Drive unit and control method for drive unit

Abstract

To provide a drive device that can suppress step-out even when a twist angle changes sharply.SOLUTION: A drive device includes: a synchronous machine which has a high-speed rotor and a low-speed rotor; and a control device which controls the operation of the synchronous machine. The control device includes: a torque estimation unit that estimates the torque output by the synchronous machine on the basis of a current value of the power driving the synchronous machine; a torsion angle estimation unit that estimates the magnetic torsion angle between the high-speed rotor and the low-speed rotor on the basis of the estimation value of the torque; a torsion angle measurement unit which measures the torsion angle of the high-speed rotor and the low-speed rotor; a determination unit which determines whether or not a difference between the estimation value and the measurement value of the torsion angle exceeds a prescribed threshold; and an adjustment unit which outputs a torque command to increase or decrease the torque of the synchronous machine when it is determined that the difference exceeds the threshold.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This disclosure relates to a drive device and a method for controlling a drive device. [Background technology]

[0002] A magnetic geared motor comprises a high-speed rotor, a low-speed rotor, and a stator arranged on concentric axes. By supplying alternating current to the coils of the stator, the high-speed rotor rotates, and the rotation of the high-speed rotor causes the low-speed rotor to rotate at a predetermined reduction ratio.

[0003] A magnetic geared motor will lose synchronization if the magnetic helix angle between the high-speed and low-speed rotors exceeds 90 degrees statically. Therefore, adjusting the output of the magnetic geared motor, or the load (or prime mover) connected to it, so that the helix angle does not exceed 90 degrees will reduce the likelihood of losing synchronization.

[0004] As a method to suppress step loss, for example, Patent Document 1 describes reducing the rotational output of a prime mover (turbine) when the twist angle between the drive-side rotating shaft on the prime mover side and the passive-side rotating shaft on the generator side exceeds an allowable range in a magnetic coupling that transmits the rotational output of a prime mover (turbine) to a generator. It also describes changing the allowable range of the twist angle according to the temperature around the magnetic coupling, taking into account that the magnetic force of the magnets used in the magnetic coupling decreases with increasing temperature. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-125991 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, since the rate at which the temperature changes is significantly slower than the rate at which the torsion angle changes, the method described in Patent Document 1 may have a reduced effect in preventing step loss in response to events that cause rapid changes in the torsion angle, such as sudden load changes.

[0007] The object of this disclosure is to provide a drive device and a control method for a drive device that can suppress step loss even when the torsion angle changes rapidly. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, the drive device comprises 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 estimation unit that estimates the torque output by the synchronous machine based on the current value of the power driving the synchronous machine, a torsion angle estimation unit that estimates the magnetic torsion angle between the high-speed rotor and the low-speed rotor based on the estimated torque, a torsion angle measurement unit that measures the torsion angle between the high-speed rotor and the low-speed rotor, a determination unit that determines whether the difference between the estimated and measured torsion angles exceeds a predetermined threshold, and an adjustment unit that outputs a torque command to increase or decrease the torque of the synchronous machine when it is determined that the difference exceeds the threshold.

[0009] According to one aspect of the present disclosure, a method for controlling a drive device comprises 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 method comprising: estimating the torque output by the synchronous machine based on the current value of the power driving the synchronous machine; estimating the magnetic twist angle between the high-speed rotor and the low-speed rotor based on the estimated torque; measuring the twist angle between the high-speed rotor and the low-speed rotor; determining whether the difference between the estimated and measured twist angles exceeds a predetermined threshold; and, if it is determined that the difference exceeds the threshold, outputting a torque command to increase or decrease the torque of the synchronous machine. [Effects of the Invention]

[0010] According to the above embodiment, it is possible to suppress step loss even when the torsion angle changes rapidly. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing the overall configuration of the drive device according to the first embodiment. [Figure 2] This is a block diagram showing the functional configuration of the control device according to the first embodiment. [Figure 3] This is a flowchart showing an example of the processing of the control device according to the first embodiment. [Figure 4] This is a diagram illustrating the function of the drive device according to the first embodiment. [Figure 5] This is a diagram illustrating the functions of the control device according to the second embodiment. [Figure 6] This is a diagram illustrating the functions of the control device according to the third embodiment. [Figure 7] This is a diagram illustrating the functions of the control device according to the fourth embodiment. [Figure 8] This is a block diagram showing the functional configuration of the control device according to the fifth embodiment. [Figure 9] This is a first block diagram showing the functional configuration of the control device according to the sixth embodiment. [Figure 10] This is a second block diagram showing the functional configuration of the control device according to the sixth embodiment. [Figure 11] This figure shows an example of a variable gain according to the sixth embodiment. [Figure 12] This is a block diagram showing the functional configuration of the control device according to the seventh embodiment. [Figure 13] This is a block diagram showing the functional configuration of a power converter according to the eighth embodiment. [Modes for carrying out the invention]

[0012] <First Embodiment> (Overall configuration of the drive system) Hereinafter, the drive device 1 according to the first embodiment of this disclosure will be described with reference to Figures 1 to 4. Figure 1 is a schematic diagram showing the overall configuration of the drive device according to the first embodiment. As shown in Figure 1, the drive unit 1 comprises a synchronous machine 10, a control device 20, and a power converter 30.

[0013] The synchronous machine 10 is a magnetic geared motor. The synchronous machine 10 functions as an electric motor or a generator. In this embodiment, an example of using the synchronous machine 10 as an electric motor will be described.

[0014] The synchronous machine 10 comprises a stator 11, a high-speed rotor 12, and a low-speed rotor 13. The stator 11 has a cylindrical shape centered on axis O and covers the high-speed rotor 12 and the low-speed rotor 13 from the outer circumference. The high-speed rotor 12 is rotatable around axis O. The low-speed rotor 13 is positioned between the stator 11 and the high-speed rotor 12 and is rotatable around axis O. When current is supplied from the power converter 30 to the coils of the stator 11, the high-speed rotor 12 rotates. Also, when the high-speed rotor 12 rotates, the low-speed rotor 13 rotates at a predetermined reduction ratio. The low-speed rotor 13 is connected to a load by a rotating shaft 15, and the load is driven by the rotation of the rotating shaft 15 together with the low-speed rotor 13.

[0015] The control device 20 controls the operation of the synchronous machine 10. In particular, the control device 20 according to this embodiment outputs a torque command to adjust the torque output by the synchronous machine 10 in order to suppress step loss between the high-speed rotor 12 and the low-speed rotor 13 of the synchronous machine 10.

