A variable frequency drive apparatus and a variable frequency control method for improving resonance overhang

Abstract

The application discloses a variable frequency driving device and variable frequency control method and device for improving resonance superamplitude, and the method comprises the following steps: setting a carrier band set and a single operation cycle variable frequency strategy; setting a carrier set according to the carrier band set; detecting the resonance superamplitude of a small tube assembly through a vibration detection module to obtain a to-be-processed resonance superamplitude frequency range set; performing overlapping area merging processing on the to-be-processed resonance superamplitude frequency range set to obtain a target resonance superamplitude frequency range set; selecting one resonance superamplitude frequency range from the target resonance superamplitude frequency range set as a target resonance superamplitude frequency range; performing first carrier frequency adjustment processing to obtain a first variable frequency control result; if the first variable frequency control result is that resonance superamplitude still exists, performing second carrier frequency adjustment processing to obtain a second variable frequency control result. The application realizes variable frequency control, improves variable frequency stability, and reduces cost. The application can be applied to the technical field of motor control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, and in particular to a variable frequency driving device and a variable frequency control method and device for improving resonance amplitude. BACKGROUND

[0002] In an existing variable frequency driving air conditioning unit, the small pipe assembly connected with the compressor often has a problem of frequency band resonance. If the amplitude of the resonance position exceeds a certain test standard, the vibration of the small pipe assembly will cause periodic repeated deformation at some connection positions, leading to fatigue damage of the mechanical structure, and further causing leakage of refrigerant and refrigeration oil. The traditional method changes the resonance point by replacing the type, material, pipe path, shape, angle or counterweight of the small pipe assembly, but the cost of replacing the component structure is high. When the small pipe assembly structure cannot be replaced, the resonance amplitude is avoided by skipping the frequency band, but the setting of the frequency band affects the load linear regulation, and the variable frequency stability is low.

[0003] In summary, the technical problems in the related art need to be improved. SUMMARY

[0004] The present application provides a variable frequency driving device and a variable frequency control method and device for improving resonance amplitude, effectively improving variable frequency stability and reducing cost.

[0005] In one aspect, the present application provides a variable frequency driving device for improving resonance amplitude, comprising:

[0006] A vibration sensing module is installed on the small pipe assembly of the water chiller with a system component as a spacing, and the vibration sensing module is used to detect the vibration amplitude.

[0007] A vibration transmitting module is connected with the vibration sensing module, and the vibration transmitting module is used to convert the vibration amplitude into an analog signal.

[0008] A variable frequency module is used to adjust the operating frequency value.

[0009] A vibration detecting module is connected with the vibration transmitting module and the variable frequency module, and the vibration detecting module is used to make resonance amplitude judgment according to the operating frequency value and the analog signal, and obtain a resonance amplitude judgment result.

[0010] In some embodiments, the vibration sensing module is connected with the vibration transmitting module through a sensor line.

[0011] The present application has the following beneficial effects:

[0012] The embodiment of the present application provides a variable frequency driving device for improving resonance superamplitude, which comprises a vibration sensing module, a vibration transmitting module, a variable frequency module and a vibration detecting module. The vibration sensing module is installed on a small pipe assembly of a water chiller with a system component as a spacing, and is used for detecting a vibration amplitude; the vibration transmitting module is connected with the vibration sensing module, and is used for converting the vibration amplitude into an analog signal; the variable frequency module is used for adjusting a running frequency value; the vibration transmitting module and the variable frequency module are both connected with the vibration detecting module, the vibration detecting module is used for judging resonance superamplitude according to the running frequency value and the analog signal, and a resonance superamplitude judgment result is obtained, so that the variable frequency driving device is realized, the variable frequency stability is improved, and the cost is reduced.

[0013] In another aspect, the embodiment of the present application provides a variable frequency control method applied to the variable frequency driving device, which comprises the following steps:

[0014] Setting a carrier band set and a single running cycle variable frequency strategy;

[0015] According to the carrier band set, a carrier set is set, the carrier set comprises a first carrier frequency value, a second carrier frequency value and a third carrier frequency value, the first carrier frequency value is less than the second carrier frequency value, and the second carrier frequency value is less than the third carrier frequency value;

[0016] According to the single running cycle variable frequency strategy, resonance superamplitude detection is performed on the small pipe assembly by the vibration detecting module, and a to-be-processed resonance superamplitude frequency range set is obtained;

[0017] The to-be-processed resonance superamplitude frequency range set is subjected to overlapping region merging processing, and a target resonance superamplitude frequency range set is obtained;

[0018] One resonance superamplitude frequency range is selected from the target resonance superamplitude frequency range set as a target resonance superamplitude frequency range;

[0019] According to the first carrier frequency value, the second carrier frequency value and the target resonance superamplitude frequency range, first carrier frequency adjustment processing is performed, and a first variable frequency control result is obtained;

[0020] If the first variable frequency control result is that resonance superamplitude still exists, then according to the first carrier frequency value, the third carrier frequency value and the target resonance superamplitude frequency range, second carrier frequency adjustment processing is performed, and a second variable frequency control result is obtained.

[0021] In some embodiments, the execution process of the single running cycle variable frequency strategy comprises:

[0022] The running frequency value of the variable frequency module is set to 0;

[0023] adjusting the operating frequency value from 0 to a frequency maximum value according to a controller frequency ramping rate;

[0024] adjusting the operating frequency value from the frequency maximum value to 0 according to the controller frequency ramping rate.

[0025] In some embodiments, the setting the carrier band set comprises:

[0026] generating a first carrier band according to a first boundary carrier value and a second boundary carrier value, the first boundary carrier value being less than the second boundary carrier value;

[0027] generating a second carrier band according to the second boundary carrier value and a third boundary carrier value, the second boundary carrier value being less than the third boundary carrier value;

[0028] generating a third carrier band according to the third boundary carrier value and a fourth boundary carrier value, the third boundary carrier value being less than the fourth boundary carrier value;

[0029] combining the first carrier band, the second carrier band and the third carrier band to obtain the carrier band set.

[0030] In some embodiments, the setting the carrier set according to the carrier band set comprises:

[0031] taking a middle value of the first carrier band as the first carrier frequency value;

[0032] taking a middle value of the second carrier band as the second carrier frequency value;

[0033] taking a middle value of the third carrier band as the third carrier frequency value;

[0034] combining the first carrier frequency value, the second carrier frequency value and the third carrier frequency value to obtain the carrier set.

