A vertical magnetic levitation motor

Abstract

The present invention belongs to the technical field of motors and relates to a vertical magnetic levitation motor. Based on a magnetic bearing control module, a cooling control module, and a control evaluation module, the present invention realizes the closed-loop control of the rotor stably suspended at the target position, reduces oscillation and steady-state error, and effectively improves the control accuracy; by dynamically calculating the temperature gradient difference and the cooling power regulation value, combining a PID controller and a liquid cooling / air cooling collaborative strategy, on-demand cooling is realized, the cooling energy consumption is reduced, the temperature uniformity is improved, and problems such as local overheating or excessive energy consumption are avoided; by performing normalized weighted analysis on key parameters such as the energy efficiency of the magnetic bearing and the cooling efficiency, the control evaluation coefficient is feedback in real time to guide the optimization of system parameters, ensuring the stability and reliability of the long-term operation of the motor, reducing its failure rate, ensuring the functional integrity, and contributing to the realization of system-level optimization.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors and relates to a vertical magnetic levitation motor. Background Art

[0002] Magnetic levitation motors achieve contactless suspension and driving of the rotor through electromagnetic force, and have advantages such as frictionless, high efficiency, and low maintenance, and are widely used in fields such as precision manufacturing and energy equipment. However, its complex control requirements and thermal management problems are still technical difficulties. Especially in the vertical structure, the multi-degree-of-freedom stability of the rotor and the internal temperature balance have a significant impact on the system performance.

[0003] In the prior art, there are also some related solutions involving the analysis of magnetic levitation motors. For example, a patent application for a control system, method, and storage medium of a magnetic levitation motor with the Chinese patent publication number CN113014145B. The control system of this magnetic levitation motor includes a front-end position detection module, a rear-end position detection module, a speed detection module, and a suspension control module; the front-end position detection module is used to obtain the parameter information of the front end of the rotor; the rear-end position detection module is used to obtain the parameter information of the rear end of the rotor; the speed detection module is used to obtain the rotor speed; the suspension control module is respectively connected to the front-end position detection module, the rear-end position detection module, and the speed detection module, and is used to determine the suspension gap of the rotor according to the obtained rotor front-end parameter information, rotor rear-end parameter information, and rotor speed, so as to control the rotor to suspend to the target operating position according to the suspension gap. The above invention can achieve stable suspension control of the magnetic levitation motor and improve the anti-interference ability of the magnetic levitation motor.

[0004] Another patent application for a displacement sensorless magnetic bearing suspension control system and method of a magnetic levitation permanent magnet motor with the Chinese patent publication number CN115498923A includes a control platform module. A data concentration module is provided at the connection end of the control platform module. The control platform module includes a hybrid magnetic bearing axial-radial mathematical model module and a hybrid magnetic bearing radial suspension mathematical model module. An inductance matrix model module is provided at the connection end of the hybrid magnetic bearing axial-radial mathematical model module, and a magnetic field path and distribution data module is provided at the connection end of the hybrid magnetic bearing axial-radial mathematical model module, thereby improving the reliability of suspension control, increasing the speed of the magnetic levitation permanent magnet motor, combining displacement sensorless magnetic bearing suspension control, combining control methods in different operating regions, determining the steady-state operating points of the motor at different speeds and different loads, and realizing the stable maintenance of the magnetic levitation permanent magnet motor in the suspension operating region.

[0005] Although the above solutions propose some solutions for the magnetic levitation motor, there are still certain limitations: (1) Some existing technologies determine the suspension gap by obtaining the parameter information of the front and rear ends of the rotor and the rotational speed, and achieve stable suspension control of the rotor to improve anti-interference ability. However, they ignore the influence of the operating process and the external environment on the rotor position and cannot achieve more accurate closed-loop control of the rotor.

[0006] (2) Some existing technologies determine the steady-state operating points of the motor at different rotational speeds and different loads, and achieve stable maintenance of the magnetic levitation permanent magnet motor in the suspension operating area. However, they lack real-time analysis and dynamic adjustment of the multi-degree-of-freedom deviation of the rotor, which is likely to cause oscillation or deviation.

[0007] (3) Existing technologies lack dynamic adjustment of the cooling strategy and comprehensive evaluation of motor operation based on time-series temperature data, so they cannot avoid problems such as local overheating or excessive energy consumption, have deficiencies in functional integrity, are difficult to achieve system-level optimization, and affect long-term stable operation. Summary of the Invention

[0008] In view of this, to solve the problems raised in the above background technology, a vertical magnetic levitation motor is proposed.

[0009] The object of the present invention can be achieved through the following technical solutions: The present invention provides a vertical magnetic levitation motor, including a motor main body and a control system. The control system is installed on the motor main body. The control system includes: a magnetic bearing control module that calculates the deviation value of each degree of freedom by calculating the deviation between the position coordinates during the operation of the rotor and the preset position coordinates, and generates a multi-degree-of-freedom control signal based on the deviation value to achieve closed-loop control of the rotor through magnetic bearing regulation.

[0010] A cooling control module that calculates the average temperature by performing a moving window average calculation on the time-series temperature data of each detection point arranged inside the motor. If the average temperature exceeds the preset temperature value, the PID controller is triggered to adjust the cooling power to maintain temperature balance.

[0011] A control evaluation module that evaluates the motor control situation based on the magnetic bearing control data and the cooling control data within a period and feeds back the evaluation result.

[0012] The specific analysis process of the deviation value of each degree of freedom includes: extracting the position coordinates during the operation of the rotor, respectively recording each ordinal number therein as the actual position of each degree of freedom during the operation of the rotor. Similarly, respectively recording each ordinal number in the preset position coordinates as the target position of each degree of freedom during the operation of the rotor, and subtracting the actual position of each degree of freedom during the operation of the rotor from the target position of the corresponding degree of freedom. The obtained difference is recorded as the deviation value of each degree of freedom during the operation of the rotor.