[0016] The power converter 30 supplies current to the coils of the stator 11 of the synchronous machine 10 so that the synchronous machine 10 can output torque in accordance with the torque command from the control device 20.

[0017] (Functional configuration of the control unit) Figure 2 is a schematic diagram showing the overall configuration of the drive device according to the first embodiment. As shown in Figure 2, the control device 20 includes a processor 21, memory 22, storage 23, and interface 24.

[0018] The processor 21 operates according to a predetermined program, performing functions as an acquisition unit 210, a torque estimation unit 211, a torsion angle estimation unit 212, a torsion angle measurement unit 213, a determination unit 214, and an adjustment unit 215.

[0019] The acquisition unit 210 acquires measured values ​​from the sensors of the synchronous machine 10. In this embodiment, the acquisition unit 210 acquires measured values ​​for detecting the helix angles of the high-speed rotor 12 and the low-speed rotor 13 from a first sensor 16 provided on the rotation shaft 14 of the high-speed rotor 12 and a second sensor 17 provided on the rotation shaft 15 of the low-speed rotor 13. The acquisition unit 210 also acquires the current value of the power driving the synchronous machine 10 from an ammeter 18 provided on the power line between the power converter 30 and the coil of the stator 11.

[0020] The torque estimation unit 211 estimates the torque output by the synchronous machine 10 based on the current value of the power driving the synchronous machine 10.

[0021] The twist angle estimation unit 212 estimates the twist angle between the high-speed rotor 12 and the low-speed rotor 13 based on the torque estimation value.

[0022] The twist angle measuring unit 213 estimates the twist angle between the high-speed rotor 12 and the low-speed rotor 13 based on the measured values ​​of the first sensor 16 and the second sensor 17.

[0023] The determination unit 214 determines whether the difference between the estimated twist angle and the measured twist angle exceeds a predetermined threshold.

[0024] The adjustment unit 215 outputs a torque command to increase or decrease the torque of the synchronous machine 10 when it determines that the difference between the estimated twist angle and the measured twist angle exceeds a threshold.

[0025] Memory 22 has a memory area necessary for the operation of the processor 21.

[0026] Storage 23 is a so-called auxiliary storage device, such as an HDD (Hard Disk Drive) or SSD (Solid State Drive).

[0027] Interface 24 is an interface for sending and receiving various types of information with external devices (such as the power converter 30).

[0028] The predetermined program executed by the processor 21 of the control device 20 is stored on a computer-readable recording medium. A computer-readable recording medium refers to a magnetic disk, magneto-optical disk, CD-ROM, DVD-ROM, semiconductor memory, etc. Alternatively, this computer program may be distributed to a computer via a communication line, and the computer that receives the distribution may execute the program. Furthermore, this program may be intended to implement only a part of the functions described above. Moreover, it may be a program that can implement the above functions in combination with a program already recorded in the computer system, a so-called differential file (differential program).

[0029] (Processing flow of the control unit) Figure 3 is a block diagram showing the functional configuration of the control device according to the first embodiment. The following will explain in detail the processing flow of the control device 20 with reference to Figure 3.

[0030] First, the acquisition unit 210 acquires measured values ​​from each sensor of the synchronous machine 10 (step S10). Specifically, the acquisition unit 210 acquires the current value of the synchronous machine 10 from the ammeter 18, and also acquires measured values ​​from the first sensor 16 and the second sensor 17.

[0031] Furthermore, the torque estimation unit 211 calculates the torque estimate value ^τ output by the synchronous machine 10 based on the current value. m Calculate (Step S11).

[0032] Based on the assumption that the load torque is balanced with the torque output by the synchronous machine 10 (in a steady state), the twist angle estimation unit 212 estimates the twist angle ^θ m between the high-speed rotor 12 and the low-speed rotor 13 of the synchronous machine 10 based on the torque estimated value ^τ e (step S12). For example, the twist angle estimation unit 212 uses the maximum transmission torque τ max of the synchronous machine 10 to calculate the twist angle estimated value ^θ e according to the following formula (1). This twist angle estimated value ^θ e serves as an indicator of a steady (or quasi-steady) load state.

[0033]

Equation

[0034] Next, based on the measured values of the first sensor 16 and the second sensor 17, the twist angle measurement unit 213 obtains the twist angle measured value θ e between the high-speed rotor 12 and the low-speed rotor 13 of the synchronous machine 10 (step S13).

[0035]

[0036] When the load changes suddenly, the balance of the torque is disrupted, and a deviation occurs between the twist angle estimated value ^θ e representing the steady twist angle and the twist angle measured value θ e which is the actual twist angle. In this embodiment, when the degree of this deviation exceeds the threshold value δ, the torque of the synchronous machine 10 is decreased (or increased) in a direction where the change in the twist angle is suppressed. e Specifically, first, the determination unit 214 calculates the twist angle upper limit value and the twist angle lower limit value based on the twist angle estimated value ^θ e (step S14). Specifically, the determination unit 214 calculates the twist angle upper limit value θ e,max and the twist angle lower limit value θ e,min based on the twist angle estimated value ^θ

[0037]

number

[0038]

number

[0039] The threshold value δ is a preset value, for example, 10 degrees. The value of the threshold value δ may be arbitrarily changed depending on the characteristics of the drive unit 1 and the operating conditions.

[0040] Next, the determination unit 214 determines the torsion angle measurement value θ. e The upper limit of the twist angle θ e,max Determine if it exceeds (Step S15).

[0041] Torsion angle measurement value θ e The upper limit of the twist angle θ e,max (θ) e >θ e,max If this is the case, the adjustment unit 215 outputs a torque command to reduce the torque of the synchronous machine 10 (step S16).

[0042] On the other hand, the measured value of the twist angle θ e The upper limit of the twist angle θ e,max (θ) e ≤θ e,max If this is the case, the determination unit 214 determines the torsion angle measurement value θ e The lower limit of the twist angle θ e,min Determine if it falls below that value (Step S17).

[0043] Torsion angle measurement value θ e The lower limit of the twist angle θ e,min (θ e <θ e,min If this is the case, the adjustment unit 215 outputs a torque command to increase the torque of the synchronous machine 10 (step S18).

[0044] On the other hand, the measured value of the twist angle θ e The lower limit of the twist angle θe,min If it is not below that value, i.e., the measured value of the torsion angle θ e The lower limit of the twist angle θ e,min The above is the upper limit of the twist angle θ. e,max If the torque is within the following normal range, the adjustment unit 215 terminates the process without changing the torque of the synchronous machine 10.

[0045] The power converter 30 adjusts the current supplied to the synchronous machine 10 based on the torque command input from the control device 20, so that the torque output by the synchronous machine 10 increases or decreases appropriately.