[0035] In some embodiments, the performing overlap region merging processing on the to-be-processed resonance over-amplitude frequency range set to obtain a target resonance over-amplitude frequency range set comprises:

[0036] selecting two resonance over-amplitude frequency ranges from the to-be-processed resonance over-amplitude frequency range set;

[0037] if the two resonance over-amplitude frequency ranges have a frequency overlap region, merging the two resonance over-amplitude frequency ranges to obtain the target resonance over-amplitude frequency range set.

[0038] In some embodiments, the first carrier frequency adjustment processing is performed according to the first carrier frequency value, the second carrier frequency value and the target resonance ultrasonic frequency range, and a first variable frequency control result is obtained, including:

[0039] The carrier of the variable frequency module is set to the first carrier frequency value;

[0040] When the frequency value of the variable frequency module rises to the minimum value in the target resonance ultrasonic frequency range, the carrier of the variable frequency module is updated to the second carrier frequency value, so that the frequency value of the variable frequency module falls to a first falling frequency value, which is less than the minimum value in the target resonance ultrasonic frequency range;

[0041] According to the maximum value in the target resonance ultrasonic frequency range and a preset frequency difference, a target frequency value is calculated;

[0042] When the frequency value of the variable frequency module rises to the target frequency value, the carrier of the variable frequency module is updated to the first carrier frequency value;

[0043] According to the first judgment result of the vibration detection module, the first variable frequency control result is generated.

[0044] In some embodiments, the second carrier frequency adjustment processing is performed according to the first carrier frequency value, the third carrier frequency value and the target resonance ultrasonic frequency range, and a second variable frequency control result is obtained, including:

[0045] The carrier of the variable frequency module is set to the first carrier frequency value;

[0046] When the frequency value of the variable frequency module rises to the minimum value in the target resonance ultrasonic frequency range, the carrier of the variable frequency module is updated to the third carrier frequency value, so that the frequency value of the variable frequency module falls to a second falling frequency value, which is less than the minimum value in the target resonance ultrasonic frequency range;

[0047] When the frequency value of the variable frequency module rises to the target frequency value, the carrier of the variable frequency module is updated to the first carrier frequency value;

[0048] According to the second judgment result of the vibration detection module, the second variable frequency control result is generated.

[0049] In another aspect, the embodiments of the present application provide a variable frequency control device, including:

[0050] The first module is used for setting a carrier band set and a single operation cycle variable frequency strategy;

[0051] The second module is configured to set a carrier set according to the carrier band set, the carrier set including a first carrier frequency value, a second carrier frequency value and a third carrier frequency value, the first carrier frequency value being less than the second carrier frequency value, and the second carrier frequency value being less than the third carrier frequency value.

[0052] The third module is configured to perform resonance amplitude detection on the small tube assembly by the vibration detection module according to the single operation cycle frequency conversion strategy, to obtain a set of to-be-processed resonance amplitude frequency ranges.

[0053] The fourth module is configured to perform overlapping region merging processing on the set of to-be-processed resonance amplitude frequency ranges, to obtain a set of target resonance amplitude frequency ranges.

[0054] The fifth module is configured to select one resonance amplitude frequency range from the set of target resonance amplitude frequency ranges as a target resonance amplitude frequency range.

[0055] The sixth module is configured to perform first carrier frequency adjustment processing according to the first carrier frequency value, the second carrier frequency value and the target resonance amplitude frequency range, to obtain a first frequency conversion control result.

[0056] The seventh module is configured to, if the first frequency conversion control result is that resonance amplitude still exists, perform second carrier frequency adjustment processing according to the first carrier frequency value, the third carrier frequency value and the target resonance amplitude frequency range, to obtain a second frequency conversion control result.

[0057] The present application has the following beneficial effects:

[0058] The embodiment of the present application first sets a carrier band set and a single operation cycle frequency conversion strategy, sets a carrier set according to the carrier band set, then performs resonance amplitude detection on the small tube assembly by the vibration detection module according to the single operation cycle frequency conversion strategy, to obtain a set of to-be-processed resonance amplitude frequency ranges, performs overlapping region merging processing on the set of to-be-processed resonance amplitude frequency ranges, to obtain a set of target resonance amplitude frequency ranges, selects one resonance amplitude frequency range from the set of target resonance amplitude frequency ranges as a target resonance amplitude frequency range, finally performs first carrier frequency adjustment processing according to the first carrier frequency value, the second carrier frequency value and the target resonance amplitude frequency range, to obtain a first frequency conversion control result, and if the first frequency conversion control result is that resonance amplitude still exists, performs second carrier frequency adjustment processing according to the first carrier frequency value, the third carrier frequency value and the target resonance amplitude frequency range, to obtain a second frequency conversion control result, so that frequency conversion control is realized, frequency conversion stability is improved, and cost is reduced.

[0059] Additional features and advantages of the present application will be set forth in the description that follows, and in part will be apparent from the description, or can be learned by practice of the present application. The objectives and other advantages of the present application will be realized and attained by the structure particularly pointed out in the description and appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

[0061] Figure 1 A schematic view of a centrifugal compressor and a refrigerant and refrigeration oil pipeline assembly connected thereto according to an embodiment of the present application;

[0062] Figure 2 A structural schematic view of a variable frequency driving device for improving resonance super-amplitude according to an embodiment of the present application;

[0063] Figure 3 A flow chart of a variable frequency control method according to an embodiment of the present application;

[0064] Figure 4 A schematic view of an overall flow of a carrier adaptive adjustment of a frequency converter according to an embodiment of the present application;

[0065] Figure 5 A structural schematic view of a variable frequency control device according to an embodiment of the present application. DETAILED DESCRIPTION

[0066] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementation described in the following exemplary embodiments does not represent all the implementations consistent with the embodiments of the present application, but is only an example of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0067] It can be understood that the terms "first", "second" and the like used in the present application can be used herein to describe various concepts, but unless specifically stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiments of the present application, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information. Depending on the context, the word "if" as used herein can be interpreted as "when" or "upon determination" or "in response to determining".

[0068] The terms "at least one", "multiple", "each", "any" and the like used in the present application include one, two or more than two, multiple includes two or more than two, each refers to each of the corresponding plurality, and any refers to any one of the plurality.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application, and are not intended to limit the present application.

