WO2024009657A1 - Motor control device, motor control method, and elevator device - Google Patents

Abstract

Provided is a motor control device comprising an estimation processing unit which includes an axis error estimation unit for using a voltage and a current applied to a motor and a rotation speed of the motor to estimate an axis error estimation value of an axis error of the motor and a calculation processing unit which includes a detection error correction unit for correcting a detected rotation angle of the motor on the basis of the axis error estimation value and calculates the rotation speed and the rotation angle of the motor on the basis of the detected rotation angle after the correction. The motor control device controls the motor on the basis of the rotation speed and the rotation angle of the motor.

Description

Motor control device, motor control method and elevator device

The present invention relates to a motor control device, a motor control method, and an elevator device.

In order to perform precise torque and rotational speed control with a permanent magnet motor that uses permanent magnets for the field, information on the rotation angle of the rotor is required. There are two main methods for detecting rotation angle information: a direct detection method using a rotation angle sensor such as an optical encoder, magnetic encoder, or resolver, and a sensorless detection method that uses the saliency of the motor's induced voltage or inductance.

In the rotation angle sensor, a first-order mechanical angle rotation angle detection error occurs due to eccentricity between the motor rotation axis and the sensor rotation center at the time of installation. Further, depending on the characteristics of the rotation angle sensor itself, there is a possibility that a pulsation component that fluctuates depending on the rotation angle is generated. Here, the first order of mechanical angle represents one time the mechanical rotation frequency of the motor. For example, if the rotation frequency is 3000 rpm (rotations per minute), the first order of mechanical angle will be 50 Hz, and the second order of mechanical angle will be 50 Hz. becomes 100Hz.

In particular, a magnetic encoder that detects the rotation angle by attaching a permanent magnet to the motor rotation shaft and detecting the direction of the magnetic flux density emitted by the permanent magnet has the problem of easily producing a pulsating component that is synchronized with the rotation angle. there were. For example, pulsations of 50 Hz and 100 Hz sometimes occurred. Due to this problem, especially in applications where a large torque is required when the motor is running at low speed, and the resonance point of the mechanical system driven by the motor is located at a low frequency, the pulsating component synchronized with the rotation angle of the rotation angle sensor may There was a risk that vibration noise would become noticeable at rotational speeds where the resonance points of the mechanical system coincided.

Conventionally, a technique described in Patent Document 1 has been known as a method for reducing sensor detection errors caused by a deviation between the rotational position of a motor rotor and the position of a permanent magnet. This Patent Document 1 describes "error calculation means for calculating the error between the detected rotational position of the rotor and the magnetic pole position estimated by the magnetic pole position estimation means, and a permanent The present invention includes a deviation detection means for detecting a deviation between the actual position of the magnet and the detected rotational position of the rotor, and a correction means for correcting the detected deviation.

Japanese Patent Application Publication No. 9-56199

In the technique described in Patent Document 1, the amount of error between the detected magnetic pole position and the estimated magnetic pole position is assumed to be a constant value regardless of the rotation angle. Therefore, there has been a problem in that it is not possible to correct the pulsation component that varies depending on the rotation angle of the rotation angle sensor. If the pulsating component remains, the AC motor does not rotate at a constant rate and the rotational speed pulsates, which can cause vibrations and noise in various devices driven by the motor.

The present invention has been made in view of this situation, and it is an object of the present invention to drive a motor by correcting the pulsation component that varies depending on the rotation angle detected by the rotation angle sensor.

The motor control device according to the present invention controls the motor based on the rotation speed and rotation angle of the motor. This motor control device includes an estimation processing section having an axis error estimating section that estimates an axis error estimated value of the axis error of the motor using voltage and current applied to the motor and the rotational speed of the motor; The present invention includes a detection error correction section that corrects the detected rotation angle of the motor based on the corrected rotation angle, and a calculation processing section that calculates the rotation speed and rotation angle of the motor based on the corrected detected rotation angle.

According to the present invention, by correcting the detected rotation angle of the motor based on the estimated axis error value, the motor is driven by correcting the pulsation component that varies depending on the rotation angle detected by the rotation angle sensor. Vibration and noise can be reduced in various devices driven by motors.
Problems, configurations, and effects other than those described above will be made clear by the following description of the embodiments.

FIG. 1 is a schematic control diagram of a motor control system according to a first embodiment of the present invention. FIG. 2 is a block diagram showing an example of the internal configuration of a speed/angle calculation section according to the first embodiment of the present invention. 1 is a block diagram showing an example of a hardware configuration of a microcomputer according to a first embodiment of the present invention. FIG. 7 is a flowchart illustrating an example of control processing of the angle detection error sampling section and the detection error component calculation section according to the first embodiment of the present invention. FIG. 7 is a block diagram showing an example of the internal configuration of a speed/angle calculation section according to a second embodiment of the present invention. FIG. 7 is a block diagram showing an example of the internal configuration of a speed/angle calculation section according to a third embodiment of the present invention. It is a schematic block diagram which shows the example of the whole structure of the elevator apparatus based on the 4th Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functions or configurations are designated by the same reference numerals and redundant explanations will be omitted. It should be noted that the various components of the present invention do not necessarily have to exist independently, and it is possible that a plurality of components are formed as a single member, or that one component is formed of a plurality of members. It is allowed that a certain component is a part of another component, that a part of a certain component overlaps with a part of another component, etc.

[First embodiment]
First, a configuration example and an operation example of a motor control device according to a first embodiment will be described using FIGS. 1 to 4.
FIG. 1 is a schematic control diagram of a motor control system 1 according to a first embodiment of the present invention. The configuration of the motor control system 1 will be described below.

The motor control system 1 includes a motor 40, an inverter 30, a current detection section 31, a rotation angle sensor 50, and a motor control device 10.
Inverter 30 applies voltage to motor 40 and supplies current to motor 40 .
The current detection unit 31 detects the current of the motor 40.
The rotation angle sensor 50 detects the rotation angle of the motor 40.
Motor control device 10 controls the voltage that inverter 30 applies to motor 40 . The motor 40 can be controlled based on the rotation speed and rotation angle of the motor 40.