[0046] The control device 20 suppresses the synchronous machine 10 from losing synchronism by executing the series of processes shown in Figure 3 each time it measures (acquires) a measurement value while the synchronous machine 10 is being driven.

[0047] Figure 4 is a diagram illustrating the function of the drive device according to the first embodiment. Referring to Figure 4, the processing and operation of the drive unit 1 will be explained using the case where the load increases as an example.

[0048] Graph D10 in Figure 4 shows the time series of measured rotational speeds of the high-speed rotor 12 and low-speed rotor 13 of the synchronous machine 10. In graph D10, D101 represents the rotational speed of the high-speed rotor 12 corrected by the reduction ratio with the low-speed rotor 13, and D102 represents the rotational speed of the low-speed rotor 13.

[0049] In graph D11 of Figure 4, D111 is the measured twist angle θ. e D112 is the estimated twist angle ^θ e D113 is the upper limit of the twist angle θ e,max D114 is the lower limit of the twist angle θ e,min This represents the time series. Note that while Figure 4 is simplified, in reality, the estimated twist angle ^θ is used. e This value changes moment by moment depending on the current value. Similarly, the upper limit of the twist angle θ e,max and the lower limit of the twist angle θ e,min Estimated twist angle ^θ e The value will vary from moment to moment depending on the situation.

[0050] In graph D12 of Figure 4, D121 is the experimentally measured torque value τ of the synchronous machine 10. m D122 is the time series of torque commands T output by the control device 20.

[0051] In the example shown in graph D11 of Figure 4, the load increases at time t1, and the torsional angle measurement value θ e As the upper limit of the twist angle θ increases, e,max It exceeds [value]. Therefore, the adjustment unit 215 of the control device 20 outputs a torque command T at time t1 that reduces the torque of the synchronous machine 10.

[0052] Furthermore, at time t2, the measured value of the twist angle θ e The upper limit of the twist angle θ e,max The following occurs. In this case, the adjustment unit 215 of the control device 20 outputs a torque command T to the synchronous machine 10 at time t2 to generate torque according to the load. In the example in Figure 4, the adjustment unit 215 of the control device 20 outputs a torque command T to increase the torque at time t2.

[0053] In this way, the drive unit 1 increases the torsional angle due to the load, and the estimated torsional angle ^θ e and the measured twist angle θ e If the discrepancy with the measured value θ becomes large, the torque of the synchronous machine 10 is temporarily reduced to adjust the torsional angle measurement value θ. e The torsional angle estimate value ^θ follows the load condition. e The adjustment is made to approach this value. This prevents the drive unit 1 from losing steps if the torsion angle exceeds the limit value (90 degrees).

[0054] (Effect, Action) As described above, the drive device 1 according to this embodiment comprises 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 controls the torque estimate value τ output by the synchronous machine 10 based on the current value of the power driving the synchronous machine 10. m A torque estimation unit 211 estimates the torque, and the torque estimated value ^τ mBased on this, the estimated twist angle between the high-speed rotor 12 and the low-speed rotor 13 is ^θ. e The torsion angle estimation unit 212 estimates the torsion angle θ of the high-speed rotor 12 and the low-speed rotor 13. e The torsion angle measuring unit 213 measures the torsion angle and the estimated torsion angle ^θ. e and the measured value of the twist angle θ e A determination unit 214 determines whether the difference exceeds a predetermined threshold δ, and a twist angle estimate value ^θ. e and the measured value of the twist angle θ e The system includes an adjustment unit 215 that outputs a torque command T to increase or decrease the torque of the synchronous machine 10 when it is determined that the difference exceeds a threshold δ.

[0055] If the allowable range of the twist angle is always fixed (for example, fixed at 80 degrees, 10 degrees before the static limit of 90 degrees), there is a possibility that the torque operation will not be able to keep up with sudden and large load fluctuations, causing the motor to lose synchronism. On the other hand, if the allowable range is set too small to suppress the loss of synchronism, it becomes difficult to drive large loads (high-load operation). However, the drive device 1 according to this embodiment does not fix the allowable range of the twist angle, but rather uses the estimated twist angle value^θ estimated at each point in time. e The setting is dynamically changed based on a reference point, that is, based on the set value (motor operating point) in a steady state (or quasi-steady state). This makes it possible to suppress step-out in the high-speed rotor 12 and low-speed rotor 13 while also enabling high-load operation.

[0056] Furthermore, as mentioned above, in Patent Document 1, the allowable range is changed according to the temperature around the magnetic coupling, which can make it difficult to suppress step loss when the load changes rapidly. In contrast, the drive device 1 according to this embodiment uses an estimated torsional angle value ^θ as an indicator in response to changes in the current value of the synchronous machine 10. e By changing the actual twist angle measurement value θ e The system determines whether the difference exceeds the threshold δ. In this way, the drive unit 1 can quickly detect an increase in the twist angle due to a sudden change in load.

[0057] Furthermore, Patent Document 1 reduces the rotational output of the prime mover when the torsion angle exceeds the allowable range. In contrast, the drive device 1 according to this embodiment changes the torque of the synchronous machine 10 rather than the load (or prime mover), so it can suppress step loss while reducing the impact on the load (or prime mover). For example, the drive device 1 can suppress step loss while maintaining a high load state.

[0058] Furthermore, in the drive device 1 according to this embodiment, the adjustment unit 215 of the control device 20 controls the torsion angle measurement value θ e However, the estimated twist angle value ^θ e The upper limit θ is obtained by adding the threshold δ to the upper limit θ. e,max If it is determined that the torque exceeds a certain value, a torque command T is output to reduce the torque of the synchronous machine 10, and the torsional angle measurement value θ e However, the estimated twist angle value ^θ e The lower limit θ is obtained by subtracting the threshold δ from . e,min If the torque falls below a certain level, a torque command T is output to increase the torque of the synchronous machine 10.

[0059] In this way, the drive unit 1 can determine the estimated twist angle ^θ e The upper and lower limits of the twist angle can be varied accordingly. This allows the drive unit 1 to accurately determine whether or not the torque of the synchronous machine 10 should be adjusted without being overly sensitive to changes in the twist angle.

[0060] <Second Embodiment> Next, a drive device 1 according to a second embodiment of the present invention will be described with reference to Figure 5. Components common to the first embodiment are denoted by the same reference numerals and their detailed descriptions are omitted.

[0061] In the first embodiment, the determination unit 214 of the control device 20 used a fixed value for the threshold δ. In contrast, the determination unit 214 according to this embodiment changes the threshold δ according to the load state.