[0070] Before the embodiments of the present application are described in detail, first, some nouns and terms involved in the embodiments of the present application are described, and the nouns and terms involved in the embodiments of the present application are applicable to the following explanations.

[0071] Resonance amplitude: refers to the amplitude of the resonance position in a plurality of small pipe assemblies connected to the compressor, which exceeds the test standard when in a certain frequency range.

[0072] In the related art, the existing variable frequency driven air conditioning unit, such as a centrifugal / screw water chiller, often has resonance in some frequency bands of the compressor in some small pipe assemblies connected to the compressor. If the amplitude of these resonance positions is large, exceeding a certain test standard, the whole machine will be judged as unqualified. Because of the vibration of the small pipe assembly, periodic repeated deformation will occur at some connection positions, which will cause fatigue damage of the mechanical structure over a long period of time, and then cause leakage of refrigerant and refrigeration oil. The current industry processing method is mainly to process such problems through structure, including: (1) replacing the type of small pipe assembly, increasing the inner diameter of the small pipe, thereby reducing the flow rate in the pipe and the resonance frequency point; (2) replacing the material of the small pipe, such as replacing the copper pipe with a stainless steel pipe, thereby changing the resonance position of this section of the small pipe; (3) changing the pipe path and shape of the small pipe, angle, thereby changing the resonance point; (4) adding a counterweight to the small pipe assembly, or adding a shock pad to change the resonance point of the pipe. In addition, in the case where the small pipe assembly resonance cannot be avoided, the industry generally avoids it by skipping the frequency band, such as: detecting that the frequency range in the "40-45Hz" frequency band resonates seriously, and setting the corresponding frequency band in the variable frequency converter preset program. When the variable frequency converter is in the process of increasing or decreasing the frequency, it will quickly pass through this frequency band, reducing the time of resonance. But the initial intention of using a variable frequency unit in general projects is to smoothly adjust the cooling capacity under different cooling capacity requirements. Frequent "frequency band skipping" will destroy the stable output of the variable frequency unit refrigeration capacity, causing frequent fluctuations in the entire refrigeration system. As for the identification of the frequency skipping range, it is generally judged by setting a patch on the main pipe to test the "vibration amplitude" and setting an "acceleration sensor" to see if it meets the relevant standards. That is, the test personnel need to record the data feedback by the test instrument to determine whether it exceeds the vibration amplitude and record the "frequency skipping range" to be set.

[0073] The current several traditional shock absorption measures are to change the structure to change the resonance point of the pipe to improve the influence of resonance. The disadvantages of the traditional shock absorption method are as follows: (1) increased cost, whether changing the existing structure scheme or adding new counterweights, etc. will increase the manufacturing and testing cost of the whole machine; (2) from the perspective of the deterioration factors "generation->transmission->impact", the above methods only act on "reducing the impact", and "avoiding the impact" does not solve the vibration problem at the source; (3) according to the actual test data of each unit compared with the vibration related national standard, and then manually set the frequency skipping range to improve the vibration state of the small pipe assembly. But too many frequency skipping ranges will lose the significance of using variable frequency technology to realize linear load regulation.

[0074] Therefore, the embodiment of the present application adopts dynamic adjustment of the carrier (fc) frequency of the variable frequency driver according to the resonance over-amplitude frequency range, thereby weakening the resonance over-amplitude of the small pipe assembly, improving the variable frequency stability, and reducing the cost.

[0075] The embodiments of the present application will be explained in detail below with reference to the drawings:

[0076] In some embodiments, the refrigerant and refrigeration oil pipeline assembly is taken as the detection target, and an example of the refrigerant and refrigeration oil pipeline assembly connected with the centrifugal compressor is shown in FIG. 1. Figure 1 As shown in FIG. 1, the compressor is composed of a front guide vane regulating valve M1, a compressor body (primary and secondary impellers), and a rear driving motor. The suction port of the compressor is connected with the evaporator of the water chiller air conditioner, and the exhaust port of the compressor is connected with the condenser of the water chiller air conditioner. The remaining parts are small pipe assemblies connected to the compressor. According to the legend, the pipe with the filling pattern is the refrigerant pipe, and the pipe without the filling pattern is the oil pipe. There are four small pipe assemblies in the figure, which are defined as small pipe assembly A, small pipe assembly B, small pipe assembly C, and small pipe assembly D. Among them, the small pipe assemblies A and B are refrigerant small pipes, and the small pipe assemblies C and D are oil pipes. The refrigerant small pipe assembly mainly cools the centrifugal refrigeration oil and the main motor through the condenser, including: the refrigerant small pipe assembly A passes through the filter A, the plate heat exchanger of the oil cooler, and then passes through the refrigerant to take away the heat of the refrigeration oil, and then passes through the refrigerant adjusting valve M2 to return to the evaporator; the refrigerant small pipe assembly B passes through the filter B and is connected to the main motor to cool the compressor motor. The oil pipe assembly mainly collects the refrigeration lubricating oil from the rear end of the secondary impeller of the compressor, passes through the oil pump, and then returns to the compressor through two groups of small pipes, including: the oil pipe assembly C passes through the oil cooler from the oil pump and passes through the adjusting valve M3, and then passes through the oil filter to the middle part of the compressor; the oil pipe assembly D passes through the oil dryer from the oil pump and is sent to the Venturi tube position at the secondary impeller, and the oil connected to the evaporator return oil pipe is mixed and sent back to the secondary impeller of the compressor by the injection method. When the variable frequency motor drives the compressor to operate, the vibration (resonance) amplitude exceeds the limit mainly occurs at some position points of the four types of small pipe assemblies. At different operating frequencies, the resonance position may occur at different one or several positions.

[0077] In some embodiments, as shown in FIG. 2, the embodiment of the present application provides a variable frequency driving device for improving the resonance over-amplitude, which comprises: Figure 2

[0078] The vibration sensing module 201 is installed on the small pipe assembly of the water chiller set at an interval of a system component, and is used for detecting the vibration amplitude.

[0079] ​a vibration transmitting module 202 connected with the vibration sensing module, configured to convert the vibration amplitude into an analog signal;

[0080] a frequency conversion module 203 configured to adjust a running frequency value;

[0081] a vibration detecting module 204 connected with the vibration transmitting module and the frequency conversion module, configured to make a resonance amplitude exceeding judgment according to the running frequency value and the analog signal, to obtain a resonance amplitude exceeding judgment result.

