JP6658023B2 - Automatic current command table generation system and current command table automatic generation method for embedded magnet synchronous motor - Google Patents

Description

  The present invention relates to a current command table automatic generation system for an interior permanent magnet synchronous motor (IPMSM), and a torque command value (torque generated from a speed controller) in an inverter that controls the motor at a variable speed. The present invention relates to a technique for automatically generating a table for realizing high-precision and high-efficiency conversion from a torque command value to a vector control d-axis and q-axis current command value when torque control is performed by giving a command value.

  An embedded magnet synchronous motor can utilize reluctance torque using magnetic saliency in addition to magnet torque due to permanent magnets. It is generally known that torque can be maximized by appropriately controlling the current phase by an inverter.

  For example, when performing current vector control in the rotating coordinate system of a three-phase inverter, the d-axis is defined in the direction of the N pole of the permanent magnet, and the q-axis is defined as a phase advanced by 90 degrees from the d-axis. The current vector (amplitude and phase) can be determined by controlling the ratio of the following to an arbitrary value.

  Non-Patent Document 1 describes theoretical contents of a method for determining a current phase (a ratio between a d-axis current and a q-axis current), such as maximum torque / current control, maximum efficiency control, and maximum torque / magnetic flux control. ing. Generally, based on such a theoretical formula, a current phase corresponding to the operating state of the rotational speed and the torque is determined, and is often implemented as a table map in the inverter program.

Yoji Takeda et al., "Design and Control of Interior Permanent Magnet Synchronous Motor," Ohmsha, 2001.10.

  However, since the parameters of the actual motor have errors from the design values, in order to determine the current phase with higher accuracy, it is conceivable to correct the table map based on the actually measured values. In addition, the responsiveness of the inverter that drives the motor, the current sensor used for feedback control, the dead time associated with digital control, and the like also become error factors in determining the optimal current phase.

  On the other hand, when a table map is generated or corrected based on actual measurement values, there is a problem that it takes time to generate and adjust the table. In particular, when an adjustment operator manually generates a table while checking actual measured values, a great deal of time and effort is required, and the accuracy of the table also depends on the skill of the adjustment operator.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an embedded magnet synchronous motor capable of automatically and accurately generating d-axis / q-axis current command values based on actually measured values. It is an object of the present invention to provide a system and method for automatically generating a current command table of a permanent magnet synchronous motor.

The current command table automatic generation system for an embedded magnet synchronous motor according to claim 1 for solving the above-mentioned problem, comprises: a torque command given to an inverter that controls a variable speed of the embedded magnet synchronous motor; A system for automatically generating a current command table for converting to a q-axis current command value,
A load device that is connected to the motor through a shaft and that performs servo motor control;
A torque meter installed on the coupling shaft of the load device and the motor,
The rotational speed and torque of the motor are each divided into a predetermined rotational speed range and a torque range, and each of the divided ranges is set to a speed command value and a torque command value at one operating point, respectively.
The rotational speed of the load device, the speed control to the load device so as to be a speed command value set at the one operating point,
A q-axis current command value generation process for generating a q-axis current command value by performing a torque feedback control so that the torque detection value of the torque meter matches the torque command value set at the one operating point is executed. ,
While the torque feedback control at the one operating point is being performed, a d-axis current command value that is generated by searching for a d-axis current command value that satisfies a desired performance based on various information of the current command table automatic generation system. Execute the generation process,
The generation processing of the d-axis current command value and the q-axis current command value is performed for all operating points,
A d-axis current command value and a q-axis current command value generated for all of the operating points, a current command table automatic adjustment device that creates a table in association with the rotation speed and the torque,
An inverter control unit that controls the inverter based on the generated d-axis current command value and q-axis current command value;
It is characterized by having.

A method of automatically generating a current command table for an embedded magnet synchronous motor according to claim 17, wherein the load device is connected to the embedded magnet synchronous motor by a shaft and controlled by a servo motor; A current command table automatic generation system having a torque meter installed in the motor and an inverter for controlling the motor at a variable speed. The torque command given to the inverter is converted into d-axis and q-axis current command values for vector control. A method for automatically generating a current command table to perform,
A current command table automatic adjusting device divides the rotation speed and the torque of the motor into a predetermined rotation speed range and a torque range, and sets each of the divided ranges to a speed command value and a torque command value at one operating point. Command value setting step;
A speed control step of causing the load device to perform speed control such that the current command table automatic adjusting device performs a speed command value set at the one operating point, the rotational speed of the load device;
The current command table automatic adjusting device performs a torque feedback control so as to match a torque detection value of the torque meter with a torque command value set at the one operating point, and generates a q-axis current command value. A current command value generation step;
The current command table automatic adjustment device searches for a d-axis current command value that satisfies the desired performance based on various information of the current command table automatic generation system while the torque feedback control at the one operating point is being performed. D-axis current command value generating step of generating
A step for the current command table automatic adjusting device to repeatedly execute the command value setting step, the speed control step, the q-axis current command value generation step, and the d-axis current command value generation step for all operating points;
A step of the current command table automatic adjusting device tabulating the d-axis current command value and the q-axis current command value generated for the all operating points with the rotation speed and the torque, respectively,
It is characterized by having.

  According to the above configuration, torque feedback control is performed in the q-axis current command value generation processing, and the torque feedback control is performed according to a change in the d-axis current command value when searching for the d-axis current command value in the d-axis current command value generation processing. Since the torque feedback control is effective for the generated torque, the q-axis current command value is automatically adjusted so as to always match the torque command value.

  For this reason, while maintaining the state in which the q-axis current is automatically controlled by the torque feedback control, an optimum d-axis current command value for improving the efficiency is searched for. As a result, it is possible to automatically generate a current command table that enables the conversion from the torque command value to the d-axis current command value and the q-axis current command value of the embedded magnet synchronous motor with high accuracy and high efficiency.

  In addition, in the current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 2, the d-axis current command value generation process according to claim 1 changes the d-axis current command value, It is characterized in that the current amplitude value of the detected motor current is observed, and a d-axis current command value at which the current amplitude value is minimized is searched for.

  According to the above configuration, the d-axis current command value and the q-axis current command value that can obtain the maximum torque with the minimum current amplitude can be determined by the maximum torque / current control method. For this reason, the d-axis current command value and the q-axis current command value that minimize the copper loss of the interior permanent magnet synchronous motor can be generated.

According to a third aspect of the present invention, the automatic current command table adjusting device calculates a current amplitude value of the motor current from the d-axis current command value. ,
The d-axis current command value generation process changes the d-axis current command value, observes the calculated current amplitude value before and after the change, and searches for a d-axis current command value that minimizes the current amplitude value. It is characterized by:

  According to the above configuration, since it is not necessary to detect the motor current and take in the detection signal, the number of signals between the motor current table automatic adjustment device and the calculation inside the inverter is simplified.

  According to a fourth aspect of the present invention, in the current command table automatic generation system for an interior permanent magnet synchronous motor according to the first aspect, the d-axis current command value generation process includes changing the d-axis current command value, and changing the inverter before and after the change. And searching for a d-axis current command value at which the input power is minimized.

  According to the above configuration, the d-axis current command value and the q-axis current command value that can obtain the maximum torque with the minimum power consumption (input power to the inverter) can be determined by the maximum efficiency control method. Therefore, it is possible to generate the d-axis current command value and the q-axis current command value that minimize the total loss such as the iron loss and the copper loss of the interior permanent magnet synchronous motor.

Further, in the current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 5, the inverter control unit according to claim 1, wherein the inverter control unit performs d-axis current and q-axis current obtained by coordinate-transforming a three-phase detection current of the inverter. Is a voltage command duty ratio from the d-axis voltage command value, the q-axis voltage command value obtained by performing tracking control so as to match the d-axis current command value, the q-axis current command value, and the DC input voltage of the inverter. Calculate,
The d-axis current command value generation process changes the d-axis current command value, observes the voltage command duty ratio before and after the change, and searches for a d-axis current command value at which the voltage command duty ratio becomes a set limit value. It is characterized by doing.

  According to the above configuration, the d-axis current command value and the q-axis current command value that can obtain the maximum torque with the minimum magnetic flux (induced voltage) can be determined by the maximum torque / magnetic flux control (induced voltage control) method. Therefore, it is possible to generate a d-axis current command value and a q-axis current command value that minimize the iron loss of the interior permanent magnet synchronous motor.

According to a sixth aspect of the present invention, there is provided an automatic current command table generation system for an interior permanent magnet synchronous motor according to any one of the first to fifth aspects, which is prepared by measuring a no-load loss of the motor in advance. A no-load loss table that outputs a load loss torque corresponding to the speed command value set at the three operating points,
The q-axis current command value generation process is a process in which a torque detection value of the torque meter is a torque obtained by adding a torque command value set at the one operating point and a no-load loss torque output from the no-load loss table. It is characterized in that a q-axis current command value is generated by performing torque feedback control so as to match.

Also, in the method of automatically generating a current command table for an interior permanent magnet synchronous motor according to claim 18, the automatic current command table adjusting device according to claim 17 measures the no-load loss of the motor in advance and performs the one operation. A step of creating a no-load loss table in which a load loss torque corresponding to the speed command value set at the point is output,
The q-axis current command value generation step is a step in which a torque detection value of the torque meter is a torque obtained by adding a no-load loss torque output from the no-load loss table and a torque command value set at the one operating point. It is characterized in that a q-axis current command value is generated by performing torque feedback control so as to match.

  According to the above configuration, it is possible to generate the current command table after preliminarily compensating for the torque reduced by no-load loss such as mechanical loss.

An automatic current command table generation system for an interior permanent magnet synchronous motor according to claim 7 is provided in the automatic current command table adjusting device according to claim 1, wherein the current amplitude of the motor current exceeds the current amplitude limit value. A current amplitude limit processing unit that performs a current amplitude limit process for limiting the d-axis current command value and the q-axis current command value when the current amplitude exceeds the current amplitude limit value, or the inverter control The d-axis current and the q-axis current, which are coordinate-converted from the three-phase detection current of the inverter, are controlled to follow the d-axis current command value and the q-axis current command value. An axis voltage command value is obtained, and it is determined whether or not the voltage amplitudes of the d-axis voltage command value and the q-axis voltage command value exceed the voltage amplitude limit value, and when the voltage amplitude exceeds the voltage amplitude limit value, the d-axis voltage Command value, limited to q-axis voltage command value Voltage amplitude limitation processing unit performing voltage amplitude limiting process of applying comprises at least one of,
The d-axis current command value generation processing is performed in a state where at least one of the current amplitude or the voltage amplitude exceeds the limit value in a state where the torque feedback control is being performed at the one operating point. A d-axis current command value capable of executing the first search mode and performing the maximum output control based on a torque error indicating a deviation between the torque detection value and the torque command value as the information of the current amplitude or the voltage. When at least one of the amplitudes is equal to or less than the limit value, the d-axis current command value at which the maximum efficiency control can be performed by executing the second search mode based on the second information of the current command table automatic generation system. It is characterized by generating.

