A sliding mode control method for bearingless magnetic levitation motor pump suspension soft landing

Abstract

The application relates to motor control technology and discloses a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump, which comprises the following steps: obtaining a motion trajectory equation of a rotor center of the bearingless magnetic suspension motor pump, selecting a motion trajectory sliding mode surface of the rotor center and a motion trajectory sliding mode function, calculating an equivalent control amount of the rotor center when the rotor center is on the motion trajectory sliding mode surface, calculating a correction control amount of the rotor center when the rotor center is not on the motion trajectory sliding mode surface, correcting the motion trajectory equation according to the equivalent control amount and the correction control amount to obtain a corrected motion trajectory equation, and controlling the rotor center of the bearingless magnetic suspension motor pump to safely and softly land according to the corrected motion trajectory equation. The application further discloses a sliding mode control device, equipment and medium for soft landing of the bearingless magnetic suspension motor pump. The application can improve the stability of the sliding mode control for soft landing of the bearingless magnetic suspension motor pump.

Description

TECHNICAL FIELD

[0001] The application relates to the field of motor control technology, and particularly relates to a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump. BACKGROUND

[0002] The bearingless magnetic suspension motor pump is a motor pump in which a traditional mechanical bearing is replaced by a magnetic suspension scheme, so that a pump impeller is suspended in a sealed shell without contact and is driven by a magnetic field of a motor. Since there is no bearing to support the rotor, the suspension performance of the bearingless magnetic suspension motor pump is crucial in product production and use. The suspension performance includes three processes of starting suspension, suspension rotation and stopping suspension landing. Most bearingless magnetic suspension motor pumps do not have a rotor damper or a landing damper. If the stopping suspension landing process of the motor is not controlled, once the suspension motor is powered off, the rotor will inevitably be subjected to a magnetic pulling force in a certain direction. When the magnetic pulling force pulls the rotor to deviate in a certain direction, the rotor will accelerate to collide with the stator, and inevitable friction will occur between the rotor and the stator. For example, in the process of conveying a liquid medium by using the bearingless magnetic suspension motor pump, slight friction between the rotor and the stator can easily generate friction particles to pollute the conveyed medium, and serious collision between the rotor and the stator can easily cause internal material failure of the rotor magnetic steel, thereby reducing the performance of the motor and affecting the flow and lift of the conveyed medium. Therefore, there is an urgent need for a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump to improve the stability of the bearingless magnetic suspension motor pump in the process of suspension landing. SUMMARY

[0003] The application provides a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump, which can improve the stability of the sliding mode control for soft landing of the bearingless magnetic suspension motor pump.

[0004] To achieve the above-mentioned purpose, the application provides a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump, which comprises the following steps.

[0005] An equation of motion trajectory of a rotor center of the bearingless magnetic suspension motor pump in suspension landing is obtained, a motion trajectory sliding mode surface of the rotor center is selected according to the equation of motion trajectory, and a motion trajectory sliding mode function is determined according to the motion trajectory sliding mode surface.

[0006] Whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding mode surface is judged according to the motion trajectory sliding mode surface. When the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding mode surface, an equivalent control amount of the rotor center in suspension landing is calculated.

[0007] When the rotor center of the bearingless magnetic suspension motor pump in suspension landing is not on the motion trajectory sliding mode surface, a correction control amount of the rotor center in suspension landing is calculated.

[0008] correcting the motion trajectory equation according to the equivalent control quantity and the correction control quantity to obtain a corrected motion trajectory equation, and controlling the rotor center of the bearingless magnetic levitation motor pump to safely and softly land according to the corrected motion trajectory equation.

[0009] Optionally, the method further comprises:

[0010] obtaining a coordinate position of the rotor center and a deflection angle of the rotor;

[0011] determining a motion trajectory equation of a plurality of landing trajectory curves according to the coordinate position and the deflection angle.

[0012] Optionally, the method further comprises specifying a kinematic equation of the rotor center according to the motion trajectory equation.

[0013] Optionally, the method further comprises:

[0014] calculating a motion velocity component and an angular velocity component of the rotor center according to a magnetic levitation force model;

[0015] adding a correction function to the motion velocity component and the angular velocity component to obtain the kinematic equation.

[0016] Optionally, the method further comprises:

[0017] obtaining a target control point that the rotor center needs to reach at a current time;

[0018] calculating a deviation vector according to the target control point and an actual control point of the rotor center at the current time;

[0019] judging whether the rotor center of the bearingless magnetic levitation motor pump is on a motion trajectory sliding surface according to the deviation vector.

[0020] Optionally, the method further comprises:

[0021] obtaining a system stability function, and calculating a stability component according to a preset stability condition;

[0022] calculating the correction control quantity according to the stability component and an equivalent control quantity of the rotor center of the bearingless magnetic levitation motor pump.

[0023] Optionally, the calculating the correction control quantity according to the stable component and the equivalent control quantity of the rotor center suspension landing comprises:

[0024] The correction control quantity is calculated by using the following formula:

[0025]

[0026] Wherein, is a sampling period, is a first constant, is a second constant, , is a first component of a sliding mode function, is a second component of a sliding mode function, is a sign function, is an angular component of a first discrete time point, is an angular velocity component of a first discrete time point, is an equivalent control quantity of a velocity component, is an equivalent control quantity of an angular velocity component, is a velocity component equivalent control quantity, is an angular velocity component equivalent control quantity, is a velocity component correction control quantity, is an angular velocity component correction control quantity.

