JPWO2017085853A1 - Motor control device and motor control method - Google Patents

Abstract

In the motor control device, the speed response gain is adjusted manually or automatically using an evaluation formula based on the rotational speed position detection signal. In the evaluation formula based on the rotational speed position detection signal, the process of adjusting the gain is complicated, and at the same time, the software program becomes complicated and the software load increases. In addition, a hardware system requiring a rotational speed position detector was constructed. Therefore, it is possible to easily adjust the speed response gain by changing the speed response gain to a predetermined value or a predetermined ratio in the increasing or decreasing direction and repeating the cycle of restarting until the current set value is not exceeded. A motor control apparatus and method thereof are provided.

Description

  The present invention relates to a control gain adjustment method of a motor control device that drives a motor.

  As background art of this technical field, there is JP-A-2003-61377 (Patent Document 1). In this publication, in a motor control device, a detector that is connected to a motor and detects a rotational position is provided, a positioning time that is a time until the motor position reaches a target position, a motor position overshoot, A response diagnosis unit that diagnoses vibration during servo lock when the command does not change is provided, and the cycle of driving the motor again with the gain adjusted based on the diagnosis result is repeated several times to obtain the optimal control gain. There is described a control method having an auto-tuning function that automatically tunes and determines that a predetermined evaluation function is terminated when a predetermined evaluation function becomes smaller than a preset value (see claim 1).

  Moreover, there exists Unexamined-Japanese-Patent No. 2010-252494 (patent document 2). In this publication, the motor control device observes or estimates a physical quantity related to the effective load factor or the temperature of at least one of the motor control device, the motor, and the machine, and determines that there is a high possibility of overload. A control method having a configuration for performing an overload avoidance operation for changing the control responsiveness of the control system formed in the input side path of the torque control unit in the direction of decreasing the effective load factor is described (see claim 1). ).

JP 2003-61377 A JP 2010-252494 A

  Patent Document 1 describes a control method having an auto-tuning function that automatically tunes an optimum control gain based on a signal from a detector that detects a rotational position in a motor control device.

  However, the method described in Patent Document 1 requires a detector that detects the rotational position, and does not have an inexpensive configuration, and is not applicable to a general-purpose inverter used in a system that does not have a rotational position detector. Further, the process of adjusting the gain from the position deviation is complicated, the software program becomes complicated, and the software load increases.

  Patent Document 2 describes a control method for observing or estimating a physical quantity related to an effective load factor or temperature and changing the control responsiveness so as to decrease the effective load factor when it is determined that there is a high possibility of overload. Has been.

  However, the method described in Patent Document 2 requires a detector that detects the rotational position as in Patent Document 1, and is not applicable to a general-purpose inverter. Further, although it is described that the control response gain is changed in the direction of decreasing the effective load factor, the gain may be set small enough not to cause an unstable phenomenon such as hunting as long as the effective load factor is reduced. This is only a special condition such as an overload avoidance operation and cannot be applied to the gain of normal operation.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a motor control device that automatically adjusts a speed response gain by a simple method using a current detection signal supplied to a motor without requiring complicated software and a rotational position detector, and a control method therefor Is to provide.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. For example, a current detection unit that detects a motor current supplied to a motor and generates a current detection signal; and And a control unit that controls the motor using the speed control unit that controls the speed of the motor based on a speed response gain, and a speed response gain adjustment unit that adjusts the speed response gain. And a determination unit that determines whether or not the motor current is greater than or equal to a set value, wherein the control unit controls the motor based on an input speed response gain, and the motor current is the set value When the motor current exceeds the set value, the control of the motor is stopped and the speed response gain used in the control unit is changed and re-controlled until the motor current does not exceed the set value. Succoth a motor control device according to claim.

  A motor control method in a motor control device comprising: a current detection unit that detects a motor current supplied to the motor to generate a current detection signal; and a control unit that controls the motor using the current detection signal. The control unit controls the motor based on the input speed response gain, determines whether the motor current is equal to or greater than a set value, and if the motor current is equal to or greater than the set value, Motor control characterized by repeating the cycle of stopping control of the motor and changing the speed response gain used in the control unit to perform control again until the motor current does not exceed the set value. Is the method.