A method for automatically generating a current command table for an interior permanent magnet synchronous motor according to claim 19 is provided in the automatic current command table adjusting device according to claim 17, wherein the current amplitude of the motor current exceeds the current amplitude limit value. A current amplitude limit processing unit that performs a current amplitude limit process for limiting the d-axis current command value and the q-axis current command value when the current amplitude exceeds the current amplitude limit value, or an inverter control unit The d-axis current and the q-axis current are controlled so that the d-axis current and the q-axis current obtained by coordinate-converting the three-phase detection current of the inverter coincide with the d-axis current command value and the q-axis current command value. A voltage command value is obtained, and it is determined whether or not the voltage amplitudes of the d-axis voltage command value and the q-axis voltage command value exceed the voltage amplitude limit value, and when the voltage amplitude exceeds the voltage amplitude limit value, the d-axis voltage command Value or q-axis voltage command value Voltage amplitude limitation processing unit for performing the voltage amplitude limitation process that comprises at least one of,
The d-axis current command value generation step includes a step of: when at least one of the current amplitude or the voltage amplitude exceeds the limit value in a state where the torque feedback control is being performed at the one operating point, A d-axis current command value capable of executing the first search mode and performing the maximum output control based on a torque error indicating a deviation between the torque detection value and the torque command value as the information of the current amplitude or the voltage. When at least one of the amplitudes is equal to or less than the limit value, the d-axis current command value at which the maximum efficiency control can be performed by executing the second search mode based on the second information of the current command table automatic generation system. It is characterized by generating.

  According to the above configuration, the current command table generation method of the control method suitable for each operation region of the maximum efficiency control and the maximum output control can be appropriately switched according to the presence / absence of the current / voltage limitation of the inverter.

  Further, in the system for automatically generating a current command table for an interior permanent magnet synchronous motor according to claim 8, the automatic current command table adjusting device according to claim 7, wherein the data when the first or second search mode is executed. A convergence determination process for determining whether or not the convergence to the minimum point is performed, and when performing the first or second search mode, if the first or second search mode repeatedly transitions, the number of times of the state transition And the convergence determination process is performed based on the duration.

  According to the above configuration, even when the first or second search mode repeatedly makes a state transition, the data at the time of executing the mode can be made to converge.

  According to a ninth aspect of the present invention, in the current command table automatic generation system for an interior permanent magnet synchronous motor according to the ninth aspect, after the convergence is determined by the convergence determination process, the torque error as the first information remains. It is determined whether or not the torque command value has remained, and if the torque command value remains, a new torque command value is obtained by subtracting the remaining torque error from the torque command value set at one operating point, and the new torque command value is obtained. The value is set and changed to the torque command value at the operating point.

  If a torque error remains after the convergence of the data in the search mode, it is an operation limit of the torque output at the rotation speed at that time, and the torque output cannot follow the preset torque command value. , The d-axis current command value data cannot be obtained.

  However, according to the configuration of the ninth aspect, the torque value at the operating limit at a certain rotational speed is automatically additionally set as an operating point (setting is changed to a new torque command value), and the d-axis current at which the maximum torque is obtained is obtained. Command value and q-axis current command value data can be obtained.

In the current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 10, the second information is input power of an inverter according to any one of claims 7 to 9,
In the second search mode in the d-axis current command value generation process, when the d-axis current command value is changed, the input power before and after the change is observed, and the specified d-axis current value at which the input power is minimized Exploring,
The first search mode in the d-axis current command value generation processing is to observe a torque error as the first information before and after the change when the d-axis current command value is changed in the negative direction, Is characterized by searching for a d-axis current command value in which is zero or minimum.

According to a twentieth aspect of the present invention, in the method for automatically generating a current command table of an interior permanent magnet synchronous motor according to the twelfth aspect, the second information is an input power of an inverter.
In the second search mode in the d-axis current command value generation step, when the d-axis current command value is changed, the input power before and after the change is observed, and the d-axis current specified value at which the input power is minimized Exploring,
In the first search mode in the d-axis current command value generation step, when the d-axis current command value is changed in the negative direction, a torque error as the first information before and after the change is observed, and the torque error is calculated. Is characterized by searching for a d-axis current command value in which is zero or minimum.

  According to the above configuration, in the first search mode in which the current / voltage limit value of the inverter is exceeded, the d-axis current command value at which the maximum output can be obtained with the current / voltage limited by the maximum output control method, q In the second search mode in which the shaft current command value is determined and is equal to or less than the current / voltage limit value of the inverter, the d-axis current command value at which the maximum torque is obtained with the minimum power consumption (input power of the inverter) by the maximum efficiency control method , Q-axis current command value.

An automatic current command table generation system for an interior permanent magnet synchronous motor according to claim 11 is the current amplitude limit processing unit provided in the current command table automatic adjustment device according to any one of claims 7 to 9. With
The current amplitude limiting processing unit calculates a current amplitude value from a d-axis current command value before the current amplitude limiting process and a q-axis current command value,
The second information is the calculated current amplitude value,
In the second search mode in the d-axis current command value generation process, when the d-axis current command value before the current amplitude limiting process is changed, the current amplitude value before and after the change is observed. Search for the minimum d-axis current command value,
The first search mode in the d-axis current command value generation processing is to observe a torque error as the first information before and after the change when the d-axis current command value is changed in the negative direction, Is characterized by searching for a d-axis current command value in which is zero or minimum.

According to a twenty-first aspect of the present invention, in the method for automatically generating a current command table for an interior permanent magnet synchronous motor according to the nineteenth aspect, the current amplitude limit processing unit provided in the current command table automatic adjustment device includes a current amplitude limit processing unit. A step of calculating a current amplitude value from the previous d-axis current command value and the q-axis current command value,
The second information is the calculated current amplitude value,
In the second search mode in the d-axis current command value generation step, when the d-axis current command value before the current amplitude limiting process is changed, the current amplitude value before and after the change is observed. Search for the minimum d-axis current command value,
In the first search mode in the d-axis current command value generation step, when the d-axis current command value is changed in the negative direction, a torque error as the first information before and after the change is observed, and the torque error is calculated. Is characterized by searching for a d-axis current command value in which is zero or minimum.

  According to the above configuration, in the first search mode in which the current / voltage limit value of the inverter is exceeded, the d-axis current command value at which the maximum output can be obtained with the current / voltage limited by the maximum output control method, q In the second search mode in which the shaft current command value is determined and is equal to or less than the current / voltage limit value of the inverter, the d-axis current command value and the q-axis current at which the maximum torque can be obtained with the minimum current amplitude by the maximum torque / current control method The command value can be determined.

A current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 12 is the current amplitude limiting process provided in the current command table automatic adjustment device according to any one of claims 7 to 9. Unit and the voltage amplitude limit processing unit provided in the inverter control unit,
The voltage amplitude limiting processing unit calculates a voltage command duty ratio from a d-axis voltage command value, a q-axis voltage command value, and a DC input voltage of the inverter before the voltage amplitude limiting process,
The second information is the calculated voltage command duty ratio,
The second search mode in the d-axis current command value generation process is to observe the voltage command duty ratio before and after the change when changing the d-axis current command value before the current amplitude limiting process, Search for the d-axis current command value that minimizes the ratio,
The first search mode in the d-axis current command value generation processing is to observe a torque error as the first information before and after the change when the d-axis current command value is changed in the negative direction, Is characterized by searching for a d-axis current command value in which is zero or minimum.

A method for automatically generating a current command table for an interior permanent magnet synchronous motor according to claim 22 is provided in the current amplitude limit processing section and the inverter control section provided in the current command table automatic adjusting device. The voltage amplitude limit processing unit,
The voltage amplitude limit processing unit includes a step of calculating a voltage command duty ratio from a d-axis voltage command value, a q-axis voltage command value, and a DC input voltage of the inverter before the voltage amplitude limit process,
The second information is the calculated voltage command duty ratio,
In the second search mode in the d-axis current command value generation step, when the d-axis current command value before the current amplitude limiting process is changed, the voltage command duty ratio before and after the change is observed, and Search for the d-axis current command value that minimizes the ratio,
In the first search mode in the d-axis current command value generation step, when the d-axis current command value is changed in the negative direction, a torque error as the first information before and after the change is observed, and the torque error is calculated. Is characterized by searching for a d-axis current command value in which is zero or minimum.

  According to the above configuration, in the first search mode in which the current / voltage limit value of the inverter is exceeded, the d-axis current command value at which the maximum output can be obtained with the current / voltage limited by the maximum output control method, q In the second search mode in which the shaft current command value is determined and the current is less than or equal to the current / voltage limit value of the inverter, the maximum torque is obtained with the minimum magnetic flux (induced voltage) by the maximum torque / magnetic flux control (induced voltage control) method. An axis current command value and a q-axis current command value can be determined.

  According to a thirteenth aspect of the present invention, there is provided an automatic current command table generating system for an interior permanent magnet synchronous motor according to any one of the first to twelfth aspects, wherein the automatic current command table adjusting device performs q-axis control for maximum efficiency control. A current is obtained in advance by analysis, and the obtained q-axis current is used as an initial value of a q-axis current command value when performing the torque feedback control.

  According to the above configuration, the convergence of the torque feedback control can be accelerated.

  An automatic current command table generation system for an interior permanent magnet synchronous motor according to a fourteenth aspect of the present invention is the d-axis automatic current command table automatic adjustment device according to any one of the first to thirteenth aspects, wherein the d-axis is a maximum efficiency control. The current is obtained in advance by analysis, and the obtained d-axis current is used as an initial value of the d-axis current command value in the d-axis current command value generation processing.

  According to the above configuration, the number of data searches during the d-axis current command value generation processing is reduced, and the convergence of the d-axis current command value data is accelerated.

An automatic current command table generation system for an interior permanent magnet synchronous motor according to a fifteenth aspect of the present invention is the automatic current command table adjusting device according to any one of the tenth to fourteenth aspects, wherein Part,
The d-axis current command value limiter limits the d-axis current command value when the magnitude of the d-axis current command value to be changed in the negative direction becomes larger than the set limit value. Processing is performed.

  According to the above configuration, since the magnitude of the d-axis current in the negative direction is limited, it is possible to prevent the permanent magnet of the embedded magnet synchronous motor from causing irreversible demagnetization.

  In the automatic current command table generating system for an interior permanent magnet synchronous motor according to claim 16, the automatic current command table adjusting device according to any one of claims 7 to 15, wherein the automatic current command table adjusting device is generated for all the operating points. The d-axis current command value and the data of the q-axis current command value are divided into data that is equal to or less than a limit value and data that exceeds the limit value in at least one of the current amplitude limiting processing unit and the voltage amplitude limiting processing unit, It is characterized in that a data interpolation process is performed for each of the divided data to make a table.

  In the operating point region where the state is switched from the state below the limit value to the state exceeding the limit value, the characteristics of the current command table greatly change. In this regard, according to the configuration of claim 16, since the interpolation processing is performed for each of the data divided into the data exceeding the limit value and the data below, the accuracy in the boundary region of the table data is reduced. Can be improved.

(1) According to the present invention, a torque command is given to an inverter that performs variable speed control of an embedded magnet synchronous motor, and torque control is performed. It is possible to automatically generate a current command table that enables conversion into a value and a q-axis current command value with high accuracy and high efficiency.
(2) According to the second aspect of the invention, the d-axis current command value and the q-axis current command value that can obtain the maximum torque with the minimum current amplitude can be determined by the maximum torque / current control method. For this reason, the d-axis current command value and the q-axis current command value that minimize the copper loss of the interior permanent magnet synchronous motor can be generated.