The motor control device 10 compares a rotational speed command ωr* obtained from an external higher-level control unit with a rotational speed ω calculated by a speed/angle calculation unit 20, which will be described later, and inputs a speed deviation to the speed control unit 102. .

For example, a proportional-integral (PI) control unit is used as the speed control unit 102, and an integral value of the speed deviation is output. A torque command T* obtained by adding the output of the speed control unit 102 and the starting torque that the motor control device 10 acquires from a higher-level control device (not shown) is input to the current command generation unit 103. Note that the starting torque represents a torque command value for the motor control device 10.

The current command generation unit 103 generates current commands Id*, d for the d-axis, which is the excitation axis (magnetic flux axis) on the rotational coordinate in vector control of the motor 40, so as to obtain a torque that matches the input torque command T*. Outputs the current command Iq* for the q-axis perpendicular to the axis.

Here, the configurations of the current detection section 31 and the uvw/dq coordinate conversion section 107 will be explained.
The current detection unit 31 is composed of a Hall CT (Current Transformer) or the like, and detects the three-phase currents Iu, Iv, and Iw of the U-phase, V-phase, and W-phase flowing through the motor 40 together with their waveforms. However, the current detection unit 31 does not necessarily need to detect currents of all three phases. The current detection unit 31 may detect the current of any two phases, and calculate the remaining one phase assuming that the three-phase currents are in a balanced state, thereby calculating the three-phase currents Iu, Iv, and Iw. .

The uvw/dq coordinate conversion unit 107 converts the three-phase currents Iu, Iv, and Iw of the motor 40 detected by the current detection unit 31 into a rotation coordinate system using the rotation angle calculation value θ input from the speed/angle calculation unit 20. The d-axis current value Id and the q-axis current value Iq are calculated. After the deviations between the d-axis current command Id* and q-axis current command Iq* and the motor d-axis current value Id and q-axis current value Iq (hereinafter referred to as "dq-axis current deviation") are calculated, dq The shaft current deviation is input to the current control section 104.

The current control unit 104 calculates the d-axis voltage command value Vd* and the q-axis voltage command value Vq* using the dq-axis current deviation and the rotational speed ω calculated by the speed/angle calculation unit 20. The d-axis voltage command value Vd* and the q-axis voltage command value Vq* are output to the dq/uvw coordinate conversion section 105 and the speed/angle calculation section 20.

The dq/uvw coordinate conversion unit 105 converts the d-axis voltage command value Vd* and the q-axis voltage command value Vq* into three-phase AC voltage using the rotation angle calculation value θ input from the speed/angle calculation unit 20. do. The converted three-phase AC voltage is output to the PWM processing section 106.

The PWM processing unit 106 performs PWM control of the three-phase AC voltage so that the output voltage of the inverter 30 follows the voltage command (d-axis voltage command value Vd*, q-axis voltage command value Vq*).
With the above configuration, the motor 40 is controlled to a desired rotational speed.

<Problems with conventional motor control methods>
Here, problems with the conventional control method for the motor 40 will be explained.
If the sensor detection angle θs of the rotation angle sensor 50 includes a k-th pulsation component synchronized with the rotation angle shown in the following equation (1) with respect to the true motor rotation angle θr, and the true motor rotation speed ωr is constant. do. At this time, the rotational speed detection value ωs obtained by directly differentiating the sensor detection angle θs is expressed by equation (2).

As shown in equation (2), the detected rotational speed value ωs has pulsation components proportional to the true motor rotational speed ωr, the pulsation order k, and the k-order angle detection error amplitude ak. When a conventional motor control device controls the speed of the motor 40 using a detected rotational speed value including these pulsation components, the output of a speed control unit that receives as input the deviation between the rotational speed command value and the detected rotational speed value. Since pulsations occur in the torque command value, motor torque pulsations occur. Then, as the rotational speed of the motor 40 increases, the pulsation component of the detected speed value becomes larger. Therefore, when the motor 40 rotates at high speed, the motor torque pulsation causes vibration noise, and even when the motor 40 is operating at low speed, if the natural frequency of the load connected to the motor 40 is low, , even if the pulsation frequency was low, vibration noise could be excited.

Therefore, when using a rotation angle sensor that detects a rotation angle that includes a pulsation component that is synchronized with the rotation angle of the motor 40, it is necessary to cancel the motor torque pulsation in calculating the angle and speed of the motor 40. Here, there is a position sensorless vector control technique in which rotation angle information of the motor 40 is estimated using a voltage applied to the motor 40 and a current flowing through the motor 40 without detecting the position by the rotation angle sensor 50. Therefore, in the following embodiment, the speed/angle calculation unit 20 according to the first embodiment, which can correct the error in the rotation angle detected by the rotation angle sensor 50, is configured by applying position sensorless vector control technology. do.

<Description of technology according to the first embodiment>
Next, an example of the internal configuration and operation of the speed/angle calculation section 20 according to the first embodiment will be described with reference to FIGS. 2 and 4.
FIG. 2 is a block diagram showing an example of the internal configuration of the speed/angle calculation section 20. As shown in FIG.

The speed/angle calculation section 20 is composed of an estimation processing section 21 and a calculation processing section 22.
The estimation processing section 21 includes an axis error estimation section 211 and an axis error estimation filter 212. This axis error estimating unit 211 estimates an axis error estimated value of the axis error of the motor 40 using the current and voltage applied to the motor 40.

The axis error estimation unit 211 calculates the d-axis voltage command value Vd* and the q-axis voltage command value Vq* output from the current control unit 104, and the d-axis current value Id and q output from the uvw/dq coordinate conversion unit 107. Based on the shaft current value Iq and the rotation speed ω estimated by the PI control unit 221 of the calculation processing unit 22, the angular error with respect to the actual rotation angle of the motor 40 is estimated as the shaft error. The angular error estimated by the axis error estimation unit 211 is output to the axis error estimation filter 212 as an axis error estimated value Δθe. When the motor 40 is a permanent magnet synchronous motor, the motor phase resistance is R, the d-axis inductance is Ld, the q-axis inductance is Lq, the d-axis interlinkage magnetic flux due to the permanent magnet is Ψd0, and the differential operator is p, then the formula ( The voltage equation using the extended induced voltage shown in 3) holds true.