  A current detection unit configured to detect a current supplied to the motor and generate a current detection signal; and a control unit configured to control the motor based on the current detection signal. A speed control unit that generates a torque command based on the speed feedback signal and the speed response gain, a current control unit that generates a voltage command based on the torque command and the current detection signal, the voltage command and the speed A PWM control unit that outputs a PWM signal for driving the motor based on a feedback signal, a speed estimation unit that generates the speed feedback signal based on the voltage command and the current detection signal, and the speed response A speed response gain adjustment unit that adjusts the gain; and an overload determination unit that determines whether or not the motor current is equal to or greater than an overload current set value. When the overload determination unit determines that the motor current is equal to or greater than the overload current set value, the PWM control unit stops outputting the PWM signal, and the speed response gain adjustment unit adjusts the speed response gain. The speed control unit generates a new speed response gain, the speed control unit generates a new torque command based on the new speed response gain, and the current control unit generates a new voltage based on the new torque command. Generating a command, and the PWM control unit outputs a new PWM signal based on the new voltage command until the motor current does not exceed the overload current set value. It is a motor control device.

  ADVANTAGE OF THE INVENTION According to this invention, the motor control apparatus which automatically adjusts an optimal speed response gain by the simple method from the electric current supplied to a motor, and its control method can be provided.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

(A) is a system configuration block diagram of a motor control device, and (b) is a system configuration block diagram of a control unit to which sensorless vector control is applied. It is the figure which showed the time series change example of the speed response gain in the increase type speed response automatic adjustment in Example 1. FIG. It is the figure which showed the time series change example of the motor rotation speed in the increase type speed response automatic adjustment in Example 1. FIG. It is the figure which showed the example of a time series change of the motor current in the increase type in Example 1, and the decrease type speed response automatic adjustment in Example 2. FIG. It is the figure which showed the example of a time series change of the speed response gain in the reduction type | mold speed response automatic adjustment in Example 2. FIG. It is the figure which showed the example of a time-sequential change of the motor rotation speed in the reduction type speed response automatic adjustment in Example 2. FIG. It is the figure which showed the time series change example of the speed response gain in the increase type speed response automatic adjustment in Example 3. FIG. It is the figure which showed the example of a time-sequential change of the speed response gain in the reduction type speed response automatic adjustment in Example 4. FIG. It is the figure which showed the flowchart in the speed response automatic adjustment which transfers to increase type from decrease type in Example 5. FIG.

  FIG. 1A shows a system configuration of the motor control apparatus of the present embodiment, and FIG. 1B shows an example of a functional block diagram of a control unit in which sensorless vector control is applied to the motor control apparatus.

  Hereinafter, examples will be described with reference to the drawings.

  Power is supplied from the three-phase AC power source 1 to the motor control device 2 to drive the motor 7. A load 9 used in a machine such as a crane is connected to the motor 7. The inside of the motor control device 2 is configured by a control unit 10 including a converter unit 3, a smoothing capacitor 4, an inverter unit 5, a drive circuit 8, a microcomputer, and the like. The converter unit 3 converts an AC voltage supplied from a three-phase AC power source into a DC voltage. The DC voltage smoothed by the smoothing capacitor 4 is converted into AC power by the inverter unit 5. The drive circuit 8 drives each switching element of the inverter unit 5 according to a PWM (Pulse Width Modulation) signal that is a drive control signal calculated by the control unit 10. The software held by the control unit 10 is composed of control blocks shown in FIG.

  The control unit 10 includes a speed control unit 11, a current control unit 12, a speed estimation unit 13, a PWM control unit 14, a speed response gain adjustment unit 15, and an overload determination unit 16. In a normal operation state, the speed controller 11 calculates a torque command c based on the speed response gain and the deviation between the set speed command a and the speed feedback signal b. The speed estimation unit 13 estimates the speed based on the current feedback signal e and the voltage command d generated by the current control unit 12, and generates a speed feedback signal b. The current detector 6 detects a motor current using a Hall element or the like mounted inside the motor control device 2 and generates a current feedback signal e. The current control unit 12 performs current control based on the current feedback signal e and the torque command c, and generates a voltage command d. The PWM control unit 14 generates a PWM signal f based on the voltage command d output from the current control unit 12 and the speed feedback signal b. The PWM signal f is transmitted to the drive circuit 8 and the motor 7 is driven through the inverter unit 5.