[0027] In order to solve the above problems, the application further provides a sliding mode control device for bearingless magnetic suspension motor pump suspension soft landing, which comprises:

[0028] a motion trajectory equation acquisition module, configured to acquire a motion trajectory equation of a rotor center of the bearingless magnetic suspension motor pump suspension landing, select a motion trajectory sliding mode surface of the rotor center according to the motion trajectory equation, and determine a motion trajectory sliding mode function according to the motion trajectory sliding mode surface;

[0029] a control quantity calculation module, configured to judge whether the rotor center of the bearingless magnetic suspension motor pump suspension landing is on the motion trajectory sliding mode surface according to the motion trajectory sliding mode surface, calculate an equivalent control quantity of the rotor center suspension landing when the rotor center of the bearingless magnetic suspension motor pump suspension landing is on the motion trajectory sliding mode surface, and calculate a correction control quantity of the rotor center suspension landing when the rotor center of the bearingless magnetic suspension motor pump suspension landing is not on the motion trajectory sliding mode surface;

[0030] a landing trajectory correction module, configured to correct the motion trajectory equation to obtain a corrected motion trajectory equation according to the equivalent control quantity and the correction control quantity, and control the rotor center of the bearingless magnetic suspension motor pump to safely soft land according to the corrected motion trajectory equation.

[0031] To solve the above problems, the application further provides an electronic device, which comprises:

[0032] at least one processor; and,

[0033] a memory connected with the at least one processor; wherein,

[0034] the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump.

[0035] To solve the above problems, the application further provides a computer readable storage medium, which stores at least one computer program, and the at least one computer program is executed by a processor in an electronic device to implement the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump.

[0036] The application obtains the motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump in suspension landing, can more accurately control the motion of the rotor by determining the motion trajectory equation of the rotor center, thereby improving the stability and reliability of the pump, in addition, the motion trajectory equation can be corrected by calculating the equivalent control quantity and the correction control quantity, so that the rotor can land according to the preset landing motion trajectory when the motor is stopped, has a larger fault tolerance, can further realize soft landing of the rotor suspension, avoids the collision and rubbing of the stator and the rotor in the landing process, solves the rubbing and collision problem of the magnetic suspension motor pump in soft landing, makes the performance of the magnetic suspension motor pump more reliable, and improves the stability of the bearingless magnetic suspension motor pump in the suspension landing process. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 A flowchart of the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump according to an embodiment of the application is shown;

[0038] Figure 2 A rotor suspension landing schematic diagram of the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump according to an embodiment of the application is shown;

[0039] Figure 3 A trajectory diagram of rotor suspension landing of the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump according to an embodiment of the application is shown;

[0040] Figure 4 A sliding mode control principle diagram of the bearingless magnetic suspension motor pump in suspension landing according to an embodiment of the application is shown.

[0041] Figure 5 A functional module diagram of a sliding mode control device for soft landing of a bearingless magnetic suspension motor pump suspension is provided for an embodiment of the present application.

[0042] Figure 6 A structural schematic diagram of an electronic device for implementing the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump suspension is provided for an embodiment of the present application.

[0043] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0044] It should be understood that the specific embodiments described herein are merely intended to explain the present application and are not intended to limit the present application.

[0045] Embodiments of the present application provide a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump suspension. The execution subject of the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump suspension includes but is not limited to at least one of electronic devices capable of being configured to execute the method provided by the embodiments of the present application, such as a server, a terminal, etc. In other words, the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump suspension can be executed by software or hardware installed in a terminal device or a server device, and the software can be a blockchain platform. The server includes but is not limited to a single server, a server cluster, a cloud server or a cloud server cluster, etc. The server can be a stand-alone server, or a cloud server providing cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content distribution networks (CDN), and big data and artificial intelligence platforms, etc. basic cloud computing services.

[0046] Referring to Figure 1 FIG. 1 shows a flowchart of a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump suspension provided by an embodiment of the present application. In the embodiment, the sliding mode control method for soft landing of a bearingless magnetic suspension motor pump suspension includes:

[0047] S1, obtaining a motion trajectory equation of a rotor center of the bearingless magnetic suspension motor pump suspension, selecting a motion trajectory sliding mode surface of the rotor center according to the motion trajectory equation, and determining a motion trajectory sliding mode function according to the motion trajectory sliding mode surface.

[0048] In the embodiment of the present application, the bearingless magnetic suspension motor pump refers to a motor pump driven by a magnetic field of a motor, in which a traditional mechanical bearing is replaced by a magnetic suspension scheme, so that a pump impeller is suspended in a non-contact sealed shell.

[0049] In the embodiment of the present application, the motion trajectory equation refers to a trajectory equation describing the position of an object in space changing with time, usually taking time as a parameter to give the specific position coordinates of the object at different time points.

[0050] In the embodiment of the present application, the motion trajectory sliding surface refers to a state definition equation of the motion state of the rotor center when the rotor center will move according to the predetermined sliding mode under a certain system state.

[0051] In the embodiment of the present application, the motion trajectory sliding function refers to a function used to describe the relationship between the motion state and the sliding surface, which is composed of one or more state variable functions.

[0052] In the embodiment of the present application, the motion trajectory equation is as follows:

[0053]

[0054] wherein, wherein represents the coordinate position of the rotor center, represents the direction angle of the rotor, represents the coordinate position of the rotor center in the Z direction, is the coordinate change component of is the coordinate change component of is the coordinate change component of is the coordinate change component of is the coordinate change component of .

[0055] In the embodiment of the present application, the motion trajectory sliding function is confirmed by the following steps:

[0056] According to the motion trajectory sliding surface , based on the relationship between the motion trajectory sliding surface and the motion trajectory sliding function, the motion trajectory sliding function is obtained as follows: wherein, transposed matrix, characterizes the approaching speed to the sliding surface, is a discrete time point.

[0057] As an embodiment of the present application, the motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump suspension landing is obtained, comprising:

[0058] Obtaining the coordinate position of the rotor center and the deflection angle of the rotor;

[0059] According to the coordinate position and the deflection angle, the motion trajectory equation of a plurality of landing trajectory curves is determined.

[0060] Further, after the motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump is obtained, the kinematic equation of the rotor center is specified according to the motion trajectory equation.

