration and noise in the load machine, potentially damaging it. Therefore, it is crucial to prevent step loss during operation of synchronous machines 90A and magnetic geared motors 90B.

[0007] In a typical synchronous machine 90A, step loss is prevented by synchronizing the voltage of the driving power with the electrical angle of the induced voltage generated in the armature (armature winding of the stator 901A) due to the rotation of the magnetic poles of the rotor 902A. More specifically, the phase of the voltage in the power line 93 is adjusted so that the difference between the electrical angle of the induced voltage and the angle of the driving power voltage, i.e., the electrical angle, does not exceed ±90 degrees. As a result, the phase or frequency of the power output by the power converter 91 reflects the rotation angle or rotation speed of the rotor 902A. For example, if the load is excessive and the rotation of the rotor 902A lags behind, it is possible to lower the driving frequency to prevent step loss.

[0008] The induced voltage is the time derivative of the magnetic flux linked to the armature. Since the linked magnetic flux rotates with the rotor 902A, if the angle of the rotor 902A is known, both the linked magnetic flux and its derivative, the induced voltage, can be determined. In a typical synchronous machine 90A, there is only one rotor 902A, so knowing the angle of one rotor 902A was sufficient to determine the induced voltage generated in the armature. Since the rotor 902A is connected to the output shaft 94, the angle of the output shaft 94, i.e., the angle of the rotor 902A, can be measured by a rotation angle sensor 95 installed on the output shaft 94. For example, Patent Document 1 describes a technique in which the angle of the output shaft is measured by a rotation angle sensor and AC power driven in synchronization with the rotation of the output shaft is commutated. In this way, the frequency of the power flowing through the power line is synchronized with the output shaft. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] International Publication No. 2015 / 186714 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The magnetic geared motor 90B has a first rotor 902B, which corresponds to the rotor 902A of the synchronous machine 90A, as well as a second rotor 903B. For example, Patent Document 1 further describes a magnetic geared motor having a first rotor and a second rotor, wherein power is output from the second rotor. In other words, in the magnetic geared motor described in Patent Document 1, the rotation angle sensor that measures the angle of the output shaft measures the angle of the second rotor.

[0011] In a magnetic geared motor, the induced voltage generated in the armature depends not only on the angle of the second rotor but also on the angle of the first rotor. Therefore, in the technique described in Patent Document 1, an error may occur due to ignoring the influence of the first rotor. Then, when the induced voltage is determined by the angle of the first rotor rather than the second rotor, there is a possibility of detuning.

[0012] The present disclosure has been made in view of such problems, and provides a variable speed power device and a control method capable of suppressing detuning of a synchronous machine.

Means for Solving the Problems

[0013] According to one aspect of the present disclosure, a variable speed power device includes a stator provided with an armature winding to form an armature, a first rotor having magnetic poles, and a second rotor provided between the first rotor and the stator to drive a load, a synchronous machine having; an induced voltage angle estimation unit that estimates an electrical angle of an induced voltage generated in the armature based on a current and a voltage for driving the synchronous machine; and a power converter that adjusts a frequency of power for driving the synchronous machine based on the estimated electrical angle of the induced voltage.

[0014] According to one aspect of the present disclosure, a control method for a synchronous machine having a stator provided with an armature winding to form an armature, a first rotor having magnetic poles, and a second rotor provided between the first rotor and the stator to drive a load includes: estimating an electrical angle of an induced voltage generated in the armature based on a current and a voltage for driving the synchronous machine; and adjusting a frequency of power for driving the synchronous machine based on the estimated electrical angle of the induced voltage.

Advantages of the Invention

[0015] According to the variable speed power device and the control method according to the present disclosure, detuning of the synchronous machine can be suppressed.

Brief Description of the Drawings

[0016] [Figure 1]This figure shows the functional configuration of a variable speed power device according to the first embodiment of this disclosure. [Figure 2] This is a cross-sectional view of a synchronous machine according to the first embodiment of this disclosure. [Figure 3] This is a diagram illustrating the concept of operation of a power converter according to the first embodiment of this disclosure. [Figure 4] This figure shows the functional configuration of a variable speed power device according to the second embodiment of this disclosure. [Figure 5] This is a cross-sectional view of a first rotor according to a third embodiment of the present disclosure. [Figure 6] This is a cross-sectional view of a first rotor according to a fourth embodiment of the present disclosure. [Figure 7] This is a perspective view of a first rotor according to a fourth embodiment of the present disclosure. [Figure 8] This figure shows the functional configuration of a variable speed power device according to the fifth embodiment of this disclosure. [Figure 9] This figure shows the functional configuration of a variable speed power device according to the sixth embodiment of this disclosure. [Figure 10] This figure shows the functional configuration of a variable speed power device according to the seventh embodiment of this disclosure. [Figure 11] This figure shows the functional configuration of a variable speed power device according to the eighth embodiment of this disclosure. [Figure 12] This figure shows the functional configuration of a power converter according to the eighth embodiment of this disclosure. [Figure 13] This figure shows the functional configuration of a variable speed power device according to the ninth embodiment of this disclosure. [Figure 14] This diagram shows the functional configuration of the power converter according to the ninth embodiment. [Figure 15] This figure shows an example of an induced voltage vector according to the ninth embodiment of this disclosure. [Figure 16] This figure shows the functional configuration of a variable speed power device according to the tenth embodiment of this disclosure. [Figure 17] This is a diagram illustrating the operation of a power converter according to the tenth embodiment of this disclosure. [Figure 18]This figure shows an example of a load angle according to the tenth embodiment of this disclosure. [Figure 19] This figure shows the functional configuration of a variable speed power device according to the eleventh embodiment of this disclosure. [Figure 20] This figure shows the functional configuration of a variable speed power device according to the twelfth embodiment of this disclosure. [Figure 21] This figure shows the functional configuration of a power converter according to the twelfth embodiment of this disclosure. [Figure 22] This figure shows an example of the hardware configuration of the equipment constituting a variable speed power device according to at least one embodiment of the present disclosure. [Figure 23] The first figure shows an example of a conventional variable-speed power unit. [Figure 24] The second figure shows an example of a conventional variable-speed power unit. [Modes for carrying out the invention]

[0017] <First Embodiment> Hereinafter, a variable-speed power unit 1 according to the first embodiment of this disclosure will be described with reference to the figures.

[0018] (Functional configuration of variable speed power unit) Figure 1 is a diagram showing the functional configuration of a variable speed power device according to the first embodiment of this disclosure. As shown in Figure 1, the variable speed power unit 1 comprises a synchronous machine 2, a control device 3, and a power converter 4.

[0019] Synchronous machine 2 is a magnetic geared motor. A magnetic geared motor also functions as a magnetic geared generator. Therefore, in this embodiment, synchronous machine 2 represents both the roles of a motor and a generator. In the following section, an example of using synchronous machine 2 as a motor will be described.

[0020] Figure 2 is a cross-sectional view of a synchronous machine according to the first embodiment of this disclosure. As shown in Figures 1 and 2, the synchronous machine 2 has a stator 21, a first rotor 22, a second rotor 23, an output shaft 24, and an output shaft 24A.

[0021] The stator 21 is an annular structure that surrounds the first rotor 22 and the second rotor 23. The stator 21 forms an armature by providing an armature winding 212 on each of the multiple teeth 211 that protrude radially inward.

[0022] The first rotor 22 is a rotor that rotates around the rotation axis O. The first rotor 22 has a core 221 made of a soft magnetic material and a plurality of magnetic poles 222. The magnetic poles 222 are, for example, permanent magnets. In the example in Figure 2, the number of magnetic poles of the first rotor 22 is 4, but it is not limited to this. In other embodiments, the number of magnetic poles of the first rotor 22 may be changed. The first rotor 22 is connected to another load or power via the output shaft 24A.