[0013] The specific process of generating multi-degree-of-freedom control signals based on deviation values includes: A1. Information detection: Collect the operating information and environmental information of the motor at the position coordinates and time series during the operation of the rotor. The operating information includes the rotor speed, bearing stiffness, and load, and the environmental information includes temperature, humidity, and vibration.

[0014] A2. Information analysis: Analyze the parameter deviation degrees of the operating information and environmental information of the motor according to the ratio method, and match them with the deviation degree - PID coefficient mapping table to obtain the coefficient adjustment values of each PID controller to which the magnetic bearing belongs.

[0015] A3. Magnetic bearing regulation: Generate multi-degree-of-freedom control signals through the PID controller to which the magnetic bearing belongs based on the deviation values and coefficient adjustment values, and use them as the input of the electromagnetic coil of the magnetic bearing to generate corresponding electromagnetic forces to achieve multi-degree-of-freedom closed-loop control of the rotor.

[0016] The specific content of the information analysis includes: Extract the rotor speed of the motor, calculate the ratio of it to the current standard rotor speed of the motor, and record the result as the rotor speed deviation degree of the motor.

[0017] Extract the bearing stiffness and load of the motor and the temperature, humidity, and vibration of the environment. Similarly, the bearing stiffness deviation degree, load deviation degree of the motor, and temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment can be obtained.

[0018] Extract the coefficient adjustment values of each PID controller to which the magnetic bearing belongs corresponding to the rotor speed deviation degree, bearing stiffness deviation degree, and load deviation degree of the motor, and the temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment from the deviation degree - PID coefficient mapping table. Record them as the coefficient adjustment values of each PID controller to which the magnetic bearing belongs corresponding to the deviation degrees of each parameter of the motor, and select different coefficients in the coefficient adjustment values of each PID controller to which the magnetic bearing belongs corresponding to the deviation degrees of each parameter. After descending order sorting, select the coefficient adjustment value ranked first as the coefficient adjustment values of each PID controller to which the magnetic bearing belongs.

[0019] The specific process of the magnetic bearing regulation includes: Design corresponding PID controllers for each degree of freedom respectively. The input of each PID controller is the deviation value of this degree of freedom, and the output is the control current signal of this degree of freedom , amplify it through a power amplifier, convert the amplified control current signal into an actual current signal, and input it into the electromagnetic coil of the magnetic bearing to generate corresponding electromagnetic forces.

[0020] The control current signal specifically includes: According to the calculation formula The control current signal of each PID controller corresponding to each degree of freedom can be obtained where is the deviation value between the actual position and the target position for each degree of freedom. is the proportional term of the control current signal. is the integral term of the control current signal. is the derivative term of the control current signal. are respectively the proportional coefficient, integral coefficient, and derivative coefficient of the control current signal.

[0021] The specific content of the cooling control module includes: B1. Extract the sequential temperature data of each detection point arranged inside the motor, select the sliding window size and step size and set them.

[0022] B2. Place the sliding window at the starting position of the sequential temperature data of each detection point arranged inside the motor, and extract all the temperature values of each detection point arranged inside the current window. For the data in each window, calculate the average temperature value of each detection point arranged inside the motor in the current sliding window, and record it as the average temperature value of each detection point arranged inside the motor in the current sliding window.

[0023] B3. Move the window to the next position according to the set step size, and repeat the above process until the sequential temperature data of each detection point arranged inside the entire motor is covered.

[0024] The specific content of the cooling control module further includes: C1. Compare the average temperature value of each detection point arranged inside the motor in the current sliding window with the preset temperature value of the corresponding detection point. If the average temperature value of a certain detection point arranged inside the motor in the current sliding window is greater than the preset temperature value of the corresponding detection point, trigger the temperature regulation activation instruction of the PID controller.

[0025] C2. Subtract the preset temperature value of the corresponding detection point from the average temperature value of the detection point arranged inside the motor in the sliding window to obtain the temperature gradient difference of the detection point arranged inside the motor, and substitute the temperature gradient difference into the PID controller to calculate the cooling power regulation value.

[0026] C3. After triggering the temperature regulation activation instruction of the PID controller, the PID controller adjusts the drive parameters of the liquid cooling pump and air cooling fan belonging to the motor cooling system according to the cooling power regulation value through closed-loop feedback, so that the actual cooling power tracks the cooling power regulation value to maintain the temperature balance inside the motor.

[0027] In the process of evaluating the motor control situation, it is necessary to construct the magnetic bearing control evaluation coefficient and cooling control evaluation coefficient of the motor. The specific process includes: Extract the stability, magnetic bearing energy efficiency, and reliability of the motor from the magnetic bearing control data, normalize them and sum them according to the set weights to obtain the magnetic bearing control evaluation coefficient of the motor.

[0028] Extract the cooling efficiency, cooling uniformity, and cooling energy efficiency of the motor from the cooling control data, normalize them, and sum them according to the set weights to obtain the cooling control evaluation coefficient of the motor.

[0029] The specific evaluation method for the motor control situation is as follows: Compare the magnetic bearing control evaluation coefficient of the motor with the preset magnetic bearing control evaluation coefficient threshold. If the magnetic bearing control evaluation coefficient of the motor is less than the magnetic bearing control evaluation coefficient threshold, record the magnetic bearing control situation of the motor as unqualified; otherwise, record the magnetic bearing control situation of the motor as qualified.

[0030] Similarly, the cooling control situation of the motor can be obtained.

[0031] Collectively refer to the magnetic bearing control evaluation situation and the cooling control situation of the motor as the motor control situation.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention calculates the rotor position deviation in real time through the magnetic bearing control module, generates a multi-degree-of-freedom control signal based on the deviation value, and realizes the closed-loop control of the rotor stably suspended at the target position through magnetic bearing regulation, reducing oscillation and steady-state error, and effectively improving the control accuracy.

[0033] 2. The present invention analyzes the time-series temperature data based on a sliding window, dynamically calculates the temperature gradient difference and the cooling power regulation value, combines a PID controller and a liquid cooling / air cooling cooperation strategy to achieve on-demand cooling, reduces the cooling energy consumption, improves the temperature uniformity, and avoids problems such as local overheating or excessive energy consumption.

