Control method and apparatus for magnetic levitation compressor, electronic device and storage medium

Abstract

A control method and apparatus for a magnetic levitation compressor, an electronic device and a storage medium. The control method comprises: in response to shutdown of a magnetic levitation compressor, acquiring the rotating direction of a rotor; on the basis of the operating state of the magnetic levitation compressor and the rotating direction being the reverse direction, acquiring the rotating speed of the rotor; on the basis of the rotating speed being greater than a first threshold value and not greater than a second threshold value, acquiring a delayed levitation stop duration corresponding to the rotating speed of the rotor; on the basis of a rotation duration of the rotor reaching the delayed levitation stop duration, controlling the rotor to stop levitating; and, on the basis of the rotating speed being greater than the second threshold value, controlling a frequency converter to brake the magnetic levitation compressor. The control method does not need to use valve body members to prevent reverse rotation of rotors of magnetic levitation compressors, thus improving the control stability for magnetic levitation compressors and the operation reliability of magnetic levitation compressors.

Description

Control method, device, electronic device and storage medium for magnetic levitation compressor

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 14, 2024, with application number 202410293586.9 and application name “Control method, device, electronic device and storage medium for magnetic levitation compressor”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the technical field of compressors, and in particular to a control method, device, electronic equipment and storage medium for a magnetic levitation compressor. Background Art

[0003] Magnetic levitation compressors are widely used in air conditioning systems due to their zero mechanical loss, lack of lubrication requirements, low losses, and quiet operation. A magnetic levitation compressor consists of a magnetic bearing stator, rotor, displacement sensor, protective bearing, and bearing controller. During operation, a controlled current flows through the stator windings of the magnetic bearing to generate a levitation force, enabling the rotor to remain in stable levitation.

[0004] During the operation of the magnetic levitation compressor, the suspended rotor rotates at high speed, requiring the rotor to rotate in only one direction to ensure the unidirectional flow of the refrigerant. If the rotor reverses, it will affect the operating reliability of the magnetic levitation compressor and may damage key mechanical components such as the impeller.

[0005] In the related art, the rotor is prevented from reversing by adding anti-reversal solenoid valves, one-way valves and other valve body components to the magnetic levitation compressor. However, due to the high failure rate of anti-reversal solenoid valves, one-way valves and other valve body components, the success rate of preventing the rotor from reversing is not high enough, resulting in insufficient reliability of the reversal prevention effect. Summary of the Invention

[0006] In response to the technical problems in the related art that the success rate of using valve body components to prevent the rotor reversal of a magnetic levitation compressor is not high enough and the reversal prevention effect is not reliable enough, the main purpose of the present invention is to provide a control method, device, electronic equipment and storage medium for a magnetic levitation compressor, aiming to improve the success rate of preventing the rotor reversal of the magnetic levitation compressor and improve the reliability of the reversal prevention effect.

[0007] According to one aspect of an embodiment of the present application, a control method for a magnetic levitation compressor is provided, comprising:

[0008] In response to the magnetic levitation compressor being shut down, obtaining a rotation direction of a rotor of the magnetic levitation compressor;

[0009] According to the magnetic levitation compressor being in an operating state and the rotation direction being reverse, obtaining the rotation speed of the rotor;

[0010] According to the rotation speed being greater than a first threshold and not greater than a second threshold, obtaining a delayed floating time corresponding to the rotation speed of the rotor;

[0011] According to the duration of the rotor rotation reaching the delayed floating time, controlling the rotor to stop floating;

[0012] According to the rotation speed being greater than a second threshold, a frequency converter connected to the magnetic levitation compressor is controlled to brake the magnetic levitation compressor.

[0013] In some embodiments of the present application, obtaining the delayed floating time corresponding to the rotational speed of the rotor includes:

[0014] An inverse time algorithm is used to obtain the delayed floating time corresponding to the rotational speed of the rotor.

[0015] In some embodiments of the present application, obtaining the rotation direction of the rotor of the magnetic levitation compressor includes:

[0016] The position of a preset mark on the rotor is detected by a sensor to obtain a pulse signal, wherein the sensor is arranged on the stator of the magnetic levitation compressor;

[0017] It is determined whether the rotation direction of the rotor is reverse according to the pulse signal.

[0018] In some embodiments of the present application, detecting the position of a preset mark on the rotor by a sensor to obtain a pulse signal includes:

[0019] The position of the preset groove on the rotor is detected by a displacement sensor to obtain a pulse signal.

