Magnetic suspension centrifugal pump control method based on COMSOL-SIMULINK joint simulation

Abstract

The invention provides a magnetic suspension centrifugal pump control method based on COMSOL-SIMULINK joint simulation. The magnetic suspension centrifugal pump control method based on COMSOL-SIMULINK joint simulation comprises the following steps that a multi-physical field model of a magnetic suspension centrifugal pump is established in COMSOL; differential processing is carried out on an angular position signal theta output by the multi-physical field model of the magnetic suspension centrifugal pump to obtain the actual operation rotating speed n of the motor, the actual rotating speed n of the motor is compared with the rated rotating speed n *, and ideal shaft current is output after the error is adjusted by a rotating speed PI controller; the ideal shaft current is compared with the actual running current of the motor to form a closed loop; and comparing the displacement of the rotor in the radial direction with an ideal displacement value to realize closed-loop control of the displacement of the rotor. According to the method, multi-physics field coupling modeling provides an accurate physical basis for making a control strategy, and real-time data interaction enables a control system to quickly respond according to the actual operation state of the pump.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation centrifugal pumps, and in particular to a magnetic levitation centrifugal pump control method based on COMSOL-SIMULINK joint simulation. Background Art

[0002] Magnetic levitation centrifugal pumps achieve contactless transmission through magnetic levitation technology, avoiding the friction and wear problems of traditional mechanical bearings and improving the operating stability and efficiency of centrifugal pumps. However, in practical applications, parameter optimization of centrifugal pumps remains a major technical challenge, especially when faced with changes in actual working conditions, measurement errors, and uncertainties, requiring precise optimization and adjustment of the centrifugal pump parameters. Most magnetic levitation centrifugal pump control systems in existing technologies use a single control strategy and are unable to achieve both active and passive control, resulting in insufficient control accuracy and stability under complex working conditions. For example, traditional PID control has poor control effects when facing nonlinear systems and cannot effectively cope with dynamically changing working conditions.

[0003] To improve the control accuracy and stability of magnetic levitation centrifugal pumps, a simulation method that simultaneously considers the effects of multi-physics coupling is required. COMSOL and Simulink co-simulation leverages COMSOL's advanced physical modeling capabilities and Simulink's control theory advantages to achieve cross-platform collaborative design. This co-simulation allows for more accurate simulation of the magnetic levitation centrifugal pump's operating state, optimized control parameters, and improved overall system performance.

[0004] Domestic invention patent CN116173396A "A magnetically levitated centrifugal pump": In this invention, the rotational drive and axial position control of the rotor are completely independent and located on both sides of the rotor body, respectively, with simple control logic. The rotor is fully suspended by the magnetic force between the dynamic magnetic ring and the static magnetic ring. There is no mechanical contact between the rotor and the volute, which reduces heat generation and wear, and reduces the possibility of thrombosis and crushing damage to blood cells. The radial suspension limit of the rotor is achieved by the dynamic magnetic ring and the static magnetic ring. Domestic invention patent CN117536891A "A parameter optimization method and system for a magnetically levitated magnetic-driven centrifugal pump": It relates to the field of centrifugal pump optimization technology. The method includes obtaining basic information of the target liquid to be controlled, optimizing the initial control parameters, establishing mapping and calibration operating parameters, configuring a sensor group and completing the time node segmentation of the startup state and steady state, calling monitoring data to analyze the operating status and generate optimized parameters, and performing operation management through optimized parameters. This solves the problem of insufficient accuracy in centrifugal pump parameter optimization in the prior art and improves the stability and efficiency of the centrifugal pump. Domestic invention patent CN20240326, "A method for controlling electromagnetic resistance based on COMSOL-Simulink joint simulation": First, based on the physical process of resistance generated by a hybrid excitation electromagnetic damper, modeling and numerical calculations are carried out in COMSOL. Then, the COMSOL model is jointly simulated with the Simulink control system. The excitation current of the electromagnetic damper is controlled in real time through Simulink, thereby achieving precise control of the electromagnetic resistance. It can be applied to vehicle braking, mechanical transmission and other fields. Existing patents for magnetic levitation centrifugal pumps mostly focus on specific structural designs or single function implementations, but there are deficiencies in optimizing the overall structure to improve comprehensive performance, such as taking into account multiple requirements such as volume, weight, efficiency, and reliability. In addition, the multi-physical field coupling effect of the fluid magnetic field and the solid is not fully considered, which may lead to discrepancies between theory and practice in actual applications, affecting the performance and reliability of the pump. Through the joint simulation of COMSOL and Simulink, real-time data transmission between the physical model and the control model is achieved, enabling the control system to adjust the control parameters in real time according to the actual operating status of the pump, achieving high-precision, real-time control of the pump, and improving the operating efficiency and stability of the pump, which is not available in existing patents. Summary of the Invention