[0023] Furthermore, while the example in Figure 2 shows a configuration in which permanent magnets are arranged to completely cover the outer circumferential surface of the core 221 of the first rotor 22, the configuration is not limited to this. In other embodiments, the first rotor 22 may have a configuration in which multiple magnetic poles (salliance poles) protruding radially outward from the outer circumferential surface are integrally formed with the core 221. In this case, the first rotor 22 does not need to be provided with magnets or electromagnets. In yet another embodiment, the core 221 of the first rotor 22 may be formed from a soft magnetic material such as magnetic steel plate, and magnets may be arranged at intervals on the outer circumferential surface of the core 221. That is, instead of covering the entire outer circumferential surface of the core 221 with magnets as in the example in Figure 2, the soft magnetic material may be exposed between adjacent magnets (boundaries).

[0024] The second rotor 23 is provided between the stator 21 and the first rotor 22. The second rotor 23 is an annular structure surrounding the first rotor 22 and rotates around the rotation axis O. As shown in Figure 1, the second rotor 23 is connected to the output shaft 24 and drives the load connected to the output shaft 24. Also, as shown in Figure 2, the second rotor 23 has magnetic poles 231 and non-magnetic parts 232 arranged alternately in the circumferential direction. The magnetic poles 231 are made of a magnetic material (soft magnetic material or hard magnetic material). The non-magnetic parts 232 are made of a non-magnetic material. Note that the non-magnetic parts 232 may be voids created by cutting out a magnetic material in the radial direction.

[0025] Furthermore, as shown in the example in Figure 2, multiple magnets 213 may be arranged in an annular pattern between the stator 21 and the second rotor 23 (on the inner circumferential surface of the teeth 211 of the stator 21). In other embodiments, the magnets 213 may be omitted.

[0026] The control device 3 is a device for controlling the operation of the synchronous machine 2. The control device 3 according to this embodiment has an induced voltage angle estimation unit 31. The induced voltage angle estimation unit 31 has a flux linkage estimation unit 310 and a calculation unit 311.

[0027] The flux linkage estimation unit 310 estimates the angle of the magnetic flux linked to the armature winding 212 based on the angle of the first rotor 22 (first angle) and the angle of the second rotor 23 (second angle). In this embodiment, the flux linkage estimation unit 310 obtains the angle of the first rotor 22 from a first angle sensor 13 provided on the first rotor 22 and the angle of the second rotor 23 from a second angle sensor 14 provided on the second rotor 23.

[0028] The calculation unit 311 calculates the electrical angle of the armature induced voltage based on the estimated magnetic flux angle. The calculated electrical angle of the induced voltage is output to the power converter 4.

[0029] The power converter 4 is electrically connected to the synchronous machine 2 via the power line 11 (the armature winding 212 of the synchronous machine 2). Based on the power frequency command value and the electrical angle of the induced voltage input from the control device 3, the power converter 4 adjusts the frequency, voltage, and current of the power that drives the synchronous machine 2 using techniques such as V / f control and vector control.

[0030] (Operation of the control device) Next, the operation of the control device 3 according to this embodiment will be described in detail. As an example, a configuration in which permanent magnets are arranged so as to cover the entire outer surface of the core 221 of the first rotor 22 will be specifically described. First, the angle estimation of the magnetic flux linkage performed by the magnetic flux linkage estimation unit 310 will be described. In general synchronous machines, there is no second rotor, so the angle of the magnetic flux linkage is immediately determined from the first rotor. For this reason, angle estimation is not necessary. Angle estimation is effective for devices that have multiple rotors, such as magnetic geared motors. To simplify the explanation, if the angle of the first rotor is taken as a reference to the direction in which its magnetomotive force is maximum, the magnetomotive force at a position advanced by an angle θ from the reference direction of the first rotor can be approximated by the following equation (1). Here, p1 is the number of poles of the first rotor. For rotors with magnets, the value obtained by multiplying the mechanical angle of the rotor by the number of poles divided by 2 is called the electrical angle. While the rotor rotates mechanically once, the magnetomotive force alternates between p1 / 2 according to the electrical angle.

[0031]

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[0032] Assume that the angle of the first rotor 22 is θ1 when measured with respect to one armature of the stator 21. In this case, from equation (1), the magnetomotive force in the direction advanced θ from the reference point of the stator 21 is given by the following equation (2).

[0033]

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[0034] The second rotor 23 has magnetic poles 231 and non-magnetic parts 232 arranged alternately in the circumferential direction. Therefore, the ease with which magnetic flux passes through the second rotor 23, i.e., permeance, changes with the angle of the second rotor 23, or in other words, the circumferential position on the second rotor 23. The angle of the second rotor can be approximated by the following equation (3) when the circumferential direction in which the permeance is maximized is used as the reference direction for the second rotor. Here, p2 is the number of poles of the second rotor 23. In a rotor that obtains power by changing permeance, the electrical angle is obtained by multiplying the rotor angle (mechanical angle) by the number of poles. When the rotor completes one mechanical revolution, the permeance repeats a period of increasing or decreasing by p2 times. 20 ≥B 21 It is >0. This represents a physical constraint that permeance is always positive.

[0035]

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[0036] Suppose the angle of the second rotor 23 is measured to be θ2, with respect to one armature of the stator 21. In this case, the permeance in the direction advanced θ from the reference point of the stator 21 is given by the following equation (4).

[0037]

number

[0038] When the angle of the first rotor 22 is θ1 and the angle of the second rotor 23 is θ2, the magnetic flux linked to the armature in the direction advanced θ from the reference point of the stator 21 is expressed by the following equation. The symbol φ(θ)|θ1,θ2 represents the magnetic flux φ at angle θ, given the prior information that "the angle of the first rotor 22 is θ1 and the angle of the second rotor 23 is θ2".

[0039]

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[0040]

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[0041] In this explanation, we have used a synchronous machine 2 of the type in which a magnet 213 is not provided between the second rotor 23 and the teeth 211 of the stator 21 as an example, but similar calculations can be performed for other types of synchronous machines 2 (types in which a magnet 213 is provided, as shown in Figure 2).

[0042] Furthermore, in this case, the flux linkage estimation unit 310 calculated the direction of the magnetic flux from constants such as A1, B20, and B21. However, it is not limited to this method; the direction of maximum flux can also be determined by numerical analysis or experimentation. For example, a table may be prepared in advance to estimate the armature's flux linkage from the angles of the first rotor 22 and the second rotor 23. In this case, the flux linkage estimation unit 310 measures the angles θ1 of the first rotor 22 and θ2 of the second rotor 23, respectively, and calculates the angle of the flux linkage from the prepared table.

[0043] Furthermore, the electrical angle of the induced voltage (generally the flux linkage advanced by π / 2 in electrical angle) can be determined from the angle of the flux linkage. The calculation unit 311 calculates the electrical angle of the induced voltage based on the angle of the flux linkage estimated by the flux linkage estimation unit 310. The calculated electrical angle of the induced voltage is output to the power converter 4.

[0044] (Operation of the power converter) Figure 3 is a diagram illustrating the concept of operation of a power converter according to the first embodiment of the present disclosure. In this embodiment, the output shaft is connected to a second rotor. The power converter 4 is an example of controlling the synchronous machine 2 by vector control based on the electrical angle of the induced voltage. Vector control generally adjusts the output torque of the synchronous machine 2. The command value of the output torque is output by a speed controller positioned above the vector control. The speed controller receives a frequency command of power representing the speed command and the electrical angular frequency of the load shaft as input, and outputs a torque command by, for example, proportional-integral control calculation. In this embodiment, the second rotor 23 corresponds to the load shaft. The vector controller outputs a voltage command and a frequency command based on the electrical angle of the induced voltage and the current of the power output by the power converter 4. The power converter 4 supplies power to the armature according to the voltage command and frequency command.