By using the voltage equation of the extended induced voltage shown in equation (3), the error between the rotation angle θ of the d-axis that can be recognized by the motor control device 10 (controller) and the true rotation angle of the d-axis is calculated as the estimated axis error value. When Δθe, the following formula (4) holds true. The motor control device 10 recognizes the rotation angle θ input to the dq/uvw coordinate conversion unit 105 and the uvw/dq coordinate conversion unit 107. In other words, the angle information used when the motor control device 10 handles the rotational coordinate system is the "rotation angle of the d-axis recognized by the motor control device 10 (controller)."

Since Equation (4) is a differential equation regarding Δθe, calculation on a microcomputer is complicated. Furthermore, since equation (4) includes a differential term of the dq-axis current values, it is easily affected by noise. Therefore, if an approximation is performed assuming a steady state in which the differential values of the d-axis current Id, q-axis current Iq, and Δθe are 0, the following equation (5) with the differential term eliminated holds true.

Since equation (5) does not have a differential term, the microcomputer that controls the operation of the motor control device 10 calculates the motor phase resistance R, the d-axis inductance Ld, the q-axis inductance Lq, and the d-axis voltage command value Vd* and q. It can be easily calculated from only the axis voltage command value Vq* and the measured current value (d-axis current value Id and q-axis current value Iq). Therefore, the axis error estimating unit 211 according to the present embodiment can estimate the estimated axis error value Δθe of the rotation angle using equation (5). Note that the axis error estimation unit 211 is a function of a program that can be executed by a microcomputer.

When the axis error estimation unit 211 estimates the axis error estimated value Δθe using equation (5), instead of the d-axis voltage command Vd* and the q-axis voltage command Vq*, a line directly detected by a voltage sensor, etc. The d-axis voltage measurement value Vd and the q-axis voltage measurement value Vq obtained by coordinate transformation of the phase voltage or the phase voltage may be used. In this case, the influence of the output voltage error of the inverter 30, etc. can be eliminated, so that the accuracy of estimating the estimated axis error value Δθe by the axis error estimator 211 is improved.

In addition to equation (5), the axis error estimation unit 211 also uses a magnetic flux observer according to the characteristics of the motor 40 (including induction motors, synchronous reluctance motors, embedded magnet synchronous motors, surface magnet synchronous motors, etc.). It is also possible to use a method of estimating the axis error using , or a method of intentionally flowing current harmonics and estimating the axis error using motor saliency.

Next, an example of the operation of the axis error estimation filter 212 will be described.
The axis error estimation filter 212 selectively reduces the sixth-order component of the current frequency applied to the motor 40 from the axis error estimation value. For example, the axis error estimation filter 212 filters the axis error estimation value Δθe calculated by the axis error estimation unit 211, and converts the filtered axis error estimation value Δθef into an angle It is output to the detection error sampling section 224. This axis error estimation filter 212 can reduce components higher than the current frequency of the motor 40 from the axis error estimated value Δθe. The estimated axis error value Δθe output by the axis error estimation unit 211 contains many high frequency components such as noise components riding on the detected current of the current detection unit 31 and the sixth-order component of the current fundamental wave frequency caused by the dead time voltage error of the inverter. I'm here. Therefore, the axis error estimation filter 212 may be configured with a low-pass filter that cuts the noise component, a variable coefficient bandstop filter that selectively reduces the sixth-order component of the current fundamental frequency, or a filter that is a combination of these. desirable.

In addition, estimation error factors in position sensorless angle estimation using the voltage and current of the motor 40 include, for example, harmonic components of the motor induced voltage, offset and detection error of the current detection unit 31, fluctuations in dq-axis inductance due to magnetic saturation, Examples include rotation angle dependence of dq-axis inductance, change in motor phase resistance due to temperature change, and voltage drop due to ON resistance of power semiconductors of inverter 30. These factors mainly produce a DC offset component and a pulsation component of the first order or higher current frequency during position sensorless angle estimation. This is because the electrical characteristics of the motor 40 are symmetrical with respect to the electrical angle.

Therefore, in a multi-pole motor (for example, the motor 40) in which the main pulsation order of the rotation angle sensor 50 is a relatively low order of mechanical angle and the number of poles P is 20 or more, the detection error of the rotation angle sensor 50 is The pulsation frequency caused by this and the frequency higher than the first electrical angle that may occur in position sensorless angle estimation are separated in frequency. For this reason, the estimation processing unit 21 reduces the estimation error of the rotation angle in the position sensorless angle estimation by applying a low-pass filter or the like that cuts off the first-order or higher electrical angle to the estimated axis error value Δθe. The estimated axis error value Δθe can be accurately estimated from the rotation angle detected by the rotation angle 50.

Next, a configuration example of the calculation processing section 22 will be explained.
The calculation processing unit 22 includes a detection error correction unit 226 that corrects the detected rotation angle of the motor 40 based on the axis error estimated value estimated by the estimation processing unit 21, and corrects the detected rotation angle of the motor 40 based on the corrected detected rotation angle. Calculate the rotation speed and rotation angle of 40. For example, the calculation processing unit 22 calculates the rotation angle θ and rotation speed ω of the motor 40 after correcting the sensor detection error of the sensor detection angle θs input from the rotation angle sensor 50. The calculation processing section 22 includes a PI control section 221, an integration section 222, a mechanical angle conversion section 223, an angle detection error sampling section 224, a detection error component calculation section 225, and a sensor detection error correction section 226. .

First, the calculation unit 228 compares the rotation angle calculation value θ output from the integration unit 222 with the output from the sensor detection error correction unit 226 via the calculation unit 227, and determines the deviation Δθs.
The PI control unit 221 (an example of a rotation speed calculation unit) calculates the rotation speed based on the difference between the rotation angle and the detected rotation angle corrected by the detection error correction unit 226 based on the detection error component. For example, the PI control unit 221 calculates the rotational speed ω by performing proportional integration of the deviation Δθs. At this time, the PI control unit 221 controls the deviation Δθs to zero. The rotational speed ω calculated by the PI control unit 221 is compared with the rotational speed command ωr* input to the speed control unit 102 shown in FIG. is also output.

