TWI774069B - Actuating apparatus and driving method thereof - Google Patents

Abstract

An actuating apparatus includes an alternative current (AC) motor and a driver. The AC motor receives a driving voltage. The driver switches between a first mode and a second mode according to a command signal, and generates a torque command according to a mechanical command. The driver generates a current voltage command according to the torque command, a setting magnetic flux, a setting voltage margin and a previous voltage command, and generates the driving voltage according to the current voltage command. In the first mode, the driver sets the setting voltage margin to a first voltage margin according to the command signal, and generates the setting magnetic flux according to the mechanical command and a rotating velocity information of the AC motor. In the second mode, the driver sets the setting voltage margin to a second voltage margin according to the command signal. The setting magnetic flux equals a rated magnetic flux.

Description

Actuating device and driving method thereof

The present invention relates to an actuating device and a driving method thereof, and more particularly, to an actuating device and a driving method thereof which can improve performance and efficiency.

In the energy-saving control of induction motors in the past, most of the operating points of the motor were calculated in different ways, and the switching of control modes was not adjusted in time for different use environments and in the process of processing. Therefore, the applicable environment will be limited, and it may only be applicable to no-load or low-load environments. If there is a light load and high precision environment is required during the entire operation, the optimal response will not be provided due to the low operating flux. In addition, in the design of the voltage margin, the method of switching the voltage margin during processing has not been proposed in the past, so in order to have good acceleration and deceleration performance, the voltage margin is usually set lower. However, if finishing is required at this time, it will easily reach the upper limit of the voltage due to insufficient voltage margin, resulting in poor stability.

In the past patents given by the upper controller to control the energy-saving function, they were mostly applied to the processing of multiple workpieces or multiple processing steps. For example, the department The separate motor is in some processing steps, the original state is kept in standby, and the power-off command is inserted before starting to standby, and it is restarted until it needs to start processing, so as to save energy consumption during standby, but such This approach makes it impossible to save energy during machining operations.

In view of this, the present invention provides an actuating device and a driving method thereof, which can dynamically switch between different modes during processing, while improving performance, energy saving and stability.

The actuating device of the present invention includes an AC motor and a driver. The AC motor receives the drive voltage. The driver drives the AC motor. The driver switches between the first mode and the second mode according to the command signal, and generates a torque command according to the mechanical command. The driver generates the current voltage command according to the torque command, the set magnetic flux, the set voltage margin and the previous voltage command, and generates the driving voltage according to the current voltage command. In the first mode, the driver is used to: set the first voltage margin as the set voltage margin according to the command signal, and generate the set magnetic flux according to the mechanical command and the rotational speed information of the AC motor. Wherein, in the second mode, the driver is used for: setting the second voltage margin as the setting voltage margin according to the command signal. wherein the first voltage margin is smaller than the second voltage margin, and the set magnetic flux is made equal to the rated magnetic flux.

The driving method of the present invention is used to drive the AC motor, including: switching between the first mode and the second mode according to the command signal; generating the torque command according to the mechanical command; according to the torque command, setting the magnetic flux, setting the voltage margin and the previous voltage command to generate the current voltage command; and generating according to the current voltage command to drive the AC The drive voltage of the flow motor. In the first mode, the first voltage margin is set as the set voltage margin according to the command signal, and the set magnetic flux is generated according to the mechanical command and the rotational speed information of the AC motor. In the second mode: the second voltage margin is set as the set voltage margin according to the command signal, wherein the first voltage margin is smaller than the second voltage margin, and the set magnetic flux is equal to the rated magnetic flux.