[0045] (Effects and Benefits) As described above, the variable speed power device 1 according to this embodiment includes an induced voltage angle estimation unit 31 that estimates the electrical angle of the induced voltage generated in the armature from the angle of the first rotor 22 and the angle of the second rotor 23 of the synchronous machine 2, and a power converter 4 that adjusts the frequency of the power driving the synchronous machine 2 based on the estimated electrical angle of the induced voltage. Furthermore, the induced voltage angle estimation unit 31 according to this embodiment includes a linked flux estimation unit 310 that estimates the angle of the magnetic flux linked to the armature winding 212 based on the angle of the first rotor 22 and the angle of the second rotor 23, and a calculation unit 311 that calculates the electrical angle of the induced voltage based on the angle of the linked flux and the angle of the second rotor 23.

[0046] When vector control is employed in the power converter 4, the responsiveness of the mechanical output of the synchronous machine 2 is improved compared to when V / f control is employed. Vector control requires the electrical angle of the induced voltage. However, in conventional technology, the electrical angle of the induced voltage is unknown, and the responsiveness inherent in vector control could not be obtained. Alternatively, because the electrical angle of the induced voltage was inaccurate, the first rotor would vibrate and sometimes lose synchronism. According to this embodiment, vector control is performed using the electrical angle of the induced voltage estimated based on the angles of the first rotor and the second rotor. This improves the responsiveness of the magnetic geared motor or prevents step loss due to the inherent rapid response of vector control.

[0047] <Second Embodiment> Next, a variable-speed power unit 1 according to the second embodiment of this disclosure will be described. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0048] Figure 4 is a diagram showing the functional configuration of a variable speed power device according to the second embodiment of this disclosure. As shown in Figure 4, the control device 3 according to this embodiment further includes a first angle estimation unit 32. The first angle estimation unit 32 uses, for example, adjustment constants β1 and β2 predetermined by testing or analysis to determine the angle of the second rotor 23 (second angle) measured by the second angle sensor 14 and the voltage angle θ. V Based on this, the angle of the first rotor 22 (first angle) is estimated.

[0049] (Operation of the control device) Next, the operation of the control device 3 according to this embodiment will be described in detail. The control device 3 according to this embodiment uses a first angle estimation unit 32 that estimates the angle of the first rotor 22 from the angle of the second rotor 23 and the voltage and current of the three-phase AC, instead of the first angle sensor 13 of the first rotor 22.

[0050] θ2 is the measured angle of the second rotor 23, and n is the number of rotations the first rotor makes when the second rotor 23 completes one rotation under no load. 12 Expressed as such, the angle of the first rotor 22 can be approximated by the transfer function shown in equation (7) below, based on the measured angle θ2 of the second rotor 23.

[0051]

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[0052] Transfer function parameter n 12 J, C, and K are values ​​specific to the synchronous machine 2 and can be determined through prior testing. 12The value can be calculated from the number of poles p2 of the second rotor 23 and the number of poles p1 of the first rotor. When both the magnetic poles 222 of the first rotor 22 and the magnetic poles 231 of the second rotor 23 have permanent magnets or electromagnets, or when neither of them has a permanent magnet or an electromagnet, "n 12 = p2 / p1". When only the magnetic poles 222 of the first rotor 22 have a permanent magnet or an electromagnet, "n 12 = 2p2 / p1". When only the magnetic poles 231 of the second rotor 23 have a permanent magnet or an electromagnet, "n 12 = p2 / (2p1)". The first angle estimation unit 32 performs the calculation of this transfer function. If it is found in a preliminary test that parameters such as the parameter K of the transfer function vary greatly depending on the output torque of the synchronous machine, the values such as K may be changed according to the operation of the synchronous machine.

[0053] The operations of the magnetic flux linkage estimation unit 310 and the calculation unit 311 are the same as those in the first embodiment.

[0054] (Function and effect) As described above, the variable speed power device 1 according to the present embodiment further includes a first angle estimation unit 32 that estimates the angle of the first rotor 22 based on the angle of the second rotor 23.

[0055] By doing so, it is possible to eliminate the first angle sensor 13 for measuring the angle of the first rotor 22 and its wiring. Thereby, it is possible to realize the compactification and cost reduction of the variable speed power device 1.

[0056] <The third embodiment> Next, the variable speed power device 1 according to the third embodiment of the present disclosure will be described. In this embodiment, the output shaft is connected to the second rotor. The same reference numerals are given to the components common to the above-described embodiments, and the detailed description thereof is omitted.

[0057] (Configuration of the first rotor) FIG. 5 is a cross-sectional view of the first rotor according to the third embodiment of the present disclosure. As shown in Figure 5, the first rotor 22 according to this embodiment has a weight-reducing portion 223 formed around the rotation axis O. The weight-reducing portion 223 is formed by removing material from the core 221 of the first rotor 22.

[0058] In the second embodiment, instead of the first angle sensor 13 of the first rotor 22, the first angle estimation unit 32 estimated the angle of the first rotor 22. That is, the angle of the first rotor 22 was replaced with an estimated value rather than the actual value. The estimated value of the angle of the first rotor 22 is calculated using the equation of motion consisting of the moment of inertia of the first rotor 22 and the electromagnetic torque acting on the first rotor 22. The accuracy of the estimated value of the angle of the first rotor 22 is determined by the natural frequency ω, which is determined from the characteristic root of the equation of motion. n The higher the value of and the higher the damping ratio ζ, the better the performance. These can be achieved by reducing the moment of inertia of the second rotor 23.

[0059] If we express the moment of inertia as J [kgm²], the mechanical angular gradient of the electromagnetic torque as K [Nm / rad], and the mechanical angular velocity gradient of the electromagnetic torque as C [Nm / (rad / s)], then the characteristic equation is: "Js 2 It can be expressed as "+Cs+K=0". The characteristic root is "-C±√(C 2 The value is -4KJ) / 2J. Natural angular frequency ω n The coefficient of force is "√(K / J)", and the damping ratio ζ is "C / 2√(KJ)".

[0060] If the first rotor 22 is not lightened, the moment of inertia J is large, so the natural angular frequency ω n The value becomes small, the damping ratio ζ becomes small, and the accuracy of estimating the angle of the first rotor 22 may deteriorate.

[0061] In this embodiment, the moment of inertia J of the first rotor 22 is reduced, increasing both the natural angular frequency and the damping ratio, and the transfer function (equation 7) described in the second embodiment is changed to a damped first-order lag response as shown in equation (8) below, thereby reducing the error in angle estimation in the first angle estimation unit 32.

[0062]

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[0063] To reduce J, a weight-reducing portion 223 is formed in the core 221 (soft magnetic material) of the first rotor 22, thereby reducing the moment of inertia of the first rotor 22.

[0064] The weight-reducing portion 223 is greater in the center of the circumferential spread of the magnetic pole 222 (the center of the magnetic pole 222) and less in the space between adjacent magnetic poles (the middle of the magnetic poles). In other words, the radial length of the weight-reducing portion 223 (length from the axis of rotation O) is set to be longer as it approaches the center of the magnetic pole 222 and shorter as it approaches the midpoint between two adjacent magnetic poles 222.

[0065] The first rotor 22 is unaffected by external loads. When there is no load, the rotor of a synchronous machine balances at the angle that maximizes the magnetic flux. At this time, as shown in Figure 5, the main component of the magnetic flux is radial at the center of the magnetic pole, with little circumferential component. Therefore, deep material removal at the center of the magnetic pole does not hinder the magnetic flux.

[0066] Regarding the weight-reducing section 223, the fact that it is greater in the center of the magnetic pole 222 and less in the middle of the magnetic pole means, specifically, as shown in Figure 5, that the length d of the weight-reducing section is the angle θ measured from the center of the magnetic pole. m When measured against, the following equation (9) holds true.

[0067]

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[0068] Here, E(d(θ m E(d(θ)) is the average value of d. If there are multiple weight-reducing holes, calculate d for each individual weight-reducing hole and sum them up to get E(d(θ)). m ))

[0069] (Effect, Action) As described above, in the variable speed power device 1 according to this embodiment, the first rotor 22 has a weight-reducing portion 223 around the rotation axis O.

[0070] By doing so, the moment of inertia of the first rotor 22 can be reduced and the damping ratio can be increased. As a result, the accuracy of the angle estimation of the first rotor 22 in the first angle estimation unit 32 can be improved.