The integrating section 222 (an example of a rotation angle calculation section) calculates the rotation angle based on the rotation speed. For example, the integrating section 222 integrates the rotational speed ω to calculate the rotational angle calculation value θ. The rotation angle calculation value θ is output to the dq/uvw coordinate conversion unit 105 and the uvw/dq coordinate conversion unit 107 shown in FIG. It is compared with the output of the calculation unit 227. Therefore, the sensor detection angle θs is input to the sensor detection error correction unit 226 before entering the PI control unit 221, and the error in the sensor detection angle θs is corrected.

The mechanical angle conversion unit 223 converts the estimated axis error value into an estimated mechanical angle detection error value. For example, the mechanical angle conversion unit 223 divides the estimated axis error value Δθef output by the estimation processing unit 21 by the number of motor pole pairs P/2 (that is, multiplies it by 2/P) to obtain the estimated detection error value (mechanical angle) Δθm. Convert.

The angle detection error sampling unit 224 samples the waveform of the estimated mechanical angle detection error value converted by the mechanical angle conversion unit 223, and outputs angle detection error information. For example, the angle detection error sampling unit 224 samples the detection error estimation value (mechanical angle) Δθm converted into a mechanical angle for one rotation of the mechanical angle at equal intervals with respect to the sensor detection angle θs. According to the sampling theorem, the number of points Ns sampled by the angle detection error sampling section 224 needs to be at least twice the pulsation order of the main mechanical angle of the angle detection error of the rotation angle sensor 50. In order to improve the estimation accuracy of the phase angle of the pulsating component of the angle detection error using the method shown in FIG. It is desirable to set it to four times or more of the mechanical angle pulsation order.

The detection error component calculation unit 225 calculates, as a detection error component, the amplitude and phase of the spatial order of the angle detection error waveform obtained from the angle detection error information output by the angle detection error sampling unit 224. This detection error component includes the amplitude and phase of each pulsation order. When calculating the pulsation amplitude and phase of each order, the detection error component calculation unit 225 performs, for example, a discrete Fourier transform on the angle detection error information to calculate the detection error occurring in the detected rotation angle included in the angle detection error information. Calculate the amplitude and phase of the spatial order of the pulsation. At this time, by setting the number of sampling points Ns to a power of 2 (for example, 2 to the 4th power = 16), it becomes easier to apply the fast Fourier transform, thereby reducing the amount of calculation by the detection error component calculation unit 225. It becomes easier.

The sensor detection error correction unit 226 corrects the detected rotation angle based on the amplitude and phase of the spatial order. For example, the sensor detection error correction unit 226 converts the antiphase component of each pulsation order calculated by the detection error component calculation unit 225 into a sensor according to the current sensor detection angle θs output by the rotation angle sensor 50 shown in FIG. By superimposing it on the detection angle θs, the rotation synchronous pulsation component of the sensor detection angle θs is removed. This process corrects the error included in the current sensor detection angle θs. Then, the sensor detection error correction unit 226 outputs the current sensor detection angle θs with the error corrected to the calculation unit 227.

The calculation unit 227 outputs to the calculation unit 228 a calculation value obtained by multiplying the error-corrected sensor detection angle θs by the number of motor pole pairs P/2.
The calculation unit 228 compares the calculation value input from the calculation unit 227 and the calculated rotation angle value θ input from the integration unit 222, and calculates the deviation Δθs of the calculation value with respect to the calculated rotation angle value θ. The deviation Δθs is input to the PI control unit 221.

Next, the hardware configuration of the microcomputer 60 that constitutes the motor control device 10 will be explained.
FIG. 3 is a block diagram showing an example of the hardware configuration of the microcomputer 60. The microcomputer 60 is an example of hardware used as a computer that can operate as the motor control device 10 and the speed/angle calculation section 20 according to the present embodiment. The motor control device 10 according to the present embodiment realizes the calculation method performed by the functional units shown in FIGS. 1 and 2 in cooperation by the microcomputer 60 (computer) executing a program.

The microcomputer 60 includes a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62, and a RAM (Random Access Memory) 63, each connected to a bus 64. Furthermore, the microcomputer 60 includes a nonvolatile storage 65 and a network interface 66.

The CPU 61 reads software program codes that implement each function according to the present embodiment from the ROM 62, loads them into the RAM 63, and executes them. Variables, parameters, etc. generated during the calculation process of the CPU 61 are temporarily written in the RAM 63, and these variables, parameters, etc. are read out by the CPU 61 as appropriate. However, instead of the CPU 61, an MPU (Micro Processing Unit) may be used.

As the non-volatile storage 65, for example, an HDD (Hard Disk Drive), SSD (Solid State Drive), flexible disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, or non-volatile memory is used. It will be done. In addition to an OS (Operating System) and various parameters, programs for operating the microcomputer 60 are recorded in the nonvolatile storage 65. The ROM 62 and the non-volatile storage 65 record programs and data necessary for the CPU 61 to operate, and are examples of computer-readable non-transitory storage media that store programs executed by the microcomputer 60. used as.

For example, a NIC (Network Interface Card) is used as the network interface 66, and various data can be sent and received between devices via a LAN (Local Area Network), dedicated line, etc. connected to the terminal of the NIC. It is possible.

FIG. 4 is a flowchart showing an example of processing by the angle detection error sampling section 224 and the detection error component calculation section 225. The process shown in FIG. 4 is part of the motor control method performed by the motor control device 10. Here, an example of processing by the angle detection error sampling section 224 and the detection error component calculation section 225 when actually identifying a sensor detection error using a microcomputer or the like will be described.

First, the angle detection error sampling section 224 waits until the rotational speed of the motor 40 reaches a certain level or higher in order to improve the sampling accuracy of the angle detection error. Therefore, the angle detection error sampling section 224 calculates the calculated rotation speed ω after starting the identification of the sensor detection error. Then, the angle detection error sampling unit 224 determines whether the absolute value of the calculated rotational speed ω exceeds the angular frequency threshold ωc (S1). Here, the angular frequency threshold ωc represents a rotation speed threshold at which the angle detection error sampling section 224 starts sampling the angle detection error. If the angle detection error sampling unit 224 determines that the absolute value of the calculated rotational speed ω is equal to or less than the angular frequency threshold ωc (NO in S1), it repeats the determination process in step S1.

