Vertical magnetic suspension motor

Abstract

The invention belongs to the technical field of motors, and relates to a vertical magnetic suspension motor. On the basis of the magnetic bearing control module, the cooling control module and the control evaluation module, closed-loop control of the rotor stably suspending at the target position is achieved, oscillation and steady-state errors are reduced, and the control precision is effectively improved; by dynamically calculating the temperature gradient difference and the cooling power regulation and control value and combining the PID controller and the liquid cooling / air cooling cooperation strategy, on-demand cooling is achieved, the cooling energy consumption is reduced, the temperature balance is improved, and the problems of local overheating or too high energy consumption are avoided; by performing normalized weighted analysis on key parameters such as magnetic bearing energy efficiency and cooling efficiency, feeding back control evaluation coefficients in real time and guiding system parameter optimization, the stability and reliability of long-term operation of the motor are ensured, the failure rate of the motor is reduced, the functional integrity is ensured, and system-level optimization is facilitated.

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 drive 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, which 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 and rotational speed at the front and rear ends of the rotor, 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. There are deficiencies in functional integrity, it is difficult to achieve system-level optimization, and it affects long-term stable operation. Summary of the Invention

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

[0009] The object of the present invention can be achieved by 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, which 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 closed-loop control of the rotor through magnetic bearing regulation.

[0010] A cooling control module, which 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 regulate the cooling power to maintain temperature balance.

[0011] A control evaluation module, which evaluates the motor control situation according to the magnetic bearing control data and 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, and respectively recording each ordinal number therein as the actual position of each degree of freedom during the operation of the rotor. Similarly, each ordinal number in the preset position coordinates is respectively recorded as the target position of each degree of freedom during the operation of the rotor, and 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 is calculated, and the obtained difference value is recorded as the deviation value of each degree of freedom during the operation of the rotor.

[0013] 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 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 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 adjustment value, and use it as the input of the electromagnetic coil of the magnetic bearing to generate a corresponding electromagnetic force to achieve the 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, take 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 and load deviation degree of the motor and the 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, and 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. 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, and screen and select the coefficient adjustment value ranked first after descending order 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 a corresponding PID controller for each degree of freedom. 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 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 a corresponding electromagnetic force.

[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 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, then trigger the temperature regulation activation instruction of the PID controller.

[0025] 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.

[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 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.

[0027] During 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, perform normalization processing on 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 includes: comparing 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, 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.

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

[0031] Collectively refer to the magnetic bearing control evaluation situation and 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, provides real-time feedback of the control evaluation coefficient, guides the optimization of system parameters, ensures the stability and reliability of the long-term operation of the motor, reduces its failure rate, guarantees the functional integrity, and helps to achieve 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, other drawings can be obtained based on these drawings without creative efforts.

[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 the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention 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. The schematic diagram of its process 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 a timely manner 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 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 tilting angles about the X and Y axes respectively.

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

[0047] As a preferred feasible example, 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 of the rotor during operation. The operation 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 installed laser velocimeter.

[0049] Using finite element analysis software, a three-dimensional model of the magnetic bearing is established, and electromagnetic-structural coupling analysis is performed on it to obtain the stress and strain distributions of the bearing under different working conditions, and then the stiffness of the bearing is calculated. In the finite element model, by setting material properties, boundary conditions, and loading conditions, etc., the actual working conditions are simulated, and the software can calculate the displacement field under a given load, so as to obtain the relationship between force and displacement and determine 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 installed temperature and humidity sensors and laser vibration measuring instrument.

[0052] 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 the coefficients of the PID controller to which the magnetic bearing belongs.

[0053] In a specific example, the parameter deviation degrees include the bearing stiffness deviation degree, the load deviation degree, and the temperature deviation degree, humidity deviation degree, and vibration deviation degree of the environment, and 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 denoted 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 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, 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 denote them as the regulation values 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 regulation values of each coefficient of the PID controller to which the magnetic bearing belongs corresponding to each parameter deviation degree, and screen the coefficient regulation value ranked first after descending order as the regulation values 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 regulation 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 and converted into an actual current signal, which is input 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 derivative 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 derivative coefficient of the control current signal.

[0063] In a specific example, assume , 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 operation 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 operation of the system, optimize and adjust the PID parameters. 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 derivative coefficient can be increased. Through repeated debugging and optimization, the system can achieve 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, 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 collisions or bearing overloads are likely to occur, leading to system failure. By preferentially eliminating the axial deviation, chain failures caused by instability in the vertical direction can be avoided, significantly enhancing the safety of motor operation. The dynamic adjustment of the radial and tilt deviations can be carried out after the axial stability is achieved, avoiding control signal conflicts caused by simultaneous adjustment of multiple degrees of freedom. Only when the axial deviation exceeds the threshold is high-priority regulation initiated, 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, lowering energy consumption and equipment wear, contributing to extending the service life of the magnetic bearings and the cooling system, and simultaneously 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 initiate 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 the adjustment is 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 achieve closed-loop control of the rotor stably suspended at the target position through magnetic bearing regulation, reducing oscillations and steady-state errors, and effectively improving 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 sliding window mean. If the average temperature exceeds the preset temperature value, it triggers the PID controller to regulate the cooling power to maintain temperature equilibrium. 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 individual 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 arranged. The above-mentioned several detection points arranged 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 is directly collected according to the distributed temperature sensors arranged at each detection point inside the motor.

