Drive device and control method for drive device

Abstract

The drive device includes: a synchronous machine having a high-speed rotor and a low-speed rotor; and a control device for controlling the operation of the synchronous machine, the control device being provided with: a torque command value acquisition unit for acquiring a torque command value for adjusting the torque output by the synchronous machine; a speed measurement unit that measures the rotational speeds of the high-speed rotor and the low-speed rotor; and a torque command value correction unit that calculates a torque correction amount for damping a change rate of a magnetic displacement angle of the high-speed rotor and the low-speed rotor so as to be proportional to a speed difference between the high-speed rotor and the low-speed rotor, and corrects the torque command value.

Description

Technical Field

[0001] The present invention relates to a drive device and a control method for the drive device.

[0002] This application claims the priority based on Japanese Patent Application No. 2022-212334 filed in Japan on December 28, 2022, and incorporates its content herein. Background Art

[0003] A magnetic gear motor includes a high-speed rotor, a low-speed rotor, and a stator disposed on concentric shafts. By supplying alternating current to the coil of the stator, the high-speed rotor rotates, and by the rotation of the high-speed rotor, the low-speed rotor rotates at a predetermined reduction ratio.

[0004] In a magnetic gear motor, if the magnetic displacement angle between the high-speed rotor and the low-speed rotor exceeds 90 degrees statically, out-of-step occurs. Therefore, if the output of the magnetic gear motor or the load (or prime mover) connected to the magnetic gear motor is adjusted so that the displacement angle does not exceed 90 degrees, out-of-step is less likely to occur.

[0005] As a method for suppressing out-of-step, for example, in Patent Document 1, it is described that in a magnetic coupling that transmits the rotational output of a prime mover (turbine) to a generator, when the displacement angle between the drive-side rotating shaft on the prime mover side and the driven-side rotating shaft on the generator side exceeds the allowable range, the rotational output of the prime mover is reduced. And it is described that considering the reduction of the magnetic force of the magnet used for the magnetic coupling due to the rise in temperature, the allowable range of the displacement angle is changed according to the temperature around the magnetic coupling.

[0006] Moreover, out-of-step occurs, for example, when the magnetic gear motor is suddenly overloaded. Therefore, if the displacement angle is less likely to change with respect to the load change, out-of-step can be suppressed. To make the displacement angle less likely to change, for example, increasing the rotor torsional damping is sufficient. If the motor torque is changed in proportion to the change speed of the displacement angle (= number of pole pairs of the high-speed rotor × speed of the high-speed rotor - number of pole pieces × speed of the low-speed rotor), apparently, the rotor torsional damping increases. That is, by feeding back the rotational speeds of the two rotors and performing torque control of the motor, the rotor torsional damping can be increased.

[0007] For example, in Patent Document 2, a method is described in which the rotational speeds of the high-speed rotor and the low-speed rotor are estimated by using a linear observer without providing a speed sensor, and the rotational speeds of the two rotors are fed back.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-125991

[0011] Patent Document 2: Specification of Chinese Patent Application Publication No. 110880893 Summary of the Invention

[0012] Technical Problem to be Solved by the Invention

[0013] However, the rate of change of temperature is much slower (more than 1 to 2 orders of magnitude) compared to the rate of change of the displacement angle. Therefore, in the method described in Patent Document 1, for events such as sudden changes in the displacement angle due to load mutations, the improvement effect of avoiding out-of-step may become smaller.

[0014] Moreover, a linear observer is used in the method described in Patent Document 2, but the magnetic gear has non-linear characteristics. Therefore, in the method described in Patent Document 2, the performance can be guaranteed near the linearized operating point, but when the operating point of the magnetic spring changes significantly (for example, in the case of excessive load changes or out-of-step), the model becomes inaccurate. As a result, not only can't torsional damping be imparted to the rotor, but according to the design, the system may also become unstable.

[0015] An object of the present invention is to provide a drive device and a control method for the drive device that can obtain effective torsional damping of the rotor even when the operating point of the magnetic spring changes significantly, such as in the case of large load variations.

[0016] Means for Solving the Technical Problem

[0017] According to one aspect of the present invention, a drive device includes: a synchronous machine having a high-speed rotor and a low-speed rotor; and a control device for controlling the operation of the synchronous machine, wherein the control device includes: a torque command value acquisition unit that acquires a torque command value for adjusting the torque output by the synchronous machine; a speed measurement unit that measures the rotational speeds of the high-speed rotor and the low-speed rotor; and a torque command value correction unit that calculates a torque correction amount for damping the change speed of the magnetic displacement angle of the high-speed rotor and the low-speed rotor in proportion to the speed difference between the high-speed rotor and the low-speed rotor, and corrects the torque command value.

[0018] In a control method for a drive device according to one aspect of the present invention, the drive device includes: a synchronous machine having a high-speed rotor and a low-speed rotor; and a control device for controlling the operation of the synchronous machine, and the control method for the drive device includes the following steps: acquiring a torque command value for adjusting the torque output by the synchronous machine; measuring the rotational speeds of the high-speed rotor and the low-speed rotor; and calculating a torque correction amount for damping the change speed of the magnetic displacement angle of the high-speed rotor and the low-speed rotor in proportion to the speed difference between the high-speed rotor and the low-speed rotor, and correcting the torque command value.

[0019] Advantages of the Invention

[0020] According to the above method, even when there is a large load change or the operating point of the magnetic spring changes significantly, effective torsional damping of the rotor can be obtained. Description of the Drawings

[0021] Figure 1 It is a schematic diagram showing the overall structure of the drive device according to the first embodiment.

[0022] Figure 2 It is a block diagram showing the functional structure of the control device according to the first embodiment.

[0023] Figure 3 It is a flowchart showing an example of the processing of the control device according to the first embodiment.

[0024] Figure 4 It is a diagram for explaining the function of the drive device according to the first embodiment.

[0025] Figure 5 It is a diagram for explaining the function of the control device according to the second embodiment.

[0026] Figure 6 It is a diagram for explaining the function of the control device according to the third embodiment.

[0027] Figure 7 It is a diagram for explaining the function of the control device according to the fourth embodiment.

[0028] Figure 8 It is a block diagram showing the functional structure of the control device according to the fifth embodiment.

[0029] Figure 9 It is the first block diagram showing the functional structure of the control device according to the sixth embodiment.

[0030] Figure 10 It is the second block diagram showing the functional structure of the control device according to the sixth embodiment.

[0031] Figure 11 It is a diagram showing an example of the variable gain according to the sixth embodiment.

[0032] Figure 12 It is a block diagram showing the functional structure of the control device according to the seventh embodiment.

[0033] Figure 13 It is a block diagram showing the functional structure of the power converter according to the eighth embodiment. Detailed Description of the Invention

[0034] <First Embodiment>

[0035] (Overall Structure of the Driving Device)

[0036] Hereinafter, with reference to Figures 1 to 4 , the driving device 1 according to the first embodiment of the present invention will be described.

[0037] Figure 1 is a schematic diagram showing the overall structure of the driving device according to the first embodiment.

[0038] As Figure 1 shown, the driving device 1 includes a synchronous machine 10, a control device 20, and a power converter 30.

[0039] The synchronous machine 10 is a magnetic gear motor. The synchronous machine 10 functions as a motor or a generator. In the present embodiment, an example in which the synchronous machine 10 is used as a motor will be described.