[0071] In this embodiment, since the angle of the first rotor 22 can be estimated with high accuracy, the processing of the flux linkage estimation unit 310 may be simplified. Specifically, the flux linkage estimation unit 310 may estimate the angle of the flux linkage by approximating the electrical angle of the first rotor 22 with a weighted sum of the electrical angle of the second rotor 23 and the electrical angle of the voltage.

[0072] Furthermore, the radial length of the weight-reducing portion 223 is set to increase as it approaches the center of the magnetic pole 222.

[0073] In this way, the weight-reducing portion 223 can be formed without obstructing the magnetic flux.

[0074] <Fourth Embodiment> Next, a variable-speed power unit 1 according to a fourth embodiment of the present disclosure will be described. In this embodiment, the output shaft is connected to a second rotor. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0075] (Configuration of the first rotor) Figure 6 is a cross-sectional view of the first rotor according to the fourth embodiment of the present disclosure. Figure 7 is a perspective view of the first rotor according to the fourth embodiment of this disclosure. As shown in Figures 6 and 7, the first rotor 22 according to this embodiment further has a damping winding 224 wound so as to be linked with a magnetic flux that penetrates the meridional plane including the center of the magnetic pole 222.

[0076] Figure 7 is an image of a portion of the first rotor 22 cut along the meridional plane in the circumferential direction. To wind the damping winding 224 so that the magnetic flux passing through the meridional plane containing the center of the magnetic pole 222 links, for example, the conductor can be wound in the meridional plane containing the center of the magnetic pole, as shown in Figure 7. In the example in Figure 7, the damping winding 224 is wound around the deepest part of the hollowed-out section 223 (the inner circumferential surface of the core 221) and the radial circumferential surface of the core 221.

[0077] The damping coefficient additionally generated by the braking winding 224 is C d With this in mind, the transfer function of the first rotor 22 is expressed by the following equation (10).

[0078]

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[0079] In addition, in this embodiment, J is reduced by removing material, similar to the third embodiment, so the transfer function is given by the coefficient n as shown in equation (11). 12 This is approximated by the fact that the first rotor 22 can follow the angle of the second rotor 23 without delay, thus more reliably suppressing step loss.

[0080]

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[0081] (Effect, Action) As described above, in the variable speed power device 1 according to this embodiment, the first rotor 22 further has a damping winding 224 wound so as to link with the magnetic flux that penetrates the meridional plane including the center of the magnetic pole 222.

[0082] In this way, the variable speed power unit 1 becomes even less prone to losing synchronism than in the third embodiment.

[0083] <Fifth Embodiment> Next, a variable-speed power unit 1 according to a fifth embodiment of the present disclosure will be described. In this embodiment, the output shaft is connected to a second rotor. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0084] (Functional configuration of variable speed power unit) Figure 8 shows the functional configuration of a variable speed power device according to the fifth embodiment of this disclosure. As shown in Figure 8, the variable speed power unit 1 according to this embodiment further includes a first motor 5 in addition to the configuration according to the second embodiment. The first motor 5 has a rotor 51 (third rotor) and an electric wire 52. The first motor 5 is, for example, an induction motor. The first motor 5 is configured to have the same synchronous speed as the synchronous machine 2, or to have the same number of poles as the synchronous machine 2.

[0085] The rotor 51 of the first electric motor 5 is mechanically connected to the first rotor 22 of the synchronous machine 2.

[0086] The electric wire 52 is electrically connected in parallel with the armature winding 212 of the synchronous machine 2.

[0087] (Operation of the first motor and power converter) In the third and fourth embodiments, the damping ratio of the motion of the first rotor 22 was improved by the weight-reducing portion 223 and the damping winding 224 of the first rotor 22. However, because the first rotor 22 is located inside the synchronous machine 2, space constraints may prevent sufficient improvement with only the weight-reducing portion 223 and the damping winding 224.

[0088] Therefore, in this embodiment, the functions of the weight-reducing section 223 and the damping winding 224 according to the third and fourth embodiments are replaced by an externally located first motor 5. The first motor 5 is connected to the power converter 4 and consumes a portion of the three-phase AC power supplied by the power converter 4 to the synchronous machine 2. Due to the properties of induction motors, the first motor generates a damping force proportional to the difference between the synchronous speed of the first motor 5, which is determined by the power frequency, and the rotational speed of the first motor 5. Since the first motor 5 is connected to the first rotor 22, the generated damping force also acts as a damping force on the first rotor. Therefore, the same effect as increasing the damping coefficient C of the first rotor can be obtained.

[0089] Since the first rotor 22 of the synchronous machine 2 is not connected to an external load, it is not subjected to any load. Therefore, the first motor 5 can be small and sufficient.

[0090] (Effects and Benefits) As described above, the variable speed power device 1 according to this embodiment further comprises a first electric motor 5 having a rotor 51 (third rotor) which has the same number of poles as the first rotor 22 of the synchronous machine 2 and is mechanically connected to the first rotor 22, and an electric wire 52 which is electrically connected in parallel to the armature winding 212 of the synchronous machine 2.

[0091] This improves the accuracy of the first angle estimation unit 32. As a result, the variable speed power unit 1 can follow more rapid load changes, and the range in which step loss can be avoided can be expanded. In other words, step loss can be suppressed even more robustly.

[0092] <Sixth Embodiment> Next, a variable-speed power unit 1 according to a sixth embodiment of the present disclosure will be described. In this embodiment, the output shaft is connected to a second rotor. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0093] (Functional configuration of variable speed power unit) Figure 9 is a diagram showing the functional configuration of a variable speed power device according to the sixth embodiment of this disclosure. As shown in Figure 9, the variable speed power unit 1 according to this embodiment further includes a reduction gear 6 in addition to the configuration according to the second embodiment.

[0094] The reduction gear 6 has a coupling 63 that connects the first rotor 22 and the second rotor 23 of the synchronous machine 2. The coupling 63 is either an elastic coupling or a viscous coupling. The reduction gear 6 also has a first gear 61 and a second gear 62. The first gear 61 is connected to the output shaft 24 of the synchronous machine 2. Therefore, the first gear 61 rotates at the same speed as the second rotor 23. The second gear 62 further transmits the power of the second rotor 23 of the synchronous machine 2, which has been transmitted from the first gear 61, to the coupling 63. The coupling 63 is connected to the first rotor 22 via a shaft 64. As a result, the angle of the first rotor 22 follows the angle of the second rotor 23. If the speed ratio of the reduction gear 6 is equal to the speed ratio of the first rotor to the second rotor, the reduction gear will operate under no load in a steady state. Furthermore, only when a transient speed difference occurs between the two rotors, the viscoelastic coupling generates a damping force corresponding to the speed difference. This has the same effect as increasing the damping coefficient C of the first rotor 22. This suppresses vibration of the first rotor 22 relative to the second rotor 23. As a result, the accuracy of the first angle estimation unit 32 in estimating the angle of the first rotor 22 can be improved.

[0095] Figure 9 shows an example in which the components of the reduction gear 6 (first gear 61, second gear 62, coupling 63, and shaft 64 connecting the coupling 63 to the first rotor 22) are arranged outside the synchronous machine 2, but the configuration is not limited to this. In other embodiments, the reduction gear 6 may be composed of, for example, planetary gears and arranged inside the synchronous machine 2.

[0096] (Effects and Benefits) As described above, the variable speed power unit 1 according to this embodiment further comprises a reduction gear 6 connected to a synchronous machine. The reduction gear 6 has a coupling 63 that connects the first rotor 22 and the second rotor of the synchronous machine 2.

[0097] In this way, the variable-speed power unit 1 can suppress the irregular vibration of the first rotor 22 of the synchronous machine 2 relative to the second rotor 23. This improves the accuracy of the first angle estimation unit 32 in estimating the angle of the first rotor 22.