[0020] In some embodiments of the present application, controlling a frequency converter connected to the magnetic levitation compressor to brake the magnetic levitation compressor includes:

[0021] A frequency converter connected to the magnetic levitation compressor is controlled to sequentially perform blocking pulse width modulation braking and short-circuit braking on the magnetic levitation compressor.

[0022] In some embodiments of the present application, controlling the frequency converter connected to the magnetic levitation compressor to sequentially perform blocking pulse width modulation braking and short-circuit braking on the magnetic levitation compressor includes:

[0023] Controlling a frequency converter connected to the magnetic levitation compressor to perform pulse width modulation braking on the magnetic levitation compressor until a dead time is less than a first preset time length;

[0024] The short-circuit braking is performed until the execution time of the short-circuit braking reaches a second preset time.

[0025] In some embodiments of the present application, the method further comprises:

[0026] According to the fact that the magnetic levitation compressor is in a standby state and the rotation speed of the rotor is greater than 0, an abnormal prompt signal is issued to set the magnetic levitation compressor to a non-startup state.

[0027] According to another aspect of an embodiment of the present application, a control device for a magnetic levitation compressor is provided, comprising:

[0028] a rotation direction acquisition module, configured to acquire a rotation direction of a rotor of the magnetic levitation compressor in response to the magnetic levitation compressor being shut down;

[0029] a rotation speed acquisition module, configured to acquire the rotation speed of the rotor according to the magnetic levitation compressor being in an operating state and the rotation direction being reverse;

[0030] a delayed floating time acquisition module, configured to acquire a delayed floating time corresponding to the rotation speed of the rotor according to the rotation speed being greater than a first threshold and not greater than a second threshold;

[0031] A floating module, configured to control the rotor to stop floating according to the duration of the rotor rotation reaching the delayed floating duration;

[0032] The braking module is configured to control a frequency converter connected to the magnetic levitation compressor to brake the magnetic levitation compressor according to the rotation speed being greater than a second threshold.

[0033] According to another aspect of an embodiment of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the control method of the magnetic levitation compressor described in any embodiment of the present application.

[0034] According to another aspect of the embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored. The computer program is executed by a processor to implement the control method of the magnetic levitation compressor described in any embodiment of the present application.

[0035] In the technical solution of the embodiment of the present application, in response to the shutdown of the magnetic levitation compressor, the rotation direction of the rotor of the magnetic levitation compressor is obtained, and according to the fact that the magnetic levitation compressor is in an operating state and the rotation direction is reversed, the rotation speed of the rotor is obtained, and according to the fact that the rotation speed is greater than a first threshold value and not greater than a second threshold value, the delayed stop time corresponding to the rotation speed of the rotor is obtained, and according to the continuous rotation time of the rotor reaching the delayed stop time length, the rotor is controlled to stop floating, and according to the fact that the rotation speed is greater than the second threshold value, the frequency converter connected to the magnetic levitation compressor is controlled to brake the magnetic levitation compressor, without the need to use a valve body part. The invention discloses a component to prevent the magnetic levitation compressor rotor from reversing, thereby improving the success rate of preventing the magnetic levitation compressor rotor from reversing and improving the reliability of the reverse prevention effect, thereby improving the control stability of the magnetic levitation compressor and the operation reliability of the magnetic levitation compressor, and overcoming the following technical defects existing in the related art: by adding anti-reverse solenoid valves, one-way valves and other valve body components to prevent the magnetic levitation compressor from reversing at the moment of shutdown, due to the high failure rate of valve body components such as anti-reverse solenoid valves, one-way valves, etc., the success rate of preventing the magnetic levitation compressor from reversing at the moment of shutdown is not high enough, resulting in insufficient reliability of the reverse prevention effect.

[0036] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the embodiments of the present application, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0038] FIG1 is a flow chart of a control method for a magnetic levitation compressor according to an embodiment of the present application;

[0039] FIG2 is a flow chart of obtaining the rotation state of the rotor of the magnetic levitation compressor in one embodiment of the present application;

[0040] FIG3 is a schematic diagram illustrating the relative positional relationship among the displacement sensor, the rotor, and the preset groove in one embodiment of the present application;

[0041] FIG4 is a pulse signal waveform diagram when the rotation direction of the rotor is forward rotation in one embodiment of the present application;

[0042] FIG5 is a pulse signal waveform diagram when the rotation direction of the rotor is reverse in one embodiment of the present application;

[0043] FIG6 is a flow chart of a control method for a magnetic levitation compressor according to a specific example of the present application;

[0044] FIG7 is a structural block diagram of a control device for a magnetic levitation compressor according to an embodiment of the present application;

[0045] FIG8 is a block diagram of the structure of an electronic device according to an embodiment of the present application;

[0046] FIG9 is a schematic diagram of a computer-readable storage medium according to an embodiment of the present application.

