A method, apparatus, and medium for controlling full speed range operation of a molecular pump

Abstract

The application discloses a kind of molecular pump full speed domain operation control method, equipment and medium, it is related to molecular pump operation control field, its technical solution main point is: receiving control instruction, and judging control instruction is start instruction or stop instruction;When control instruction is start instruction, the current speed of molecular pump is obtained, according to the size relationship of current speed and first speed condition, execute quick speed reduction algorithm, sliding mode observation algorithm and current frequency control algorithm, to make molecular pump run to rated speed;Wherein, first speed condition includes target speed, low critical speed and three kinds of conditions that speed is zero;When control instruction is stop instruction, the current speed of molecular pump is obtained, according to the size relationship of current speed and second speed condition, execute quick speed reduction algorithm and sliding mode observation algorithm, to make the speed of molecular pump drop to zero;Wherein, the second speed condition includes three kinds of conditions that speed is zero, low critical speed and preset speed before stop.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of molecular pump operation control, and more particularly, to a molecular pump full-speed range operation control method, device and medium. BACKGROUND

[0002] A molecular pump, also known as a turbo molecular pump (TMP), has a maximum rotation speed of 90,000 revolutions per minute and is a key device indispensable in the field of modern vacuum technology application, which is specially used to generate and maintain a high vacuum (HV) to ultra-high vacuum (UHV) environment (usually ranging from 10 -3 Pa to 10 -10 Pa or even lower). It overcomes the limitation of a traditional mechanical pump (such as a scroll pump, a screw pump) in which the pumping speed drops sharply at low pressure, and is the basis for advanced fields such as mass spectrometry, semiconductor manufacturing, coating process, surface science research, particle accelerator, etc.

[0003] However, the operation control of the super-speed motor of the molecular pump is different from that of the ordinary motor, and it is necessary to start stably and reliably at any speed within the rated speed range and to output the speed data in the whole process of starting speed-up and natural speed-down. Therefore, the full-speed range operation control of the molecular pump is one of the key challenges affecting its reliable operation.

[0004] In the prior art, the molecular pump in the whole machine system may receive a start or stop command at any time. When the rotation speed is low, the back electromotive force signal is too small, and the sliding mode observation algorithm cannot effectively estimate the rotation speed and rotor position of the molecular pump motor, so the molecular pump cannot be directly started. The conventional method can use a high-frequency injection algorithm and a flux linkage control algorithm to estimate the rotation speed and rotor position, and switch to the sliding mode observation algorithm when a certain rotation speed is reached. However, due to the fact that the salient pole ratio of the surface-mounted permanent magnet synchronous motor used by the molecular pump is not obvious, the effect of the high-frequency injection algorithm is limited, and high-frequency injection will bring new noise and vibration, affecting the performance of the product, and 100% start success cannot be achieved. Furthermore, the flux linkage control algorithm will also cause strong initial vibration during low-speed start and poor load disturbance resistance, and both methods cannot guarantee 100% start success. In addition, the rated rotation speed of the molecular pump is 90,000 revolutions per minute, which belongs to the super-speed operation range. In order to avoid the exposure of the atmosphere when the molecular pump is closed before the pre-stage pump is completely stopped, which causes the rubbing or damage of the moving vane components, it is necessary to output the rotation speed data in the whole process of speed-down stop. Due to the large operation speed range, the complexity of the back electromotive force signal processing circuit will be significantly increased, the reliability of the product will be reduced, and the miniaturization design of the product will be affected. SUMMARY

[0005] The application aims to provide a molecular pump full-speed range operation control method, device and medium, and solve the problem that the control method provided by the prior art cannot realize reliable operation control of the molecular pump start-up speed-up and shutdown speed-down full-speed range.