[0082] In some embodiments, the present application provides a frequency conversion driving device for improving resonance amplitude exceeding, which comprises a vibration sensing module 201, a vibration transmitting module 202, a frequency conversion module 203 and a vibration detecting module 204. The vibration sensing module is installed on a small pipe assembly of a water chiller at intervals of a system component, and is configured to detect vibration amplitude. For example, the vibration sensing module can comprise vibration sensors, which can be arranged on the small pipe assembly where resonance amplitude exceeding is likely to occur, and the vibration sensors can be arranged according to actual needs, for example, one vibration sensor can be arranged on a pipe at an interval of one system component. The vibration transmitting module is connected with the vibration sensing module, and is configured to convert the vibration amplitude into an analog signal. In some embodiments, the vibration sensing module 201 is connected with the vibration transmitting module 202 through a sensor line. For example, the vibration transmitting module can comprise a vibration transmitter, the vibration transmitter is connected with the vibration sensor through the sensor line, the vibration transmitter can convert the vibration amplitude into an analog signal of 0V-10V or 4mA-20mA, and the sensor line can comprise AIn and COM. The frequency conversion module is configured to adjust a running frequency value, and can comprise a frequency converter. The vibration transmitting module and the frequency conversion module are both connected with the vibration detecting module, and the vibration detecting module (controller) is configured to make a resonance amplitude exceeding judgment according to the running frequency value and the analog signal, to obtain a resonance amplitude exceeding judgment result. For example, the vibration transmitter is connected with the vibration detecting module 204 through the sensor line, and the vibration detecting module 204 is connected with the frequency converter through a communication line. The vibration detecting module reads the running frequency value of the frequency converter in real time through the communication when the frequency converter is running, controls the frequency converter to gradually increase or decrease the frequency during the test, reads the vibration value fed back by each vibration sensor, compares the vibration value with a preset vibration limit value, to determine whether resonance amplitude exceeding occurs, and obtains a resonance amplitude exceeding judgment result.

[0083] In some embodiments, the conventional centrifugal compressor variable frequency driver generally uses a fixed carrier wave, which is set before the variable frequency driver is operated and cannot be adjusted during operation. However, the carrier wave in the present embodiment can be automatically adjusted during operation. The carrier wave frequency (fc) is generally set in three frequency ranges: (1) 1 kHz-4 kHz; (2) 4 kHz-8 kHz; and (3) 8 kHz-16 kHz. The conventional variable frequency driver selects one value from each of the three carrier wave frequency ranges as the default configuration.

[0084] In some embodiments, the higher the carrier wave frequency, the smaller the torque fluctuation of the variable frequency driver output, that is, the more stable the motor operation, and the smaller the vibration impact on the small tube assembly. However, the higher the carrier wave frequency, the more negative impact on the motor and operating circuit: first, the switching loss caused by the frequent switching of the variable frequency driver; second, the motor will bear a higher voltage change rate (du / dt). In a high-power motor, the motor winding distributed capacitance is large, and the high du / dt will make the motor winding bear a higher voltage profit, which is easy to cause motor insulation aging in long-term operation; third, high-frequency carrier wave will cause electromagnetic interference (EMI) to increase. Therefore, considering the stable operation and energy saving of the system, the default carrier wave frequency of the variable frequency driver is generally set to be low.

[0085] The beneficial effects of implementing the present embodiment include that the present embodiment provides a variable frequency drive device for improving resonance overshoot, which includes a vibration sensing module, a vibration transmitting module, a variable frequency module, and a vibration detection module. The vibration sensing module is installed on the small tube assembly of the water chiller with a system component as a spacer, for detecting the vibration amplitude; the vibration transmitting module is connected with the vibration sensing module, for converting the vibration amplitude into an analog signal; the variable frequency module is used for adjusting the operating frequency value; the vibration transmitting module and the variable frequency module are both connected with the vibration detection module, and the vibration detection module is used for judging the resonance overshoot according to the operating frequency value and the analog signal, to obtain the resonance overshoot judgment result, thereby realizing the variable frequency drive device, improving the variable frequency stability, and reducing the cost.

[0086] The variable frequency control method provided by the embodiments of the present application relates to the technical field of motor control. The variable frequency control method provided by the embodiments of the present application can be applied to a terminal, can be applied to a server, and can also be software running in the terminal or the server. In some embodiments, the terminal can be a smart phone, a tablet computer, a notebook computer, a desktop computer, a smart speaker, a smart watch, a vehicle-mounted terminal, and the like, but is not limited thereto. The server end can be configured as a stand-alone physical server, can be configured as a server cluster or a distributed system formed by multiple physical servers, can be configured as a cloud server providing basic cloud computing services such as cloud service, cloud database, cloud computing, cloud function, cloud storage, network service, cloud communication, middleware service, domain name service, security service, CDN, and big data and artificial intelligence platform, and the server can also be a node server in a blockchain network. The software can be an application that implements a variable frequency control method, and the like, but is not limited to the above forms.

[0087] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, multi-processor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and the like. The present application can be described in the general context of computer-executable instructions executed by a computer, such as a program module. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The present application can also be practiced in a distributed computing environment in which tasks are performed by remote processing devices connected by a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media, including storage devices.

[0088] Figure 3 is an optional flowchart of a variable frequency control method applied to a variable frequency driving device provided by the embodiments of the present application, Figure 3 The method in the above table can include, but is not limited to, steps S301 to S307.

[0089] Step S301, setting a carrier band set and a single operation period variable frequency strategy;

[0090] Step S302, setting a carrier set according to the carrier band set, the carrier set including a first carrier frequency value, a second carrier frequency value, and a third carrier frequency value, the first carrier frequency value being less than the second carrier frequency value, and the second carrier frequency value being less than the third carrier frequency value;

[0091] In step S303, according to the single operation cycle frequency conversion strategy, the vibration detection module is used to detect the resonance amplitude of the small tube assembly, and a set of resonance amplitude frequency ranges to be processed is obtained.

[0092] In step S304, the set of resonance amplitude frequency ranges to be processed is subjected to overlapping region merging processing, and a set of target resonance amplitude frequency ranges is obtained.

[0093] In step S305, one resonance amplitude frequency range is selected from the set of target resonance amplitude frequency ranges as a target resonance amplitude frequency range.

[0094] In step S306, according to the first carrier frequency value, the second carrier frequency value and the target resonance amplitude frequency range, first carrier frequency adjustment processing is performed, and a first frequency conversion control result is obtained.