[0062] Figure 5 is a diagram illustrating the functions of the control device according to the second embodiment. Figure 5 shows graph D20, which represents an example of the torsional angle-torque characteristics, and graph D21, which represents an example of changing the threshold δ.

[0063] As shown in graph D21 of Figure 5, the determination unit 214 according to this embodiment changes the value of the threshold δ according to the magnitude of the estimated twist angle ^θe using a predetermined function. The synchronous machine 10 determines the twist angle θ e As the twist angle increases, the torque also increases, reaching its maximum transmitted torque when the twist angle θe reaches its limit value (90 degrees). e If the torque exceeds the limit, the synchronizer will lose synchronization. Also, as shown in graph D20, the synchronous machine 10 has a smaller tolerance for load fluctuations when the load is heavy (high torque) than when the load is light (low torque). In other words, the heavier the load, the more likely it is that the synchronizer will lose synchronization due to load fluctuations.

[0064] Therefore, the determination unit 214 determines the estimated twist angle value ^θ, as shown in the example of graph D21. e The closer it is to the limit value, the smaller the threshold δ is. As a result, the drive unit 1, for example, under high load conditions (operating point P2 in Figure 5), adjusts the estimated torsional angle ^θ. e Measured torsional angle θ e By responding sensitively to the degree of deviation, it is possible to more reliably suppress step loss. On the other hand, at low load (operating point P1 in Figure 5), the drive unit 1 controls the estimated torsional angle ^θ. e Measured torsional angle θ e This suppresses oversensitivity to the degree of deviation and prevents unnecessary torque adjustments.

[0065] The determination unit 214 determines the estimated twist angle ^θ. e Alternatively, a map or table may be prepared in advance that associates the threshold value with the threshold value δ, and the threshold value δ may be determined by referring to this map or table.

[0066] In this way, the drive unit 1 can finely adjust the torque according to the load condition, thereby more reliably suppressing step loss and improving the torque utilization rate of the synchronous machine 10.

[0067] <Third Embodiment> Next, a drive device 1 according to a third embodiment of the present invention will be described with reference to Figure 6. Components common to the first and second embodiments are denoted by the same reference numerals and their detailed descriptions are omitted.

[0068] The determination unit 214 of the control device 20 according to the first embodiment measures (acquires) each measurement value, and determines the torsion angle measurement value θ at each time point in time. e and estimated twist angle ^θ e The determination unit 214 according to this embodiment determines whether the difference exceeds the threshold δ. e and estimated twist angle ^θ e Determine whether the difference in the moving average values ​​exceeds the threshold δ.

[0069] Specifically, the estimated twist angle value ^θ for each time step estimated by the twist angle estimation unit 212. e , and the torsional angle measurement value θ measured at each time by the torsional angle measurement unit 213. e This is recorded in storage 23. In step S14 of Figure 3, the determination unit 214 determines the estimated torsion angle ^θ for the past n seconds from the determination time. e Based on the moving average value and the threshold δ, the upper and lower limits of the twist angle are calculated. In addition, in step S15 of Figure 3, the determination unit 214 calculates the twist angle measurement value θ for the past n seconds from the determination time. e The moving average value is determined to have exceeded the upper limit of the twist angle. Similarly, in step S17 of Figure 3, the determination unit 214 determines whether the measured twist angle θ for the past n seconds from the determination point. e Determine if the moving average of the values ​​falls below the lower limit of the twist angle.

[0070] In this way, the drive unit 1 is affected by noise and measurement errors, and the torsional angle measurement value θ is affected. e and the estimated twist angle ^θ e This can suppress the misjudgment that the difference exceeds the threshold δ.

[0071] Note that the determination unit 214 may use a fixed value for the averaging time n seconds, or it may be variable.

[0072] FIG. 6 is a diagram for explaining the functions of the control device according to the third embodiment. FIG. 6 shows a graph D30 representing an example of the twist angle-torque characteristic and a graph D31 representing an example of the change in the averaging time n.

[0073] As shown in the graph D31 of FIG. 6, the determination unit 214 may make the averaging time n (seconds) during moving average variable according to the load state using a predefined function. For example, the determination unit 214 shortens the averaging time n as the twist angle estimated value ^θ e gets closer to the limit value.

[0074] Note that the determination unit 214 may prepare in advance a map or table associating the twist angle estimated value ^θ e with the averaging time n, and determine the averaging time n by referring to this map or table.

[0075] By doing so, at low load (operation point P3 in FIG. 6), the drive device 1 can suppress misjudgment due to the influence of noise, measurement error, etc. by lengthening the averaging time n. Also, at high load (operation point P4 in FIG. 6), the drive device 1 can suppress the delay in determination due to the influence of past data before load fluctuation by shortening the averaging time n.

[0076] Note that in this embodiment, an example in which the determination unit 214 makes a determination based on the moving average values of the twist angle measured value θ e and the twist angle estimated value ^θ e has been described, but it is not limited thereto. In other embodiments, the determination unit 214 may determine whether or not a state where the difference between the twist angle measured value θ e and the twist angle estimated value ^θ e exceeds the threshold value δ continues for a determination time n (seconds) or more. Also, similar to the averaging time n, the determination unit 214 may change the determination time n according to the twist angle estimated value ^θ e .

[0077] Even in such a manner, the drive device 1 can suppress misjudgment due to the influence of noise, measurement error, etc.

[0078] <Fourth Embodiment> Next, the drive device 1 according to the fourth embodiment of the present invention will be described with reference to FIG. 7. The same reference numerals are given to the common components as those in the first to third embodiments, and the detailed description thereof will be omitted.

[0079] In the second embodiment, an example in which the determination unit 214 changes the threshold value δ according to the estimated twist angle ^θ e was described. Also, in the third embodiment, an example in which the determination unit 214 changes the averaging time n (determination time n) according to the estimated twist angle ^θ e was described. In contrast, the determination unit 214 according to the present embodiment changes at least one of the threshold value δ and the averaging time n (determination time n) based further on the state quantity that affects the maximum transmission torque.

[0080] Also, the acquisition unit 210 according to the present embodiment further acquires the state quantity that affects the maximum transmission torque of the synchronous machine 10. The state quantity that affects the maximum transmission torque is, for example, the coil temperature of the stator 11, the air gap 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. Also, as the air gap distance, a design value (initial value) may be used, or an estimated value or a measured value corresponding to the usage period of the synchronous machine 10 may be used in consideration of the change due to aging deterioration.