[0006] The above technical purposes of the application are achieved by the following technical solutions:

[0007] In a first aspect, the application provides a molecular pump full-speed range operation control method, which comprises:

[0008] receiving a control instruction and determining whether the control instruction is a start-up instruction or a shutdown instruction;

[0009] When the control instruction is the start-up instruction, the current speed of the molecular pump is obtained, and the fast speed-down algorithm, the sliding mode observation algorithm and the current frequency control algorithm are executed according to the size relationship between the current speed and the first speed condition, so as to make the molecular pump run at the rated speed; wherein the first speed condition includes three conditions of the target speed, the low critical speed and the zero speed.

[0010] When the control instruction is the shutdown instruction, the current speed of the molecular pump is obtained, and the fast speed-down algorithm and the sliding mode observation algorithm are executed according to the size relationship between the current speed and the second speed condition, so as to make the speed of the molecular pump drop to zero; wherein the second speed condition includes three conditions of the preset speed before shutdown, the low critical speed and the zero speed.

[0011] In an implementation scheme, the fast speed-down algorithm, the sliding mode observation algorithm and the current frequency control algorithm are executed according to the size relationship between the current speed and the first speed condition, so as to make the speed of the molecular pump run at the rated speed, which comprises:

[0012] When the current speed is less than the target speed and less than the low critical speed, the fast speed-down algorithm is started, the first current value when the fast speed-down algorithm is started is collected, and the second coefficient for representing the speed is obtained according to the ratio of the current speed and the first current value;

[0013] The second current value in the process of starting the fast speed-down algorithm is collected, and the second actual speed satisfying the two speed conditions of the target speed and the low critical speed is obtained according to the product of the second current value and the second coefficient.

[0014] When the second actual speed is zero, the current frequency control algorithm is started to control the start-up of the molecular pump, and when the running speed of the molecular pump controlled by the current frequency control algorithm is greater than the low critical speed, the sliding mode observation algorithm is switched to estimate the motor speed and the rotor position of the molecular pump in real time, until the rated speed is reached, and the start-up control of the molecular pump is ended.

[0015] In an implementation scheme, the application further comprises:

[0016] When the current rotation speed is greater than or equal to the target rotation speed, a fast speed reduction algorithm is started, a first current value when the fast speed reduction algorithm is started is collected, and a first coefficient for representing the rotation speed is obtained according to a ratio of the current rotation speed and the first current value; wherein the first coefficient is greater than the second coefficient;

[0017] A second current value in the process of starting the fast speed reduction algorithm is collected, a first actual rotation speed satisfying the target rotation speed is obtained according to a product of the second current value and the first coefficient, and the first actual rotation speed is taken as the current rotation speed when the start instruction is received.

[0018] In an implementation scheme, the method further comprises:

[0019] If the current rotation speed is greater than or equal to the low critical rotation speed, back electromotive force data at the current time is read;

[0020] The motor rotation speed and the rotor position of the molecular pump at the current time are calculated according to the back electromotive force data, and then the sliding mode observation algorithm is switched to estimate the electronic rotation speed and the rotor position of the molecular pump in real time, and the running continues until the rated rotation speed.

[0021] In an implementation scheme, if the second actual rotation speed is not zero, the fast speed reduction algorithm is continuously executed until the second actual rotation speed is reduced to zero;

[0022] If the running rotation speed of the molecular pump controlled by the current frequency control algorithm is less than or equal to the low critical rotation speed, the current frequency control algorithm is continuously executed until the running rotation speed of the molecular pump controlled by the current frequency control algorithm is greater than the low critical rotation speed.

[0023] In an implementation scheme, when the control instruction is a stop instruction, the current rotation speed of the molecular pump is obtained, the fast speed reduction algorithm and the sliding mode observation algorithm are executed according to the size relationship between the current rotation speed and the second rotation speed condition, so that the rotation speed of the molecular pump is reduced to zero, comprising:

[0024] When the current rotation speed is less than the preset rotation speed before stopping and less than the low critical rotation speed, the fast speed reduction algorithm is started, a first current value when the fast speed reduction algorithm is started is collected, and a fourth coefficient for representing the rotation speed is obtained according to a ratio of the current rotation speed and the first current value;

[0025] A second current value in the process of starting the fast speed reduction algorithm is collected, a first actual rotation speed satisfying the target rotation speed is obtained according to a product of the second current value and the first current value, and the first actual rotation speed is taken as the current rotation speed when the start instruction is received.

