Eccentricity amount calculation device and method for rotary electric machine, and controller for rotary electric machine

Abstract

To provide an eccentricity amount calculation device and method for a rotary electric machine that require the small number of previously measured or analyzed data for eccentricity amount calculation, can be performed in a system for driving the rotary electric machine, and are capable of accurately calculating an eccentricity amount; and a controller for the rotary electric machine.SOLUTION: An eccentricity amount calculation device 300 for a rotary electric machine comprises: a processor 370; and a memory 380 for storing a constant of a multi-phase motor and an eccentricity amount operation expression. The processor 370 acquires a voltage command to a winding of each phase of a motor or voltage applied to the winding of each phase and a current command to the winding of each phase or current flowing in the winding of each phase; and calculates an eccentricity amount of the motor on the basis of the acquired voltage command or voltage and current command or current and the constant of the motor and the eccentricity amount operation expression stored in the memory 380.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an eccentricity calculation device and method for a rotary electric machine, and a control device for a rotary electric machine, and particularly relates to a technique for obtaining an eccentricity amount from voltages and currents detected by a control device for a rotary electric machine.

Background Art

[0002] Rotary electric machines may fail due to aging deterioration. In particular, an electric motor, which is a rotary electric machine for driving the main shaft of a servo press machine, may be subjected to an excessive load on the bearing portion due to the vibration of the press machine. In the worst case, the bearing portion may be damaged, and an accident may occur in which the rotor and the stator of the electric motor come into contact with each other. Therefore, a method that can be detected in advance before the rotor and the stator come into contact is desired.

[0003] In order to detect the contact between the rotor and the stator in advance, it is sufficient to obtain the eccentricity amount of the rotor and / or the stator of the electric motor.

[0004] As an example of a method for obtaining the eccentricity amount of the rotor and / or the stator of an electric motor, Patent Document 1 discloses a method for estimating the eccentricity of a rotary electric machine by measuring the terminal voltage or winding current of each winding when a voltage is applied to at least three or more windings of the stator of a rotary electric machine including a stator provided with a plurality of windings along the circumferential direction and a rotor. The rotary electric machine consists of three phases of U, V, and W, and three windings are connected in series respectively. For example, the three windings of the U phase are located at intervals of 120° from each other. By measuring the terminal voltages of these three windings, the eccentricity state can be known and the eccentricity ratio can be estimated.

[0005] The invention of Patent Document 1 is an excellent technical idea that utilizes the fact that each winding constituting a certain phase of the electric motor is arranged at spatially different positions, and when the electric motor is eccentric, the terminal voltages of the respective windings become different values to obtain the eccentricity (eccentric amount). However, for each of the three windings of a certain phase, it is necessary to obtain the relationship between the eccentricity (eccentric amount) and the voltage, but there is a drawback that the number of this data increases. For example, when measuring voltage and current data at 3 points on the + side and 3 points on the - side in the x direction, 3 points on the + side and 3 points on the - side in the y direction, a total of 12 measurements are required, and it takes time for data measurement or analysis prepared in advance. Needless to say, more points are required to improve the accuracy. Also, if it were only necessary to obtain the eccentricity (eccentric amount) under a certain voltage and current condition, it might be possible to take such trouble, but it takes a great deal of effort to obtain the eccentric amount under various voltage and current conditions.

[0006] Furthermore, the invention of Patent Document 1 aims at measuring the eccentric amount of the electric motor during assembly, and does not disclose or suggest a device configuration that can easily measure the eccentric amount of the aged electric motor at the customer's site after the electric motor is sold. If the method of Patent Document 1 is used for measurement at the customer's site, a method of removing the electric motor installed in the customer's device, connecting a separately brought eccentric measurement unit and an externally driven electric motor to the removed electric motor for measurement can be considered, but it is not difficult to imagine that it takes a great deal of effort and cost to measure the eccentric amount.

[0007] As another example of a method for obtaining the eccentric amount of an electric motor, the invention of Patent Document 2 is a rotary machine system having a rotary machine and a power conversion device connected to the rotary machine, which includes a current measurement unit for measuring a phase current, a current vector calculation unit for calculating a current vector by performing a three-phase to two-phase conversion on the phase current, an analysis target amount calculation unit for calculating an analysis target amount based on the current vector, a feature amount waveform extraction unit for extracting a waveform in a specific frequency range based on the analysis target amount, and an abnormality degree calculation unit for calculating an abnormality degree based on the extracted waveform.

[0008] Since the invention of Patent Document 2 can detect the degree of abnormality (such as eccentricity) in a rotating machine system having a power conversion device connected to a rotating machine, it is considered that measurement at the customer site after the sale of the motor, which was difficult with the method of Patent Document 1 described above, is easier to achieve than the method of Patent Document 1. However, although the method of Patent Document 2 can detect eccentricity, it does not disclose a method for accurately estimating a specific eccentricity amount. If a specific eccentricity amount cannot be estimated with high accuracy, an abnormality determination with low accuracy will inevitably result.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] One embodiment according to the technology of the present disclosure provides an eccentricity amount calculation device and method for a rotating electric machine, and a control device for a rotating electric machine, which can calculate the eccentricity amount with high accuracy while having a small number of data for calculating the eccentricity amount to be measured or analyzed in advance when measuring the voltage and current of the rotating electric machine to estimate the eccentricity amount, and can be implemented in a system for driving the rotating electric machine.

Means for Solving the Problems

[0011] The invention according to the first aspect is an eccentricity calculation device for a rotating electric machine including a processor and a memory that stores arithmetic expressions for constants and eccentricity amounts of a polyphase rotating electric machine. The processor acquires a voltage command for each phase winding of the rotating electric machine or a voltage applied to each phase winding, and a current command for each phase winding or a current flowing through each phase winding, and calculates the eccentricity amount of the rotating electric machine based on the acquired voltage command or voltage, the current command or current, and the arithmetic expressions for the constants and eccentricity amount of the rotating electric machine stored in the memory. It is an eccentricity calculation device for a rotating electric machine.

[0012] According to the first aspect of the present invention, since a voltage command for each phase winding of a rotating electric machine or a voltage applied to each phase winding, and a current command for each phase winding or a current flowing through each phase winding are acquired, and the eccentricity amount of the rotating electric machine is calculated based on the acquired voltage command or voltage, the current command or current, and the arithmetic expressions for the constants and eccentricity amount of the rotating electric machine stored in advance, the eccentricity amount can be obtained with high accuracy, and further, the eccentricity amounts under various voltage and current conditions can be easily obtained.

[0013] In the eccentricity calculation device for a rotating electric machine according to the second aspect of the present invention, in the first aspect, it is preferable that the processor performs a coordinate transformation on the acquired voltage command or voltage into a voltage command or voltage in a control dc-qc coordinate, and performs a coordinate transformation on the acquired current command or current into a current command or current in a control dc-qc coordinate, and uses the coordinate-transformed voltage command or voltage and the coordinate-transformed current command or current for calculating the eccentricity amount of the rotating electric machine.

[0014] In the eccentricity calculation device for a rotating electric machine according to the third aspect of the present invention, in the second aspect, the arithmetic expression for the eccentricity amount includes a first arithmetic expression for calculating an eccentricity error angle that is the deviation angle between the dc-qc coordinate and the d-q coordinate, and it is preferable that the processor substitutes the constants of the rotating electric machine, the coordinate-transformed voltage command or voltage, and the coordinate-transformed current command or current into the first arithmetic expression to calculate the eccentricity error angle.

[0015] In the eccentric amount calculation device of the rotating electric machine according to the fourth aspect of the present invention, in any one of the first to third aspects, the constants of the rotating electric machine stored in the memory include any one or more of the phase resistance, d-axis inductance, q-axis inductance, and number of pole pairs of the rotating electric machine.

[0016] In the eccentric amount calculation device of the rotating electric machine according to the fifth aspect of the present invention, in the third aspect, the calculation formula of the eccentric amount includes a second calculation formula showing the relationship between the eccentric error angle and the eccentric amount, and it is preferable that the processor substitutes the eccentric error angle calculated by the first calculation formula into the second calculation formula to calculate the eccentric amount.

[0017] In the eccentric amount calculation device of the rotating electric machine according to the sixth aspect of the present invention, in the fifth aspect, the processor calculates the eccentric error angle under preset operating conditions for each set of windings composed of multiple phases of the rotating electric machine by the first calculation formula, and substitutes the calculated eccentric error angle for each winding into the second calculation formula including a virtual rotor radius, which is an unknown constant, and a virtual winding representative position to create a system of simultaneous equations, calculates the virtual rotor radius and the virtual winding representative position that satisfy the system of simultaneous equations, and preferably sets the calculated virtual rotor radius and the virtual winding representative position as the constants of the second calculation formula under the operating conditions.

[0018] It is a newly discovered matter in the present invention that the two constants (virtual rotor radius and virtual winding representative position) in the second calculation formula become substantially the same values regardless of the eccentric amount under the same operating conditions. As a result, there are fewer tests required to obtain the information (the above two constants) prepared in advance for calculating the eccentric amount, the time required to obtain the information to be prepared is short, and it becomes realistically possible to calculate the eccentric amount at the site where the rotating electric machine is used.

[0019] The eccentric amount calculation device for a rotating electric machine according to the seventh aspect of the present invention is, in any one of the first to sixth aspects, the set of windings composed of multiple phases of the rotating electric machine is two sets of a first winding and a second winding.

[0020] According to the seventh aspect of the present invention, even if the set of windings composed of multiple phases is two sets, the eccentric amount can be calculated.

[0021] The eccentric amount calculation device for a rotating electric machine according to the eighth aspect of the present invention is, in any one of the first to seventh aspects, the rotating electric machine is a motor or a generator. That is, not limited to motors, the eccentric amount of generators can also be calculated.

[0022] The invention according to the ninth aspect is a method executed by an eccentric amount calculation device for a rotating electric machine including a processor and a memory storing a constant and an arithmetic formula for the eccentric amount of a multi-phase rotating electric machine, the processor acquiring a voltage command to each phase winding of the rotating electric machine or a voltage applied to each phase winding, and a current command to each phase winding or a current flowing through each phase winding, and the processor calculating the eccentric amount of the rotating electric machine based on the acquired voltage command or voltage, the current command or current, the constant of the rotating electric machine stored in the memory, and the arithmetic formula for the eccentric amount.

[0023] The eccentric amount calculation method for a rotating electric machine according to the tenth aspect of the present invention is, in the ninth aspect, the step of the processor performing coordinate conversion of the acquired voltage command or voltage into a voltage command or voltage in a control dc-qc coordinate, and coordinate conversion of the acquired current command or current into a current command or current in a control dc-qc coordinate, and in the step of calculating the eccentric amount of the rotating electric machine, it is preferable to use the coordinate-converted voltage command or voltage and the coordinate-converted current command or current for calculating the eccentric amount of the rotating electric machine.

[0024] The invention according to the 11th aspect is a control device for a rotating electric machine, which includes a control unit that controls a polyphase rotating electric machine and operates a mechanical device by the rotating electric machine, and an eccentricity amount calculation device for the rotating electric machine according to any one of the 1st to 8th aspects.

[0025] The control device for a rotating electric machine according to the 12th aspect of the present invention is, in the 11th aspect, a speed control unit that outputs a torque command based on a deviation between a speed command for the rotating electric machine set in advance and the speed of the rotating electric machine, a mode selection unit that selects a normal operation mode for normally operating the rotating electric machine or an eccentricity amount calculation mode for calculating an eccentricity amount according to a selection instruction of an operator, a higher-level control device that outputs a switching signal for switching between the normal operation mode and the eccentricity amount calculation mode based on a mode command output from the mode selection unit, and a current command calculation unit that outputs a dc-axis current command and a qc-axis current command based on the torque command and the switching signal. When the normal operation mode is selected, the control unit outputs a dc-axis current command and a qc-axis current command for the normal operation mode from the current command calculation unit. When the eccentricity amount calculation mode is selected, the control unit outputs a dc-axis current command and a qc-axis current command for the eccentricity amount calculation mode from the current command calculation unit, or closes the brake to lock the rotor of the rotating electric machine, and preferably controls the dc-axis current command and the qc-axis current command output from the current command calculation unit to be a current that generates a steady alternating current or a voltage related to the magnetic flux linkage number of the motor winding of the rotating electric machine.

[0026] The control device for a rotating electric machine according to the 13th aspect of the present invention is, in the 11th aspect or the 12th aspect, provided with a display device that displays any one or more of an eccentricity amount, an eccentricity error angle, and a value corresponding to the eccentricity error angle. The control unit preferably causes the display device to display any one or more of the eccentricity amount, the eccentricity error angle, and the value corresponding to the eccentricity error angle calculated by the eccentricity amount calculation device.

[0027] The control device for a rotary electric machine according to the 14th aspect of the present invention, in any one of the 11th to 13th aspects, includes an abnormality warning device that warns of any one or more abnormalities among the eccentricity amount, the eccentricity error angle, and the value corresponding to the eccentricity error angle. The control unit compares any one or more of the eccentricity amount, the eccentricity error angle, and the value corresponding to the eccentricity error angle calculated by the eccentricity amount calculation device with a threshold value serving as an abnormality determination criterion, and when any one or more of the eccentricity amount, the eccentricity error angle, and the value corresponding to the eccentricity error angle are equal to or greater than the threshold value, it is preferable to cause the abnormality warning device to warn of the abnormality.

[0028] The control device for a rotary electric machine according to the 15th aspect of the present invention, in any one of the 11th to 14th aspects, the mechanical device is a servo press machine including the rotary electric machine, and it is preferable that the rotary electric machine rotates the main shaft of the servo press machine.

Advantages of the Invention

[0029] According to the present invention, when measuring the voltage and current of a rotary electric machine to estimate the eccentricity amount, the number of data for calculating the eccentricity amount that needs to be measured or analyzed in advance is small, and the eccentricity amount under various voltage and current conditions can be easily and accurately calculated.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Figure 33

Figure 34

Figure 35

Figure 36

Figure 37

Figure 38

Best Mode for Carrying Out the Invention

[0031] The preferred embodiments of an eccentric amount calculation device and method for a rotary electric machine and a control device for a rotary electric machine will be described in detail below with reference to the accompanying drawings.

[0032] FIG. 1 is an overall configuration diagram of a control device for a rotary electric machine including an eccentric amount calculation device for the rotary electric machine according to the present invention and a mechanical device equipped with the rotary electric machine.

[0033] The rotary electric machine shown in FIG. 1 is a polyphase electric motor 110, and the mechanical device equipped with the rotary electric machine (electric motor 110) is driven by the electric motor 110. [Electric Motor] FIG. 2 is a cross-sectional view of a main part of the electric motor shown in FIG. 1.

[0034] The electric motor 110 shown in FIG. 2 is a polyphase electric motor. In FIG. 2, a general three-phase (U-phase, V-phase, W-phase) electric motor will be described. Also, the electric motor 110 will be described by taking a synchronous electric motor as an example. However, as described in the second embodiment below, the eccentric amount calculation device and method, which are the main objects of the present invention, can be applied regardless of the type of the electric motor. Therefore, an induction motor may be used, or further, a generator that converts mechanical energy externally applied into electrical energy (electric power) may be used.

[0035] The windings of the U-phase, V-phase, and W-phase of the stator 110a of the electric motor 110 are each a plurality of Nw (≧2) windings U k , V k , W k (k = 1, 2,..., Nw) are each connected in series or in parallel, and terminals U, V, and W are led out to the terminal box (not shown) of the electric motor 110 as a set of polyphase windings. Also, the windings U k , V k , W k (k = 1, 2,..., Nw) will be referred to as the 'k-th winding'.

[0036] The windings of each of the Nw phases are located at intervals of 2π / Nw from each other, and the k-th winding and the adjacent (k-1)-th or (k+1)-th winding, which are a pair of them, are also located at intervals of 2π / Nw from each other. In FIG. 2, the windings of each phase are drawn without interfering with the windings of adjacent phases, but they may also interfere with each other.

[0037] Also, the motor 110 is provided with a rotor 110b. Permanent magnets are embedded in the rotor 110b, and it is configured as the rotor 110b of a permanent magnet synchronous motor. The rotor 110b rotates at a speed synchronized with the rotating magnetic field of the stator 110a. In the example of FIG. 2, a rotor 110b with 8 poles (4 pole pairs) is shown.

[0038] Also, magnetic poles may be provided on the rotor, field windings may be provided on the magnetic poles, and by exciting the field windings, N poles and S poles may be generated on the rotor. In the case of an induction motor, there are a wound type in which a polyphase winding similar to the stator winding is provided on the rotor, and a cage type in which conductor bars are passed through in the axial direction of the rotor and both ends thereof are electrically connected by a short-circuit ring. Since an induction motor generates an electromotive force in the conductor bars of the rotor and generates torque when there is a difference between the speed of the rotating magnetic field on the stator side (synchronous speed) and the speed of the rotor, the rotor rotates at a speed slower than the rotating magnetic field of the stator.

[0039] FIG. 3 is a connection diagram showing an example of the connection of the windings of the U-phase, V-phase, and W-phase of the motor shown in FIG. 2.

