A twelve-pole radial magnetic bearing and a method for controlling the pole configuration thereof

Abstract

This invention discloses a twelve-pole radial magnetic levitation bearing and its pole configuration control method, belonging to the field of magnetic levitation bearing technology. The stator poles of the twelve-pole radial magnetic levitation bearing consist of six pole pairs, with the pole polarity determined to be NSSNNSSNNSSN polarity configuration. Two sensors are used to detect rotor and directional displacement. The six pole pairs constitute three control degrees of freedom distributed at 120°. The pole configuration control method includes a displacement loop control algorithm, electromagnetic force distribution, and pole current distribution. Two-pole-pair, three-pole-pair, and six-pole-pair configurations are used corresponding to the rotor's maximum operating speed ranges of 0-30%, 30%-70%, and 70%-100%. This invention reduces the energy consumption of the magnetic levitation bearing while ensuring its load-bearing capacity by using different pole configurations within different rotor speed ranges, thus meeting the development requirements of high efficiency and high performance for magnetic levitation rotating machinery.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation bearing technology, specifically to a twelve-pole radial magnetic levitation bearing and a method for controlling the configuration of its magnetic poles. Background Technology

[0002] As magnetically levitated rotating machinery develops towards higher power, higher performance, higher efficiency, and wider operating speed ranges, the performance requirements for magnetic bearings, such as load-bearing capacity and power consumption, are constantly increasing. However, there is a contradiction between the load-bearing capacity and power consumption of magnetic bearings: higher load-bearing capacity means greater magnetic pole current and higher power consumption, while lower power consumption means a loss of load-bearing capacity. The unbalanced forces experienced by the rotor vary depending on its operating speed range, resulting in different required load-bearing capacities. Therefore, it is necessary to comprehensively consider both power consumption and load-bearing capacity to design a suitable magnetic bearing control method.

[0003] Existing six-pole, eight-pole, or twelve-pole magnetic levitation bearings operate using a differential current drive control method, requiring all magnetic poles to be activated throughout the entire rotational circumference to ensure sufficient load-bearing capacity. However, this control method generates high power consumption. A twelve-pole magnetic levitation bearing can achieve either high load-bearing capacity or low power consumption by selecting the operating magnetic poles. When the rotor is statically levitated or operating at low speed, the unbalanced force is small, and the magnetic levitation bearing does not need to provide a large load-bearing capacity; only some magnetic poles need to be activated to meet the rotor levitation requirements. When the rotor speed is high, the unbalanced force is large, and the magnetic levitation bearing needs to provide a larger load-bearing capacity. In this case, all magnetic poles can be activated to ensure stable system operation.