[0098] <Seventh Embodiment> Next, a variable-speed power unit 1 according to a seventh embodiment of the present disclosure will be described. In this embodiment, the output shaft is connected to a second rotor. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0099] (Functional configuration of variable speed power unit) Figure 10 is a diagram showing the functional configuration of a variable speed power device according to the seventh embodiment of this disclosure. As shown in Figure 10, the variable speed power unit 1 according to this embodiment further includes a second electric motor 7 and a second power converter 8 in addition to the configuration according to the second embodiment.

[0100] The second motor 7 has a rotor 71 (a fourth rotor). The rotor 71 is mechanically connected to the first rotor 22 of the synchronous machine 2. Similar to the first motor 5 in the fifth embodiment, the second motor 7 is, for example, a small induction motor or a small synchronous motor.

[0101] The second power converter 8 supplies power to the second motor 7 by adjusting the frequency of the power driving the second motor 7 so that the rotational speed of the second rotor 23 matches the rotational speed of the first rotor of the synchronous machine 2. Furthermore, the second power converter 8 may also supply power to the second motor 7 to assist the synchronous machine 2.

[0102] (Operation of the second motor and the second power converter) As shown in Figure 10, the second motor 7 is connected to the first rotor 22 of the synchronous machine 2. The second motor 7 is powered by the second power converter 8. The second power converter 8 converts the rotational speed [rps] of the second rotor 23, which is obtained from the time derivative of the angle of the second rotor 23 of the synchronous machine 2, to p1n12 Multiplying by 2 generates the target frequency for the second power converter 8 so that the rotational speed of the second rotor 23 becomes the synchronous rotational speed of the first rotor 22. The second power converter 8 adjusts the frequency and phase of the power driving the second motor 7 so that the rotational speed of the first rotor 22 matches the synchronous rotational speed. Furthermore, the second power converter 8 may additionally advance the voltage of the power driving the second motor 7 to assist the synchronous machine 2.

[0103] (Effects and Benefits) As described above, the variable speed power device 1 according to this embodiment further comprises a second electric motor 7 mechanically connected to the first rotor 22 of the synchronous machine 2, and a second power converter 8 that adjusts the frequency of the power driving the second electric motor 7 to match the speed of the second rotor 23 of the synchronous machine 2. The power supplied to the second electric motor 7 by the second power converter 8 acts as a damping force when the second electric motor 7 and the first rotor 22 move relative to the second rotor 23, thereby limiting this relative motion. Furthermore, assisting the synchronous machine 2 with the second power converter 8 and the second electric motor 7 improves the load driving capacity.

[0104] In this way, the variable-speed power unit 1 can suppress the irregular vibration of the first rotor 22 of the synchronous machine 2 relative to the second rotor 23. This improves the accuracy of the first angle estimation unit 32 in estimating the angle of the first rotor 22. As a result, the variable-speed power unit 1 can follow more rapid load changes and expand the range in which step loss can be avoided. In other words, step loss can be suppressed even more robustly.

[0105] <Eighth Embodiment> Next, a variable-speed power unit 1 according to the eighth embodiment of this disclosure will be described. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0106] (Functional configuration of variable speed power unit) Figure 11 is a diagram showing the functional configuration of a variable speed power device according to the eighth embodiment of this disclosure. As shown in Figure 11, the variable speed power unit 1 according to this embodiment does not have a flux linkage estimation unit 310. The flux linkage estimation unit 310 performed vector control in the power converter 4 based on the electrical angle of the induced voltage by the first rotor 22 and the second rotor 23. In this embodiment, by using V / f control instead of vector control in the power converter 4, the estimation of the electrical angle of the induced voltage is made unnecessary. It is known that the rotational speed of a synchronous machine follows the synchronous speed of the drive power frequency with a time delay and is ultimately settled at the synchronous speed. The magnetic geared motor of this application also belongs to the category of synchronous machines and therefore possesses this property.

[0107] Therefore, if the frequency of the drive power is not changed abruptly in time, the rotation of the magnetic geared motor will follow the synchronous speed determined by the frequency of the drive power, albeit with a lag, and speed adjustment can be achieved relatively easily by changing the frequency of the drive power. However, if the frequency of the drive power is changed abruptly in time, the rotational lag becomes excessive, causing the motor to lose synchronism and the original function of the synchronous machine is lost.

[0108] A magnetic geared motor has a first rotor and a second rotor, so each rotor is susceptible to step loss. Step loss occurs when the offset between the electrical angle of the drive power voltage and the electrical angle of the rotor exceeds ±90°. Therefore, the offsets of each rotor are compared, and the drive power voltage is adjusted so that the offset of the rotor with the larger offset does not exceed ±90° to avoid step loss. The angle of the first rotor 22 is measured by the first angle sensor 13. The induced voltage angle estimation unit 31 obtains the electrical angle of the first rotor by dividing the value measured by the first angle sensor 13 by half of the number of poles p1 of the first rotor. Similarly, the induced voltage angle estimation unit 31 obtains the electrical angle of the second rotor by dividing the value measured by the second angle sensor 14 by the number of poles p2 of the second rotor.

[0109] This will be explained in detail using Figure 12. The power converter 4 receives the electrical angle of the induced voltage of the first rotor 22 and the electrical angle of the induced voltage of the second rotor 23 as input, and calculates offset 1 and offset 2 with respect to the electrical angle of the voltage, respectively. Offset 1 and offset 2 are compared, and the value with the larger absolute value is determined as the final offset, and the electrical angle θ of the voltage of the power that drives the synchronous machine 2 is determined based on the final offset. V This is adjusted to prevent the synchronous machine 2 from losing step. This adjustment is performed, for example, in the load regulator 411 of the calculation function unit 41 inside the power converter 4, as shown in Figure 12, if the final offset is within a predetermined tolerance range (for example, the range of [-30°, +30°]), the adjustment value of the frequency command is zero. When the final offset exceeds the tolerance range, the adjustment is made by adding a value proportional to the final offset as an adjustment value to the frequency command so that the absolute value of the final offset becomes smaller.

[0110] The voltage command for the power is determined, for example, from a preset setting function based on the power frequency command.

[0111] (Effects and Benefits) As described above, in the variable speed power device 1 according to this embodiment, the power converter 4 performs V / f control based on the larger of the absolute values ​​of the voltage offset from the electrical angle of the first rotor 22 and the electrical angle of the second rotor 23, and adjusts the frequency of the power that drives the synchronous machine 2.

[0112] Unlike, for example, the variable speed power unit 1 according to this embodiment, which performs vector control as described in the first embodiment, does not require estimation of the angle of the combined magnetic flux from the first rotor and the second rotor, thus eliminating the need to perform processing in the flux linkage estimation unit 310. In applications where a gradual response is required, adopting the variable speed power unit 1 according to this embodiment makes it possible to suppress step loss with simpler processing. A feature of this embodiment is that the drive power, particularly the frequency, is adjusted based on the electrical angle of the induced voltage of the rotor closer to step loss among the first rotor 22 and the second rotor 23. In other embodiments, there may be a vector controller that uses the electrical angle of the induced voltage of the first rotor 22 as a reference and a vector controller that uses the electrical angle of the induced voltage of the second rotor 23 as a reference, and vector control may be performed using the vector controller of the rotor closer to step loss.

[0113] <Ninth Embodiment> Next, a variable-speed power unit 1 according to the ninth embodiment of this disclosure will be described. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0114] Figure 13 is a diagram showing the functional configuration of a variable speed power device according to the ninth embodiment of this disclosure. As shown in Figure 13, the control device 3 according to this embodiment has an induced voltage vector estimation unit 312.

[0115] The induced voltage vector estimation unit 312 estimates the angle of the induced voltage vector based on the voltage and current of the power line 11 driving the synchronous machine 2, and outputs the electrical angle of the induced voltage. The calculated electrical angle of the induced voltage is output to the power converter 4.

[0116] Figure 14 shows the functional configuration of the power converter according to the ninth embodiment. As shown in Figure 14, the power converter 4 according to this embodiment has a load regulator 411 in addition to a vector controller in the calculation function unit 41. The specific configuration of the load regulator 411 is the same as in the eighth embodiment.