[0040] FIG. 3 shows an example in which the windings of each of the Nw phases are connected in series, but as described above, it is not limited to this, and they may be connected in parallel.

[0041] The motor 110 has terminals TU uk and TNU vk and TV wk and TNV k and TW k and TNW k and TNV k and TW k and TNW k(k = 1, 2, …, Nw) are respectively provided and are led out to a terminal box (not shown) of the electric motor 110. Also, the current i uk , i vk , i wk (k = 1, 2, …, Nw) can be measured, and between the terminals TU k and TNU k , between TV k and TNV k , between TW k and TNW k (k = 1, 2, …, Nw), current sensors S uk , S vk , S wk (k = 1, 2, …, Nw) are respectively provided.

[0042] In the case of FIG. 3, the current sensor for each phase can also be made one. [Control device for rotating electric machinery] In FIG. 1, the control device for the rotating electric machinery includes an eccentricity amount calculation device for the rotating electric machinery according to the present invention.

[0043] The electric motor 110 is provided with a drive shaft 112 on the side (load side) connected to the mechanical device of the rotor, and the drive shaft 112 is connected to the mechanical device.

[0044] The mechanical device is exemplified by a servo press machine 100 in FIG. 1. The details of the servo press machine will be described in the seventh embodiment described later. The mechanical device is not limited to the servo press machine, and may be, for example, an industrial machine such as an electric railway vehicle, an automobile, a construction machine such as a crane, etc. Also, it may be just the electric motor without the mechanical device.

[0045] The motor position sensor 116 detects the position of the motor 110 and is attached to the motor 110. In FIG. 1, it is attached to a rotating shaft coaxial with the drive shaft 112 of the motor 110, but is not limited thereto, and may be attached to the mechanical device side mechanically connected to the rotating shaft. A rotary encoder or the like is applied to the motor position sensor 116. The detected position is used for calculations such as coordinate conversion of well-known vector control and speed control calculations. In this example, a configuration with the motor position sensor 116 provided will be described, but a system that estimates and calculates the position from motor voltage, current information, etc., such as sensorless control, may also be used.

[0046] The control device for the rotating electric machine is provided with a current control device 220 that controls the current of the motor 110.

[0047] The current control device 220 is composed of a current control unit 230, a three-phase AC power supply 240, a converter 250, a servo amplifier (inverter) 260, a PWM (Pulse Width Modulation) conversion unit 270, and a current sensor 280.

[0048] The three-phase AC voltage command (v uc * , v vc * , v wc * ) output from the current control unit 230 is output to the PWM conversion unit 270, where it is PWM-converted and applied to the servo amplifier 260. To the other input of the servo amplifier 260, three-phase AC power from the three-phase AC power supply 240 is converted into DC power by the converter 250, and DC power is applied from the converter 250. The servo amplifier 260 is a device that converts DC power into three-phase AC power and is a well-known inverter. The servo amplifier 260 converts DC power into three-phase AC power according to the PWM-converted three-phase AC voltage command, and applies the converted three-phase AC power to the motor 110 to drive the motor 110.

[0049] The control device for the rotary electric machine in this example has a normal operation mode for normally operating the electric motor 110 and an eccentricity amount calculation mode, and the mode selection unit 212 outputs a mode command M indicating the normal operation mode or the eccentricity amount calculation mode in response to a selection instruction from the operator. * is output to the upper control device 210.

[0050] When the upper control device 210 inputs the mode command M indicating the normal operation mode from the mode selection unit 212, * it outputs a brake control command Bc for opening the brake 170 * to the brake control unit 172, and after the brake 170 is opened by the brake control unit 172, the electric motor 110 is normally operated. Also, when the upper control device 210 inputs the mode command M indicating the eccentricity amount calculation mode from the mode selection unit 212, * it outputs a brake control command Bc for opening or closing the brake 170 * to the brake control unit 172, and after the brake 170 is opened or closed by the brake control unit 172, the operation of the electric motor 110 is changed to an operation for calculating the eccentricity amount.

[0051] Next, the speed control and current control (vector control) system of the electric motor 110 will be briefly described.

[0052] A speed command N preset from the upper control device 210 * is output to the positive input of the adder. The speed N calculated by the speed calculation unit 214 is added to the negative input of the adder, and the adder obtains the deviation (N * - N) between the speed command N * and the speed N, and outputs the deviation (N * - N) to the speed control unit 213. The speed calculation unit 214 calculates the speed N based on the position θ re acquired by the electric motor position sensor 116.

[0053] The speed control unit 213 outputs a torque command T * corresponding to the deviation (N * . The torque command T *It is input to the dc-qc axis current command calculation unit 216.

[0054] FIG. 4 is a functional block diagram showing an example of the dc-qc axis current command calculation unit.

[0055] Another input to the dc-qc axis current command calculation unit 216 is a switching signal M for switching from the upper control device 210 between the normal operation mode and the eccentricity amount calculation mode dq * is added, and when the switching signal M dq * is a switching signal to the eccentricity amount calculation mode, the dc axis current command and the qc axis current command calculation unit 216A for the eccentricity amount calculation mode are selected, and the dc axis current command i for the eccentricity amount calculation mode dc * , qc axis current command i qc * is output (FIG. 4(A)), and when the switching signal M dq * is a switching signal to the normal operation mode, the dc axis current command and the qc axis current command calculation unit 216B for the normal operation mode are selected, and the dc axis current command i for the normal operation mode dc * , qc axis current command i qc * is output (FIG. 4(B)).

[0056] In the normal operation mode, the dc axis current command i dc * may be commanded, for example, to be 0, or may be commanded so that the maximum torque, the maximum efficiency, and the power factor = 1. i qc * is calculated and commanded, for example, from the torque equation of the electric motor 110 based on the torque command T * .

[0057] The i dc * , i qc * output in the eccentricity amount calculation mode will be described later.

[0058] Returning to FIG. 1, the dc-qc axis current command i dc * , qc axis current command i qc * is input to the current control section 230 and added to the positive input of each adder in the current control section 230. The dc-axis current i dc , qc axis current i qc The coordinate conversion unit 236 is a part that performs multi-phase / dc-qc conversion, and converts the three-phase AC current (i u , i v , i w ) and the position θ obtained by the motor position sensor 116 re Using the dc axial current i dc , qc axis current i qc As mentioned above, the position θ re may use a value estimated and calculated from voltage and current information, etc., by using position sensorless control.

[0059] dc axis current command i dc * and dc axial current i dc The adder that inputs the dc axis current command i dc * and dc axial current i dc Deviation from (i dc * -i dc ) and calculate the deviation (i dc * -i dc ) to the dc-axis current control unit 232, and the qc-axis current command i qc * and qc-axis current i qc The adder that inputs the qc-axis current command i qc * and qc-axis current i qc Deviation from (i qc * -i qc ) and calculate the deviation (i qc * -i qc ) to the qc-axis current control unit 234.

[0060] The DC-axis current control unit 232 outputs a DC-axis voltage command v dc * -i dc ) based on the input deviation (i dc * . The quadrature-axis current control unit 234 outputs a quadrature-axis voltage command v qc * -i qc ) based on the input deviation (i qc * .

[0061] The DC-axis current control unit 232 and the quadrature-axis current control unit 234 are configured by, for example, connecting a proportional controller (P control) and an integral controller (I control) in parallel. However, since the main object of the present invention is to calculate the amount of eccentricity, it is not limited thereto. A derivative controller (D control) may be further added in parallel to configure a so-called PID control. The key point is that i dc * follows i dc , and i qc * follows i qc . Any controller may be used as long as it is configured to perform control such that

[0062] The DC-axis voltage command v dc * , and the quadrature-axis voltage command v qc * are applied to the coordinate conversion unit 238. The coordinate conversion unit 238 is a part that performs DC-QC / polyphase conversion. Using the DC-axis voltage command v dc * , the quadrature-axis voltage command v qc * , and the position θ re acquired from the motor position sensor 116, it performs a rotational coordinate conversion to the three-phase AC voltage commands v uc * , v vc * , v wc * . As described above, the position θ re may use sensorless control and use a value estimated and calculated from voltage and current information or the like.

[0063] Three-phase AC voltage command v uc * 、v v c * 、v wc * is PWM-converted by the PWM conversion unit 270 as described above and then output to the servo amplifier 260, where it is amplified and output to the electric motor 110. As a result, the electric motor 110 is current-controlled (vector control).

[0064] The above applies equally to polyphase AC with three or more phases. If a configuration is adopted in which coordinate conversion is performed on the polyphase AC current synchronized with the rotor to generate a two-dimensional current vector and this is controlled, it is essentially the same whether it is three-phase or polyphase, and it goes without saying that it is not limited to three-phase.

[0065] Also, the control device for the rotating electric machine is provided with a voltage-current measuring unit 330 that measures the terminal voltage v uk 、v vk 、v wk of the k-th winding and the winding current i uk 、i vk 、i wk (k = 1, 2,..., Nw). One end of each of the Nw voltage sensor cables for each phase is connected to the terminals TU k and TNU k 、TV k and TNV k 、TW k and TNW k of the electric motor 110 described above. Current sensors S uk 、S vk 、S wk are provided between TU k and TNU k 、TV k and TNV k 、TW k and TNW k ,and one end of each of the Nw polyphase current sensor cables for each phase is connected to each of them. The other ends of these sensor cables are connected to the voltage-current measuring unit 330, and the terminal voltage v uk 、v vk 、v wk of the k-th winding and the winding current i uk 、i vk 、iwk Measure (k=1, 2, ..., Nw).

[0066] In addition, the control device of the rotating electric machine is the terminal voltage v of the kth winding. uk , v vk , v wk and the winding current i uk , i vk , i wk Using the measured values ​​of (k=1, 2, ..., Nw) and the position θre acquired by the motor position sensor 116, the dc-axis voltage v of the kth winding is calculated. dck , qc-axis voltage v qck , dc axis current i dck , qc axis current i qck A coordinate conversion unit 340 is provided to perform rotational coordinate conversion to (k=1, 2, ..., Nw). The position θre may be a value estimated and calculated from voltage and current information, etc., and the position value acquired by the motor position sensor 116 is not necessarily required.

[0067] However, if the position value obtained by the motor position sensor 116 is not used, it is necessary to simultaneously measure the voltage and current values ​​of each winding to clarify the phase relationship between the voltage and current of each winding. This is because the position θ re This is because it is necessary to perform coordinate conversion calculations using the above. When it is difficult to measure all windings simultaneously and, for example, only two windings can be measured simultaneously, a certain winding can be used as a reference and the other windings can be measured simultaneously with a reference winding, thereby obtaining the same effect as when all windings are measured simultaneously. Furthermore, the voltage / current measuring unit 330 and / or the coordinate conversion unit 340 are not limited to those provided in the control device of the rotating electric machine, and may be provided in the eccentricity calculation device for the rotating electric machine.

[0068] The eccentricity calculation device 300 includes an eccentricity error angle calculation section 310 and an eccentricity amount calculation section 320 .

[0069] The eccentricity calculation device 300 calculates the v of the k-th winding input from the coordinate conversion unit 340. dck , v qck , i dck , i qckValues of (k = 1, 2, …, Nw), motor constants that are constants of the rotary electric machine, and a virtual rotor radius r and a virtual winding representative position (angle) θ that are constants that can be calculated in advance rmck From this, the amount of eccentricity is calculated. The method for calculating the amount of eccentricity will be described later.

[0070] The eccentricity display device 350, which is a display device, displays the calculated amount of eccentricity, but may display one or more of the amount of eccentricity, the eccentricity error angle, and values corresponding to the eccentricity error angle. The abnormality warning device 360 inputs the amount of eccentricity (a1, a2) and the eccentricity error angle Δθ from the eccentricity calculation device 300 rmk , and one or more of the values corresponding to the eccentricity error angle (the value of tanΔθ described later rmk is compared with a threshold value that serves as an abnormality determination criterion, and if it is less than the threshold value, 'normal' is output, and if it is greater than or equal to the threshold value, 'abnormal' is output. The eccentricity display device 350 and the abnormality warning device 360 may be the same device. Also, as shown in the seventh embodiment described later, the eccentricity and the warning content may be displayed on the operation display of the main operation panel of the servo press machine 100. [Hardware Configuration of Eccentricity Calculation Device for Rotary Electric Machine] FIG. 5 is a block diagram showing the hardware configuration of the eccentricity calculation device for a rotary electric machine according to the present invention.

[0071] The eccentricity calculation device shown in FIG. 5 is configured by, for example, a computer and includes a processor 370, a memory 380, and an input / output interface 390. This eccentricity calculation device 300 is incorporated in the control device of the rotary electric machine as shown in FIG. 1.

[0072] The processor 370 is composed of a CPU (Central Processing Unit) or the like, executes various programs including firmware and programs for calculating the eccentricity stored in the memory 380, controls each part of the eccentricity calculation device in an overall manner, and executes processing for calculating the eccentricity, and functions as the eccentricity error angle calculation unit 310 and the eccentricity calculation unit 320 shown in FIG. 1.

[0073] The memory 380 includes a flash memory, a ROM (read-only memory), a RAM (random access memory), a hard disk device, etc. The flash memory, ROM, or hard disk device is a non-volatile memory that stores various programs including firmware.

[0074] The RAM functions as a working area for processing by the processor and temporarily stores programs and the like stored in the flash memory or the like. Note that the processor 370 may incorporate a part (RAM) of the memory 380.

[0075] Also, the memory 380 stores the motor constant of the electric motor 110, the virtual rotor radius r, the virtual winding representative position (angle) θ of the k-th winding rmck (k = 1, 2,..., Nw), and the calculation formula for the eccentricity. In this embodiment, the motor constant is the phase resistance Ra of the electric motor 110 and the d-axis inductance L d , q-axis inductance L q , and the number of pole pairs p. As will be described later, in another embodiment, a method that does not require the d-axis inductance L d , q-axis inductance L q is also shown. In that case, it is only necessary to store the phase resistance Ra of the electric motor and the number of pole pairs. Note that the details of the virtual rotor radius r, the virtual winding representative position (angle) θ of the k-th winding rmck (k = 1, 2,..., Nw), and the calculation formula for the eccentricity will be described later.

[0076] Furthermore, the memory 380 stores measurement data (in this example, the terminal voltage v of the k-th winding measured by the voltage-current measurement unit 330 uk , v vk , v wk winding current i uk , i vk , i wk (k = 1, 2,..., Nw)), the position θ acquired from the motor position sensor 116, and the dc-axis voltage v of the k-th winding coordinate-converted therefrom re , qc-axis voltage v dck , dc-axis current i qck , qc-axis current i dck, qc-axis current i qck , (k = 1, 2, …, Nw), and the eccentricity error angle Δθ of each winding calculated from motor constants and measurement data rek , Δθ rek tanΔθ calculated from rmk (k = 1, 2, …, Nw) is temporarily stored, and when the eccentricity is calculated, it functions as a storage device for storing the eccentricity

[0077] The input / output interface 390 inputs various measurement data and outputs it to the eccentricity display device 350 and the abnormality warning device 360. Further, the input / output interface 390 is connected to the upper control device 210, and it is possible to transmit and receive necessary information to and from the upper control device 210

[0078] Incidentally, the upper control device 210 can also be configured by a computer. In this case, the upper control device 210 and the eccentricity calculation device 300 may be configured by the same computer or by separate computers

[0079] <First Embodiment of Eccentricity Calculation Device and Method for Rotating Electric Machine> The processor 370 acquires during current control in the eccentricity calculation mode of the motor and stores in the memory 380 the terminal voltage v of the k-th winding uk , v vk , v wk , winding current i uk , i vk , i wk (k = 1, 2, …, Nw), the position θ acquired from the motor position sensor 116 re , and the dc-axis voltage v of the k-th winding coordinate-converted therefrom dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qck , (k = 1, 2, …, Nw), the motor constants stored in advance in the memory 380, and the calculation formula for the eccentricity, and uses them to calculate one or more of the eccentricity, the eccentricity error angle Δθ rek , and the value corresponding to the eccentricity error angle (the value of tanΔθ rmk described later). The calculated eccentricity, eccentricity error angle Δθ rek, and a value corresponding to the eccentricity error angle (tanΔθ described later rmk value) of any one or more of them are output to the eccentricity amount display device 350 and the abnormality warning device 360.

[0080] The terminal voltage v of the k-th winding uk , v vk , v wk is converted by the coordinate conversion unit 340 into values v in the dc-qc coordinates dck , v qck . The conversion formula is as follows.

[0081]

Equation

[0082] Also, the winding current i of the k-th winding uk , i vk , i wk is converted by the coordinate conversion unit 340 into values i in the qc coordinates dck , i qck . The conversion formula is as follows.

[0083]

Equation

[0084] Next, a method for calculating the amount of eccentricity will be described.

[0085] When the rotor of the motor is eccentric, the control d - q - c coordinates grasped by the control device deviate from the actual d - q coordinates compared to the case without eccentricity.

[0086] To explain this, Fig. 6 shows an example of a 4 - pole motor in which two sets of windings, the first winding (windings U1, V1, W1) and the second winding (windings U2, V2, W2), are arranged at intervals of π respectively.