[0034] 3. The present invention performs normalized weighted analysis on key parameters such as magnetic bearing energy efficiency and cooling efficiency through the control evaluation module, and real-time feedback of the control evaluation coefficient to guide the optimization of system parameters, ensuring the stability and reliability of the long-term operation of the motor, reducing its failure rate, ensuring the functional integrity, and contributing to the realization of system-level optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a schematic diagram of the system module connection of the present invention.

[0037] Figure 2 It is a schematic diagram of the magnetic bearing control module process of the present invention.

[0038] Figure 3Schematic diagram of the cooling control module process of the present invention. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] Please refer to Figure 1 As shown, the present invention provides a vertical magnetic levitation motor, and the specific module distribution is as follows: a magnetic bearing control module, a cooling control module, and a control evaluation module. Among them, the connection manner between the modules is: the magnetic bearing control module and the cooling control module are respectively connected to the control evaluation module.

[0041] The magnetic bearing control module calculates the deviation value of each degree of freedom by calculating the deviation between the position coordinates during the operation of the rotor and the preset position coordinates, and generates a multi-degree-of-freedom control signal based on the deviation value, so as to realize the closed-loop control of the rotor through the regulation of the magnetic bearing. Its process schematic diagram is as Figure 2 shown.

[0042] Specifically, during the operation of the system, the actual position and control current and other parameters of the rotor in each degree of freedom are continuously monitored. By monitoring these parameters, it is possible to timely detect whether there are abnormal situations in the system, such as sensor failures, magnetic bearing failures, etc. According to the real-time monitored information, the output of the PID controller is continuously adjusted to keep the rotor always near the target position. If it is found that the position deviation of the rotor exceeds the allowable range, the control current is adjusted in time to increase or decrease the electromagnetic force of the magnetic bearing to correct the deviation.

[0043] It should be further noted that the specific acquisition method of the position coordinates during the operation of the rotor is: using multiple groups of redundant non-contact sensors (such as laser displacement sensors and Hall effect sensors) to real-time collect the coordinates of the rotor in the axial direction (Z direction), radial direction (X, Y directions), and the tilt angles around the X and Y axes during operation, and arranging them in sequence to obtain the position coordinates during the operation of the rotor.

[0044] As a preferred feasible example, the specific analysis process of the deviation value of each degree of freedom includes: extracting the position coordinates during the operation of the rotor, respectively recording each ordered number therein as the actual position of each degree of freedom during the operation of the rotor, and similarly recording each ordered number in the preset position coordinates as the target position of each degree of freedom during the operation of the rotor, and taking the difference between the actual position of each degree of freedom during the operation of the rotor and the target position of the corresponding degree of freedom, and recording the obtained difference as the deviation value of each degree of freedom during the operation of the rotor.

[0045] Exemplarily, the position coordinates of the rotor during operation can be , where are the radial displacements respectively, is the axial displacement, are the tilt angles around the X and Y axes respectively.

[0046] Each of the degrees of freedom includes axial translation (Z direction), radial translation (X, Y directions), and tilt angles (tilt angles around the X and Y axes), a total of 5 degrees of freedom.

[0047] As a preferred feasible example, the specific process of generating a multi-degree-of-freedom control signal based on the deviation value includes: A1. Information detection: Collect the operating information and environmental information of the motor at the same time series as the position coordinates of the rotor during operation. The operating information includes the rotor speed, bearing stiffness, and load, and the environmental information includes temperature, humidity, and vibration.

[0048] It should be further noted that the specific acquisition methods for the rotor speed, bearing stiffness, and load are as follows: The rotor speed is directly detected according to the arranged laser velocimeter.

[0049] Using finite element analysis software, establish a three-dimensional model of the magnetic bearing, perform electromagnetic-structural coupling analysis on it, obtain the stress and strain distributions of the bearing under different working conditions, and then calculate the stiffness of the bearing. In the finite element model, by setting material properties, boundary conditions, and loading conditions, etc., to simulate the actual working conditions, the software can calculate the displacement field under a given load, thereby obtaining the relationship between force and displacement and determining the bearing stiffness.

[0050] Install a torque sensor on the output shaft of the motor to directly measure the torque value output by the motor. Multiply the speed of the motor by its torque value to calculate the load power of the motor, and use it as the load.

[0051] The specific acquisition methods for the temperature, humidity, and vibration are as follows: The temperature, humidity, and vibration are directly detected by using the arranged temperature and humidity sensors and laser vibration measuring instrument.

[0052] A2. Information analysis: Analyze the deviation degrees of each parameter of the motor's operating information and environmental information according to the ratio method, and match them with the deviation degree-PID coefficient mapping table to obtain the regulation values of each coefficient of the PID controller to which the magnetic bearing belongs.

[0053] In a specific example, the deviation degrees of each parameter include the bearing stiffness deviation degree, load deviation degree, and temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment. The coefficients include the proportional coefficient, integral coefficient, and differential coefficient.

[0054] It should be further noted that the deviation degree - PID coefficient mapping table is obtained by establishing the corresponding relationship between each deviation degree and the PID coefficient through a large number of experimental data, as shown in Table 1.

[0055] Table 1 Example of Deviation Degree - PID Coefficient Mapping Table

[0056]

[0057] As a preferred feasible example, the specific content of the information analysis includes: extracting the rotor speed of the motor, taking the ratio of it to the current standard rotor speed of the motor, and the obtained result is recorded as the rotor speed deviation degree of the motor.

[0058] Extract the bearing stiffness, load of the motor, and the temperature, humidity, and vibration of the environment. Similarly, the bearing stiffness deviation degree, load deviation degree of the motor, and the temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment can be obtained.