[0095] In step S307, if the first frequency conversion control result is that there is still resonance amplitude, according to the first carrier frequency value, the third carrier frequency value and the target resonance amplitude frequency range, second carrier frequency adjustment processing is performed, and a second frequency conversion control result is obtained.

[0096] The steps S301 to S307 shown in the embodiments of the present application realize frequency conversion control, improve frequency conversion stability, and reduce cost.

[0097] In some embodiments, in step S301, setting a set of carrier bands can include but is not limited to the following steps:

[0098] According to the first boundary carrier value and the second boundary carrier value, a first carrier band is generated, and the first boundary carrier value is less than the second boundary carrier value.

[0099] According to the second boundary carrier value and the third boundary carrier value, a second carrier band is generated, and the second boundary carrier value is less than the third boundary carrier value.

[0100] According to the third boundary carrier value and the fourth boundary carrier value, a third carrier band is generated, and the third boundary carrier value is less than the fourth boundary carrier value.

[0101] The first carrier band, the second carrier band and the third carrier band are combined to obtain a set of carrier bands.

[0102] In some embodiments, a first carrier band can be generated according to a first boundary carrier value and a second boundary carrier value, where the first boundary carrier value is less than the second boundary carrier value. For example, the first boundary carrier value can be 1 kHz, the second boundary carrier value can be 4 kHz, and the first carrier band can be 1 kHz-4 kHz. Then a second carrier band can be generated according to the second boundary carrier value and a third boundary carrier value, where the second boundary carrier value is less than the third boundary carrier value; for example, the third boundary carrier value can be 8 kHz, and the second carrier band can be 4 kHz-8 kHz. Then a third carrier band can be generated according to the third boundary carrier value and a fourth boundary carrier value, where the third boundary carrier value is less than the fourth boundary carrier value; for example, the fourth boundary carrier value can be 16 kHz, and the third carrier band can be 8 kHz-16 kHz. Finally, the first carrier band, the second carrier band, and the third carrier band are combined to obtain a carrier band set.

[0103] In some embodiments, in step S301, the execution process of the single operation cycle frequency conversion strategy includes:

[0104] setting the running frequency value of the frequency conversion module to 0;

[0105] adjusting the running frequency value from 0 to the maximum frequency value according to the controller frequency up and down rate;

[0106] adjusting the running frequency value from the maximum frequency value to 0 according to the controller frequency up and down rate.

[0107] In some embodiments, the execution process of the single operation cycle frequency conversion strategy can first set the running frequency value of the frequency conversion module to 0, then adjust the running frequency value from 0 to the maximum frequency value according to the controller frequency up and down rate, and finally adjust the running frequency value from the maximum frequency value to 0 according to the controller frequency up and down rate. For example, in one operation cycle of the single operation cycle frequency conversion strategy, the frequency converter runs from the minimum frequency value fmin (i.e. 0 Hz) to the highest upper limit value fmax (i.e. the maximum frequency value), and then runs from the frequency upper limit value fmax to fmin (i.e. 0 Hz). By setting the controller frequency up and down rate (e.g. 1 Hz per second), whether each small tube assembly vibrates at each frequency value can be accurately fed back to the vibration detection module.

[0108] In some embodiments, in step S302, setting the carrier set according to the carrier band set can include but is not limited to the following steps:

[0109] taking the middle value of the first carrier band as the first carrier frequency value;

[0110] taking the middle value of the second carrier band as the second carrier frequency value;

[0111] taking the middle value of the third carrier band as the third carrier frequency value;

[0112] combining the first carrier frequency value, the second carrier frequency value and the third carrier frequency value to obtain a carrier set.

[0113] In some embodiments, the middle value of the first carrier band can be taken as the first carrier frequency value Fc1, 1kHz < Fc1 < 4kHz, the middle value of the second carrier band can be taken as the second carrier frequency value Fc2, 4kHz < Fc2 < 8kHz, and the middle value of the third carrier band can be taken as the third carrier frequency value Fc3, 8kHz < Fc3 < 16kHz. More specifically, the initial setting of the frequency converter carrier is Fc1, Fc1 < Fc2 < Fc3.

[0114] In some embodiments, in step S303, the vibration detection module can be used to detect the resonance amplitude of the small tube assembly according to the single operation cycle variable frequency strategy to obtain a set of to-be-processed resonance amplitude frequency ranges. For example, in the first operation cycle, the vibration detection module can be used to detect the resonance amplitude of the small tube assembly to confirm the frequency range of the vibration amplitude of each small tube assembly, and obtain a set of to-be-processed resonance amplitude frequency ranges.

[0115] In some embodiments, in step S304, the set of to-be-processed resonance amplitude frequency ranges can be merged according to the overlapping region to obtain a set of target resonance amplitude frequency ranges, which can include but is not limited to the following steps:

[0116] selecting two resonance amplitude frequency ranges from the set of to-be-processed resonance amplitude frequency ranges;

[0117] If the two resonance amplitude frequency ranges have a frequency overlap region, the two resonance amplitude frequency ranges are merged to obtain a set of target resonance amplitude frequency ranges.

[0118] In some embodiments, in the second operation cycle, repeated detection can be performed to confirm whether the resonance amplitude region phenomenon in the first operation cycle is consistent. After the detection is completed, the vibration detection module can mark the resonance region of each small tube assembly in the system, such as intervals 1, 2, …, n. When the frequency values of the resonance amplitude of the small tube assembly overlap, the set of to-be-processed resonance amplitude frequency ranges can be merged according to the overlapping region to obtain a set of target resonance amplitude frequency ranges. Two resonance amplitude frequency ranges can be selected from the set of to-be-processed resonance amplitude frequency ranges, and if the two resonance amplitude frequency ranges have a frequency overlap region, the two resonance amplitude frequency ranges can be merged in the resonance region standard to obtain a set of target resonance amplitude frequency ranges.

[0119] In some embodiments, in step S305, one resonant ultra-amplitude frequency range can be selected from the set of target resonant ultra-amplitude frequency ranges as a target resonant ultra-amplitude frequency range, so as to subsequently perform adaptive carrier frequency adjustment processing on the target resonant ultra-amplitude frequency range. More specifically, the same adaptive carrier frequency adjustment processing can be performed on each resonant ultra-amplitude frequency range in the set of target resonant ultra-amplitude frequency ranges to obtain a corresponding frequency conversion control result.

