Control method and device of motor rotor cooling system, medium and program product
By setting inner and outer spiral cooling channels in the magnetic levitation motor and using back electromotive force to calculate the rotor temperature, the problem of high temperature of the rotor in high-speed permanent magnet motors is solved, real-time adaptive control of rotor temperature is realized, permanent magnet demagnetization is prevented, and the operational reliability and efficiency of the unit are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-03-20
AI Technical Summary
The rotor of a high-speed permanent magnet motor is prone to high temperature under the action of high-frequency harmonics, which leads to demagnetization of the permanent magnet. Existing technology makes it difficult to effectively detect and control the rotor temperature.
Inner and outer spiral cooling channels are set on the outer circle of the stator of the magnetic levitation motor. The rotor temperature is calculated by obtaining the reference back EMF and the cooling system is controlled according to the temperature threshold, including adjusting the opening of the cooling channel and the carrier frequency of the frequency converter to regulate the rotor temperature.
It enables real-time detection and adaptive adjustment of rotor temperature, preventing demagnetization of permanent magnets and improving the operational reliability and efficiency of the unit.
Smart Images
Figure CN121704592A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of control, in particular to a control method, device, medium and program product of a motor rotor cooling system, and specifically designs a control method, device, medium and program product of a magnetic suspension motor rotor cooling system. BACKGROUND
[0002] The temperature rise of a motor is one of the important indicators for measuring the performance of the motor, which is directly related to the service life of the motor. If the temperature rise is too high, the motor is prone to damage. Especially for high-speed permanent magnet motors, due to their small size and high power density, high-frequency harmonics will generate large eddy current loss on the surface of the rotor core and the permanent magnet, causing the rotor to operate at a high temperature, which can easily cause the permanent magnet to demagnetize. Therefore, it is particularly important to detect the temperature of the motor rotor, especially the permanent magnet. SUMMARY
[0003] The main purpose of the present application is to overcome the defects of the above-mentioned related technology, and to provide a control method, device, medium and program product of a motor rotor cooling system to solve the problem of detecting the temperature of the motor rotor in the related technology.
[0004] In one aspect, the present application provides a control method of a magnetic suspension motor rotor cooling system. The cooling system includes an inner layer spiral cooling flow channel and an outer layer spiral cooling flow channel arranged on the outer circle of the stator of the magnetic suspension motor. After the cooling system is turned on, one of the inner layer spiral cooling flow channel and the outer layer spiral cooling flow channel is turned on, and the other is turned off. The control method includes obtaining the reference back electromotive force of the magnetic suspension motor and the temperature of the motor rotor of the magnetic suspension motor according to the reference back electromotive force. According to the obtained temperature of the motor rotor, the cooling system of the magnetic suspension motor rotor is controlled. When the temperature of the motor rotor is less than or equal to a first preset temperature threshold, the cooling system is controlled to maintain the current state. When the temperature of the motor rotor is greater than the first preset temperature threshold and less than a second preset temperature threshold, the opening degree of the control valve of the opened spiral cooling flow channel is increased. When the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, the carrier frequency of the frequency converter is increased and / or the other spiral cooling flow channel of the cooling system is turned on.
[0005] Optionally, according to the reference back electromotive force, the temperature of the motor rotor of the magnetic suspension motor is obtained, including: calculating the back electromotive force of the motor rotor of the magnetic suspension motor according to the current parameters of the magnetic suspension motor as the calculated back electromotive force, the parameters including: rotor electrical angle, stator winding number of turns and maximum magnetic flux; and calculating the temperature of the motor rotor according to the reference back electromotive force, the calculated back electromotive force and the indoor environment temperature.
[0006] Optionally, the temperature of the motor rotor is calculated according to the reference counter electromotive force, the calculated counter electromotive force and the indoor ambient temperature, and the temperature of the motor rotor is calculated according to the following formula: temperature of the motor rotor = (E1-E0) / E0*k+T 内环 ; wherein E0 is the calculated counter electromotive force, E1 is the detected counter electromotive force, T 内环 is the indoor ambient temperature, and k is a material temperature sensitivity coefficient.