[0040] The synchronous machine 10 includes a stator 11, a high-speed rotor 12, and a low-speed rotor 13. The stator 11 has a cylindrical shape centered on the axis O and covers the high-speed rotor 12 and the low-speed rotor 13 from the outer peripheral side. The high-speed rotor 12 can rotate about the axis O. The low-speed rotor 13 is disposed between the stator 11 and the high-speed rotor 12 and can rotate about the axis O. When current is supplied to the coil of the stator 11 from the power converter 30, the high-speed rotor 12 rotates. And when the high-speed rotor 12 rotates, the low-speed rotor 13 rotates at a specified reduction ratio. The low-speed rotor 13 is connected to the load through a rotating shaft 15 and drives the load by rotating together with the low-speed rotor 13 through the rotating shaft 15.

[0041] The control device 20 controls the operation of the synchronous machine 10. In particular, the control device 20 according to the present embodiment outputs a torque command for adjusting the torque output by the synchronous machine 10 in order to suppress the out-of-step between the high-speed rotor 12 and the low-speed rotor 13 of the synchronous machine 10.

[0042] The power converter 30 supplies current to the coil of the stator 11 of the synchronous machine 10 so that the synchronous machine 10 can output a torque corresponding to the torque command of the control device 20.

[0043] (Functional Structure of the Control Device)

[0044] Figure 2 is a schematic diagram showing the overall structure of the driving device according to the first embodiment.

[0045] As Figure 2 shown, the control device 20 includes a processor 21, a memory 22, a storage device 23, and an interface 24.

[0046] The processor 21 operates according to a prescribed program, functioning as an acquisition unit 210, a torque estimation unit 211, a displacement angle estimation unit 212, a displacement angle measurement unit 213, a determination unit 214, and an adjustment unit 215.

[0047] The acquisition unit 210 acquires measurement values from the sensors of the synchronous machine 10. In the present embodiment, the acquisition unit 210 acquires measurement values for detecting the displacement angles of the high-speed rotor 12 and the low-speed rotor 13 from the first sensor 16 provided on the rotating shaft 14 of the high-speed rotor 12 and the second sensor 17 provided on the rotating shaft 15 of the low-speed rotor 13. Further, the acquisition unit 210 acquires the current value of the power for driving the synchronous machine 10 from the ammeter 18 provided on the power line between the power converter 30 and the coils of the stator 11.

[0048] The torque estimation unit 211 estimates the torque output by the synchronous machine 10 based on the current value of the power for driving the synchronous machine 10.

[0049] The displacement angle estimation unit 212 estimates the displacement angle between the high-speed rotor 12 and the low-speed rotor 13 based on the torque estimation value.

[0050] The displacement angle measurement unit 213 estimates the displacement angle between the high-speed rotor 12 and the low-speed rotor 13 based on the measurement values of the first sensor 16 and the second sensor 17.

[0051] The determination unit 214 determines whether the difference between the displacement angle estimation value and the displacement angle measurement value exceeds a prescribed threshold.

[0052] When it is determined that the difference between the displacement angle estimation value and the displacement angle measurement value exceeds the threshold, the adjustment unit 215 outputs a torque command for increasing or decreasing the torque of the synchronous machine 10.

[0053] The memory 22 has a memory area required for the operation of the processor 21.

[0054] The storage device 23 is a so-called auxiliary storage device, and can be, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0055] The interface 24 is an interface for transmitting and receiving various information between external devices (such as the power converter 30).

[0056] In addition, a prescribed program executed by the processor 21 of the control device 20 is stored in a computer-readable recording medium. The computer-readable recording medium refers to a magnetic disk, an optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc. Further, the computer program can be transmitted to a computer via a communication line, and the program is executed by the computer that has received the transmission. Moreover, the program can also be used to implement a part of the above functions. Moreover, it can be a so-called differential file (differential program) that can implement the above functions in combination with a program already recorded in a computer system.

[0057] (Processing flow of the control device)

[0058] Figure 3 FIG. is a block diagram showing the functional configuration of the control device according to the first embodiment.

[0059] Hereinafter, with reference to Figure 3 FIG., the processing flow of the control device 20 will be described in detail.

[0060] First, the acquisition unit 210 acquires measurement values from the respective sensors of the synchronous machine 10 (step S10). Specifically, the acquisition unit 210 acquires the current current value of the synchronous machine 10 from the ammeter 18, and also acquires the measurement values of the first sensor 16 and the second sensor 17.

[0061] And, the torque estimation unit 211 calculates an estimated torque value ^τm output by the synchronous machine 10 based on the current current value (step S11).

[0062] The displacement angle estimation unit 212 assumes that the load torque is balanced with the torque output by the synchronous machine 10 (in a stable state), and calculates an estimated displacement angle value ^θe between the high-speed rotor 12 and the low-speed rotor 13 of the synchronous machine 10 based on the estimated torque value ^τm (step S12). For example, the displacement angle estimation unit 212 sets the maximum transmission torque of the synchronous machine 10 as τmax, and calculates the estimated displacement angle value ^θe by the following formula (1). This estimated displacement angle value ^θe becomes an index of a stable (or quasi-stable) load state.

[0063] [Equation 1]

[0064]

[0065] Next, the displacement angle measurement unit 213 acquires a measured displacement angle value θe between the high-speed rotor 12 and the low-speed rotor 13 of the synchronous machine 10 based on the measurement values of the first sensor 16 and the second sensor 17 (step S13).

[0066] If the load changes suddenly, the balance of the torque is disrupted, resulting in a deviation between the estimated displacement angle ^θe representing the stable displacement angle and the actual displacement angle, i.e., the measured displacement angle θe. In the present embodiment, when the degree of this deviation exceeds the threshold value δ, the torque of the synchronous machine 10 is decreased (or increased) in the direction in which the change in the displacement angle is suppressed.

[0067] Specifically, first, the determination unit 214 calculates the upper limit value and the lower limit value of the displacement angle based on the estimated displacement angle ^θe (step S14). Specifically, as shown in the following equations (2) and (3), the determination unit 214 calculates the upper limit value θe,max and the lower limit value θe,min of the displacement angle based on the estimated displacement angle ^θe and the threshold value δ.

[0068] [Equation 2]

[0069]

[0070] [Equation 3]

[0071]

[0072] The threshold value δ is a preset value, for example, 10 degrees. The value of the threshold value δ can be arbitrarily changed according to the characteristics of the drive device 1, operating conditions, etc.

[0073] Next, the determination unit 214 determines whether the measured displacement angle θe exceeds the upper limit value θe,max of the displacement angle (step S15).

[0074] When the measured displacement angle θe exceeds the upper limit value θe,max (θe > θe,max), the adjustment unit 215 outputs a torque command to decrease the torque of the synchronous machine 10 (step S16).

[0075] On the other hand, when the measured displacement angle θe does not exceed the upper limit value θe,max of the displacement angle (θe ≤ θe,max), the determination unit 214 determines whether the measured displacement angle θe is less than the lower limit value θe,min of the displacement angle (step S17).

[0076] When the measured displacement angle θe is less than the lower limit value θe,min of the displacement angle (θe < θe,min), the adjustment unit 215 outputs a torque command to increase the torque of the synchronous machine 10 (step S18).

[0077] On the other hand, when the measured displacement angle θe is not less than the lower limit value θe,min of the displacement angle, that is, when the measured displacement angle θe is within the normal range of not less than the lower limit value θe,min and not more than the upper limit value θe,max of the displacement angle, the adjustment unit 215 ends the process without changing the torque of the synchronous machine 10.