[0047] Description of Figure Numbers:

[0048] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0051] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0052] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0053] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] The occurrence of rotor reversal in a magnetic levitation compressor will affect its operational stability. There is a high probability that a magnetic levitation compressor will experience rotor reversal at the moment of shutdown. For example, a magnetic levitation compressor is prone to rotor reversal under large pressure differential conditions. The large pressure differential condition of a magnetic levitation compressor generally refers to a situation in which the pressure difference between the inlet and outlet of the magnetic levitation compressor is large during operation. The maximum pressure differential condition of a magnetic levitation compressor refers to the maximum pressure differential condition generated when the liquid passes through the rotating components inside the magnetic levitation compressor during operation. In the design and operation of a magnetic levitation compressor, the maximum pressure differential condition is a very important parameter that directly affects the working efficiency and operational stability of the magnetic levitation compressor. The maximum pressure differential condition of a magnetic levitation compressor is generally determined by a variety of factors, including the design parameters of the compressor, the physical properties of the liquid, and operating conditions.

[0055] In the related art, the magnetic levitation compressor rotor is prevented from reversing by adding anti-reverse solenoid valves, one-way valves and other valve body components to the magnetic levitation compressor. However, due to the high failure rate of anti-reverse solenoid valves, one-way valves and other valve body components, the success rate of preventing the magnetic levitation compressor rotor from reversing is not high enough, resulting in insufficient reliability of the reversal prevention effect.

[0056] In response to technical problems existing in the related art, an embodiment of the present application provides a control method for a magnetic levitation compressor. In response to the magnetic levitation compressor being shut down, a rotation direction of a rotor of the magnetic levitation compressor is obtained. Based on the magnetic levitation compressor being in an operating state and the rotation direction being reverse, a rotor speed is obtained. Based on the speed being greater than a first threshold and not greater than a second threshold, a delayed suspension time corresponding to the rotor speed is obtained. Based on the duration of rotor rotation reaching the delayed suspension time, the rotor is controlled to be suspended. Based on the speed being greater than the second threshold, a frequency converter connected to the magnetic levitation compressor is controlled to brake the magnetic levitation compressor. No valve body component is required to prevent reverse rotation of the magnetic levitation compressor rotor, thereby improving the success rate of preventing reverse rotation of the magnetic levitation compressor rotor and the reliability of the reverse rotation prevention effect. This improves the control stability of the magnetic levitation compressor and the operational reliability of the magnetic levitation compressor. The method overcomes the following technical defects existing in the related art: by adding valve body components such as an anti-reverse solenoid valve and a one-way valve to the magnetic levitation compressor to prevent reverse rotation of the magnetic levitation compressor rotor, due to the high failure rate of valve body components such as the anti-reverse solenoid valve and the one-way valve, the success rate of preventing reverse rotation of the magnetic levitation compressor rotor is not high, resulting in insufficient reliability of the reverse rotation prevention effect.

[0057] In addition, due to the high prices of valve body components such as anti-reverse solenoid valves and one-way valves, the technical solution in the related art of preventing the magnetic levitation compressor rotor from reversing by adding anti-reverse solenoid valves, one-way valves and other valve body components to the magnetic levitation compressor increases the cost of the magnetic levitation compressor. The control method of the magnetic levitation compressor in the embodiment of the present application does not require the use of anti-reverse solenoid valves, one-way valves and other valve body components, thereby reducing the cost of the magnetic levitation compressor.

[0058] The following describes the control method, control device, electronic device, and computer-readable storage medium of the magnetic levitation compressor provided by the embodiments of the present application with reference to examples.

[0059] Referring to FIG1 , an embodiment of the present application provides a control method for a magnetic levitation compressor, which may include steps S10 to S50:

[0060] S10 . In response to the magnetic levitation compressor being shut down, obtaining a rotation direction of a rotor of the magnetic levitation compressor.

[0061] As shown in Figure 2, obtaining the rotation direction of the rotor of the magnetic levitation compressor may include steps S101 to S102: S101, detecting the position of a preset mark on the rotor through a sensor to obtain a pulse signal, and the sensor is set on the stator of the magnetic levitation compressor; S102, judging whether the rotation direction of the rotor is reversed according to the pulse signal.