[0059] Extract the control value of each coefficient of the PID controller to which the magnetic bearing belongs corresponding to the rotor speed deviation degree, bearing stiffness deviation degree, load deviation degree of the motor, and the temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment from the deviation degree - PID coefficient mapping table, and record it as the control value of each coefficient of the PID controller to which the magnetic bearing belongs corresponding to each parameter deviation degree of the motor. Then select different coefficients in the control value of each coefficient of the PID controller to which the magnetic bearing belongs corresponding to each parameter deviation degree, and after sorting in descending order, select the coefficient control value ranked first as the control value of each coefficient of the PID controller to which the magnetic bearing belongs.

[0060] A3. Magnetic Bearing Regulation: Based on the deviation value and each coefficient control value, generate a multi - degree - of - freedom control signal through the PID controller to which the magnetic bearing belongs, and use it as the input of the electromagnetic coil of the magnetic bearing to generate the corresponding electromagnetic force, thereby realizing the multi - degree - of - freedom closed - loop control of the rotor.

[0061] As a preferred feasible example, the specific process of the magnetic bearing regulation includes: designing a corresponding PID controller for each degree of freedom respectively. The input of each PID controller is the deviation value of this degree of freedom, and the output is the control current signal of this degree of freedom , and this output represents the control current required for the magnetic bearing in this degree of freedom to make the rotor return to the target position, which is used to adjust the electromagnetic force of the magnetic bearing, so that the rotor returns to the target position. Since the control signal output by the PID controller is usually a weak - current signal and cannot directly drive the electromagnetic coil of the magnetic bearing, it needs to be amplified by a power amplifier so that it has enough power to drive the electromagnetic coil; convert the amplified control current signal into an actual current signal and input it into the electromagnetic coil of the magnetic bearing to generate the corresponding electromagnetic force, thereby realizing the position control of the rotor in this degree of freedom.

[0062] As a preferred feasibility example, the control current signal specifically includes: According to the calculation formula the control current signal of the PID controller corresponding to each degree of freedom can be obtained , where is the deviation value between the actual position and the target position on each degree of freedom, is the proportional term of the control current signal, and its function is to quickly respond to the deviation, enabling the system to quickly adjust towards the target position. is the integral term of the control current signal, and its function is to eliminate the steady-state error of the system and ensure that the system can finally accurately reach the target position. is the differential term of the control current signal, and its function is to predict the change trend of the deviation, adjust the system in advance, improve the dynamic response performance of the system, and reduce overshoot. are respectively the proportional coefficient, integral coefficient, and differential coefficient of the control current signal.

[0063] A specific example, assuming , so that the control current signal is shown in Table 2.

[0064] Table 2 Example of Control Current Signal

[0065]

[0066] It should be further noted that when the system runs for the first time, it is controlled according to the set initial PID parameters, and the running condition of the rotor is observed. Check whether the rotor can stably hover near the target position and whether there are large oscillations or deviations. According to the running condition of the system, the PID parameters are optimized and adjusted. If the system response is too fast and there is a large overshoot, the proportional coefficient can be appropriately reduced. If there is a steady-state error in the system, the integral coefficient can be increased. If the dynamic response of the system is poor and the oscillation is frequent, the differential coefficient can be increased. Through repeated debugging and optimization, the system reaches the best control effect.

[0067] It should be further noted that the deviation degrees of each degree of freedom are sorted according to the priority, and the axial deviation is used as the primary regulation target, and the radial deviation and tilt angle deviation are used as the secondary regulation targets.

[0068] Specifically, in a vertical magnetic levitation motor, the axial displacement directly affects the gap between the rotor and the stator. If the axial deviation is too large, mechanical collision or bearing overload is likely to occur, resulting in system failure. By preferentially eliminating the axial deviation, the chain failures caused by instability in the vertical direction can be avoided, and the operating safety of the motor can be significantly improved. The dynamic adjustment of the radial and tilt deviations can be carried out after the axial stability is achieved, avoiding the conflict of control signals caused by simultaneous adjustment of multiple degrees of freedom. Only when the axial deviation exceeds the threshold, the high-priority regulation is started, and the radial and tilt deviations are gradually optimized through secondary regulation, avoiding over-response to minor deviations, reducing the frequent operation of the electromagnetic coils of the magnetic bearings, reducing energy consumption and equipment wear, helping to extend the service life of the magnetic bearings and the cooling system, and at the same time reducing the operating cost of the motor.

[0069] A specific example is assumed that during the operation of the motor, it is detected that: axial deviation: +0.3 mm (exceeding the threshold of 0.2 mm); radial deviation: +0.1 mm (not exceeding the threshold of 0.15 mm); tilt angle deviation: +0.02° (not exceeding the threshold of 0.03°).

[0070] PID controller response: Preferentially start the axial regulation, increase the axial electromagnetic force through the PID controller, and reduce the deviation to 0.1 mm within 5 ms. The radial and tilt deviations are gradually optimized through secondary regulation and completed within 20 ms.

[0071] The present invention calculates the rotor position deviation in real time through the magnetic bearing control module, and generates multi-degree-of-freedom control signals based on the deviation values, so as to realize the closed-loop control of the rotor stably suspended at the target position through the magnetic bearing regulation, reduce the oscillation and steady-state error, and effectively improve the control accuracy.

[0072] The cooling control module calculates the average temperature of the time-series temperature data of each detection point arranged inside the motor through a moving window average. If the average temperature exceeds the preset temperature value, it triggers the PID controller to adjust the cooling power to maintain temperature balance. The schematic flow diagram is as Figure 3 shown.

[0073] It should be further noted that the specific arrangement method of each detection point arranged inside the motor is as follows: each key part inside the motor (such as the rotor, stator, and magnetic bearing) is used as an independent detection point, and at the same time, the inside of the motor housing is divided in the form of a plane grid, and each intersection point therein is used as each detection point. The above-mentioned several detection points are collectively referred to as each detection point arranged inside the motor.

[0074] It should be further noted that the specific acquisition method of the time-series temperature data of each detection point arranged inside the motor is as follows: The time-series temperature data of each detection point arranged inside the motor are directly collected according to the distributed temperature sensors arranged at each detection point inside the motor.