  In the speed response automatic adjustment, the overload determination unit 16 determines whether or not the motor current is equal to or greater than a preset overload current set value. The determination signal g is sent to the PWM control unit 14 and the speed response gain adjustment unit 15. If the determination signal g is a signal determined to be greater than or equal to the overload current set value, the PWM control unit 14 stops operation by stopping the output of the PWM signal, and the speed response gain adjustment unit 15 performs gain adjustment, A new speed response gain h is sent to the speed control unit 11. The speed control unit 11 generates a new torque command based on the new speed response gain, the current control unit 12 generates a new voltage command based on the new torque command, and the PWM control unit 14 generates a new voltage command. Based on the above, a cycle of outputting a new PWM signal is repeated. If the determination signal g is a signal determined to be less than the overload current set value, the PWM control unit 14 continues the operation as it is.

  The automatic adjustment method according to the first embodiment will be described with reference to FIGS.

  FIG. 2 shows a speed response gain time-series change in the case of performing automatic adjustment while increasing the speed response gain (hereinafter referred to as incremental speed response automatic adjustment). FIG. 3 shows a time-series change in the motor rotation speed corresponding to FIG. FIG. 4 shows the time series change of the motor current corresponding to FIG. 2 and FIG. In the case of a lifting device such as a crane, if the speed response gain is smaller than the appropriate value, the motor rotation speed may not follow the inverter output frequency, and the motor current will drop (Fig. 3), and the motor current will grow excessively. (FIG. 4). In such cases, incremental automatic adjustment is performed. Incremental automatic adjustment stops the operation (control of the motor by the control unit) when the motor current exceeds the preset overload current set value, and sets the speed response gain before the next operation. Increase the specified value and restart automatically. FIG. 2 shows an example in which, for example, the initial value set in advance is increased by two and automatically restarted. In this example, the speed response gain is increased by 20% of the initial value and the cycle is repeated until the motor current converges below the overload current set value (FIG. 2).

  The overload determination unit determines whether or not the motor current is equal to or greater than the overload current set value, and the speed response gain adjustment unit performs gain adjustment and acts to send a new speed response gain to the speed control unit.

  Thus, in this embodiment, when the motor current is equal to or higher than the overload current set value, the motor control is stopped, the speed response gain used in the control unit is increased by a predetermined value, and the motor control is performed. Try again. Then, this cycle is repeated until the motor current does not exceed the overload current set value, in other words, until the motor rotation speed reaches the set speed corresponding to the speed command and stabilizes. Thereby, complicated software and a rotational position detector are not required, and the speed response gain can be automatically adjusted by a simple method.

  The automatic adjustment method of the second embodiment will be described with reference to FIGS.

  FIG. 5 shows speed response gain time-series changes when automatic adjustment (hereinafter referred to as “decreasing type speed response automatic adjustment”) is performed while decreasing the speed response gain. FIG. 6 shows the time series change of the motor rotation speed corresponding to FIG. In the case of a general load including a crane, if the speed response gain is larger than an appropriate value, the motor causes hunting or overshoot (FIG. 6), and the current becomes pulsating. In this case as well, the motor current grows excessively as in FIG. In such a case, a reduction type automatic adjustment is performed. Decrease-type automatic adjustment stops operation when the motor current exceeds a preset overload current set value. Before the next operation, the speed response gain is decreased by a predetermined value, and the operation is automatically restarted. FIG. 5 shows an example in which the initial value is reduced by 20% as an example and the operation is automatically restarted. In this example, the speed response gain is lowered by 20% of the initial value until the motor current is equal to or less than the overload current set value and the cycle is repeated (FIG. 5).

  According to this embodiment, the speed response gain can be automatically adjusted by a simple method without requiring complicated software and a rotational position detector.

  An automatic adjustment method according to the third embodiment will be described.