[0081] FIG. 7 is a diagram for explaining the functions of the control device according to the fourth embodiment. In FIG. 7, a graph D40 showing an example of the twist angle-torque characteristic, a graph D41 showing an example of the change in the threshold value δ, and a graph D42 showing an example of the change in the averaging time n (or determination time n) are shown.

[0082] This section describes an example using the coil temperature of the stator 11 as a state variable. Graph D41 shows the torsion angle-torque characteristics when the coil temperature is high (D401) and low (D402). It is assumed that the torsion angle-torque characteristics for each type and magnitude of state variable are pre-recorded in storage 23. As shown in graph D40, the maximum transmission torque is greater at low coil temperatures than at high coil temperatures. Furthermore, with the same load, a larger maximum transmission torque provides greater margin before step loss.

[0083] Based on these characteristics, the determination unit 214 prepares a function for determining the threshold δ for each temperature range of the coil temperature, for example, as shown in graph D41 in Figure 7. Although two functions are shown as examples in Figure 7, the determination unit 214 may prepare three or more functions. The determination unit 214 determines the threshold δ using the function corresponding to the coil temperature acquired by the acquisition unit 210. These functions are set so that even if the twist 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).

[0084] In this way, the determination unit 214 determines the magnitude of the maximum transmission torque corresponding to the state variable and the estimated twist angle ^θ. e This allows the threshold δ to be appropriately adjusted.

[0085] The determination unit 214 uses the state variable (coil temperature) and the estimated twist angle ^θ to determine the state variable (coil temperature) and the twist angle estimate. e Alternatively, a map or table may be prepared in advance that associates the threshold value δ with the threshold value, and the threshold value δ may be determined by referring to this map or table.

[0086] Furthermore, the determination unit 214, similar to the third embodiment, measures the torsion angle measurement value θ. e and estimated twist angle ^θ e The determination may also be made based on the moving average value of θ. e and estimated twist angle ^θ eThe determination unit 214 may determine whether the difference exceeds the determination time n. In this case, the determination unit 214 may make the averaging time n or the determination time n variable depending on the state variable.

[0087] As described above, when the same load is applied, the greater the maximum transmission torque, the greater the margin before step loss. Based on this characteristic, the determination unit 214 prepares a function for determining the averaging time n (or determination time n) for each temperature range of the coil temperature, as shown in graph D42 of Figure 7. Although two functions are shown as examples in Figure 7, the determination unit 214 may prepare three or more functions. The determination unit 214 determines the averaging time n (or determination time n) using the function corresponding to the coil temperature acquired by the acquisition unit 210. These functions are set so that even if the twist angle is the same (e.g., A1), the averaging time n (or determination time n) is longer when the coil temperature is low (operating point P7) than when the coil temperature is high (operating point P5).

[0088] In this way, the determination unit 214 determines the magnitude of the maximum transmission torque corresponding to the state variable and the estimated twist angle ^θ. e This allows for appropriate adjustment of the averaging time n (or the decision time n).

[0089] The determination unit 214 uses the state variable (coil temperature) and the estimated twist angle ^θ to determine the state variable (coil temperature) and the twist angle estimate. e Alternatively, a map or table can be prepared in advance that associates the average time n (or decision time n) with the average time, and the average time n (or decision time n) can be determined by referring to this map or table.

[0090] The determination unit 214 may vary both the threshold δ and the averaging time n (or determination time n) depending on the state variable, or it may vary only one of them.

[0091] In this way, the drive unit 1 can more reliably suppress step loss and improve the torque utilization rate of the synchronous machine 10 by finely adjusting the torque according to the state of the synchronous machine 10 in addition to the load state.

[0092] <Fifth Embodiment> Next, a drive device 1 according to the fifth embodiment of the present invention will be described with reference to Figure 8. Components common to the first to fourth embodiments are denoted by the same reference numerals and their detailed descriptions are omitted. In this embodiment of the drive device 1, the control device 20 performs control to suppress changes in the twist angles of the high-speed rotor 12 and the low-speed rotor 13 in response to load changes.

[0093] (Functional configuration of the control unit) Figure 8 is a block diagram showing the functional configuration of the control device according to the fifth embodiment. As shown in Figure 8, the processor 21 of the control device 20 according to this embodiment performs the functions of 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 predetermined program.

[0094] The torque command value acquisition unit 216 acquires a torque command value that adjusts the torque output by the synchronous machine 10. The torque command value is generated by the existing torque control means of the control device 20 according to the state of the load connected to the synchronous machine 10.

[0095] 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. In this embodiment, the speed measurement unit 217 measures the angular velocity [rad / s] of both rotors.

[0096] The torque command value correction unit 218 calculates a torque correction amount that dampens the magnetic twist 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.

[0097] (Regarding the correction process for torque command values) Next, with reference to Figure 8, the details of the torque command value correction process by the control device 20 will be explained. The angular velocity of the high-speed rotor 12 is ω HSR The angular velocity of the low-speed rotor 13 is ωPPR The gear ratio of both rotors is G r Therefore, while the high-speed rotor 12 and the low-speed rotor 13 are synchronized, the relationship in equation (4) holds true.

[0098]

number

[0099] Therefore, when a misalignment occurs between the high-speed rotor 12 and the low-speed rotor 13, outputting the torque obtained by equation (5) from the synchronous machine 10 can achieve the same effect as increasing the shaft torsional damping. Note that K is the gain, which determines the magnitude of the applied shaft torsional damping.

[0100]

number

[0101] Specifically, the torque command value correction unit 218 of the control device 20 first measures the angular velocity measurement value ω of the low-speed rotor 13. PPR The result of multiplying this by the gear ratio Gr of the high-speed rotor 12 and the low-speed rotor 13, and the measured angular velocity ω of the high-speed rotor 12. HSR Calculate the velocity difference Δω.

[0102] Next, the torque command value correction unit 218 calculates a torque correction amount by multiplying the speed difference Δω of the two rotors by a gain K. For example, if 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. This suppresses an increase in the relative speed difference (rate of change in twist angle) between the high-speed rotor 12 and the low-speed rotor 13, thereby suppressing the occurrence of step loss.

[0103] In this embodiment, the gain K is a fixed value (for example, "5.0") that is set in advance according to the characteristics and operating conditions of the synchronous machine 10. The larger the gain K, the greater the axial torsional damping can be.

[0104] Furthermore, the torque command value correction unit 218 outputs a corrected torque command value to the power converter 30, which is the sum of the calculated torque correction amount and the torque command value acquired by the torque command value acquisition unit 216.

[0105] (Effect, Action) As described above, in the drive device 1 according to this 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 velocity 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 that dampens the rate of change of the magnetic twist 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.