[0120] In some embodiments, in step S306, performing first carrier frequency adjustment processing according to the first carrier frequency value, the second carrier frequency value, and the target resonant ultra-amplitude frequency range to obtain the first frequency conversion control result can include but is not limited to the following steps:

[0121] setting the carrier of the frequency conversion module to the first carrier frequency value;

[0122] when the frequency value of the frequency conversion module rises to the minimum value in the target resonant ultra-amplitude frequency range, updating the carrier of the frequency conversion module to the second carrier frequency value, so that the frequency value of the frequency conversion module falls to a first falling frequency value, and the first falling frequency value is less than the minimum value in the target resonant ultra-amplitude frequency range;

[0123] calculating a target frequency value according to the maximum value in the target resonant ultra-amplitude frequency range and a preset frequency difference;

[0124] when the frequency value of the frequency conversion module rises to the target frequency value, updating the carrier of the frequency conversion module to the first carrier frequency value;

[0125] generating the first frequency conversion control result according to the first judgment result of the vibration detection module.

[0126] In some embodiments, in the third running cycle, the first carrier frequency adjustment processing is performed on the collected target resonance super-amplitude frequency range. The carrier frequency of the frequency conversion module can be set as a first carrier frequency value first, and when the frequency value of the frequency conversion module rises to the minimum value in the target resonance super-amplitude frequency range, the carrier frequency of the frequency conversion module is updated to a second carrier frequency value, so that the frequency value of the frequency conversion module falls to a first falling frequency value, wherein the first falling frequency value is less than the minimum value in the target resonance super-amplitude frequency range. For example, if it is identified in the first running cycle and the second running cycle that the resonance super-amplitude occurs at a position of the small tube assembly (A / B / C / D) in the frequency interval n (f1-f2), in the third running cycle, when the frequency converter operates at a frequency of f1 Hz, the carrier frequency of the frequency converter is switched from the first carrier frequency value Fc1 to the second carrier frequency value Fc2. In this short switching process, the frequency of the frequency converter will fall to a first falling frequency value f1'(f1'<f1). It can be understood that f1' is a value obtained by monitoring at all times, which is related to the operating state and characteristics of the motor. During the carrier frequency switching process, the motor will temporarily lose driving force, and the motor speed will decrease. The motor monitoring module in the driving device detects the motor operating frequency value in real time, and after the carrier frequency of the device is switched, the motor frequency needs to be continuously pulled up at a suitable frequency value. Then, according to the maximum value in the target resonance super-amplitude frequency range and a preset frequency difference, a target frequency value is calculated, wherein the calculation formula of the target frequency value is: f2'=f2-△f2, wherein f2' is the target frequency value, f2 is the maximum value in the target resonance super-amplitude frequency range, and △f2 is the preset frequency difference, and the range of △f2 can be set to 3-5 Hz, which can be set in the frequency converter parameters. When the frequency value of the frequency conversion module rises to the target frequency value, the carrier frequency of the frequency conversion module is updated to the first carrier frequency value, and finally, the first frequency conversion control result is generated according to the first judgment result of the vibration detection module. For example, the frequency converter that has completed the carrier switching will determine the motor operating position through the built-in algorithm observer, and the operating frequency value will be raised from f1' to f2'(f2'>f2) again. If no resonance super-amplitude occurs in this process, when the operating frequency value reaches f2', the carrier frequency of the frequency converter is adjusted back to Fc1, and the first frequency conversion control result is generated.

[0127] In some embodiments, in step S307, the second carrier frequency adjustment processing is performed according to the first carrier frequency value, the third carrier frequency value and the target resonance super-amplitude frequency range, and a second frequency conversion control result is obtained, which can include but is not limited to the following steps:

[0128] The carrier frequency of the frequency conversion module is set as the first carrier frequency value;

[0129] when the frequency value of the variable frequency module rises to the minimum value in the target resonance overhang frequency range, updating the carrier of the variable frequency module to a third carrier frequency value, so that the frequency value of the variable frequency module falls to a second falling frequency value, the second falling frequency value being less than the minimum value in the target resonance overhang frequency range;

[0130] when the frequency value of the variable frequency module rises to the target frequency value, updating the carrier of the variable frequency module to the first carrier frequency value;

[0131] According to the second judgment result of the vibration detection module, a second variable frequency control result is generated.

[0132] In some embodiments, in the fourth running cycle, if the target resonance overhang frequency range after the first carrier frequency adjustment processing still has a resonance overhang, the target resonance overhang frequency range is subjected to a second carrier frequency adjustment processing. The carrier of the variable frequency module can be first set to the first carrier frequency value, when the frequency value of the variable frequency module rises to the minimum value in the target resonance overhang frequency range, the carrier of the variable frequency module is updated to the third carrier frequency value, so that the frequency value of the variable frequency module falls to the second falling frequency value, the second falling frequency value being less than the minimum value in the target resonance overhang frequency range; when the frequency value of the variable frequency module rises to the target frequency value, the carrier of the variable frequency module is updated to the first carrier frequency value, and then a second variable frequency control result is generated according to the second judgment result of the vibration detection module. Exemplarily, if the target resonance overhang frequency range after the first carrier frequency adjustment processing still has a resonance overhang, i.e. the frequency interval n (f1-f2), in this running cycle, when the frequency converter runs to a frequency of f1 Hz, the carrier of the frequency converter is actively switched from the first carrier frequency value Fc1 to the third carrier frequency value Fc3. This short switching process will cause the frequency of the frequency converter to fall to a second falling frequency value f3'(f3' < f1), and the frequency converter with switched carrier will determine the motor running position through the built-in algorithm observer, and then rise from f3' to f4'(f4' > f2) again. If no resonance overhang occurs in this process, when the running frequency value reaches f4', the carrier of the frequency converter is adjusted back to the first carrier frequency value Fc1. It can be understood that the carriers switched by the first carrier frequency adjustment processing and the second carrier frequency adjustment processing are different, the first carrier frequency adjustment processing switches to the second carrier frequency value Fc2, and the second carrier frequency adjustment processing switches to the third carrier frequency value Fc3, Fc2 < Fc3.