[0026] When the fourth actual rotation speed is zero, the stop control of the molecular pump ends.

[0027] In an implementation scheme, the method further comprises:

[0028] When the current rotating speed is greater than or equal to the preset rotating speed before shutdown, a fast rotating speed reduction algorithm is started, a first current value when the fast rotating speed reduction algorithm is started is collected, a third coefficient for representing the rotating speed is obtained according to a ratio of the current rotating speed and the first current value, and the third coefficient is greater than the fourth coefficient.

[0029] A second current value in the process of starting the fast rotating speed reduction algorithm is collected, a third actual rotating speed satisfying the target rotating speed is obtained according to a product of the second current value and the third coefficient, and the third actual rotating speed is taken as the current rotating speed when the shutdown instruction is received.

[0030] In an implementation scheme, the method further comprises:

[0031] If the current rotating speed is greater than or equal to the low critical rotating speed, the counter electromotive force data at the current time is read.

[0032] The motor rotating speed and the rotor position of the molecular pump at the current time are calculated according to the counter electromotive force data until the current rotating speed is reduced to the low critical rotating speed.

[0033] In the second aspect of the present application, a control device applied to a molecular pump is provided, comprising a memory and a processor.

[0034] The memory is used for storing a computer program, and the computer program comprises program instructions.

[0035] The processor is used for executing the program instructions, so that the control device executes the steps of the molecular pump full speed domain operation control method provided in the first aspect of the present application.

[0036] In the third aspect of the present application, a computer readable storage medium is provided, and the computer readable storage medium comprises a computer program.

[0037] Compared with the prior art, the present application has the following beneficial effects:

[0038] 1. The application provides a full speed range operation strategy, first set a low critical speed (about 3% of rated speed), when receiving start instruction, if the current speed is lower than the low critical speed, then reduce to zero speed and then start using current frequency control algorithm, and then cut into sliding mode control algorithm, if the current speed is higher than the low critical speed, then directly start using sliding mode control algorithm; when receiving stop instruction, if the current speed is lower than the low critical speed, then quickly reduce to zero speed using fast speed reduction algorithm, if the current speed is higher than the low critical speed, then naturally reduce; during operation, if receiving start or stop instruction, and the current speed is lower than the low critical speed, then quickly reduce to zero speed using fast speed reduction algorithm. This method no longer needs complex observation algorithm, and can achieve 100% start success.

[0039] 2. The application also provides a molecular pump full speed range speed detection output strategy, when the speed is lower than the low critical speed, whether in start state or stop state, the speed of the molecular pump is represented by current coefficient using fast speed reduction method, when the speed is higher than the low critical speed, the speed of the molecular pump can be obtained according to back electromotive force, so as to realize full speed range speed detection output of the molecular pump. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0041] Figure 1 A flow chart of a molecular pump full speed range operation control method provided by the embodiments of the application;

[0042] Figure 2 A flow chart of a molecular pump full speed range operation control method provided by the embodiments of the application;

[0043] Figure 3 A start-stop test speed and current curve diagram of a molecular pump in static state provided by the embodiments of the application;

[0044] Figure 4 A start-stop test speed and current curve diagram of a molecular pump below low critical speed provided by the embodiments of the application;

[0045] Figure 5 A start-stop test speed and current curve diagram of a molecular pump above low critical speed provided by the embodiments of the application. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the application clearer, further detailed description will be made to the application in combination with embodiments and drawings, the illustrative embodiments of the application and the description thereof are only used to explain the application, and do not limit the application.

[0047] It is noted that the term "include" or "may include" used in various embodiments of the present application indicates the existence of the claimed function, operation, or element, and does not limit one or more functions, operations, or elements from being added. Also, as used in various embodiments of the present application, the terms "include", "have", and their conjugates merely indicate the presence of specific features, numbers, steps, operations, elements, components, or combinations thereof, and should not be construed as excluding the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0048] It is to be understood that terms such as "first", "second", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or an indicated number of technical features. Thus, features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically limited.