[0075] As a preferred feasibility 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 select a smaller window. If you are concerned about long-term trends, you should select 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 capture changes more precisely.

[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 feasibility 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. 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.

[0080] 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.

[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.

[0082] And according to the calculation formula obtain the cooling power regulation value , where It 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. It 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. It 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 intense. 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 rapidly increases, 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 it is the case, only the air cooling fan is enabled. When it is the case, the liquid cooling pump and the air cooling fan are enabled to work together. When it is the case, an over-temperature protection signal is triggered and the liquid cooling pump is increased to the 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 cooperation 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] The 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 feasibility example, the magnetic bearing control data includes stability, magnetic bearing energy efficiency, and reliability.

[0091] It should be further noted that the specific acquisition methods for 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 obtains a value through calculation to evaluate the stable 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 operation stability of the motor; conversely, the lower the stability value, the relatively poorer the stable 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 operating 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 operating 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 operating 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 operating duration. The value range is between 0 and 1. A value of 1 means that no failure will occur within this operating duration, and a value of 0 means 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 operating duration.

[0098] For a specific example, if the number of faults is 3 times and the total operating 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 about 4.98%.

[0099] If the number of faults is 8 times and the total operating 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 about 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 respectively the input voltage, input current, and motor efficiency of the motor.

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

[0108] Specifically, by analyzing the control of the magnetic bearing, we can fully understand the performance of the magnetic bearing in the operation of the motor, including stability, energy 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 means that the motor has problems in some key performance indicators and needs further improvement and optimization. After guiding the optimization and improvement and clarifying the advantages and disadvantages of the motor magnetic bearing, it can provide improvement directions for R&D personnel. If the stability score is low, the magnetic bearing control algorithm can be optimized or related parameters can be adjusted to improve the rotor stability; if the energy efficiency is not up to standard, how to optimize the magnetic bearing structure or control strategy can be studied to improve energy efficiency. Predicting potential faults and continuously monitoring the control of the magnetic bearing can timely discover the changing trend of performance indicators. If the reliability gradually decreases, it may indicate that the magnetic bearing is about to fail. Take maintenance measures in advance, such as replacing parts and adjusting operating parameters, to avoid sudden failures causing serious damage to the motor and improve the safety and reliability of the motor operation.

[0109] The cooling efficiency, cooling uniformity and cooling energy efficiency of the motor are extracted from the cooling control data, and after normalization, they are summed up 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 ability 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 efficient and energy-saving 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 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 grasped, covering aspects such as cooling efficiency, cooling uniformity, and cooling energy efficiency, so as to evaluate the overall performance of the cooling system and 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 not good, 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 of 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 performs normalized weighted analysis on key parameters such as the energy efficiency of the magnetic bearing and the cooling efficiency, and provides real-time feedback to control the evaluation coefficient, guiding the optimization of system parameters, ensuring the stability and reliability of the long-term operation of the motor, reducing its failure rate, ensuring functional integrity, and contributing to 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 methods for substitution, 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, wherein the control system is installed on the motor body, and the control system includes: The magnetic bearing control module calculates the deviation between the rotor position coordinates during operation and the preset position coordinates to obtain the deviation value of each degree of freedom, and generates a multi-degree-of-freedom control signal based on the deviation value to achieve rotor closed-loop control through magnetic bearing regulation; The cooling control module calculates the sliding window mean of the time series temperature data of each detection point inside the motor to obtain the average temperature. If the average temperature exceeds the preset temperature value, the PID controller is triggered to adjust the cooling power to maintain temperature balance. The control evaluation module evaluates the motor control status according to the magnetic bearing control data and cooling control data within a cycle and feeds back the evaluation results.

2. A vertical magnetic levitation motor according to claim 1, characterized in that: The specific analysis process of the deviation value of each degree of freedom includes: The position coordinates of the rotor during operation are extracted, and each ordered number therein is recorded as the actual position of each degree of freedom in the rotor operation. Similarly, each ordered number in the preset position coordinates is recorded as the target position of each degree of freedom in the rotor operation. The actual position of each degree of freedom in the rotor operation is subtracted from the target position of the corresponding degree of freedom, and the difference obtained is recorded as the deviation value of each degree of freedom in the rotor operation.