[0075] As a preferred feasible example, the specific content of the cooling control module includes: B1. Extract the sequential temperature data of each detection point arranged inside the motor, select the sliding window size and step size and set them.

[0076] Specifically, if you want to capture short-term fluctuations, you can choose a smaller window. If you are concerned about long-term trends, you should choose a larger window. The step size is the distance that the window moves each time it slides. The step size can be equal to the window size (no overlap) or less than the window size (with overlap) to more finely capture changes.

[0077] B2. Place the sliding window at the starting position of the sequential temperature data of each detection point arranged inside the motor, and extract all the temperature values of each detection point arranged inside the current window. For the data in each window, calculate the average temperature value of each detection point arranged inside the motor in the current sliding window, and record it as the average temperature value of each detection point arranged inside the motor in the current sliding window.

[0078] B3. Move the window to the next position according to the set step size, and repeat the above process until the sequential temperature data of each detection point arranged inside the entire motor is covered.

[0079] As a preferred feasible example, the specific content of the cooling control module further includes: C1. Compare the average temperature value of each detection point arranged inside the motor in the current sliding window with the preset temperature value of the corresponding detection point arranged. If the average temperature value of a certain detection point arranged inside the motor in the current sliding window is greater than the preset temperature value of the corresponding detection point arranged, trigger the temperature regulation activation instruction of the PID controller.

[0080] C2. Subtract the preset temperature value of the corresponding detection point arranged from the average temperature value of the detection point arranged inside the motor in the sliding window to obtain the temperature gradient difference of the detection point arranged inside the motor, and substitute the temperature gradient difference into the PID controller to calculate the cooling power regulation value.

[0081] A specific example, according to the calculation formula obtain the temperature gradient difference of the detection point arranged inside the motor , where are respectively the average temperature value of the detection point arranged inside the motor in the sliding window and the preset temperature value of the corresponding detection point arranged.

[0082] And according to the calculation formula obtain the cooling power regulation value , where is the proportional term, whose function is to quickly adjust the cooling power according to the magnitude of the temperature gradient difference. When the temperature gradient difference is large, the proportional term can cause the cooling power to increase or decrease rapidly, enabling the system to quickly respond to temperature changes. For example, if the temperature in a certain area inside the motor rises rapidly, the temperature gradient difference increases, and the proportional term will quickly increase the cooling power to lower the temperature in a timely manner. is the integral term, whose function is to eliminate the steady-state error of the system. During the cooling process, by integrating the temperature gradient difference over time, the temperature deviation is continuously accumulated, thereby adjusting the cooling power to ensure that the temperature inside the motor can finally reach an equilibrium state and eliminate the long-existing temperature deviation. For example, during continuous operation, if there is a small temperature deviation that continuously accumulates, the integral term can gradually adjust the cooling power to eliminate this deviation. is the derivative term, whose function is to predict the temperature change trend based on the rate of change of the temperature gradient difference. If the temperature gradient difference changes rapidly, it indicates that the temperature change trend is relatively drastic. The derivative term will adjust the cooling power in advance, enhancing or weakening the cooling effect, improving the dynamic response performance of the system, and reducing overshoot. For example, when the temperature gradient difference increases rapidly, the derivative term can increase the cooling power in advance to avoid excessive temperature rise.

[0083] By comprehensively considering the temperature gradient difference, its integral, and its derivative, the required cooling power regulation value can be accurately calculated according to the actual temperature change situation inside the motor, enabling the cooling system to more precisely match the heat dissipation requirements of the motor.

[0084] C3. After triggering the temperature regulation activation instruction of the PID controller, the PID controller adjusts the drive parameters of the liquid cooling pump and the air cooling fan belonging to the motor cooling system through closed-loop feedback according to the cooling power regulation value, so that the actual cooling power tracks the cooling power regulation value to maintain the temperature balance inside the motor. Adjusting the cooling power according to the calculation results can effectively maintain the temperature balance inside the motor, avoid local overheating, ensure that all components of the motor operate within an appropriate temperature range, improve the stability and reliability of the motor, and extend the service life of the motor.

[0085] A specific example is that the power distribution unit of the liquid cooling branch and the air cooling branch selects the cooling mode according to the magnitude of the temperature gradient difference: When only the air cooling fan is enabled. When the liquid cooling pump and the air cooling fan work together. When, a over-temperature protection signal is triggered and the liquid cooling pump is increased to its maximum power, as shown in Table 3 specifically.

[0086] Table 3 Example of Cooling Mode Selection

[0087]

[0088] The present invention analyzes time-series temperature data based on a sliding window, dynamically calculates the temperature gradient difference and the cooling power regulation value, and combines a PID controller and a liquid cooling / air cooling collaborative strategy to achieve on-demand cooling, reduce cooling energy consumption, improve temperature uniformity, and avoid problems such as local overheating or excessive energy consumption.

[0089] A control evaluation module evaluates the motor control situation according to the magnetic bearing control data and the cooling control data within a period and feeds back the evaluation result.

[0090] As a preferred feasible example, the magnetic bearing control data includes stability, magnetic bearing energy efficiency, and reliability.

[0091] It should be further noted that the specific ways to obtain the stability, magnetic bearing energy efficiency, and reliability of the motor magnetic bearing are as follows: directly extract the number of rotor offsets of the motor from the motor operation log and the correction response interval duration for each offset , and according to the analysis formula obtain the stability of the motor magnetic bearing , where are respectively the preset offset number threshold and the offset correction response interval duration threshold, , is the number of each offset, is the number of offsets.

[0092] Specifically, in the stability calculation formula of the motor magnetic bearing, is used to reflect the influence of different numbers of offsets on the result. When the value of this item is closer to 0, it indicates that the number of offsets is closer to the ideal situation, and the negative impact on stability is smaller; conversely, the farther the value of this item deviates from 0, the greater the negative impact on stability.

[0093] In the stability calculation formula of the motor magnetic bearing, is used to measure the deviation degree of the actual correction response interval duration compared with the preset threshold during each offset. When the value of this item is closer to 0, it indicates that the correction response duration of the offset is closer to the ideal situation, and the negative impact on stability is smaller; conversely, the farther the value of this item deviates from 0, the greater the negative impact on stability.