[0117] The calculation function unit 41 calculates the electrical angle θ of the voltage in the load regulator 411. V Then, the second angle sensor 14, which is installed on the load shaft (in this embodiment, the second rotor 23), adjusts the power frequency based on the offset of the angle (second angle) measured by the sensor, thereby preventing the load shaft from losing synchronism.

[0118] (Operation of the control device) Next, the operation of the control device 3 according to this embodiment will be described in detail. The induced voltage vector estimation unit 312 estimates the induced voltage vector generated in the armature from the voltage vector, the current vector, and the impedance of the armature. The current vector and the voltage vector are determined by the electrical angle θ of the second rotor. e These are then calculated using equations (12) and (13), respectively.

[0119]

number

[0120]

number

[0121] Here, i is the AC phase current supplied to synchronous machine 2, and v is the AC phase voltage supplied to synchronous machine 2. The symbol "·" indicates a complex number. j is the imaginary unit.

[0122] Synchronous machine 2 is generally driven by three-phase AC. When there are differences between the three phases, the voltage vector and current vector are calculated using equations (14) and (15), respectively. The three phases are U-phase, V-phase, and W-phase, and the electrical angles of the V-phase and W-phase are obtained by subtracting 120° (2π / 3) and 240° (4π / 3), respectively, from the electrical angle of the U-phase at the same time. Considering such differences between phases is also included within the scope of this embodiment.

[0123]

number

[0124]

number

[0125] Alternatively, it can be easily calculated from the instantaneous value using the following equations (16) and (17).

[0126]

number

[0127]

number

[0128] If we represent the armature impedance as Z^· (Z with a "·" above it; the same applies hereafter), the induced voltage vector E^· can be calculated from the voltage vector V^· and the current vector I^· using the following equation (18).

[0129]

number

[0130] Here, impedance is calculated from resistance R and inductance L using the following equation (19). The values ​​of R and L are predetermined. ω e For example, this is the angular frequency of the adjusted frequency command. In addition, ω e Alternatively, the electrical angular frequency of the first rotor 22, the electrical angular frequency of the second rotor 23, and the electrical angular frequency of the induced voltage may be used.

[0131]

number

[0132] Figure 15 is a diagram showing an example of an induced voltage vector according to the eighth embodiment of this disclosure, representing a load operation state. Figure 15 shows how the angle of the induced voltage vector is offset with respect to the electrical angle of the second rotor 23 due to the influence of the first rotor 22. In Figure 15, the electrical angle of the induced voltage vector E^·, which is the sum of the induced voltage vector E1^· of the first rotor 22 and the induced voltage vector E2^· of the second rotor 23, is drawn so that it is on the real axis. δ is the angle between the voltage vector V^· and the induced voltage vector E^·, and is a value called the load angle. ε is the angle between the induced voltage E^· and the induced voltage of the second rotor 23.

[0133] Under load operation, the angle of the induced voltage E^· of a magnetic geared motor is generally not determined solely by the angle of the first rotor or solely by the angle of the second rotor. Vector control requires the angle of the induced voltage, and in the first embodiment of this application, the angle of the first rotor and the angle of the second rotor were measured to estimate the electrical angle of the induced voltage E^·. In the first embodiment, measurement of the rotor angle was necessary. In contrast, in this embodiment, the electrical angle of the induced voltage E^· is determined from the measured values ​​of the voltage vector V^· and the current vector I^· based on equation (18). A feature of this embodiment is that an angle sensor is not required.

[0134] As described in the eighth embodiment, the load shaft, for example, the second rotor, loses synchronization if the offset δ+ε of the load shaft relative to the voltage vector V^· exceeds the range of ±90° (±π / 2). Vector control adjusts the power supplied to the magnetic geared motor and cannot dynamically adjust the distribution to the first rotor or the second rotor. Therefore, as shown in Figure 14, the power converter 4 adds the load regulator 411 described in the eighth embodiment to adjust the frequency command so that the offset δ+ε of the load shaft is within a predetermined allowable range, such as ±45°.

[0135] The load regulator 411 receives a frequency command and outputs an adjusted frequency command. The speed controller outputs a torque command, for example, by proportional-integral control, so that the electrical angular frequency of the load shaft matches the adjusted frequency command. The torque command here refers to the torque of a virtual rotating shaft that rotates at the angular frequency of the induced voltage. The vector controller adjusts the frequency command and voltage command based on the electrical angle of the induced voltage to quickly set the magnetic geared motor. In the settled state, all the power supplied by the power converter 4, excluding losses, is consumed by the load shaft.

[0136] (Effects and Benefits) As described above, in the variable speed power device 1 according to this embodiment, the induced voltage vector estimation unit 312 estimates the induced voltage vector based on the voltage and current driving the synchronous machine 2 and outputs the electrical angle of the induced voltage.

[0137] This allows vector control to be implemented in the variable speed power unit 1 even without a rotor angle gauge.

[0138] <Tenth Embodiment> Next, a variable speed power device 1 according to the tenth embodiment of this disclosure will be described. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0139] Figure 16 is a diagram showing the functional configuration of a variable speed power device according to the tenth embodiment of this disclosure. As shown in Figure 16, the induced voltage vector estimation unit 312 according to this embodiment estimates the load angle δ based on the voltage, current, and electrical angular frequency of the power driving the synchronous machine 2. In this embodiment, the second angle sensor 14 of the second rotor 23 is not required.

[0140] (Operation of the control device and power converter) In the ninth embodiment, a second angle sensor 14 is required to measure the angle of the second rotor 23, which incurs costs for the sensor and wiring. On the other hand, this embodiment eliminates the cost of angle measuring sensors and wiring. Specifically, in this embodiment, the current vector and induced voltage vector are calculated based on the voltage vector.

[0141] Figure 17 is a diagram illustrating an example of the operation of a power converter according to the tenth embodiment of this disclosure. The power converter 4 outputs a voltage that matches the voltage angle command located inside the power converter 4. Therefore, the electrical angle of the voltage is equal to the voltage angle command θ. V We will use it as is. Assuming that the voltage amplitude follows the command value |V| inside the power converter 4, the real axis is θ v In this case, the voltage vector is expressed by the following equation (21).

[0142]

number

[0143] The electrical angle θ of the voltage vector V Using as the reference point, the current vector can be expressed as shown in equation (22).

[0144]

number

[0145] Figure 18 shows an example of a load angle according to the tenth embodiment of this disclosure. The induced voltage vector E· can be calculated from the voltage vector V· and the current vector I· using equation (18) above, similar to the eighth embodiment. The impedance in equation (19) is calculated using the electrical angular frequency ω of the voltage V. eIn this embodiment, since the voltage vector is used as the reference, the electrical angle of the induced voltage vector is the load angle δ, as shown in Figure 18. Therefore, as shown in Figure 17, the power converter 4 does not calculate the load angle δ in the calculation function unit 41, but rather uses the electrical angle (load angle δ) of the induced voltage vector input from the control device 3 to calculate the corrected value of the frequency command.

[0146] (Effects and Benefits) As described above, in the variable speed power device 1 according to this embodiment, the induced voltage vector estimation unit 312 estimates the load angle δ based on the voltage, current, and electrical angular frequency of the power driving the synchronous machine 2.

[0147] In this way, the variable-speed power unit 1 can eliminate the need to measure the first angle of the first rotor 22. This reduces the cost of the first angle sensor 13 and wiring.

[0148] <Embodiment 11> Next, a variable speed power device 1 according to the eleventh embodiment of this disclosure will be described. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0149] Figure 19 is a diagram showing the functional configuration of a variable speed power device according to the 11th embodiment of this disclosure. As shown in Figure 19, the control device 3 according to this embodiment further includes an impedance changing unit 33. While Figure 19 illustrates a configuration of the tenth embodiment (Figure 16) with the impedance changing unit 33 added, the embodiment is not limited to this. In other embodiments, the configuration of the ninth embodiment (Figure 13) may also be modified with the impedance changing unit 33 added.