[0106] In this way, the drive unit 1 can apply axial 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 unit 1 can suppress the occurrence of step loss by making it difficult for the torsional angles of the high-speed rotor 12 and the low-speed rotor 13 to change.

[0107] Furthermore, in order to effectively impart axial torsional damping, the phase (timing) of the rotational speed change must be accurately measured. For example, in the method described in Patent Document 2 above, if a large shift occurs from the linearization operating point (equilibrium point), such as when a large load change occurs, it becomes difficult to correctly estimate the rotational speed. For example, if there is an error in estimating the rotational speed, in extreme cases, if the phase is shifted by 180 degrees, it will result in negative damping, which will amplify the axial torsional vibration.

[0108] In contrast, the drive unit 1 according to this embodiment directly measures the rotational speed (angular velocity) of the high-speed rotor 12 and the low-speed rotor 13 through the first sensor 16 and the second sensor 17, without estimation. Therefore, it can accurately measure the rotational speed even when large load changes occur. As a result, the drive unit 1 can obtain appropriate shaft torsional damping according to the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0109] Furthermore, in the method described in Patent Document 1 above, the torsional angle, which is the difference in rotation angles between the high-speed rotor and the low-speed rotor, is monitored, and when it exceeds a threshold, i.e., when a sign of step loss is detected, the load is adjusted to suppress step loss. In this case, if the threshold is small, step loss may be more likely to occur when there is a load change at high load. Also, if the threshold is large, excessive load adjustment may occur at low load, which may reduce motor efficiency.

[0110] In contrast, the drive unit 1 according to this embodiment corrects the torque command value (applies shaft torsional damping) according to the speed difference between the high-speed rotor 12 and the low-speed rotor 13 to suppress step loss. Therefore, this torque command value correction control should always be operated while the drive unit 1 is running. This is 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, which has the same effect as turning off the correction control.

[0111]

number

[0112] Therefore, the control device 20 according to this embodiment can omit complicated processes such as detecting signs of step loss and adjusting thresholds.

[0113] Furthermore, in the drive device 1 according to this embodiment, the torque command value correction unit 218 of the control device 20 calculates the torque correction amount by multiplying the speed difference between the high-speed rotor 12 and the low-speed rotor 13 by a predetermined gain K.

[0114] In this way, the drive unit 1 can adjust the magnitude of axial torsional damping by the value of the gain K.

[0115] <Sixth Embodiment> Next, the drive device 1 according to the sixth embodiment of the present invention will be described with reference to Figures 9 to 11. Components common to the first to fifth embodiments are denoted by the same reference numerals and their detailed descriptions are omitted.

[0116] Figure 9 is a first block diagram showing the functional configuration of the control device according to the sixth embodiment. As shown in Figure 9, in the control device 20 according to this embodiment, the torque command value correction unit 218 makes the value of gain K variable according to the load.

[0117] The magnitude of the load correlates with the magnitude of the current flowing through the stator 11 of the synchronous machine 10 (stator current value). Therefore, the torque command value correction unit 218 calculates the absolute value of the stator current value obtained from the ammeter 18 |I|. stator The value of gain K is changed according to the magnitude of |.

[0118] Figure 10 is a second block diagram showing the functional configuration of the control device according to the sixth embodiment. Furthermore, as shown in Figure 10, the torque command value correction unit 218 may vary the value of the gain K or the absolute value |Δω| of the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0119] Figure 11 shows an example of a variable gain according to the sixth embodiment. The synchronous machine 10 has a lower tolerance for load fluctuations when the load is heavy than when the load is light. In other words, the heavier the load, the more likely it is that step loss will occur due to load fluctuations. For this reason, when the value of gain K is changed according to the load, the torque command value correction unit 218 adjusts the absolute value of the stator current value |I| as shown in Figure 11. stator The larger the | (heavier the load), the larger the value of gain K should be.

[0120] Furthermore, in the synchronous machine 10, the greater the speed difference between the two rotors, the larger the torsional angle becomes, making it easier for the machine to lose step due to load fluctuations. For this reason, when changing the value of gain K according to the speed difference, the torque command value correction unit 218 increases the value of gain K as the absolute value of the speed difference |Δω| increases, as shown in Figure 11.

[0121] As described above, in the drive device 1 according to this 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.

[0122] In this way, the drive unit 1 can effectively achieve axial torsional damping even if the restoring force of the magnetic spring changes depending on the nonlinearity of the magnetic gear, i.e., the operating point.

[0123] For example, the drive unit 1 can increase the gain K as the load increases, thereby increasing shaft torsional damping. This effectively suppresses step loss even during high-load operation where step loss due to load fluctuations is likely to occur. On the other hand, shaft torsional damping hinders the motion of the system. Therefore, when the load is light (the tolerance for load fluctuations is relatively large), the drive unit 1 can suppress performance degradation due to shaft torsional damping by decreasing the gain K.

[0124] Furthermore, for example, if the speed difference becomes large due to a sudden load fluctuation, the drive unit 1 can effectively suppress step loss by increasing the gain K to strongly apply shaft torsional damping. On the other hand, when the speed difference is small, that is, when the load is stable and the rotational speeds of both rotors are stable, it is desirable that the shaft torsional damping is 0. For this reason, when the speed difference is small, the drive unit 1 can suppress the performance degradation of the synchronous machine 10 due to shaft torsional damping by reducing the gain K, assuming that the system is in a stable state.

[0125] In other words, the control device 20 can achieve both the performance and stability (resistance to step-out) of the synchronous machine 10 by adjusting the strength of the axial torsional damping according to the state of the system.

[0126] In the example shown in Figure 11, the torque command value correction unit 218 pre-sets the absolute value of the stator current value |I stator |Or, a function showing the relationship between the absolute value of the speed difference|Δω| and the value of the gain K is defined, and the value of the gain K is determined based on this function, but is not limited to this. In other embodiments, the torque command value correction unit 218 determines the absolute value of the stator current value|I stator Alternatively, a table may be prepared in advance that correlates the absolute value of the speed difference|Δω| with the value of the gain K, and the value of the gain K may be determined by referring to this table. In addition, the torque command value correction unit 218 uses the absolute value of the stator current value|I stator Alternatively, a specific range of the absolute value of the velocity difference, Δω, may be set as a dead zone (gain K=0).

[0127] <Seventh Embodiment> Next, the drive device 1 according to the seventh embodiment of the present invention will be described with reference to Figure 12. Components common to the first to sixth embodiments are denoted by the same reference numerals and their detailed descriptions are omitted.