[0078] Based on the torque command input from the control device 20, the power converter 30 adjusts the current supplied to the synchronous machine 10 so that the torque output by the synchronous machine 10 increases or decreases appropriately.

[0079] During the process of driving the synchronous machine 10, the control device 20 executes a series of processes each time various measured values are measured (acquired), thereby suppressing the out-of-step of the synchronous machine 10. Figure 3

[0080] Figure 4 It is a diagram for explaining the function of the drive device according to the first embodiment.

[0081] Refer to Figure 4 , and taking the case when the load increases as an example, the processing and operation of the drive device 1 will be described.

[0082] Figure 4 The graph D10 of shows the time series of the measured values of the rotational speeds of the high-speed rotor 12 and the low-speed rotor 13 of the synchronous machine 10. In the graph D10, D101 represents the value obtained by correcting the rotational speed of the high-speed rotor 12 with the reduction ratio relative to the low-speed rotor 13, and D102 represents the rotational speed of the low-speed rotor 13.

[0083] In Figure 4 In the graph D11 of , D111 represents the time series of the measured displacement angle θe, D112 represents the time series of the estimated displacement angle ^θe, D113 represents the time series of the upper limit value θe,max of the displacement angle, and D114 represents the time series of the lower limit value θe,min of the displacement angle. In addition, although briefly described in Figure 4 , actually, the estimated displacement angle ^θe becomes different values at all times according to the current value. Similarly, the upper limit value θe,max and the lower limit value θe,min of the displacement angle also become different values at all times according to the estimated displacement angle ^θe.

[0084] In Figure 4 In the graph D12 of , D121 is the measured torque value τm of the synchronous machine 10 measured experimentally, and D122 is the time series of the torque command T output by the control device 20.

[0085] In Figure 4 In the example of the graph D11 of , at time t1, the load rises and the measured displacement angle θe becomes larger, exceeding the upper limit value θe,max of the displacement angle. Therefore, the adjustment unit 215 of the control device 20 outputs a torque command T to reduce the torque of the synchronous machine 10 at time t1.

[0086] Also, at time t2, the displacement angle measurement value θe becomes equal to or less than the displacement angle upper limit value θe,max. Then, at time t2, the adjustment unit 215 of the control device 20 outputs a torque command T to the synchronous machine 10 in such a manner as to generate a torque corresponding to the load.

[0087] Similarly, during the periods from time t3 to t4 and from time t5 to t6, the displacement angle measurement value θe also exceeds the displacement angle upper limit value θe,max. Therefore, during these periods, the adjustment unit 215 outputs a torque command T that reduces the torque of the synchronous machine 10. Thus, when the deviation between the estimated displacement angle ^θe and the measured displacement angle θe of the drive device 1 increases due to an increase in the load, the torque of the synchronous machine 10 is temporarily reduced, and the measured displacement angle θe is adjusted to approach the target value, i.e., the estimated displacement angle ^θe, following the load state. Thereby, the drive device 1 suppresses the displacement angle from exceeding the limit value (90 degrees) and falling out of step.

[0088] (Function, Effect)

[0089] As described above, the drive device 1 according to the present embodiment includes: a synchronous machine 10 having a high-speed rotor 12 and a low-speed rotor 13; and a control device 20 that controls the operation of the synchronous machine 10. The control device 20 includes: a torque estimation unit 211 that estimates a torque estimation value ^τm output by the synchronous machine 10 based on the current value of the power for driving the synchronous machine 10; a displacement angle estimation unit 212 that estimates an estimated displacement angle ^θe between the high-speed rotor 12 and the low-speed rotor 13 based on the torque estimation value ^τm; a displacement angle measurement unit 213 that measures a measured displacement angle θe between the high-speed rotor 12 and the low-speed rotor 13; a determination unit 214 that determines whether the difference between the estimated displacement angle ^θe and the measured displacement angle θe exceeds a specified threshold value δ; and an adjustment unit 215 that outputs a torque command T for increasing or decreasing the torque of the synchronous machine 10 when it is determined that the difference between the estimated displacement angle ^θe and the measured displacement angle θe exceeds the threshold value δ.

[0090] When the allowable range of the displacement angle is always fixed (for example, fixed at 80 degrees, which is 10 degrees closer to the front than the static limit value of 90 degrees), for a sharp and large load change, it may be too late to perform torque operation and result in falling out of step. On the other hand, if the allowable range is set too small to suppress falling out of step, it is difficult to drive a large load (high-load operation). However, the drive device 1 according to the present embodiment does not fix the allowable range of the displacement angle, but dynamically changes based on the estimated displacement angle ^θe estimated at each time point, that is, based on the set value (the operating point of the motor) in the stable state (or quasi-stable state). Thereby, it is possible to balance the suppression of falling out of step of the high-speed rotor 12 and the low-speed rotor 13 and high-load operation.

[0091] Further, as described above, in Patent Document 1, the allowable range is changed according to the temperature around the magnetic coupling. Therefore, in the case of a sudden change in load, it is sometimes difficult to suppress out-of-step. In contrast, the drive device 1 according to the present embodiment changes the estimated displacement angle value ^θe used as an index according to the change in the current value of the synchronous machine 10, and determines whether the difference between it and the actual displacement angle measured value θe exceeds the threshold value δ. Thereby, the drive device 1 can quickly detect an increase in the displacement angle caused by a sudden change in load.

[0092] Moreover, in Patent Document 1, when the displacement angle exceeds the allowable range, the rotational output of the prime mover is reduced. In contrast, the drive device 1 according to the present embodiment changes the torque of the synchronous machine 10 instead of the load (or prime mover), so that the influence on the load (or prime mover) can be reduced and out-of-step can be suppressed. For example, the drive device 1 can suppress out-of-step while maintaining a high load state.

[0093] Further, in the drive device 1 according to the present embodiment, when it is determined that the displacement angle measured value θe exceeds the upper limit value θe,max obtained by adding the threshold value δ to the estimated displacement angle value ^θe, the adjustment unit 215 of the control device 20 outputs a torque command T for reducing the torque of the synchronous machine 10. When the displacement angle measured value θe is less than the lower limit value θe,min obtained by subtracting the threshold value δ from the estimated displacement angle value ^θe, a torque command T for increasing the torque of the synchronous machine 10 is output.

[0094] Thereby, the drive device 1 can make the upper limit value and the lower limit value of the displacement angle variable according to the estimated displacement angle value ^θe. Thereby, the drive device 1 does not react sensitively to changes in the displacement angle, and can accurately determine whether the torque of the synchronous machine 10 should be adjusted.

[0095] <Second Embodiment>

[0096] Next, with reference to Figure 5 , the drive device 1 according to the second embodiment of the present invention will be described. The same reference numerals are given to the constituent elements common to the first embodiment, and the detailed description thereof is omitted.

[0097] In the first embodiment, the determination unit 214 of the control device 20 sets the threshold value δ as a fixed value. In contrast, the determination unit 214 according to the present embodiment changes the threshold value δ according to the load state.

[0098] Figure 5 is a diagram for explaining the function of the control device according to the second embodiment.

[0099] Figure 5 shows a graph D20 showing an example of the displacement angle-torque characteristic and a graph D21 showing an example of the change in the threshold value δ.

[0100] As shown in Chart D21 Figure 5 The determination unit 214 according to the present embodiment changes the value of the threshold δ according to the magnitude of the estimated displacement angle ^θe through a preset function. If the displacement angle θe increases, the torque also increases. When the displacement angle θe reaches the limit value (90 degrees), the synchronous machine 10 reaches the maximum transmission torque. And if the displacement angle θe exceeds the limit value, it will lose synchronization. Also, as shown in Chart D20, compared with when the load is lighter (smaller torque), when the load is heavier (larger torque), the allowable degree of the synchronous machine 10 with respect to load changes becomes smaller. That is, the heavier the load, the more likely it is to lose synchronization due to load changes.