[0150] The impedance changing unit 33 uses the active power, reactive power, and the electrical angular frequency ω of the voltage of the synchronous machine 2. eBased on this, the value of the armature impedance is changed. The electrical angular frequency is not limited to voltage. For example, the electrical angular frequencies of current, the first rotor, and the second rotor coincide with the electrical angular frequency of voltage in the set state. The electrical angular frequency of voltage may be substituted with these electrical angular frequencies.

[0151] Furthermore, the induced voltage vector estimation unit 312 according to this embodiment estimates the induced voltage vector based on the current driving the synchronous machine 2, the electrical angle of the voltage, and the value of the modified impedance.

[0152] (Operation of the control device) The armature impedance is used to estimate the induced voltage vector. This impedance is not a constant value, but fluctuates depending on the motion of the first rotor 22 and the second rotor 23, and the ease with which magnetic flux passes through the magnetic circuit inside the synchronous machine 2 due to magnetic saturation (permeance). In this embodiment, the value of the impedance is changed according to the active power, reactive power, and rotational speed of the synchronous machine 2.

[0153] The initial impedance value is set through prior testing. The electrical angular frequency of voltage V may be substituted with the electrical angular frequency of the second rotor.

[0154] Active power P is the power that drives the load, and is calculated from the voltage vector V· and the current vector I· using the following equation (23).

[0155]

number

[0156] Here, the symbol * represents the conjugate complex number, and Re represents the real part of the complex number.

[0157] Furthermore, reactive power Q is power that is not used to drive the load but is mainly stored as magnetic energy, and is calculated using the following equation (24).

[0158]

number

[0159] In equation (24), Im represents the imaginary part of the complex number.

[0160] (Effects and Benefits) As described above, the variable speed power unit 1 according to this embodiment further includes an impedance changing unit 33 that changes the impedance value based on the active power, reactive power, and electrical angular frequency of the voltage of the synchronous machine 2. In addition, the induced voltage vector estimation unit 312 estimates the induced voltage vector based on the current driving the synchronous machine 2, the electrical angle of the voltage, and the changed impedance value.

[0161] In this way, the variable-speed power unit 1 can reflect the change in impedance in the calculation of the induced voltage vector, thereby enabling a more accurate estimation of the induced voltage vector.

[0162] <Twelfth Embodiment> Next, a variable-speed power unit 1 according to the twelfth embodiment of this disclosure will be described. Components common to the embodiments described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0163] Figure 20 is a diagram showing the functional configuration of a variable speed power device according to the twelfth embodiment of the present disclosure. The control device 3 according to this embodiment is an improvement over the control device 3 according to the ninth embodiment. Specifically, as shown in Figure 20, the control device 3 according to this embodiment further includes a phase compensation unit 314 in addition to the induced voltage vector estimation unit 312.

[0164] The phase compensation unit 314 (phase compensator) generates a phase compensation signal that phase-compensates for the inertia of the first rotor 22 based on the electrical angle of the second rotor 23.

[0165] Furthermore, the induced voltage vector estimation unit 312 according to this embodiment estimates the electrical angle of the induced voltage in addition to the electrical angle θ of the first rotor 22, based on the voltage, current, and electrical angular frequency of the power driving the synchronous machine 2.e1 We estimate this.

[0166] (Operation of the control device) The magnetic geared motor has a first rotor 22 and a second rotor 23. The armature is common to both rotors. Therefore, even if power is applied to the second rotor 23 from the armature, for example, some of that power excites the motion of the first rotor 22, causing the first rotor 22 to vibrate. The aim of this embodiment is to suppress the vibration of the first rotor 22 by applying a damping force to it.

[0167] The induced voltage vector E1· of the first rotor 22 coincides with the voltage vector V· in the settled state. However, in the transient state, the first rotor 22 also uses power to accelerate or decelerate its own inertia, so the two do not coincide. Therefore, the induced voltage vector E1· of the first rotor 22 is estimated from equation (25).

[0168]

number

[0169] The induced voltage vector E2^· of the second rotor 23 has magnitude A E2 Assume that this has been tested and obtained in advance. The angle θ of the voltage vector V , angle θ of the current vector I , the electrical angle θ of the second rotor 23 e2 Using the measured values, the induced voltage vector of the first rotor 22 can be expressed by equation (26).

[0170]

number

[0171] Therefore, the angle of the induced voltage vector, i.e., the electrical angle θ of the first rotor 22, is... e1 This is obtained by equation (27).

[0172]

number

[0173] The phase compensation unit 314 controls the electrical angle θ of the first rotor 22. e1 Based on this, the compensation torque is calculated and output. Compensation Torque T D This is generated, for example, in proportion to the speed of the first rotor 22, as shown in equation (28). kD and τD are adjustment constants. s is the Laplace operator.

[0174]

number

[0175] (Operation of the power converter) Figure 21 is a diagram showing the functional configuration of a power converter according to the twelfth embodiment of this disclosure. As shown in Figure 21, the power converter 4 receives the compensated torque as input, and the calculation function unit 41 subtracts the torque compensation signal from the torque command output by the speed controller to calculate the compensated torque command. The vector controller adjusts the power frequency and voltage according to the compensated torque command.

[0176] (Effects and Benefits) As described above, in the variable speed power device 1 according to this embodiment, the induced voltage angle estimation unit 31 estimates the electrical angle of the induced voltage in addition to the electrical angle θ of the first rotor 22 based on the voltage, current, and electrical angular frequency of the power driving the synchronous machine 2. e1 We estimate this.

[0177] In this way, the variable-speed power unit 1 can suppress the synchronous machine 2 from losing synchronism while damping vibrations of the first rotor 22.

[0178] <Hardware Configuration> Figure 22 shows an example of the hardware configuration of the equipment constituting a variable speed power device according to at least one embodiment of the present disclosure. The following describes an example of the hardware configuration of the control device 3, power converter 4, and second power converter 8 that constitute the variable speed power unit 1, with reference to Figure 22.

[0179] As shown in Figure 22, the computer 1000 includes a processor 1001, main memory 1002, auxiliary memory 1003, and interface 1004.

[0180] The control device 3, power converter 4, and second power converter 8 described in each of the above embodiments are each implemented in the computer 1000. The operation of each of the above-described processing units is stored in the auxiliary storage device 1003 in the form of a program. The processor 1001 reads the program from the auxiliary storage device 1003, expands it into the main memory 1002, and executes the above processing according to the program. The processor 1001 also allocates memory areas in the main memory 1002 to be used for various processing according to the program. The processor 1001 also allocates memory areas in the auxiliary storage device 1003 to store data being processed according to the program.

[0181] The program may be for implementing a part of the functions that the computer 1000 is to perform. For example, the program may perform functions in combination with other programs already stored in the auxiliary storage device 1003, or in combination with other programs implemented in other devices. In other embodiments, the computer 1000 may be equipped with a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions implemented by the processor 1001 may be implemented by the integrated circuit.

[0182] Examples of auxiliary storage devices 1003 include HDDs (Hard Disk Drives), SSDs (Solid State Drives), magnetic disks, magneto-optical disks, CD-ROMs (Compact Disc Read Only Memory), DVD-ROMs (Digital Versatile Disc Read Only Memory), and semiconductor memory. The auxiliary storage device 1003 may be an internal media directly connected to the bus of the computer 1000, or it may be an external storage device 1010 connected to the computer 1000 via an interface 1004 or a communication line. Furthermore, if this program is distributed to the computer 1000 via a communication line, the computer 1000 that receives the distribution may expand the program into the main memory 1002 and execute the above processing. In at least one embodiment, the auxiliary storage device 1003 and the external storage device 1010 are tangible storage media that are not temporary.

[0183] As described above, several embodiments of the present invention have been explained, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0184] <Note> The variable speed power device and control method described in the above-described embodiment can be understood, for example, as follows.