[0133] In some embodiments, the controller judges the vibration state after completing the adaptive adjustment of four running cycles: (1) if there is no resonance amplitude overshoot in the first two cycles, the adaptive carrier adjustment function is not triggered; (2) in the third cycle, when the resonance amplitude overshoot is eliminated after the carrier is switched from Fc1 to Fc2, the system records the running data and writes the parameters into the frequency converter; if the problem cannot be solved, the next stage of adaptive carrier adjustment function is triggered; (3) in the fourth cycle, when the resonance amplitude overshoot is eliminated after the carrier is switched from Fc1 to Fc3, the system records the running data and writes the parameters into the frequency converter; if the problem cannot be solved, it proves that the problem cannot be solved by setting the carrier frequency alone. The system prompts the user to change the structure (such as increasing the thickness of the small tube, changing the material, or adding counterweight) and then repeat the adaptive adjustment. Further, after completing all test links, the resonance amplitude overshoot problem of the water chiller is effectively improved. At this time, the vibration test module has written the carrier frequency values corresponding to each frequency range into the frequency converter operating parameters. The test personnel can remove the variable frequency drive device on the small tube assembly and perform other test links. When all test contents are completed, the water chiller can be delivered to the customer for use.

[0134] In some embodiments, the overall process of adaptive adjustment of the frequency converter carrier is as shown in Figure 4 The first running cycle is executed according to the single running cycle variable frequency strategy to detect the frequency range of the resonance amplitude overshoot, and then the second running cycle is executed to confirm the resonance amplitude interval. If the resonance amplitude overshoot occurs, the third running cycle is executed to perform adaptive adjustment strategy 1, i.e., first carrier frequency adjustment processing, including adjusting the carrier from Fc1 to Fc2. If the resonance amplitude overshoot point is still not eliminated, the fourth running cycle is executed to perform adaptive adjustment strategy 2, i.e., second carrier frequency adjustment processing, including adjusting the carrier from Fc1 to Fc3. By comparing and selecting the appropriate adaptive adjustment strategy, if the resonance amplitude overshoot point is still not eliminated, the controller issues an instruction to prompt the customer to change the structure of the small tube assembly that causes the resonance amplitude overshoot; if the resonance amplitude overshoot point is eliminated, the controller of the variable frequency drive device writes the carrier frequency values at different running frequencies into the frequency converter, and removes the variable frequency drive device. After completing other parts of the test, it is delivered to the customer.

[0135] In some embodiments, the embodiment can improve the generation of motor vibration from the source of the frequency converter driving motor, without canceling the "frequency band skipping", but using the carrier position of the frequency converter to realize the smooth adjustment of the full frequency band. The embodiment uses an automatic measurement method to improve the resonance problem by automatically adjusting the operation strategy through the pre-set vibration judgment value and the algorithm inside the frequency converter. It can be extended to centrifugal machines, screw machines, modular machines and other refrigeration units; it can be applied to water pumps, air compressors, fans and other frequency conversion driving equipment. The device and method of the embodiment can be applied in the scenes of water pump pipeline resonance and fan air pipe resonance.

[0136] The beneficial effects of implementing the embodiment of the application include: the embodiment of the application first sets a carrier band set and a single running period variable frequency strategy, sets a carrier set according to the carrier band set, then detects resonance amplitude exceeding of a small pipe assembly through a vibration detection module according to the single running period variable frequency strategy to obtain a to-be-processed resonance amplitude exceeding frequency range set, performs overlapping region merging processing on the to-be-processed resonance amplitude exceeding frequency range set to obtain a target resonance amplitude exceeding frequency range set, selects a resonance amplitude exceeding frequency range from the target resonance amplitude exceeding frequency range set as a target resonance amplitude exceeding frequency range, and finally performs first carrier frequency adjustment processing according to the first carrier frequency value, the second carrier frequency value and the target resonance amplitude exceeding frequency range to obtain a first variable frequency control result, so that if the first variable frequency control result still exists resonance amplitude exceeding, performs second carrier frequency adjustment processing according to the first carrier frequency value, the third carrier frequency value and the target resonance amplitude exceeding frequency range to obtain a second variable frequency control result, thereby realizing variable frequency control, improving variable frequency stability and reducing cost.

[0137] As shown in Figure 5 the embodiment of the application further provides a variable frequency control device, which comprises:

[0138] The first module 801 is used for setting a carrier band set and a single running period variable frequency strategy.

[0139] The second module 802 is used for setting a carrier set according to the carrier band set, wherein the carrier set comprises a first carrier frequency value, a second carrier frequency value and a third carrier frequency value, the first carrier frequency value is less than the second carrier frequency value, and the second carrier frequency value is less than the third carrier frequency value.

[0140] The third module 803 is used for detecting resonance amplitude exceeding of a small pipe assembly through a vibration detection module according to the single running period variable frequency strategy to obtain a to-be-processed resonance amplitude exceeding frequency range set.

[0141] The fourth module 804 is used for performing overlapping region merging processing on the to-be-processed resonance amplitude exceeding frequency range set to obtain a target resonance amplitude exceeding frequency range set.

[0142] The fifth module 805 is configured to select one resonance over-amplitude frequency range from the set of target resonance over-amplitude frequency ranges as a target resonance over-amplitude frequency range.

[0143] The sixth module 806 is configured to perform first carrier frequency adjustment processing according to the first carrier frequency value, the second carrier frequency value, and the target resonance over-amplitude frequency range, to obtain a first frequency conversion control result.

[0144] The seventh module 807 is configured to, if the first frequency conversion control result is that resonance over-amplitude still exists, perform second carrier frequency adjustment processing according to the first carrier frequency value, a third carrier frequency value, and the target resonance over-amplitude frequency range, to obtain a second frequency conversion control result.

[0145] The content in the method embodiments is applicable to the device embodiments, the device embodiments specifically implement the same functions as the method embodiments, and achieve the same beneficial effects as the method embodiments.

[0146] The preferred embodiments of the application are described above with reference to the accompanying drawings, and the scope of the application is not limited by this. Any modification, equivalent replacement, and improvement made by those skilled in the art without departing from the scope and essence of the application should be within the scope of the application.