[0101] Therefore, as in the example of Chart D21, the closer the estimated displacement angle ^θe is to the limit value, the smaller the determination unit 214 makes the threshold δ. Thus, the drive device 1, for example, at high load ( Figure 5 operating point P2), reacts sensitively to the deviation degree of the measured displacement angle θe with respect to the estimated displacement angle ^θe, and can more reliably suppress loss of synchronization. On the other hand, the drive device 1 at low load ( Figure 5 operating point P1) suppresses reacting sensitively to the deviation degree of the measured displacement angle θe with respect to the estimated displacement angle ^θe, and can suppress unnecessary torque adjustment.

[0102] In addition, the determination unit 214 can prepare in advance a graph or table establishing the correspondence between the estimated displacement angle ^θe and the threshold δ, and determine the threshold δ with reference to this graph or table.

[0103] Thus, the drive device 1 can finely adjust the torque according to the load state, so it can more reliably suppress loss of synchronization and can improve the utilization rate of the torque of the synchronous machine 10.

[0104] <Third Embodiment>

[0105] Next, with reference to Figure 6 the drive device 1 according to the third embodiment of the present invention will be described. The same reference numerals are given to the constituent elements common to the first and second embodiments, and the detailed description thereof is omitted.

[0106] The determination unit 214 of the control device 20 according to the first embodiment determines whether the difference between the measured displacement angle θe and the estimated displacement angle ^θe at each time point exceeds the threshold δ each time the respective measured values are measured (acquired). In contrast, the determination unit 214 according to the present embodiment determines whether the difference between the moving averages of the measured displacement angle θe and the estimated displacement angle ^θe exceeds the threshold δ.

[0107] Specifically, the estimated displacement angle value ^θe at each moment estimated by the displacement angle estimation unit 212 and the measured displacement angle value θe at each moment measured by the displacement angle measurement unit 213 are recorded in the storage device 23. In Figure 3 In step S14 of Figure 3 , the determination unit 214 calculates an upper limit value and a lower limit value of the displacement angle based on the moving average of the estimated displacement angle value ^θe for the previous n seconds from the determination time point and the threshold value δ. And, in Figure 3 In step S15 of

[0108] , the determination unit 214 determines whether the moving average of the measured displacement angle value θe for the previous n seconds from the determination time point exceeds the upper limit value of the displacement angle. Similarly, in

[0109] In step S17 of

[0110] Figure 6 , the determination unit 214 determines whether the moving average of the measured displacement angle value θe for the previous n seconds from the determination moment is less than the lower limit value of the displacement angle.

[0111] Figure 6 Thus, the drive device 1 can suppress the misjudgment that the difference between the measured displacement angle value θe and the estimated displacement angle value ^θe exceeds the threshold value δ due to the influence of noise, measurement error, etc.

[0112] In addition, the determination unit 214 can set the averaging time n seconds to a fixed value or a variable value. Figure 6 As shown in the graph D31 of

[0113] , the determination unit 214 can use a preset function to make the averaging time n (seconds) during moving average variable according to the load state. For example, the closer the estimated displacement angle value ^θe is to the limit value, the shorter the determination unit 214 makes the averaging time n.

[0114] Thus, when the drive device 1 is at a low load ( Figure 6 operating point P3 of Figure 6 ), by extending the averaging time n, it can suppress misjudgment caused by the influence of noise, measurement error, etc. And when the drive device 1 is at a high load (

[0115] Figure 6 operating point P4 of

[0115] ), by shortening the averaging time n, it can suppress the delay in determination due to the influence of past data before the load change.In addition, in the present embodiment, an example in which the determination unit 214 makes a determination based on the moving average of the displacement angle measurement value θe and the displacement angle estimated value ^θe has been described, but it is not limited thereto. In other embodiments, the determination unit 214 may determine whether a state in which the difference between the displacement angle measurement value θe and the displacement angle estimated value ^θe exceeds a threshold value δ continues for a determination time n (seconds) or more. Further, the determination unit 214 may change the determination time n according to the displacement angle estimated value ^θe in the same manner as the averaging time n.

[0116] In this way, the drive device 1 can also suppress false determination caused by the influence of noise, measurement error, and the like.

[0117] <Fourth Embodiment>

[0118] Next, with reference to Figure 7 , the drive device 1 according to the fourth embodiment of the present invention will be described. The same reference numerals are given to the constituent elements common to the first to third embodiments, and the detailed description thereof is omitted.

[0119] In the second embodiment, an example in which the determination unit 214 changes the threshold value δ according to the displacement angle estimated value ^θe has been described. Further, in the third embodiment, an example in which the determination unit 214 changes the averaging time n (determination time n) according to the displacement angle estimated value ^θe has been described. In contrast, the determination unit 214 according to the present embodiment further changes at least one of the threshold value δ and the averaging time n (determination time n) based on a state quantity that affects the maximum transmission torque.

[0120] Further, the acquisition unit 210 according to the present embodiment further acquires a state quantity that affects the maximum transmission torque of the synchronous machine 10. Examples of the state quantity that affects the maximum transmission torque include the coil temperature of the stator 11, the respective clearance distances of the stator 11, the high-speed rotor 12, and the low-speed rotor 13, the operation history (load-time characteristics, etc.), the operation plan, and the like. The clearance distance may be a design value (initial value), but in consideration of changes due to deterioration over time, an estimated value or a measured value corresponding to the usage period of the synchronous machine 10 may also be used.

[0121] Figure 7 is a diagram for explaining the functions of the control device according to the fourth embodiment.

[0122] Figure 7 shows a graph D40 representing an example of the displacement angle-torque characteristic, a graph D41 representing an example of the change in the threshold value δ, and a graph D42 representing an example of the change in the averaging time n (or determination time n).

[0123] Here, an example in which the coil temperature of the stator 11 is used as the state quantity will be described. In Chart D41, D401 represents the displacement angle-torque characteristic when the coil temperature is high, and D402 represents the displacement angle-torque characteristic when the coil temperature is low. In addition, the displacement angle-torque characteristics for each type and each magnitude of the state quantity are pre-recorded in the storage device 23. As shown in Chart D40, regarding the maximum transmission torque, it is greater when the coil temperature is low than when the coil temperature is high. And when the same load is applied, the larger the maximum transmission torque, the greater the margin until out-of-step.

[0124] In view of this characteristic, for example, as Figure 7 shown in Chart D41 of, the determination unit 214 prepares a function for determining the threshold δ for each temperature range of the coil temperature. In addition, Figure 7 two functions are illustrated in, but the determination unit 214 may also prepare three or more functions. The determination unit 214 uses the function corresponding to the coil temperature acquired by the acquisition unit 210 to determine the threshold δ. These functions are set such that even when the displacement angle is the same (for example, A1), the threshold δ is larger when the coil temperature is low (operating point P7) than when the coil temperature is high (operating point P5).

[0125] Thereby, the determination unit 214 can appropriately adjust the threshold δ based on the magnitude of the maximum transmission torque corresponding to the state quantity and the displacement angle estimated value ^θe.

[0126] In addition, the determination unit 214 may prepare a graph or table that establishes a correspondence between the state quantity (coil temperature), the displacement angle estimated value ^θe, and the threshold δ in advance, and refer to this graph or table to determine the threshold δ.