[0062] For example, the predetermined mark on the rotor may be a predetermined groove on the rotor, and the sensor may be a displacement sensor. Detecting the position of the predetermined mark on the rotor by the sensor to obtain a pulse signal may include: detecting the position of the predetermined groove on the rotor by the displacement sensor to obtain a pulse signal.

[0063] Specifically, as shown in Figure 3, the displacement sensor 1 detects the position of the preset groove 3 on the rotor 2 to obtain a pulse signal. The displacement sensor 1 can be, for example, an eddy current sensor, an inductive sensor, or the like.

[0064] For example, the predetermined mark on the rotor may be, for example, a predetermined color label on the rotor, and the sensor may be, for example, a color sensor. The predetermined color label is attached to the rotor, and the color sensor detects a position of the predetermined color label. Detecting the position of the predetermined mark on the rotor by the sensor to obtain a pulse signal may include: detecting the position of the predetermined color label on the rotor by the color sensor to obtain a pulse signal.

[0065] In some embodiments, determining whether the rotation direction of the rotor is reversed according to the pulse signal may specifically include: obtaining a waveform of the pulse signal, and determining whether the rotation direction of the rotor is reversed according to the waveform.

[0066] Specifically, the rotation direction of the rotor can be determined as forward rotation based on the convex part of the signal when the sensor detects the preset mark in the pulse signal waveform; the rotation direction of the rotor can be determined as reverse rotation based on the concave part of the signal when the sensor detects the preset mark in the pulse signal waveform.

[0067] Referring to Figure 4, the pulse signal waveform when the rotor rotates in the forward direction is a diagram, and the signal when the sensor detects the preset mark is the raised part, wherein the duration T from moment T1 to moment T3 is one cycle of rotor rotation, the duration from moment T3 to moment T5 is also T, the duration t from moment T1 to moment T2 represents the duration when the sensor detects the preset mark, the duration from moment T3 to moment T4 and the duration from moment T5 to moment T6 are both t.

[0068] Referring to Figure 5, the pulse signal waveform when the rotation direction of the rotor is reversed, the signal when the sensor detects the preset mark is the concave part, wherein the duration T from moment T1 to moment T3 is one cycle of rotor rotation, the duration from moment T3 to moment T5 is also T, the duration t from moment T1 to moment T2 represents the duration when the sensor detects the preset mark, the duration from moment T3 to moment T4 and the duration from moment T5 to moment T6 are both t.

[0069] Figures 4 and 5 both show the pulse signal waveforms corresponding to a uniform rotor speed. It is understandable that the rotor speed may also be non-uniform. In the case of a non-uniform speed, the period corresponding to one revolution of the rotor varies, and each period is different.

[0070] If the pulse signal waveform is as shown in Figure 4, the rotor of the magnetic levitation compressor can be determined to be rotating in the forward direction. If the pulse signal waveform is as shown in Figure 5, the rotor of the magnetic levitation compressor can be determined to be rotating in the reverse direction. When the magnetic levitation compressor is shut down, if the rotor is detected to be rotating in the forward direction, the compressor can be shut down normally.

[0071] S20: According to the magnetic levitation compressor being in a running state and rotating in a reverse direction, obtain the rotation speed of the rotor.

[0072] The rotor's speed refers to the number of revolutions per minute (rpm) it makes. Calculating the rotor's speed based on a pulse signal can, for example, include: obtaining the pulse signal's period based on the pulse signal's waveform, where the period is the duration required for the rotor to complete one rotation; and calculating the number of revolutions per minute (RPM) based on the period, thereby obtaining the rotor's speed. If the rotor's reverse speed is uniform, then the duration of each period in the waveform is equal, and any period in the waveform can be selected to calculate the rotor's speed.

[0073] For example, if the rotor's reversal speed is non-uniform, multiple cycles can be selected from the waveform graph, an average cycle can be calculated, and the rotational speed can be calculated based on the average cycle. That is, the rotor rotational speed is the average of the rotational speeds calculated based on the multiple cycles. For example, five consecutive cycles can be selected from the waveform graph. Assuming that the durations of the five cycles are 0.1s, 0.15s, 0.12s, 0.18s, and 0.2s, respectively, then the average duration of the five cycles is 0.15s. The rotational speed calculated based on the average cycle is 400 rpm, and 400 rpm is used as the rotor rotational speed.