  FIG. 7 is a diagram illustrating a time-series change example of the speed response gain in the second incremental speed response automatic adjustment. The main difference from the first embodiment is that the speed response gain is increased by a predetermined percentage when the previous operation is shifted to the next operation. In FIG. 7, for example, a value obtained by multiplying the initial value by 1.2 is applied as a speed response gain as an example, and a value obtained by multiplying the previous set value by 1.2 is applied at the next operation. An example of changing by 2 times is shown. In this example, the speed response gain is increased by a factor of 1.2 until the motor current converges below the overload current set value and this cycle is repeated (FIG. 7).

  According to this embodiment, the speed response gain can be automatically adjusted by a simple method without requiring complicated software and a rotational position detector.

  An automatic adjustment method according to a fourth embodiment will be described.

  FIG. 8 is a diagram showing a time-series change example of the speed response gain in the second reduced type speed response automatic adjustment. The main difference from the second embodiment is that the speed response gain is decreased by a predetermined ratio when the previous operation is shifted to the next operation. For example, FIG. 8 shows an example in which the speed response gain is decreased and changed so as to be 0.8 times the previous set value every time driving is performed. In this example, the speed response gain is decreased by 0.8 times and this cycle is repeated until the motor current converges below the overload current set value (FIG. 8).

  According to this embodiment, the speed response gain can be automatically adjusted by a simple method without requiring complicated software and a rotational position detector.

  Further, in Example 3 (FIG. 7) and Example 4 (FIG. 8), if the increase or decrease magnification is increased, the number of operations is reduced. is there. Further, if the increase or decrease magnification is lowered, the number of operations increases, but there is an effect that there is a low possibility that the appropriate value will be greatly separated.

  An automatic adjustment method according to the fifth embodiment will be described.

  If we infer the behavior of the motor and the usage of the load, it can be estimated to some extent whether the increase type or the decrease type is selected for the speed response automatic adjustment. However, if the user is not familiar with the information, the user may not know whether to select the increasing type or the decreasing type, or may be unsure of the judgment. Therefore, in this embodiment, the automatic increase speed response adjustment according to the first embodiment is performed, and when the adjustment is not successful, the automatic decrease adjustment is automatically performed according to the second embodiment. An example of migration is shown. Thereby, the speed response gain can be automatically adjusted for the user.

  The incremental automatic adjustment of the third embodiment may be performed instead of the incremental automatic adjustment of the first embodiment, or the fourth implementation may be performed instead of the decreasing automatic adjustment of the second embodiment. An example reduced automatic adjustment may be performed. The order of increasing type and decreasing type may be changed.

  FIG. 9 shows a flowchart of the fifth embodiment.

  The start is an incremental speed response automatic adjustment. An initial value set in advance is set as the speed response gain (S1). Next, after starting operation (S2), it is determined whether the motor current is less than the overload current set value (S3). If it is less, continue driving. If it is equal to or higher than the overload current set value, the operation is stopped (S4), and after waiting for a predetermined time (S5), it is determined whether the total number of operations or the number of re-operations is equal to or less than the predetermined number of operations (S6). If it is less than or equal to the predetermined number, the speed response gain is increased by a predetermined value (S7), and the operation is started again. When this cycle is repeated and the number of operations exceeds the predetermined number of times (NO in S6), the process proceeds to a decrease type speed response automatic adjustment.

  First, the initial speed response gain value used at the first time of the incremental speed response automatic adjustment is set (S8). Similarly to the above, after the operation is started (S9), the operation is continued when the overload current set value is determined to be less than the overload current set value (S10). If it is equal to or higher than the overload current set value, the operation is stopped (S11), and after waiting for a predetermined time (S12), it is determined whether the total number of operations or the number of re-operations is less than the predetermined number of operations (S13). If it is less than or equal to the predetermined number, the speed response gain is decreased by a predetermined value (S14), and the operation is started again. This cycle is repeated until it becomes less than the overload current set value. If the number of operations exceeds the predetermined number, the adjustment is not completed and the process is terminated (S15).