On the other hand, when the angle detection error sampling unit 224 determines that the absolute value of the calculated rotational speed ω exceeds the angular frequency threshold ωc (YES in S1), it starts angle detection error sampling (S2).

The estimated axis error value Δθe output from the axis error estimator 211 that calculates the angle detection error waveform is originally approximated by Expression (5), ignoring the differential term of the differential equation expressed by Expression (4). It is a value. Therefore, it is desirable to set the angular frequency threshold ωc near the final rotational speed command ωr* specified by the upper control system. In addition, the detection error component calculation unit 225 is configured using a method that depends on the voltage induced by the rotation of the motor 40, and the angle detection error sampled by the angle detection error sampling unit 224 is calculated using the method shown in equation (5). In order to calculate the error component, it is necessary to ensure the calculation accuracy of the angle detection error. Therefore, it is desirable that the angle detection error sampling section 224 sets the angular frequency threshold ωc to 10% or more of the motor rated rotational speed.

Next, the angle detection error sampling unit 224 determines whether sampling of the angle detection error waveform for one round of mechanical angle has been completed (S3). If sampling for one round of mechanical angle has not been completed (NO in S3), the angle detection error sampling unit 224 continues the process in step S2 again. On the other hand, if sampling for one round of mechanical angle has been completed (YES in S3), the angle detection error sampling unit 224 outputs angle detection error information.

The detection error component calculation unit 225 calculates the error component based on the angle detection error information (S4), and ends this process. As described above, for example, discrete Fourier transform can be used to calculate the error component.

In the motor control device 10 according to the first embodiment described above, the angle detection error pulsation of the rotation angle sensor 50 is estimated by the sensorless estimated rotation angle when the motor 40 is operated at medium to high speed, and the angle detection error pulsation of the rotation angle sensor 50 is estimated based on the estimated angle detection error information. Correct the sensor detection angle θs. Therefore, it is possible to control the motor 40 without being affected by the angle detection error of the rotation angle sensor 50, and to prevent vibration noise of the motor 40. In particular, the motor control device 10 drives the motor 40 by correcting the pulsation component that varies depending on the rotation angle detected by the rotation angle sensor 50, thereby reducing vibration and noise in various devices driven by the motor 40. be able to.

Identification of the sensor detection error by the calculation processing unit 22 described above can be performed at any timing even when the motor 40 is connected to a load and is being operated. For example, when the detection error characteristics of the rotation angle sensor 50 change due to a temperature change, the calculation processing unit 22 repeats the above described process at a sufficiently short period relative to the temperature rise due to heat generation of the motor 40 or the time change rate of periodic environmental temperature change. Execute the identification process. By the calculation processing unit 22 repeatedly performing the sensor detection error identification process, vibration noise originating from the rotation angle sensor 50 can be prevented even if the characteristics of the rotation angle sensor 50 change.

Furthermore, even when the installation status of the rotation angle sensor 50 changes due to a change in the installation position of the motor 40, etc., the calculation processing unit 22 automatically corrects the detection error by executing the above identification process. Can be done. By configuring the calculation processing unit 22 as shown in FIG. 2, the rotation synchronous pulsation component of the rotation angle sensor 50 can be removed, and vibration noise originating from the rotation angle sensor 50 can be prevented.

[Second embodiment]
Next, a configuration example and an operation example of the speed/angle calculation section 20A according to the second embodiment of the present invention will be described with reference to FIG. 5.
FIG. 5 is a block diagram showing a configuration example of a speed/angle calculation section 20A according to the second embodiment. The speed/angle calculation unit 20A replaces the speed/angle calculation unit 20 included in the motor control device 10 according to the first embodiment shown in FIG. The speed/angle calculation unit 20A according to the second embodiment has a function of outputting the rotation speed and angle detected by the rotation angle sensor 50 and the rotation speed and angle estimated without a position sensor.

The configuration examples and operation examples of the functional units other than the speed/angle calculation unit 20A in the motor control device 10 are the same as those in the first embodiment, and therefore description thereof will be omitted. A speed/angle calculation section 20A according to the second embodiment includes an estimation processing section 21A and a calculation processing section 22A. The estimation processing section 21A includes a PI control section 213 and an integration section 214 in addition to the axis error estimation section 211 and the axis error estimation filter 212 included in the estimation processing section 21 according to the first embodiment.

The PI control unit 213 (an example of a rotational speed estimation unit) estimates the estimated rotational speed based on the estimated axis error value. For example, the PI control unit 213 performs position sensorless speed estimation so that the output of the axis error estimation filter 212 becomes zero. Therefore, the PI control unit 213 calculates the position sensorless estimated speed ωe (electrical angle) by performing proportional integration of the estimated axis error value Δθef output from the axis error estimation filter 212. The position sensorless estimated speed ωe (electrical angle) is output to the axis error estimation section 211, the axis error estimation filter 212, the integration section 214, and the mechanical angle estimation integration section 223A of the calculation processing section 22A. Further, when the rotation angle sensor 50 fails, the position sensorless estimated speed ωe (electrical angle) is used by the speed control section 102 and the current control section 104 shown in FIG.

The integrating unit 214 (an example of a rotation angle estimation unit) estimates the estimated rotation angle based on the estimated rotation speed. For example, the integrating unit 214 integrates the position sensorless estimated speed ωe (electrical angle) to calculate the position sensorless estimated angle θe (electrical angle). Further, when the rotation angle sensor 50 is out of order, the position sensorless estimated angle θe (electrical angle) is output to the dq/uvw coordinate conversion unit 105 and the uvw/dq coordinate conversion unit 107.

Further, the calculation processing section 22A of the speed/angle calculation section 20A according to the second embodiment includes a mechanical angle estimation integration section 223A.
The mechanical angle estimation and integration unit 223A (an example of a conversion unit) converts the integrated estimated rotational speed into an estimated mechanical angle rotation angle. For example, the mechanical angle estimation and integration unit 223A uses the position sensorless estimated speed ωe (electrical angle) calculated by the PI control unit 213 to calculate the position sensorless estimated angle θm (mechanical angle).