[0061] Specifically, the kinematic equation of the rotor center is specified according to the motion trajectory equation, including:

[0062] The motion speed component and the angular velocity component of the rotor center are calculated according to the magnetic suspension force model.

[0063] The kinematic equation is obtained after a correction function is added to the motion speed component and the angular velocity component.

[0064] In the embodiment of the application, the kinematic equation refers to a function describing the change relationship of the motion state quantity such as the speed and the acceleration of an object with time.

[0065] In the embodiment of the application, the magnetic suspension force model refers to the interaction between the magnetic field and the suspended object in the magnetic suspension system, and how to generate sufficient force through the magnetic field to overcome the gravity to make the object suspended.

[0066] Exemplarily, the motion speed component and the angular velocity component of the rotor center are calculated according to the magnetic suspension force model, and the following steps are adopted:

[0067] Step 1, the magnetic suspension force model expression is obtained

[0068]

[0069] wherein, is the vacuum permeability; is the driving winding number of turns; is the suspension winding number of turns; is the outer radius of the permanent magnet rotor; is the axial length of the permanent magnet rotor; is the single-sided air gap of the stator and rotor; is the driving winding direct-axis current; is the driving winding quadrature-axis current; is the suspension winding direct-axis current; is the suspension winding quadrature-axis current; is the radial magnetic pull stiffness; is the equivalent excitation current of the permanent magnet; that is, the suspension winding quadrature and direct-axis currents , the driving winding quadrature and direct-axis currents .

[0070] Step 2, the electromagnetic torque equation of the magnetic suspension motor is obtained

[0071]

[0072] wherein, the number of pairs of rotor poles, 、 the direct-axis and quadrature-axis inductances of the drive winding, the rotor permanent magnet flux linkage.

[0073] Step three, according to the mechanical motion equation of the magnetic suspension motor

[0074]

[0075] wherein, is the moment of inertia of the rotor and load of the magnetic suspension motor, is the load torque.

[0076]

[0077] wherein, m is the mass of the rotor and load.

[0078] The embodiment of the present application obtains the motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump in suspension soft landing, and the motion trajectory equation of the rotor center can be determined, so that the motion of the rotor can be more accurately controlled, thereby improving the stability and reliability of the pump.

[0079] S2, judging whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface according to the motion trajectory sliding surface, and when the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface, calculating the equivalent control quantity of the rotor center in suspension landing.

[0080] As an embodiment of the present application, judging whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface according to the motion trajectory sliding surface, comprising:

[0081] obtaining a target control point that the rotor center needs to reach at the current time;

[0082] calculating a deviation vector according to the target control point and the actual control point of the rotor center at the current time;

[0083] judging whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface according to the deviation vector.

[0084] In the embodiment of the present application, the target control point refers to the target position that the rotor center needs to reach at a certain time.

[0085] Exemplarily, the deviation vector can be calculated according to the target control point and the actual control point of the rotor center at the current time by the following steps:

[0086] Step one, in the trajectory motion control of the rotor center position, the target control point reached is set as each time tracking a virtual target control point;

[0087] Step two, the virtual target control point of the rotor center needed to be tracked at the next time is defined as , the current coordinate of the rotor center is , then the deviation vector of the rotor center and the target point is .

[0088] In the embodiment of the application, in the process of rotor suspension landing, if the rotor center can be kept on the trajectory sliding surface (i.e. the rotor center is on the preset landing trajectory and does not deviate from the preset landing trajectory), the rotor suspension landing can be landed according to the preset trajectory.

[0089] As an embodiment of the application, when the rotor center of the bearingless magnetic suspension motor pump suspension landing is on the trajectory sliding surface, the equivalent control amount of the rotor center suspension landing can be calculated by the following steps:

[0090] According to the condition that the rotor center is on the trajectory sliding surface , the design stage of the equivalent control amount can obtain the following formula:

[0091]

[0092] That is

[0093]

[0094] According to the discrete model of the rotor center trajectory, there is:

[0095]

[0096] Wherein the vector , and

[0097]

[0098] Wherein, and are estimated by the following formula

[0099]

[0100] Wherein, is the first compensation function, is the second compensation function.

[0101] Then the equivalent control amount can be calculated as:

[0102] ​

[0103] in, is the sampling period, is a vector of Quantity, is a vector of Quantity, For the The velocity component equivalent control quantity at a discrete time point is For the The angular velocity component at each discrete moment is equivalent to the control quantity.

[0104] S3. When the center of the rotor of the bearingless magnetic levitation motor pump is not located on the sliding surface of the motion trajectory, a correction control amount of the rotor center's suspension landing is calculated.

[0105] As an embodiment of the present invention, when the center of the rotor of the bearingless magnetic levitation motor pump is not located on the sliding surface of the motion trajectory, calculating the correction control amount of the rotor center's levitation landing includes:

[0106] Obtain the system stability function and calculate the stability component according to the preset stability conditions;

[0107] The correction control amount is calculated based on the stabilizing component and the equivalent control amount of the rotor center floating landing.

[0108] In the embodiment of the present invention, the system stability function refers to a function used to analyze the stability of a dynamic system, and a Lyapunov function may be used.

[0109] In the embodiment of the present invention, the Lyapunov function is as follows:

[0110]

[0111] In the embodiment of the present invention, the preset stability condition means that when selecting the corrective control amount, the negative definiteness of the difference must be ensured, that is, .

[0112] Furthermore, the calculation of the correction control amount based on the stabilizing component and the equivalent control amount of the rotor center suspension landing includes:

[0113] The correction control amount is calculated using the following formula:

[0114]

[0115] in, is the sampling period, is the first constant, is the second constant, , is the first component of the sliding mode function, is the second component of the sliding mode function, is the sign function, is the angular component of the rotor at the kth discrete time point, is the angular velocity component of the rotor at the kth discrete time point, is the angular velocity component of the rotor at the kth discrete time point, is the angular velocity component of the rotor at the kth discrete time point, is the angular velocity component of the rotor at the kth discrete time point, is the angular velocity component of the rotor at the kth discrete time point, is the angular velocity component of the rotor at the kth discrete time point, is the angular velocity component of the rotor at the kth discrete time point.