[0007] Optionally, the method further comprises: when the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, issuing a prompt information.
[0008] In another aspect, the application provides a control device of a magnetic levitation motor rotor cooling system, the cooling system comprising: an inner layer spiral cooling flow channel and an outer layer spiral cooling flow channel arranged on an outer circle of a stator of the magnetic levitation motor, one of the inner layer spiral cooling flow channel and the outer layer spiral cooling flow channel being opened and the other being closed after the cooling system is turned on, the control device comprising: an acquisition unit configured to acquire a reference counter electromotive force of the magnetic levitation motor and a temperature of a motor rotor of the magnetic levitation motor according to the reference counter electromotive force; and a control unit configured to control the cooling system of the magnetic levitation motor rotor according to the temperature of the motor rotor acquired by the acquisition unit, wherein: when the temperature of the motor rotor is less than or equal to a first preset temperature threshold, the control unit controls the cooling system to maintain a current state; when the temperature of the motor rotor is greater than the first preset temperature threshold and less than a second preset temperature threshold, the control unit increases an opening degree of a control valve of the opened spiral cooling flow channel; and when the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, the control unit controls a frequency converter to increase a carrier frequency and / or controls the other spiral cooling flow channel of the cooling system to be opened.
[0009] Optionally, the acquisition unit acquires the temperature of the motor rotor of the magnetic levitation motor according to the reference counter electromotive force, and the method comprises: calculating a counter electromotive force of the motor rotor of the magnetic levitation motor according to current parameters of the magnetic levitation motor as a calculated counter electromotive force, the parameters comprising: a rotor electric angle, a stator winding number of turns and a maximum magnetic flux; and calculating the temperature of the motor rotor according to the reference counter electromotive force, the calculated counter electromotive force and the indoor ambient temperature.
[0010] Optionally, the temperature of the motor rotor is calculated according to the reference counter electromotive force, the calculated counter electromotive force and the indoor ambient temperature, and the temperature of the motor rotor is calculated according to the following formula: temperature of the motor rotor = (E1-E0) / E0*k+T 内环; wherein E0 is a calculated back EMF, E1 is a detected back EMF, T 内环 is the indoor ambient temperature, and k is the material temperature sensitivity coefficient.
[0011] Optionally, the method further comprises: prompting, when the temperature of the motor rotor is greater than or equal to a second preset temperature threshold, issuing a prompt information.
[0012] In still another aspect, the present application provides a storage medium having stored thereon a computer program, which, when executed by a processor, implements the steps of any of the preceding methods.
[0013] In yet another aspect, the present application provides a magnetic levitation motor controller, comprising a processor, a memory, and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of any of the preceding methods when executing the program.
[0014] In yet another aspect, the present application provides a magnetic levitation motor controller, comprising the control device of any of the preceding aspects.
[0015] In yet another aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of any of the preceding methods.
[0016] According to the technical solution of the present application, the rotor temperature is directly and real-timely calculated by the analytical method, the cooling system is controlled according to the rotor temperature, the rotor temperature regulation is realized, and when the rotor temperature exceeds the threshold value, the rotor temperature is reduced by the frequency converter to increase the carrier or to open a cooling flow channel until the rotor temperature meets the requirements, the cooling is adaptively adjusted according to the rotor temperature, the rotor temperature is real-timely controlled, and the unit operation is ensured; the self-adaptive adjustment of the rotor heat dissipation system is beneficial to improving the unit efficiency.