[0087] In the case of no eccentricity in Fig. 6(A), the d - c axis grasped in control coincides with the d - axis which is the N - pole position of the rotor. That is, the values of the d - q - c coordinates and the actual d - q coordinates are the same.

[0088] In the case of eccentricity in Fig. 6(B), since the position of the rotor changes with eccentricity compared to before eccentricity, the d - c axis grasped in control deviates from the actual d - axis which is the N - pole position of the rotor. Therefore, the d - q - c coordinates and the actual d - q coordinates deviate. This deviation angle will be called the 'eccentric error angle'.

[0089] In the case of an electric motor with each phase winding of the Nw group, if it is eccentric, the dc-qc coordinates of the first winding and the actual d-q coordinates are shifted by Δθre1, the dc-qc coordinates of the second winding and the actual d-q coordinates are shifted by Δθ re2 shift, …, the dc-qc coordinates of the kth winding and the actual d-q coordinates are shifted by Δθ rek shift, …, the dc-qc coordinates of the Nwth winding and the actual d-q coordinates are shifted by Δθ reNw shift.

[0090] The basic idea of the eccentricity calculation method of the present invention is to measure or analyze the v dck , v qck , i dck , i qck of each winding of the electric motor, thereby calculating the above eccentricity error angles Δθ re1 , Δθ re2 , …, Δθ rek , …, Δθ reNw and obtaining the eccentricity from the results.

[0091] The outline of the procedure is shown below.

[0092] (1) Using the following-described arithmetic expression (the first arithmetic expression) for calculating the eccentricity error angle, as pre-measurement data or pre-analysis data for calculating the eccentricity, for a certain eccentricity (a1, a2) of the electric motor and the dc-axis voltage v of each winding under a certain operating condition dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qck , calculate the eccentricity error angle Δθ of the kth winding rek (k = 1, 2, …, Nw), and obtain tanΔθ rmk (k = 1, 2, …, Nw) from these and the number of pole pairs p of the electric motor. Then, obtain the two constants of the arithmetic expression (the second arithmetic expression) that associates tanΔθ rmk with the eccentricity (a1, a2). The constants are the virtual rotor radius r of the following-described geometric model of eccentricity and the virtual winding representative position (angle) θ rmck (k = 1, 2, …, Nw).

[0093] (2) To obtain any eccentricity amounts (a1’, a2’) of the motor, under the same operating conditions as in (1), the dc-axis voltage v of each winding at the eccentricity amount (a1’, a2’) to be obtained dck ’ , qc-axis voltage v qck ’ , dc-axis current i dck ’ , qc-axis current i qck ’ From these, the eccentricity error angle Δθ of each winding rek ’ is calculated, and from these and the number of pole pairs p of the motor, tanΔθ rmk ’ (k = 1, 2, …, Nw) is obtained. And if it is the same operating condition as the pre-measurement data or pre-analysis data in (1), the two constants of the formula associating the eccentricity error angle and the eccentricity amount will be approximately the same value regardless of the eccentricity amount (it may be regarded as approximately the same value). Based on the novel principle first discovered in the present invention, the eccentricity amounts (a1’, a2’) are calculated.

[0094] Hereinafter, the method for calculating the eccentricity amount will be described in detail. [Method for obtaining tanΔθ of the k-th winding from electrical quantities rmk (k = 1, 2, …, Nw)] Fig. 7 is a diagram showing a situation where the d-q coordinates and the dc-qc coordinates are shifted by Δθ re only.

[0095] In Non-Patent Document 1 shown below, the equation of the estimated rotation coordinates γ-δ coordinates in this situation has been derived.

[0096] [Non-Patent Document 1] "Sensorless Control of a Salient-Pole Permanent-Magnet Synchronous Motor Based on the Extended Induced Voltage Model", Transactions of the Institute of Electrical Engineers of Japan, Section D, Vol. 122, No. 12, 2002

[0097] In the present embodiment, the method for calculating the eccentricity amount will be described with reference to the voltage equation of this estimated rotation coordinates γ-δ coordinates.

[0098] For the sake of explanation, the estimated rotation coordinates γ-δ coordinates are changed to be described in the dc-qc coordinates grasped by the control device. Also, as shown in FIG. 1 of Non-Patent Document 1, if the estimated γ-δ coordinates are defined as the angle advanced in the mathematical positive rotation direction (counterclockwise) by Δθ re with respect to the actual d-q coordinates, the equation of the γ-δ coordinates of the extended induced voltage model in Non-Patent Document 1 is re Since it is correct to reverse the sign of Δθ, this is also changed to the correct equation. The following equation shows the equation of the dc-qc coordinates of the k-th winding (k = 1, 2,..., Nw) grasped by the control device.

[0099]

Equation

[0100] P: Differential operator i dk : Actual d-axis current of the k-th winding (k = 1, 2, …, Nw) i qk : Actual q-axis current of the k-th winding (k = 1, 2, …, Nw) ω re : Angular velocity in electrical angle = 2πf, where f is the power supply frequency Δθ rek : Eccentric error angle of the k-th winding (Deviation angle (electrical angle) between dc-qc coordinates and d-q coordinates, k = 1, 2, …, Nw) From Equation (3), the eccentric error angle Δθ of the k-th winding corresponding to a certain eccentricity amount is calculated using the following equation rek (k = 1, 2, …, Nw).

[0101]

Equation

[0102]

Equation

[0103] Based on the above principle, the tanΔθ of the k-th winding rmk (k = 1, 2, …, Nw) can be calculated. [The relationship between tanΔθ rm derived from the geometric model of eccentricity and the eccentricity (a1, a2)]

[0104] In FIG. 8, the rotor 110b of the motor 110 without eccentricity is shown by a dashed line, and the rotor 110b of the motor 110 with eccentricity by the eccentricity (a1, a2) is shown by a solid line.

[0105] Also, in FIG. 8, when there is no eccentricity, the rotor center (origin) is O, the radius of the rotor 110b is r, and the circumferential angle of the rotor 110b without eccentricity at a certain position is θ rm , and for this r, θ rm , the circumferential position of the rotor 110b without eccentricity corresponding to them is P0, the position obtained by translating P0 by the eccentricity (a1, a2) is P1, and the angle formed by the line segment O - P0 and the line segment O - P1 is Δθ rm is defined as such.

[0106] Let the complex number corresponding to P0 be z0 = r(cosθ rm + j sinθ rm ), and the complex number corresponding to P1 be z1 = (a1 + r cosθ rm ) + j(a2 + r sinθ rm ). When z0 is divided by z1, the following equation is obtained.

[0107]

Equation

[0108]

Equation

[0109] [tanΔθ obtained from electrical quantities rmk and tanΔθ of the eccentricity geometric model rm Association] tanΔθ of Equation (5) obtained from electrical quantities rmk and tanΔθ of Equation (7) of the eccentricity geometric model rm If they can be associated, the eccentricity amounts (a1, a2) can be obtained from the electrical quantities.

[0110] For this purpose, regarding the value of θ on the right side of Equation (7) of the eccentricity geometric model rm it is considered using Figure 9 which combines Figure 2 showing the winding arrangement of the motor etc. and Figure 8 of the eccentricity geometric model.

[0111] The right side of Equation (7) of the eccentricity geometric model is an equation for obtaining the value of tanΔθ rm at a certain (arbitrary) circumferential position θ rm On the other hand, since tanΔθ of Equation (5) obtained from electrical quantities rmk is obtained from the voltage and current of the k-th winding, when associating tanΔθ of Equation (5) rmk with tanΔθ on the left side of Equation (7) rm the θ on the right side of the corresponding Equation (7) rm may be considered to be the circumferential position θ rmck of the k-th winding.

[0112] Here, since the motor has a polyphase winding, the k-th winding is spatially distributed within a certain angular range as shown in Figure 9, but since tanΔθ rmk is calculated as one value, the circumferential position θ rmck of the k-th winding may be considered as one representative circumferential position representing the angular range of the spatially distributed k-th winding. The calculation method of θ rmck will be described later.

[0113] Also, as described above, the k - 1-th winding or the k + 1-th winding adjacent to the k-th winding of the motor has a representative circumferential position shifted from that of the k-th winding by an interval of 2π / Nw.

[0114] When reflecting the above, tanΔθ in Expression (5) obtained from electrical quantities rmk is associated with the left side of Expression (7) of the eccentricity geometric model, Expression (7) may be as follows.

[0115] [Number] θ rmc1 is the value (constant) of the representative circumferential direction position of the first winding

[0116] [Calculation of virtual rotor radius r and virtual winding representative position θ of each winding rmck Using Expression (5) and Expression (8), the virtual rotor radius r and the virtual winding representative position θ rmck can be determined as follows.

[0117] For a certain amount of eccentricity (a1, a2), tanΔθ of the k-th winding under a certain operating condition rmk (k = 1, 2,..., Nw) is obtained from Expression (5). Note that Δθ on the right side of Expression (5) rek is obtained by Expression (4).

[0118] Next, when substituting the obtained tanΔθ rmk into the left side of Expression (8), Nw equations in which r and θ rmck on the right side of Expression (8) are unknowns are obtained.

[0119] By solving these Nw equations simultaneously for r and θ rmck r and θ rmck can be obtained. However, since it is considered difficult in reality to solve a system of equations including sin and cos, r and θ rmck such that all Nw expressions hold may be obtained by a numerical analysis method. Various numerical analysis methods can be considered in this case. For example, r and θ rmck for which Δ shown by the following expression is minimized can be obtained by the least squares method of searching.

[0120] [Number] ​ Since the obtained r varies depending on the operating conditions, it is different from the actual rotor radius, and thus it will be referred to as the "virtual rotor radius".

[0121] Also, θ rmck As described above, actually, the k-th winding is not at a single point position (angle) but is spatially distributed. However, since θ rmck calculated based on Equation (5) and Equation (8) is calculated as a single-point value, θ rmck will be referred to as the "virtual winding representative position".

[0122] Here, it has been newly discovered that "under the same operating conditions, the virtual rotor radius r and the virtual winding representative position θ rmck are substantially equal regardless of the eccentricity. Although the reason is unclear, even when changing the physical size of the motor, the number of sets of UVW phase windings, the number of poles, the coil arrangement, the speed, the current vector, and the type of motor (not only synchronous motors but also induction motors), it has been confirmed that "under the same operating conditions, the virtual rotor radius r and the virtual winding representative position θ rmck are substantially equal", and thus it is believed to be a universal principle.

[0123] By utilizing this newly discovered principle, the number of eccentricities to be set in advance under a certain operating condition can be reduced (as will be explained in the sixth embodiment below, when Nw = 2, in order to obtain the virtual rotor radius and the virtual winding representative position, it is necessary to measure the voltage and current with two eccentricities in advance. When Nw ≠ 2, it is only necessary to measure the voltage and current with one eccentricity). Compared with the method of Patent Document 1, the time required to prepare for calculating the eccentricity can be shortened. Also, since the preparation time can be shortened, r and θ rmck under various operating conditions at the motor sales destination can be obtained in advance, and it becomes realistically possible to calculate the eccentricity at the motor sales destination.

[0124] [Calculation of Arbitrary Eccentricities (a1’, a2’)] To obtain arbitrary eccentricities (a1’, a2’) of the motor, r and θ rmckv of each winding under the same operating conditions as when obtained dck ’ 、v qck ’ 、i dck ’ 、i qck ’ is obtained by measurement or analysis. Next, the eccentricity error angle Δθ of the k-th winding rek ’ is set as Δθ on the left side of Equation (4) rek and Δθ rek ’ is substituted with v on the right side of Equation (4) dck 、v qck 、i dck 、i qck 、v dck ’ 、v qck ’ 、i dck ’ 、i qck ’ respectively, and Δθ rek ’ is calculated. Next, tanΔθ of the k-th winding rmk ’ (k = 1, 2,..., Nw) is set as tanΔθ on the left side of Equation (5) rmk and tanΔθ rmk ’ is substituted with the calculated Δθ rek ’ into Δθ on the right side of Equation (5) rek to calculate tanΔθ rmk ’ (k = 1, 2,..., Nw). Then, tanΔθ rmk ’ is substituted into tanΔθ on the left side of Equation (8) rmk and the values of r and θ on the right side of Equation (8) rmck are substituted with the values obtained in the case of the eccentricity (a1, a2) in advance. With (a1, a2) on the right side of Equation (8) set as an arbitrary eccentricity (a1’, a2’), Nw equations with (a1’, a2’) as unknowns are created, and the eccentricity can be calculated by solving these equations. Also, similar to the case when r and θ rmck are obtained, the eccentricity (a1’, a2’) that satisfies the Nw equations can also be obtained by the least squares method.

[0125] [Method for Calculating Eccentricity of Rotating Electrical Machine] FIG. 10 is a flowchart showing an embodiment of a method for calculating the eccentricity of a rotating electrical machine, and the eccentricity calculation device is executed by the eccentricity calculation device of the rotating electrical machine shown in FIG. 1 or FIG. 5.

[0126] In FIG. 10, the eccentricity calculation mode is selected in step S1. The selection of the eccentricity calculation mode is performed in the mode selection unit 212 of FIG. 1. The selection can be made, for example, by an operator operating a touch panel (not shown) provided in the mode selection unit 212.

[0127] When the eccentricity calculation mode is selected, in step S2, the host controller 210 outputs a switching signal M to the dc-qc axis current command calculation unit 216 so as to be a dc-qc axis current command for the eccentricity calculation mode. dq * to output.

[0128] In step S3, the dc-qc axis current command calculation unit 216 commands i dc * = 0, i qc * = 0 to stop the motor 110.

[0129] In step S4, the host controller 210 outputs a brake control command Bc to the brake control unit 172 to open or close the brake 170, and opens or closes the brake 170. * to output and open or close the brake 170.

[0130] In step S5, the dc-qc axis current command calculation unit 216 outputs a dc axis current command i dc * and a qc axis current command i qc * for the eccentricity calculation mode (see FIG. 4(A)).

[0131] i dc * and i qc *is, similar to the normal operation mode of FIG. 4(B), the dc-axis current command i dc * may be commanded to be, for example, 0, or may be commanded to achieve maximum torque, maximum efficiency, and power factor = 1. i qc * is calculated and commanded from, for example, the torque equation of the motor 110 based on the torque command T * . When i dc * is commanded to be 0, the value of the current vector can be minimized, so in the calculation of the eccentricity amount, the influence of the voltage drop due to resistance can be reduced. Also, if a command corresponding to various operating conditions at the motor sales destination is given, the eccentricity amount can be calculated without stopping the customer's operation for the calculation of the eccentricity amount.

[0132] In step S6, the processor 370 (FIG. 4) of the eccentricity amount calculation device obtains the dc-axis voltage v dck ’ of the k-th winding, the qc-axis voltage v qck ’ of the k-th winding, the dc-axis current i dck ’ of the k-th winding, the qc-axis current i qck ’ (k = 1, 2,..., Nw) after the command in step S5 and stores them in the memory 380.

[0133] In step S7, the processor 370 uses these stored values, the motor constants (the phase resistance R a of the motor, the d-axis inductance L d of the motor, the q-axis inductance L q ) stored in advance in the memory 380, and the eccentricity amount calculation formula (Equation (4). However, Δθ rek on the left side is set to Δθ rek ’ , and v dck on the right side, v qck , i dck , i qck are respectively replaced with v dck ’ , v qck ’ , i dck ’ , i qck ’(4) is calculated based on the above equation, and the eccentricity error angle Δθ of the kth winding is obtained. rek ’ (k=1, 2, ..., Nw) and tan Δθ on the left side of equation (5) rmk tan Δθ rmk ’ Then, Δθ on the right side rek to Δθ rek ’ Substituting the above, we get tan Δθ of the kth winding. rmk ’ (k=1, 2, ..., Nw) is found and stored in memory 380. Here, equations (4) and (5) are a first calculation formula for calculating the eccentricity error angle, and are part of the calculation formula for the amount of eccentricity stored in memory 380. Furthermore, when equation (5) is generalized to a motor having a different number of pole pairs from motor 110, the number of pole pairs p in equation (5) is one of the motor constants determined by the motor.

[0134] And tan Δθ rmk ’ tan Δθ on the left side of equation (8) rmk Substituting r and θ on the right hand side of equation (8), rmck The values ​​previously found for the amount of eccentricity (a1, a2) are substituted into the value of (a1, a2) and (a1, a2) on the right side of equation (8) is set to an arbitrary amount of eccentricity (a1', a2'), and the amount of eccentricity (a1', a2') is calculated by solving Nw equations with the amount of eccentricity (a1', a2') as the unknown. Since there are two unknowns, when Nw (≧2) is 3 or more, the amount of eccentricity (a1', a2') can be calculated by using two of the equations. The amount of eccentricity (a1', a2') that satisfies the Nw equations may also be found by the least squares method. The amount of eccentricity (a1', a2') found, the eccentricity error angle Δθ rek ’ and the value corresponding to the eccentricity error angle (tan Δθ rmk ’ The eccentricity amount (a1', a2'), the eccentricity error angle Δθ rek ’ and the value corresponding to the eccentricity error angle (tan Δθ rmk ’Output any one or more of the values) to the eccentricity display device 350 or the abnormality warning device 360 to end the eccentricity calculation mode.