[0116] Exemplarily, the correction control quantity for the rotor center hovering landing is calculated as follows:

[0117] The Lyapunov function is selected as

[0118]

[0119] The difference is

[0120]

[0121] The following needs to be satisfied , so as to ensure the stability of the closed-loop system. Therefore, when selecting the correction control quantity, the negative definiteness of the difference needs to be ensured. According to the negative definiteness of the formula , the following can be derived

[0122]

[0123] wherein a, b>0, is the sign function, is the first component of the sliding mode function, is the second component of the sliding mode function, and the following relationship is satisfied

[0124]

[0125] The correction control quantity is

[0126]

[0127] After the equivalent control quantity and the correction control quantity are obtained, the total control quantity is

[0128]

[0129] The speed of the rotor hovering landing and the angular velocity of the rotor are calculated by the equivalent control quantity and the correction control quantity, so as to correct the compensation function after the system is discretized.

[0130] S4, correcting the motion trajectory equation according to the equivalent control quantity and the correction control quantity to obtain a corrected motion trajectory equation, and controlling the rotor center of the bearingless magnetic suspension motor pump to safely soft-land according to the corrected motion trajectory equation.

[0131] The embodiment of the present application obtains the motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump in the process of soft-landing, can more accurately control the motion of the rotor by determining the motion trajectory equation of the rotor center, thereby improving the stability and reliability of the pump, in addition, the motion trajectory equation can be corrected by calculating the equivalent control quantity and the correction control quantity, so that the rotor can land according to the preset landing motion trajectory when the motor is shut down, has a larger fault tolerance, and further can realize soft-landing of the rotor in suspension, avoids the collision and rubbing of the rotor and the stator in the landing process, solves the rubbing and collision problem of the magnetic suspension motor pump in the process of soft-landing in suspension, makes the performance of the magnetic suspension motor pump more reliable, and improves the stability of the bearingless magnetic suspension motor pump in the process of soft-landing in suspension.

[0132] As shown in Figure 2 , it is a rotor suspension landing schematic diagram of a sliding mode control method for soft-landing of a bearingless magnetic suspension motor pump provided by an embodiment of the present application, wherein 1 represents the inner diameter of the stator (inner rotor) or the outer diameter of the stator (outer rotor), 2 represents the outer diameter of the rotor (inner rotor) or the inner diameter of the rotor (outer rotor) when the rotor is centered, 3 represents the position of the rotor after suspension landing, and O point represents the center position of the stator (also the center position when the rotor is centered).

[0133] As shown in Figure 3 , it is a trajectory schematic diagram of rotor suspension landing of a sliding mode control method for soft-landing of a bearingless magnetic suspension motor pump provided by an embodiment of the present application, wherein A point represents the position of the rotor center when the rotor is eccentric, and B point represents the center position of the rotor after landing. 、 、 、 、 represents the trajectory from a certain suspension position A point of the rotor to the landing position B point, wherein the trajectory 、 、 、 、 is a curve, the landing trajectory of the rotor center is actively controlled, and the mathematical expression of the trajectory can satisfy , wherein represents that the opening of the trajectory curve is towards the positive direction of y, such as the curve and ; when representing the trajectory curve is a straight line, such as curve , representing the trajectory curve opens in the negative direction of y, such as curve and .

[0134] As shown in Figure 4 , it is a bearingless magnetic suspension motor pump suspension soft landing sliding mode control principle diagram provided by an embodiment of the application, including two outer rings and two inner rings, one outer ring is a suspension displacement ring, and the other outer ring is a rotor angle position ring; one inner ring is a suspension current ring, and the other inner ring is a driving current ring.

[0135] The rotor displacement is obtained from the rotor displacement sensor (such as an eddy current sensor, an inductance sensor, a Hall sensor, and a photoelectric sensor) of a permanent magnet magnetic suspension motor (which can also be an asynchronous motor and a synchronous reluctance motor) , and then the rotor displacement is sent to a comparator for comparison with a target displacement, and finally the interpolation of the displacement is sent to a sliding mode trajectory controller to obtain motor suspension winding AC and DC current commands through calculation , the measured suspension winding phase current is converted into suspension AC and DC currents through Park coordinate transformation (three-phase current into synchronous coordinate current) , and then the suspension AC and DC currents are compared with suspension winding AC and DC current commands , and the difference of the comparison is sent to a suspension current controller, wherein the driving current controller includes but is not limited to a PID controller, a sliding mode controller, a hysteresis current controller, and a proportional resonant controller. After the measured suspension current is compared with the calculated suspension current command, the two-phase current of the suspension winding in the stationary coordinate system is obtained through the suspension current controller, and finally the phase voltage drive signal of the suspension winding is analyzed through voltage space vector modulation (SVPWM), and then the power device is driven to supply power to the motor suspension winding.

[0136] The rotor angle position is obtained from the rotor angle sensor (for example, a Hall sensor and a magnetic encoder) of a permanent magnet magnetic suspension motor (which can also be an asynchronous motor and a synchronous reluctance motor) , and the measured rotor angle value (θ1, θ2, or more) is sent to a comparator for comparison with a target angle value θ*, and then the difference of the angle is sent to a trajectory sliding mode controller to analyze the motor driving winding AC and DC current commands through the trajectory sliding mode controller , the measured driving winding phase current is converted into suspension AC and DC currents through Park coordinate transformation , and then the driving AC and DC currents The comparison difference is sent to a drive current controller, wherein the drive current controller includes but is not limited to a PID controller, a sliding mode controller, a hysteresis current controller and a proportional resonant controller.