Based on the above, the actuating device proposed by the present invention can control the driver to switch between the first mode and the second mode according to the command signal by setting the AC motor and the driver, and matching the driving method, and then according to the mechanical command to generate the torque command, so as to control the torque according to the torque command. The command, the set magnetic flux, the set voltage margin and the previous voltage command generate the current voltage command, and generate the driving voltage according to the current voltage command to drive the AC motor. In different processing environments, the switching of control modes can be adjusted in real time to effectively improve performance, energy saving and stability.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

100: Actuator

101, 301_1, 301_2: drives

102, 302_1, 302_2: AC motor

303_1, 303_2: External host

401~404: Waveform

CS: command signal

Cmd: Mechanics Command

Id, Iq: current information

S210~S260, S510~S570: Steps

t1~t4: time

Tcmd: torque command

V1~V5, Vout: Voltage

Vdq(t1), Vdq(t2): Voltage command

Verr: Speed Error Information

VH, VL: voltage margin

Φ: set magnetic flux

FIG. 1 is a schematic diagram of a system of an actuating device according to an embodiment of the present invention.

FIG. 2 is a flow chart illustrating the operation of the actuating device according to the embodiment of the present invention.

FIG. 3A is a schematic diagram illustrating an operation of a smart energy saving mode according to an embodiment of the present invention.

FIG. 3B is a schematic diagram of the operation of the refinement mode according to an embodiment of the present invention.

4A and 4B are action waveform diagrams of the actuating device according to different embodiments of the present invention.

FIG. 5 is a block diagram illustrating a driving method according to an embodiment of the present invention.

Please refer to FIG. 1 , which is a schematic diagram of a system of an actuating device according to an embodiment of the present invention. In FIG. 1 , the actuating device 100 includes a driver 101 and an AC motor 102 . In this embodiment, the actuating device 100 can be coupled to an external host. The external host is used to control the actuating device 100 to perform processing control actions. The AC motor 102 of this embodiment may be an induction motor.

In this embodiment, the external host may be a host controller or an external device with input and output functions, and there is no fixed limit. The driver 101 can be an arithmetic unit with computing capabilities, such as a central processing unit (CPU), or other programmable general-purpose or special-purpose microprocessors (Microprocessors), digital signal processors (Digital Signal Processors) Signal Processor (DSP), Programmable Controller, Application Specific Integrated Circuits (ASIC), Programmable Logic Device (PLD), or other similar devices or combinations of these devices, which may Load and execute the computer program to complete the corresponding operation function. In one embodiment, the driver can also implement various operation functions in the form of a hardware circuit, and the detailed steps and implementations thereof can be adequately taught, suggested and implemented by common knowledge in the technical field.

Regarding the operation of the actuating device 100 of the present embodiment, please refer to FIG. 1 and FIG. 2 at the same time, wherein FIG. 2 illustrates the action flow of the actuating device according to the present embodiment of the present invention. picture. In this embodiment, steps S210 and S220 may be performed by an external host, steps S230 to S250 may be performed by the driver 101 , and step S260 may be performed by the AC motor 102 .

In step S210, the external host starts to execute the machining operation of the load. The external host sends the command signal CS and the mechanical command Cmd to the driver 101 in step S220.

In this embodiment, the command signal CS can be provided by an external electronic device. The command signal CS may be a mode switching command provided by the input output (I/O) function of the external host. In other embodiments, the command signal CS may be a machining instruction (eg, G/M code) in a computer numerical control software (Computer Numerical Control, CNC). The mechanical command Cmd may be a speed command, a position command, an acceleration command, etc. or other commands related to the motion of the motor. The interface for signal transmission can be any input interface, and there is no fixed limit.

In this embodiment, in step S230, the driver 101 can switch the working mode between the first mode and the second mode according to the command signal CS. The first mode and the second mode may be a smart energy-saving mode and a fine-tuning mode, respectively.

Incidentally, the driver 101 in the embodiment of the present invention can also work in other modes, and is not limited to only the above two modes. For example, the driver 101 can also work in the normal mode (third mode) according to the command signal CS, wherein the power consumption of the actuating device 100 in the smart energy-saving mode can be lower than that in the same rotational speed information of the AC motor 102 . Power consumption in normal mode.

In the smart energy saving mode, the driver 101 goes through step S241 to The command signal CS makes the set voltage margin equal to the first voltage margin, and generates a torque command according to the mechanical command Cmd, and then generates a set magnetic flux according to the torque command and the rotational speed information of the AC motor 102 .