[0017] According to the technical solution of the present application, the rotor temperature can be real-timely detected, and the optimal heat dissipation scheme is adaptively matched according to the rotor temperature, thereby effectively preventing the irreversible demagnetization of the permanent magnet caused by the high temperature of the rotor under the adverse working conditions, and ensuring the reliable operation of the compressor and effectively improving the compressor efficiency. BRIEF DESCRIPTION OF DRAWINGS
[0018] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings: Figure 1 is a method schematic diagram of an embodiment of the control method of the magnetic levitation motor rotor cooling system provided by the present application; Figure 2 shows a structure schematic diagram of the magnetic levitation motor rotor cooling system; Figure 3is a method schematic view of a specific embodiment of the control method of the cooling system of the magnetic suspension motor rotor provided by the application; Figure 4 is a structure block diagram of an embodiment of the control device of the magnetic suspension motor rotor cooling system provided by the application. DETAILED DESCRIPTION
[0019] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in conjunction with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.
[0020] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to include only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.
[0021] The present application provides a control method of a magnetic suspension motor rotor cooling system. The magnetic suspension motor rotor cooling system comprises a motor, a frequency converter and a cooling system. The cooling system comprises an inner layer spiral cooling flow channel and an outer layer spiral cooling flow channel arranged on the outer circle of the stator of the magnetic suspension motor.
[0022] Figure 2 The structure schematic diagram of the magnetic suspension motor rotor cooling system is shown. As shown in the figure, Figure 2As shown, the magnetic levitation motor includes: a stator, a rotor, an end cover 4, and a housing 7; the stator includes: a stator core 1 and windings 2; the rotor includes: a shaft 3, a rotor core mounted on the shaft 3, and magnets disposed within the rotor core; an inner spiral cooling channel 5 and an outer spiral cooling channel 6 are provided on the outer circumference of the stator (outer circumference of the stator core 1), that is, the inner spiral cooling channel 5 and the outer spiral cooling channel 6 are cooling channels spirally arranged on the outer circumference of the stator core. The inner spiral cooling channel 5 and the outer spiral cooling channel 6 contain refrigerant. The inner spiral cooling channel and the outer spiral cooling channel are controlled to open and close by different control valves. After the cooling system is turned on (i.e., in the initial state), one of the inner spiral cooling channels and the outer spiral cooling channel is open, and the corresponding control valve opening is the preset initial opening, while the other spiral cooling channel is closed.
[0023] Figure 1 This is a schematic diagram of an embodiment of the control method for the rotor cooling system of a magnetic levitation motor provided by the present invention.
[0024] like Figure 1 As shown, according to an embodiment of the present invention, the control method includes at least steps S110 and S120.
[0025] Step S110: Obtain the reference back EMF of the magnetic levitation motor, and obtain the temperature of the motor rotor of the magnetic levitation motor based on the reference back EMF.
[0026] Specifically, the back EMF of the magnetic levitation motor at room temperature is used as the reference back EMF. Based on the motor voltage equation, the back EMF of the motor is calculated according to parameters during the inverter drive process. The back EMF of the motor changes with the temperature of the magnets, and is thus compared with the reference back EMF at room temperature to obtain the temperature change of the motor magnets and the equivalent motor rotor temperature.
[0027] More specifically, the back electromotive force (EMF) of the magnetic levitation motor rotor is calculated based on the current parameters of the magnetic levitation motor, and this calculated back EMF is used as the back EMF. The parameters may specifically include: rotor electrical angle, stator winding turns, and maximum magnetic flux. The temperature of the motor rotor is calculated based on the reference back EMF, the calculated back EMF, and the indoor ambient temperature.