Generally, in position sensorless angle estimation using the voltage and current applied to the motor 40, an electrical angle is calculated. The calculation processing unit 22 according to the present embodiment sets the initial value of the mechanical angle estimation and integration unit 223A to the measured value of the mechanical angle obtained from the rotation angle sensor 50 in order to estimate the mechanical angle. Then, the mechanical angle estimation integration unit 223A calculates the position sensorless estimated angle θm (mechanical angle) without using a position sensor.

The detection error calculation unit 229 compares the estimated rotation angle of the mechanical angle and the detected rotation angle, and calculates the detection error difference between the estimated rotation angle of the mechanical angle and the detected rotation angle. For example, the detection error calculation unit 229 compares the sensor detection angle θs of the rotation angle sensor 50 and the position sensorless estimated angle θm (mechanical angle), and calculates the detection error estimated value (mechanical angle) Δθm as the detection error difference. do. This detection error estimated value (mechanical angle) Δθm is input to the angle detection error sampling section 224.

The angle detection error sampling section 224 samples the waveform of the detection error difference and outputs angle detection error information. For example, the angle detection error sampling unit 224 samples one rotation of the mechanical angle at equal intervals with respect to the sensor detection angle θs of the rotation angle sensor 50, except for the detection error estimated value (mechanical angle) Δθm, which is the detection error difference. .

Then, the detection error component calculation unit 225 calculates the detection error component included in the detected rotation angle based on the angle detection error information. For example, the detection error component calculation section 225 calculates the amplitude and phase of each pulsation order based on the angle detection error information sampled by the angle detection error sampling section 224, and the sensor detection error correction section 226 calculates the amplitude and phase of each pulsation order. The rotation synchronous pulsation component of is removed.

The speed/angle calculation unit 20A according to the second embodiment described above can calculate the rotation angle and rotation speed without using any position sensor other than the rotation angle sensor 50. Therefore, the motor control device 10 including the speed/angle calculation section 20A shifts to position sensorless control when a failure of the rotation angle sensor 50 occurs. Then, the motor control device 10 continues to control the motor 40 using the position sensorless estimated speed ωe and the position sensorless estimated angle θe (electrical angle), and can ensure redundancy of the motor control device 10.

[Third embodiment]
Next, a configuration example and an operation example of the speed/angle calculation section 20B according to the third embodiment of the present invention will be described with reference to FIG. 6.
FIG. 6 is a block diagram showing a configuration example of the speed/angle calculation section 20B according to the third embodiment. The speed/angle calculation unit 20B replaces the speed/angle calculation unit 20 included in the motor control device 10 according to the first embodiment shown in FIG. The speed/angle calculation unit 20B according to the third embodiment has a function of calculating the rotation speed and angle by switching between the rotation speed detected by the rotation angle sensor 50 and the rotation speed estimated without a position sensor. .

The configuration examples and operation examples of the functional units other than the speed/angle calculation unit 20B in the motor control device 10 are the same as those in the first embodiment, and therefore the description thereof will be omitted. The estimation processing section 21 of the speed/angle calculation section 20B according to the third embodiment has the same configuration as the estimation processing section 21 according to the first embodiment.
The axis error estimation value Δθef output from the axis error estimation filter 212 is output to the switching unit 230 of the calculation processing unit 22B.

The calculation processing unit 22B of the speed/angle calculation unit 20B according to the third embodiment includes a switching unit 230 in addition to each functional unit included in the calculation processing unit 22A according to the second embodiment. The calculation processing unit 22B calculates the rotation speed and rotation angle based on the estimated axis error value or the calculated axis error value switched by the switching unit 230. This calculation processing section 22B has a configuration in which the PI control section 213 and the integration section 214 of the calculation processing section 22A according to the second embodiment are integrated into a PI control section 221 and an integration section 222.

The switching unit 230 switches to either the axis error estimated value estimated by the estimation processing unit 21 or the axis error calculation value calculated by the detection error correction unit 226 based on the detected rotation angle. For example, the switching unit 230 has a difference Δθs (axis error calculation (an example of a value) and a switching signal from a higher-level control system are input. Based on the switching signal, the switching unit 230 switches the signal output to the PI control unit 221 to either the estimated axis error value Δθef or the deviation Δθs of the calculated rotation angle value θ.

The mechanical angle estimation and integration unit 223A (an example of a conversion unit) converts the rotational speed ω calculated by the PI control unit 221 by integrating the estimated axis error value Δθef or the deviation Δθs of the calculated rotational angle value θ into the rotational angle θm of the mechanical angle. Convert.
The detection error calculation unit 229 compares the mechanical angle rotation angle θm and the detected rotation angle θs to calculate a detection error difference between the mechanical angle rotation angle θm and the detected rotation angle θs.
The angle detection error sampling section 224 samples the waveform of the detection error difference and outputs angle detection error information.
The detection error component calculation unit 225 calculates a detection error component included in the detected rotation angle based on the angle detection error information.

The PI control unit 221 calculates the rotation speed ω based on either the estimated axis error value Δθef or the deviation Δθs of the calculated rotation angle value θ, which is switched and outputted by the switching unit 230.
The integrating section 222 integrates the calculated rotational speed ω and outputs it as a calculated rotational angle value θ.

In the speed/angle calculation section 20B according to the third embodiment described above, the number of PI control sections and integration sections can be reduced compared to the speed/angle calculation section 20A according to the second embodiment. Therefore, it is possible to reduce the processing amount and memory usage of the microcomputer that implements the functions of the speed/angle calculation section 20B.

Furthermore, the switching unit 230 switches the rotation angle deviation output to the PI control unit 221 to either the estimated axis error value Δθef or the deviation Δθs of the calculated rotation angle value θ. For this reason, the motor control device 10 uses the rotational speed ω and the rotational angle θ calculated from the rotational angle deviation appropriate for controlling the motor 40.