In the fine trimming mode, the driver 101 makes the set voltage margin be the second voltage margin according to the command signal CS through step S242, and set the set magnetic flux to be the rated magnetic flux.

In this embodiment, in step S250 , the driver 101 calculates and generates the driving voltage Vout, and then outputs the driving voltage Vout to the AC motor 102 . In step S260 , the AC motor 102 operates according to the driving voltage Vout output by the driver 101 .

In this embodiment, the power consumption of the actuating device 100 in the smart energy saving mode may be lower than the power consumption in the fine repairing mode under the same rotation speed information of the AC motor 102 .

The detailed process of generating the driving voltage Vout by the driver 101 will be described in detail in subsequent implementation methods.

In this embodiment, the actuating device 100 can also select an applicable processing mode according to various requirements of different processing situations. Please refer to Table 1 below. Table 1 shows the applicable processing modes according to the needs of various situations under different loads and different processing application scenarios. Wherein, when the actuating device 100 performs the cutting action of the object, the light load refers to the situation where the external force is relatively small, such as a relatively light cutting force, and the heavy load refers to the situation that requires a larger cutting force and the like. When doing rough machining, you can use the smart energy-saving mode to reduce unnecessary excitation current and achieve energy-saving effect at light load. Under heavy load, the acceleration and deceleration performance of the AC motor 102 can be improved by reducing the set voltage margin. On the contrary, when the load is light and the finishing process is performed, the finishing mode can be used to provide a sufficient set voltage margin and improve the working stability of the AC motor 102 . Wherein, the classification of precision and load in Table 1 is only an exemplary example, and is not intended to limit the scope of implementation of the present invention.

Please note that in this embodiment, the actuating device 100 can perform the above-mentioned switching between the smart energy saving mode and the fine-tuning mode during processing. For example, in one embodiment, the original machining flow is to perform lateral rough turning (roughing) first, and then perform finishing. If the implementation method of the present invention is adopted, the intelligent energy-saving mode can be selected first before starting the processing to finishing. During rough machining, since the set voltage margin can be adjusted to a lower level, the AC motor 102 can have better acceleration and deceleration performance during operation, and power consumption can be saved to achieve the effect of energy saving. Then, before performing the finishing, the actuating device 100 may receive the command signal CS to switch to the finishing mode. During the finishing process, since the set voltage margin can be increased and the AC motor 102 can be controlled to work at a rated operating point, the AC motor 102 can have higher stability during operation to meet the needs of finishing. Finally, after finishing finishing, the actuating device 100 can also receive the command signal CS again to switch back to the smart energy saving mode.

It can be known from the above description that the actuating device 100 according to the embodiment of the present invention can be switched between the smart energy saving mode and the fine repairing mode according to the actual processing requirements, so as to save power consumption, improve processing performance and The effect of improving the working stability of the AC motor 102 can effectively improve the overall efficiency of the system.

For details of the action of the smart energy saving mode in the embodiment of FIG. 2 of the present invention, please refer to FIG. 3A . FIG. 3A is a schematic diagram illustrating an operation of a smart energy saving mode according to an embodiment of the present invention. In FIG. 3A , the external host 303_1 is used for sending the command signal CS and the mechanical command Cmd to the driver 301_1 , and the driver 301_1 is used for sending the driving voltage Vout to drive the AC motor 302_1 .

In this embodiment, the driver 301_1 makes the set voltage margin be the first voltage margin VL according to the command signal CS, and generates the rotational speed error information Verr according to the mechanical command Cmd and the rotational speed information of the AC motor 302_1. In this embodiment, the mechanical command Cmd may be a speed command.

On the other hand, the first voltage margin VL may be the difference between the maximum driving voltage that the driver 301_1 can apply to the AC motor 302_1 and the voltage value at which the driver 301_1 determines to enter the field weakening control. When the mechanical command Cmd is the speed command, the rotational speed error information Verr may be the difference between the mechanical command Cmd and the current rotational speed information of the AC motor 302_1. When the mechanical command Cmd is the position command, the rotational speed error information Verr may be the difference between the position command and the position feedback, and the speed command obtained after calculation.