[0028] According to Faraday's law of electromagnetic induction, the magnitude of the induced electromotive force is directly proportional to the rate of change of magnetic flux: E = -dΦ / dt; Where E is the induced EMF, Φ is the magnetic flux through the winding (unit: Weber, Wb), and the negative sign indicates the direction (Lenz's law, which is ignored here, only the size is concerned). In a permanent magnet synchronous motor, the rotor permanent magnet produces a constant air gap flux. Assuming uniform magnetic flux density, the magnetic flux Φ varies with the rotor angle θ: Φ = Φm*cos(θ); Where Φm is the maximum magnetic flux (unit: Wb), determined by the strength of the permanent magnet and the motor design, and θ is the rotor electrical angle (radians), which varies with time: θ = ωt, ω is the angular velocity (unit: rad / s), then: Φ = Φm*cos(ωt); Assuming the stator winding has N turns, the flux linkage λ (unit: Weber-turn, Wb·turn) is defined as: λ = NΦ = NΦm*cos(ωt); The back EMF is the rate of change of flux linkage, then: E = -dλ / dt = -d[NΦm*cos(ωt)] / dt; Taking the derivative gives: E = -NΦm*(-ωsin(ωt)) = NΦm*ωsin(ωt); In the above formula, E = NΦmωsin(ωt) is the instantaneous value, and its peak value is: E peak = NΦmω; The effective value is E0 = 4.44fNΦm; Where Φ is the magnetic flux through the winding, Φm is the maximum magnetic flux, f is the power frequency, N is the number of turns of the stator winding, and 4.44 is the approximate value of 2π / √2.
[0029] According to the above formula (E0 = 4.44fNΦm), the calculated back EMF E0 of the motor rotor can be calculated; according to the calculated back EMF E0, the reference back EMF E1, and the indoor environment temperature T 内环 , the temperature of the motor rotor can be calculated, which can be calculated according to the following formula: The temperature of the motor rotor = (E1-E0) / E0*k + T 内环 ; Where E0 is the calculated back EMF, E1 is the reference back EMF, which can be the back EMF obtained by testing at room temperature, T 内环 is the indoor environment temperature detected by a temperature sensor, and k is the material temperature sensitivity coefficient, for example, 1000.
[0030] Step S120, according to the temperature of the motor rotor obtained, control the cooling system of the magnetic levitation motor rotor.
[0031] Specifically, when the temperature of the motor rotor is less than or equal to a first preset temperature threshold, the cooling system is controlled to maintain its current state, that is, the currently open spiral cooling channel remains open. When the temperature of the motor rotor is greater than the first preset temperature threshold but less than a second preset temperature threshold, the opening degree of the control valve of the open spiral cooling channel is increased, wherein the opening degree of the control valve can be increased by the first preset opening degree. When the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, the frequency converter is controlled to increase the carrier frequency or the other spiral cooling channel of the cooling system is controlled to open, that is, the control valve of the other spiral cooling channel is controlled to open, and the corresponding control valve opening degree is the first preset opening degree value.
[0032] The frequency converter can increase the carrier wave through program control. Increasing the carrier wave significantly reduces motor current harmonics, thereby reducing additional losses caused by harmonics and reducing heat generation. Another spiral cooling channel is opened by controlling a valve on another spiral cooling channel.
[0033] For example, if the first preset temperature threshold is 50℃ and the second preset temperature threshold is 80℃, when the rotor temperature is less than or equal to 50℃, no action is taken and the cooling system maintains its current state. When the rotor temperature rises above 50℃ but is below 80℃, an action is taken to increase the opening of the spiral cooling channel control valve, increasing the flow of refrigerant into the motor and rapidly reducing the rotor temperature until it is under control (without further significant changes). When the rotor temperature reaches (or is greater than or equal to) 80℃, it proves that the original cooling environment controlled by the solenoid valve is insufficient to meet the current rotor cooling requirements. An action is then taken to open another spiral cooling channel to further increase rotor cooling, and / or, the inverter increases the carrier frequency to reduce current harmonic content and reduce additional rotor losses. At this point, rotor self-heating decreases and cooling increases. The motor temperature is thus brought under control.
[0034] Preferably, when the temperature of the motor rotor is greater than or equal to a second preset temperature threshold, a prompt message is issued. For example, when the rotor temperature is greater than or equal to 80°C, an alarm message is issued at the same time as controlling the opening of another spiral cooling channel to prompt the user.
[0035] To clearly illustrate the technical solution of the present invention, the execution flow of the control method for the cooling system of the magnetic levitation motor rotor provided by the present invention will be described below with a specific embodiment.