[Fourth embodiment]
Next, a configuration example and an operation example of an elevator apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. 7.
FIG. 7 is a schematic configuration diagram showing an example of the overall configuration of an elevator device 300 according to the fourth embodiment. The elevator device 300 according to the present embodiment includes the motor control device 10 having the speed/angle calculating section according to any one of the first to third embodiments described above.

In the elevator device 300, a car 303 is connected to one end of the main rope 306, and a counterweight 304 is connected to the other end of the main rope 306. The main rope 306 is wound around the sheave 307 and direction change pulley 305 of the hoist 301 . As a result, the car 303 and the counterweight 304 are suspended within the hoistway 302.

The hoisting machine 301 is configured by an inverter 30, a motor 40, a sheave 307, a rotation angle sensor 50, and an electromagnetic brake 308.

A main rope 306 is wound around the sheave 307 to raise and lower the car 303. The motor 40 included in the hoisting machine 301 is drive-controlled by the motor control device 10 and the inverter 30, and rotates the sheave 307. The rotation of the sheave 307 causes the main rope 306 to be driven by the sheave 307 . As a result, the car 303 and the counterweight 304 move up and down in vertically opposite directions within the hoistway 302. The car 303 moves while being guided by a car guide rail (not shown), and the counterweight 304 also moves vertically while being guided by a counterweight guide rail (not shown). The motor control device 10 executes the processes of the estimation processing section 21 and the calculation processing section 22 according to the first to third embodiments described above during an operating state in which the car 303 is moving up and down.

When stopping the car 303, an electromagnetic brake 308 provided in the hoisting machine 301 brakes the rotation of the hoisting machine 301. As the electromagnetic brake 308, for example, a disc type electromagnetic brake is applied. In this embodiment, the hoisting machine 301 is configured to include one electromagnetic brake 308, but may be configured to include a plurality of electromagnetic brakes 308. With this configuration, the plurality of electromagnetic brakes 308 can constitute a multi-system brake by operating simultaneously.

In the elevator device 300, a plurality of natural vibration modes exist in the vicinity of several Hz to several tens of Hz due to the elasticity of the main rope 306, etc. Therefore, when the motor torque pulsation frequency of the hoisting machine 301 matches the above-mentioned natural vibration mode, vertical vibrations are excited in the car 303, deteriorating the passenger comfort. Therefore, if the rotation angle sensor 50 has an angle detection error, this may deteriorate the ride comfort.

In this embodiment, deterioration of ride comfort is suppressed or prevented by correcting the angle detection error Δθe using the method according to the first to third embodiments. Gearless hoisting machines, which have become mainstream in recent years, often have a multi-pole structure with 20 or more motor poles in order to obtain large torque with a small size. Therefore, using the methods according to the first to third embodiments is suitable for correcting sensor detection errors in position sensorless angle estimation.

The elevator device 300 loads passengers into a car 303 at a plurality of elevator stops 310 provided on arbitrary floors of the building 330. Thereafter, in the elevator device 300, the motor control device 10 controls the rotational speed of the motor 40 according to the speed command output by the elevator control device 320, and the car 303 is stopped at the elevator landing 310 of the target floor, thereby transporting passengers. transport. At this time, if the departure floor and the destination floor are sufficiently far apart, there is a constant speed section in which the speed command output by the elevator control device 320 and the rotational speed of the motor 40 are constant.

When the motor control device 10 controls the hoisting machine 301 using different speed patterns, the torque required by the hoisting machine 301 is mainly the sum of the following three types of torque.
(1) Torque for accelerating and decelerating the mass of the car 301, counterweight 304, and main rope 306, and the rotational inertia of the hoist 301 and direction change pulley 305 (referred to as "acceleration/deceleration torque")
(2) Torque to balance the difference in gravity applied to the car 301, the counterweight 304, and the main rope 306 (referred to as "balance torque")
(3) Friction between the car 301 or counterweight 304 and the guide rail, bearing loss of the sheave 307 and direction change pulley 305, and deformation of the main rope 306 by the sheave 307 and direction change pulley 305. (referred to as “running loss torque”)

In the constant speed section, the acceleration/deceleration torque becomes 0, so only the balance torque and running loss torque become the output torque of the hoist 301. Further, when the car 303 is running after a passenger is loaded into the car 303, since the mass of the car 303 is constant, the balancing torque can also be considered to be approximately constant. Furthermore, if the rotational speed is constant, the running loss torque can also be considered to be approximately constant.

Therefore, in the constant speed section, the rotational speed and torque of the motor 40 are approximately constant. Therefore, in the position sensorless angle detection error estimation using equation (5) etc., a steady state is assumed in which the differential value of the d-axis current Id of the motor 40, the q-axis current Iq, and the estimated axis error value Δθe is 0. The calculation formula is approximated. Therefore, if the rotation speed and torque are constant, the accuracy of estimating the rotation angle calculation value θ is improved. Therefore, the timing for identifying the sensor detection error of the rotation angle sensor 50 is preferably during the constant speed section.

While the elevator device 300 continues to operate, for example, by identifying sensor detection errors every time a constant speed section occurs, maintenance-free and continuous operation can be performed against changes in angle detection error characteristics due to changes in sensor characteristics or surrounding environment. It is possible to perform effective correction.

[Modified example]
Note that the type of motor 40 shown in FIG. 1 may be an induction motor. Furthermore, instead of the inverter 30, an AC voltage source that can output any voltage may be used. Further, the elevator device 300 according to the fourth embodiment may be a so-called machine room-less elevator in which a hoisting machine and an elevator control device are installed in a hoistway.

Furthermore, the motor control device 10 and the speed/ angle calculating sections 20, 20A, and 20B according to the first to third embodiments may be used in a conveyance device such as a belt conveyor, in addition to the elevator device 300.

The present invention is not limited to the embodiments described above, and it goes without saying that various other applications and modifications can be made without departing from the gist of the present invention as set forth in the claims.
For example, in each of the embodiments described above, the configurations of devices and systems are explained in detail and specifically in order to explain the present invention in an easy-to-understand manner, and the embodiments are not necessarily limited to having all the configurations described. Further, it is possible to replace a part of the configuration of the embodiment described here with the configuration of another embodiment, and furthermore, it is also possible to add the configuration of another embodiment to the configuration of a certain embodiment. Furthermore, it is also possible to add, delete, or replace some of the configurations of each embodiment with other configurations.
Further, the control lines and information lines are shown to be necessary for explanation purposes, and not all control lines and information lines are necessarily shown in the product. In reality, almost all components may be considered to be interconnected.