[0005] To address the existing challenges of insufficient control accuracy and stability for magnetic levitation centrifugal pumps, this paper provides a control method for magnetic levitation centrifugal pumps based on COMSOL-SIMULINK co-simulation. Through precise modeling and real-time control, this method achieves high-precision, real-time control of the magnetic levitation centrifugal pump, improving its operating efficiency and stability. Multi-physics coupling modeling provides an accurate physical basis for developing control strategies, and real-time data interaction enables the control system to rapidly respond to the pump's actual operating status.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] A magnetic levitation centrifugal pump control method based on COMSOL-SIMULINK joint simulation includes the following steps:

[0008] A multi-physics model of a magnetic levitation centrifugal pump is established in COMSOL. The multi-physics model includes the distribution and interaction of electromagnetic fields and flow fields. The multi-physics model outputs the motor's angular position signal θ, the radial displacement of the rotor, and the unilateral magnetic pull applied to the rotor after radial displacement.

[0009] The angular position signal θ output by the multi-physics field model of the magnetic levitation centrifugal pump is differentiated to obtain the actual speed n of the motor. The actual speed n of the motor is compared with the rated speed n. * By comparison, the error e is adjusted by the speed PI controller to output the ideal q-axis current. The actual d-axis current is i Md , the actual q-axis current i Mq ;Will Compared with the actual running time of the motor Md 、i Mq The current deviation e is adjusted by the PI controller and the two-phase voltage of the d-axis is output respectively. Two-phase voltage on q axis The three-phase voltages of the motor are obtained by current regulation and inverter drive, respectively: V Ma 、V Mb 、V Mc ; 3-phase voltage V Ma 、V Mb 、V Mc Determine the 3-phase current i through the power inverter Ma 、i Mb 、i Mc , 3-phase current i Ma 、i Mb 、i Mc Input to the torque coil; 3-phase current i Ma 、i Mb 、i Mc The actual d-axis current i is obtained by coordinate transformation Md and the actual q-axis current i Mq , forming a closed loop;

[0010] The radial displacement of the rotor is compared with the ideal displacement value, and the displacement deviation e is adjusted by the PID controller to produce the suspension force signal in is the suspension force in the d-axis direction, is the suspension force in the q-axis direction; the suspension force signal is converted into Converted into the corresponding suspension coil current signal I Bd and I Bq , where I Bd is the d-axis suspension current, I Bq is the q-axis suspension current; the suspension force F required for the multi-physics field model of the magnetic levitation centrifugal pump is obtained based on the radial force model d and F q , F d is the suspension force required on the d-axis, F q is the suspension force required for the q-axis;

[0011] The multi-physics model of the magnetic levitation centrifugal pump determines the actual displacement of the rotor based on the levitation force required on the d-axis, the levitation force required on the q-axis, the unilateral magnetic pull applied to the rotor after radial displacement, and the external disturbance force on the rotor.

[0012] The actual rotor displacement obtained is used to calculate the suspension force in the next stage to achieve closed-loop control of the rotor displacement.