[0127] Moreover, the determination unit 214 may also make a determination based on the moving average of the displacement angle measured value θe and the displacement angle estimated value ^θe in the same manner as in the third embodiment. And it may also be determined whether the difference between the displacement angle measured value θe and the displacement angle estimated value ^θe exceeds the determination time n. At this time, the determination unit 214 may make the averaging time n or the determination time n variable according to the state quantity.

[0128] As described above, when the same load is applied, the larger the maximum transmission torque, the greater the margin until out-of-step. In view of this characteristic, as Figure 7 shown in Chart D42 of, the determination unit 214 prepares a function for determining the averaging time n (or the determination time n) for each temperature range of the coil temperature. In addition, Figure 7Two functions are illustrated, but the determination unit 214 may also prepare three or more functions. The determination unit 214 uses the function corresponding to the coil temperature acquired by the acquisition unit 210 to determine the averaging time n (or determination time n). These functions are set such that even when the displacement angle is the same (for example, A1), the averaging time n (or determination time n) is longer at a low temperature (operating point P7) than at a high temperature (operating point P5) of the coil temperature.

[0129] Thus, the determination unit 214 can appropriately adjust the averaging time n (or determination time n) based on the magnitude of the maximum transmission torque corresponding to the state quantity and the estimated displacement angle ^θe.

[0130] In addition, the determination unit 214 may prepare in advance a graph or table that establishes a correspondence between the state quantity (coil temperature), the estimated displacement angle ^θe, and the averaging time n (or determination time n), and refer to this graph or table to determine the averaging time n (or determination time n).

[0131] In addition, the determination unit 214 may make both the threshold value δ and the averaging time n (or determination time n) variable according to the state quantity, or may make only either one of them variable.

[0132] In this way, in addition to the load state, the drive device 1 finely adjusts the torque according to the state quantity of the synchronous machine 10, so that out-of-step can be more reliably suppressed, and the utilization rate of the torque of the synchronous machine 10 can be improved.

[0133] <Fifth Embodiment>

[0134] Next, with reference to Figure 8 , the drive device 1 according to the fifth embodiment of the present invention will be described. The same reference numerals are given to the constituent elements common to the first to fourth embodiments, and detailed descriptions thereof are omitted. In addition, in the drive device 1 according to the present embodiment, the control device 20 performs the following control: for a load change, the change in the displacement angles of the high-speed rotor 12 and the low-speed rotor 13 is suppressed.

[0135] (Functional Structure of Control Device)

[0136] Figure 8 is a block diagram showing the functional structure of the control device according to the fifth embodiment.

[0137] As Figure 8 shown, the processor 21 of the control device 20 according to the present embodiment functions as a torque command value acquisition unit 216, a speed measurement unit 217, and a torque command value correction unit 218 by operating according to a prescribed program.

[0138] The torque command value acquisition unit 216 acquires the torque command value for adjusting the torque output by the adjustment synchronous machine 10. The torque command value is a value generated by an existing torque control mechanism of the control device 20 and based on the state of the load connected to the synchronous machine 10 and the like.

[0139] The speed measurement unit 217 measures the rotational speeds of the high-speed rotor 12 and the low-speed rotor 13 through the first sensor 16 and the second sensor 17. Additionally, in the present embodiment, the speed measurement unit 217 measures the angular velocities [rad / s] of the two rotors respectively.

[0140] The torque command value correction unit 218 calculates a torque correction amount for damping the magnetic displacement angles of the high-speed rotor 12 and the low-speed rotor 13 in a manner proportional to the speed difference between the high-speed rotor 12 and the low-speed rotor 13, and corrects the torque command value.

[0141] (Regarding the correction process of the torque command value)

[0142] Next, referring to Figure 8 , the detailed content of the correction process of the torque command value based on the control device 20 will be described. If the angular velocity of the high-speed rotor 12 is set as ωHSR, the angular velocity of the low-speed rotor 13 is set as ωPPR, and the gear ratio of the two rotors is set as Gr, then during the synchronization of the high-speed rotor 12 and the low-speed rotor 13, the relationship of Equation (4) holds.

[0143] [Equation 4]

[0144]

[0145] Therefore, when the high-speed rotor 12 and the low-speed rotor 13 are offset, if the torque obtained from Equation (5) is output from the synchronous machine 10, the same effect as an increase in the rotor torsional damping can be obtained. Additionally, K is a gain that determines the magnitude of the rotor torsional damping of the load.

[0146] [Equation 5]

[0147]

[0148] Specifically, the torque command value correction unit 218 of the control device 20 first calculates the speed difference Δω between the value obtained by multiplying the measured angular velocity ωPPR of the low-speed rotor 13 by the gear ratio Gr of the high-speed rotor 12 and the low-speed rotor 13 and the measured angular velocity ωHSR of the high-speed rotor 12.

[0149] Next, the torque command value correction unit 218 calculates a torque correction amount by multiplying the speed difference Δω between the two rotors by a gain K. For example, when the load increases and the angular velocity of the low-speed rotor 13 decreases, the torque command value correction unit 218 calculates a torque correction amount that reduces the torque output by the synchronous machine 10. Thereby, it is possible to suppress the relative speed difference (the change speed of the displacement angle) between the high-speed rotor 12 and the low-speed rotor 13 from becoming large, and thus it is possible to suppress the occurrence of out-of-step.

[0150] In addition, in the present embodiment, the value of the gain K is a fixed value (for example, "5.0") preset according to the characteristics of the synchronous machine 10, operating conditions, etc. The larger the value of the gain K, the greater the torsional damping of the rotor can be made.

[0151] And the torque command value correction unit 218 outputs the corrected torque command value to the power converter 30, and the corrected torque command value is the sum value of the calculated torque correction amount and the torque command value acquired by the torque command value acquisition unit 216.

[0152] (Function, effect)

[0153] As described above, in the drive device 1 according to the present embodiment, the control device 20 includes: a torque command value acquisition unit 216 that acquires a torque command value for adjusting the torque output by the synchronous machine 10; a speed measurement unit 217 that measures the angular velocities of the high-speed rotor 12 and the low-speed rotor 13; and a torque command value correction unit 218 that calculates a torque correction amount for damping the change speed of the magnetic displacement angle of the high-speed rotor 12 and the low-speed rotor 13 in proportion to the speed difference between the high-speed rotor 12 and the low-speed rotor 13, and corrects the torque command value.

[0154] Thereby, the drive device 1 can apply rotor torsional damping to the magnetic torsion of the high-speed rotor 12 and the low-speed rotor 13 by adjusting the torque output by the synchronous machine 10. As a result, the drive device 1 can make the displacement angles of the high-speed rotor 12 and the low-speed rotor 13 less likely to change, thereby suppressing the occurrence of out-of-step.

[0155] And, in order to effectively impart torsional damping to the rotor, it is necessary to accurately measure the phase (timing) of the rotational speed change. For example, in the method described in the above-mentioned Patent Document 2, if a large load change occurs or the like, a large deviation occurs from the linearized operating point (equilibrium point), it is difficult to correctly estimate the rotational speed. For example, when there is an error in the rotational speed estimation and the phase is extremely shifted by 180 degrees, negative damping occurs and the torsional vibration of the rotor is enhanced.