[0036] Figure 3 This is a schematic diagram of a specific embodiment of the control method for the cooling system of the magnetic levitation motor rotor provided by the present invention. Figure 3 As shown: When the compressor is running, the motor generates temperature rise, the motor rotor temperature is calculated, and then the data is transmitted to the frequency converter temperature judgment module, and the corresponding instruction is sent to the cooling system according to the temperature judgment condition. When the rotor temperature is ≤50℃, the temperature judgment module does not act according to the instruction, and the cooling system can maintain the present situation. When the rotor temperature rises above 50℃ but below 80℃, the temperature judgment module acts according to the instruction, the opening degree of the electromagnetic valve is increased to increase the flow of the refrigerant flowing into the motor, and the rotor temperature is quickly reduced until the temperature is controlled (no further significant change occurs). When the rotor temperature reaches 80℃, it proves that the original cooling environment controlled by the electromagnetic valve cannot meet the current cooling conditions of the rotor, and then an instruction is issued to open another spiral cooling flow channel to further increase the cooling of the motor rotor. At the same time, the frequency converter increases the carrier wave and reduces the current harmonic content to reduce the additional loss of the rotor. At this time, the rotor itself generates less heat and is cooled more. The motor temperature is controlled.
[0037] The application also provides a control device of the magnetic suspension motor rotor cooling system. The magnetic suspension motor rotor cooling system comprises a motor, a frequency converter and a cooling system. The cooling system comprises an inner layer spiral cooling flow channel and an outer layer spiral cooling flow channel arranged on the outer circle of the stator of the magnetic suspension motor.
[0038] As shown in Figure 2 The magnetic suspension motor comprises a stator, a rotor, an end cover 4 and a machine shell 7. The stator comprises a stator core 1 and a winding 2. The rotor comprises a rotating shaft 3, a rotor core sleeved on the rotating shaft 3 and a magnetic steel arranged in the rotor core. An inner layer spiral cooling flow channel 5 and an outer layer spiral cooling flow channel 6 are arranged on the outer circle of the stator (the outer circumference of the stator core 1), that is, the inner layer spiral cooling flow channel 5 and the outer layer spiral cooling flow channel 6 are spiral cooling flow channels arranged on the outer circumference of the stator core. The inner layer spiral cooling flow channel 5 and the outer layer spiral cooling flow channel 6 contain refrigerant. The inner layer spiral cooling flow channel 5 and the outer layer spiral cooling flow channel 6 are respectively controlled to be opened and closed by different control valves. After the cooling system is opened (that is, the initial state), one of the inner layer spiral cooling flow channel and the outer layer spiral cooling flow channel is opened, and the opening degree of the corresponding control valve is a preset initial opening degree, and the other spiral cooling flow channel is closed.
[0039] Through the above control logic, the rotor temperature can be accurately controlled, the intelligent control of the rotor temperature is realized, and the situations of excessive cooling or insufficient cooling are avoided, the irreversible demagnetization of the rotor at high temperature and the situation of excessive cooling due to low motor temperature are eliminated, the reliability of the system is improved, and the energy efficiency of the unit is ensured.
[0040] Figure 4 is a structural block diagram of an embodiment of the control device of the magnetic suspension motor rotor cooling system provided by the application. As Figure 4As shown, the control device 100 of the magnetic suspension motor rotor cooling system comprises an acquisition unit 110 and a control unit 120.
[0041] The acquisition unit 110 is configured to acquire a reference counter electromotive force of the magnetic suspension motor, and acquire a temperature of a motor rotor of the magnetic suspension motor according to the reference counter electromotive force.
[0042] Specifically, the counter electromotive force of the magnetic suspension motor at normal temperature is detected as the reference counter electromotive force of the magnetic suspension motor. Based on the motor voltage equation, the counter electromotive force of the motor is calculated according to parameters in the frequency converter driving process, and the motor counter electromotive force changes with the temperature of the magnetic steel, thereby compared with the reference counter electromotive force at normal temperature to obtain the temperature change of the motor magnetic steel, and the equivalent motor rotor temperature.