[0049] Please refer to Figure 1 , Figure 1 A flow chart of a molecular pump full-speed domain operation control method provided by an embodiment of the present application is shown in Figure 1 , which includes the following steps:

[0050] S101, a control instruction is received, and it is determined whether the control instruction is a start instruction or a stop instruction.

[0051] In this embodiment, receiving a control instruction and determining its type are common knowledge in the technical field, so this embodiment will not be described in detail.

[0052] S102, when the control instruction is a start instruction, the current speed of the molecular pump is obtained, and according to the size relationship between the current speed and the first speed condition, a fast speed reduction algorithm, a sliding mode observation algorithm, and a current frequency control algorithm are executed to make the molecular pump run at a rated speed; wherein the first speed condition includes three conditions of target speed, low critical speed, and zero speed.

[0053] In this embodiment, please refer to the left part of the flowchart in Figure 2 , which shows the control process when the control instruction is a start instruction, as follows:

[0054] When the current speed is less than the target speed and less than the low critical speed, the fast speed reduction algorithm is started, the first current value when the fast speed reduction algorithm is started is collected, and the second coefficient for representing the speed is obtained according to the ratio of the current speed to the first current value.

[0055] The second current value in the process of starting the fast speed reduction algorithm is collected, and the second actual speed satisfying the two speed conditions of the target speed and the low critical speed is obtained according to the product of the second current value and the second coefficient;

[0056] When the second actual speed is zero, the current frequency control algorithm is started to control the molecular pump, and when the running speed of the molecular pump controlled by the current frequency control algorithm is greater than the low critical speed, the sliding mode observation algorithm is switched to estimate the motor speed and rotor position of the molecular pump in real time until the rated speed is reached, and the starting control of the molecular pump ends.

[0057] Wherein, when the current speed is greater than or equal to the target speed, the fast speed reduction algorithm is started, the first current value in the process of starting the fast speed reduction algorithm is collected, and the first coefficient for representing the speed is obtained according to the ratio of the current speed to the first current value; wherein the first coefficient is greater than the second coefficient; the second current value in the process of starting the fast speed reduction algorithm is collected, and the first actual speed satisfying the target speed is obtained according to the product of the second current value and the first coefficient, and the first actual speed is taken as the current speed when the starting instruction is received.

[0058] Wherein, if the current speed is greater than or equal to the low critical speed, the back electromotive force data at the current time is read; the motor speed and rotor position of the molecular pump at the current time are calculated according to the back electromotive force data, and then the sliding mode observation algorithm is switched to estimate the motor speed and rotor position of the molecular pump in real time, and the running continues until the rated speed is reached.

[0059] Specifically, if the second actual speed is not zero, the fast speed reduction algorithm is continuously executed until the second actual speed is reduced to zero; if the running speed of the molecular pump controlled by the current frequency control algorithm is less than or equal to the low critical speed, the current frequency control algorithm is continuously executed until the running speed of the molecular pump controlled by the current frequency control algorithm is greater than the low critical speed.

[0060] In combination with the control process described above, the present embodiment takes Figure 2 as an example to describe in detail the full speed domain control process of the starting instruction. A low critical speed (about 3% of the rated speed) is set, and when the starting instruction is received, the current speed is first judged. If the current speed is lower than the low critical speed, it is reduced to zero speed and then started by the current frequency control algorithm. If the current speed is higher than the low critical speed, it is directly started in closed loop.