[0135] To verify the above validity, based on the flowchart of FIG. 10, the eccentricity calculation mode was verified by magnetic field analysis.

[0136] The motor 110 was a 6-pole 9-slot three-phase permanent magnet synchronous motor. FIG. 11 shows the mechanical dimension diagram of the motor 110. Also, FIG. 12 shows the coil arrangement and wiring diagram. The symbol next to the coil symbol indicates that when a positive current is flowing, the current flows in the direction toward the paper surface, and when a negative current is flowing, the current flows from the paper surface toward the front. Also, in the case of a negative symbol, it indicates that when a positive current is flowing, the current flows in the direction from the paper surface toward the front, and when a negative current is flowing, the current flows in the direction toward the paper surface. The stator winding is wound intensively around the teeth with one winding, and the three windings of the same phase are connected in series. Also, the magnet is an arc-shaped surface magnet type.

[0137] In the eccentricity calculation mode of this verification, the brake 170 is opened to keep the rotational speed constant, and the dc-axis current command i dc * , qc-axis current command i qc * are kept constant, and the case of a steady state where the average currents of the dc-axis current i dck , qc-axis current i qck of the k-th winding (k = 1, 2,..., Nw) become constant is considered.

[0138] In this case, in Equation (4), i dck , i qck , i dk , i qk can be approximated to 0 for the time derivative terms. Also, the time derivative of Δθ rek is the rotational speed with respect to the d-q coordinates of the dc-qc coordinates. However, when the air gap between the stator and the rotor is sufficiently small with respect to the outermost diameter of the rotor (for example, when the air gap is less than 1 / 50 of the rotor outer diameter), the time derivative of Δθ rek can be approximated to almost 0. Also, generally, the d-axis inductance L dSince it has a value of several mH to several tens of mH, the term including the time derivative of Δθ rek can be approximated more closely to 0. Therefore, Equation (4) can be approximated by the following equation.

[0139]

Equation

[0140] First, as pre-analysis data for calculating the eccentricity amount, when the motor 110 is operated with the eccentricity amounts (a1, a2) = (0.0 mm, -0.5 mm) set in advance, the v dck of the k-th winding, v qck , i dck , i qck (k = 1, 2, 3), and the electrical angular velocity ω re are shown in [Table 1].

[0141]

Table 1

[0142]

Table 2

[0143]

Equation

[0144] [Non-Patent Document 2] "Method for Measuring d-q Axis Equivalent Circuit Constants of PM Motors", Transactions of the Institute of Electrical Engineers of Japan, Section D, Vol. 113, No. 11, 1993 L in Equation (3) qk As described in the explanation of L qk requires a value without eccentricity. However, from the theorem that the full-circumference average of tanΔθ rm of each winding described later becomes 0, v dc without eccentricity, v qc i dc i qc Let v dck v qck i dck i qck ω re (k = 1, 2, 3) of the k-th winding at the time of eccentricity can be obtained from them.

[0145] Therefore, the q-axis inductance L q may be calculated by Equation (11) without being stored as a motor constant in the memory 380.

[0146] [Table 1], [Table 2] and Equation (10), the eccentricity error angle Δθ rek (k = 1, 2, 3) of the k-th winding is calculated, and the results of obtaining tanΔθ rmk using these and Equation (5) are shown in [Table 3].

[0147]

Table 3

[0148] Also, the electrical angular velocity ω re or the power supply frequency f in [Table 1] can be stored in the memory 380.

[0149] From the results of [Table 3], the virtual rotor radius r and the virtual winding representative position θ rmckThe value of is calculated using the least squares method so that Δ in equation (9) is minimized. The results are shown in [Table 4]. [Table 4] also lists the value of the sum of squares of the error Δ.

[0150] [Table 4] Figure 13 shows the geometric model of eccentricity, with the eccentricity (a1, a2) = (0.0 mm, -0.5 mm) in equation (7), and applying r in [Table 4] to obtain θ rm When tanΔθ is changed rm The solid line indicates (θ rmc1 , tan Δθ rm1 ), (θ rmc2 , tan Δθ rm2 ), (θ rmc3 , tan Δθ rm3 ) is a diagram showing three plot points.

[0151] As can be seen from the values ​​of the squared error in Figure 13 and [Table 4], (θ rmc1 , tan Δθ rm1 ), (θ rmc2 , tan Δθ rm2 ), (θ rmc3 , tan Δθ rm3 The plotted points of all the plots were calculated using equation (7) (θ rm , tan Δθ rm ) on the solid curve, and the calculated virtual rotor radius r and the virtual winding representative position θ rmck can be said to be reasonable.

[0152] By the way, this r, θ rmck The values ​​of (a1, a2) were applied to the simultaneous equation of (5) and (8) to obtain the eccentricity (a1, a2). The results are shown in [Table 5].

[0153] [Table 5] Set r and θ so that the eccentricity (a1, a2) = (0.0mm, -0.5mm). rmckNaturally, since the identified value is being used, it can be said that the absolute value of the difference between the calculated eccentricity and the set eccentricity is small and they match well.

[0154] Next, when taking arbitrary eccentricities as (a1’, a2’) = (-0.3 mm, -0.4 mm), (0.6 mm, -0.7 mm), (0.9 mm, 0.2 mm), (0.0 mm, 0.0 mm), the r and θ in [Table 4] rmck under the same operating conditions (ω re , i dck , i qck being the same), when the motor is operated, the average values of v dck ’ , v qck ’ , i dck ’ , i qck ’ for the k-th winding (k = 1, 2, 3), and the electrical angular velocity ω re are shown in [Table 6].

[0155]

Table 6

[0156]

Table 7

[0157]

Table 8

[0158] Also, for each eccentricity value (a1’,a2’) = (-0.3mm, -0.4mm), (0.6mm, -0.7mm), (0.9mm, 0.2mm), (0.0mm, 0.0mm), the results of (θ rmc1 , tanΔθ rm1 ’ ), (θ rmc2 , tanΔθ rm2 ’ ), (θ rmc3 , tanΔθ rm3 ’ ) are shown as plotted points in Figures 14(A), 14(B), 14(C), and 14(D). Furthermore, with the eccentricity values (a1’,a2’) = (-0.3mm, -0.4mm), (0.6mm, -0.7mm), (0.9mm, 0.2mm), (0.0mm, 0.0mm) in Equation (7) and applying the r in [Table 4], the results of tanΔθ rm when θ rm is changed are shown as solid lines in Figures 14(A), 14(B), 14(C), and 14(D).

[0159] For (θ in Figure 14rmc1 , tanΔθ rm1 ’ ), (θ rmc2 , tanΔθ rm2 ’ ), (θ rmc3 , tanΔθ rm3 ’ ) Any of the plotted points of (θ rm , tanΔθ rm ) is on the solid line of (θ rmck calculated by Equation (7). The virtual rotor radius r and the virtual winding representative position θ rmck used for calculating the eccentricity (a1’, a2’) are values obtained by setting the eccentricity (a1, a2) = (0.0 mm, -0.5 mm) in advance. However, it can be said that there is no problem even if different eccentricities (a1’, a2’) are used with the same r and θ

[0160] According to this example, under the same operating conditions, it is certain that the validity of the principle that the virtual rotor radius r and the virtual winding representative position θ rmck are almost equal regardless of the eccentricity has been verified. Also, in this example, when obtaining r and θ rmck , only one eccentricity was set. However, multiple eccentricities can be set to obtain r and θ rmck respectively, and the finally determined r and θ rmck can be, for example, the average values of these. Note that, as will be described later, the validity is similarly verified for other motors.

[0161] Also, as is clear from FIGS. 13 and 14, the larger the vector sum of the eccentricities, the larger the absolute value of the value of tanΔθ rmk (k = 1, 2, 3). Also, when Δθ rmk ≒0, there is a relationship of tanΔθ rmk ≒Δθ rmk = Δθ rek / p. Utilizing this, the abnormality warning device 360 in FIG. 1 not only inputs the calculated eccentricity and compares it with the threshold eccentricity serving as the abnormality determination criterion, but also the eccentricity error angle Δθ rek (k = 1, 2, 3) and the value corresponding to the eccentricity error angle (for example, tanΔθ rmkEnter the value of (k = 1, 2, 3)) to obtain the eccentric error angle Δθ of the threshold value serving as the abnormality determination criterion rek or the value corresponding to the eccentric error angle (for example, tanΔθ rmk (k = 1, 2, 3)) and compare them to issue an alarm if necessary.

[0162] After the eccentricity calculation mode ends, the mode selection unit 212 selects the normal operation mode and performs the normal operation of the motor 110.

[0163] FIG. 15 is a flowchart showing a specific processing procedure by the control device of the rotary electric machine when the normal operation mode is selected.

[0164] In FIG. 15, at step S11, the mode selection unit 212 (FIG. 1) selects the normal operation mode. When the normal operation mode is selected, at step S12, the host control device 210 outputs a brake control command Bc to open the brake 170 by the brake control unit 172, and operates the brake 170 to open.

[0165] At step S13, the host control device 210 outputs a speed command N * and outputs a switching signal M dq * to the dc-qc axis current command calculation unit 216 so as to be a dc-qc axis current command for the normal operation mode.

[0166] At step S14, the dc-qc axis current command calculation unit 216 outputs a dc axis current command i * in response to the torque command T dc * and a qc axis current command i qc * to operate the motor 110.

[0167] To summarize the above, the eccentricity calculation device of the rotary electric machine of the present invention has the following advantages compared with the known technology, and it is possible to obtain an eccentricity calculation device and method superior to the known technology.

[0168] 1. For eccentricity measurement, the number of eccentricities preset under certain operating conditions is small, and the preparation time is shorter compared to the method of Patent Document 1.

[0169] 2. Since the time required is short, r and θ under various operating conditions at the motor sales destination rmck can be obtained in advance, making it realistically possible to calculate the eccentricity at the motor sales destination.

[0170] 3. The eccentricity can be calculated with high precision by a control device that drives the motor.

[0171] Furthermore, if added, there are the following differences from the known technology.

[0172] The method of Patent Document 1 can be said to be a method of obtaining the eccentricity by directly associating the eccentricity with the voltage. The method of Patent Document 2 can be said to be a method of associating the waveform of the three-phase to two-phase converted current with abnormalities (such as eccentricity).

[0173] On the other hand, the present invention focuses on the fact that as the eccentricity changes, the eccentricity error angle between the dc-qc axis grasped by the control device and the actual dq axis changes, and as a result, the voltage of the dc-qc axis of each winding grasped by the control device changes. The voltage, current, and motor constant of the dc-qc axis of each winding grasped by the control device are applied to the first arithmetic expression (Expression (4), Expression (5), or (Expression (10), Expression (5))) to obtain the eccentricity error angle, and the eccentricity is obtained from the second arithmetic expression (Expression (7) or Expression (8)) showing the relationship between the obtained eccentricity error angle and the eccentricity.

[0174] First, in order to calculate the eccentricity, it is different from Patent Document 1 in that the constants of the rotating electrical machine are based on a new calculation formula for the eccentricity described in the formula. The method of Patent Document 1 is based on the basic idea that if the design specifications are determined and the measurement conditions are the same, the relationship between the winding terminal voltage or winding current and the eccentricity ratio is the same. The relationship between the terminal voltage or winding current of the winding with known positional relationship and the eccentricity ratio (eccentricity) is graphed and obtained. When obtaining an arbitrary eccentricity ratio (eccentricity), the eccentricity ratio (eccentricity) is obtained from the terminal voltage or winding current based on this graph. In Patent Document 1, since the eccentricity ratio (eccentricity) is obtained from the graph, there are no constituent elements of the "calculation formula for eccentricity". Even if there is a calculation formula, it is considered to be based on an approximate formula obtained from the graph of voltage or current and eccentricity ratio (eccentricity) obtained by experiment or analysis, and the "constants of the rotating electrical machine" are not considered to appear in the formula of the calculation formula. Also, in the case of a rotating electrical machine with different design specifications, that is, different "constants of the rotating electrical machine", different graphs need to be prepared accordingly. On the other hand, in the present invention, when the design specifications of the rotating electrical machine are different, the difference appears in the "constants of the rotating electrical machine", so it can be calculated with exactly the same "calculation formula for eccentricity" even if the design specifications are different. Thus, the present invention is completely different from Patent Document 1. Also, Patent Document 2 does not have the constituent elements of the calculation formula for eccentricity in the first place.

[0175] Also, the calculation of the eccentricity using the values obtained by coordinate transformation of the voltage and current is different from Patent Document 1. The method of Patent Document 1 only obtains the relationship between the effective value of voltage or current (or the value obtained by rectifying alternating current with a rectifier) and the amount of eccentricity, and there is no description or suggestion regarding the relationship between the values obtained by coordinate transformation of voltage and current and the eccentricity (amount of eccentricity). Embodiment 1, which describes the main content of Patent Document 1, takes a capacitor motor as an example. Since this is not a motor with vector control, it is presumed that there was no motivation to perform coordinate transformation on voltage or current. In Embodiment 5 of Patent Document 1, as a derivative form of Embodiment 1, a three-phase AC motor is taken as an example. However, there is also no description of vector control here, and only an example of operating as a generator by external drive is shown. Therefore, in the method for calculating the amount of eccentricity in Patent Document 1, it is considered that there was no idea of calculating the amount of eccentricity of a motor with vector control (coordinate transformation of voltage and current and control with the state variables after coordinate transformation). Thus, the present invention and Patent Document 1 are completely different in their ideas. Further, Patent Document 2 uses the current after coordinate transformation but does not use the voltage after coordinate transformation, which is different from the present invention that also includes voltage as a constituent element. Furthermore, it is different from Patent Document 2 in that it can calculate a highly accurate amount of eccentricity. In Patent Document 2, as described above, a method for obtaining a specific amount of eccentricity is not disclosed and there is no suggestion either.

[0176] Furthermore, it is different from both Patent Document 1 and Patent Document 2 in that it goes through the process of obtaining the eccentricity error angle. The concept of the eccentricity error angle itself is newly proposed by the present invention, and it is firmly believed to have novelty. Also, since the eccentricity error angle can only be derived with the concept of coordinate transformation, it is firmly believed that it will never appear in Patent Document 1 which does not have the concept of coordinate transformation. Although Patent Document 2 has the concept of coordinate transformation, it only focuses on current and does not focus on voltage. As can be seen from Equation (4) and Equation (16) of Embodiment 2 described later, since the equation for obtaining the eccentricity error angle has a voltage term, it can be asserted that the concept of the eccentricity error angle will never appear in Patent Document 2 either.

[0177] Second, as described above, in Equation (8) showing the relationship between the eccentricity error angle and the amount of eccentricity, the "virtual rotor radius r, virtual winding representative position θ" rmckIt also completely differs from Patent Document 1 and Patent Document 2 in that it utilizes the newly discovered principle that "under the same operating conditions, it is almost equal regardless of the amount of eccentricity". Since there is no concept corresponding to this principle in Patent Document 1, it is necessary to measure the voltage and current in advance for a large number of cases of the amount of eccentricity. However, in the present invention, as described above, it is only necessary to measure the voltage and current in advance for a small number of cases of the amount of eccentricity.

[0178] Thirdly, it is also clearly different from the method of estimating eccentricity by focusing on the fact that when an abnormality (such as eccentricity) occurs, the frequency component of the current grasped by the control device changes as in Patent Document 2 (however, it cannot estimate the specific amount of eccentricity (a1, a2)). This is because the present invention does not focus on the frequency component of the current.

[0179] From the above, it is clear that both Patent Document 1 and Patent Document 2 are clearly different from the present invention. Therefore, even if they are combined, something similar to the present invention can never be created. I am convinced that the present invention is not something that can be easily conceived by those skilled in the art with ordinary knowledge in this field.

[0180] <Second Embodiment of the Eccentricity Amount Calculation Device and Method for a Rotating Electric Machine> In the first embodiment of the eccentricity amount calculation device and method for a rotating electric machine, in the calculation of the eccentricity error angle Δθ re the d-axis inductance L d and the q-axis inductance L q are used.

[0181] L d and L q In Non-Patent Document 2 which describes the measurement method of, for L d and L q under a certain operating condition, they are obtained from the values of the d-axis voltage and current, the q-axis current, the rotational angular velocity, and the motor constant. This test method can be relatively easily implemented for a small-capacity motor, but it is not always easy for a large-capacity machine.

[0182] Also, L d and L qIn another paper of the Institute of Electrical Engineers that described the measurement method, in order to make it easy to implement even for a large-capacity machine, L is obtained by a static test. d L q However, there are spatial harmonic effects in the motor due to its structure, whether large or small, and it is not easy to measure in a static test while fully considering that the values of L d L q change according to the position of the rotor as the order of the harmonics increases. As far as the inventor knows, there is no standardized measurement method for L d L q of the permanent magnet synchronous motor yet.

[0183] In such a situation, the method of using the values of L d L q in the first embodiment may cause a lot of hesitation for those skilled in the art.