Also, during the d-axis current command value and q-axis current command value generation processing, the detected (actually measured) motor current amplitude value is observed instead of the calculated motor current amplitude value. A higher-precision current command table can be automatically generated without receiving the current command table.
(3) According to the third aspect of the invention, there is no need to detect the motor current and take in the detection signal, so that the number of signals between the motor current table automatic adjustment device and the calculation inside the inverter is simplified. Be transformed into
(4) According to the fourth aspect of the present invention, the d-axis current command value and the q-axis current command value that provide the maximum torque with the minimum power consumption (input power of the inverter) are determined by the maximum efficiency control method. be able to. Therefore, it is possible to generate the d-axis current command value and the q-axis current command value that minimize the total loss such as the iron loss and the copper loss of the interior permanent magnet synchronous motor.
(5) According to the fifth aspect of the present invention, the d-axis current command value and the q-axis current command value that provide the maximum torque with the minimum magnetic flux (induced voltage) by the maximum torque magnetic flux control (induced voltage control) method. Can be determined. Therefore, it is possible to generate a d-axis current command value and a q-axis current command value that minimize the iron loss of the interior permanent magnet synchronous motor.
(6) According to the sixth and eighteenth aspects of the invention, it is possible to generate the current command table after previously compensating for the torque reduced by no-load loss such as mechanical loss.
(7) According to the seventh and 19th aspects of the invention, there is provided a current command table generation method of a control method suitable for each operation area of maximum efficiency control and maximum output control depending on whether or not the current and voltage of the inverter are limited. It can be switched appropriately.
(8) According to the invention as set forth in claim 8, even when the first or second search mode repeatedly makes a state transition, the data at the time of executing the mode can be converged.
(9) According to the ninth aspect of the invention, a torque value at an operation limit at a certain rotational speed is automatically additionally set as an operating point (setting is changed to a new torque command value), and d becomes a maximum torque. Data of the axis current command value and the q-axis current command value can be obtained.
(10) According to the tenth and twentieth aspects, in the first search mode in which the current / voltage limit value of the inverter is exceeded, the maximum output is controlled in a state where the current / voltage is limited by the maximum output control method. Are determined, and in the second search mode below the inverter current / voltage limit value, the maximum efficiency control method is used to minimize power consumption (input power of the inverter). It is possible to determine the d-axis current command value and the q-axis current command value at which the maximum torque is obtained.
(11) According to the eleventh and twenty-first aspects, in the first search mode in which the current / voltage limit value of the inverter is exceeded, the maximum output is controlled with the current / voltage limited by the maximum output control method. The d-axis current command value and the q-axis current command value are obtained. In the second search mode in which the current and the voltage are not more than the current / voltage limit values of the inverter, the maximum torque is obtained with the minimum current amplitude by the maximum torque / current control method. The specified d-axis current value and the specified q-axis current value can be determined.
(12) According to the invention as set forth in claims 12 and 22, in the first search mode in which the current / voltage limit value of the inverter is exceeded, the maximum output is controlled in a state where the current / voltage is limited by the maximum output control method. Are determined, and in the second search mode below the inverter current / voltage limit value, the minimum flux (maximum torque / flux control (induced voltage control) method) is determined in the second search mode. It is possible to determine the d-axis current command value and the q-axis current command value at which the maximum torque is obtained by the induced voltage).
(13) According to the thirteenth aspect, the convergence of the torque feedback control can be accelerated.
(14) According to the fourteenth aspect, the number of data searches during the d-axis current command value generation processing is reduced, and the convergence of the d-axis current command value data is accelerated.
(15) According to the invention of claim 15, since the magnitude of the d-axis current in the negative direction is limited, it is possible to prevent the permanent magnet of the embedded magnet synchronous motor from causing irreversible demagnetization.
(16) According to the invention described in claim 16, since the interpolation processing is performed for each data divided into the data exceeding the limit value and the data below, the accuracy in the boundary region of the table data is reduced. Can be improved.

FIG. 1 is a basic configuration diagram of a current command table automatic generation system according to an embodiment of the present invention. FIG. 1 is a configuration diagram of a current command table automatic generation system according to a first embodiment of the present invention. FIG. 1 is an internal configuration diagram of a current command table automatic adjustment device according to a first embodiment of the present invention. 9 is a basic flowchart of a current command table automatic generation process according to the embodiment of the present invention. FIG. 4 is a configuration diagram showing a use form of a current command table in the embodiment of the present invention. FIG. 9 is a configuration diagram of a current command table automatic generation system according to a second embodiment of the present invention. FIG. 9 is a configuration diagram of a current command table automatic generation system according to a third embodiment of the present invention. FIG. 10 is an internal configuration diagram of a current command table automatic adjustment device according to a third embodiment of the present invention. FIG. 13 is a configuration diagram of a current command table automatic generation system according to a fourth embodiment of the present invention. FIG. 13 is an internal configuration diagram of a current command table automatic adjustment device according to a fourth embodiment of the present invention. FIG. 13 is an internal configuration diagram of a current command table automatic adjustment device according to a fifth embodiment of the present invention. FIG. 13 is a configuration diagram showing a use form of a current command table to which the fifth embodiment of the present invention is applied. FIG. 4 is a torque-rotation speed characteristic diagram showing a range of maximum efficiency control and maximum output control executed in the present invention. FIG. 13 is a configuration diagram illustrating a main part of an automatic current command table generation system according to a sixth embodiment of the present invention. 16 is a flowchart of a current command table automatic generation process according to the sixth embodiment of the present invention. FIG. 13 is an internal configuration diagram of a current command table automatic adjustment device according to a tenth embodiment of the present invention. 21 is a flowchart of a current command table automatic generation process according to the tenth embodiment of the present invention. FIG. 19 is an internal configuration diagram of a current command table automatic adjustment device according to an eleventh embodiment of the present invention. 21 is a flowchart of a current command table automatic generation process according to the eleventh embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In the present embodiment, a current command table automatically generates a d-axis and q-axis current command value (amplitude / phase information of a current command value) of an interior permanent magnet synchronous motor with high accuracy and automatically based on an actually measured value. The present invention provides a system and a method, and its basic configuration is shown in FIG.

  In FIG. 1, a target interior permanent magnet synchronous motor 10 is axially connected to an arbitrary load servo device 20. A torque meter 11 is provided on a joint shaft between the motor 10 and the load servo device 20 so that shaft torque can be detected. For the load servo device 20, a general servo motor control device or the like is used, and speed control is performed so as to achieve a designated rotation speed.

Reference numeral 30 denotes various information of the current command table automatic generation system, that is, a torque detection value τ of the torque meter 11, a speed detection value ω _m output from the load servo device 20, a motor current current value Im, and a voltage, which will be described later. A current for generating a d-axis current command value _id ^* and a q-axis current command value _iq ^* based on the command duty ratio Dv, the input power (power consumption) Pi of the inverter 40 for driving the motor 10, and the like, and tabulating the current. It is a command table automatic adjustment device.

  In the inverter 40, general current vector control is performed using rotation coordinate conversion synchronized with the rotation phase θ detected by the rotation position sensor 12 attached to the motor 10.

The inverter control unit (41) of the inverter 40 defines the d axis in the direction of the N pole of the permanent magnet in the rotating coordinate system, and sets the q axis to a phase advanced by 90 degrees from the d axis. Then, the three-phase current detection values i _u , i _v , and i _w of the motor 10 detected by the current sensor 13 are subjected to the rotation coordinate conversion of the equation (1) to detect the d-axis current detection value _id and the q-axis current detection. Convert to value _iq .

And the current command table d-axis current command value sent from the automatic adjustment device 30 i _d ^* and the q-axis current command value i _q ^*, the detected value i _d, i _q is the PID control or the like so as to follow each Performs automatic control (current feedback control). The output of this automatic controller becomes a d-axis voltage command value v _d ^* and a q-axis voltage command value v _q ^* , and a gate signal is created by PWM control or the like, and the semiconductor switching element of the inverter is controlled. 14 is a DC power supply for the inverter 40, and 15 is a power meter.

In the current command table automatic adjusting device 30, the current command value i _d ^* based torque command value (tau ^*) of the speed detection value omega _m, determine the value of i _q ^*. As will be described later in each example of this determination method, the torque detection value tau, the speed detection value omega _m, the current amplitude value Im, i using the voltage command duty ratio Dv, the input power (power consumption) Pi like _d ^* , I _q ^* automatically adjust the current command table (amplitude and phase of the motor current).

  Here, the current amplitude value Im is expressed by equation (2), and the voltage command duty ratio Dv is expressed by equation (3).

V _DC : DC voltage value of DC power supply (inverter DC input) Note that the current amplitude value Im may be calculated inside the inverter 40, or the three-phase current may be directly taken into the current command table automatic adjustment device 30 to obtain the amplitude. May be calculated.

  The input power (power consumption) Pi is detected using a wattmeter 15 or the like in the DC power supply 14 part. Although the total power consumption of the inverter / motor is measured in FIG. 1, the power consumption of the motor alone can be obtained by measuring at the inverter output unit.

  Hereinafter, each embodiment will be described.

In the present embodiment, the maximum torque / current control is employed for determining the d-axis and q-axis current command values (current amplitude / phase). Maximum torque / current control is a scheme of current amplitude is adjusted i _d, i _q to smallest phase when outputting torque. Driving an interior permanent magnet synchronous motor with the current phase determined in this manner minimizes copper losses in the motor.

Equation (4) shows a general torque equation. (4) to 0 by partial differentiation by the current phase angle β of the equation, when guiding the optimal current phase current amplitude is minimum as relation of i _d, i _q (5) is obtained. Here, p: the number of pole pairs, Δ: armature interlinkage magnetic flux by a permanent magnet, L _d : d-axis inductance, and L _q : q-axis inductance.

The theoretically possible to realize the maximum torque / current control be decided i _d and i _q based on the equation (5), in the actual motor drive system, an inverter, cable, sensor characteristics, current and frequency-dependent Due to certain resistance / inductance fluctuations, temperature dependence of a magnetic circuit such as a permanent magnet, and the like, errors from design values and analysis values occur. Therefore, the output torque with higher accuracy and high efficiency, it is necessary to adjust the i _d, i _q based on the measured value.

  Therefore, in this embodiment, as shown in FIG. 2, the torque τ and the current amplitude value Im are detected, and the current command table is automatically adjusted. 2, the same parts as those in FIG. 1 are indicated by the same reference numerals.

  The current command table automatic adjustment device 30 performs the current command table automatic generation process shown in FIG. 4 with the configuration shown in FIG. 3 and performs a two-dimensional current command table according to the operating point (the operating state of the torque and the number of revolutions). Is automatically generated.

In FIG. 3, reference numeral 31 denotes a function for determining a speed command value and a torque command value at one operating point, which will be described later, and the speed detection value ω _m and the torque detection value τ are the speed command value ω _m ^* and the torque command value τ ^* . This is a torque & speed command value setting processing unit having a function of checking whether they match, and a function of changing the operating point.

32 is a subtractor for subtracting the torque detection value τ detected by the torque meter 11 from the torque command value τ ^* , and 33 performs tracking control by PID control, and the torque detection value τ matches the torque command value τ ^* . This is a torque controller (adjuster) that controls so as to perform (performs torque feedback control). Reference numeral 34 denotes a d-axis current adjuster that searches for a d-axis current command value _id ^* at which the detected current amplitude Im is minimized.

  Next, the current command table automatic generation processing in FIGS. 2 and 3 will be described with reference to FIG.

In <Step S1 (data acquisition preparation)>, the torque & speed command value setting processing unit 31 executes the current command of the d-axis current command value _id ^* and the q-axis current command value _iq ^* in two dimensions of the rotation speed and the torque. In order to generate a table, the range and number of rotations and the range and number of torques are arbitrarily set in accordance with the specifications of the motor such as a constant torque range and a constant output range (command value setting step).