[0074] In other examples, if the reversal speed of the rotor is non-uniform, the shortest period may be selected from a plurality of consecutive periods in the waveform graph, and the rotor speed may be calculated based on the shortest period, i.e., the rotor speed may be the maximum speed among the plurality of consecutive periods. For example, five consecutive periods may be selected from the waveform graph, and assuming that the durations of the five periods are 0.1s, 0.15s, 0.12s, 0.18s, and 0.2s, respectively, then the shortest duration of the five periods is 0.1s, and the speed calculated based on the shortest period is 600 rpm. The calculated speed of 600 rpm is used as the rotor speed.

[0075] When the inverter stops supplying power, the rotor speed gradually decreases, so the pulse signal period gradually increases. This allows us to calculate the duration of each period based on the pulse signal waveform, and from this period, the rotor speed, giving us the real-time speed corresponding to each period.

[0076] S30: Obtaining a delayed floating time corresponding to the rotation speed of the rotor based on the rotation speed being greater than the first threshold and not greater than the second threshold.

[0077] The first threshold and the second threshold are speed thresholds pre-set according to actual application needs, and the first threshold is less than the second threshold. Obtaining the delayed floating time corresponding to the rotor speed may include: using an inverse time algorithm to obtain the delayed floating time corresponding to the rotor speed.

[0078] The inverse time algorithm is used for overcurrent protection in power system protection. It determines the timing of protective action based on the magnitude and duration of the fault current. In this example, the delay tripping time is the protective action time. The inverse time algorithm sets a series of time curves based on different combinations of fault current levels and fault durations. These time curves are generally inverse, meaning that higher fault currents result in shorter protective action times, and vice versa.

[0079] For higher-level faults that result in larger fault currents, the protection device will execute protection actions based on the time obtained by the inverse time algorithm to quickly isolate the fault. For lower-level faults, the fault current is smaller, and the inverse time algorithm will provide a longer delay time to avoid false operations.

[0080] It is understandable that the time limit setting of the inverse time algorithm needs to be adjusted according to the specific application scenario characteristics and protection requirements. The reasonable time limit setting obtained by the inverse time algorithm can improve the reliability and sensitivity of the magnetic levitation compressor and prevent false operation and protection leakage.

[0081] S40: Control the rotor to stop floating according to the duration of the rotor rotation reaching the delayed stop floating duration.

[0082] The duration of the rotor rotation is timed, and when the duration of the rotor rotation reaches the aforementioned delayed suspension time, the rotor is controlled to stop suspending.

[0083] When the rotor is powered off, it continues to rotate due to inertia. Because the rotor is a permanent magnet, the relative motion between its magnetic field and the stator coils generates a braking torque that reduces the rotor's speed. Simultaneously, the relative motion between the rotor's magnetic field and the stator coils generates electrical energy that is stored in the inverter's bus capacitors. This converts the rotor's kinetic energy into electrical energy that is also stored in the inverter's bus capacitors.

[0084] "Floating" means ending the suspended state. Controlling the rotor to float also means ending the suspended state. In a magnetic levitation compressor, magnetic bearings utilize magnetic forces to levitate the rotor. The rotor's weight is supported by magnetic forces, and there is no mechanical contact between the suspended rotor and the stator. Controlling the rotor to float can include deactivating power to the magnetic bearings, thereby eliminating their magnetic force and freeing the rotor from magnetic support. This allows the rotor to end its suspended state and land on the stator.

[0085] When the rotor remains in the magnetic levitation compressor's shutdown state for the duration of the delayed suspension, the rotor's speed decreases to a preset speed. The preset speed is a relatively slow rotational speed at which the frictional damage caused by contact between the rotor and stator is within an acceptable range. Therefore, the rotor's suspension state can be terminated. This eliminates the need to wait for the rotor's speed to completely drop to zero before terminating the suspension state, shortening the time from when the inverter stops powering the magnetic levitation compressor to when the rotor stops floating, thereby improving operational efficiency.

[0086] For example, assuming that the inverse time algorithm calculates that the delayed floating time corresponding to the rotor speed is 1.2s, the timing starts from when the inverter stops supplying power. When the accumulated timing reaches 1.2s, the rotor can be controlled to float.

[0087] In addition, when the rotor is in a state of no power supply for a duration that reaches the delayed floating time, the rotor is controlled to stop floating. It is only necessary to start timing from the time when the inverter stops supplying power to the magnetic levitation compressor, and determine whether the rotor can be controlled to stop floating based on the accumulated timing time. There is no need to detect the rotor speed, and there is no need to determine whether the rotor can be controlled to stop floating based on the rotor speed. This operation process is relatively simple and saves the cost required to detect the rotor speed.