The driver 301_1 generates a torque command Tcmd according to the rotational speed error information Verr, and then generates a set magnetic flux Φ and torque shaft current information according to the torque command Tcmd Iq. In this embodiment, the set magnetic flux Φ may be an energy-saving magnetic flux.

At the first time point t1, the driver 301_1 generates the excitation axis current information Id according to the first voltage margin VL and the set magnetic flux Φ, and generates the current voltage command Vdq ( t1).

Then, at the second time point t2 after that, the voltage command Vdq(t1) becomes the previous voltage command. At this time, the driver 301_1 generates the current voltage command Vdq ( t2 ) according to the excitation shaft current information Id, the torque shaft current information Iq and the previous voltage command Vdq ( t1 ).

On the other hand, taking the second time point t2 as an example, the driver 301_1 can determine whether the current voltage command Vdq(t2) is greater than the maximum driving voltage that the driver 301_1 can apply to the AC motor 302_1, and at the current voltage command Vdq(t2) ) is greater than the maximum driving voltage, make the current driving voltage Vout be the maximum driving voltage.

In this embodiment, the driver 301_1 generates the driving voltage Vout according to the current voltage command Vdq(t2), and is used to drive the AC motor 302_1. Incidentally, the driver 301_1 can compare the current voltage command Vdq(t2) with the maximum driving voltage of the driver 301_1 to generate the driving voltage Vout. On the other hand, the driver 301_1 can select the lower voltage value between the current voltage command Vdq(t2) and the maximum driving voltage of the driver 301_1 as the driving voltage Vout.

In this embodiment, when the actuating device 100 is under a light-load processing situation, the driver 301_1 can be switched to a smart energy-saving mode, so that the AC motor 302_1 can work at different rotational speeds with energy-saving effects. For example, the rotation speed of the AC motor 302_1 can be set at 150~6000 revolutions (RPM), when the driver 301_1 switches off After switching to the smart energy-saving mode, the value of the working current of the AC motor 302_1 can be reduced by 44%~91% compared with the normal mode, the value of the operating voltage can be reduced by 63%~91% compared with the normal mode, and the value of the operating power can also be lower than the normal mode. The mode is reduced by 80%~99%, which can successfully achieve the effect of energy saving.

Please refer to FIG. 3B for details of the operation of the refinement mode in the embodiment of FIG. 1 of the present invention. FIG. 3B is a schematic diagram of the operation of the refinement mode according to an embodiment of the present invention. 3B and FIG. 3A have similar operation procedures, the difference is that, in this embodiment, the driver 301_2 will set the voltage margin to the second voltage margin VH according to the command signal CS, and generate the rotational speed error information Verr according to the mechanical command Cmd , and let the set magnetic flux Φ be the rated magnetic flux. It is worth noting that in the refinement mode, the set magnetic flux Φ is independent of the mechanical command Cmd. In this embodiment, the mechanical command Cmd may be a speed command, and the second voltage margin VH may be a relatively high voltage margin (the second voltage margin VH>the first voltage margin VL). For the rest of the implementation methods, reference may be made to the action description of FIG. 3A , and details are not described herein. In this embodiment, because the set voltage margin of the driver 301_2 can be increased, the AC motor 302_2 can have better stability during operation.

Regarding the selection of the set voltage margin when the above-mentioned actuating device operates in the smart energy-saving mode and the fine-tuning mode, please refer to FIG. 4A and FIG. 4B at the same time. 4A and 4B are action waveform diagrams of the actuating device according to different embodiments of the present invention.

Please refer to FIG. 4A. In Figure 4A, the driver has a maximum drive voltage V3. When the AC motor operates under the condition of high voltage margin, the operating voltage is shown as waveform 401 . And when the AC motor works under the condition of low voltage margin, the working voltage such as waveform 402 is shown.