[0061] The specific implementation is as follows: if it is a starting instruction, the current speed ω is first obtained, and it is determined whether the current speed ω is less than the set target speed ω set If the current speed ω is greater than the set target speed ω set, the fast speed reduction algorithm is started, and the first current value I max The first coefficient for representing the speed is calculated k 1. Then, the second current value during the process of starting the fast speed reduction algorithm is collected i max The first coefficient k 1 and the second current value, the current first actual speed is calculated ω 1= k 1× i max At this time, after the speed reduction control of the fast speed reduction algorithm, the current speed can be quickly reduced to the set target speed ω set If the current speed ω is less than the set target speed ω set It is determined whether the current speed is less than the low critical speed ω 0, if the current speed ω is less than the low critical speed ω 0, the fast speed reduction algorithm is started, and the first current value I max The second coefficient for representing the speed is calculated k 2, the second coefficient k 2 is calculated ω 2= k 2× i max Until the second actual speed ω 2 is quickly reduced to zero, then the current frequency control algorithm is executed to start the molecular pump, and after the second actual speed ω 2 reaches the low critical speed ω 0, the sliding mode observation algorithm is switched to estimate the speed ω obs and position θ obs of the molecular pump motor in real time, and continuously runs to the rated speed; if the current speed ω is greater than the low critical speed ω 0, the current back electromotive force data is read and the current speed and rotor position are calculated, and then the sliding mode observation algorithm is switched to estimate the speed ω obs and position θ obs of the molecular pump motor in real time, and continuously runs to the rated speed.

[0062] S103, when the control instruction is a shutdown instruction, obtaining a current rotating speed of the molecular pump, and executing a fast rotating speed reduction algorithm and a sliding mode observation algorithm according to a size relationship between the current rotating speed and a second rotating speed condition, so as to reduce the rotating speed of the molecular pump to zero; wherein the second rotating speed condition includes three conditions of a preset rotating speed before shutdown, a low critical rotating speed and zero rotating speed.

[0063] Specifically, referring to the right part of the flowchart in FIG. 1, a control process when the control instruction is a shutdown instruction is shown, and the control process is as follows. Figure 2

[0064] When the current rotating speed is less than the preset rotating speed before shutdown and less than the low critical rotating speed, the fast rotating speed reduction algorithm is started, a first current value when the fast rotating speed reduction algorithm is started is collected, and a fourth coefficient for representing the rotating speed is obtained according to a ratio of the current rotating speed to the first current value.

[0065] A second current value in the process of starting the fast rotating speed reduction algorithm is collected, and a fourth actual rotating speed satisfying the target rotating speed and the low critical rotating speed is obtained according to a product of the second current value and the fourth coefficient.

[0066] When the fourth actual rotating speed is zero, the shutdown control of the molecular pump is ended.

[0067] When the current rotating speed is greater than or equal to the preset rotating speed before shutdown, the fast rotating speed reduction algorithm is started, the first current value when the fast rotating speed reduction algorithm is started is collected, and a third coefficient for representing the rotating speed is obtained according to a ratio of the current rotating speed to the first current value; wherein the third coefficient is greater than the fourth coefficient.

[0068] The second current value in the process of starting the fast rotating speed reduction algorithm is collected, and a third actual rotating speed satisfying the target rotating speed is obtained according to a product of the second current value and the third coefficient, and the third actual rotating speed is taken as the current rotating speed when the shutdown instruction is received.

[0069] When the current rotating speed is greater than or equal to the low critical rotating speed, the back electromotive force data at the current time is read, the motor rotating speed and the rotor position of the molecular pump at the current time are calculated according to the back electromotive force data, and the current rotating speed is reduced to the low critical rotating speed.

[0070] In combination with the control process above, the full speed domain control process of the shutdown instruction is described in detail by taking the molecular pump in FIG. 1 as an example. Figure 2 When the shutdown instruction is received, if it is a shutdown instruction, the current rotating speed ω is obtained first, and it is determined whether the current rotating speed ω is less than the preset rotating speed before shutdown ω set1 If the current rotating speed ω is greater than the preset rotating speed before shutdown ω set1 ​Enable the fast deceleration algorithm and adjust it according to the first current value. I max The third coefficient that can be used to characterize rotational speed is calculated. k 3. Based on the third coefficient k 3. Calculate the current third actual speed. ω 3= k 3× i max The current third actual speed ω 3. Quickly reduce to the set speed ω set1 Then it will naturally decelerate; if the current speed is... ω Less than the speed set before shutdown ω set1 Then determine whether the current speed is lower than the lower critical speed. ω 0, if the current speed ω Less than the low critical speed ω 0, enable the fast deceleration algorithm, and adjust according to the first current value. I max A fourth coefficient that can be used to characterize rotational speed was calculated. k 4. According to the fourth coefficient k 4. Calculate the current fourth time rotation speed ω 4= k 4× i max The current fourth time rotation speed ω 4. Quickly reduce to zero; if the current speed ω greater than the low critical speed ω 0, Read the current back EMF data and calculate the current speed and rotor position for natural speed reduction.