[0088] S50 : Controlling a frequency converter connected to the magnetic levitation compressor to brake the magnetic levitation compressor according to the rotation speed being greater than a second threshold value.

[0089] Illustratively, controlling the frequency converter connected to the magnetic levitation compressor to brake the magnetic levitation compressor may include: controlling the frequency converter connected to the magnetic levitation compressor to sequentially perform blocking pulse width modulation braking and short-circuit braking on the magnetic levitation compressor.

[0090] Exemplarily, controlling the frequency converter connected to the magnetic levitation compressor to sequentially perform blocking pulse width modulation braking and short-circuit braking on the magnetic levitation compressor may include: controlling the frequency converter connected to the magnetic levitation compressor to perform blocking pulse width modulation braking on the magnetic levitation compressor until the dead time is less than a first preset duration; and performing short-circuit braking until the short-circuit braking execution duration reaches a second preset duration.

[0091] Blocked pulse width modulation (PWM) is a pulse width modulation technology. In blocked pulse width modulation, the output voltage is expressed as the sum of space vectors. By calculating and controlling the timing and amplitude of these space vectors, precise control of the inverter can be achieved, improving system efficiency and reducing harmonic distortion. Compared with traditional pulse width modulation (PWM) technology, blocked pulse width modulation has the advantages of higher voltage utilization, lower harmonic distortion, and smaller electromagnetic interference. During the blocked pulse width modulation braking process, the output voltage and frequency of the magnetic levitation compressor can be adjusted by blocking pulse width modulation to achieve the desired braking effect. Blocked pulse width modulation braking achieves precise braking of the magnetic levitation compressor by precisely controlling the space vector, thereby improving braking efficiency.

[0092] Short-circuit braking creates a braking torque by introducing a short-circuit path between the motor windings, quickly slowing or stopping the motor. During short-circuit braking, the motor's power supply is disconnected, and the motor windings are directly connected together to create a short circuit. This generates a large current when the motor is running. This current creates a strong magnetic field in the motor windings, generating a braking torque. Short-circuit braking utilizes the motor's back EMF and resistance to generate a braking torque, rapidly slowing the motor and stopping it.

[0093] In some embodiments, the control method of the magnetic levitation compressor may further include: according to the magnetic levitation compressor being in a standby state and the rotation speed being greater than 0, issuing an abnormal prompt signal and setting the magnetic levitation compressor to a non-startup state.

[0094] When the magnetic levitation compressor is in standby mode, the rotor should be stationary under normal circumstances. If the speed is greater than 0 in the standby mode, it means that there is an abnormal condition in the magnetic levitation compressor, and an abnormal prompt signal is issued.

[0095] Exemplarily, the sending of an abnormal prompt signal may be to send an abnormal prompt message to the host computer of the magnetic levitation compressor or the terminal device of the relevant personnel (the terminal device may be, for example, a mobile phone, a personal computer, etc.), for example, to send a reminder text message to the mobile phone of the relevant personnel, so as to remind the relevant personnel to pay attention to the abnormal condition so that corresponding treatment measures can be taken in time. Exemplarily, the abnormal prompt signal may also be, for example, an audible and visual alarm signal, which may remind the relevant personnel to pay attention to the abnormal condition so that corresponding treatment measures can be taken in time. At the same time, setting the magnetic levitation compressor to a non-startup state may be, for example, to send an instruction so that the magnetic levitation compressor does not respond to any start-up instruction under the abnormal condition, thereby maintaining a non-startup state under the abnormal condition, so as to avoid the magnetic levitation compressor being started under the abnormal condition and causing damage to the magnetic levitation compressor.

[0096] In some examples, the control method may further include: according to the magnetic levitation compressor being in an operating state and rotating in a forward direction, controlling the magnetic levitation compressor to shut down in a conventional shutdown mode when shutdown is required.

[0097] It should be understood that the operating conditions of the magnetic levitation compressor to which the control method of the magnetic levitation compressor of the embodiment of the present application is applicable are not limited to the conditions of sudden shutdown due to large pressure difference during operation. As long as the conditions can produce rotor reversal, the control method of the embodiment of the present application is applicable.

[0098] Referring to Figure 6, a control method for a magnetic levitation compressor in a specific example obtains the rotation direction of the rotor of the magnetic levitation compressor at the moment the magnetic levitation compressor stops, and determines whether the rotation direction is reversed. If not, the magnetic levitation compressor is controlled to stop normally; if it is reversed, the reverse speed is obtained.