[0013] Furthermore, a multi-physics field model of the magnetic levitation centrifugal pump is established, including the following steps:

[0014] Construct the three-dimensional geometric structure of the magnetic levitation centrifugal pump;

[0015] Select the k-ω turbulence model and set the material properties and boundary conditions;

[0016] Numerical calculations were performed to obtain the performance parameters of the magnetic levitation centrifugal pump, including the motor's angular position signal θ, the radial displacement of the rotor, and the unilateral magnetic pull applied to the rotor after radial displacement.

[0017] Furthermore, the multi-physics model of the magnetic levitation centrifugal pump solves the actual displacement of the rotor based on the equation of motion, where the equation of motion is:

[0018] F d -F sx -F zx =mx″

[0019] F q -F sy -F zy =my″

[0020] Where: x represents the actual displacement of the rotor in the x direction, y represents the actual displacement of the rotor in the y direction; F d is the suspension force required on the d-axis; F q is the suspension force required on the q axis; F SXis the X-direction component of the unilateral magnetic pull on the rotor after radial displacement; x″ is the actual acceleration of the rotor in the x-direction; y″ is the actual acceleration of the rotor in the y-direction; F SY F is the Y-direction component of the unilateral magnetic pull applied to the rotor after radial displacement; ZX is the X-direction component of the external disturbance force acting on the rotor, F ZY is the Y-direction component of the external disturbance force acting on the rotor; F ZX and F ZY are the parameters of the multiphysics model of the active output magnetic levitation centrifugal pump.

[0021] The beneficial effects of the present invention are:

[0022] The magnetic levitation centrifugal pump control method described in this paper, based on COMSOL-Simulink co-simulation, achieves high-precision, real-time control of the magnetic levitation centrifugal pump through precise modeling and real-time control, thereby improving the pump's operating efficiency and stability. Multi-physics field coupling modeling provides an accurate physical basis for the formulation of control strategies. Real-time data interaction enables the control system to respond rapidly based on the pump's actual operating status. Optimizing the control strategy further enhances control effectiveness, reduces resistance fluctuations, and improves resistance stability. This provides stronger theoretical support and practical guidance for the engineering application of magnetic levitation centrifugal pumps and the selection of control parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. The drawings described below are some embodiments of the present invention. For ordinary technicians in this field, it is obvious that other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a flow chart of the magnetic levitation centrifugal pump control method based on COMSOL-SIMULINK joint simulation described in the present invention.

[0025] Figure 2 Schematic diagram of the overall structure of the magnetic levitation centrifugal pump.

[0026] In the picture:

[0027] 1- centrifugal pump; 2- impeller rotor; 3- stator; 4- torque coil; 5- suspension coil. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] like Figure 2 As shown, an existing magnetic levitation centrifugal pump consists of an L-shaped vertical bearingless permanent magnet thin-film motor (BPMSM) and a centrifugal pump 1. The pump body of the centrifugal pump 1 includes an impeller rotor 2, a volute, and a flow channel. The motor's stator 3 core is wound with two windings: a torque coil 4 and a suspension coil 5, which generate a levitation bias magnetic field. The rotor permanent magnets are integrated with the impeller rotor 2 and placed together in the rear chamber of the centrifugal pump. They are driven by the motor's magnetic field. When the magnetic levitation centrifugal pump is operating normally, the impeller rotor is in a magnetically suspended high-speed rotation state, enabling shaftless rotation.

[0032] like Figure 1 As shown, the magnetic levitation centrifugal pump control method based on COMSOL-SIMULINK joint simulation of the present invention specifically includes the following steps:

[0033] A multiphysics model of a magnetic levitation centrifugal pump was established in COMSOL. The model included the distribution and interaction of electromagnetic and flow fields. This was achieved through the following steps: a. Using geometry tools to construct the three-dimensional geometry of the magnetic levitation centrifugal pump; b. Selecting an appropriate physics module, such as the k-ω turbulence model, and setting material properties and boundary conditions; and c. Performing numerical calculations to obtain the performance parameters of the magnetic levitation centrifugal pump, including the motor's angular position signal θ, the radial displacement of the rotor, and the unilateral magnetic pull applied to the rotor after radial offset.