[0094] The stability of the motor magnetic bearing comprehensively considers the number of rotor offsets of the motor and the relationship between the correction response interval duration and the preset threshold during each offset, and calculates a value to evaluate the stability degree of the magnetic bearing during operation. The higher the stability value, the faster the magnetic bearing can adjust the rotor back to the stable state when facing rotor offsets, and the better the running stability of the motor; conversely, the lower the stability value, the relatively poorer the stability performance of the magnetic bearing, and the motor is more likely to be unstable during operation.

[0095] The input power and output power of the motor magnetic bearing are respectively detected by using the arranged power analyzers, and the ratio of the output power to the input power is recorded as the magnetic bearing energy efficiency of the motor magnetic bearing.

[0096] The number of faults and the total operation duration of the motor magnetic bearing during operation are directly extracted from the motor operation log, and the ratio of the number of faults of the electromagnetic magnetic bearing during operation to the total operation duration is used to obtain the failure rate of the motor magnetic bearing during operation , and according to the reliability standard calculation formula the reliability of the motor magnetic bearing is obtained , where is the total operation duration of the motor magnetic bearing during operation, is the natural constant.

[0097] Specifically, the reliability of the motor magnetic bearing represents the probability that the motor magnetic bearing does not fail within the given total operation duration. The value range is between 0 and 1. A value of 1 indicates that no failure will occur within this operation duration, and a value of 0 indicates that a failure will definitely occur. It is a key indicator to measure the reliability of the magnetic bearing, helping users intuitively understand the reliability of the magnetic bearing under a specific operation duration.

[0098] In a specific example, if the number of faults is 3 times and the total operation duration is 1500 hours, then the failure rate times / hour, and the reliability of the motor magnetic bearing , that is, within 1500 hours of operation time, the probability that the magnetic bearing does not fail is approximately 4.98%.

[0099] If the number of faults is 8 times and the total operation duration is 2000 hours, then the failure rate times / hour, and the reliability of the motor magnetic bearing , that is, within 2000 hours of operation time, the probability that the magnetic bearing does not fail is approximately 0.034%.

[0100] The cooling control data includes cooling efficiency, cooling uniformity, and cooling energy efficiency.

[0101] It should be further noted that the specific acquisition methods of the cooling efficiency, cooling uniformity, and cooling energy efficiency of the motor cooling system are as follows: According to the cooling efficiency standard calculation formula the cooling efficiency of the motor cooling system is obtained , where are respectively the mass flow rate and specific heat capacity of the cooling medium of the cooling system, is the temperature difference between the inlet and outlet of the cooling system obtained by subtracting the temperatures detected by the temperature sensors at the inlet and outlet of the cooling system, They are the input voltage, input current, and motor efficiency of the motor, respectively.

[0102] Specifically, by quantitatively comparing the heat absorbed by the cooling medium with the input power of the motor, the performance of the cooling system can be intuitively evaluated. When designing the motor cooling system, the cooling efficiency under different schemes can be calculated, and the scheme with high efficiency can be selected to improve the cooling effect and reduce energy consumption.

[0103] According to the standard calculation formula of cooling uniformity the cooling uniformity of the motor cooling system is obtained , where are the maximum value, minimum value, and average value in the sequential temperature data of the th detection point arranged inside the motor, , is the number of the detection points arranged inside the motor, is the number of the detection points arranged inside the motor.

[0104] Specifically, by calculating the cooling uniformity, it can be intuitively understood whether the cooling effects at different positions inside the motor by the cooling system are consistent. If it is found that the cooling uniformity of a certain motor is low, it can be analyzed whether it is due to the unreasonable layout of the cooling system or the uneven distribution of the cooling medium, etc., and then corresponding improvement measures can be taken, such as adjusting the layout of the cooling pipes, optimizing the position of the cooling fan, etc., to improve the performance of the cooling system, ensure that each component of the motor works within an appropriate temperature range, and extend the service life of the motor.

[0105] The input power and output power of the motor cooling system are respectively detected by using the arranged power analyzer, and the ratio of the output power to the input power is recorded as the cooling energy efficiency of the motor cooling system.

[0106] As a preferred feasible example, in the process of evaluating the motor control situation, a magnetic bearing control evaluation coefficient and a cooling control evaluation coefficient of the motor need to be constructed. The specific process includes: extracting the stability, magnetic bearing energy efficiency, and reliability of the motor from the magnetic bearing control data, normalizing them, and then summing them according to the set weights to obtain the magnetic bearing control evaluation coefficient of the motor.

[0107] A specific example is that the weights corresponding to the stability of the motor, the energy efficiency of the magnetic bearing, and the reliability are 0.4, 0.3, and 0.3 respectively. Among them, the stability weight is set to 0.4, highlighting its important position in the evaluation of magnetic bearing control. The stability directly reflects the stability of the rotor during operation, which is crucial for the smooth operation of the motor. A higher weight means that when evaluating the magnetic bearing control situation, more attention is paid to whether the rotor is stably suspended, avoiding large oscillations or offsets. If the stability is not good, even if the energy efficiency and reliability of the magnetic bearing are well-performed, the overall evaluation will be greatly affected. The weights of the energy efficiency and reliability of the magnetic bearing are both set to 0.3, and both also account for a certain proportion in the evaluation system. The energy efficiency of the magnetic bearing is related to the energy utilization efficiency of the motor operation. Higher energy efficiency can reduce energy consumption and improve economic benefits; the reliability reflects the ability of the magnetic bearing to work stably for a long time. High reliability can reduce the frequency of failures and lower the maintenance cost. The same weight for both indicates that while paying attention to the operation stability of the motor, the energy utilization and long-term reliability are also taken into account, achieving the balanced development of comprehensive performance.