[0043] More specifically, the counter electromotive force of the magnetic suspension motor rotor is calculated according to the current parameters of the magnetic suspension motor as the calculated counter electromotive force, and the parameters specifically can include the rotor electric angle, the stator winding number of turns and the maximum magnetic flux. The temperature of the motor rotor is calculated according to the reference counter electromotive force, the calculated counter electromotive force and the indoor environment temperature.
[0044] According to Faraday's law of electromagnetic induction, the induced electromotive force is proportional to the rate of change of magnetic flux: E=-dΦ / dt; Where E is the induced electromotive force, Φ is the magnetic flux through the winding (unit: weber, Wb), and the negative sign represents the direction (Lenz's law, which is ignored here and only the size is concerned). In a permanent magnet synchronous motor, the rotor permanent magnet produces a constant air gap magnetic flux. Assuming that the magnetic flux density is uniform, the magnetic flux Φ changes with the rotor angle θ: Φ=Φm*cos(θ); Where Φm is the maximum magnetic flux (unit: Wb), determined by the strength of the permanent magnet and the motor design, and θ is the rotor electric angle (radian), which changes with time: θ=ωt, and ω is the angular velocity (unit: rad / s), then: Φ=Φm*cos(ωt); Assuming that the stator winding has N turns, the magnetic flux linkage λ (unit: weber·turn, Wb·turn) is defined as: λ=NΦ=NΦm*cos(ωt); The counter electromotive force is the rate of change of the magnetic flux linkage, then: E=-dλ / dt=-d[NΦm*cos(ωt)] / dt; The derivative is: E=-NΦm*(-ωsin(ωt))=NΦm*ωsin(ωt); In the above formula, E=NΦmωsin(ωt) is the instantaneous value, and the peak value is: E peak = NΦmω; effective value E0=4.44fNΦm; Wherein, Φ is the magnetic flux through the winding, Φm is the maximum magnetic flux, f is the power frequency, N is the number of turns of the stator winding, and 4.44 is the approximate value of 2π / √2.
[0045] According to the above formula (E0=4.44fNΦm), the calculated back EMF E0 of the motor rotor can be calculated; according to the calculated back EMF E0, the reference back EMF E1 and the indoor environment temperature T 内环 , the temperature of the motor rotor can be calculated, and the temperature of the motor rotor can be calculated according to the following formula: Temperature of motor rotor=(E1-E0) / E0*k+T 内环 ; Wherein, E0 is the calculated back EMF, E1 is the reference back EMF, which can be the back EMF obtained by testing at room temperature, T 内环 is the indoor environment temperature, which is detected by a temperature sensor, and k is the material temperature sensitivity coefficient, for example, 1000.
[0046] The control unit 120 is configured to control the cooling system of the magnetic levitation motor rotor according to the temperature of the motor rotor obtained by the acquisition unit.
[0047] Specifically, when the temperature of the motor rotor is less than or equal to the first preset temperature threshold, the cooling system is controlled to maintain the current state; that is, the spiral cooling flow channel that is currently opened is maintained. When the temperature of the motor rotor is greater than the first preset temperature threshold and less than the second preset temperature threshold, the opening degree of the control valve of the opened spiral cooling flow channel is increased, wherein the opening degree of the control valve can be increased by the first preset opening degree; when the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, the frequency converter is controlled to increase the carrier frequency or another spiral cooling flow channel of the cooling system is controlled to be opened, that is, the control valve of another spiral cooling flow channel is controlled to be opened, and the corresponding control valve opening degree is the first preset opening degree value.
[0048] Wherein, the frequency converter can control the carrier to be raised through the program, and after the carrier is raised, the motor current harmonics can be significantly reduced, thereby reducing the additional loss caused by the harmonics and achieving the purpose of reducing heat. By controlling the control valve of another spiral cooling flow channel to open another spiral cooling flow channel.