[0137] The rotor angle position is used in voltage space vector modulation (SVPWM) and current Park coordinate transformation of the two current inner loops.

[0138] As Figure 5 shown in FIG. 1, it is a functional module diagram of a sliding mode control device for soft landing of a bearingless magnetic suspension motor pump according to an embodiment of the present application.

[0139] The sliding mode control device 100 for soft landing of a bearingless magnetic suspension motor pump can be installed in an electronic device. According to the functions to be realized, the sliding mode control device 100 for soft landing of a bearingless magnetic suspension motor pump can include a motion trajectory equation obtaining module 101, a control quantity calculating module 102 and a landing trajectory correcting module 103.

[0140] The module can also be referred to as a unit, which refers to a series of computer program segments capable of being executed by an electronic device processor and capable of completing fixed functions, and stored in a memory of the electronic device.

[0141] In the embodiment, the functions of the modules / units are as follows:

[0142] The motion trajectory equation obtaining module 101 is used to obtain a motion trajectory equation of a rotor center of a bearingless magnetic suspension motor pump, select a motion trajectory sliding mode surface of the rotor center according to the motion trajectory equation, and determine a motion trajectory sliding mode function according to the motion trajectory sliding mode surface.

[0143] In the embodiment, the bearingless magnetic suspension motor pump refers to a motor pump in which a traditional mechanical bearing is replaced by a magnetic suspension scheme, so that a pump impeller is suspended in a sealed shell without contact and driven by a magnetic field of a motor.

[0144] In the embodiment, the motion trajectory equation refers to a trajectory equation describing the position of an object in space changing with time, usually taking time as a parameter to give the specific position coordinates of the object at different time points.

[0145] The motion trajectory sliding surface refers to a state definition equation of the rotor center in a predetermined sliding mode according to a system state.

[0146] The motion trajectory sliding function refers to a function for describing the relationship between the motion state and the sliding surface, and is composed of one or more state variable functions.

[0147] The motion trajectory equation is as follows:

[0148]

[0149] wherein, wherein represents the coordinate position of the rotor center, represents the direction angle of the rotor, represents the coordinate position of the rotor center in the Z direction, is the coordinate change component of is the coordinate change component of is the coordinate change component of is the coordinate change component of is the coordinate change component of is the coordinate change component of

[0150] The motion trajectory sliding function is determined by the following steps in the embodiment of the application:

[0151] According to the motion trajectory sliding surface , the motion trajectory sliding function is obtained based on the relationship between the motion trajectory sliding surface and the motion trajectory sliding function as follows: wherein, is a transposed matrix, characterizes the speed approaching the sliding surface, is a discrete time point.

[0152] As an embodiment of the application, the motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump in suspension landing is obtained, comprising:

[0153] The coordinate position of the rotor center and the deflection angle of the rotor are obtained.

[0154] The motion trajectory equation of the landing trajectory curve is determined according to the coordinate position and the deflection angle.

[0155] Further, after the motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump in suspension landing is obtained, the kinematic equation of the rotor center is specified according to the motion trajectory equation.

[0156] Specifically, the kinematic equation of the rotor center is specified according to the motion trajectory equation, comprising:

[0157] According to the magnetic suspension force model, the motion speed component and the angular velocity component of the rotor center are calculated;

[0158] After adding a correction function to the motion speed component and the angular velocity component, the kinematic equation is obtained.

[0159] In the embodiments of the present application, the kinematic equation refers to a function describing the change relationship of the motion state quantity such as the speed and acceleration of an object with time.

[0160] In the embodiments of the present application, the magnetic suspension force model refers to the interaction between the magnetic field and the suspended object in the magnetic suspension system, and how to generate sufficient force through the magnetic field to overcome the gravity to make the object suspended.

[0161] Exemplarily, the motion speed component and the angular velocity component of the rotor center are calculated according to the magnetic suspension force model, and the following steps are adopted:

[0162] Step one, according to the expression of the magnetic suspension force model

[0163]

[0164] wherein, is the vacuum permeability; is the number of turns of the driving winding; is the number of turns of the suspension winding; is the outer radius of the permanent magnet rotor; is the axial length of the permanent magnet rotor; is the single-sided air gap of the stator and rotor; is the direct-axis current of the driving winding; is the quadrature-axis current of the driving winding; is the direct-axis current of the suspension winding; is the quadrature-axis current of the suspension winding; is the radial magnetic pull stiffness; is the equivalent excitation current of the permanent magnet; that is, the quadrature-axis and direct-axis currents of the suspension winding , the quadrature-axis and direct-axis currents of the driving winding .

[0165] Step two, according to the electromagnetic torque equation of the magnetic suspension motor

[0166]

[0167] wherein, the number of pole pairs of the rotor, , the direct-axis and quadrature-axis inductances of the driving winding, the rotor permanent magnet flux linkage.

[0168] Step three, according to the mechanical motion equation of the magnetic suspension motor

[0169]

[0170] wherein, is the moment of inertia of the rotor and the load of the magnetic bearing motor, is the load torque.

[0171]

[0172] wherein, m is the mass of the rotor and the load.

[0173] The motion trajectory equation of the rotor center of the bearingless magnetic suspension motor pump in suspension landing is obtained, the motion trajectory equation of the rotor center is determined, the motion of the rotor can be more accurately controlled, and therefore the stability and reliability of the pump are improved.

[0174] The control quantity calculation module 102 is configured to determine whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface according to the motion trajectory sliding surface, calculate an equivalent control quantity of the rotor center in suspension landing when the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface, and calculate a correction control quantity of the rotor center in suspension landing when the rotor center of the bearingless magnetic suspension motor pump in suspension landing is not on the motion trajectory sliding surface.

[0175] According to an embodiment of the present application, the determination of whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface according to the motion trajectory sliding surface comprises:

[0176] obtaining a target control point that the rotor center needs to reach at the current time;

[0177] calculating a deviation vector according to the target control point and an actual control point of the rotor center at the current time;

[0178] determining whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface according to the deviation vector.