[0156] In contrast, the drive device 1 according to the present embodiment does not rely on estimating the rotational speeds (angular velocities) of the high-speed rotor 12 and the low-speed rotor 13, but directly measures them through the first sensor 16 and the second sensor 17. Therefore, even when a large load change occurs, the accurate rotational speed can be measured. Thus, the drive device 1 can obtain an appropriate rotor torsional damping corresponding to the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0157] Moreover, in the method described in the above Patent Document 1, the difference in the rotational angles of the high-speed rotor and the low-speed rotor, that is, the displacement angle, is monitored. When it exceeds a threshold value, that is, when a sign of out-of-step is detected, the load is adjusted to suppress out-of-step. At this time, if the threshold value is small, out-of-step may easily occur when a load change occurs under a high load. And if the threshold value is large, the load adjustment occurs excessively under a low load, which may reduce the motor efficiency.

[0158] In contrast, the drive device 1 according to the present embodiment corrects the torque command value (imparts rotor torsional damping) according to the speed difference between the high-speed rotor 12 and the low-speed rotor 13 to suppress out-of-step. Therefore, during the operation of the drive device 1, it is only necessary to always operate the correction control of the torque command value. Because when the high-speed rotor 12 and the low-speed rotor 13 are synchronized (the speed difference is close to zero), Equation (6) is obtained, so the same effect as cutting off the correction control can be obtained.

[0159] [Equation 6]

[0160]

[0161] Therefore, the control device 20 according to the present embodiment can omit complicated processes such as the detection process of the sign of out-of-step and the adjustment of the threshold value.

[0162] And, in the drive device 1 according to the present embodiment, the torque command value correction unit 218 of the control device 20 multiplies the speed difference between the high-speed rotor 12 and the low-speed rotor 13 by a prescribed gain K to calculate the torque correction amount.

[0163] Thus, the drive device 1 can adjust the magnitude of the rotor torsional damping by the value of the gain K.

[0164] <Sixth Embodiment>

[0165] Next, Figures 9 to 11 the drive device 1 according to the sixth embodiment of the present invention will be described. The same reference numerals are assigned to the constituent elements common to the first to fifth embodiments, and the detailed description thereof is omitted.

[0166] Figure 9It is the first block diagram showing the functional structure of the control device according to the sixth embodiment.

[0167] As Figure 9 shown, in the control device 20 according to the present embodiment, the torque command value correction unit 218 makes the value of the gain K variable according to the load.

[0168] There is a correlation between the magnitude of the load and the magnitude of the current flowing in the stator 11 of the synchronous machine 10 (stator current value). Therefore, the torque command value correction unit 218 changes the value of the gain K according to the magnitude of the absolute value |Istator| of the stator current value acquired from the ammeter 18.

[0169] Figure 10 It is the second block diagram showing the functional structure of the control device according to the sixth embodiment.

[0170] And, as Figure 10 shown, the torque command value correction unit 218 can make the value of the gain K variable according to the absolute value |Δω| of the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0171] Figure 11 It is a diagram showing an example of the variable gain according to the sixth embodiment.

[0172] Compared with when the load is light, when the load is heavy, the allowable degree of the synchronous machine 10 for load variation becomes smaller. That is, the heavier the load, the more likely it is to occur out-of-step due to load variation. Therefore, when changing the value of the gain K according to the load, as Figure 11 shown, the larger the absolute value |Istator| of the stator current value (the heavier the load), the larger the value of the gain K that the torque command value correction unit 218 makes.

[0173] And, in the synchronous machine 10, the larger the speed difference between the two rotors, the larger the displacement angle, and it is easy to occur out-of-step due to load variation. Therefore, when changing the value of the gain K according to the speed difference, as Figure 11 shown, the larger the absolute value |Δω| of the speed difference, the larger the value of the gain K that the torque command value correction unit 218 makes.

[0174] As described above, in the drive device 1 according to the present embodiment, the torque command value correction unit 218 of the control device 20 changes the value of the gain K according to the magnitude of the load or the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0175] Thereby, even if the magnetic gear has non-linear characteristics, that is, the restoring force of the magnetic spring changes due to the operating point, the drive device 1 can effectively obtain rotor torsional damping.

[0176] For example, the greater the load, the greater the gain K that the drive device 1 can make to increase the rotor torsional damping. Therefore, even during high-load operation where out-of-step is likely to occur due to load changes, out-of-step can be effectively suppressed. On the other hand, the rotor torsional damping hinders the movement of the system. Therefore, when the load is light (the tolerance for load changes is large), the drive device 1 can suppress the performance degradation caused by the rotor torsional damping by reducing the gain K.

[0177] Also, for example, when the speed difference becomes large due to a sudden load change, the drive device 1 can effectively suppress out-of-step by increasing the gain K to make the rotor torsional damping act strongly. On the other hand, when the speed difference is small, that is, when the load is stable and the rotational speeds of the two rotors are stable, the rotor torsional damping is preferably 0. Therefore, when the speed difference is small, the drive device 1 regards the system as a stable state and can suppress the performance degradation of the synchronous machine 10 caused by the rotor torsional damping by reducing the gain K.

[0178] That is, the control device 20 adjusts the strength of the rotor torsional damping according to the state of the system, thereby being able to balance the performance and stability (less likely to occur out-of-step) of the synchronous machine 10.

[0179] In addition, in Figure 11 example, the torque command value correction unit 218 has preset a function representing the relationship between the absolute value |Istator| of the stator current value or the absolute value |Δω| of the speed difference and the value of the gain K, and determines the value of the gain K based on this function, but it is not limited to this. In other embodiments, the torque command value correction unit 218 can prepare a table establishing the correspondence between the absolute value |Istator| of the stator current value or the absolute value |Δω| of the speed difference and the value of the gain K in advance, and determine the value of the gain K by referring to this table. And the torque command value correction unit 218 can set a specific range of the absolute value |Istator| of the stator current value or the absolute value |Δω| as a dead zone (gain K = 0).

[0180] <Seventh Embodiment>

[0181] Next, with reference to Figure 12 , the drive device 1 according to the seventh embodiment of the present invention will be described. The same reference numerals are assigned to the constituent elements common to the first to sixth embodiments, and the detailed description thereof is omitted.

[0182] Figure 12 is a block diagram showing the functional structure of the control device according to the seventh embodiment.

[0183] As Figure 12 shown, in the control device 20 according to the present embodiment, the torque command value correction unit 218 has a rate limiting unit 218A.

[0184] The rate limiting unit 218A limits the rate of change of the torque correction amount calculated by the torque command value correction unit 218. In order to suppress sudden changes in torque, when the required torque correction amount exceeds a specified rate of change, the rate limiting unit 218A performs a process of gradually increasing the torque correction amount.

[0185] In addition, Figure 12 an example in which the rate limiting unit 218A is added in a configuration using the variable gain K corresponding to the speed difference in the sixth embodiment is shown in ( Figure 10 ), but it is not limited thereto. In other embodiments, the rate limiting unit 218A may also be added in a configuration using the fixed gain K in the fifth embodiment ( Figure 8 ) or in a configuration using the variable gain K corresponding to the magnitude of the load in the sixth embodiment ( Figure 9 ).

[0186] In addition, the rate of change may be a preset fixed value or variable. For example, the rate limiting unit 218A may change the rate of change according to the speed difference Δω between the high-speed rotor 12 and the low-speed rotor 13.

[0187] As described above, in the drive device 1 according to the present embodiment, the torque command value correction unit 218 of the control device 20 has the rate limiting unit 218A that limits the rate of change of the torque correction amount.

[0188] Thereby, when the drive device 1 performs torque adjustment to suppress out-of-step, sudden changes in the torque of the synchronous machine 10 can be suppressed.