[0049] For example, the first preset temperature threshold is 50℃, and the second preset temperature threshold is 80℃. When the rotor temperature is less than or equal to 50℃, no action is instructed, and the cooling system remains unchanged. When the rotor temperature is higher than 50℃ but lower than 80℃, an action is instructed to increase the opening degree of the spiral cooling flow channel control valve to increase the flow of refrigerant into the motor, so as to quickly reduce the rotor temperature until the temperature is controlled (no further significant change occurs). When the rotor temperature reaches (is greater than or equal to) 80℃, it is proved that the original cooling environment controlled by the electromagnetic valve cannot meet the current cooling conditions of the rotor. Then, an instruction is issued to open another spiral cooling flow channel to further increase the cooling of the motor rotor, and / or the frequency converter increases the carrier frequency to reduce the current harmonic content and reduce the rotor additional loss. At this time, the rotor heat generation is reduced and the cooling is increased. The motor temperature is controlled.
[0050] Optionally, the device 100 further comprises a prompting unit (not shown) for issuing a prompt information when the temperature of the motor rotor is greater than or equal to the second preset temperature threshold. For example, when the rotor temperature is greater than or equal to 80℃, an alarm information is issued to prompt the user while opening another spiral cooling flow channel.
[0051] The application also provides a storage medium corresponding to the control method of the magnetic suspension motor rotor cooling system, which stores a computer program, and the program is executed by a processor to realize the steps of the foregoing method.
[0052] The application also provides a magnetic suspension motor controller corresponding to the control method of the magnetic suspension motor rotor cooling system, which comprises a processor, a memory, and a computer program stored on the memory and executable on the processor, and the processor executes the program to realize the steps of the foregoing method.
[0053] The application also provides a magnetic suspension motor controller corresponding to the control device of the magnetic suspension motor rotor cooling system, which comprises the control device of the foregoing method.
[0054] The application also provides a computer program product corresponding to the control method of the magnetic suspension motor rotor cooling system, which comprises a computer program, and the computer program is executed by a processor to realize the steps of the foregoing method.
[0055] According to the scheme, the rotor temperature is directly calculated in real time through an analytical method, the cooling system is controlled according to the rotor temperature, the rotor temperature is regulated, when the rotor temperature exceeds a threshold value, the rotor temperature is reduced through the frequency converter to increase the carrier or open a cooling flow channel until the rotor temperature meets the requirements, the cooling of the rotor is adaptively adjusted, the rotor temperature is controlled in real time, and the unit operation is ensured; the rotor cooling system capable of adaptive adjustment is beneficial to improving the unit efficiency.
[0056] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transferred over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions can also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as technology evolves, the underlying functions can change, and it is possible that the functions described above can be implemented by different components not explicitly described.
[0057] In several embodiments provided in the present application, it should be understood that the disclosed technical content can be implemented by other ways. Among them, the above-mentioned device embodiments are only schematic, for example, the division of the units can be a logical function division, and when actually implemented, there can be another division way, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection between units or modules, which can be electrical or other forms.
[0058] The units described as separate components can or can not be physically separated, and the components of the control device can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple units. According to the actual needs, part or all of the units can be selected to achieve the purpose of the embodiment scheme.
[0059] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or the entire or part of the technical solutions that make contributions to the related art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.
[0060] The above only describes the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.
Claims
1. A control method for a magnetic levitation motor rotor cooling system, characterized in that, The cooling system includes: an inner spiral cooling channel and an outer spiral cooling channel disposed on the outer circumference of the stator of the magnetic levitation motor. When the cooling system is activated, one of the inner and outer spiral cooling channels is open, and the other spiral cooling channel is closed. The control method includes: Obtain the reference back EMF of the magnetic levitation motor, and obtain the temperature of the motor rotor of the magnetic levitation motor based on the reference back EMF; The cooling system of the magnetic levitation motor rotor is controlled based on the obtained temperature of the motor rotor. When the temperature of the motor rotor is less than or equal to a first preset temperature threshold, the cooling system is controlled to maintain the current state. When the temperature of the motor rotor is greater than the first preset temperature threshold and less than the second preset temperature threshold, the opening degree of the control valve of the open spiral cooling channel is increased. When the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, the frequency converter is controlled to increase the carrier frequency and / or another spiral cooling channel of the cooling system is opened.