[0034] The angular position signal θ output by the multi-physics field model of the magnetic levitation centrifugal pump is differentiated to obtain the actual speed n of the motor. The actual speed n of the motor is compared with the rated speed n. * (In progress * =6000r / min), the error e is adjusted by the speed PI controller to output the ideal q-axis current. At this time, the ideal current of the d-axis is

[0035] The actual d-axis current is i Md , the actual q-axis current i Mq ;Will Compared with the actual running time of the motor Md 、i Mq The current deviation e is adjusted by the PI controller and the two-phase voltage of the d-axis is output respectively. Two-phase voltage on q axis The three-phase voltages of the motor are obtained by current regulation and inverter drive, respectively: V Ma 、V Mb 、V Mc Current regulation and inverter drive are existing algorithms, which generally obtain the voltage signal V in the two-phase stationary coordinate system through coordinate transformation (Park inverse transformation) Mα 、V Mβ , which is input into the SVPWM module to control the switching of the inverter and finally obtain the required 3-phase voltage.

[0036] 3-phase voltage V Ma 、V Mb 、V Mc Determine the 3-phase current i through the power inverter Ma 、i Mb 、i Mc , 3-phase current i Ma 、i Mb 、i Mc Input to torque coil 4; another method 3-phase current i Ma 、i Mb 、i Mc The actual d-axis current i is obtained by coordinate transformation (Park inverse transformation)Md and the actual q-axis current i Mq .

[0037] The actual displacement in the rotor radial direction includes x and y, where x represents the x-direction displacement of the rotor and y represents the y-direction displacement of the rotor. * 、y * By comparison, the displacement deviation e is adjusted by the PID controller to produce the suspension force signal is the suspension force in the d-axis direction, is the suspension force in the q-axis direction;

[0038] Then, the force regulation and current conversion formula in the suspension force mathematical model are used to convert the suspension force signal Converted into the corresponding current signal I of the suspension coil 5 Bd , I Bq , I Bd is the d-axis suspension current, I Bq is the q-axis suspension current; import it into the radial force model to obtain the suspension force F required by the system d and F q , F d is the suspension force required on the d-axis, F q is the suspension force required for the q axis.

[0039] The multiphysics model of the magnetic levitation centrifugal pump solves the actual displacement of the rotor based on the equation of motion, where the equation of motion is:

[0040] F d -F sx -F zx =mx″

[0041] F q -F sy -F zy =my″

[0042] Where: x represents the x-direction displacement of the rotor, y represents the y-direction displacement of the rotor; F d is the suspension force required on the d-axis; F q is the suspension force required on the q axis; F SX is the X-direction component of the unilateral magnetic pull on the rotor after radial displacement; x″ is the x-direction acceleration of the rotor; y″ is the y-direction acceleration of the rotor; F SY F is the Y-direction component of the unilateral magnetic pull applied to the rotor after radial displacement; ZX is the X-direction component of the external disturbance force acting on the rotor, F ZY F is the Y-direction component of the external disturbance force acting on the rotor. ZX and F ZYare the parameters of the multiphysics model of the active output magnetic levitation centrifugal pump.

[0043] The actual rotor displacement obtained is used to calculate the suspension force in the next stage. The above processes together realize the closed-loop control of the rotor displacement.

[0044] The magnetic levitation centrifugal pump control method described in this paper, based on COMSOL-Simulink co-simulation, achieves high-precision, real-time control of the magnetic levitation centrifugal pump through precise modeling and real-time control, thereby improving the pump's operating efficiency and stability. Multi-physics field coupling modeling provides an accurate physical basis for the formulation of control strategies. Real-time data interaction enables the control system to respond rapidly based on the pump's actual operating status. Optimizing the control strategy further enhances control effectiveness, reduces resistance fluctuations, and improves resistance stability. This provides stronger theoretical support and practical guidance for the engineering application of magnetic levitation centrifugal pumps and the selection of control parameters.