[0179] In the embodiment of the present application, the target control point refers to a target position that the rotor center needs to reach at a certain time.

[0180] Exemplarily, the calculation of the deviation vector according to the target control point and the actual control point of the rotor center at the current time can adopt the following steps:

[0181] Step 1: in the trajectory motion control of the rotor center position, the target control point reached is set as a virtual target control point tracked at each time.

[0182] Step 2: Define the virtual target control point that needs to be tracked at the next moment of the rotor center as , the current coordinates of the rotor center are , then the deviation vector between the rotor center and the target point is .

[0183] In the embodiment of the present invention, during the rotor suspension landing process, if the (That is, the center of the rotor is on the sliding surface of the motion trajectory and does not deviate from the preset landing trajectory), then the rotor suspension landing can softly land according to the preset trajectory.

[0184] As an embodiment of the present invention, when the center of the rotor of the bearingless magnetic levitation motor pump is on the sliding surface of the motion trajectory, the equivalent control quantity of the rotor center levitation landing is calculated by the following steps:

[0185] According to the condition that the rotor center is on the sliding surface of the motion trajectory , then the equivalent control quantity The following formula can be obtained during the design phase:

[0186]

[0187] Right now

[0188]

[0189] According to the discretization model of the motion trajectory of the rotor center, we have:

[0190]

[0191] where the vector And there are

[0192]

[0193] in, and Estimate it using the following formula

[0194]

[0195] in, is the first compensation function, is the second compensation function.

[0196] Then the equivalent control quantity can be calculated as:

[0197]

[0198] in, is the sampling period, is a vector of Quantity, is a vector of Quantity, For the The velocity component equivalent control quantity at a discrete time point is For the The angular velocity component at each discrete moment is equivalent to the control quantity.

[0199] S3. When the center of the rotor of the bearingless magnetic levitation motor pump is not located on the sliding surface of the motion trajectory, a correction control amount of the rotor center's suspension landing is calculated.

[0200] As an embodiment of the present invention, when the center of the rotor of the bearingless magnetic levitation motor pump is not located on the sliding surface of the motion trajectory, calculating the correction control amount of the rotor center's levitation landing includes:

[0201] Obtain the system stability function and calculate the stability component according to the preset stability conditions;

[0202] The correction control amount is calculated based on the stabilizing component and the equivalent control amount of the rotor center floating landing.

[0203] In the embodiment of the present invention, the system stability function refers to a function used to analyze the stability of a dynamic system, and a Lyapunov function may be used.

[0204] In the embodiment of the present invention, the Lyapunov function is as follows:

[0205]

[0206] In the embodiment of the present invention, the preset stability condition means that when selecting the corrective control amount, the negative definiteness of the difference must be ensured, that is, .

[0207] Furthermore, the calculation of the correction control amount based on the stabilizing component and the equivalent control amount of the rotor center suspension landing includes:

[0208] The correction control amount is calculated using the following formula:

[0209]

[0210] in, is the sampling period, is the first constant, is the second constant, , is the first component of the sliding mode function, is the second component of the sliding mode function, is a symbolic function, is the angular component of the first discrete time point, is the angular component of the first discrete time point, is the angular velocity component of the first discrete time point, is the angular velocity component of the first discrete time point, is the velocity component equivalent control quantity, is the angular velocity component equivalent control quantity, is the velocity component correction control quantity, is the angular velocity component correction control quantity.

[0211] Exemplarily, the correction control quantity of the rotor center suspension landing is calculated, and the steps are as follows:

[0212] The Lyapunov function is selected as

[0213]

[0214] Then the difference is:

[0215]

[0216] The following needs to be met Then the stability of the closed-loop system can be ensured. Therefore, when the correction control quantity is selected, the negative definiteness of the difference needs to be ensured. According to the formula The negative definiteness can be derived as

[0217]

[0218] Wherein a, b>0, is a sign function, is the first component of the sliding mode function, is the second component of the sliding mode function, and the following relationship is met:

[0219]

[0220] Then the correction control quantity can be obtained as

[0221]

[0222] After the equivalent control quantity and the correction control quantity are obtained, the total control quantity is:

[0223]

[0224] The velocity and the angular velocity of the rotor suspension landing are calculated by the equivalent control quantity and the correction control quantity, so as to correct the compensation function after the system is discretized.

[0225] The landing trajectory correction module 103 is configured to correct the motion trajectory equation according to the equivalent control quantity and the correction control quantity to obtain a corrected motion trajectory equation, and control the rotor center of the bearingless magnetic suspension motor pump to land safely and softly according to the corrected motion trajectory equation.

[0226] As shown in Figure 6 FIG. 1 is a structural schematic diagram of an electronic device for implementing a sliding mode control method for soft landing of a bearingless magnetic suspension motor pump according to an embodiment of the present application.

[0227] The electronic device can include a processor 10, a memory 11, a communication bus 12, and a communication interface 13, and can further include a computer program stored in the memory 11 and executable on the processor 10, such as a sliding mode control method program for soft landing of a bearingless magnetic suspension motor pump.

[0228] In some embodiments, the processor 10 can be composed of integrated circuits, for example, a single packaged integrated circuit, or a plurality of packaged integrated circuits with the same function or different functions, including one or more combinations of central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control core of the electronic device, which connects all components of the electronic device through various interfaces and lines, executes programs or modules stored in the memory 11 (such as a sliding mode control method program for soft landing of a bearingless magnetic suspension motor pump), and calls data stored in the memory 11 to perform various functions and process data of the electronic device.