  For example, if it is desired to generate a table with a motor rotation speed range of -1000 rpm to 1000 rpm in increments of 100 rpm and a torque range of -100 Nm to 100 Nm in increments of 10 Nm, the number of rotations is 21 points x torque 21 points = 441 points in total. Set the operating point. In addition, in consideration of the temperature dependence of various parameters of the motor, a sufficient warm-up operation is performed, and then the current command table automatic generation processing is started.

<Step S2 (current command table automatic generation processing loop start)> is the full operating point set in advance in step S1, a loop to repeat the process of determining the sequence i _d, i _q. After obtaining the data of i _d, i _q in one operating point, performs processing to shift to the next operating point. This is repeated until data of all operating points is obtained.

In step S3 (rotation speed command setting / speed control), the rotation speed setting value (speed command) ω _m ^* set in step S1 is transmitted to the load servo device 20 in FIG. 2, and the rotation speed is set to a desired value. (Speed control step). Speed control is performed in the load servo device 20, and a rotation speed detection value (speed detection value) ω _m is returned to the current command table automatic adjustment device 30. In the torque & speed command value setting processing section 31 of FIG. 3, it is confirmed that the detected rotation speed matches the desired set value, and the process proceeds to step S4.

In <Step S4 (torque command setting / torque control)>, the subtractor 32 and the torque controller 33 shown in FIG. 3 perform torque feedback so that the torque command value τ ^* set in Step S1 matches the torque detection value τ. Perform control. The deviation between the torque command and the detection is tracked using a general PI control, and the PI control output (output of the torque controller 33) is set as a q-axis current command value _iq ^* (q-axis current command value generation step). . At this time, the initial value of the d-axis current command value _id ^* is set to 0 ( _id ^* = 0 control). The processing for the d-axis current regulator is performed in step S5 in the subsequent stage. After confirming that the detected torque value matches the set value, the process proceeds to step S5.

In <Step S5 (d-axis current adjustment)>, the d-axis current adjuster 34 searches for _id ^* that minimizes the current amplitude detection value Im (d-axis current command value generation step). The search method is not particularly limited, but a general hill-climbing method, a steepest descent method, or the like may be used. For example, the d-axis current command value _id ^* is changed in the negative direction at an arbitrary step width from the initial value of _id ^* = 0. The current amplitude value Im before and after the change is observed, and if the current amplitude value becomes smaller than before the change, _id ^* is further changed in the negative direction. By repeating this process, it is possible to search for _id ^* that minimizes the current amplitude. At this time, if the d-axis current command value _id ^* is changed, the torque τ also changes. However, since the processing of the previous step S4 (torque feedback control in FIG. 3) is effective, the change in _id ^* Accordingly, _iq ^* is automatically adjusted so that torque τ always matches torque command value τ ^* . Therefore, _id ^* and _iq ^* can automatically realize maximum torque / current control (current phase that outputs maximum torque with minimum current amplitude). It is confirmed that _id ^* and _iq ^* have converged by this process, and the process proceeds to step S6.

<(I _d ^* for setting the operating point, i _q ^* current command data recording) Step S6> In, i _d ^* obtained in step S4, S5, and i _q ^*, respectively the rotation speed-torque setting value at that time Record in memory.

In <Step S7 (current command table automatic generation processing loop end)>, i _d ^* in all operating points, if i _q ^* data has been acquired proceeds to the subsequent step S8, otherwise preceding The process returns to step S2 to set and shift to another unrecorded operating point, and repeat the loop of steps S3 to S6.

<Step S8 (full operating point i _d ^*, i _q ^* current command data read)> In reads the i _d ^*, i _q ^* of data over the operating point acquired from the memory, the process proceeds to step S9.

In <Step S9 (current command table generation)>, all operating points of the i _d ^* read in step S8, by using the i _q ^* data, deploying the rotational speed and the torque as a two-dimensional table as input. When making the table, normalization and various data interpolation (eg, cubic spline interpolation) may be performed. Table is 2 input (speed and torque) 1 Output (i _d ^* or i _q ^*) that the format of the data, in the example of the operation point of 441 points described in step S1, for the 441-point table i _d ^* And two types for _iq ^* are generated and the process ends.

Above the current command table that is automatically generated as, implemented as a program in the inverter inside the microcomputer, in accordance with the operation state of the motor (rotation number of states and a torque command) conforming i _d ^*, i _q The data of ^* is read out by linear interpolation or the like, and used as a d-axis current command value and a q-axis current command value. Therefore, after the current command table is automatically generated, the target embedded magnet synchronous motor may be driven by an arbitrary inverter without requiring a device configuration such as torque feedback as shown in FIGS. 2 and 3 are used only when a high-precision current command table based on actual measurement is automatically generated. FIG. 5 shows an example of a usage form in a case where the current command table automatically generated by the configuration of FIGS. 2 and 3 is mounted on a general vector control inverter.

  The use form of the current command table of FIG. 5 will be described below. 5, the same parts as those in FIG. 2 are denoted by the same reference numerals, 200 denotes a load, and 400 denotes an arbitrary inverter.

52 in the inverter control unit 51 converts the three-phase current detection values i _u , i _v , and i _w of the embedded magnet synchronous motor 10 detected by the current sensor 13 into d by performing the rotation coordinate conversion of the equation (1). is a coordinate converter for converting the axial current detection value i _d and the q-axis current detection value i _q.

Reference numeral 53 denotes a speed calculation unit that calculates the rotation speed ω _m (speed detection value) from the rotation phase θ of the motor 10 detected by the rotation position sensor 12.

2, the current command table 300, which is automatically generated in the flow chart of FIG configuration and 3 4 is mounted on the inverter control unit 51 in the form of a two-dimensional table with the torque command tau ^* the rotational speed omega _m and arguments . The d-axis current command value _id ^* and the q-axis current command value _iq ^* are output from the table, and the current follow-up control ( _id ^* , _iq ^* and id ₎ on the rotational coordinates is performed by the vector control unit 55 at the subsequent stage. , _Iq coincide with each other. The resulting d-axis voltage command value v _d ^* and q-axis voltage command value v _q ^* are inversely converted into three-phase voltage command values v _u ^* , v _v ^* , v _w ^* by the coordinate conversion unit 58. Thereafter, the PWM control section 59 generates a gate signal by PWM control such as triangular wave carrier comparison, and controls the inverter 400.

  The present embodiment contributes to the reduction of the torque error (higher accuracy) and the higher efficiency (minimum current) of the current command table in FIG. The feature of the method is that it is possible to search for an optimal d-axis current with high efficiency while maintaining a state in which the q-axis current is automatically controlled while performing torque feedback control.

According to this embodiment, in a device configuration capable of torque feedback control and current amplitude detection, the current command value for realizing the maximum torque / current control current amplitude is minimum (motor copper loss is minimized) with high accuracy i _d ^{* And} _iq ^* can be automatically determined and tabulated. Therefore, there is a great effect high accuracy and minimize the copper loss of the torque output, and i _d ^*, a labor saving by automatic generation of i _q ^* automatic adjustment and tables.

In the first embodiment, when minimizing the current amplitude, the current amplitude detection value (Im) of Expression (2) is returned from the inverter 40. In this embodiment, a current command value is used for calculating a current amplitude in order to simplify calculation and reduce input / output signals. If the current feedback control in the inverter control unit of the inverter 40 functions correctly, the current detection value and the current command value match. Therefore, as shown in equation (6), the current amplitude value Im is calculated using the d-axis and q-axis current command values _id ^* and _iq ^* .

  Compared to the configuration of FIG. 2 using the current amplitude detection value, in the present embodiment, as shown in FIG. 6, feedback of the current amplitude detection value is not required, and the number of signals between the current command table automatic adjustment device 30 and the inverter internal Is simplified. The calculation of the expression (6) may be executed inside the current command table automatic adjustment device 30.

  6, the same parts as those in FIG. 2 are denoted by the same reference numerals. The current command table automatic generation processing is performed in the same manner as in the first embodiment, and a description thereof will be omitted.

  In the first and second embodiments, the d-axis current was adjusted so as to minimize the current amplitude in order to minimize the copper loss. However, from the viewpoint of efficiency, the d-axis current was adjusted in consideration of the iron loss of the motor. It is desirable to do. Also, in order to maximize the overall system efficiency of the inverter / motor, it is desirable to minimize the inverter input power.

  Therefore, in this embodiment, a method of measuring the input power and adjusting the d-axis current is used. The current command table automatic generation system uses the configuration shown in FIG. FIG. 8 shows the internal configuration of the current command table automatic adjustment device 30. 7 and 8, the same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals. The difference from FIGS. 2 and 3 is that the input power Pi of the inverter is input to the d-axis current adjuster 34 of the automatic current command table adjusting device 30.

  The input power Pi of the inverter may be obtained by detecting the power of the DC power supply output with an arbitrary measuring instrument (for example, the power meter 15). In the case of an inverter with a rectifier that obtains a DC power supply from an AC input power supply through a rectifier, the power of the AC input power supply may be measured. The inverter input power is input to the current command table automatic adjustment device 30 as a power consumption detection value Pi.

The flow chart of the current command table automatic generation is basically the same as the procedure shown in FIG. 4, and only the processing content of <Step S5 (d-axis current adjustment)> is different from that of the first embodiment. In the present embodiment in step S5 in FIG. 4, the power consumption detected value Pi to explore the i _d ^* that minimizes. The search method is not particularly limited, but a general hill-climbing method, a steepest descent method, or the like may be used.

For example, the d-axis current command value _id ^* is changed in the negative direction at an arbitrary step width from the initial value of _id ^* = 0. The detected power consumption value Pi before and after the change is observed, and if the power consumption becomes smaller than before the change, _id ^* is further changed in the negative direction. By repeating this process, it is possible to search for _id ^* that minimizes power consumption.

In this case it would be varying the d-axis current command value i _d ^* also varies torque tau, since the processing of In step S4 (torque feedback control of the torque controller 33 of FIG. 8) is activated., I _d ^* the torque tau in response to the change to always match the torque command value τ ^*, i _q ^* is adjusted automatically.

Therefore, _id ^* and _iq ^* can automatically realize maximum efficiency control (current phase that outputs maximum torque with minimum power consumption). It is only necessary to confirm that _id ^* and _iq ^* have converged by this processing, and then go to step S6 in FIG. Other processes are the same as those in the first embodiment.

  According to this embodiment, a d-axis / q-axis current command table that maximizes the overall efficiency of the inverter / motor can be automatically generated.

  In the first to third embodiments, the current command tables for the case where the current amplitude is minimized and the case where the overall efficiency is maximized are generated. The present embodiment provides a method for automatically generating a current command table for realizing maximum torque / magnetic flux control (≒ maximum torque / induced voltage control) in which linkage flux is minimized (≒ induced voltage is minimized) at the same torque. .

  In the permanent magnet synchronous motor, the induced voltage increases with the rotation speed to obtain the field magnetic flux from the permanent magnet, but the voltage range that can be controlled by the inverter is limited to a DC voltage or less. Therefore, when the motor terminal voltage rises due to the rise in the induced voltage, voltage saturation occurs, and the control cannot be performed with a desired sinusoidal waveform. As a countermeasure against the voltage saturation, flux weakening control utilizing a demagnetizing effect due to a d-axis armature reaction is generally used. As described above, it is necessary to generate a current command table for realizing the maximum torque / magnetic flux control in the high-speed rotation region.