[0184] In order to solve the above problems, first, a newly discovered theorem that the full-circumference average of tanΔθ in the formula (7) of the eccentricity geometric model is 0 is proved. From this theorem, it can be shown that the average value of the quantities of each winding of the eccentric motor is the same as that without eccentricity. Utilizing this, instead of obtaining the eccentricity error angle Δθ rm (k = 1, 2,..., Nw) for each k-th winding alone as in the first embodiment, a formula for obtaining Δθ rek (k = 1, 2,..., Nw) of the k-th winding from the voltage and current values of all the windings of the motor can be newly derived. This formula for Δθ rek (k = 1, 2,..., Nw) does not include the d-axis inductance L d and the q-axis inductance L q , and is insensitive to L d L q L rm .

[0185] [Theorem that the full-circumference average of tanΔθ rm is 0] The full-circumference average Ave.tanΔθ rm of tanΔθ represented by the formula (7) of the eccentricity geometric model is obtained by the following formula from the theorem of the average value of integration. Here, r is not only a constant value (true circle), but also a function r(θ rm of θ rm ).rm ) and generalized. However, r(θ rm + 2π) = r(θ rm ). Also, r’(θ rm ) represents the first-order derivative of r(θ rm ) at the circumferential position θ rm .

[0186]

Math

[0187]

Math

[0188]

Math

[0189] Furthermore, considering that when Δθ rm ≒ 0, tanΔθ rm ≒ Δθ rm , at each circumferential position θ rm , the eccentricity error angle Δθ rmEven if it occurs, the value averaged over the entire circumference means that it is equal to the case without eccentricity (shift angle = 0). Incidentally, Δθ rm ≒ 0 means that r(θ rm ) is for all θ rm at which the vector sum of the eccentricity amounts √(a1 2 + a2 2 ) is sufficiently large, which is a prerequisite for sufficient validity.

[0190] For the theorem that the average value of the above tanΔθ rm over the entire circumference becomes 0, even if an eccentricity error angle Δθ rm occurs at the circumferential position θ rm of each winding of the motor due to eccentricity, causing variations in the quantities (for example, dc-axis voltage v dc , qc-axis voltage v qc ) of each winding of the motor, the average value of these quantities is equal to the quantities in the case without eccentricity.

[0191] Therefore, the quantities of each winding of the motor in the case without eccentricity can be obtained as the average value of the quantities of each winding of the eccentric motor. And, an equation for calculating the eccentricity amount can be derived using this.

[0192] [Equation for calculating eccentricity amount using the theorem that the average value of tanΔθ rm over the entire circumference becomes 0] In the first embodiment, the eccentricity error angle Δθ rek was obtained using only the quantities in the dc-qc coordinates of the k-th winding (k = 1, 2,..., Nw). In the second embodiment, from the theorem that the average value of tanΔθ rm over the entire circumference becomes 0, by utilizing the fact that the quantities in the dc-qc coordinates in the case without eccentricity can be obtained from the quantities in the dc-qc coordinates of the k-th winding (k = 1, 2,..., Nw) with eccentricity, the eccentricity error angle Δθ rek 0 is obtained.

[0193] Here, FIG. 16 shows a situation where the dc-qc coordinates (for convenience, denoted as dck-qck coordinates) of the k-th winding (k = 1, 2,..., Nw) with eccentricity and the dc-qc coordinates in the case without eccentricity are shifted by Δθ rek 0. The dc-axis voltage v of the k-th winding (k = 1, 2,..., Nw)dck 、qc-axis voltage v qck 、dc-axis current i dck 、qc-axis current i qck 、phase resistance R ak The equations showing the relationships between these and the quantities in the case of no eccentricity are as follows.

[0194]

Equation

[0195] Here, v dck 、v qck but not v dck -R ak i dck 、v qck -R ak i qck is for the following reasons.

[0196] The eccentricity amount calculation method of the present invention utilizes the fact that the magnetic flux linkage number linked to the windings of the motor changes due to eccentricity, and as a result, the voltage and current of the motor change. On the other hand, R ak i dckSince it is independent of the magnetic flux linkage number inside the motor, by subtracting this, we obtain the voltage v related to the magnetic flux linkage number. dck -R ak i dck 、v qck -R ak i qck This is for obtaining v. dck -R ak i dck 、v qck -R ak i qck It will be obvious to those skilled in the art that v is the voltage related to the magnetic flux linkage number for all polyphase AC motors.

[0197] Therefore, it goes without saying that Equation (15) is also applicable to induction motors. Solving Equation (15) for cosΔθ rek0 、sinΔθ rek0 yields the following equation.

[0198]

Equation

[0199]

Equation

[0200]

Equation

[0201] [Number] θ rmc1 is the value of the representative circumferential direction position of the first winding (constant) The flowchart showing the second embodiment of the eccentricity calculation method of the rotating electric machine is the same as FIG. 10.

[0202] The difference from the first embodiment is only the calculation method of the eccentricity.

[0203] To verify the above validity, based on the flowchart of FIG. 10, the eccentricity calculation mode was verified by magnetic field analysis. The motor and operating conditions were the same as in the first embodiment.

[0204] As pre-analysis data for eccentricity calculation, when the motor was operated with the eccentricity (a1, a2) = (0.0 mm, -0.5 mm) set in advance, the v of the k-th winding dck , v qck , i dck , i qck (k = 1, 2, 3) average value, and the result of the electrical angular velocity ω re is the same as [Table 1]. The motor constants are also the same as [Table 2]. However, only the value of the phase resistance is used, and the value of the q-axis inductance is not used.

[0205] [From Table 1], [Table 2] and Equation (17), the eccentricity error angle Δθ of the k-th winding rek0 (k = 1, 2, 3) was calculated, and the result of obtaining tanΔθ rmk0 using Equation (18) is shown in [Table 9].

[0206] [Table 9] From the results of [Table 9], the values of the virtual rotor radius r and the virtual winding representative position θ rmck shown in Equation (19) are obtained by the least squares method so that Δ in the following equation is minimized.

[0207]

Number

[0208]

Table 10

[0209] As can be seen from the values of the sum of squared errors in Figure 17 and [Table 10], any of the plotted points of (θ rmc1 , tanΔθ rm10 ), (θ rmc2 , tanΔθ rm20 ), and (θ rmc3 , tanΔθ rm30 ) is on the curve of the solid line of (θ rm , tanΔθ rm ) obtained by equation (7), and it can be said that the calculated virtual rotor radius r and virtual winding representative position θ rmck are reasonable.

[0210] Incidentally, the results of obtaining the eccentricity amounts (a1, a2) by applying the values of this r and θ rmck to the equations obtained by simultaneously solving equations (18) and (19) are shown in [Table 11].

[0211]

Table 11

[0212] Next, when arbitrary eccentricities are set as (a1’, a2’) = (-0.3 mm, -0.4 mm), (0.6 mm, -0.7 mm), (0.9 mm, 0.2 mm), (0.0 mm, 0.0 mm), the r and θ in [Table 10] rmck are obtained under the same operating conditions (ω re , i dck , i qck is the same), and when the motor is operated, the average values of v dck ’ , v qck ’ , i dck ’ , i qck ’ for the k-th winding (k = 1, 2, 3), and the electrical angular velocity ω re are the same as those in [Table 6].

[0213] From [Table 6], [Table 10] and Equation (17), the eccentricity error angle Δθ rek0 ’ for the k-th winding (k = 1, 2, 3) is calculated by setting Δθ on the left side of Equation (17) rek0 as Δθ rek0 ’ , and substituting v dck , v qck , i dck , i qck with v dck ’ , v qck ’ , i dck ’ , i qck ’ respectively. Then, tanΔθ rmk0 ’ for the k-th winding is calculated by setting tanΔθ on the left side of Equation (18) rmk0 as tanΔθ rmk0 ’ , and substituting Δθ rek0 with Δθ rek0 ’ . The calculated results are shown in [Table 12].

[0214]

Table 12

[0215]

Table 13

[0216] Also, for each eccentricity (a1’, a2’) = (-0.3mm, -0.4mm), (0.6mm, -0.7mm), (0.9mm, 0.2mm), (0.0mm, 0.0mm), the results of (θ rmc1 , tanΔθ rm10 ’ ), (θ rmc2 , tanΔθ rm20 ’ ), (θ rmc3 , tanΔθ rm30 ’ ) are shown as plotted points in FIGS. 18(A), 18(B), 18(C), and 18(D). Furthermore, taking eccentricity (a1’, a2’) = (-0.3mm, -0.4mm), (0.6mm, -0.7mm), (0.9mm, 0.2mm), (0.0mm, 0.0mm) in Equation (7) and applying r and θ of [Table 10], the results of plotting tanΔθ rmck are shown as solid lines in FIGS. 18(A), 18(B), 18(C), and 18(D). rm

[0217] In FIG. 18, (θ rmc1 , tanΔθ rm10 ’ ), (θ​​rmc2 , tanΔθ rm20 ’ ), (θ rmc3 , tanΔθ rm30 ’ ) Any of the plotted points of (θ rm , tanΔθ rm ) is on the solid curve of (θ rmck calculated by Equation (7). The virtual rotor radius r and the virtual winding representative position θ

[0218] In this example, the motor constant only requires the value of the phase resistance R ak of each winding, and the values of the d-axis inductance Ld and the q-axis inductance L q are not required. It is an insensitive calculation method with respect to the values of L d , L q . That is, there is no need to worry about the values of L d , L q . Compared with Equation (4) of the first embodiment, the eccentric error angle Δθ rek0 can be obtained extremely easily and simply. It is emphasized that this is a special effect obtained by a newly discovered theorem that the overall average of tanΔθ rm becomes 0.

[0219] <Third Embodiment of Eccentricity Calculation Device and Method for Rotating Electrical Machinery> In the first and second embodiments, in the eccentricity calculation mode, the brake 170 is opened, the rotation speed is constant, and the dc-axis current command i dc * , the qc-axis current command i qc * are kept constant, and the average currents of the dc-axis current i dck and the qc-axis current i qck (k = 1, 2,..., Nw) of the k-th winding are constant in the steady state, and the dc-axis voltage v dck , the qc-axis voltage v qck , the dc-axis current i dck , the qc-axis current iqck The eccentricity was calculated from (k = 1, 2, …, Nw).

[0220] In the third embodiment, in the eccentricity calculation mode, the brake 170 is closed to lock the rotor, and the dc-axis current command i dc * and the qc-axis current command i qc * are controlled to be a steady alternating current, and the eccentricity is calculated from the AC effective values of the dc-axis current i dck , the qc-axis current i qck , the dc-axis voltage v dck , the qc-axis voltage v qck , the dc-axis current i dck , and the qc-axis current i qck when they are a steady alternating current.

[0221] The reason why the dc-axis current command i dc * and the qc-axis current command i qc * are set as a steady alternating current is that when the rotor is stationary and a steady direct current is commanded as the dc-axis current command i dc * and the qc-axis current command i qc * , the voltage related to the magnetic flux linkage of the motor winding becomes zero, and there is no voltage difference between the windings, so the eccentricity cannot be calculated. The dc-axis current command i dc * and the qc-axis current command i qc * do not have to be a steady alternating current, and any current command that generates a voltage related to the magnetic flux linkage of the motor winding is acceptable. For example, a step-shaped or ramp-shaped current command may be used. This is because a step-shaped dc-axis current command i dc * or qc-axis current command i qc * theoretically includes frequency components from 0 to infinity, and the corresponding dc-axis voltage command v dc * also includes such frequency components, and a voltage related to the magnetic flux linkage of the motor winding can be obtained even in the stationary state. Step-shaped or ramp-shaped current commands are easy to implement.

[0222] In addition, in the first and second embodiments, the stator winding of the motor was a six-pole nine-slot three-phase permanent magnet synchronous motor in which one winding was concentratedly wound around one tooth.

[0223] The motor of the third embodiment was a three-phase squirrel-cage induction motor with a distributed winding of 12 poles and 45 slots for the stator winding and 90 conductor bars for the rotor.

[0224] FIG. 19 is a diagram showing a cross-sectional view of the main part of the motor and its mechanical dimensions. FIG. 20 is a diagram showing a cross-sectional view of the main part of the motor, coil arrangement, and connection, and shows all the coil arrangements for only the U phase. For the V and W phases, only the start and end of the winding are shown. The stator windings connect three windings of the same phase in series.

[0225] The calculation of the eccentricity is performed using Equations (15) to (20) of the second embodiment, which can also be applied to induction motors.

[0226] First, as pre-analysis data for calculating the eccentricity, the effective values of the k-th winding, v qck , i dck , i qck (k = 1, 2, 3) and the power supply frequency f when the motor is operated with the eccentricity (a1, a2) = (0.0 mm, -0.5 mm) set in advance are shown in [Table 14].

[0227]

Table 14

[0228]

Table 15

[0229] [Table 16] From the results in [Table 16], the values of the virtual rotor radius r and the virtual winding representative position θ shown in Equation (19) rmck are obtained by the least squares method so that Δ in Equation (20) is minimized. The results are shown in [Table 17]. [Table 17] also shows the value of the sum of squared errors Δ.

[0230] [Table 17] Figure 21 shows the solid line of tanΔθ when the eccentricity (a1, a2) = (0.0 mm, -0.5 mm) in the geometric model of eccentricity in Equation (7) and the r in [Table 17] are applied and θ rm is changed, and three plot points of (θ rm , tanΔθ rmc1 ), (θ rm10 , tanΔθ rmc2 ), (θ rm20 , tanΔθ rmc3 ) are shown. rm30 )

[0231] As can be seen from the values of the sum of squared errors in Figure 21 and [Table 17], the solid line curve of (θ rmck , tanΔθ rm ) obtained with the identified values of r and θ rm coincides well with any of the plot points of (θ rmc1 , tanΔθ rm10 ), (θ rmc0 , tanΔθ rm20 ), (θ rmc3 , tanΔθ rm30 ). It can be said that the calculated r and the virtual winding representative position θ rmck are reasonable.

[0232] Incidentally, the results of obtaining the eccentricity (a1, a2) by applying the values of this r and θ rmck to the equations obtained by simultaneously solving Equation (18) and Equation (19) are shown in [Table 18].

[0233] [Table 18] Identify r and θ so that the set eccentric amounts (a1, a2) = (0.0 mm, -0.5 mm). rmck Naturally, since r and θ are identified, it can be said that the absolute value of the difference between the calculated eccentric amount and the set eccentric amount is small and they are in good agreement.

[0234] Next, when arbitrary eccentric amounts are (a1’, a2’) = (-0.3 mm, -0.4 mm), (0.6 mm, -0.7 mm), (0.9 mm, 0.2 mm), (0.0 mm, 0.0 mm), r and θ in [Table 17] rmck are obtained under the same operating conditions (f, i dck , i qck are the same), when the motor is operated, the v dck ’, v qck ’ , i dck ’ , i qck ’ (k = 1, 2, 3), ω re The results of are shown in [Table 19].

[0235]

Table 19

[0236]

Table 20

[0237]

Table 21

[0238] , tanΔθ rmc1 ), (θ rm10 ’ ), (θ rmc2 ), tanΔθ rm20 ’ ), (θ rmc3 ), tanΔθ rm30 ’ ) at each eccentricity value (a1’, a2’) = (-0.3 mm, -0.4 mm), (0.6 mm, -0.7 mm), (0.9 mm, 0.2 mm), (0.0 mm, 0.0 mm) are shown as plotted points in Figures 22(A), 22(B), 22(C), and 22(D). Furthermore, with the eccentricity values (a1’, a2’) = (-0.3 mm, -0.4 mm), (0.6 mm, -0.7 mm), (0.9 mm, 0.2 mm), (0.0 mm, 0.0 mm) in Equation (7), and applying the r in [Table 17], when θ rm is changed, the tanΔθ rmThe results shown are indicated by the solid lines in FIGS. 22(A), 22(B), 22(C), and 22(D).

[0239] For (θ in FIG. 22 rmc1 , tanΔθ rm10 ’ ), (θ rmc2 , tanΔθ rm20 ’ ), (θ rmc3 , tanΔθ rm30 ’ ), any of the plotted points is close to the curve of (θ rm , tanΔθ rm ) obtained by Equation (7), although there is a slight difference.

[0240] Comparing with the results of the first and second embodiments, it is considered that the large difference between the calculated value and the set value of the eccentricity is because distortion occurred in the dc-axis voltage and the qc-axis voltage in the winding where the distance from the rotor became close due to eccentricity. Since the rotors of the first and second embodiments are rotors in which arc-shaped magnets are arranged, it is considered that magnetic saturation hardly occurs due to the magnetic resistance of the magnets. However, since the rotor of the third embodiment has the electromagnetic steel sheet exposed, it is considered that magnetic saturation easily occurs. Also, it is considered that the magnetic resistance from the rotor center to the rotating surface is constant over the entire circumference for the rotors of the first and second embodiments, but for the rotor of the third embodiment, the presence and absence of conductor bars in the circumferential direction are alternately repeated, and thus the influence of spatial harmonics easily occurs and distortion easily occurs in the voltage.

[0241] However, even so, since the absolute value of the difference between the calculated value and the set value of the eccentricity is obtained to be less than 0.1 mm, it is considered that the accuracy is sufficient for detecting the contact between the rotor and the stator, which is the object of the present invention.