When the waveform 401 and the waveform 402 reach the time t1, the AC motor both reaches the rated speed. According to the waveform 401 (under the condition of high voltage margin), the operating voltage is maintained at the operating voltage V1 after time t1. According to the waveform 402 (under the condition of low voltage margin), the voltage saturation is reached at time t2, and the operating voltage is maintained at the operating voltage V2 after time t2. Wherein, the working voltages V1 and V2 are both smaller than the maximum driving voltage V3, and the working voltage V1<the working voltage V2. Since the working voltage V2 > the working voltage V1, after the time t1, the low voltage margin will have better acceleration. For example, the low voltage margin can reach the maximum speed at the time t3, while the high voltage margin will take time The maximum rotational speed can only be reached at t4, where time t3 occurs earlier than time t4.

Please note that in this embodiment, on the premise that the working voltage of the AC motor will be stable during the acceleration process, and on the premise that the working voltage V1 < the working voltage V2, the waveform 401 has a relatively high voltage margin relative to the waveform 402 .

Next, please refer to FIG. 4A and FIG. 4B at the same time. FIG. 4B is the operation point after time t2 in FIG. 4A . The waveforms 403 and 404 are the voltage waveform changes when subjected to external disturbance. The waveform 403 shows that the AC motor operates under the condition of high voltage margin, and the AC motor is maintained at the rated voltage. At the highest speed, its working voltage is V4. Waveform 404 shows that when the AC motor operates under the condition of low voltage margin and the AC motor is maintained at the rated maximum speed, its operating voltage is V5. In the fine-tuning mode, because the voltage margin is high, when it is disturbed by external force, it will not be limited by the upper voltage limit (V3), and there can be enough voltage for correction; while the low voltage margin is easy to reach limited by the drive maximum voltage.

Therefore, based on the above-mentioned control embodiments of the smart energy-saving mode and the fine-tuning mode, the actuating device of the present invention can switch the working mode between the smart power-saving mode and the fine-tuning mode according to the command signal and the mechanical command sent by the external host. In the smart energy-saving mode, the set voltage margin of the driver can be adjusted to a low voltage margin, so that the AC motor has better acceleration and deceleration performance during operation. On the other hand, the torque command can be generated according to the mechanical command to determine the set magnetic flux of the optimal efficiency control, which can reduce the unnecessary loss caused by the excitation current under light load, and achieve the effect of improving performance and saving energy. In the refinement mode, the set voltage margin of the driver can be adjusted to a high voltage margin to reduce the voltage when entering the field weakening control, so that the AC motor has better stability during operation. It is less affected by the maximum drive voltage of the driver. On the other hand, before the driving voltage of the driver reaches saturation, the set magnetic flux can be set to the rated magnetic flux to control the AC motor under the rated excitation current, so that the AC motor has a better working response.

Please refer to Figure 5. FIG. 5 is a block diagram illustrating a driving method according to an embodiment of the present invention. The driving method thereof can be realized by the aforementioned actuating device. In step S510, the actuating device receives the command signal and the mechanical command. And in step S520, the working mode can be switched between the first mode and the second mode according to the command signal.

In this embodiment, in step S520, when switching to the first mode according to the command signal, step S530 is entered, and step S530 includes step S531 and step S532. In step S531, the set voltage margin may be the first voltage margin, and in step S532, the set magnetic flux is generated according to the mechanical command and the rotational speed information of the AC motor.

In this embodiment, in step S520, when switching to the second mode according to the command signal, it will enter into step S540, and step S540 includes step S541 and step S542. In step S541, the set voltage margin may be the second voltage margin, and in step S542 the set magnetic flux may be the rated magnetic flux.

After step S530 or step S540 is executed, step S550 is entered to generate a torque command according to the mechanical command. And in step S560, the current voltage command is generated according to the torque command, the set magnetic flux, the set voltage margin and the previous voltage command. Finally, in step S570, a driving voltage for driving the AC motor is generated according to the current voltage command.

The implementation details of the above steps have been described in detail in the foregoing embodiments, and will not be repeated here.