  Therefore, in the present embodiment, the d-axis current is adjusted using the voltage command duty ratio Dv shown in Expression (3). The current command table automatic generation system uses the configuration shown in FIG. 9, and the current command table automatic adjustment device uses the configuration shown in FIG.

In the maximum torque / magnetic flux control (maximum torque / induced voltage control), a d-axis current that obtains the maximum torque under the voltage amplitude limitation is searched. Therefore, automatically controlled so that the output a is the voltage command duty ratio Dv (coordinate converted current detection value i _d of the current controller in the inverter control unit of the inverter 40, i _q are i _d ^*, it follows the i _q ^* The information of Dv) calculated from the voltage command values v _d ^* and v _q ^* obtained by the above and the DC voltage value Vdc of the DC power supply 14 by the equation (3) is input to the current command table automatic adjusting device 30, A configuration that can check the saturation status of the command is used.

The flow chart of the current command table automatic generation is basically the same as the procedure shown in FIG. 4, and only the processing content of <Step S5 (d-axis current adjustment)> is different from that of the first embodiment. In step S5 in FIG. 4 in this embodiment, to search for the i _d ^* that the limit value Dvsat the voltage command duty ratio Dv arbitrarily set. The search method is not particularly limited, but a general hill-climbing method, a steepest descent method, or the like may be used.

For example, the d-axis current command value _id ^* is changed in the negative direction at an arbitrary step width from the initial value of _id ^* = 0. Observing the change before and after the Dv, before change error between Dvsat alters the i _d ^* in the more negative direction becomes smaller than. By repeating this process, it searches the i _d ^* that the voltage command duty ratio limit value Dvsat set arbitrarily.

In this case it will also change the d-axis current command value i _d Varying the ^* torque tau, since the processing of In step S4 (torque feedback control of the torque controller 33 of FIG. 10) is activated., I _d ^* the torque tau in response to the change to always match the torque command value τ ^*, i _q ^* is adjusted automatically.

Thus, _id ^* and _iq ^* can automatically achieve maximum torque / flux control. It is only necessary to confirm that _id ^* and _iq ^* have converged by this processing, and then go to step S6 in FIG. Other processes are the same as those in the first embodiment.

  According to the present embodiment, it is possible to automatically generate a d-axis / q-axis current command table that satisfies an arbitrarily set voltage limit value (voltage command duty ratio limit value Dvsat).

  In the first to fourth embodiments, since no-load loss typified by mechanical loss is not taken into account, the current command table is generated including the loss.

  In this embodiment, after the no-load loss is measured in advance, the current command table is generated in consideration of the loss. In the device configuration shown in FIG. 1, when the speed is controlled by the load servo device 20, the loss depending on the load device is compensated by the speed control. Therefore, if the shaft torque detection value τ at the rotation speed is measured without giving a current command value to the inverter 40 that drives the interior permanent magnet synchronous motor 10, a no-load loss of the interior permanent magnet synchronous motor 10 can be obtained. . After the shaft torque detection value τ is similarly measured for each arbitrary rotation speed, a no-load loss table for the rotation speed is created.

  A control configuration example for automatically generating the current command table by separating the no-load loss of the interior permanent magnet synchronous motor 10 will be described below. Here, as a representative example, the current command table automatic adjusting device 30 of FIG. 2 at the time of the maximum torque / current control of the first embodiment is configured as shown in FIG. 11, the same parts as those in FIG. 3 are indicated by the same reference numerals.

The no-load loss that has been measured in advance constitutes a no-load loss table 35 using the input as the rotation speed (speed command) and the output as the loss torque. This loss torque is added to the torque command value τ ^* by the adder 36, and the subtractor 32 and the torque controller 33 perform torque feedback control to generate the q-axis current command value _iq ^* . The other parts perform the processing of FIG. 4 in the same manner as in the first embodiment, and automatically generate a current command table after preliminarily compensating for the torque reduced by no-load loss.

  Further, this embodiment can be applied to the second to fourth embodiments, and in that case, the same operation and effect as described above can be obtained.

  Next, FIG. 12 shows an embodiment in which a current command table generated in consideration of torque reduction due to no-load loss as in the fifth embodiment is mounted. Also in this embodiment, the amount of torque reduction due to no-load loss is added to the torque command value in advance and input to the current command table 500.

12, the same parts as those in FIG. 5 are denoted by the same reference numerals. Current command table 500 is a table generated according to Example 5, are mounted on the inverter control unit 61 in the form of a two-dimensional table with the torque command tau ^* the rotational speed omega _m and arguments.

In addition, the inverter control unit 61 is provided with a no-load loss table 35 which receives the rotation speed ω _m output from the speed calculation unit 53 as an input, and the loss torque output from the no-load loss table 35 is added to the adder 54. Is added to the torque command τ ^* and input to the current command table 500.

  According to the present embodiment, it is possible to generate a current command table by separating no-load loss such as mechanical loss in advance.

  In the first to fifth embodiments, a method of automatically generating respective current command tables based on three typical control methods generally used (maximum torque / current control, maximum efficiency control, maximum torque / induced voltage control). Suggested.

  However, in practice, it is necessary to consider various constraint conditions such as voltage saturation, overcurrent, heat generation, and magnet demagnetization of an inverter or the like that drives an embedded magnet synchronous motor. Therefore, it is useful to appropriately switch to a control method suitable for the operation region instead of applying only one control method in the entire operation region.

  Here, the features of each of the control methods are as follows.

  Maximum torque / current control: A method of determining d-axis and q-axis current command values so that the maximum torque can be obtained with the minimum current amplitude. Since the current is minimized, copper loss can be minimized.

  ・ Maximum torque / magnetic flux control (induced voltage control): A method for determining the d-axis and q-axis current command values so that the maximum torque can be obtained with the minimum magnetic flux (induced voltage). Therefore, iron loss can be minimized.

  Maximum efficiency control: A method for determining the d-axis and q-axis current command values so that the maximum torque can be obtained with the minimum power consumption, and can minimize the total loss such as iron loss and copper loss.

  For example, when efficiency is emphasized, maximum efficiency control is performed within a range that satisfies the current and voltage limit values of the inverter, as shown in FIG. May be switched to the maximum output control after satisfying the limit value. Here, the maximum output control is a control method of determining a current command value so that a maximum output is obtained in a state where a current or a voltage is limited, and it is possible to minimize a loss while maintaining the limit value. desired.

  As described above, it is necessary to select a control method that satisfies the desired performance in consideration of the rotational speed, the torque, and the voltage and current limitations of the inverter.

  Therefore, in the sixth embodiment, when the current amplitude value and the voltage amplitude value are within the set limit value range, the maximum efficiency control is performed. When the limit value is applied, the limit value is satisfied and the power consumption is minimized, that is, Provided is an automatic current command table generation method for searching for a current command value that minimizes total loss and maximizes overall efficiency.

  The configuration of the current command table automatic generation system is as shown in FIG. FIG. 14 shows a basic control configuration of the current command table automatic adjustment device 30 and the inverter control unit 41 of the inverter 40 in the sixth embodiment.

14, the same parts as those in FIG. 3 are denoted by the same reference numerals. Current command table automatic adjustment device 14 30 has an input voltage command duty ratio Dv obtained from the speed detection value omega _m · torque detection value tau · input power Pi and the inverter control unit 41. The torque command value τ ^* is generated internally. The speed command value ω _m ^* is output to the load servo device 20. The internally generated d-axis current and q-axis current command value are output to the inverter control unit 41.

Torque & speed command value setting unit 31, load and speed detection value omega _m obtained from the servo device 20 monitors the torque detection value τ obtained from the torque meter 11, the steady operation point set arbitrarily (speed command value omega _m ^*, has the function to ensure that it matches the torque command value tau ^*), and a function of changing the operating point.

The subtractor 32 and the torque controller 33 are adjusters that perform control so that the torque command value τ ^* and the torque detection value τ coincide with each other, and implement tracking control by general PID control or the like. The output of the torque controller 33 is a q-axis current command value _iq0 ^* _without considering saturation.

The d-axis current adjuster 34 uses the current limit value (current limit flag Flg_Im from the current amplitude limit processing unit 37 described later) and the voltage limit value (voltage command duty ratio Dv from the voltage amplitude limit processing unit 47 described later). Detection), the torque error Δτ, and the input power Pi are used as inputs to determine an optimal d-axis current command value to be described later, and outputs a d-axis current command value _id0 ^* without considering saturation.

Current amplitude limitation process section 37, d-axis current command value (saturation Not considered) i _d0 ^* and q-axis current command value to the (saturated non consideration) i _q0 ^*, taking into account the current amplitude limit value Imsat set arbitrarily Then, a process for limiting each current command value is performed. Current amplitude calculated in (7), Im> If the Imsat is a d-axis current command value ^{_{i d * = i d0 * ×}} (Imsat / Im), q -axis current command value i _q ^* = i _q0 ^* X (Imsat / Im). At the same time, a flag Flg_Im indicating that the current amplitude is limited is given to the d-axis current regulator 34. For ^{_{Im ≦ Imsat, i d * =}} i d0 * directly outputs the i _q ^* = i _q0 ^*.

  The inverter control unit 41 performs general vector control, and the coordinate conversion unit 42 performs vector control. Therefore, as shown in the equation (1), the three-phase current is synchronized with the rotation of the motor (dq (Axis coordinates).

d-axis current controller 45, q-axis current controller 46 performs the general PID control, a subtractor current command value, each deviation is taken at 43, 44 i _d ^*, and i _q ^*, the detected current value i _d, follow control so i _q matches. The outputs of the controllers 45 and 46 are a d-axis voltage command value v _d0 ^* _without saturation and a q-axis voltage command value v _q0 ^* _without saturation.

The voltage amplitude limit processing unit 47 calculates the voltage command amplitude value (unsaturated) Vm of the equation (8) from the above v _d0 ^* , v _q0 ^* in consideration of the voltage saturation of the inverter, and sets the Vm. Limit to the voltage amplitude limit value Vmsat.

If the Vm> Vmsat the d-axis voltage command value _{^{v d * = v d0 * ×}} (Vmsat / Vm), q -axis voltage command value v _q ^* = v may be limited as _q0 ^* × (Vmsat / Vm) . For Vm ≦ Vmsat, as _{^{v d * = v d0 *,}} v q * = v and outputs the _q0 ^*.

  Further, in order to consider the saturation state of the voltage command, the voltage command duty ratio Dv of the equation (3) is calculated and fed back to the d-axis current adjuster 34 of the current command table automatic adjusting device 30.

The coordinate inverse transform unit 48 uses the d and q-axis voltage command values v _d ^* and v _q ^* output from the voltage amplitude limit processing unit 47 to calculate the three-phase voltage command values vu ^* and vv ^* according to equation (9) ^. , Vw ^* .

The PWM control unit 49 performs general PWM control such as a triangular carrier comparison method on the three-phase converted voltage command values vu ^* , vv ^* , and vw ^* , and outputs a gate signal (switching) of the semiconductor element of the inverter. Signal).

  Next, a processing flow of the automatic current command table generation system according to the sixth embodiment will be described with reference to a flowchart of FIG.

In <Step S11 (data acquisition preparation)>, the torque & speed command value setting processing unit 31 outputs the current command of the d-axis current command value _id ^* and the q-axis current command value _iq ^* in two dimensions of the rotation speed and the torque. In order to generate a table, the range and number of rotations and the range and number of torques are arbitrarily set in accordance with the specifications of the motor such as a constant torque range and a constant output range (command value setting step).