[0099] If the reverse speed exceeds the first threshold but not the second, an inverse-time algorithm is used to calculate the delayed suspension duration. Once the rotor rotation duration reaches the delayed suspension duration, the rotor is controlled to cease suspension. If the reverse speed exceeds the second threshold, the inverter connected to the magnetic levitation compressor is controlled to perform pulse-width modulation braking on the magnetic levitation compressor. Short-circuit braking is then applied until the deadband time is less than the first preset duration. Generator shutdown mode is then exited when the short-circuit braking duration reaches the second preset duration. If the reverse speed does not exceed the first threshold, generator shutdown mode is exited immediately.

[0100] Referring to FIG7 , another embodiment of the present application provides a control device for a magnetic levitation compressor, which may include:

[0101] a rotation direction acquisition module, configured to acquire a rotation direction of a rotor of the magnetic levitation compressor in response to the magnetic levitation compressor being shut down;

[0102] A speed acquisition module is used to acquire the speed of the rotor according to the magnetic levitation compressor being in a running state and the rotation direction being reverse;

[0103] A delayed floating time acquisition module is used to acquire a delayed floating time corresponding to the rotation speed of the rotor according to the rotation speed being greater than a first threshold and not greater than a second threshold;

[0104] A floating module is used to control the rotor to stop floating according to the duration of the rotor rotation reaching the delayed floating time;

[0105] The braking module is used to control the frequency converter connected to the magnetic levitation compressor to brake the magnetic levitation compressor according to the rotation speed being greater than the second threshold.

[0106] Exemplarily, the delayed floating time acquisition module is further specifically configured to acquire the delayed floating time corresponding to the rotational speed of the rotor by using an inverse time algorithm.

[0107] Exemplarily, the rotation direction acquisition module includes:

[0108] A pulse signal detection unit is used to detect the position of a preset mark on the rotor through a sensor to obtain a pulse signal, and the sensor is set on the stator of the magnetic levitation compressor;

[0109] The rotation direction judgment unit is used to judge whether the rotation direction of the rotor is reverse according to the pulse signal.

[0110] Exemplarily, the pulse signal detection unit is further specifically configured to detect the position of a preset groove on the rotor through a displacement sensor to obtain a pulse signal.

[0111] Exemplarily, the braking module is further specifically configured to control a frequency converter connected to the magnetic levitation compressor to sequentially perform pulse width modulation braking and short-circuit braking on the magnetic levitation compressor.

[0112] Exemplarily, the braking module is further specifically configured to:

[0113] Controlling a frequency converter connected to the magnetic levitation compressor to perform pulse width modulation braking on the magnetic levitation compressor until a dead time is less than a first preset time length;

[0114] The short-circuit braking is performed until the execution time of the short-circuit braking reaches a second preset time.

[0115] In some embodiments, the control device further includes a prompt module, which is configured to send an abnormal prompt signal according to the magnetic levitation compressor being in a standby state and the rotation speed of the rotor being greater than 0, and set the magnetic levitation compressor to a non-startup state.

[0116] Another embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in any one of the above embodiments.

[0117] As shown in reference Figure 8, the electronic device 10 may include: a processor 100, a memory 101, a bus 102 and a communication interface 103, and the processor 100, the communication interface 103 and the memory 101 are connected through the bus 102; the memory 101 stores a computer program that can be run on the processor 100, and when the processor 100 runs the computer program, it executes the method provided in any of the aforementioned embodiments of the present application.

[0118] The memory 101 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage. The communication connection between the device network element and at least one other network element is achieved through at least one communication interface 103 (which may be wired or wireless), and may use the Internet, a wide area network, a local area network, a metropolitan area network, etc.

[0119] Bus 102 may be an ISA bus, a PCI bus, or an EISA bus. Buses may be classified as address buses, data buses, and control buses. Memory 101 is used to store programs, and processor 100 executes the programs upon receiving execution instructions. The methods disclosed in any of the aforementioned embodiments of the present application may be applied to or implemented by processor 100.

[0120] The processor 100 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by hardware integrated logic circuits in the processor 100 or by software instructions. The above processor 100 may be a general-purpose processor, which may include a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of this application can be implemented or executed. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of this application can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory 101 , and the processor 100 reads the information in the memory 101 and completes the steps of the above method in combination with its hardware.

[0121] The electronic device provided in the embodiments of the present application and the method provided in the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the methods adopted, operated or implemented by them.