[0242] Also, the virtual rotor radius r and the virtual winding representative position θ rmck used in the calculation of the eccentricity (a1', a2') are values obtained by setting the eccentricity (a1, a2) = (0.0 mm, -0.5 mm) in advance, but it can also be said from this example that there is no problem even if different eccentricities (a1', a2') are used or the same values are used.

[0243] Furthermore, in this example, it was shown that the amount of eccentricity can be calculated even when the rotor of the electric motor is stationary. This brings about a special effect that the amount of eccentricity can be calculated even in a situation where it is not desired to move the main shaft such as the crankshaft of the mechanical device.

[0244] <Fourth Embodiment of Eccentricity Calculation Device and Method for Rotating Electric Machinery> In the first, second, and third embodiments, the windings of the U-phase, V-phase, and W-phase of the electric motor 110 are each composed of a plurality of Nw windings connected in series or in parallel, and the electric motor 110 appears to be configured as a single-phase multi-phase winding electric motor. However, in the fourth embodiment, all of these plurality of windings, or a part of adjacent windings, are connected in series or in parallel, and a plurality of U-phase, V-phase, and W-phase windings are led out of the electric motor. An eccentricity calculation device and method for a multi-winding electric motor are shown.

[0245] FIG. 23 is an overall configuration diagram of a control device for a rotating electric machinery including an eccentricity calculation device for a rotating electric machinery according to the fourth embodiment of the present invention, and a mechanical device equipped with the rotating electric machinery. In addition, the parts common to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the detailed description thereof is omitted.

[0246] [Electric Motor] FIG. 24 is a cross-sectional view of a main part of an electric motor applied to a control device for a rotating electric machinery according to the fourth embodiment.

[0247] The electric motor 110-1 shown in FIG. 24 is a multi-phase electric motor. In FIG. 24, a general three-phase (U-phase, V-phase, W-phase) electric motor will be described. Further, the electric motor 110-1 will be described by taking a synchronous motor as an example, but it may be a general multi-phase AC motor (not only a synchronous motor but also an induction motor).

[0248] Similar to the single-phase winding motor 110 of the first embodiment, inside the motor 110-1, there are a plurality of Nw windings for each of the U-phase, V-phase, and W-phase, and each of the Nw windings of each phase is positioned at an interval of 2π / Nw from each other. The difference from the motor 110 of the first embodiment is that all of these Nw windings of the U-phase, V-phase, and W-phase, or the Nw windings of the U-phase, V-phase, and W-phase are respectively connected in series or parallel, and a plurality of U-phases, V-phases, and W-phases are led out to the outside of the motor.

[0249] As shown in FIG. 24, in the motor 110-1 of the fourth embodiment, all of the plurality of Nw windings of the U-phase, V-phase, and W-phase are led out to the outside of the motor.

[0250] Since the rotor 110b of the motor 110-1 is the same as that of the motor 110 of the first embodiment shown in FIG. 2, the description thereof is omitted.

[0251] FIGS. 25(1) to (Nw) are connection diagrams showing an example of the connection of each phase winding U k , V k , W k (k = 1, 2,..., Nw) of the motor shown in FIG. 24.

[0252] The terminal box of the motor 110 is provided with a terminal block capable of measuring the terminal voltage of the 3×Nw windings inside the motor, and a current sensor capable of measuring the 3×Nw winding currents. However, in this embodiment, as will be described later, it is not necessarily required to be provided with these, but it may be provided.

[0253] [Control Device for Rotating Electric Machine of Fourth Embodiment] In FIG. 23, the control device for the rotating electric machine of the fourth embodiment includes an eccentricity amount calculation device for the rotating electric machine, similar to the first embodiment. Also, similar to the first embodiment, the motor 110-1 is provided with a drive shaft 112 on the side (load side) connected to the mechanical device of the rotor, and the drive shaft 112 is connected to the servo press machine 100, which is a mechanical device.

[0254] In the control device of the rotary electric machine, current control devices (220-1 to 220-Nw) for controlling a plurality of sets of three-phase winding currents of the electric motor 110-1 are provided independently for each of the plurality of sets of three-phase windings. The current control device for the k-th winding (k = 1, 2,..., Nw) (the k-th winding current control device 220-k) will be described as a representative.

[0255] The three-phase AC voltage command (v ukc * , v vkc * , v wkc * ) output from the current control unit 230 of the k-th winding current control device 220-k is output to the PWM conversion unit 270, where it is PWM-converted and applied to the servo amplifier 260. To other inputs of the servo amplifier 260, three-phase AC power from the three-phase AC power supply 240 is converted into DC power by the converter 250, and the DC power is applied from the converter 250. The servo amplifier 260 is a device that converts DC power into three-phase AC power and is a well-known inverter. The servo amplifier 260 converts DC power into three-phase AC power according to the PWM-converted three-phase AC voltage command, applies the converted three-phase AC power to the k-th winding, and drives the electric motor 110-1. The current control units of the current control devices for other windings are also controlled in the same way.

[0256] Similar to the first embodiment, the control device of the electric motor 110-1 in this example has a normal operation mode for normally operating the electric motor 110-1 and an eccentricity amount calculation mode, and the mode selection unit 212 outputs a mode command M * indicating the normal operation mode or the eccentricity amount calculation mode to the upper control device 210 according to a selection instruction from the operator. The configuration of the upper control device 210 is the same as that of the first embodiment.

[0257] Next, a speed control and current control (vector control) system for a multi-phase motor with a plurality of windings will be briefly described.

[0258] A speed command N *is output to the positive input of the adder. The speed N calculated by the speed calculation unit 214 is added to the negative input of the adder, and the adder calculates the deviation between the speed command N * and the speed N (N * - N), and outputs the deviation (N * - N) to the speed control unit 213. The speed control unit 213 outputs a torque command T * corresponding to the deviation (N * . The torque command T * is input to the dc-qc axis current command calculation unit 216. The dc-qc axis current command calculation unit 216 is the same as that in the first embodiment.

[0259] The dc axis current command i dc * and the qc axis current command i qc * output from the dc-qc axis current command calculation unit 216 are input to the current control devices 220-1 to 220-Nw of each winding. The dc axis current command i dc * and the qc axis current command i qc * are added to the positive inputs of the respective adders. The negative inputs of the respective adders are added with the dc axis current i dck and the qc axis current i qck of the k-th winding from the coordinate conversion unit 236. The coordinate conversion unit 236 is a polyphase / dc-qc conversion unit, and performs a rotational coordinate conversion on the three-phase alternating current (i uk , i vk , i wk ) of the k-th winding detected by the current sensor 280 and the position θ re acquired by the motor position sensor 116 to obtain the dc axis current i dck and the qc axis current i qck . As described above, the position θ re may use sensorless control and use a value estimated and calculated from voltage and current information or the like.

[0260] The adder that inputs the dc axis current command i dc * and the dc axis current i dck is the dc axis current command i dc *and the dc-axis current i dck the deviation from it (i dc * - i dck ) is obtained, and the deviation (i dc * - i dck ) is output to the dc-axis current control unit 232. The adder that inputs the qc-axis current command i qc * and the qc-axis current i qck obtains the deviation between the qc-axis current command i qc * and the qc-axis current i qck (i qc * - i qck ), and the deviation (i qc * - i qck * ) is output to the qc-axis current control unit 234.

[0261] Based on the input deviation (i dc * - i dck ), the dc-axis voltage command v dck * of the k-th winding is output by the dc-axis current control unit 232. Based on the input deviation (i qc * - i qck ), the qc-axis voltage command v qck * of the k-th winding is output by the qc-axis current control unit 234.

[0262] The dc-axis current control unit 232 and the qc-axis current control unit 234 are configured by, for example, connecting a proportional controller (P control) and an integral controller (I control) in parallel. However, since the main object of the present invention is to calculate the amount of eccentricity, it is not limited to this. A derivative controller (D control) may be further added in parallel to form a so-called PID control. In short, as long as the controller is configured to control such that i dc * follows i dck and i qc * follows i qck , any controller may be used.

[0263] dc-axis voltage command v dck * and the qc-axis voltage command v qck * are applied to the coordinate conversion unit 238. The coordinate conversion unit 238 is a dc-qc / polyphase conversion unit, and the dc-axis voltage command v dck * and the qc-axis voltage command v qck * and the position θ re acquired from the motor position sensor 116 are used to perform a rotational coordinate conversion to the three-phase AC voltage commands v ukc * and v vkc * and v wkc * As described above, the position θ re may use a value estimated and calculated from voltage-current information or the like, and the motor position sensor 116 is not necessarily required. The three-phase AC voltage commands v ukc * and v vkc * and v wkc * for the k-th winding are PWM-converted by the PWM conversion unit 270 as described above and then output to the servo amplifier 260, where they are amplified and output to the k-th winding of the motor 110-1. Thereby, the motor 110-1 is current-controlled (vector-controlled). The other windings are also vector-controlled in the same manner.

[0264] The above current control is applicable to polyphase AC with three or more phases. By performing a coordinate conversion that synchronizes the polyphase AC current with the rotor to generate a two-dimensional current vector and controlling this vector, it is essentially the same whether it is three-phase or polyphase, and it goes without saying that it is not limited to three-phase.

[0265] In the first embodiment, a measurement unit for measuring the terminal voltages of the 3×Nw windings provided in the motor 110 is provided. However, in this embodiment, as will be described later, the dc-axis voltage command v dck * and the qc-axis voltage command v qck *(k = 1, 2, …, Nw) is used to calculate the eccentricity, so the voltage measurement unit is not necessarily required, but it may be provided. Also, the current sensors for measuring the 3×Nw winding currents in the first embodiment can be diverted from the current sensors 280 of the current control devices 220-1 to 220-Nw in this embodiment. Also, when harmonics are superimposed on the measured value of the dc-axis current i dck or the measured value of the qc-axis current i qck , in order to reduce the influence of harmonics, instead of the measured value of the dc-axis current, the dc-axis current command value i dc * is used for the calculation of the eccentricity, and instead of the measured value of the qc-axis current, the qc-axis current command value i qc * may be used.

[0266] [Hardware Configuration of the Eccentricity Calculation Device for the Rotating Electric Machine in the Fourth Embodiment] The hardware configuration of the eccentricity calculation device for the rotating electric machine in the fourth embodiment can be made the same as that of the first embodiment shown in the block diagram of FIG. 5. This eccentricity calculation device is incorporated in the control device of the rotating electric machine as shown in FIG. 23.

[0267] The descriptions of the processor 370 and the input / output interface 390 shown in FIG. 5 are the same as those in the first embodiment, so they are omitted.

[0268] Also, the memory 380 stores the motor constant and the calculation formula for the eccentricity of the motor 110-1. The constant and the calculation formula for the eccentricity of the motor 110-1 are the same as the calculation formulas for the eccentricity shown in the first embodiment or the second embodiment. In the fourth embodiment, by changing the dc-axis voltage v dck and the qc-axis voltage v qck (k = 1, 2, …, Nw) of the k-th winding used in the calculation method of the first embodiment or the second embodiment to the dc-axis voltage command v dck * and the qc-axis voltage command v qck * (k = 1, 2, …, Nw), the eccentricity can be calculated in the same way.

[0269] Furthermore, the memory 380 stores various command data (in this example, the DC axis voltage command v of the kth winding) during the current control of the motor. dck * , qc-axis voltage command v qck * ), and the measurement data (dc axis current of the kth winding i dck , qc axis current i qck ) and the eccentricity error angle Δθ of each winding calculated from the motor constants and measurement data. rek , and Δθ rek tan Δθ calculated from rmk (k=1, 2, . . . , Nw) is temporarily stored, and when the amount of eccentricity is calculated, it functions as a storage device for storing the amount of eccentricity.

[0270] As in the first embodiment, the host controller 210 can also be configured by a computer. In this case, the host controller 210 and the eccentricity calculation device 300 may be configured by the same computer or may be configured by separate computers. The eccentricity amount display device 350 and the abnormality warning device 360 ​​are similar to those in the first embodiment, and therefore the description thereof will be omitted.

[0271] In the fourth embodiment, the dc axis voltage command v dck * , qc-axis voltage command v qck * Therefore, it is not necessary to provide a terminal for voltage measurement in the motor 110-1 or a voltage measuring unit in the control device of the motor 110-1. Also, the current sensor 280 can be the same as that in the current control devices 220-1 to 220-Nw for each winding. This provides a special effect that the amount of eccentricity can be calculated using a normal control device that controls a motor with multiple windings.

[0272] Furthermore, in the first embodiment, it was necessary to calculate the dc-qc axis voltage and current of each winding separately from the dc-qc axis voltage and current used in motor control, but in the fourth embodiment, the dc-qc axis voltage and current values ​​used in motor control can be used as they are, thereby reducing the calculation load.

[0273] <Fifth Embodiment of Eccentricity Calculation Device and Method for Rotating Electric Machinery> FIG. 26 is an overall configuration diagram of a control device for a rotating electric machinery including an eccentricity calculation device for the rotating electric machinery according to the fifth embodiment of the present invention, and a mechanical device equipped with the rotating electric machinery. Note that parts common to the first embodiment and the fourth embodiment shown in FIGS. 1 and 23 are denoted by common reference numerals, and detailed descriptions thereof are omitted.

[0274] The first to fourth embodiments are methods for calculating the eccentricity during the operation of the motor by the current control device. However, in the fifth embodiment, another motor for external driving is used to operate the motor as a generator, and the dc-axis voltage v of the motor 110-1 dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qck (k = 1, 2,..., Nw) are used to calculate the eccentricity.

[0275] [Motor] In FIG. 26, the motor 110-1 is the same as the motor in the fourth embodiment shown in FIGS. 24 and 25, and all Nw U-phase, V-phase, and W-phase windings are led out of the motor. Note that for the motor applied to the fifth embodiment, similar to the motors in the first to third embodiments, the U-phase, V-phase, and W-phase windings of the stator are each composed of a plurality of Nw windings U k , V k , W k (k = 1, 2,..., Nw) are connected in series or in parallel, and a set of multi-phase windings may be used to lead the terminals U, V, and W to the terminal box (not shown) of the motor. Also, since the motor 110-1 is operated as a generator by another external driving motor 115 for external driving, it may be a generator dedicated to power generation.

[0276] The motor 110-1 is provided with terminals TU uk , v vk , v wk (k = 1, 2,..., Nw) such that the terminal voltages can be measured, and TNU k , TV k , TNV k , and TNV k, TW k and TNW k (k = 1, 2, …, Nw) are respectively provided and are led out to the terminal box (not shown) of the motor 110-1. Also, the current i uk , i vk , i wk (k = 1, 2, …, Nw) of the k-th winding can be measured. Between the terminals TU k and TNU k , between the terminals TV k and TNV k , between the terminals TW k and TNW k (k = 1, 2, …, Nw) (not shown), current sensors S uk , S vk , S wk (k = 1, 2, …, Nw) are respectively provided. Also, when the terminals TU k and TNU k , TV k and TNV k , TW k and TNW k (k = 1, 2, …, Nw) are open and no power is supplied to the load device (not shown), the current sensors can be dispensed with.

[0277] [External drive motor] The external drive motor 115 is a motor for operating the motor as a generator. The external drive motor 115 may be any type of motor, such as a DC motor, a single-phase AC motor, or a polyphase AC motor. In the fifth embodiment, the external drive motor 115 is a three-phase AC motor. The external drive motor 115 is driven by an external drive power source 242 suitable therefor.

[0278] The external drive motor 115 and the motor 110-1 have their respective drive shafts 112 and 117 connected by a coupling 113. By operating the external drive motor 115 as a motor, the motor 110-1 is operated as a generator.

[0279] [Motor voltage and current measurement unit, coordinate conversion unit, and eccentricity calculation device] The terminal voltage v uk , v vk , vwk and the winding current i uk i vk i wk (k = 1, 2, …, Nw) are measured by the voltage - current measuring unit 332 of the motor 110 - 1. One end of each of the Nw voltage sensor cables of each phase is connected to the terminals TU k and TNU k TV k and TNV k TW k and TNW k of the motor respectively. The other ends of the current sensors S k and TNU k TV k and TNV k TW k and TNW k are connected to the voltage - current measuring unit 332. One end of each of the Nw poly - phase current sensor cables of each phase is connected to these current sensors S uk S vk S wk respectively. The other ends of these sensor cables are connected to the voltage - current measuring unit 332 to measure the terminal voltage v uk v vk v wk and the winding current i uk i vk i wk (k = 1, 2, …, Nw).

[0280] Also, the coordinate conversion unit 342 uses the measured values of the terminal voltage v uk v vk v wk and the winding current i uk i vk i wk (k = 1, 2, …, Nw) of the k - th winding of the motor 110 - 1 and the position θre obtained by the motor position sensor 116 to perform a rotational coordinate conversion from equations (1) and (2) to the dc - axis voltage v dck qc - axis voltage v qck dc - axis current i dck qc - axis current i qck (k = 1, 2, …, Nw).

[0281] Here, motors such as those in FIGS. 24 and 25 have the terminals TNU of the k - th winding (k = 1, 2, …, Nw)k , TNV k , TNW k are independently connected by their respective windings. In this case, the line-to-line voltage v uvk , v vwk , v wuk of the k-th winding is measured, and the dc-axis voltage v dck and the qc-axis voltage v qck can also be obtained by the following formula.