  For example, if it is desired to generate a table with a motor rotation speed range of -1000 rpm to 1000 rpm in increments of 100 rpm and a torque range of -100 Nm to 100 Nm in increments of 10 Nm, the number of rotations is 21 points x torque 21 points = 441 points in total. Set the operating point. In addition, in consideration of the temperature dependence of various parameters of the motor, a sufficient warm-up operation is performed, and then the current command table automatic generation processing is started.

  In addition, various parameters, initial values, and the like used in the processing described later, such as the current amplitude limit value Imsat and the voltage amplitude limit value Vmsat, are set in advance.

<Step S12 (current command table automatic generation processing loop start)>, at all operating points previously set in step S11, a loop to repeat the process of determining the sequence i _d, i _q. After obtaining the data of i _d, i _q in one operating point, performs processing to shift to the next operating point. This is repeated until data of all operating points is obtained.

In step S13 (rotation speed command setting / speed control), the rotation speed setting value (speed command) ω _m ^* set in step S11 is transmitted to the load servo device 20 in FIG. 1, and the rotation speed is set to a desired value. (Speed control step). Speed control is performed in the load servo device 20, and a rotation speed detection value (speed detection value) ω _m is returned to the current command table automatic adjustment device 30. In the torque & speed command value setting processing section 31 of FIG. 14, it is confirmed that the detected value of the number of revolutions matches the desired set value, and the process proceeds to step S14.

In <Step S14 (torque command setting / torque control)>, the subtractor 32 and the torque controller 33 in FIG. 14 use the torque feedback so that the torque command value τ ^* set in Step S11 matches the torque detection value τ. Perform control. The deviation between the torque command and the detection is tracked using a general PI control, and the PI control output (output of the torque controller 33) is set to a q-axis current command value (unsaturated) i _q0 ^* (q-axis current Command value generation step). At this time, the initial value of the d-axis current command value _id ^* is set to 0 ( _id ^* = 0 control). The processing for the d-axis current adjuster is performed in a subsequent step S15. After confirming that the detected torque value matches the set value, the process proceeds to step S15.

  In <Step S15 (d-axis current adjustment)>, the d-axis current regulator 34 executes Steps S151 to S156 in a state where the q-axis current command value is automatically controlled by the torque feedback control of Step S14 in the preceding stage. Then, a process of searching for an optimal d-axis current command value is performed. As shown in FIG. 14, the d-axis current regulator 34 uses the information of the input power Pi, the torque error Δτ, the current limit flag Flg_Im, and the voltage command duty ratio Dv while considering the limitation of the current / voltage amplitude value. Search for the shaft current command value. In the present embodiment, in order to achieve maximum efficiency control, a d-axis current at which the input power is minimized (that is, the efficiency is maximized) at the same torque is obtained.

  First, in <Step S151 (current / voltage limit determination)> of FIG. 15, the thresholds of the current amplitude limit value Imsat and the voltage limit value Vmsat set in Step S11 are set using the current limit flag Flg_Im and the voltage command duty ratio Dv. Determine if it is hanging. The comparison between the current amplitude limit value Imsat and the current amplitude Im is performed by the current amplitude limit processing unit 37 in FIG. 14, and it is assumed that Flg_Im = 1 when the limit is imposed and Flg_Im = 0 when the limit is not imposed.

  The voltage amplitude limit value Vmsat may be divided by the DC voltage Vdc, converted into a unit for a voltage command duty ratio limit value Dvsat, and compared with the voltage command duty ratio Dv.

  If the amplitude of the current or the voltage is limited, the process proceeds to the mode (first search mode) of “search for minimum point of torque error” in step S152. If not limited, the mode shifts to the mode of the “input power minimum point search” of step S153 (second search mode).

The mode of “search for minimum torque error point” in step S152 means that the current or voltage amplitude is limited with _id ^* = 0 as an initial value, so that the torque feedback control in step S14 cannot follow up as it is. I do. Therefore, by flowing the d-axis current command value in the negative direction, the operating point of the d-axis current command value is moved in the direction of the maximum torque / current control or the magnetic flux weakening control, and the torque and the current / voltage restrictions are relaxed. It is necessary to eliminate errors.

Therefore, the torque error Δτ when the d-axis current command value (unsaturated) i _d0 ^* is changed is monitored, and the d-axis current is changed until the torque error Δτ coincides with the torque command value τ ^* . Then, a d-axis current command value at which the torque error becomes 0 or the torque error is minimized is searched for, and the d-axis current command value is made to converge.

The search method is not particularly limited, but a general hill-climbing method, a steepest descent method, or the like may be used. For example, the d-axis current command value _id0 ^* is changed in the negative direction at an arbitrary step width from the initial value of _id ^* = 0. The torque error Δτ before and after the change is observed, and if Δτ is smaller than before the change, _id0 ^* is further changed in the negative direction. By repeating this process, it is possible to search for _id ^* that minimizes the current amplitude.

At this time, if _id0 ^* is changed, the torque τ also changes. However, since the process of step S14 (the torque feedback control by the torque controller 33 in FIG. 14) is effective, the torque τ is changed according to the change of _id0 ^*. _Iq0 ^* is automatically adjusted so that torque τ always matches torque command value τ ^* .

  The "input power minimum point search" mode in step S153 is a mode in which the d-axis current command value at which the input power is minimum (that is, maximum efficiency control) is set in a state where the torque error Δτ is 0 and the current / voltage amplitude is not limited. Perform search processing. As described above, the search method looks for a change in the input power when the d-axis current command value is changed, and searches for a minimum input power point by a general method such as a hill-climbing method.

  In <Step S154 (convergence determination)>, it is determined that the processing has converged to the minimum point after executing the processing of “search for minimum torque error point” in step S152 or “search for minimum input power point” in step S153. Normally, the input power converges to the d-axis / q-axis current command value that minimizes the input power within the current / voltage limit range. However, due to the current / voltage amplitude limit, no matter how much the d-axis current is adjusted, the torque error If remains, it is determined that the torque error Δτ has converged to a minimum point.

  Even if the torque error is 0, the current or voltage amplitude, or both, may reach the limit value. In this case, the state transition is repeatedly performed between the two modes of the mode of step S152 relating to the limitation of the current / voltage amplitude (search for the minimum point of the torque error) and the mode of step S153 which does not involve the limit value (the search of the minimum point of the input power). Become. In this case, the number of state transitions and the duration of the above two modes during the search processing are determined, and the operation is converged as an operating point where the torque error is 0 and the input power is minimum (maximum efficiency). As described above, the d-axis / q-axis current command values can be automatically obtained such that the torque error becomes minimum or the input power becomes minimum when the torque error becomes zero.

  In <Step S155 (Evaluation of torque error)>, it is determined whether or not the torque error Δτ remains even after the d-axis / q-axis current command values have converged. As described above, if the set rotation speed and the torque reach a limit point where the torque cannot be output due to the restrictions of the motor and the inverter, the torque error may not become zero even if the d-axis current is adjusted no matter how much. This means that it is impossible to set the operating point itself, so it is necessary to change the torque command value itself at that rotational speed. If a torque error remains, the torque set value is changed in step S156 (torque set value change), and the process moves to the next operating point.

  The above is the processing content of <Step S15 (d-axis current adjustment)>. Thus, the d-axis / q-axis current command values that achieve the maximum efficiency can be obtained in consideration of the current / voltage amplitude limitation at an arbitrary operating point.

<(I _d ^* for setting the operating point, i _q ^* current command data recording) Step S16> At, i _d0 ^* determined at step S14, S15, with respect to i _q0 ^* current amplitude limitation processing unit 37 of FIG. 14 output via the process the i _d ^*, records i _q ^* to memory, respectively. Also, the rotation speed and torque set at that time are also recorded in the memory.

In <Step S17 (current command table automatic generation processing loop end)>, i _d ^* in all operating points, until the data acquisition of i _q ^* is completed, repeats the loop of steps S13 to S16. After the data of all operating points has been obtained, the process proceeds to step S18.

<Step S18 (the full operating point i _d ^*, i _q ^* current command data read)> In the read i _d ^* for all operating points acquired, the i _q ^* data from the memory, the process proceeds to step S19.

In <Step S19 (current command table generation)>, the full operating point read in step S18 i _d ^*, by using the i _q ^* data, i _d ^* and the rotational speed and the torque as a two-dimensional table with the input Tabulate _iq ^* . When making the table, normalization and various data interpolation (eg, cubic spline interpolation) may be performed. Table is 2 input (speed and torque) 1 Output (i _d ^* or i _q ^*) that the format of the data, the two generated ends with a i _d ^* for the i _q ^*.

Above the current command table that is automatically generated as, implemented as a program in the inverter inside the microcomputer, in accordance with the operation state of the motor (rotation number of states and a torque command) conforming i _d ^*, i _q The data of ^* is read out by linear interpolation or the like, and used as a d-axis current command value and a q-axis current command value. Therefore, after the current command table is automatically generated, the target embedded magnet synchronous motor can be driven by an arbitrary inverter without requiring a device configuration such as torque feedback as shown in FIGS. 1 and 14 are used only when automatically generating a highly accurate current command table based on actual measurement. FIG. 5 shows a utilization form in the case where the current command table automatically generated by the configuration of FIG. 1 and FIG. 14 is mounted on a general vector control inverter.

  In the use form of the current command table in the sixth embodiment, the current command table 300 in FIG. 5 is generated by performing the processing in FIG. 15 with the device configuration in FIGS.

  This embodiment contributes to the reduction of torque error (higher accuracy) and higher efficiency in determining d-axis / q-axis current command values (current amplitude / phase of each axis) especially for the interior permanent magnet synchronous motor. Is what you do. The feature of this device and the control method is that it is possible to search for an optimal d-axis current with high efficiency while maintaining a state in which the q-axis current is automatically controlled while performing torque feedback control. It is to be able to automatically determine the command values of the d-axis current and the q-axis current that provide the highest efficiency even in the limited state in consideration of the limitation on the specification of the current amplitude and the voltage amplitude of the inverter. In addition, by automating the generation of the optimal current command table, the number of steps involved in generating the table can be reduced, which has a great effect on labor saving.

  In the sixth embodiment, the d-axis current and the q-axis current command value are determined in consideration of the limitations on the current amplitude and the voltage amplitude. In this embodiment, in addition to these restrictions, the magnitude of the d-axis current in the negative direction is also limited as a measure against demagnetization of the motor magnet.

  In general, a synchronous motor using a permanent magnet can use a demagnetizing effect due to a d-axis armature reaction by flowing a negative d-axis current. This enables weak magnetic flux control to reduce the magnetic flux in the d-axis direction, and in the case of an embedded magnet synchronous motor, leads to improvement in motor characteristics. However, since the excessive demagnetizing magnetomotive force may cause irreversible demagnetization of the permanent magnet, it is necessary to limit the magnitude of the negative d-axis current.

Therefore, in the present embodiment, the magnitude | _id ^* | of the d-axis current command value _id ^* is limited in addition to the current amplitude / voltage amplitude limitation. For example, the current amplitude limitation processing unit 37 of FIG. 14, in addition to the current amplitude limitation process of Example 6, | i _d0 ^* | is the d-axis current limit value | established a limiter that limits if it exceeds | Id_sat In the case of restriction, Flg_Im is set to 1. By adding this processing, it is possible to prohibit the d-axis current condition that may cause irreversible demagnetization of the permanent magnet.