Claims

1. A variable frequency control method applied to a variable frequency drive device, characterized by, The variable frequency driving device comprises: A vibration sensing module is installed on the small tube assembly of the water chiller with a system component as a spacing, and is used for detecting a vibration amplitude; A vibration transmitting module is connected with the vibration sensing module, and is used for converting the vibration amplitude into an analog signal; A variable frequency module is used for adjusting a running frequency value; The vibration transmitting module and the variable frequency module are both connected with a vibration detecting module, and the vibration detecting module is used for judging resonance over amplitude according to the running frequency value and the analog signal, and obtaining a resonance over amplitude judgment result; The variable frequency control method comprises the following steps: Setting a carrier band set and a single running cycle variable frequency strategy; According to the carrier band set, a carrier set is set, the carrier set comprises a first carrier frequency value, a second carrier frequency value and a third carrier frequency value, the first carrier frequency value is less than the second carrier frequency value, and the second carrier frequency value is less than the third carrier frequency value; According to the single running cycle variable frequency strategy, the vibration detecting module is used for detecting resonance over amplitude of the small tube assembly, and a to-be-processed resonance over amplitude frequency range set is obtained; The to-be-processed resonance over amplitude frequency range set is subjected to overlapping region merging processing, and a target resonance over amplitude frequency range set is obtained; One resonance over amplitude frequency range is selected from the target resonance over amplitude frequency range set as a target resonance over amplitude frequency range; According to the first carrier frequency value, the second carrier frequency value and the target resonance over amplitude frequency range, first carrier frequency adjustment processing is performed, and a first variable frequency control result is obtained; If the first variable frequency control result is that resonance over amplitude still exists, according to the first carrier frequency value, the third carrier frequency value and the target resonance over amplitude frequency range, second carrier frequency adjustment processing is performed, and a second variable frequency control result is obtained; The execution process of the single running cycle variable frequency strategy comprises: The running frequency value of the variable frequency module is set to 0; According to a controller frequency lifting and lowering rate, the running frequency value is adjusted from 0 to a frequency maximum value; According to the controller frequency lifting and lowering rate, the running frequency value is adjusted from the frequency maximum value to 0.

2. The method of claim 1, wherein, The vibration sensing module is connected with the vibration transmitting module through a sensor line.

3. The method of claim 1, wherein, The carrier band set is set, comprising: A first carrier band is generated according to a first boundary carrier value and a second boundary carrier value, the first boundary carrier value is less than the second boundary carrier value; A second carrier band is generated according to the second boundary carrier value and a third boundary carrier value, the second boundary carrier value is less than the third boundary carrier value; A third carrier band is generated according to the third boundary carrier value and a fourth boundary carrier value, the third boundary carrier value is less than the fourth boundary carrier value; The first carrier band, the second carrier band and the third carrier band are combined to obtain the carrier band set.

4. The method of claim 3, wherein, According to the carrier band set, the carrier set is set, comprising: The middle value of the first carrier band is taken as the first carrier frequency value; taking the middle value of the second carrier band as the second carrier frequency value; taking the middle value of the third carrier band as the third carrier frequency value; combining the first carrier frequency value, the second carrier frequency value and the third carrier frequency value to obtain the carrier set.

5. The method of claim 1, wherein, The overlapping region merging processing of the to-be-processed resonance over-amplitude frequency range set to obtain a target resonance over-amplitude frequency range set comprises: selecting two resonance over-amplitude frequency ranges from the to-be-processed resonance over-amplitude frequency range set; if the two resonance over-amplitude frequency ranges have a frequency overlapping region, merging the two resonance over-amplitude frequency ranges to obtain the target resonance over-amplitude frequency range set.

6. The method of claim 1, wherein, The first carrier frequency adjustment processing according to the first carrier frequency value, the second carrier frequency value and the target resonance over-amplitude frequency range to obtain a first frequency conversion control result comprises: setting the carrier of the frequency conversion module to the first carrier frequency value; when the frequency value of the frequency conversion module rises to the minimum value in the target resonance over-amplitude frequency range, updating the carrier of the frequency conversion module to the second carrier frequency value, so that the frequency value of the frequency conversion module falls to a first falling frequency value, which is less than the minimum value in the target resonance over-amplitude frequency range; calculating a target frequency value according to the maximum value in the target resonance over-amplitude frequency range and a preset frequency difference; when the frequency value of the frequency conversion module rises to the target frequency value, updating the carrier of the frequency conversion module to the first carrier frequency value; generating the first frequency conversion control result according to the first judgment result of the vibration detection module.

7. The method of claim 6, wherein, The second carrier frequency adjustment processing according to the first carrier frequency value, the third carrier frequency value and the target resonance over-amplitude frequency range to obtain a second frequency conversion control result comprises: setting the carrier of the frequency conversion module to the first carrier frequency value; when the frequency value of the frequency conversion module rises to the minimum value in the target resonance over-amplitude frequency range, updating the carrier of the frequency conversion module to the third carrier frequency value, so that the frequency value of the frequency conversion module falls to a second falling frequency value, which is less than the minimum value in the target resonance over-amplitude frequency range; when the frequency value of the frequency conversion module rises to the target frequency value, updating the carrier of the frequency conversion module to the first carrier frequency value; generating the second frequency conversion control result according to the second judgment result of the vibration detection module.

8. A variable frequency control device, characterized by, comprises: The first module is used for setting a carrier band set and a single operation cycle frequency conversion strategy, and an execution process of the single operation cycle frequency conversion strategy comprises: setting an operation frequency value of a frequency conversion module to 0; adjusting the operation frequency value from 0 to a frequency maximum value according to a controller frequency raising and lowering rate; adjusting the operation frequency value from the frequency maximum value to 0 according to the controller frequency raising and lowering rate; The second module is configured to set a carrier set according to the carrier band set, the carrier set including a first carrier frequency value, a second carrier frequency value, and a third carrier frequency value, the first carrier frequency value being less than the second carrier frequency value, and the second carrier frequency value being less than the third carrier frequency value; The third module is configured to perform resonance amplitude detection on the small tube assembly through the vibration detection module according to the single operation cycle frequency conversion strategy, to obtain a set of to-be-processed resonance amplitude frequency ranges; The fourth module is configured to perform overlapping region merging processing on the set of to-be-processed resonance amplitude frequency ranges, to obtain a set of target resonance amplitude frequency ranges; The fifth module is configured to select one resonance amplitude frequency range from the set of target resonance amplitude frequency ranges as a target resonance amplitude frequency range; The sixth module is configured to perform first carrier frequency adjustment processing according to the first carrier frequency value, the second carrier frequency value, and the target resonance amplitude frequency range, to obtain a first frequency conversion control result; The seventh module is configured to perform second carrier frequency adjustment processing according to the first carrier frequency value, the third carrier frequency value, and the target resonance amplitude frequency range, to obtain a second frequency conversion control result, if the first frequency conversion control result is that resonance amplitude still exists.

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