[0122] Another embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the method described in any of the above embodiments. Referring to FIG9 , the computer-readable storage medium shown is an optical disc 20 having a computer program (i.e., a program product) stored thereon. When executed by a processor, the computer program performs the method described in any of the above embodiments.

[0123] It should be noted that examples of computer-readable storage media may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0124] The computer-readable storage medium provided in the above-mentioned embodiments of the present application and the method provided in the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0125] It should be noted that the term "module" is not intended to be limited to a specific physical form. Depending on the specific application, a module can be implemented as hardware, firmware, software, and / or a combination thereof. Furthermore, different modules can share common components or even be implemented by the same components. There may or may not be clear boundaries between different modules.

[0126] The algorithm and display provided herein are not inherently related to any particular computer, virtual device or other equipment. Various general-purpose devices can also be used together with examples based on this. According to the above description, it is obvious that the structure required for constructing this type of device. In addition, the application is not directed to any specific programming language yet. It should be understood that various programming languages ​​can be utilized to realize the content of the application described herein, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the application.

[0127] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the flowcharts of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0128] The above embodiments merely represent implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A control method for a magnetic levitation compressor, characterized in that: include: In response to the magnetic levitation compressor being shut down, obtaining a rotation direction of a rotor of the magnetic levitation compressor; According to the magnetic levitation compressor being in an operating state and the rotation direction being reverse, obtaining the rotation speed of the rotor; According to the rotation speed being greater than a first threshold and not greater than a second threshold, obtaining a delayed floating time corresponding to the rotation speed of the rotor; According to the duration of the rotor rotation reaching the delayed floating time, controlling the rotor to stop floating; According to the rotation speed being greater than a second threshold, a frequency converter connected to the magnetic levitation compressor is controlled to brake the magnetic levitation compressor.

2. The method according to claim 1, wherein The obtaining of the delayed floating time corresponding to the rotational speed of the rotor includes: An inverse time algorithm is used to obtain the delayed floating time corresponding to the rotational speed of the rotor.

3. The method according to claim 1, wherein The obtaining of the rotation direction of the rotor of the magnetic levitation compressor includes: The position of a preset mark on the rotor is detected by a sensor to obtain a pulse signal, wherein the sensor is arranged on the stator of the magnetic levitation compressor; It is determined whether the rotation direction of the rotor is reverse according to the pulse signal.

4. The method according to claim 3, wherein The step of detecting the position of a preset mark on the rotor by a sensor to obtain a pulse signal includes: The position of the preset groove on the rotor is detected by a displacement sensor to obtain a pulse signal.

5. The method according to claim 1, wherein The step of controlling a frequency converter connected to the magnetic levitation compressor to brake the magnetic levitation compressor includes: A frequency converter connected to the magnetic levitation compressor is controlled to sequentially perform blocking pulse width modulation braking and short-circuit braking on the magnetic levitation compressor.

6. The method according to claim 5, wherein The control of the frequency converter connected to the magnetic levitation compressor sequentially performing pulse width modulation braking and short-circuit braking on the magnetic levitation compressor includes: Controlling a frequency converter connected to the magnetic levitation compressor to perform pulse width modulation braking on the magnetic levitation compressor until a dead time is less than a first preset time length; The short-circuit braking is performed until the execution time of the short-circuit braking reaches a second preset time.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: According to the fact that the magnetic levitation compressor is in a standby state and the rotation speed of the rotor is greater than 0, an abnormal prompt signal is issued to set the magnetic levitation compressor to a non-startup state.

8. A control device for a magnetic levitation compressor, characterized in that: include: a rotation direction acquisition module, configured to acquire a rotation direction of a rotor of the magnetic levitation compressor in response to the magnetic levitation compressor being shut down; a rotation speed acquisition module, configured to acquire the rotation speed of the rotor according to the magnetic levitation compressor being in an operating state and the rotation direction being reverse; a delayed floating time acquisition module, configured to acquire a delayed floating time corresponding to the rotation speed of the rotor according to the rotation speed being greater than a first threshold and not greater than a second threshold; A floating module, configured to control the rotor to stop floating according to the duration of the rotor rotation reaching the delayed floating duration; The braking module is configured to control a frequency converter connected to the magnetic levitation compressor to brake the magnetic levitation compressor according to the rotation speed being greater than a second threshold.

9. An electronic device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the control method of the magnetic levitation compressor according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the control method of the magnetic levitation compressor according to any one of claims 1 to 7.

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