[0045] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0046] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A magnetic levitation centrifugal pump control method based on COMSOL-SIMULINK joint simulation, characterized in that: The steps include: A multi-physics model of a magnetic levitation centrifugal pump is established in COMSOL. The multi-physics model includes the distribution and interaction of electromagnetic fields and flow fields. The multi-physics model outputs the motor's angular position signal θ, the radial displacement of the rotor, and the unilateral magnetic pull applied to the rotor after radial displacement. The angular position signal θ output by the multi-physics field model of the magnetic levitation centrifugal pump is differentiated to obtain the actual speed n of the motor. The actual speed n of the motor is compared with the rated speed n. * By comparison, the error e is adjusted by the speed PI controller to output the ideal q-axis current. The actual d-axis current is i Md , the actual q-axis current i Mq ;Will Compared with the actual running time of the motor Md 、i Mq The current deviation e is adjusted by the PI controller and the two-phase voltage of the d-axis is output respectively. Two-phase voltage on q axis The three-phase voltages of the motor are obtained by current regulation and inverter drive, respectively: V Ma 、V Mb 、V Mc ; 3-phase voltage V Ma 、V Mb 、V Mc Determine the 3-phase current i through the power inverter Ma 、i Mb 、i Mc , 3-phase current i Ma 、i Mb 、i Mc Input to the torque coil (4); 3-phase current i Ma 、i Mb 、i Mc The actual d-axis current i is obtained by coordinate transformation Md and the actual q-axis current i Mq , forming a closed loop; The radial displacement of the rotor is compared with the ideal displacement value, and the displacement deviation e is adjusted by the PID controller to produce the suspension force signal in is the suspension force in the d-axis direction, is the suspension force in the q-axis direction; the suspension force signal is converted into Converted into the current signal I of the corresponding suspension coil (5) Bd and I Bq , where I Bd is the d-axis suspension current, I Bq is the q-axis suspension current; the suspension force F required for the multi-physics field model of the magnetic levitation centrifugal pump is obtained based on the radial force model d and F q , F d is the suspension force required on the d-axis, F q is the suspension force required for the q-axis; The multi-physics model of the magnetic levitation centrifugal pump determines the actual displacement of the rotor based on the levitation force required on the d-axis, the levitation force required on the q-axis, the unilateral magnetic pull applied to the rotor after radial displacement, and the external disturbance force on the rotor. The actual rotor displacement obtained is used to calculate the suspension force in the next stage to achieve closed-loop control of the rotor displacement.

2. The magnetic levitation centrifugal pump control method based on COMSOL-SIMULINK joint simulation according to claim 1 is characterized in that: Establishing a multi-physics model of a magnetic levitation centrifugal pump includes the following steps: Construct the three-dimensional geometric structure of the magnetic levitation centrifugal pump; Select the k-ω turbulence model and set the material properties and boundary conditions; Numerical calculations were performed to obtain the performance parameters of the magnetic levitation centrifugal pump, including the motor's angular position signal θ, the radial displacement of the rotor, and the unilateral magnetic pull applied to the rotor after radial displacement.

3. The magnetic levitation centrifugal pump control method based on COMSOL-SIMULINK joint simulation according to claim 1 is characterized in that: The multiphysics model of the magnetic levitation centrifugal pump solves the actual displacement of the rotor based on the equation of motion, where the equation of motion is: F d -F sx -F zx =mx″ F q -F sy -F zy =my″ Where: x represents the actual displacement of the rotor in the x direction, y represents the actual displacement of the rotor in the y direction; F d is the suspension force required on the d-axis; F q is the suspension force required on the q axis; F SX is the X-direction component of the unilateral magnetic pull on the rotor after radial displacement; x″ is the actual acceleration of the rotor in the x-direction; y″ is the actual acceleration of the rotor in the y-direction; F SY F is the Y-direction component of the unilateral magnetic pull applied to the rotor after radial displacement; ZX is the X-direction component of the external disturbance force acting on the rotor, F ZY is the Y-direction component of the external disturbance force acting on the rotor; F ZX and F ZY are the parameters of the multiphysics model of the active output magnetic levitation centrifugal pump.

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