[0185] (1) According to a first aspect of the present disclosure, the variable speed power unit (1) comprises a synchronous machine (2) having a stator (21) on which armature windings (212) are provided to form an armature, a first rotor (22) having magnetic poles (222), and a second rotor (23) provided between the first rotor (22) and the stator (21) to drive a load, an induced voltage vector estimation unit (312) that estimates the electrical angle of an induced voltage generated in the armature based on the current and voltage driving the synchronous machine (2), and a power converter (4) that adjusts the frequency of the power driving the synchronous machine (2) based on the estimated electrical angle of the induced voltage.

[0186] (2) According to a second aspect of the present disclosure, in the variable speed power device (1) according to the first aspect, the induced voltage vector estimation unit (312) estimates the induced voltage vector based on the current and voltage driving the synchronous machine (2) and the electrical angle of the second rotor (23), determines the offset of the induced voltage vector with respect to the electrical angle of the second rotor (23), and estimates the electrical angle of the induced voltage based on the electrical angle of the second rotor (23) and the estimated offset of the induced voltage vector.

[0187] (3) According to a third aspect of the present disclosure, in a variable speed power device (1) according to a second aspect, the induced voltage vector estimation unit (312) further includes a phase compensation unit (314) that generates a phase compensation signal that phase-compensates for the offset of the induced voltage vector based on the electrical angle of the second rotor (23) and the induced voltage vector, and further estimates the electrical angle of the induced voltage based on the generated phase compensation signal.

[0188] (4) According to a fourth aspect of the present disclosure, in a variable speed power device (1) according to the first aspect, the induced voltage vector estimation unit (312) estimates an induced voltage vector based on the current and voltage driving the synchronous machine (2) and the electrical angular frequency of the voltage, and estimates the angle of the induced voltage vector with respect to the voltage vector as the electrical angle of the induced voltage.

[0189] (5) According to a fifth aspect of the present disclosure, a variable speed power unit (1) according to any one of the second to fourth aspects further comprises an impedance changing unit (33) that changes the value of the armature impedance based on the active power and reactive power of a synchronous machine (2) and the electrical angular frequency of the voltage, and an induced voltage vector estimation unit (312) that further estimates the induced voltage vector based on the updated impedance value.

[0190] (6) According to a sixth aspect of the present disclosure, a control method for a synchronous machine (2) having a stator (21) on which armature windings (212) are provided to form an armature, a first rotor (22) having magnetic poles (222), and a second rotor (23) provided between the first rotor (22) and the stator (21) to drive a load, comprises the steps of: estimating the electrical angle of an induced voltage generated in the armature based on the current and voltage driving the synchronous machine (2); and adjusting the frequency of the power driving the synchronous machine (2) based on the estimated electrical angle of the induced voltage. [Explanation of Symbols]

[0191] 1. Variable Speed ​​Power Unit 11 Power lines 13. First Angle Sensor 14. Second angle sensor 2 Synchronous Machine 21 Stator 211 Teeth 212 Armature Winding 213 Magnet 22 First Rotor 221 Core 222 Magnetic Pole 223 Relief Portion 224 Brake Winding 23 Second Rotor 231 Magnetic Pole 232 Non-Magnetic Portion 24 Output Shaft 3 Control Device 31 Induced Voltage Angle Estimation Unit 310 Linked Flux Estimation Unit 311 Calculation Unit 312 Induced Voltage Vector Estimation Unit 314 Phase Compensation Unit 315 Load Angle Estimation Unit 32 First Angle Estimation Unit 33 Impedance Change Unit 7]4 Power Converter 41 Arithmetic Function Unit 5 First Motor 51 Rotor (Third Rotor) 52 Electric Wire 6 Reducer 61 First Gear 62 Second Gear 63 Joint 64 Shaft 7 Second Motor 71 Rotor (Fourth Rotor) 8 Second Power Converter[[ID=z2]] 1000 Computer 1001 Processor 1002 Main Memory Device 1u03 Auxiliary Memory Device 1004 Interface 1010 External Memory Device

Claims

1. A synchronous magnetic geared motor comprising: a stator having armature windings to form an armature; a first rotor having a plurality of first magnetic poles arranged circumferentially on its outer circumference; and a second rotor provided between the first rotor and the stator, having second magnetic poles and non-magnetic parts arranged alternately circumferentially, which drives a load by rotating when the rotational power of the first rotor is transmitted magnetically between the first and second magnetic poles. An induced voltage vector estimation unit estimates the electrical angle of the induced voltage generated in the armature based on the current and voltage driving the synchronous machine, A power converter that adjusts the frequency of the power driving the synchronous machine based on the estimated electrical angle of the induced voltage, Equipped with, The induced voltage vector estimation unit is, An induced voltage vector is estimated based on the current and voltage driving the synchronous machine and the electrical angle of the second rotor, and the offset of the induced voltage vector with respect to the electrical angle of the second rotor is determined. The electrical angle of the induced voltage is estimated based on the electrical angle of the second rotor and the offset of the induced voltage vector. Variable speed power unit.

2. The induced voltage vector estimation unit further includes a phase compensation unit that generates a phase compensation signal that phase-compensates for the offset of the induced voltage vector based on the electrical angle of the second rotor and the induced voltage vector. Based on the generated phase compensation signal, the electrical angle of the induced voltage is estimated. The variable speed power device according to claim 1.

3. The induced voltage vector estimation unit is, The induced voltage vector is estimated based on the current and voltage driving the synchronous machine and the electrical angular frequency of the voltage. The angle of the induced voltage vector with respect to the voltage vector is estimated as the electrical angle of the induced voltage. The variable speed power device according to claim 1.

4. A synchronous magnetic geared motor comprising: a stator having armature windings to form an armature; a first rotor having a plurality of first magnetic poles arranged circumferentially on its outer circumference; and a second rotor provided between the first rotor and the stator, having second magnetic poles and non-magnetic parts arranged alternately circumferentially, which drives a load by rotating when the rotational power of the first rotor is transmitted magnetically between the first magnetic poles and the second magnetic poles, An induced voltage vector estimation unit estimates the electrical angle of the induced voltage generated in the armature based on the current and voltage driving the synchronous machine, A power converter that adjusts the frequency of the power driving the synchronous machine based on the estimated electrical angle of the induced voltage, Equipped with, The induced voltage vector estimation unit is, The induced voltage vector is estimated based on the current and voltage driving the synchronous machine and the electrical angular frequency of the voltage. The angle of the induced voltage vector with respect to the voltage vector is estimated as the electrical angle of the induced voltage. Variable speed power unit.

5. The system further comprises an impedance changing unit that changes the value of the armature impedance based on the active power, reactive power, and electrical angular frequency of the voltage of the synchronous machine, The induced voltage vector estimation unit estimates the induced voltage vector based on the updated impedance value. A variable speed power device according to any one of claims 1 to 4.

6. A control method for a synchronous magnetic geared motor comprising: a stator having armature windings to form an armature; a first rotor having a plurality of first magnetic poles arranged circumferentially on its outer circumference; and a second rotor provided between the first rotor and the stator, having second magnetic poles and non-magnetic parts arranged alternately circumferentially, which drives a load by rotating when the rotational power of the first rotor is transmitted magnetically between the first magnetic poles and the second magnetic poles, wherein the second rotor is provided between the first rotor and the stator, and has second magnetic poles and non-magnetic parts arranged alternately on its outer circumference, and the rotation is transmitted magnetically between the first magnetic poles and the second magnetic poles, the control method for a synchronous magnetic geared motor, The steps include: estimating the electrical angle of the induced voltage generated in the armature based on the current and voltage driving the synchronous machine; The steps include adjusting the frequency of the power driving the synchronous machine based on the estimated electrical angle of the induced voltage, It has, The step of estimating the electrical angle of the induced voltage is: An induced voltage vector is estimated based on the current and voltage driving the synchronous machine and the electrical angle of the second rotor, and the offset of the induced voltage vector with respect to the electrical angle of the second rotor is determined. The electrical angle of the induced voltage is estimated based on the electrical angle of the second rotor and the offset of the induced voltage vector. Control method.

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