[0108] Specifically, by analyzing the magnetic bearing control situation, it is possible to comprehensively understand the performance of the magnetic bearing during the motor operation, including aspects such as stability, energy utilization efficiency, and reliability, so as to evaluate the overall performance of the motor and determine whether the motor meets the design requirements and actual application needs. For example, if the evaluation coefficient of the magnetic bearing control is unqualified, it indicates that there are problems with the motor in some key performance indicators and further improvement and optimization are needed. To guide the optimization and improvement, after clarifying the advantages and disadvantages of the motor magnetic bearing, it can provide the improvement direction for the R & D personnel. If the stability score is low, the magnetic bearing control algorithm can be optimized or relevant parameters can be adjusted specifically to improve the rotor stability; if the energy efficiency does not meet the standard, research can be carried out on how to optimize the magnetic bearing structure or control strategy to improve the energy utilization efficiency. To predict potential failures, continuously monitoring the magnetic bearing control situation can timely detect the change trend of performance indicators. If the reliability gradually decreases, it may indicate that the magnetic bearing is about to fail. Taking preventive maintenance measures in advance, such as replacing parts, adjusting operation parameters, etc., can avoid serious damage to the motor caused by sudden failures and improve the safety and reliability of the motor operation.

[0109] Extract the cooling efficiency, cooling uniformity, and cooling energy efficiency of the motor from the cooling control data, normalize them, and sum them according to the set weights to obtain the cooling control evaluation coefficient of the motor.

[0110] A specific example is that the weights of the cooling efficiency, cooling uniformity, and cooling energy efficiency corresponding to the cooling control evaluation coefficient are 0.5, 0.25, and 0.25 respectively. The weight of the cooling efficiency is set to 0.5, highlighting its key position in the cooling control evaluation. The cooling efficiency is directly related to the ability of the cooling system to remove the heat of the motor. Efficient cooling can ensure that the motor operates at an appropriate temperature, avoiding performance degradation or even damage due to overheating. By giving a higher weight, when evaluating the cooling control situation, the heat dissipation capacity of the cooling system will be focused on. The weights of both the cooling uniformity and the cooling energy efficiency are set to 0.25, and both are also important. The cooling uniformity affects the balance of the temperature distribution inside the motor. A uniform temperature distribution can reduce the stress concentration caused by local overheating and extend the service life of the motor. The cooling energy efficiency involves the energy consumption of the cooling system. An energy-efficient cooling system can reduce the operating cost. The same weight for both indicates that while paying attention to the cooling efficiency, the uniformity of the temperature inside the motor and the energy consumption of the cooling system are also taken into account to optimize the comprehensive performance of the cooling system.

[0111] Specifically, by analyzing the cooling control situation, the performance of the cooling system during the operation of the motor can be comprehensively understood, covering aspects such as cooling efficiency, cooling uniformity, and cooling energy efficiency. Thus, the overall performance of the cooling system can be evaluated to determine whether it meets the heat dissipation requirements of the motor. For example, if the cooling control evaluation coefficient is unqualified, it indicates that there are problems with the cooling system in some key performance indicators and need to be improved. To guide the optimization of the cooling system, after clarifying the advantages and disadvantages of the cooling system, it can provide an optimization direction for technicians. If the cooling efficiency score is low, the heat dissipation structure, cooling medium, etc. of the cooling system can be optimized; if the cooling uniformity is poor, the flow path of the cooling medium can be adjusted or heat dissipation components can be added to improve the temperature distribution; if the cooling energy efficiency does not meet the standard, research can be carried out on how to improve the energy utilization efficiency of the cooling system. To ensure the stable operation of the motor, by continuously monitoring the cooling control situation, the change trend of the performance indicators of the cooling system can be detected in a timely manner. If the cooling uniformity gradually deteriorates, it may cause local overheating of the motor. Taking measures in advance to adjust the cooling strategy can avoid motor failures due to temperature problems and improve the stability and reliability of the motor operation.

[0112] As a preferred feasible example, the specific evaluation method for the motor control situation includes: comparing the magnetic bearing control evaluation coefficient of the motor with a preset magnetic bearing control evaluation coefficient threshold. If the magnetic bearing control evaluation coefficient of the motor is less than the magnetic bearing control evaluation coefficient threshold, the magnetic bearing control situation of the motor is recorded as unqualified; otherwise, the magnetic bearing control situation of the motor is recorded as qualified.

[0113] Similarly, the cooling control situation of the motor can be obtained.

[0114] The magnetic bearing control situation and the cooling control situation of the motor are collectively referred to as the motor control situation.

[0115] Through the control and evaluation module, the present invention conducts normalized weighted analysis on key parameters such as the energy efficiency of the magnetic bearing and the cooling efficiency, and gives real-time feedback on the control evaluation coefficient to guide the optimization of system parameters, ensuring the stability and reliability of the long-term operation of the motor, reducing its failure rate, guaranteeing the functional integrity, and contributing to the realization of system-level optimization.

[0116] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar ways to replace them. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they should fall within the protection scope of the present invention.

Claims

1. A vertical magnetic levitation motor, characterized in that: It includes a motor body and a control system. The control system is installed on the motor body. The control system includes: A magnetic bearing control module that calculates the deviation value of each degree of freedom by calculating the deviation between the position coordinates during the operation of the rotor and the preset position coordinates, and generates a multi-degree-of-freedom control signal based on the deviation value to achieve closed-loop control of the rotor through magnetic bearing regulation. A cooling control module that calculates the average temperature by performing a moving window average calculation on the sequential temperature data of each detection point inside the motor. If the average temperature exceeds the preset temperature value, it triggers a PID controller to regulate the cooling power to maintain temperature balance. A control evaluation module that evaluates the motor control situation based on the magnetic bearing control data and cooling control data within a period and feeds back the evaluation results. The specific process of generating the multi-degree-of-freedom control signal based on the deviation value includes: A1. Information detection: Collect the operation information and environmental information of the motor at the same time series as the position coordinates during the operation of the rotor. The operation information includes the rotor speed, bearing stiffness, and load, and the environmental information includes temperature, humidity, and vibration. A2. Information analysis: Analyze the parameter deviation degrees of the operation information and environmental information of the motor according to the ratio method, and match them with the deviation degree - PID coefficient mapping table to obtain the regulation values of each coefficient of the PID controller to which the magnetic bearing belongs. A3. Magnetic bearing regulation: Generate a multi-degree-of-freedom control signal through the PID controller to which the magnetic bearing belongs based on the deviation value and each coefficient regulation value, and use it as the input of the electromagnetic coil of the magnetic bearing to generate the corresponding electromagnetic force to achieve multi-degree-of-freedom closed-loop control of the rotor.