[0071] The following practical application example illustrates the technical effects of this invention: In a molecular pump drive control project, the full-speed-range operation control method of this invention is used to drive and control a molecular pump with a rated speed of 90,000 rpm. The low critical speed is set at 3,000 rpm.

[0072] Using the method of this invention, the molecular pump is started in a static state, such as... Figure 3 As shown, upon receiving the startup command, the process...

[0073] If the current speed of the subpump is below the lower critical speed of 3000 rpm, the second actual speed is calculated based on the execution conditions. At this time, the current speed of the molecular pump is zero, and the molecular pump is started under current frequency control. When the speed is too high below the lower critical speed of 3000 rpm, the sliding mode observation algorithm is switched to drive the pump to the rated speed of 90000 rpm. The start-up process is smooth and reliable. Figure 3As shown, when receiving a stop command when running at a speed of 90000 rpm, natural speed reduction is performed since the target speed before stopping is 90000 rpm, and when the natural speed reduction reaches the low critical speed of 3000 rpm, the fast speed reduction algorithm is started, as shown in Figure 3 As shown, the speed of the molecular pump is quickly reduced to zero, and the process of stopping the speed reduction is stable and reliable, and the full range of speed values can be displayed.

[0074] By using the method of the present application, the molecular pump is started below the low critical speed of 3000 rpm, as shown in Figure 4 As shown, when starting from a stationary state to about 12500 rpm, a stop command is sent, the molecular pump is naturally reduced in speed, and when the natural speed reduction reaches the low critical speed of 3000 rpm, the fast speed reduction algorithm is started, and the speed of the molecular pump is reduced, as shown in Figure 4 As shown, when a start command is sent at about 800 rpm, the speed of the molecular pump is lower than the low critical speed of 3000 rpm, the fast speed reduction algorithm is continuously started, and when the speed is reduced to zero, the molecular pump is started, at this time the current speed of the molecular pump is zero, the current frequency control is started, and when the speed is lower than the low critical speed of 3000 rpm, the sliding mode observation algorithm is switched to drive to about 16000 rpm, a stop command is sent again, and the process of starting the molecular pump below the low critical speed of 3000 rpm is repeated, as shown in Figure 4 As shown, the molecular pump can be reliably started and stopped in the multiple start-stop processes, and the current speed value can be displayed.

[0075] As shown, the current speed value can be displayed.

[0076] By using the method of the present application, the molecular pump is started above the low critical speed of 3000 rpm, as shown in Figure 5 As shown, after starting the molecular pump from a stationary state to about 1000 rpm, a stop command is sent, the molecular pump is naturally reduced in speed, a start command is sent again, the molecular pump is quickly started, and this repeated test is performed multiple times, the molecular pump is started to the rated speed of 90000 rpm, after the test is completed, a stop command is sent, and the molecular pump is reduced to zero speed, and the whole process is stable and reliable.

[0077] By using the method of the present application, reliable operation control of the molecular pump in the whole speed range during starting and stopping can be realized, the molecular pump is successfully started 100% in the whole speed range, the full range of speed can be displayed during starting and stopping of the molecular pump, and smooth transition between starting and stopping can be realized.

[0078] The control method provided by the application has been verified on about 200 molecular pumps of the same type, and the start success rate reaches 100%, which shows high reliability. Compared with the traditional full-speed range operation control method, the full-speed range operation control method of the application has obvious advantages: the success rate at any speed in the rated speed range of the molecular pump reaches 100%, the full-speed range speed detection output during the start and stop process of the molecular pump can be realized, and no additional high-frequency noise and vibration is introduced. These improvements significantly improve the reliability of the full-speed range operation control of the molecular pump, and provide an effective solution for the optimization of the full-speed range operation control of the molecular pump.