DESCRIPTION OF SYMBOLS 1... Motor control system, 10... Motor control device, 20... Speed/angle calculation part, 21... Estimation processing part, 22... Calculation processing part, 30... Inverter, 31... Current detection part, 40... Motor, 50... Rotation angle Sensor, 211... Axis error estimation section, 212... Axis error estimation filter, 221... PI control section, 222... Integration section, 223... Mechanical angle conversion section, 223A... Mechanical angle estimation integration section, 224... Angle detection error sampling section, 225...Detection error component calculation unit, 226...Sensor detection error correction unit, 227...Calculation unit, 228...Calculation unit, 300...Elevator device

Claims (13)

1. A motor control device that controls the motor based on the rotation speed and rotation angle of the motor,
   an estimation processing unit including an axis error estimation unit that estimates an axis error estimated value of an axis error of the motor using the voltage and current applied to the motor and the rotational speed of the motor;
   a detection error correction unit that corrects the detected rotation angle of the motor based on the estimated axis error value, and calculates the rotation speed and the rotation angle of the motor based on the corrected detected rotation angle; A motor control device comprising a processing section.
2. The calculation processing unit is
   a conversion unit that converts the estimated axis error value into an estimated mechanical angle detection error value;
   a sampling unit that samples a waveform of the estimated detection error value of the mechanical angle and outputs angle detection error information;
   a detection error component calculation unit that calculates a detection error component included in the detected rotation angle based on the angle detection error information;
   a rotation speed calculation unit that calculates the rotation speed based on a difference between the rotation angle and the detected rotation angle corrected by the detection error correction unit based on the detection error component;
   The motor control device according to claim 1, further comprising: a rotation angle calculation unit that calculates the rotation angle based on the rotation speed.
3. The estimation processing unit is
   a rotational speed estimation unit that estimates an estimated rotational speed based on the estimated axis error value;
   The motor control device according to claim 1, further comprising: a rotation angle estimator that estimates an estimated rotation angle based on the estimated rotation speed.
4. The calculation processing unit is
   a conversion unit that converts the integrated estimated rotation speed into an estimated rotation angle in mechanical angle;
   a detection error calculation unit that compares the estimated rotation angle of the mechanical angle and the detected rotation angle to calculate a detection error difference of the detected rotation angle with respect to the estimated rotation angle of the mechanical angle;
   a sampling unit that samples the waveform of the detection error difference and outputs angle detection error information;
   a detection error component calculation unit that calculates a detection error component included in the detected rotation angle based on the angle detection error information;
   a rotation speed calculation unit that calculates the rotation speed based on a difference between the rotation angle and the detected rotation angle corrected by the detection error correction unit based on the detection error component;
   The motor control device according to claim 3, further comprising: a rotation angle calculation unit that calculates the rotation angle based on the rotation speed.
5. The calculation processing unit includes a switching unit that switches to either the axis error estimated value estimated by the estimation processing unit or the axis error calculation value calculated by the detection error correction unit based on the detected rotation angle. The motor control device according to claim 1 , wherein the rotation speed and the rotation angle are calculated based on the estimated axis error value or the calculated axis error value switched by the switching unit.
6. The calculation processing unit is
   a conversion unit that converts the integrated rotational speed into a mechanical rotation angle;
   a detection error calculation unit that compares the rotation angle of the mechanical angle and the detected rotation angle to calculate a detection error difference of the detected rotation angle with respect to the rotation angle of the mechanical angle;
   a sampling unit that samples the waveform of the detection error difference and outputs angle detection error information;
   a detection error component calculation unit that calculates a detection error component included in the detected rotation angle based on the angle detection error information;
   a rotational speed calculation unit that calculates the rotational speed based on either the estimated axis error value or the calculated axis error value that is switched and input by the switching unit;
   The motor control device according to claim 5, further comprising: a rotation angle calculation unit that calculates the rotation angle based on the rotation speed.
7. The detection error component calculation unit calculates the amplitude and phase of the spatial order of the angle detection error waveform obtained from the angle detection error information as the detection error component,
   The motor control device according to claim 2, wherein the detection error correction section corrects the detected rotation angle based on the amplitude and phase of the spatial order.
8. The detection error component calculation unit performs a discrete Fourier transform on the angle detection error information to calculate the amplitude and phase of the spatial order of the detection error pulsation occurring in the detected rotation angle, which is included in the angle detection error information. The motor control device according to claim 7.
9. The motor control device according to claim 2, wherein the estimation processing unit includes a filter that selectively reduces a sixth-order component of a frequency of a current applied to the motor from the estimated axis error value.
10. The motor control device according to claim 9, wherein the filter reduces a component higher than the current frequency of the motor from the estimated axis error value.
11. A motor control method performed by a motor control device that controls the motor based on the rotation speed and rotation angle of the motor, the method comprising:
    a process of estimating an estimated axis error value of an axis error of the motor using the voltage and current applied to the motor and the rotational speed of the motor;
    a process of correcting a detected rotation angle of the motor based on the estimated axis error value;
    A motor control method, comprising: calculating the rotational speed and the rotational angle of the motor based on the corrected detected rotational angle.
12. A car that moves up and down a hoistway, a main rope connected to the car, a sheave around which the main rope is wound to move the car up and down, a motor that drives the sheave, and a motor that drives the sheave. a motor control device that controls the motor based on a rotation speed and a rotation angle,
    The motor control device includes:
    an estimation processing unit including an axis error estimation unit that estimates an axis error estimated value of an axis error of the motor using the voltage and current applied to the motor and the rotational speed of the motor;
    a detection error correction unit that corrects the detected rotation angle of the motor based on the estimated axis error value, and calculates the rotation speed and the rotation angle of the motor based on the corrected detected rotation angle; An elevator device having a processing section.
13. The elevator apparatus according to claim 12, wherein the processing of the estimation processing section and the calculation processing section is executed during an operating state in which the car is ascending and descending.

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