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

DESCRIPTION OF SYMBOLS 1 ... Three-phase alternating current power supply 2 ... Motor control apparatus 3 ... Converter part 4 ... Smoothing capacitor 5 ... Inverter part 6 ... Current detector 7 ... Motor 8 ... Drive circuit 9 ... Load 10 ... Control part 11 ... Speed control part 12 ... Current Control unit 13 ... speed estimation unit 14 ... PWM control unit 15 ... speed response gain adjustment unit 16 ... overload determination unit

Claims (9)

A current detection unit that detects a motor current supplied to the motor and generates a current detection signal;
A control unit for controlling the motor using the current detection signal,
The controller is
A speed controller for controlling the speed of the motor based on a speed response gain;
A speed response gain adjusting unit for adjusting the speed response gain;
A determination unit that determines whether or not the motor current is greater than or equal to a set value,
The control unit controls the motor based on an input speed response gain, and stops the motor control when the motor current is equal to or greater than the set value, and the speed response gain used in the control unit The motor control device is characterized by repeating the cycle of changing and re-controlling until the motor current does not exceed the set value. The motor control device according to claim 1,
The control unit increases the speed response gain by a predetermined value when changing the speed response gain used in the control unit. The motor control device according to claim 1,
The said control part reduces the said speed response gain by predetermined value, when changing the speed response gain currently used by the said control part, The motor control apparatus characterized by the above-mentioned. The motor control device according to claim 1,
The control unit increases the speed response gain by a predetermined ratio when changing the speed response gain used in the control unit. The motor control device according to claim 1,
The said control part reduces the said speed response gain by a predetermined ratio, when changing the speed response gain currently used by the said control part, The motor control apparatus characterized by the above-mentioned. The motor control device according to claim 1,
The control unit controls the motor based on the input speed response gain, and when the motor current is equal to or greater than the set value, stops the control of the motor and uses the speed response used by the control unit. Repeating the first cycle of increasing the gain by a first predetermined value or a first predetermined percentage and re-controlling,
A second cycle in which, when the number of times of the first cycle exceeds a predetermined number, the speed response gain used in the control unit is re-controlled by decreasing to a second predetermined value or a second predetermined ratio. Is repeated until the motor current does not exceed the set value. The motor control device according to claim 1,
The control unit controls the motor based on the input speed response gain, and when the motor current is equal to or greater than the set value, stops the control of the motor and uses the speed response used by the control unit. Repeating the first cycle of decreasing the first predetermined value or the first predetermined ratio and re-controlling the gain;
A second cycle in which, when the number of times of the first cycle exceeds a predetermined number, the speed response gain used in the control unit is re-controlled by increasing the second predetermined value or a second predetermined rate. Is repeated until the motor current does not exceed the set value. A motor control method in a motor control device comprising: a current detection unit that detects a motor current supplied to a motor and generates a current detection signal; and a control unit that controls the motor using the current detection signal. ,
The control unit controls the motor based on an input speed response gain, determines whether the motor current is greater than or equal to a set value, and if the motor current is greater than or equal to the set value, A motor control method characterized by repeating a cycle of stopping control and changing a speed response gain used in the control unit and performing control again until the motor current does not exceed the set value. A current detection unit that detects a current supplied to the motor and generates a current detection signal;
A control unit for controlling the motor based on the current detection signal,
The controller is
A speed control unit that generates a torque command based on the speed command, the speed feedback signal, and the speed response gain;
A current control unit that generates a voltage command based on the torque command and the current detection signal;
A PWM controller that outputs a PWM signal for driving the motor based on the voltage command and the speed feedback signal;
A speed estimation unit that generates the speed feedback signal based on the voltage command and the current detection signal;
A speed response gain adjusting unit for adjusting the speed response gain;
An overload determination unit that determines whether or not the motor current is equal to or greater than an overload current set value;
When the overload determination unit determines that the motor current is equal to or greater than the overload current set value, the PWM control unit stops outputting the PWM signal, and the speed response gain adjustment unit adjusts the speed response gain. The speed control unit generates a new speed response gain, the speed control unit generates a new torque command based on the new speed response gain, and the current control unit generates a new voltage based on the new torque command. Generating a command, and the PWM control unit outputs a new PWM signal based on the new voltage command until the motor current does not exceed the overload current set value. Motor control device.

Images