[0128] Figure 12 is a block diagram showing the functional configuration of the control device according to the seventh embodiment. As shown in Figure 12, in the control device 20 according to this embodiment, the torque command value correction unit 218 has a rate limit unit 218A.

[0129] The rate limit 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, the rate limit unit 218A performs a process to gradually increase the torque correction amount when a torque correction amount exceeding a predetermined rate of change is required.

[0130] Figure 12 shows an example in which a rate limiter 218A is added to the configuration using a variable gain K according to the speed difference in the sixth embodiment (Figure 10), but the system is not limited to this. In other embodiments, the rate limiter 218A may be added to the configuration using a fixed gain K in the fifth embodiment (Figure 8), or to the configuration using a variable gain K according to the load magnitude in the sixth embodiment (Figure 9).

[0131] The rate of change may be a predetermined fixed value or it may be variable. For example, the rate limit section 218A may change its rate of change according to the speed difference Δω between the high-speed rotor 12 and the low-speed rotor 13.

[0132] As described above, in the drive device 1 according to this embodiment, the torque command value correction unit 218 of the control device 20 has a rate limit unit 218A that limits the rate of change of the torque correction amount.

[0133] In this way, when the drive unit 1 adjusts the torque to prevent step loss, it can suppress a sudden change in the torque of the synchronous machine 10.

[0134] Furthermore, the rate limit section 218A changes its rate of change according to the speed difference between the high-speed rotor 12 and the low-speed rotor 13.

[0135] In this way, the drive unit 1 can quickly achieve the effect of suppressing step loss by increasing the rate of change of the torque correction amount when there is a large speed difference and a quick response is required. On the other hand, when the speed difference is small and there is a relatively long margin before step loss occurs, sudden changes in torque can be suppressed.

[0136] <Eighth Embodiment> Next, the drive device 1 according to the eighth embodiment of the present invention will be described with reference to Figure 13. Components common to the first to seventh embodiments are denoted by the same reference numerals and their detailed descriptions are omitted.

[0137] In the fifth to seventh embodiments, an example was described in which the control device 20 performs a process to correct the torque command value in order to suppress step loss. In contrast, in this embodiment, an example is described in which the power converter 30 corrects the current command value in order to suppress step loss.

[0138] (Functional configuration of power converters) Figure 13 is a block diagram showing the functional configuration of a power converter according to the eighth embodiment. As shown in Figure 13, the power converter 30 includes a processor 31 and an inverter 32.

[0139] The processor 31 performs the functions of a current command value generation unit 310, a speed measurement unit 311, and a current command value correction unit 312 by operating according to a predetermined program.

[0140] The current command value generation unit 310 generates a current command value corresponding to the torque command value input from the control device 20.

[0141] 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 this embodiment, the speed measurement unit 311 measures the angular velocity [rad / s] of both rotors.

[0142] The current command value correction unit 312 calculates a current correction amount that reduces the twist 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 current command value.

[0143] 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.

[0144] (Regarding the correction process for current command values) Next, with reference to Figure 13, the details of the current command value correction process by the power converter 30 will be explained. 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. The method for generating a current command value from a torque command value is known and therefore will not be explained. The torque command value input to the power converter 30 is the torque command value corrected according to one of the configurations of the fifth to seventh embodiments.

[0145] Furthermore, the speed measurement unit 311 measures the angular velocity ω of the high-speed rotor 12. HSR and the measured angular velocity ω of the low-speed rotor 13 PPR The current command value correction unit 312 then obtains the angular velocity measurement value ω of the low-speed rotor 13. PPR The result of multiplying this by the gear ratio Gr, and the measured angular velocity ω of the high-speed rotor 12. HSR Calculate the velocity difference Δω.

[0146] Next, the current command value correction unit 312 calculates the current correction amount by multiplying the speed difference Δω of the two rotors by the gain K. In the example in Figure 13, the gain K is a variable value corresponding to the absolute value of the speed difference |Δω|, but the absolute value of the stator current |I stator The variable gain K may be a variable value depending on the magnitude of |. The method for determining the value of the variable gain K is the same as in the sixth embodiment. In other embodiments, the gain K may be a fixed value.

[0147] Furthermore, the current command value correction unit 312 outputs a corrected current command value to the inverter 32, which is the sum of the calculated current correction amount and the current command value generated by the current command value generation unit 310.

[0148] Furthermore, the current command value correction unit 312 may have a rate limit unit 312A, as shown in the example in Figure 13, to limit the rate of change of the calculated current correction amount. The rate of change may be a predetermined fixed value or it may be variable. For example, the rate of change of the rate limit unit 312A may be changed according to the speed difference Δω between the high-speed rotor 12 and the low-speed rotor 13. In other embodiments, the rate limit unit 312A may be omitted.

[0149] 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 an electric 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.

[0150] (Effect, Action) As described above, in the drive device 1 according to this embodiment, 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 speed (angular velocity) 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 that attenuates the twist 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 current command value, and an inverter 32 that adjusts the power input and output to and from the synchronous machine based on the corrected current command value.

[0151] Generally, the power converter 30 is closer to the controlled synchronous machine 10 than the higher-level control device 20, and performs control calculations at high speed. Therefore, by correcting the current command value, the power converter 30 can reduce the effects of communication delay and calculation delay compared to when the control device 20 issues the command, and thus achieve the effect of suppressing step loss more quickly.

[0152] As described above, several embodiments relating to this disclosure 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.

[0153] <Note> The drive device and control method for the drive device described in the above-described embodiment can be understood, for example, as follows.

[0154] (1) According to a first aspect of the present disclosure, the drive unit 1 comprises 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 comprising: a torque estimation unit 211 that estimates the torque output by the synchronous machine 10 based on the current value of the power driving the synchronous machine 10; a torsion angle estimation unit 212 that estimates the magnetic torsion angle between the high-speed rotor 12 and the low-speed rotor 13 based on the torque estimation value; a torsion angle measurement unit 213 that measures the torsion angle between the high-speed rotor 12 and the low-speed rotor 13; a determination unit 214 that determines whether the difference between the estimated and measured torsion angles exceeds a predetermined threshold; and an adjustment unit 215 that outputs a torque command to increase or decrease the torque of the synchronous machine 10 when it is determined that the difference exceeds the threshold.

[0155] In this way, the drive unit 1 can quickly detect an increase in the torsional angle due to a sudden change in load. Furthermore, since the drive unit 1 changes the torque of the synchronous machine 10, it can suppress step loss while reducing the impact on the load (or prime mover). For example, the drive unit 1 can suppress step loss while maintaining a high load state.