[0079] The embodiment of the application also provides a control device applied to a molecular pump. The control device comprises a processor, a memory, a communication interface and at least one communication bus for connecting the processor, the memory and the communication interface. The memory comprises but is not limited to a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (PROM) or a portable compact disc read-only memory (CD-ROM), and is used for storing related instructions and data.

[0080] The communication interface is used for receiving and sending data. The processor can be one or more CPUs, and in the case of one CPU, the CPU can be a single-core CPU or a multi-core CPU. The processor in the control device is used to read one or more programs stored in the memory, and perform the following operations: receiving a control instruction and determining whether the control instruction is a start instruction or a shutdown instruction; when the control instruction is the start instruction, acquiring the current speed of the molecular pump, and executing a fast speed reduction algorithm, a sliding mode observation algorithm and a current frequency control algorithm according to the size relationship between the current speed and a first speed condition, so as to make the molecular pump run to the rated speed; wherein the first speed condition comprises three conditions of a target speed, a low critical speed and a speed of zero; when the control instruction is the shutdown instruction, acquiring the current speed of the molecular pump, and executing the fast speed reduction algorithm and the sliding mode observation algorithm according to the size relationship between the current speed and a second speed condition, so as to make the speed of the molecular pump reduce to zero; wherein the second speed condition comprises three conditions of a preset speed before shutdown, a low critical speed and a speed of zero.

[0081] It should be noted that the specific implementation of each operation can be described in the above Figure 1 The control device can be used to execute a molecular pump full-speed range operation control method of the above-mentioned method embodiments of the application, and details are not repeated here.

[0082] The embodiment of the present application further provides a computer readable storage medium, which is a memory device in a computer device and is used for storing programs and data. It can be understood that the computer readable storage medium herein can include an internal storage medium in the computer device, and of course can include an extended storage medium supported by the computer device. The computer readable storage medium provides a storage space, which stores an operating system of the terminal. Furthermore, one or more instructions suitable for being loaded and executed by the processor are stored in the storage space, and the instructions can be one or more computer programs (including program codes). It should be noted that the computer readable storage medium herein can be a high-speed RAM memory or a non-volatile memory, for example, at least one disk memory. The one or more instructions stored in the computer readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the molecular pump full-speed domain operation control method in the above embodiment. It should be understood by those skilled in the art that the embodiment of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can adopt a computer program product implemented on one or more computer usable storage media (including but not limited to a disk memory, a CD-ROM, an optical memory, etc.) containing computer usable program codes.