2. The method according to claim 1, characterized in that, The temperature of the motor rotor of the magnetic levitation motor is obtained based on the reference back electromotive force, including: The back electromotive force (EMF) of the magnetic levitation motor rotor is calculated based on the current parameters of the magnetic levitation motor. The parameters include: rotor electrical angle, stator winding turns, and maximum magnetic flux. The temperature of the motor rotor is calculated based on the reference back EMF, the calculated back EMF, and the indoor ambient temperature.
3. The method according to claim 2, characterized in that, The temperature of the motor rotor is calculated based on the reference back EMF, the calculated back EMF, and the indoor ambient temperature, including: Based on the reference back EMF, the calculated back EMF, and the indoor ambient temperature, the temperature of the motor rotor is calculated using the following formula: Motor rotor temperature = (E1 - E0) / E0 * k + T 内环 ; Where E0 is for calculating the back electromotive force, E1 is for detecting the back electromotive force, and T... 内环 is the indoor ambient temperature, and k is the material temperature sensitivity coefficient.
4. The method according to any one of claims 1-3, characterized in that, Also includes: When the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, a prompt message is issued.
5. A control device for a magnetic levitation motor rotor cooling system, characterized in that, The cooling system includes: an inner spiral cooling channel and an outer spiral cooling channel disposed on the outer circumference of the stator of the magnetic levitation motor. When the cooling system is activated, one of the inner and outer spiral cooling channels is open, and the other spiral cooling channel is closed. The control device includes: The acquisition unit is used to acquire the reference back EMF of the magnetic levitation motor and acquire the temperature of the motor rotor of the magnetic levitation motor based on the reference back EMF. A control unit is used to control the cooling system of the magnetic levitation motor rotor based on the temperature of the motor rotor obtained by the acquisition unit. When the temperature of the motor rotor is less than or equal to a first preset temperature threshold, the cooling system is controlled to maintain the current state. When the temperature of the motor rotor is greater than the first preset temperature threshold and less than the second preset temperature threshold, the opening degree of the control valve of the open spiral cooling channel is increased. When the temperature of the motor rotor is greater than or equal to the second preset temperature threshold, the frequency converter is controlled to increase the carrier frequency and / or another spiral cooling channel of the cooling system is opened.
6. The apparatus according to claim 5, characterized in that, The acquisition unit acquires the temperature of the motor rotor of the magnetic levitation motor based on the reference back electromotive force, including: The back electromotive force (EMF) of the magnetic levitation motor rotor is calculated based on the current parameters of the magnetic levitation motor. The parameters include: rotor electrical angle, stator winding turns, and maximum magnetic flux. The temperature of the motor rotor is calculated based on the reference back EMF, the calculated back EMF, and the indoor ambient temperature.
7. The apparatus according to claim 6, characterized in that, The temperature of the motor rotor is calculated based on the reference back EMF, the calculated back EMF, and the indoor ambient temperature, including: Based on the reference back EMF, the calculated back EMF, and the indoor ambient temperature, the temperature of the motor rotor is calculated using the following formula: Motor rotor temperature = (E1 - E0) / E0 * k + T 内环 ; Where E0 is for calculating the back electromotive force, E1 is for detecting the back electromotive force, and T... 内环 is the indoor ambient temperature, and k is the material temperature sensitivity coefficient.
8. A storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1-4.
9. A magnetic levitation motor controller, characterized in that, It includes a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of the method of any one of claims 1-4, or includes a control device as described in any one of claims 5-7.
10. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the steps of the method according to any one of claims 1-4.