[0189] Moreover, the rate limiting unit 218A changes the rate of change according to the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0190] Thereby, when the speed difference is large and a prompt response is required, by increasing the rate of change of the torque correction amount, the drive device 1 can quickly obtain the effect of suppressing out-of-step. On the other hand, when the speed difference is small and there is a margin before out-of-step occurs, sudden changes in torque can be suppressed.

[0191] <Eighth Embodiment>

[0192] Next, with reference to Figure 13 , the drive device 1 according to the eighth embodiment of the present invention will be described. The same reference numerals are assigned to the constituent elements common to the first to seventh embodiments, and detailed descriptions thereof are omitted.

[0193] In the fifth to seventh embodiments, an example in which the control device 20 processes the corrected torque command value to suppress out-of-step has been described. In contrast, in the present embodiment, an example in which the power converter 30 corrects the current command value to suppress out-of-step will be described.

[0194] (Functional Structure of Power Converter)

[0195] Figure 13 FIG. is a block diagram showing the functional structure of the power converter according to the eighth embodiment.

[0196] As Figure 13 shown, the power converter 30 includes a processor 31 and an inverter 32.

[0197] By operating according to a prescribed program, the processor 31 functions as a current command value generation unit 310, a speed measurement unit 311, and a current command value correction unit 312.

[0198] The current command value generation unit 310 generates a current command value corresponding to the torque command value input from the control device 20.

[0199] The speed measurement unit 311 measures the rotational speeds of the high-speed rotor 12 and the low-speed rotor 13 through the first sensor 16 and the second sensor 17. In addition, in the present embodiment, the speed measurement unit 311 measures the angular velocities [rad / s] of the two rotors respectively.

[0200] The current command value correction unit 312 calculates a current correction amount for damping the displacement angles of the high-speed rotor 12 and the low-speed rotor 13 in proportion to the speed difference between the high-speed rotor 12 and the low-speed rotor 13, and corrects the current command value.

[0201] The inverter 32 adjusts the power input and output between the synchronous machine 10 and the power converter 30 based on the corrected current command value.

[0202] (Regarding the Correction Process of Current Command Value)

[0203] Next, referring to Figure 13 , the details of the correction process of the current command value based on the power converter 30 will be described.

[0204] First, the current command value generation unit 310 of the power converter 30 generates a current command value based on the torque command value input from the control device 20. In addition, the method of generating a current command value from a torque command value is known, so the description thereof will be omitted. In addition, the torque command value input to the power converter 30 is the torque command value corrected by any one of the structures in the fifth to seventh embodiments.

[0205] Further, the speed measurement unit 311 obtains the angular velocity measurement value ωHSR of the high-speed rotor 12 and the angular velocity measurement value ωPPR of the low-speed rotor 13. Then, the current command value correction unit 312 calculates the speed difference Δω between the value obtained by multiplying the angular velocity measurement value ωPPR of the low-speed rotor 13 by the gear ratio Gr and the angular velocity measurement value ωHSR of the high-speed rotor 12.

[0206] Next, the current command value correction unit 312 multiplies the speed difference Δω between the two rotors by the gain K to calculate the current correction amount. In Figure 13 this example, the gain K is set to a variable value corresponding to the absolute value |Δω| of the speed difference, but it may also be set to a variable value corresponding to the magnitude of the absolute value |Istator| of the stator current value. The method for obtaining the value of the variable gain K is the same as that in the sixth embodiment. Also, in other embodiments, the gain K may be set to a fixed value.

[0207] Further, the current command value correction unit 312 outputs the corrected current command value to the inverter 32, and the corrected current command value is the sum value of the calculated current correction amount and the current command value generated by the current command value generation unit 310.

[0208] In addition, as in Figure 13 this example, the current command value correction unit 312 may also have a rate limiting unit 312A and limit the change rate of the calculated current correction amount. The change rate may be a preset fixed value or variable. For example, the rate limiting unit 312A may change the change rate according to the speed difference Δω between the high-speed rotor 12 and the low-speed rotor 13. Also, in other embodiments, the rate limiting unit 312A may be omitted.

[0209] The inverter 32 adjusts the power input and output between the synchronous machine 10 and the power converter 30 based on the corrected current command value. Specifically, when the synchronous machine 10 functions as a motor, the inverter 32 adjusts the power supplied to the stator 11 of the synchronous machine 10 based on the corrected current command value. Also, when the synchronous machine 10 functions as a generator, the inverter 32 adjusts the output power of the synchronous machine 10 based on the corrected current command value.

[0210] (Function, Effect)

[0211] As described above, in the drive device 1 according to the present embodiment, the power converter 30 includes: a current command value generation unit 310 that generates a current command value corresponding to a torque command value input from the control device 20; a speed measurement unit 311 that measures the rotational speeds (angular velocities) of the high-speed rotor 12 and the low-speed rotor 13; a current command value correction unit 312 that calculates a current correction amount for damping the displacement angles of the high-speed rotor 12 and the low-speed rotor 13 in proportion to the speed difference between the high-speed rotor 12 and the low-speed rotor 13, and corrects the current command value; and an inverter 32 that adjusts the power input and output between the synchronous machine based on the corrected current command value.

[0212] Generally, the power converter 30 is closer to the synchronous machine 10 as the control object than the upper control device 20 and performs control operations at high speed. Therefore, by correcting the current command value by the power converter 30, compared with the case of issuing a command from the control device 20, the influence of communication delay and calculation delay can be reduced, and the effect of suppressing out-of-step can be obtained more quickly.

[0213] As described above, several embodiments of the present invention have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. Regarding these embodiments and their modifications, they are included in the scope of the invention and the gist in the same way as they are included in the scope of the invention described in the claims and the scope of equivalents thereof.

[0214] <Supplementary Note>

[0215] The drive device and the control method of the drive device described in the above embodiment are understood as follows, for example.

[0216] (1) According to the first aspect of the present invention, the drive device 1 includes: a synchronous machine 10 having a high-speed rotor 12 and a low-speed rotor 13; and a control device 20 that controls the operation of the synchronous machine 10. The control device 20 includes: a torque command value acquisition unit 216 that acquires a torque command value for adjusting the torque output by the synchronous machine 10; a speed measurement unit 217 that measures the rotational speeds of the high-speed rotor 12 and the low-speed rotor; and a torque command value correction unit 218 that calculates a torque correction amount for damping the change speed of the magnetic displacement angles of the high-speed rotor 12 and the low-speed rotor 13 in proportion to the speed difference between the high-speed rotor 12 and the low-speed rotor 13, and corrects the torque command value.

[0217] Thus, by adjusting the torque output by the synchronous machine 10, the drive device 1 can apply rotor torsional damping to the magnetic torsion of the high-speed rotor 12 and the low-speed rotor 13. As a result, the drive device 1 can make the displacement angles of the high-speed rotor 12 and the low-speed rotor 13 less likely to change, thereby suppressing the occurrence of out-of-step. Also, the drive device 1 does not rely on estimating the rotational speeds of the high-speed rotor 12 and the low-speed rotor 13, but directly measures them through the first sensor 16 and the second sensor 17. Therefore, even when a large load change occurs, the accurate rotational speeds can be measured. Thus, the drive device 1 can obtain appropriate rotor torsional damping corresponding to the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0218] (2) According to the second aspect of the present invention, in the drive device 1 according to the first aspect, the torque command value correction unit 218 calculates a torque correction amount by multiplying the speed difference between the high-speed rotor 12 and the low-speed rotor 13 by a prescribed gain K.