[0229] The memory 11 includes at least one type of readable storage medium, such as a flash memory, a mobile hard disk, a multimedia card, a card-type memory (e.g., an SD or DX memory, etc.), a magnetic memory, a disk, an optical disk, etc. In some embodiments, the memory 11 can be an internal storage unit of an electronic device, such as a mobile hard disk of the electronic device. In other embodiments, the memory 11 can also be an external storage device of the electronic device, such as a plug-in mobile hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 11 can include both an internal storage unit and an external storage device of the electronic device. The memory 11 can be used not only to store application software and various data installed in the electronic device, such as a code of a sliding mode control method program for soft landing of a bearingless magnetic levitation motor pump, but also to temporarily store data that has been output or will be output.

[0230] The communication bus 12 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The bus is configured to enable connection and communication between the memory 11 and at least one processor 10, etc.

[0231] The communication interface 13 is used for communication between the electronic device and other devices, including a network interface and a user interface. Optionally, the network interface can include a wired interface and / or a wireless interface (e.g., a WI-FI interface, a Bluetooth interface, etc.), which is usually used to establish a communication connection between the electronic device and other electronic devices. The user interface can be a display, an input unit (such as a keyboard), and optionally, the user interface can also be a standard wired interface, a wireless interface. Optionally, in some embodiments, the display can be an LED display, a liquid crystal display, a touch liquid crystal display, an OLED (Organic Light-Emitting Diode) touch, etc. The display can also be appropriately referred to as a display screen or a display unit, which is used to display information processed in the electronic device and to display a visualized user interface.

[0232] Figure 6 Only an electronic device with components is shown, and those skilled in the art can understand that, Figure 6The illustrated structure does not constitute a limitation on the electronic device, which can include fewer or more components than those shown, or combine certain components, or arrange the components differently.

[0233] For example, although not shown, the electronic device can also include a power supply (such as a battery) to power the various components. Preferably, the power supply can be logically connected to the at least one processor 10 through a power management device, so that the power management device can implement functions such as charge management, discharge management, and power consumption management. The power supply can also include one or more direct current or alternating current power supplies, recharging devices, power supply fault detection circuits, power supply converters or inverters, power supply status indicators, and any other components. The electronic device can also include various sensors, Bluetooth modules, Wi-Fi modules, and the like, which are not described here.

[0234] It should be understood that the embodiments are only for illustration and are not limited in the scope of the patent application by the structure.

[0235] The program stored in the memory 11 of the electronic device for a bearingless magnetic levitation motor pump levitation soft landing sliding mode control method is a combination of multiple instructions, which, when executed in the processor 10, can achieve:

[0236] Obtaining a motion trajectory equation of the rotor center of the bearingless magnetic levitation motor pump levitation landing, selecting a motion trajectory sliding surface of the rotor center according to the motion trajectory equation, and determining a motion trajectory sliding function according to the motion trajectory sliding surface;

[0237] Determining whether the rotor center of the bearingless magnetic levitation motor pump levitation landing is on the motion trajectory sliding surface according to the motion trajectory sliding surface, and calculating an equivalent control amount of the rotor center levitation landing when the rotor center of the bearingless magnetic levitation motor pump levitation landing is on the motion trajectory sliding surface;

[0238] Calculating a correction control amount of the rotor center levitation landing when the rotor center of the bearingless magnetic levitation motor pump levitation landing is not on the motion trajectory sliding surface;

[0239] Correcting the motion trajectory equation to obtain a corrected motion trajectory equation according to the equivalent control amount and the correction control amount, and controlling the rotor center of the bearingless magnetic levitation motor pump to land safely according to the corrected motion trajectory equation.

[0240] Specifically, the specific implementation method of the processor 10 for the above instructions can refer to the description of the related steps in the corresponding embodiments of the accompanying drawings, which is not described here.

[0241] Further, the modules / units integrated in the electronic device 1 are stored in a computer readable storage medium if they are realized in the form of software function units and sold or used as independent products. The computer readable storage medium can be volatile or non-volatile. For example, the computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM).

[0242] The application further provides a computer readable storage medium, which stores a computer program, and the computer program can realize the following when executed by a processor of an electronic device:

[0243] An equation of a motion trajectory of a rotor center of a bearingless magnetic suspension motor pump in suspension landing is obtained, a motion trajectory sliding surface of the rotor center is selected according to the equation of the motion trajectory, and a motion trajectory sliding function is determined according to the motion trajectory sliding surface;

[0244] It is judged whether the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface according to the motion trajectory sliding surface, and an equivalent control amount of the rotor center in suspension landing is calculated when the rotor center of the bearingless magnetic suspension motor pump in suspension landing is on the motion trajectory sliding surface;

[0245] A correction control amount of the rotor center in suspension landing is calculated when the rotor center of the bearingless magnetic suspension motor pump in suspension landing is not on the motion trajectory sliding surface;

[0246] A modified motion trajectory equation is obtained by correcting the equation of the motion trajectory according to the equivalent control amount and the correction control amount, and the rotor center of the bearingless magnetic suspension motor pump is controlled to land safely and softly according to the modified motion trajectory equation.

[0247] In several embodiments provided in the application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other manners. For example, the above described device embodiments are merely illustrative, and for example, the division of the modules is merely a logical function division, and there can be another division manner in actual implementation.

[0248] The modules illustrated as separated components can or can not be physically separated, and the components illustrated as modules can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments.

[0249] In addition, each functional module in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware, or in the form of hardware plus software function module.

[0250] It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application.

[0251] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any additional reference signs in the claims should not be considered as limiting the claims to which they relate.

[0252] The blockchain referred to in the present application is a new application mode of distributed data storage, peer-to-peer transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain, in essence, is a decentralized database, which is a series of data blocks associated using cryptography. Each data block contains information about a batch of network transactions, used to verify the validity of the information (anti-fake) and generate the next block. The blockchain can include a blockchain underlying platform, a platform product service layer, and an application service layer.

[0253] The embodiments of the present application can acquire and process related data based on artificial intelligence technology. Among them, artificial intelligence (Artificial Intelligence, AI) is to use digital computers or digital computer controlled machines to simulate, extend and expand human intelligence, perceive the environment, acquire knowledge and use knowledge to obtain the best results.