[0282]

Equation

[0283] According to Equation (21), even in the case of a motor where the terminals TNU k , TNV k , TNW k are not drawn out, the dc-axis voltage v dck and the qc-axis voltage v qck can be obtained.

[0284] Position θ reValues estimated and calculated from voltage-current information or the like may be used, and the motor position sensor 116 is not necessarily required.

[0285] However, when the position acquisition value of the motor position sensor 116 is not used, it is necessary to simultaneously measure the voltage and current acquisition values of each winding to clarify the phase relationship between the voltage and current of each winding. Simultaneous measurement of all windings is difficult. For example, when only two windings can be simultaneously measured, if one winding is used as a reference and other windings are simultaneously measured with the reference winding, the same effect as that of simultaneous measurement of all windings can be obtained.

[0286] The eccentricity calculation device 300 calculates the eccentricity from the values of v dck 、v qck 、i dck 、i qck (k = 1, 2,..., Nw) of these k-th windings and the motor constant. Since the method for calculating the eccentricity is the same as that in the first embodiment and the second embodiment, the description thereof is omitted.

[0287] The eccentricity display device 350 and the abnormality warning device 360 are also the same as those in the first embodiment, and thus the description thereof is omitted.

[0288] [Hardware Configuration of Eccentricity Calculation Device for Rotating Electric Machine in Fifth Embodiment] Since the hardware configuration of the eccentricity calculation device for the rotating electric machine in the fifth embodiment is the same as that in the first embodiment shown in the block diagram of FIG. 5, the description thereof is omitted.

[0289] In the fifth embodiment, the eccentricity can be calculated by operating the motor 110-1 as a generator with the external drive motor 115. Therefore, the eccentricity can be calculated even in an environment without the current control device of the motor 110-1. Further, since this method does not require a current control device, it goes without saying that the eccentricity can be obtained in the same manner for a motor directly connected to an AC power supply for operation instead of external drive, or a motor operated by open-loop voltage control (for example, V / F control) without performing current feedback.

[0290] [Sixth Embodiment of Eccentricity Calculation Device and Method for Rotating Electric Machine] When a plurality of Nw windings U k , V k , W k (k = 1, 2, …, Nw) that constitute the windings of the U-phase, V-phase, and W-phase of the stator of the motor are all even, there must be a pair of two windings arranged at positions symmetric about the origin. An example when Nw = 4 is shown in Fig. 27.

[0291] In the case of the motor shown in Fig. 27, the pair of the first winding and the third winding, and the pair of the second winding and the fourth winding are at positions symmetric with respect to the origin O.

[0292] Here, after obtaining tanΔθ rmk (k = 1, 2, …, Nw) from the voltage and current of each winding, when solving the Nw equations obtained by substituting into Equation (8) or Equation (19) simultaneously, if the eccentric amount is obtained by solving two equations corresponding to two windings arranged symmetrically about the origin simultaneously, there is a problem that abnormal values are calculated.

[0293] The above problem will be described in detail.

[0294] Equation (8), which is an equation showing the relationship between the eccentric amount and the eccentric error angle, is summarized with respect to the x-direction eccentric amount a1 and the y-direction eccentric amount a2 to obtain Equation (22).

[0295]

Equation

Equation

[0296] When Nw is an even number other than 2 (Nw = 4, 6, 8,...), the eccentricity can be calculated from two equations corresponding to two windings not located symmetrically about the origin. In the example of Nw = 4 in Fig. 27, a normal value of eccentricity can be obtained from two equations corresponding to the first and second windings, or the first and fourth windings, or the second and third windings, or the third and fourth windings, respectively.

[0297] When Nw = 2, since the two windings are arranged symmetrically about the origin, a normal value of eccentricity cannot be obtained by the previous methods.

[0298] When Nw = 2, instead of obtaining the eccentricity from the equations of the two windings, it can be solved by deriving two equations from only one winding.

[0299] As also described in the foregoing embodiments, the virtual rotor radius r and the virtual winding representative position θ rmck vary depending on the operating conditions. Utilizing this, by deriving two equations in which θ rmck in equation (22) is different under two different operating conditions, the eccentricity can be obtained without an indeterminate solution occurring. Also, for one equation, there are two constants, the virtual rotor radius r and the virtual winding representative position θ rmck . As will be described later, it has been confirmed that the principle that r and θ rmck are approximately equal regardless of the eccentricity holds for two windings as well under the same operating conditions.

[0300] By using this, two equations can be derived for one operating condition by measuring or analyzing voltage and current in advance for two eccentric amounts, and r and θ rmck can be obtained.

[0301] Summarizing the above, the method for calculating the eccentric amount when Nw = 2 is as follows.

[0302] First, as data to be measured or analyzed in advance, for one winding, measure or analyze the voltage and current under two eccentric amounts (a1, a2) and (b1, b2) and two operating conditions A and B. That is, perform a total of 4 patterns of measurement or analysis as shown in [Table 22] below.

[0303]

Table 22

[0304] Then, substitute the eccentric amount (a1, a2) corresponding to the condition of No. 1 and tanΔθ rmkA into the equation obtained by substituting into Equation (8) or Equation (19), and substitute the eccentric amount (B1, B2) corresponding to the condition of No. 2 and tanΔθ ’ rmkA into the equation obtained by substituting into Equation (8) or Equation (19), and solve the equations to obtain the virtual rotor radius r A , the virtual winding representative position θ rmckA corresponding to the operating condition A. Alternatively, r A , θ rmckA that satisfy both equations can be obtained by the least squares method. Specifically, r A , θ rmckAcan be found by searching for

[0305]

number

[0306]

number

[0307] To calculate the amount of eccentricity, measure or analyze the voltage and current for two operating conditions A and B for the same winding as in the preliminary measurement or analysis, and then use the r A , θ rmckA and r obtained under operating condition B B , θ rmckB However, assuming that the principle that the eccentricity is approximately equal regardless of the amount of eccentricity under the same operating conditions also holds for two windings, the equations can be calculated by simultaneously setting up equation (8) or (19) corresponding to operating condition A and equation (8) or (19) corresponding to operating condition B, as in the first to third embodiments described above.

[0308] To verify the above validity, according to the flowchart shown in FIG. 10, the eccentricity calculation mode for Nw = 2 was verified by magnetic field analysis.

[0309] FIG. 28 is a diagram showing a cross-sectional view of the main part of the motor and mechanical dimensions used to verify the validity of the eccentricity calculation method according to the sixth embodiment. Further, FIG. 29 is a diagram showing a cross-sectional view of the main part of the motor, coil arrangement, and connection, showing all the coil arrangements of only the U phase, and showing only the start and end of the windings for the V and W phases.

[0310] The motors shown in FIGS. 28 and 29 are three-phase permanent magnet synchronous motors with 8 poles and 30 slots of distributed windings.

[0311] The stator windings connect two windings of the same phase in series. Also, the magnets are of the arc-shaped surface magnet type.

[0312] In the sixth embodiment, similar to the first and second embodiments, the brake 170 is opened to operate at a constant rotational speed, and the dc-axis current command i dc * , qc-axis current command i qc * are made constant, and the steady state is assumed where the average currents of the dc-axis current i dck , qc-axis current i qck of the k-th winding (k = 1, 2) are constant.

[0313] In calculating the eccentricity of the motor with Nw = 2, in order not to generate abnormal solutions (indeterminate solutions), the voltage and current values of either one of the first winding or the second winding are used for calculation. In this embodiment, the eccentricity is calculated using only the voltage and current values of the first winding. However, the eccentricity may also be calculated using only the voltage and current values of the second winding, and the average with the eccentricity calculated using the first winding may be used as the eccentricity calculation value. Also, in this embodiment, from equations (17) and (18) of the second embodiment, tanΔθ rm1A , tanΔθ ’ rm1A , tanΔθ rm1B , tanΔθ ’1B Calculate it.

[0314] First, as pre-analysis data for eccentricity calculation, the eccentricities (a1, a2) = (0.0 mm, -0.5 mm) and (b1, b2) = (-0.3 mm, -0.4 mm) are set in advance, and when the motor is operated under two operating conditions A and B, the average values of v dc1 of the first winding, v qc1 i dc1 i qc1 are shown in [Table 23].

[0315]

Table 23

[0316]

Table 24

[0317]

Table 25

[0318]

Table 26

[0319]

Table 27

[0320] Incidentally, substituting the value of tanΔθ under the eccentricity (a1, a2) in [Table 25] and operating condition A into the left side of Equation (19), and substituting r rm1A in [Table 26] and θ A , θ rmc1A into the right side of Equation (19), and applying the obtained equation to the simultaneous equations of the value of tanΔθ under the eccentricity (a1, a2) in [Table 25] and operating condition B substituted into the left side of Equation (19) and rB, θ rm1B in [Table 27] substituted into the right side of Equation (19), the result of obtaining the eccentricity (a1, a2) is shown in [Table 28]. rmc1B

[0321]

Table 28

[0322] Also, substituting the value of tanΔθ under the eccentricity (b1, b2) and operating condition A into the left side of Equation (19), and r ’ rm1A into the left side of Equation (19),A and θ rmc1A The equation obtained by substituting into the right side of Equation (19), and tanΔθ under the eccentricity (b1, b2) and operating condition B ’ rm1B Substitute the value of into the left side of Equation (19), and r B and θ rmc1B Apply to the simultaneous equations of the equation obtained by substituting into the right side of Equation (19) to obtain the eccentricity (a1, a2). The results are shown in [Table 29].

[0323]

Table 29

[0324] Next, when the arbitrary eccentricities are (a1’, a2’) = (-0.2 mm, 0.4 mm), (0.6 mm, -0.7 mm), (0.9 mm, 0.2 mm), (0.0 mm, 0.0 mm), the average values of v dc1 ’ v qc1 ’ i dc1 ’ i qc1 ’ of the first winding when the motor is operated under the same operating condition A as before are shown in [Table 30].

[0325]

Table 30

[0326]

Table 31

[0327]

Table 32

[0328]

Table 33

[0329] From the above, it is certain that the validity of the eccentricity calculation method for the case of Nw = 2 has been verified.

[0330] Also, in the sixth embodiment, a plurality of Nw windings U k that make up the windings of the U-phase, V-phase, and W-phase of the stator k and V kIn a motor having (k = 1, 2, …, Nw), although a method for calculating an eccentricity amount by measuring voltages and currents of only one winding in the case of Nw = 2 has been shown, it has been confirmed that this method is applicable not only to motors with Nw = 2 but also to motors with Nw ≥ 3.

[0331] Among the plurality of windings shown in the sixth embodiment, the method for calculating the eccentricity amount using the measured values or analysis values of the voltages and currents of only one winding requires that the voltages and currents be measured or analyzed in advance under two operating conditions and two eccentricity amounts. However, since only one winding needs to be measured, it has a special effect of significantly reducing the number of voltage sensor cables, current sensors, and current sensor cables.

[0332] <Seventh Embodiment of Eccentricity Amount Calculation Device and Method for Rotating Electric Machinery> The seventh embodiment shows a specific example of a servo press machine in which a motor is incorporated, to which the eccentricity amount calculation device and method for a rotating electric machinery are applied. Here, an example applied to a crank press as a press machine is shown, but it may be a servo press machine with various mechanisms such as a knuckle mechanism and a link mechanism, not limited to a crank mechanism. 。

[0333] FIG. 30 is an overview diagram of the servo press machine shown in FIG. 1. Also, in FIG. 30, the same reference numerals are assigned to the parts common to the servo press machine 100 shown in FIG. 1.

[0334] In FIG. 30, a motor 110, which is a power source of the servo press machine 100, is incorporated in the servo press machine 100. A main gear 120 is meshed with a gear 114 provided on the drive shaft 112 of the motor 110, and a crank mechanism (crank shaft 130, connecting rod 140) of the servo press machine 100 is connected to the main gear 120. The motor 110 is a polyphase alternating current motor as described in the foregoing embodiments.

[0335] The crank mechanism is configured to enable the slide 150 to move up and down with respect to the stationary bolster 160.

[0336] The upper die 152 is mounted on the slide 150, and the lower die 162 is mounted on the bolster 160. When the processing material 194 is between the upper die 152 and the lower die 162, if the slide 150 is lowered to bring the upper die 152 into contact with the lower die 162, press working can be performed on the processing material 194. FIG. 30 shows a situation where the processing material 194 in the form of a coiled sheet material is being fed by the feeder 192 to the servo press machine 100.

[0337] In addition, a crankshaft position sensor 132 is attached to the crankshaft 130 of the servo press machine 100 simply shown in FIG. 1 and the like, and is configured to be able to grasp the position of the crankshaft 130. A rotary encoder or the like is applied to the crankshaft position sensor 132. The position information θ of the crankshaft 130 obtained by the crankshaft position sensor 132 rc is input to the upper control device 210, and based on this information and the like, the position control of the slide 150 of the servo press machine 100 can be performed.

[0338] Since the servo press machine 100 is freely rotationally driven by the forward rotation, reverse rotation, and speed variable control of the electric motor 110, not only the crank mechanism but also the slide motion of other mechanisms, the slide motion conforming to the molded body including stationary, or various slide motions such as forward and reverse pendulum motions can be freely set, and these can be switched and used. For this reason, the accuracy, productivity, and adaptability for the press molded body can be expanded.

[0339] The amount of eccentricity can be measured, for example, in the state where the electric motor of the servo press machine 100 is stationary at the operation preparation stage and in the state where the electric motor is operating during slide driving.

[0340] First, the approximate startup method, operation method, and stop method of the servo press machine 100 will be described according to the flowchart of FIG. 31.

[0341] Before startup, the servo press machine 100 is stationary and the power is off.

[0342] First, in step S21, the press operator turns on the main breaker 184 provided on the control panel 182 shown in FIG. 30 to start the servo press machine 100. When it is turned on, the main power lamp 180e on the main operation panel 180 shown in FIG. 32 lights up.

[0343] Next, in step S22, the press operator turns the operation power switch (key switch) 180f on the main operation panel 180 from "off" to "on". When it is turned on, power is supplied to the operation display 180g on the main operation panel 180, enabling the display of the current slide position during servo press operation, the motion of the slide 150, the setting of the speed of the slide 150, and the switching between the eccentricity calculation mode and the normal operation mode of the electric motor 110 described in the first embodiment. Further, the main operation panel 180 is communicatively connected to the control device of the electric motor shown in FIG. 1, and can also display the eccentricity calculation value and the abnormal alarm content described in the foregoing embodiments on the operation display 180g.

[0344] Next, in step S23, the operator turns on the oil supply pump button (with lamp) 180c on the main operation panel 180. When the oil supply pump button 180c is turned on, the lamp of the oil supply pump button 180c blinks, and mechanical oil starts to be supplied to the drive part of the servo press machine 100 (for example, the gear 114 of the drive shaft 112 of the electric motor 110 and the main gear 120 of the crankshaft 130) and the bearing (not shown) of the electric motor 110. When the oil supply is performed for a predetermined time, the lamp of the oil supply pump button 180c changes from blinking to constantly on, indicating that the oil supply is completed.

[0345] Next, in step S24, the press operator turns on the servo power input button (with a lamp) 180a on the main operation panel 180 to supply energy to the energy storage capacitor (not shown, connected to the DC circuit between the converter 250 and the servo amplifier (inverter) 260 in FIG. 1) of the control device of the electric motor. When the servo power input button 180a is turned on, the lamp of the servo power off button 180b, which has been constantly lit until then, goes out, the lamp of the servo power input button 180a blinks, and electrical energy for operating the electric motor 110 starts to be stored. When the energy supply to the energy storage capacitor is completed, the operation display 180g displays that the operation preparation of the servo press machine 100 is completed. Also, the operable lamp 180d on the main operation panel 180 lights up. Also, the brake 170 of the electric motor 110 performs an opening operation.

[0346] Next, in step S25, the press operator switches the operation selection switch 190e of the operation button box 190 shown in FIG. 33 from "off" to the operation mode he / she wants to operate in order to drive the slide 150 of the servo press machine 100. One of the operation modes of the servo press machine 100 is the "inch operation mode". In this mode, while the operation button 190d of the operation button box 190 in FIG. 33 is being pressed, the slide 150 moves in the set motion and stops immediately when the operation button 190d is released. Also, in the "continuous operation mode", when the continuous preparation lamp-equipped button 190f of the operation button box 190 is pressed and the operation button 190d is pressed within a predetermined time, the slide 150 continuously operates in the set motion, continues to operate even when the operation button 190d is released, and stops at the set slide position when the set point stop button 190b is pressed. Here, it is assumed that the continuous operation mode is selected.

[0347] In step S26, the press operator presses the button 190f with a continuous preparation lamp on the operation button box 190. Next, the press operator presses the operation button 190d within a predetermined time after pressing the button 190f with a continuous preparation lamp. There is one operation button 190d on each of the left and right sides, and the slide cannot be driven unless both are pressed. In the case of the continuous operation mode, when the operation button 190d is pressed once, the slide 150 is driven, and the slide 150 continues to move even if released.