  In the current command table automatic generation flowchart of FIG. 15, in the sixth embodiment, a torque error remains even after the search for the d-axis current converges in the process of step S155 (torque error evaluation) of step S15 (d-axis current adjustment). In this case, a process of changing the torque set value (step S156) is performed. If the torque error remains, it is the operating limit of the torque output at the rotation speed at that time, and cannot follow the preset torque command value. Therefore, the data of the torque set value at that time is not recorded in the memory, but the operation is shifted to the next operating point.

  In the present embodiment, when a torque error remains as described above, the minimum point search result of the torque error Δτ is used to subtract from the set torque command value, and the subtracted torque is used as a new torque command value. Are recorded in the subsequent step S16.

For example, if the torque error minimum point search result when the torque error remains is Δτmin, the new torque command value is τ ^* −Δτmin. In step S16, the new torque command value, the rotational speed set value at that time, the d-axis current command value _id ^* , and the q-axis current command value _iq ^* are recorded.

  According to the present embodiment, the torque value at the operation limit at an arbitrary rotational speed can be automatically additionally set as the operating point, and the data of the maximum torque can be recorded.

In the first to eighth embodiments, in the d-axis current adjustment in steps S5 and S15, the adjustment is started by setting the initial value of the d-axis current to _id ^* = 0. The d-axis current is adjusted in the negative direction with 0 as an initial value. For example, a d-axis current at which the input power is minimum (maximum efficiency) at a steady operating point was searched.

  For the search algorithm, a general method such as the hill-climbing method or the steepest descent method may be used.However, in order to reduce the number of searches and increase the convergence speed, the initial value of the d-axis current must be close to the optimum point. Is desired. The q-axis current is determined by the feedback control of the torque controller 33 in FIGS. 3, 8, 10, 11, and 14. The initial value of the torque controller output, that is, the initial value of the q-axis current command value Also, it is possible to set the initial value of each operating point from the analysis result, and in that case, the convergence of the torque feedback control becomes faster.

  Therefore, in the present embodiment, the d-axis current and the q-axis current for the maximum efficiency control are calculated in advance from the analysis results of the simulation and the like, and are set as initial values at each operating point. The method of obtaining the analysis result is arbitrary. For example, the initial values of the d-axis current and the q-axis current are obtained from the results of the electromagnetic field analysis using the finite element method or the like. In a simpler case, using the general torque equation (Equation (10)) of the interior magnet synchronous motor and the analysis equation (Eq. (11)) of the maximum torque / current control that makes it easy to obtain the analysis equation, The d-axis current and the q-axis current at each operating point may be obtained numerically, set as initial values, and the optimum point search algorithm or the torque feedback control (steps S4, S5, S14, S15) may be performed.

Here, p: the number of pole pairs, Δ: armature interlinkage magnetic flux by a permanent magnet, L _d : d-axis inductance, and L _q : q-axis inductance.

  Since the analysis result includes errors due to various factors, the search algorithm functions to correct the error in the initial value. According to the present embodiment, since the initial values of the d-axis current and the q-axis current command value are set using the analysis results, the convergence speed of the optimal point search algorithm is increased, and the adjustment time of the current command table automatic generation system is reduced. Can be shortened.

  In the sixth to ninth embodiments, the current efficiency table is automatically generated based on the maximum efficiency control while giving priority to the overall efficiency of the inverter / motor. However, when the copper loss is intentionally reduced or the current amplitude limit is eased. Can use the maximum torque / current control as in this embodiment.

  The device configuration may be the same as that shown in FIG. The control configuration is based on FIG. 14 and the part of the current command table automatic adjustment device 30 in FIG. 14 is changed as shown in FIG. 16 (the inverter control unit 41 is the same as in FIG. 14). 16 differs from the current command table automatic adjustment device 30 in FIG. 14 in that a current amplitude Im is introduced into the d-axis current regulator 34 instead of the input power Pi.

  The current amplitude Im is calculated by the current amplitude limitation processing unit 37 as in the above equation (7), and is input to the d-axis current adjuster 34. In the maximum torque / current control, in order to adjust the d-axis current so that the current amplitude becomes the minimum at the same torque, the minimum current amplitude point is searched for in the flowchart shown in FIG. FIG. 17 may perform basically the same processing as the flowchart of FIG. 15 is different from FIG. 15 only in that step S153 (input power minimum point search) is replaced with step S157 (current amplitude minimum point search). Therefore, when the current / voltage amplitude limit is not applied, the minimum current amplitude point is determined by an arbitrary search algorithm in step S157, and when the limit is applied, the mode is changed to the mode in which the torque error minimum point is searched for in step S152 as in FIG. Just switch.

Step S157 (current amplitude minimum point search) searches for the i _d ^* in the same manner as step S5 in FIG. 4 (d-axis current adjustment).

  According to the present embodiment, the d-axis current and the q-axis satisfying the maximum torque / current control (minimum current amplitude) even in the limited state in consideration of the specification limitation of the current amplitude and the voltage amplitude of the motor and the inverter. The current command value can be automatically determined.

  The present embodiment provides a current command table automatic adjustment method for realizing maximum torque / magnetic flux control (maximum torque / induced voltage control) when it is desired to minimize iron loss of a motor and give priority to relaxation of voltage limitation.

  The device configuration may be the same as that shown in FIG. The control configuration is based on FIG. 14, and the portion of the current command table automatic adjustment device 30 in FIG. 14 is changed as shown in FIG. 18 (the inverter control unit 41 is the same as that in FIG. 14). In FIG. 18, the difference from the current command table automatic adjustment device 30 of FIG. 14 is that the input of the input power Pi is deleted.

  The voltage command duty ratio Dv received from the inverter control unit 41 is calculated by Expression (3), and is input to the d-axis current regulator 34. In the maximum torque / magnetic flux control, the d-axis current is adjusted so that the voltage amplitude becomes minimum (that is, the voltage command duty ratio Dv is minimum) at the same torque. Therefore, the minimum point of the voltage command duty ratio is determined in the flowchart shown in FIG. Explore.

  FIG. 19 may perform basically the same processing as the flowchart of FIG. 15 is different from FIG. 15 only in that step S153 (input power minimum point search) is replaced with step S158 (voltage command duty ratio minimum point search). Therefore, if the current / voltage amplitude limitation is not applied, the minimum point of the voltage command duty ratio is determined by an arbitrary search algorithm in step S158, and if the limitation is applied, the torque error minimum point of step S152 is searched in the same manner as in FIG. Just switch to mode.

  According to the present embodiment, the d-axis current and the q-axis satisfying the maximum torque / magnetic flux control (minimum voltage amplitude) even in the limited state in consideration of the specification limitation of the current amplitude and the voltage amplitude of the motor and the inverter. The current command value can be automatically determined.

  In the sixth to eleventh embodiments, the current command table can be automatically generated in consideration of the current / voltage amplitude limitation regardless of whether or not the current command voltage amplitude is limited. Changes greatly. For example, as shown in FIG. 13, the table characteristics of the d-axis current and the q-axis current command value are switched between the operation region of the maximum efficiency control and the region of the maximum output control in a state where the current or the voltage amplitude is limited. In the vicinity of the boundary where the operation area switches, it is necessary to consider a large change in the value when interpolating the table data.

Therefore, in the present embodiment, in steps S6 and S16 (recording of the set operation point _id ^* and _iq ^* current command data) in the flowcharts of FIGS. 4, 15, 17, and 19, the presence or absence of the current or voltage limitation is determined. Record at the same time. As a result, the presence / absence of the current / voltage limitation is recorded at all operating points, so that the operating region is divided according to the presence / absence of limitation. Then, in steps S9 and S19 (generation of a current command table) in FIGS. 4, 15, 17, and 19, data is interpolated for each of the divided areas, thereby improving the accuracy of the boundary area of the table data. be able to.

DESCRIPTION OF SYMBOLS 10 ... Interior magnet synchronous motor 11 ... Torque meter 12 ... Rotation position sensor 13 ... Current sensor 14 ... DC power supply 15 ... Wattmeter 20 ... Load servo device 30 ... Current command table automatic adjustment device 31 ... Torque & speed command value setting processing Units 32, 43, 44 Subtractor 33 Torque controller 34 d-axis current regulator 35 No-load loss table 36, 54 Adder 37 Current amplitude limiting processing unit 40, 400 Inverter 41, 51, 61 ... Inverter control units 42,52 ... Coordinate conversion unit 45 ... d-axis current controller 46 ... q-axis current controller 47 ... Voltage amplitude limit processing unit 48,58 ... Coordinate inverse conversion unit 49,59 ... PWM control unit 53 ... speed Arithmetic unit 55: Vector control unit 200: Load 300, 500: Current command table

Claims (22)