[0156] (2) According to a second aspect of the present disclosure, in the drive device 1 according to the first aspect, the adjustment unit 215 outputs a torque command to reduce the torque of the synchronous machine 10 when it is determined that the measured value of the twist angle exceeds an upper limit obtained by adding a threshold to the estimated value of the twist angle, and outputs a torque command to increase the torque of the synchronous machine 10 when it is determined that the measured value of the twist angle falls below a lower limit obtained by subtracting a threshold from the estimated value of the twist angle.

[0157] In this way, the drive unit 1 can vary the upper and lower limits of the torsional angle according to the estimated torsional angle. As a result, the drive unit 1 can accurately determine whether or not the torque of the synchronous machine 10 should be adjusted without being overly sensitive to changes in the torsional angle.

[0158] (3) According to a third aspect of the present disclosure, in the drive device 1 according to the first or second aspect, the determination unit 214 changes the value of the threshold based on the estimated value of the twist angle.

[0159] In this way, the drive unit 1 can finely adjust the torque according to the load condition, thereby more reliably suppressing step loss and improving the torque utilization rate of the synchronous machine 10.

[0160] (4) According to the fourth aspect of the present disclosure, in the drive device 1 according to any one of the first to third aspects, the determination unit 214 determines that the threshold has been exceeded if the difference between the moving average value of the estimated twist angle and the moving average value of the measured twist angle exceeds the threshold, or if the condition in which the difference between the estimated twist angle and the measured twist angle exceeds the threshold continues for a determination time or longer.

[0161] In this way, the drive unit 1 can suppress the misjudgment that the difference between the measured torsional angle and the estimated torsional angle exceeds a threshold due to the influence of noise, measurement errors, etc.

[0162] (5) According to a fifth aspect of the present disclosure, in the drive device 1 according to the fourth aspect, the determination unit 214 changes the averaging time of the moving average value or the length of the determination time based on a state quantity that affects the maximum transmission torque of the synchronous machine 10.

[0163] In this way, the determination unit 214 can appropriately adjust the averaging time or determination time based on the magnitude of the maximum transmission torque corresponding to the state quantity and the estimated twist angle.

[0164] (6) According to a sixth aspect of the present disclosure, in a drive device 1 according to any one of the first to fifth aspects, the determination unit 214 changes the value of a threshold based on a state quantity that affects the maximum transmission torque of the synchronous machine 10.

[0165] In this way, the determination unit 214 can appropriately adjust the threshold value based on the magnitude of the maximum transmission torque corresponding to the state variable and the estimated twist angle.

[0166] (7) According to a seventh aspect of the present disclosure, a control method for a drive device 1 comprising a synchronous machine 10 having a high-speed rotor 12 and a low-speed rotor 13, and a control device 20 for controlling the operation of the synchronous machine 10, includes the steps of: estimating the torque output by the synchronous machine 10 based on the current value of the power driving the synchronous machine 10; estimating the magnetic twist angle between the high-speed rotor 12 and the low-speed rotor 13 based on the estimated torque; measuring the twist angle between the high-speed rotor 12 and the low-speed rotor 13; determining whether the difference between the estimated and measured twist angles exceeds a predetermined threshold; and, if it is determined that the difference exceeds the threshold, outputting a torque command to increase or decrease the torque of the synchronous machine 10. [Explanation of symbols]

[0167] 1. Drive unit 10 Synchronous machine 11 stata 12 High-speed rotor 13 Low-speed rotor 20 Control device 21 processors 210 Acquisition Department 211 Torque Estimation Unit 212 Twist Angle Estimation Unit 213 Twist angle measuring section 214 Judgment section 215 Adjustment section 216 Torque command value acquisition unit 217 Speed ​​measurement unit 218 Torque command value correction unit 218A Rate Limit Section 22 memory 23 Storage 24 Interfaces 30 Power Converters 31 processors 310 Current command value generation unit 311 Speed ​​measurement unit 312 Current command value correction unit 312A Rate Limit Section 32 Inverters

Claims

1. A drive device comprising 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 is A torque estimation unit that estimates the torque output by the synchronous machine based on the current value of the power driving the synchronous machine, A torsion angle estimation unit estimates the magnetic torsion angle between the high-speed rotor and the low-speed rotor based on the estimated torque, A torsion angle measuring unit for measuring the torsion angles of the high-speed rotor and the low-speed rotor, A determination unit that determines whether the difference between the estimated value and the measured value of the twist angle exceeds a predetermined threshold, An adjustment unit that outputs a torque command to increase or decrease the torque of the synchronous machine when it is determined that the difference exceeds the threshold, Equipped with, The adjustment unit is, If it is determined that the measured value of the twist angle exceeds the upper limit obtained by adding the threshold value to the estimated value of the twist angle, a torque command to reduce the torque of the synchronous machine is output. When the measured value of the twist angle falls below the lower limit obtained by subtracting the threshold from the estimated value of the twist angle, a torque command is output to increase the torque of the synchronous machine. Drive unit.

2. The determination unit changes the value of the threshold based on the estimated value of the twist angle. The drive device according to claim 1.

3. The determination unit determines that the threshold has been exceeded if the difference between the moving average of the estimated twist angle and the moving average of the measured twist angle exceeds the threshold, or if the difference between the estimated twist angle and the measured twist angle exceeds the threshold for a period of time or longer. The drive device according to claim 1.

4. The determination unit changes the averaging time of the moving average value or the length of the determination time based on the state quantity that affects the maximum transmission torque of the synchronous machine. The drive device according to claim 3.

5. The determination unit changes the value of the threshold based on a state quantity that affects the maximum transmission torque of the synchronous machine. A drive device according to any one of claims 1 to 4.

6. A control method for a drive device comprising 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 steps include: estimating the torque output by the synchronous machine based on the current value of the power driving the synchronous machine; The steps include: estimating the magnetic twist angle between the high-speed rotor and the low-speed rotor based on the estimated torque; A step of measuring the helix angle of the high-speed rotor and the low-speed rotor, The steps include determining whether the difference between the estimated and measured values ​​of the twist angle exceeds a predetermined threshold, If it is determined that the difference exceeds the threshold, the step of outputting a torque command to increase or decrease the torque of the synchronous machine, If it is determined that the measured value of the twist angle exceeds the upper limit obtained by adding the threshold value to the estimated value of the twist angle, the step of outputting a torque command to reduce the torque of the synchronous machine, The steps include: outputting a torque command to increase the torque of the synchronous machine when the measured value of the twist angle falls below a lower limit obtained by subtracting the threshold from the estimated value of the twist angle; A control method for a drive device having the following features.

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