[0254] In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. The plurality of units or devices stated in the system claims can also be implemented by one unit or device through software or hardware. The words first, second, etc. are used to indicate names, not any particular order.

[0255] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A sliding mode control method for soft landing of a bearingless magnetic levitation motor pump, characterized in that: The method comprises: Obtaining a motion trajectory equation of the rotor center of the bearingless magnetic levitation motor pump in suspension, selecting a motion trajectory sliding mode surface of the rotor center according to the motion trajectory equation, and determining a motion trajectory sliding mode function according to the motion trajectory sliding mode surface; According to the motion trajectory sliding surface, it is determined whether the center of the rotor of the bearingless magnetic levitation motor pump that is suspended and landed is on the motion trajectory sliding surface. When the center of the rotor of the bearingless magnetic levitation motor pump that is suspended and landed is on the motion trajectory sliding surface, an equivalent control quantity of the rotor center suspension and landing is calculated. The equivalent control quantity is calculated as: in, is the sampling period, is a vector of Quantity, is a vector of Quantity, For the The velocity component equivalent control quantity at a discrete time point is For the The angular velocity component at each discrete moment is equivalent to the control quantity, where , Characterizes the velocity close to the sliding surface, ,in, is the first compensation function, is the second compensation function; When the center of the rotor of the bearingless magnetic levitation motor pump is not located on the sliding surface of the motion trajectory, a correction control amount of the rotor center's suspension landing is calculated, wherein the correction control amount is calculated using the following formula: in, is the sampling period, is the first constant, is the second constant, , is the first component of the sliding mode function, is the second component of the sliding mode function, is a symbolic function, For the The angular component of a discrete moment, For the The angular velocity component at each discrete moment is equivalent to the control quantity, is the velocity component equivalent control quantity, is the equivalent control quantity of angular velocity component, is the velocity component correction control quantity, is the angular velocity component correction control quantity; The motion trajectory equation is corrected according to the equivalent control amount and the correction control amount to obtain a corrected motion trajectory equation, and the rotor center of the bearingless magnetic levitation motor pump is controlled to land safely and softly according to the corrected motion trajectory equation.

2. The sliding mode control method for soft landing of a bearingless magnetic levitation motor pump according to claim 1, characterized in that: The method of obtaining the motion trajectory equation of the rotor center of the bearingless magnetic levitation motor pump comprises: Obtaining the coordinate position of the rotor center and the deflection angle of the rotor; The motion trajectory equations of a plurality of landing trajectory curves are determined according to the coordinate position and the deflection angle.

3. The sliding mode control method for soft landing of a bearingless magnetic levitation motor pump according to claim 1 or 2, characterized in that: After obtaining the motion trajectory equation of the rotor center of the bearingless magnetic levitation motor pump, the method further includes specifying the kinematic equation of the rotor center according to the motion trajectory equation.

4. The sliding mode control method for soft landing of a bearingless magnetic levitation motor pump according to claim 3, characterized in that: The kinematic equation of the rotor center is specified according to the motion trajectory equation, including: Calculating the motion velocity component and angular velocity component of the rotor center according to the magnetic levitation force model; The kinematic equation is obtained by adding a correction function to the motion velocity component and the angular velocity component.

5. The sliding mode control method for soft landing of a bearingless magnetic levitation motor pump according to claim 1, characterized in that: The determining, based on the motion trajectory sliding surface, whether the center of the suspended rotor of the bearingless magnetic levitation motor pump is on the motion trajectory sliding surface includes: Get the target control point that the rotor center needs to reach at the current moment; Calculating a deviation vector based on the target control point and the actual control point of the rotor center at the current moment; It is determined according to the deviation vector whether the center of the suspended rotor of the bearingless magnetic levitation motor pump is on the sliding mode surface of the motion trajectory.

6. The sliding mode control method for soft landing of a bearingless magnetic levitation motor pump according to claim 1, characterized in that: When the center of the rotor of the bearingless magnetic levitation motor pump is not located on the sliding surface of the motion trajectory, calculating the correction control amount of the rotor center's suspension landing includes: Obtain the system stability function and calculate the stability component according to the preset stability conditions; The correction control amount is calculated based on the stabilizing component and the equivalent control amount of the rotor center floating landing.

7. A sliding mode control device for soft landing of a bearingless magnetic levitation motor pump, characterized in that: The device can implement the sliding mode control method for soft landing of a bearingless magnetic levitation motor pump according to any one of claims 1 to 6, and the device comprises: a motion trajectory equation acquisition module, configured to acquire the motion trajectory equation of the rotor center of the bearingless magnetic levitation motor pump during suspension and landing, select the motion trajectory sliding mode surface of the rotor center according to the motion trajectory equation, and determine the motion trajectory sliding mode function according to the motion trajectory sliding mode surface; a control quantity calculation module, configured to determine, based on the motion trajectory sliding surface, whether the center of the rotor of the bearingless magnetic levitation motor pump that is suspended and landed is on the motion trajectory sliding surface; and to calculate an equivalent control quantity for the suspension and landing of the rotor center when the center of the rotor of the bearingless magnetic levitation motor pump that is suspended and landed is on the motion trajectory sliding surface; and to calculate a corrective control quantity for the suspension and landing of the rotor center when the center of the rotor of the bearingless magnetic levitation motor pump that is suspended and landed is not on the motion trajectory sliding surface; A landing trajectory correction module is used to correct the motion trajectory equation according to the equivalent control amount and the correction control amount to obtain a corrected motion trajectory equation, and control the rotor center of the bearingless magnetic levitation motor pump to safely and softly land according to the corrected motion trajectory equation.

8. An electronic device, characterized in that: The electronic device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the sliding mode control method for soft landing of a bearingless magnetic levitation motor pump as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the sliding mode control method for soft landing of a bearingless magnetic levitation motor pump is implemented.

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