[0083] The above detailed description is further used to explain the purpose, technical scheme and beneficial effects of the present application. It should be understood that the above detailed description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for controlling the full-speed-range operation of a molecular pump, characterized in that, The methods include: Upon receiving a control command, determine whether the control command is a start command or a stop command; When the control command is a start command, the current speed of the molecular pump is obtained. Based on the relationship between the current speed and the first speed condition, the rapid deceleration algorithm, sliding mode observation algorithm, and current frequency control algorithm are executed to make the molecular pump run to the target speed. The first speed condition includes three conditions: target speed, low critical speed, and zero speed. The steps to bring the molecular pump to the target speed are as follows: When the current speed is less than the target speed and less than the low critical speed, a rapid deceleration algorithm is activated. The first current value when the rapid deceleration algorithm is activated is collected. Based on the ratio of the current speed to the first current value, a second coefficient is obtained to characterize the speed. The second current value during the activation of the rapid deceleration algorithm is collected. Based on the product of the second current value and the second coefficient, the second actual speed that satisfies both the target speed and the low critical speed conditions is obtained. When the second actual speed is zero, the current frequency control algorithm is activated to start the molecular pump. When the operating speed of the molecular pump controlled by the current frequency control algorithm is greater than the low critical speed, the sliding mode observation algorithm is switched to estimate the motor speed and rotor position of the molecular pump in real time until the target speed is reached, at which point the start-up control of the molecular pump ends. When the current speed is greater than or equal to the target speed, the rapid deceleration algorithm is activated. The first current value when the rapid deceleration algorithm is activated is collected. The first coefficient used to characterize the speed is obtained based on the ratio of the current speed to the first current value. The first coefficient is greater than the second coefficient. The second current value is collected during the activation of the rapid deceleration algorithm. The first actual speed that meets the target speed is obtained based on the product of the second current value and the first coefficient. The first actual speed is used as the current speed when the start command is received. If the current rotational speed is less than the target rotational speed but greater than or equal to the low critical rotational speed, the back electromotive force data at the current moment is read; the motor speed and rotor position of the molecular pump at the current moment are calculated based on the back electromotive force data, and then the sliding mode observation algorithm is switched to estimate the electronic speed and rotor position of the molecular pump in real time, and the operation continues until the target rotational speed is reached; When the control command is a shutdown command, the current speed of the molecular pump is obtained. Based on the relationship between the current speed and the second speed condition, a fast deceleration algorithm and a sliding mode observation algorithm are executed to reduce the speed of the molecular pump to zero. The second speed condition includes three conditions: the speed preset before shutdown, the low critical speed, and the speed of zero.

2. The method for controlling the full-speed-range operation of a molecular pump according to claim 1, characterized in that, If the second actual speed is not zero, the rapid deceleration algorithm will continue to be executed until the second actual speed is reduced to zero. If the operating speed of the molecular pump controlled by the current frequency control algorithm is less than or equal to the low critical speed, the current frequency control algorithm will continue to be executed until the operating speed of the molecular pump controlled by the current frequency control algorithm is greater than the low critical speed.

3. The method for controlling the full-speed-range operation of a molecular pump according to claim 1, characterized in that, When the control command is a shutdown command, the current speed of the molecular pump is obtained. Based on the relationship between the current speed and the second speed condition, a rapid deceleration algorithm and a sliding mode observation algorithm are executed to reduce the speed of the molecular pump to zero, including: When the current speed is lower than the preset speed before shutdown and lower than the low critical speed, the rapid deceleration algorithm is activated, the first current value when the rapid deceleration algorithm is activated is collected, and the fourth coefficient used to characterize the speed is obtained based on the ratio of the current speed to the first current value. The second current value is collected during the process of starting the rapid deceleration algorithm. Based on the product of the second current value and the fourth coefficient, the fourth actual speed is obtained under the two speed conditions of satisfying the target speed and the low critical speed. When the fourth actual rotational speed is zero, the shutdown control of the molecular pump ends.

4. The method for controlling the full-speed-range operation of a molecular pump according to claim 3, characterized in that, Also includes: When the current speed is greater than or equal to the preset speed before shutdown, the rapid deceleration algorithm is activated, the first current value when the rapid deceleration algorithm is activated is collected, and the third coefficient used to characterize the speed is obtained based on the ratio of the current speed to the first current value; wherein, the third coefficient is greater than the fourth coefficient. The second current value is collected during the process of starting the rapid deceleration algorithm. Based on the product of the second current value and the third coefficient, the third actual speed that satisfies the target speed is obtained, and the third actual speed is used as the current speed when the stop command is received.

5. The method for controlling the full-speed-range operation of a molecular pump according to claim 3, characterized in that, Also includes: If the current speed is less than the preset speed before shutdown, but greater than or equal to the low critical speed, then read the back EMF data at the current moment. The motor speed and rotor position of the molecular pump at the current moment are calculated based on the back electromotive force data until the current speed is reduced to the lower critical speed.

6. A control device for a molecular pump, characterized in that, Including memory and processor; A memory for storing computer programs, the computer programs including program instructions; A processor is configured to execute the program instructions to cause the control device to perform the steps of a molecular pump full-speed-range operation control method as described in any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program that, when executed by one or more processors, implements a molecular pump full-speed-range operation control method as described in any one of claims 1 to 5.

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