2. The vertical magnetic levitation motor according to claim 1, wherein: The specific analysis process of each degree-of-freedom deviation value includes: Extract the position coordinates during the operation of the rotor, and record each ordinal number among them as the actual position of each degree of freedom during the operation of the rotor. Similarly, record each ordinal number in the preset position coordinates as the target position of each degree of freedom during the operation of the rotor. Subtract the actual position of each degree of freedom during the operation of the rotor from the target position of the corresponding degree of freedom, and record the obtained difference as the deviation value of each degree of freedom during the operation of the rotor.

3. The vertical magnetic levitation motor according to claim 1, characterized in that: The specific content of the information analysis includes: Extract the rotor speed of the motor, calculate the ratio of it to the current standard rotor speed of the motor, and record the obtained result as the rotor speed deviation degree of the motor. Extract the bearing stiffness and load of the motor and the temperature, humidity, and vibration of the environment. Similarly, the bearing stiffness deviation degree, load deviation degree of the motor, and temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment can be obtained. Extract the regulation values of each coefficient of the PID controller to which the magnetic bearing belongs corresponding to the rotor speed deviation degree, bearing stiffness deviation degree, and load deviation degree of the motor and the temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment from the deviation degree - PID coefficient mapping table, and record them as the regulation values of each coefficient of the PID controller to which the magnetic bearing belongs corresponding to the parameter deviation degrees of the motor. Select different coefficients in the regulation values of each coefficient of the PID controller to which the magnetic bearing belongs corresponding to the parameter deviation degrees, and after descending order sorting, select the coefficient regulation value ranked first as the regulation values of each coefficient of the PID controller to which the magnetic bearing belongs.

4. A vertical magnetic levitation motor according to claim 1, characterized in that: The specific process of the magnetic bearing regulation includes: A corresponding PID controller is designed for each degree of freedom. The input of each PID controller is the deviation value of that degree of freedom, and the output is the control current signal of that degree of freedom. And it is amplified by a power amplifier. The amplified control current signal is converted into an actual current signal and input into the electromagnetic coil of the magnetic bearing to generate a corresponding electromagnetic force.

5. The vertical magnetic levitation motor according to claim 4, wherein: The control current signal specifically includes: According to the calculation formula the control current signal corresponding to the PID controller for each degree of freedom can be obtained , where is the deviation value between the actual position and the target position on each degree of freedom, is the proportional term of the control current signal, is the integral term of the control current signal, is the derivative term of the control current signal, are the proportional coefficient, integral coefficient and derivative coefficient of the control current signal respectively.

6. A vertical magnetic levitation motor according to claim 1, characterized in that: The specific content of the cooling control module includes: B1. Extract the sequential temperature data of each detection point arranged inside the motor, select and set the size and step length of the sliding window; B2. Place the sliding window at the starting position of the sequential temperature data of each detection point arranged inside the motor, and extract all the temperature values of each detection point arranged inside the current window. For the data in each window, calculate the average temperature value of each detection point arranged inside the motor in the current sliding window, and record it as the average temperature value of each detection point arranged inside the motor in the current sliding window; B3. Move the window to the next position according to the set step length, and repeat the above process until the sequential temperature data of each detection point arranged inside the entire motor is covered.

7. The vertical magnetic levitation motor according to claim 6, wherein: The specific content of the cooling control module further includes: C1. Compare the average temperature value of each detection point arranged inside the motor in the current sliding window with the preset temperature value of the corresponding detection point. If the average temperature value of a certain detection point arranged inside the motor in the current sliding window is greater than the preset temperature value of the corresponding detection point, trigger the temperature regulation activation instruction of the PID controller; C2. Subtract the preset temperature value of the corresponding detection point from the average temperature value of the detection point arranged inside the motor in the sliding window to obtain the temperature gradient difference of the detection point arranged inside the motor, and bring the temperature gradient difference into the PID controller to calculate the cooling power regulation value; C3. After triggering the temperature regulation activation instruction of the PID controller, the PID controller adjusts the drive parameters of the liquid cooling pump and the air cooling fan belonging to the motor cooling system through closed-loop feedback according to the cooling power regulation value, so that the actual cooling power tracks the cooling power regulation value to maintain the temperature balance inside the motor.

8. A vertical magnetic levitation motor according to claim 1, characterized in that: To evaluate the motor control situation, it is necessary to construct the magnetic bearing control evaluation coefficient and the cooling control evaluation coefficient of the motor. The specific process includes: Extract the stability, magnetic bearing energy efficiency and reliability of the motor from the magnetic bearing control data, normalize them and sum them according to the set weights to obtain the magnetic bearing control evaluation coefficient of the motor; Extract the cooling efficiency, cooling uniformity and cooling energy efficiency of the motor from the cooling control data, normalize them and sum them according to the set weights to obtain the cooling control evaluation coefficient of the motor.

9. The vertical magnetic levitation motor according to claim 8, wherein: The specific evaluation method of the motor control situation includes: Compare the magnetic bearing control evaluation coefficient of the motor with the preset magnetic bearing control evaluation coefficient threshold. If the magnetic bearing control evaluation coefficient of the motor is less than the magnetic bearing control evaluation coefficient threshold, record the magnetic bearing control situation of the motor as unqualified, otherwise, record the magnetic bearing control situation of the motor as qualified; Similarly, the cooling control situation of the motor can be obtained; Collectively refer to the magnetic bearing control evaluation situation and the cooling control situation of the motor as the motor control situation.

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