[0219] Thus, the drive device 1 can adjust the magnitude of the rotor torsional damping by the value of the gain K.

[0220] (3) According to the third aspect of the present invention, in the drive device 1 according to the second aspect, the torque command value correction unit 218 changes the value of the gain K according to the magnitude of the load on the synchronous machine 10.

[0221] Thus, even if the magnetic gear has non-linear characteristics, that is, the restoring force of the magnetic spring changes depending on the operating point, the drive device 1 can effectively obtain rotor torsional damping. For example, when the drive device 1 is operating at a high load where out-of-step due to load fluctuations is likely to occur, it can increase the gain K to effectively suppress out-of-step. Also, when the load is low, by reducing the gain K, the drive device 1 can suppress the performance degradation caused by the rotor torsional damping.

[0222] (4) According to the fourth aspect of the present invention, in the drive device 1 according to the second aspect, the torque command value correction unit 218 changes the value of the gain K according to the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0223] Thus, even if the magnetic gear has non-linear characteristics, that is, the restoring force of the magnetic spring changes depending on the operating point, the drive device 1 can effectively obtain rotor torsional damping. For example, when the speed difference becomes large due to a sudden load change, the drive device 1 can increase the gain K to make the rotor torsional damping act strongly and effectively suppress out-of-step. On the other hand, when the speed difference is small, the drive device 1 regards the system as a stable state and can suppress the performance degradation of the synchronous machine 10 caused by the rotor torsional damping by reducing the gain K.

[0224] (5)According to the fifth aspect of the present invention, in the drive device 1 according to any one of the first to fourth aspects, the torque command value correction unit 218 has a rate limiting unit 218A that limits the rate of change of the torque correction amount.

[0225] Thereby, when the drive device 1 performs torque adjustment to suppress out-of-step, it can suppress torque mutation of the synchronous machine 10.

[0226] (6)According to the sixth aspect of the present invention, in the drive device 1 according to the fifth aspect, the rate limiting unit 218A changes the rate of change according to the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0227] Thereby, in the case where the speed difference is large and rapid response is required, by increasing the rate of change of the torque correction amount, the drive device 1 can quickly obtain the effect of suppressing out-of-step. On the other hand, in the case where the speed difference is small and there is a margin before out-of-step occurs, it can suppress torque mutation.

[0228] (7)According to the seventh aspect of the present invention, the drive device 1 according to any one of the first to sixth aspects further includes a power converter 30 that adjusts the power input and output between the power converter 30 and the synchronous machine 10. The power converter 30 includes: a current command value generation unit 310 that generates a current command value corresponding to the torque command value input from the control device 20; a speed measurement unit 311 that measures the rotational speeds of the high-speed rotor 12 and the low-speed rotor 13; a current command value correction unit 312 that calculates a current correction amount for damping the magnetic displacement angle of the high-speed rotor 12 and the low-speed rotor 13 in a manner proportional to the speed difference between the high-speed rotor 12 and the low-speed rotor 13, and corrects the current command value; and an inverter 32 that adjusts the power input and output between the power converter 30 and the synchronous machine 10 based on the corrected current command value.

[0229] Thereby, compared with the case of issuing an instruction from the control device 20, the drive device 1 can reduce the influence of communication delay and calculation delay, and thus obtain the effect of suppressing out-of-step more quickly.

[0230] (8)According to the eighth aspect of the present invention, in the control method of the drive device 1, the drive device 1 includes: a synchronous machine 10 having a high-speed rotor 12 and a low-speed rotor 13; and a control device 20 that controls the operation of the synchronous machine 10. The control method of the drive device 1 has the following steps: obtaining a torque command value for adjusting the torque output by the synchronous machine 10; measuring the rotational speeds of the high-speed rotor 12 and the low-speed rotor 13; and calculating a torque correction amount for damping the change speed of the magnetic displacement angle of the high-speed rotor 12 and the low-speed rotor 13 in a manner proportional to the speed difference between the high-speed rotor 12 and the low-speed rotor 13, and correcting the torque command value.

[0231] Industrial applicability

[0232] According to the above method, even when there is a large load change or the operating point of the magnetic spring changes significantly, effective rotor torsional damping can be obtained.

[0233] Symbol Explanation

[0234] 1 - driving device, 10 - synchronous machine, 11 - stator, 12 - high-speed rotor, 13 - low-speed rotor, 20 - control device, 21 - processor, 210 - acquisition unit, 211 - torque estimation unit, 212 - displacement angle estimation unit, 213 - displacement angle measurement unit, 214 - determination unit, 215 - adjustment unit, 216 - torque command value acquisition unit, 217 - speed measurement unit, 218 - torque command value correction unit, 218A - rate limiting unit, 22 - memory, 23 - storage device, 24 - interface, 30 - power converter, 31 - processor, 310 - current command value generation unit, 311 - speed measurement unit, 312 - current command value correction unit, 312A - rate limiting unit, 32 - inverter.

Claims

1. A driving device includes: a synchronous machine having a high-speed rotor and a low-speed rotor; and a control device for controlling the operation of the synchronous machine, wherein, the control device includes: a torque command value acquisition unit that acquires a torque command value for adjusting the torque output by the synchronous machine; a speed measurement unit that measures the rotational speeds of the high-speed rotor and the low-speed rotor; and a torque command value correction unit that calculates a torque correction amount for damping the change speed of the magnetic displacement angle of the high-speed rotor and the low-speed rotor in a manner proportional to the speed difference between the high-speed rotor and the low-speed rotor, and corrects the torque command value.

2. The driving device according to claim 1, wherein, the torque command value correction unit calculates the torque correction amount by multiplying the speed difference between the high-speed rotor and the low-speed rotor by a predetermined gain.

3. The driving device according to claim 2, wherein, the torque command value correction unit changes the value of the gain according to the magnitude of the load of the synchronous machine.

4. The driving device according to claim 2, wherein, the torque command value correction unit changes the value of the gain according to the speed difference between the high-speed rotor and the low-speed rotor.

5. The driving device according to claim 1, wherein, the torque command value correction unit has a rate limiting unit that limits the change rate of the torque correction amount.

6. The driving device according to claim 5, wherein, the rate limiting unit changes the change rate according to the speed difference between the high-speed rotor and the low-speed rotor.

7. The driving device according to any one of claims 1 to 6, wherein, the driving device further includes a power converter that adjusts the power input and output between the driving device and the synchronous machine, the power converter includes: a current command value generation unit that generates a current command value corresponding to the torque command value input from the control device; a speed measurement unit that measures the rotational speeds of the high-speed rotor and the low-speed rotor; a current command value correction unit that calculates a current correction amount for damping the magnetic displacement angle of the high-speed rotor and the low-speed rotor in a manner proportional to the speed difference between the high-speed rotor and the low-speed rotor, and corrects the current command value; and an inverter that adjusts the power input and output between the driving device and the synchronous machine based on the corrected current command value.

8. A control method for a driving device, the driving device including: a synchronous machine having a high-speed rotor and a low-speed rotor; and a control device for controlling the operation of the synchronous machine, the control method for the driving device having the following steps: acquiring a torque command value for adjusting the torque output by the synchronous machine; measuring the rotational speeds of the high-speed rotor and the low-speed rotor; and calculating a torque correction amount for damping the change speed of the magnetic displacement angle of the high-speed rotor and the low-speed rotor in a manner proportional to the speed difference between the high-speed rotor and the low-speed rotor, and correcting the torque command value.

Images