[0348] When it is desired to stop the slide drive (step S27), the press operator presses the set point stop button 190b on the operation button box 190. Then, it stops when the slide 150 reaches the set position. When it is desired to emergently stop the servo press machine 100, pressing the emergency stop button 190c will cause the slide 150 to stop immediately.

[0349] When it is desired to turn off the power of the servo press machine 100 (step S28), the operator first turns on the servo power off button 180b on the main operation panel 180. When the servo power off button 180b is turned on, the energy stored in the energy storage capacitor is released, and the motor 110 cannot be driven.

[0350] In step S29, the operation power switch (key switch) 180f is switched from "on" to "off", and the power of all devices (except the main operation panel) of the servo press machine 100 is turned off.

[0351] In step S30, the main breaker 184 provided on the control panel 182 is switched from on to off. The main power lamp 180e on the main operation panel 180 goes out, and the total power of the servo press machine 100 is turned off.

[0352] [Calculation of the eccentricity at the stationary state of the motor in the operation preparation stage] The calculation of the eccentricity at the stationary state of the motor in the operation preparation stage of the servo press machine 100 is performed at step S24.

[0353] Specifically, after turning on the servo power input button (with lamp) 180a and completing the energy supply to the energy storage capacitor, power is applied to the motor 110 for calculating the eccentricity. Since the slide 150 cannot be driven without the operation of the press operator, the brake 170 of the motor 110 is closed to lock the rotor of the motor 110 as in the eccentricity calculation mode of the third embodiment. Then, as in the third embodiment, in order to obtain the voltage related to the magnetic flux linkage of the motor winding even in the stationary state, the dc-axis current command i dc * , qc-axis current command i qc * is controlled to be a steady alternating current, and the eccentricity is calculated from the AC effective values of the dc-axis current i dck , qc-axis current i qck , dc-axis voltage v dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qck (k = 1, 2,..., Nw). As described in the third embodiment, the dc-axis current command i dc * , qc-axis current command i qc * does not have to be a steady alternating current, and any current command that generates a voltage related to the magnetic flux linkage of the motor winding is acceptable. For example, a step-shaped or ramp-shaped current command may be used.

[0354] Since this current command is specified by the designer in advance, the dc-axis voltage v dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qck , etc. in this current command are measured or analyzed in advance to obtain the values of the virtual rotor radius r and the virtual winding representative position θ rmck for calculating the eccentricity, and these values are stored in the memory 380 and in the memory inside the control device of the motor.

[0355] These values, together with the dc-axis voltage v dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qckFrom the measurement values, the amount of eccentricity can be calculated in the same manner as in the foregoing embodiments.

[0356] After calculating any one or more of the amount of eccentricity, the eccentricity error angle, and the value corresponding to the eccentricity error angle, if any one or more of the amount of eccentricity, the eccentricity error angle, and the value corresponding to the eccentricity error angle do not exceed the threshold value, the operation display 180g displays that the operation preparation of the servo press machine 100 is completed. When any one or more of the amount of eccentricity, the eccentricity error angle, and the value corresponding to the eccentricity error angle exceed the threshold value, as shown in FIG. 34, the operation display 180g displays any one or more of the value of the amount of eccentricity, the eccentricity error angle, and the value corresponding to the eccentricity error angle, and the presence or absence of abnormality.

[0357] [Calculation of Eccentricity during Motor Operation in Slide Driving] In the case of calculating the amount of eccentricity in the motor operation state during slide driving, after the operation preparation is completed in step S24, on the operation display 180g, the eccentricity calculation mode is selected from among the mode selection units 212 described in the first embodiment. FIG. 35 shows an example of the screen of the operation display 180g when the eccentricity calculation mode is selected. Although there are places on the screen for displaying the value of the amount of eccentricity and the presence or absence of abnormality, at this point, the columns for displaying the value of the amount of eccentricity and the presence or absence of abnormality are blank.

[0358] In the eccentricity calculation mode of the servo press machine 100 having a crank mechanism, for example, a motion is set such that the crankshaft 130 rotates at a constant speed, that is, the drive shaft 112 of the electric motor 110 rotates at a constant speed. This is set when "standard" on the operation display 180g shown in FIG. 35 is selected. Since this motion is a motion specified by the press designer in advance, the dc-axis voltage v dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qck etc. are measured or analyzed to obtain the virtual rotor radius r and the virtual winding representative position θ for calculating the eccentricity rmckThe value is obtained and stored in the memory 380, and is also displayed on the operation display 180g as shown in FIG. 35. When "Standard" is selected, the virtual rotor radius r and the virtual winding representative position θ rmck The display location cannot be changed by the touch panel and is, for example, grayed out.

[0359] The motion when "Standard" is selected is different from the motion set by the press operator. However, as shown in FIG. 36, if "Arbitrary" is selected, the eccentricity can be calculated with the motion set by the press operator. In that case, the dc-axis voltage v dck and the qc-axis voltage v qck the dc-axis current i dck and the qc-axis current i qck etc. are measured or analyzed to obtain in advance the values of the virtual rotor radius r and the virtual winding representative position θ rmck When "Arbitrary" is selected, the locations for inputting (displaying) the values of the virtual rotor radius r and the virtual winding representative position θ rm c k become white and can be input via the touch panel. The operator can input and store in the memory 380 the values of the virtual rotor radius r and the virtual winding representative position θ rmck in the motion set by the press operator. Here, it is assumed that "Standard" is selected.

[0360] In step S26, when the operation button 190d is pressed, the slide 150 is driven. When the drive shaft 112 of the electric motor 110 rotates at a constant speed and the load on the electric motor 110 is substantially constant, the dc-axis voltage v dck the qc-axis voltage v qck the dc-axis current i dck and the qc-axis current i qckThe average value becomes almost constant, and the amount of eccentricity can be calculated from the measured values of these values in the same manner as in the foregoing embodiment. In particular, when the slide 150 is at the highest position (near top dead center), the mass of the slide 150 acts only in the vertical direction of the crankshaft 130. That is, the force in the rotational direction for holding the slide mass is not applied to the crankshaft 130, and almost no load torque is applied to the electric motor 110. Also, no pressing operation is performed near top dead center. Due to these two factors, the rotational torque of the electric motor 110 is small near top dead center. Since the position of the crankshaft 130 is grasped by the crankshaft position sensor 132 and output to the upper control device 210, when the position near top dead center is detected by the crankshaft position sensor 132, the dc-axis voltage v dck , qc-axis voltage v qck , dc-axis current i dck , qc-axis current i qck can be measured. Since the current value is small near top dead center, the motor constants of the terms including i dck , i qck in equations (4), (10), and (17), and the influence of their variations can be reduced, and a special effect can be obtained.

[0361] Also, in the eccentricity calculation mode of the motor operating state during slide driving, the brake 170 is in the open state, but the brake 170 may be closed, and the eccentricity may be calculated in the motor stationary state in the same manner as in the method in the operation preparation stage.

[0362] When the calculation of the amount of eccentricity is completed, the value of the amount of eccentricity, the presence or absence of abnormality, etc. are displayed on the operation display 180g. FIG. 37 shows an example of the screen of the operation display 180g after the amount of eccentricity is calculated.

[0363] When performing normal operation, as shown in FIG. 38, if the normal operation mode is selected on the operation display 180g, it is possible to operate in the motion set by the press operator. On the operation display 180g in the normal operation mode, there is no display of "standard", "arbitrary", "virtual rotor radius", "virtual winding representative position", "eccentricity threshold value", "eccentricity", "presence or absence of abnormality", but they may be displayed.

[0364] In addition, the displayed values may include not only the eccentricity threshold value and the eccentricity amount, but also the threshold value of the aforementioned eccentricity error angle Δθ rek and the threshold value of tanΔθ rmk and the threshold value of Δθ rek and tanΔθ rmk values may be displayed.

[0365] [Others] In the present embodiment, for example, the hardware structure of a processing unit that executes various processes, such as the processor of the eccentricity calculation device, is various processors as shown below. The various processors include a CPU (Central Processing Unit), which is a general-purpose processor that executes software (program) and functions as various processing units, a programmable logic device (PLD), such as an FPGA (Field Programmable Gate Array), which is a processor whose circuit configuration can be changed after manufacturing, and a dedicated electric circuit, which is a processor having a circuit configuration specifically designed to execute specific processes, such as an ASIC (Application Specific Integrated Circuit).

[0366] One processing unit may be composed of one of these various processors, or may be composed of two or more processors of the same type or different types (for example, a plurality of FPGAs, or a combination of a CPU and an FPGA). Also, a plurality of processing units may be composed of one processor. As an example of configuring a plurality of processing units with one processor, first, as represented by a computer such as a client or a server, one processor is configured by a combination of one or more CPUs and software, and this processor functions as a plurality of processing units. Second, as represented by a System On Chip (SoC), there is a form in which a processor that realizes the functions of an entire system including a plurality of processing units with one IC (Integrated Circuit) chip is used. Thus, various processing units are configured as a hardware structure using one or more of the above various processors.

[0367] Furthermore, the hardware structure of these various processors is, more specifically, an electric circuit (circuitry) formed by combining circuit elements such as semiconductor elements.

[0368] Also, the present invention is not limited to the above-described embodiments, and includes various modifications. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Also, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible.

Explanation of Reference Numerals

[0369] 100... Servo press machine 110, 110-1... Electric motor 110a... Stator 110b... Rotor 112... Drive shaft 113... Coupling 114…Gear 115…External drive motor 116…Motor position sensor 117…Drive shaft 120…Main gear 130…Crankshaft 132…Crankshaft position sensor 140…Connecting rod 150…Slide 152…Upper die 160…Bolster 162…Lower die 170…Brake 172…Brake control unit 180…Main operation panel 180a…Servo power on button 180b…Servo power off button 180c…Oil pump button 180d…Operable lamp 180e…Main power lamp 180g…Operation display 182…Control panel 184…Main breaker 190…Operation button box 190b…Set point stop button 190c…Emergency stop button 190d…Operation button 190e…Operation selection switch 190f…Button with continuous preparation lamp 192…Feeding device 194…Workpiece 210…Upper control device 212…Mode selection section 213…Speed control section 214…Speed calculation section 216…DC-QC axis current command calculation section 216A…DC axis current command and QC axis current command calculation section for eccentricity calculation mode 216B…DC axis current command and QC axis current command calculation section for normal operation mode 220, 220-1 to 220-Nw…Current control device 230…Current control section 232…dc axis current control unit 234…qc axis current control unit 236, 238, 340, 342…coordinate conversion unit 242…external driving power supply 250…converter 260…servo amplifier 270…PWM conversion unit 280…current sensor 300…eccentricity calculation device 310…eccentric error angle calculation unit 320…eccentricity calculation unit 330, 332…voltage and current measurement unit 350…eccentricity display device 360…abnormal alarm device 370…processor 380…memory 390…input / output interface S1~S7, S11~14, S21~S30…steps

Claims

1. An eccentricity calculation device for a rotating electrical machine, comprising a processor and a memory that stores calculation formulas for constants and eccentricity of a polyphase rotating electrical machine, wherein the processor, acquires a voltage command to the winding of each phase of the rotating electrical machine or a voltage applied to the winding of each phase, and a current command to the winding of each phase or a current flowing through the winding of each phase, and calculates the eccentricity of the rotating electrical machine based on the acquired voltage command or voltage, the current command or current, and the calculation formulas for the constants and eccentricity of the rotating electrical machine stored in the memory. An eccentricity calculation device for a rotating electrical machine.

2. The processor converts the acquired voltage command or voltage into a voltage command or voltage in a control d - qc coordinate system, and converts the acquired current command or current into a current command or current in a control d - qc coordinate system, and uses the converted voltage command or voltage and the converted current command or current for calculating the eccentricity of the rotating electrical machine. The eccentricity calculation device for a rotating electrical machine according to Claim 1.

3. The calculation formula for the eccentricity includes a first calculation formula for calculating an eccentricity error angle, which is the deviation angle between the d - qc coordinate system and the d - q coordinate system, and the processor substitutes the constants of the rotating electrical machine, the converted voltage command or voltage, and the converted current command or current into the first calculation formula to calculate the eccentricity error angle. The eccentricity calculation device for a rotating electrical machine according to Claim 2.

4. The constants of the rotating electrical machine stored in the memory include any one or more of the phase resistance, d - axis inductance, q - axis inductance, and number of pole pairs of the rotating electrical machine. The eccentricity calculation device for a rotating electrical machine according to Claim 3.

5. The calculation formula for the eccentricity includes a second calculation formula showing the relationship between the eccentricity error angle and the eccentricity, and the processor substitutes the eccentricity error angle calculated by the first calculation formula into the second calculation formula to calculate the eccentricity. The eccentricity calculation device for a rotating electrical machine according to Claim 3.

6. The processor, for each set of windings composed of multiple phases of the rotating electrical machine in the first calculation formula, calculates the eccentricity error angle under preset operating conditions for each of the multiple sets of windings. Substitute the calculated eccentricity error angles for each of the plurality of sets of windings into the second arithmetic expression including a virtual rotor radius, which is an unknown constant, and a virtual winding representative position to create a system of simultaneous equations. Calculate the virtual rotor radius and the virtual winding representative position that satisfy the system of simultaneous equations. Use the calculated virtual rotor radius and virtual winding representative position as constants in the second arithmetic expression under the operating conditions. An eccentricity amount calculation device for a rotating electric machine according to claim 5.

7. The set of windings constituting the rotating electric machine from multiple phases is two sets, namely a first winding and a second winding. An eccentricity amount calculation device for a rotating electric machine according to any one of claims 1 to 6.

8. The rotating electric machine is a motor or a generator. An eccentricity amount calculation device for a rotating electric machine according to any one of claims 1 to 6.

9. A method executed by an eccentricity amount calculation device for a rotating electric machine, comprising a processor and a memory storing arithmetic expressions for constants and eccentricity amounts of a polyphase rotating electric machine, a step in which the processor acquires a voltage command for each phase winding of the rotating electric machine or a voltage applied to each phase winding, and a current command for each phase winding or a current flowing through each phase winding; a step in which the processor calculates an eccentricity amount of the rotating electric machine based on the acquired voltage command or voltage, the current command or current, and the arithmetic expressions for the constants and the eccentricity amount of the rotating electric machine stored in the memory; An eccentricity amount calculation method for a rotating electric machine including these steps.

10. The step in which the processor includes coordinate-transforming the acquired voltage command or voltage into a voltage command or voltage in control d - c coordinate system, and coordinate-transforming the acquired current command or current into a current command or current in control d - c coordinate system, In the step of calculating the eccentricity amount of the rotating electric machine, the coordinate-transformed voltage command or voltage and the coordinate-transformed current command or current are used for calculating the eccentricity amount of the rotating electric machine. An eccentricity amount calculation method for a rotating electric machine according to claim 9.

11. A control unit that controls a polyphase rotating electric machine and operates a mechanical device by the rotating electric machine, an eccentricity amount calculation device for a rotating electric machine according to any one of claims 1 to 6, A control device for a rotating electric machine including these components.

12. A speed control unit that outputs a torque command based on the deviation between a preset speed command for the rotary electric machine and the speed of the rotary electric machine; A mode selection unit that selects a normal operation mode for normally operating the rotary electric machine or an eccentricity amount calculation mode for calculating an eccentricity amount in response to a selection instruction from an operator; A host control device that outputs a switching signal for switching between the normal operation mode or the eccentricity amount calculation mode based on a mode command output from the mode selection unit; A current command calculation unit that outputs a dc-axis current command and a qc-axis current command based on the torque command and the switching signal, and is provided with: When the normal operation mode is selected, the control unit outputs a dc-axis current command and a qc-axis current command for the normal operation mode from the current command calculation unit. When the eccentricity amount calculation mode is selected, the control unit outputs a dc-axis current command and a qc-axis current command for the eccentricity amount calculation mode from the current command calculation unit, or closes the brake to lock the rotor of the rotary electric machine, and controls the dc-axis current command and the qc-axis current command output from the current command calculation unit to be a current that generates a steady alternating current or a voltage related to the magnetic flux linkage of the motor winding of the rotary electric machine; The control device for a rotary electric machine according to claim 11.

13. A display device that displays any one or more of an eccentricity amount, an eccentricity error angle, and a value corresponding to the eccentricity error angle; The control unit causes the display device to display any one or more of the eccentricity amount, the eccentricity error angle, and the value corresponding to the eccentricity error angle calculated by the eccentricity amount calculation device; The control device for a rotary electric machine according to claim 11.

14. An abnormality warning device that warns of an abnormality in any one or more of an eccentricity amount, an eccentricity error angle, and a value corresponding to the eccentricity error angle; The control unit compares any one or more of the eccentricity amount, the eccentricity error angle, and the value corresponding to the eccentricity error angle calculated by the eccentricity amount calculation device with a threshold value serving as an abnormality determination criterion, and causes the abnormality warning device to warn of an abnormality when any one or more of the eccentricity amount, the eccentricity error angle, and the value corresponding to the eccentricity error angle are greater than or equal to the threshold value; The control device for a rotary electric machine according to claim 11.

15. The mechanical device is a servo press machine including the rotary electric machine, The rotary electric machine rotates the main shaft of the servo press machine, The control device for a rotary electric machine according to claim 11.

Images