A system for automatically generating a current command table for converting a torque command given to an inverter that controls an embedded magnet synchronous motor to a variable speed into d-axis and q-axis current command values for vector control,
A load device that is connected to the motor through a shaft and that performs servo motor control;
A torque meter installed on the coupling shaft of the load device and the motor,
The rotational speed and torque of the motor are each divided into a predetermined rotational speed range and a torque range, and each of the divided ranges is set to a speed command value and a torque command value at one operating point, respectively.
The rotational speed of the load device, the speed control to the load device so as to be a speed command value set at the one operating point,
A q-axis current command value generation process for generating a q-axis current command value by performing a torque feedback control so that the torque detection value of the torque meter matches the torque command value set at the one operating point is executed. ,
In a state where the torque feedback control at the one operating point is performed, a d-axis current command value that is generated by searching for a d-axis current command value that satisfies a desired performance based on various information of the current command table automatic generation system. Execute the generation process,
The generation processing of the d-axis current command value and the q-axis current command value is performed for all operating points,
A d-axis current command value and a q-axis current command value generated for all the operating points, a current command table automatic adjustment device that creates a table in association with a rotation speed and a torque, respectively;
An inverter control unit that controls the inverter based on the generated d-axis current command value and q-axis current command value;
A current command table automatic generation system for an interior permanent magnet synchronous motor, comprising:   The d-axis current command value generation process includes changing the d-axis current command value, observing the current amplitude value of the detected motor current before and after the change, and searching for the d-axis current command value at which the current amplitude value becomes the minimum. 2. The current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 1, wherein: The current command table automatic adjustment device calculates the current amplitude value of the motor current from the d-axis current command value,
The d-axis current command value generation process changes the d-axis current command value, observes the calculated current amplitude value before and after the change, and searches for a d-axis current command value that minimizes the current amplitude value. The automatic current command table generation system for an interior permanent magnet synchronous motor according to claim 1, wherein:   The d-axis current command value generation process is characterized by changing the d-axis current command value, observing the input power of the inverter before and after the change, and searching for the d-axis current command value that minimizes the input power. An automatic current command table generation system for an interior permanent magnet synchronous motor according to claim 1. The d-axis current and the q-axis current obtained by performing coordinate control on the three-phase detection current of the inverter and the d-axis current command value and the q-axis current command value obtained by performing the tracking control so that the d-axis current and the q-axis current command are obtained. A voltage command duty ratio is calculated from the voltage command value, the q-axis voltage command value, and the DC input voltage of the inverter,
The d-axis current command value generation process changes the d-axis current command value, observes the voltage command duty ratio before and after the change, and searches for a d-axis current command value at which the voltage command duty ratio becomes a set limit value. 2. The current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 1, wherein: A no-load loss table, which is created by measuring the no-load loss of the motor in advance and outputs a load loss torque corresponding to a speed command value set at the one operating point,
The q-axis current command value generation process is a process in which a torque detection value of the torque meter is a torque obtained by adding a torque command value set at the one operating point and a no-load loss torque output from the no-load loss table. The current command table automatic generation system for an interior permanent magnet synchronous motor according to any one of claims 1 to 5, wherein the q-axis current command value is generated by performing torque feedback control so as to match. The current command table automatic adjustment device is provided to determine whether or not the current amplitude of the motor current exceeds the current amplitude limit value. When the current amplitude exceeds the current amplitude limit value, the d-axis current command value and the q-axis current A d-axis current and a q-axis current, which are provided in the inverter control unit and perform a current amplitude limiting process for performing a current amplitude limiting process for limiting a command value and convert the three-phase detection current of the inverter into coordinates, are d-axis current commands. Value and the q-axis current command value are followed to obtain a d-axis voltage command value and a q-axis voltage command value, and the voltage amplitude of the d-axis voltage command value and the q-axis voltage command value is a voltage amplitude limit value. It is determined whether the voltage amplitude has exceeded the voltage amplitude limit value, and when the voltage amplitude exceeds the voltage amplitude limit value, at least one of a voltage amplitude limitation processing unit that performs a voltage amplitude limitation process that limits the d-axis voltage command value and the q-axis voltage command value. One or the other,
The d-axis current command value generation processing is performed in a state where at least one of the current amplitude or the voltage amplitude exceeds the limit value in a state where the torque feedback control is being performed at the one operating point. A d-axis current command value capable of executing the first search mode and performing the maximum output control based on a torque error indicating a deviation between the torque detection value and the torque command value as the information of the current amplitude or the voltage. When at least one of the amplitudes is equal to or less than the limit value, the d-axis current command value at which the maximum efficiency control can be performed by executing the second search mode based on the second information of the current command table automatic generation system. The current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 1, wherein the current command table is generated.   The current command table automatic adjustment device performs a convergence determination process of determining whether or not data during execution of the first or second search mode has converged to a minimum point, and executes the first or second search mode. 8. The interior permanent magnet synchronous motor according to claim 7, wherein when the first or second search mode repeatedly makes a state transition, a convergence determination process is performed based on the number of times and the duration of the state transition. Automatic current command table generation system.   After the convergence is determined by the convergence determination process, it is determined whether or not a torque error as the first information remains, and if the torque error remains, a torque command value set to one operating point 9. The embedding method according to claim 8, wherein a new torque command value is obtained by subtracting the remaining torque error from the torque command value, and the new torque command value is changed to a torque command value at the operating point. Automatic generation of current command table for magnet synchronous motor. The second information is the input power of the inverter;
In the second search mode in the d-axis current command value generation process, when the d-axis current command value is changed, the input power before and after the change is observed, and the specified d-axis current value at which the input power is minimized Exploring,
The first search mode in the d-axis current command value generation processing is to observe a torque error as the first information before and after the change when the d-axis current command value is changed in the negative direction, 10. The current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 7, wherein a search is made for a d-axis current command value at which is zero or minimum. A current amplitude limit processing unit provided in the current command table automatic adjustment device,
The current amplitude limiting processing unit calculates a current amplitude value from a d-axis current command value before the current amplitude limiting process and a q-axis current command value,
The second information is the calculated current amplitude value,
In the second search mode in the d-axis current command value generation process, when the d-axis current command value before the current amplitude limiting process is changed, the current amplitude value before and after the change is observed. Search for the minimum d-axis current command value,
The first search mode in the d-axis current command value generation processing is to observe a torque error as the first information before and after the change when the d-axis current command value is changed in the negative direction, 10. A current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 7, wherein a search is made for a d-axis current command value in which is zero or minimum. The current command table automatic adjustment device provided with the current amplitude limitation processing unit provided in the inverter control unit and the voltage amplitude limitation processing unit provided in the inverter control unit,
The voltage amplitude limiting processing unit calculates a voltage command duty ratio from a d-axis voltage command value, a q-axis voltage command value, and a DC input voltage of the inverter before the voltage amplitude limiting process,
The second information is the calculated voltage command duty ratio,
The second search mode in the d-axis current command value generation process is to observe the voltage command duty ratio before and after the change when changing the d-axis current command value before the current amplitude limiting process, Search for the d-axis current command value that minimizes the ratio,
The first search mode in the d-axis current command value generation processing is to observe a torque error as the first information before and after the change when the d-axis current command value is changed in the negative direction, 10. The current command table automatic generation system for an interior permanent magnet synchronous motor according to claim 7, wherein a search is made for a d-axis current command value at which is zero or minimum.   The current command table automatic adjustment device obtains a q-axis current that is the maximum efficiency control by analysis in advance, and determines the obtained q-axis current with an initial value of a q-axis current command value when performing the torque feedback control. The automatic current command table generation system for an interior permanent magnet synchronous motor according to any one of claims 1 to 12, wherein:   The current command table automatic adjustment device obtains the d-axis current that is the maximum efficiency control by analysis in advance, and calculates the obtained d-axis current as the d-axis current command value during the d-axis current command value generation processing. 14. The automatic current command table generation system for an interior permanent magnet synchronous motor according to claim 1, wherein the current command table is set to an initial value. Comprising the current amplitude limit processing unit provided in the current command table automatic adjustment device,
The d-axis current command value limiter limits the d-axis current command value when the magnitude of the d-axis current command value to be changed in the negative direction becomes larger than the set limit value. The automatic current command table generation system for an interior permanent magnet synchronous motor according to any one of claims 10 to 14, wherein the current instruction table is processed.   The current command table automatic adjustment device may store the data of the d-axis current command value and the q-axis current command value generated for the all operating points with a limit value in at least one of the current amplitude limit processing unit or the voltage amplitude limit processing unit. 16. The padding method according to claim 7, wherein the data is divided into the following data and the data exceeding the limit value, and a data interpolation process is performed for each of the divided data to form a table. Automatic generation of current command table for magnet synchronous motor. A current command having a load device which is connected to an embedded magnet synchronous motor and is controlled by a servo motor, a torque meter installed on a coupling shaft between the load device and the motor, and an inverter which controls the motor at a variable speed. A method for automatically generating a current command table for converting a torque command given to the inverter into a d-axis and q-axis current command value for vector control, comprising a table automatic generation system,
A current command table automatic adjustment device divides the rotation speed and torque of the motor into a predetermined rotation speed range and a torque range, and sets each of the divided ranges to a speed command value and a torque command value at one operating point. Command value setting step;
A current command table automatic adjusting device, a speed control step of causing the load device to perform speed control such that the rotation speed of the load device becomes a speed command value set at the one operating point,
A current command table automatic adjusting device performs a torque feedback control so as to match a torque detection value of the torque meter with a torque command value set at the one operating point, and generates a q-axis current command value. A current command value generation step;
The current command table automatic adjustment device searches for a d-axis current command value that satisfies desired performance based on various information of the current command table automatic generation system while the torque feedback control at the one operating point is being performed. D-axis current command value generating step of generating
A step for the current command table automatic adjusting device to repeatedly execute the command value setting step, the speed control step, the q-axis current command value generation step, and the d-axis current command value generation step for all operating points;
A step of the current command table automatic adjusting device tabulating the d-axis current command value and the q-axis current command value generated for the all operating points with the rotation speed and the torque, respectively,
A method for automatically generating a current command table for an interior permanent magnet synchronous motor, comprising: A step of generating a no-load loss table in which the current command table automatic adjusting device measures a no-load loss of the motor in advance and outputs a load loss torque corresponding to a speed command value set at the one operating point. Prepared,
The q-axis current command value generation step is a step in which a torque detection value of the torque meter is a torque obtained by adding a no-load loss torque output from the no-load loss table and a torque command value set at the one operating point. 18. The method for automatically generating a current command table for an embedded magnet synchronous motor according to claim 17, wherein a q-axis current command value is generated by performing torque feedback control so as to match. The current command table automatic adjustment device is provided to determine whether or not the current amplitude of the motor current exceeds the current amplitude limit value. When the current amplitude exceeds the current amplitude limit value, the d-axis current command value and the q-axis current The d-axis current and the q-axis current, which are provided in the current amplitude limiting processing unit for performing the current amplitude limiting process for limiting the command value or the inverter control unit and coordinate-convert the three-phase detection current of the inverter, are the d-axis current command values. The d-axis voltage command value and the q-axis voltage command value are obtained by performing tracking control so as to match the q-axis current command value, and the voltage amplitudes of the d-axis voltage command value and the q-axis voltage command value are the voltage amplitude limit values. A voltage amplitude limit processing unit that determines whether the voltage amplitude has exceeded the voltage amplitude limit value and performs a voltage amplitude limit process that limits the d-axis voltage command value and the q-axis voltage command value when the voltage amplitude exceeds the voltage amplitude limit value. One side,
The d-axis current command value generation step includes a step of: when at least one of the current amplitude or the voltage amplitude exceeds the limit value in a state where the torque feedback control is being performed at the one operating point, Based on a torque error indicating a deviation between a torque detection value and a torque command value as the information of the d-axis current command value that can execute the first search mode and perform the maximum output control, When at least one of the amplitudes is equal to or less than the limit value, the d-axis current command value at which the maximum efficiency control can be performed by executing the second search mode based on the second information of the current command table automatic generation system. The method for automatically generating a current command table of an interior permanent magnet synchronous motor according to claim 17, wherein the current command table is generated. The second information is the input power of the inverter;
In the second search mode in the d-axis current command value generation step, when the d-axis current command value is changed, the input power before and after the change is observed, and the d-axis current specified value at which the input power is minimized Exploring,
In the first search mode in the d-axis current command value generation step, when the d-axis current command value is changed in the negative direction, a torque error as the first information before and after the change is observed, and the torque error is calculated. 20. The method for automatically generating a current command table for an interior permanent magnet synchronous motor according to claim 19, wherein a search is made for a d-axis current command value at which is zero or minimum. The current amplitude limit processing unit provided in the current command table automatic adjustment device includes a step of calculating a current amplitude value from a d-axis current command value before the current amplitude limit process and a q-axis current command value,
The second information is the calculated current amplitude value,
In the second search mode in the d-axis current command value generation step, when the d-axis current command value before the current amplitude limiting process is changed, the current amplitude value before and after the change is observed. Search for the minimum d-axis current command value,
In the first search mode in the d-axis current command value generation step, when the d-axis current command value is changed in the negative direction, a torque error as the first information before and after the change is observed, and the torque error is calculated. 20. The method for automatically generating a current command table for an interior permanent magnet synchronous motor according to claim 19, wherein a search is made for a d-axis current command value at which is zero or minimum. The voltage amplitude limit processing unit provided in the current amplitude limit processing unit and the inverter control unit provided in the current command table automatic adjustment device,
The voltage amplitude limit processing unit includes a step of calculating a voltage command duty ratio from a d-axis voltage command value, a q-axis voltage command value, and a DC input voltage of the inverter before the voltage amplitude limit process,
The second information is the calculated voltage command duty ratio,
In the second search mode in the d-axis current command value generation step, when the d-axis current command value before the current amplitude limiting process is changed, the voltage command duty ratio before and after the change is observed, and Search for the d-axis current command value that minimizes the ratio,
In the first search mode in the d-axis current command value generation step, when the d-axis current command value is changed in the negative direction, a torque error as the first information before and after the change is observed, and the torque error is calculated. 20. The method for automatically generating a current command table for an interior permanent magnet synchronous motor according to claim 19, wherein a search is made for a d-axis current command value at which is zero or minimum.

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