To sum up, the actuating device proposed by the present invention can be applied to induction motors and different processing situations by opening the driver for switching control modes, so that the external device can dynamically switch the intelligent energy-saving mode and fine-tuning during processing. model. Among them, the smart energy-saving mode can reduce the set voltage margin and have good acceleration and deceleration performance. When applied under different loads, the set magnetic flux can also be reduced to save energy. When used in transient heavy loads and acceleration and deceleration requirements, it is also possible to instantly adjust and set the magnetic flux control operation to exceed the rated point of the motor with lower losses. On the other hand, the fine-tuning mode can improve the set voltage margin and can be used in low-load and high-stability environments. Therefore, the actuating device and the driving method proposed by the present invention can simultaneously improve the performance, energy saving and stability of machining operations by dynamically switching the above two driver modes.

Although the present invention has been disclosed above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

S210~S260: Steps

Claims (10)

An actuating device comprising: an AC motor, receiving a driving voltage; A driver drives the AC motor, the driver switches between a first mode and a second mode according to a command signal, generates a torque command according to a mechanical command, and generates a torque command according to the torque command, a set magnetic flux, a set voltage margin and a previous voltage command to generate a current voltage command, and generate the driving voltage according to the current voltage command, Wherein, in the first mode, the driver is used to: setting a first voltage margin as the set voltage margin according to the command signal; and generating the set magnetic flux according to the mechanical command and the rotational speed information of the AC motor; Wherein, in the second mode, the driver is used to: setting a second voltage margin as the set voltage margin according to the command signal, wherein the first voltage margin is smaller than the second voltage margin; and The set magnetic flux is made equal to a rated magnetic flux. The actuating device of claim 1, wherein the driver is configured to generate a rotational speed error information according to the mechanical command and rotational speed information of the AC motor, and generate the torque command according to the rotational speed error information. The actuating device of claim 1, wherein the driver obtains an excitation shaft current information according to the set voltage margin, the set magnetic flux, and the previous voltage command, and obtains a torque shaft current information according to the torque command, The current voltage command is generated according to the excitation shaft current information and the torque shaft current information. The actuating device of claim 1, wherein the driver further comprises determining whether the driving voltage generated by the current voltage command is greater than a maximum driving voltage, and when the driving voltage is greater than the maximum driving voltage, making the driving voltage equal to the maximum drive voltage. The actuating device of claim 1, wherein corresponding to the same rotational speed information of the AC motor, the power consumption of the actuating device in the first mode is less than or equal to the power consumption in the second mode. The actuating device as claimed in claim 1, wherein the driver is further operated in a third mode which is a normal mode according to the command signal, wherein corresponding to the same rotational speed information of the AC motor, the actuating device operates in the first mode The power consumption in the mode is less than the power consumption in this third mode. A driving method for driving an AC motor, comprising: switching between a first mode and a second mode according to a command signal; generating a torque command according to a mechanical command; generating a current voltage command according to the torque command, a set flux, a set voltage margin, and a previous voltage command; and generating a driving voltage for driving the AC motor according to the current voltage command, Among them, in this first mode: setting a first voltage margin as the set voltage margin according to the command signal; and The set magnetic flux is generated according to the mechanical command and the rotational speed information of the AC motor, In this second mode: setting a second voltage margin as the set voltage margin according to the command signal, wherein the first voltage margin is smaller than the second voltage margin; and The set magnetic flux is made equal to a rated magnetic flux. The driving method according to claim 7, wherein the step of generating the torque command according to the mechanical command comprises: generating a rotational speed error information according to the mechanical command and rotational speed information of the AC motor; and The torque command is generated according to the rotational speed error information. The driving method of claim 7, wherein the step of generating the current voltage command according to the torque command, the set magnetic flux, the set voltage margin and the previous voltage command comprises: obtaining an excitation shaft current information according to the set voltage margin, the set flux, and the previous voltage command; and A torque shaft current information is obtained according to the torque command. The driving method according to claim 7, further comprising: determining whether the driving voltage generated by the current voltage command is greater than a maximum driving voltage; and When the driving voltage is greater than the maximum driving voltage, the driving voltage is made equal to the maximum driving voltage.

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