3. A vertical magnetic levitation motor according to claim 2, characterized in that: The specific process of generating a 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 in the same time series of the position coordinates of the rotor during operation. 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 deviation of each parameter of the motor's operating information and environmental information according to the ratio method, and match it with the deviation-PID coefficient mapping table to obtain the control values ​​of each coefficient of the PID controller to which the magnetic bearing belongs; A3. Magnetic bearing control: Based on the deviation value and the control values ​​of each coefficient, a multi-degree-of-freedom control signal is generated through the PID controller of the magnetic bearing, and it is used 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.

4. A vertical magnetic levitation motor according to claim 3, characterized in that: The specific contents of the information analysis include: Extract the rotor speed of the motor, compare it with the current standard rotor speed of the motor, and record the result as the rotor speed deviation of the motor; Extract the bearing stiffness and load of the motor as well as the temperature, humidity and vibration of the environment. Similarly, the bearing stiffness deviation and load deviation of the motor as well as the temperature deviation, humidity deviation and vibration deviation of the environment can be obtained. The coefficient control values ​​of the PID controller belonging to the magnetic bearing corresponding to the rotor speed deviation, bearing stiffness deviation and load deviation of the motor and the temperature deviation, humidity deviation and vibration deviation of the environment are extracted from the deviation-PID coefficient mapping table, and are recorded as the coefficient control values ​​of the PID controller belonging to the magnetic bearing corresponding to the parameter deviations of the motor. The coefficient control values ​​of the PID controller belonging to the magnetic bearing with different coefficients corresponding to the parameter deviations are selected, and the coefficient control values ​​ranked first are selected after arranging in descending order as the coefficient control values ​​of the PID controller belonging to the magnetic bearing.

5. A vertical magnetic levitation motor according to claim 3, 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 the degree of freedom, and the output is the control current signal of the degree of freedom. The control current signal is converted into an actual current signal and input into the electromagnetic coil of the magnetic bearing to generate the corresponding electromagnetic force.

6. A vertical magnetic levitation motor according to claim 5, characterized in that: 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 ,in is the deviation between the actual position and the target position in each degree of freedom, is the proportional term of the control current signal, is the integral term of the control current signal, is the differential term of the control current signal, They are the proportional coefficient, integral coefficient and differential coefficient of the control current signal respectively.

7. A vertical magnetic levitation motor according to claim 1, characterized in that: The specific contents of the cooling control module include: B1. Extract the time series temperature data of each detection point inside the motor, select and set the sliding window size and step size; B2. Place the sliding window at the starting position of the time series 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, and calculate the average temperature value of each detection point arranged inside the motor in the current sliding window for the data in each 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 size, and repeat the above process until the time series temperature data of all detection points inside the entire motor are covered.

8. A vertical magnetic levitation motor according to claim 7, characterized in that: The specific contents of the cooling control module also include: C1. Compare the average temperature of each detection point inside the motor in the current sliding window with the preset temperature value of the corresponding detection point. If the average temperature of a detection point inside the motor in the current sliding window is greater than the preset temperature value of the corresponding detection point, trigger the temperature control activation instruction of the PID controller; C2, subtract the average temperature of the detection point in the sliding window from the preset temperature value of the corresponding detection point to obtain the temperature gradient difference of the detection point in the motor, and bring the temperature gradient difference into the PID controller to calculate the cooling power control value; C3. After triggering the temperature control activation command of the PID controller, the PID controller adjusts the driving parameters of the liquid cooling pump and the air cooling fan of the motor cooling system through closed-loop feedback according to the cooling power control value, so that the actual cooling power tracks the cooling power control value to maintain the internal temperature balance of the motor.

9. The vertical magnetic levitation motor according to claim 1, characterized in that: In the process of evaluating the motor control situation, it is necessary to construct the motor's magnetic bearing control evaluation coefficient and cooling control evaluation coefficient, and the specific process includes: The motor stability, magnetic bearing energy efficiency and reliability are extracted from the magnetic bearing control data, and the normalized data are summed up according to the set weights to obtain the motor magnetic bearing control evaluation coefficient; The cooling efficiency, cooling uniformity and cooling energy efficiency of the motor are extracted from the cooling control data, and after normalization, they are summed up according to the set weights to obtain the cooling control evaluation coefficient of the motor.

10. A vertical magnetic levitation motor according to claim 9, characterized in that: The specific evaluation method of the motor control situation includes: The magnetic bearing control evaluation coefficient of the motor is compared with a preset magnetic bearing control evaluation coefficient threshold value. If the magnetic bearing control evaluation coefficient of the motor is less than the magnetic bearing control evaluation coefficient threshold value, the magnetic bearing control condition of the motor is recorded as unqualified; otherwise, the magnetic bearing control condition of the motor is recorded as qualified; Similarly, the cooling control status of the motor can be obtained; The evaluation status of the magnetic bearing control and the cooling control status of the motor are collectively referred to as the motor control status.

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