[0004] Therefore, based on the above-mentioned problems, this invention proposes a twelve-pole radial magnetic levitation bearing and its pole configuration control method. The goal of this invention is to flexibly select the working poles of the magnetic levitation bearing within the entire operating speed range of magnetically levitated rotating machinery, enabling it to operate in both low-power and high-load-capacity modes, thus meeting the development needs of magnetically levitated rotating machinery for high efficiency, high performance, and a wide operating speed range. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies of the prior art by providing a twelve-pole radial magnetic levitation bearing and a magnetic pole configuration control method thereof. Addressing the high power consumption of existing magnetic levitation bearings, the present invention provides a twelve-pole radial magnetic levitation bearing and proposes a matching magnetic pole configuration control method, enabling magnetic levitation rotating machinery to flexibly select the operating mode of the twelve-pole radial magnetic levitation bearing according to its operating speed, thereby reducing operating power consumption while meeting load-bearing capacity requirements and meeting the development needs of high-efficiency and high-performance magnetic levitation rotating machinery.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A twelve-pole radial magnetic levitation bearing is characterized in that the stator magnetic poles of the twelve-pole radial magnetic levitation bearing are composed of 6 sets of magnetic pole pairs, with each pair consisting of two adjacent magnetic poles. The coils of each magnetic pole pair are independent of each other, and the two magnetic pole coils of each set of magnetic pole pairs are connected in series. The magnetic pole polarity is determined by adjusting the coil winding method and the current direction to a polarity configuration of NSSNNSSNNSSN. There are two pairs of differentially placed displacement sensors on the stator, and the two pairs of displacement sensors are distributed in orthogonal directions to detect the rotor. , The vibration displacement in the direction; the stator magnetic poles are evenly arranged along the circumference, with an angle of 30° between each magnetic pole, forming 6 magnetic pole pairs arranged counterclockwise and numbered 1, 2, 3, 4, 5, and 6 respectively, where magnetic pole pair 1 is connected to the sensor. The angle between the directions is The six magnetic pole pairs are divided into three control degrees of freedom. Magnetic pole pairs 1 and 4 constitute control degree of freedom A, with the positive direction of control degree of freedom A located at magnetic pole pair 1. Magnetic pole pairs 3 and 6 constitute control degree of freedom B, with the positive direction of control degree of freedom B located at magnetic pole pair 3. Magnetic pole pairs 2 and 5 constitute control degree of freedom C, with the positive direction of control degree of freedom C located at magnetic pole pair 5. Control degrees of freedom A are used as the initial axis, and control degrees of freedom B and C are obtained by rotating counterclockwise along the initial axis. The angle between the positive directions of control degrees of freedom A, B, and C is 120°.

[0008] A method for controlling magnetic pole configuration includes the following steps:

[0009] Step S1: The rotor position information is measured by the displacement sensor, and the electromagnetic force required to be output by the magnetic levitation bearing is calculated by the displacement loop control algorithm;

[0010] Step S2: The electromagnetic force distribution module distributes the electromagnetic force calculated by the displacement loop control algorithm to the three control degrees of freedom, which is divided into two-degree-of-freedom distribution and three-degree-of-freedom distribution.

[0011] Step S3: Magnetic pole current distribution. Based on the results of the electromagnetic force distribution module, the current on each magnetic pole pair is configured, which is divided into constant bias current control mode and zero bias current control mode.

[0012] Step S4: Input the current command after magnetic pole current distribution into the power amplifier, and generate the corresponding current in the coil of the twelve-pole radial magnetic levitation bearing to meet the control requirements.

[0013] Furthermore, the magnetic pole configuration control method is divided into two-pole pair configuration, three-pole pair configuration, and six-pole pair configuration; the two-pole pair configuration indicates the selection of the above-mentioned two-degree-of-freedom electromagnetic force distribution and zero-bias current magnetic pole current distribution, the three-pole pair configuration indicates the selection of the above-mentioned three-degree-of-freedom electromagnetic force distribution and zero-bias current magnetic pole current distribution, and the six-pole pair configuration indicates the selection of the above-mentioned three-degree-of-freedom electromagnetic force distribution and constant-bias current magnetic pole current distribution.

[0014] Furthermore, the magnetic pole configuration control method selects the corresponding magnetic pole pair configuration scheme according to the speed range in which the rotor is located: a two-pole pair configuration is selected in the 0-30% range of the highest operating speed, a three-pole pair configuration is selected in the 30%-70% range of the highest operating speed, and a six-pole pair configuration is selected in the 70%-100% range of the highest operating speed.

[0015] Furthermore, the input signal of the displacement loop control algorithm is obtained by subtracting the output signal of the displacement sensor from the coordinates of the geometric center of the magnetic levitation bearing. Represents rotor Displacement error in the direction, Represents rotor The displacement error in the direction; the output signal of the displacement loop control algorithm is calculated by the PID control algorithm, and its output signal Represents the control of electromagnetic force on the rotor Components in direction, Represents the control of electromagnetic force on the rotor Components in direction.

[0016] Furthermore, the input signal for the electromagnetic force distribution is the rotor calculated by the displacement loop control algorithm. , The required control electromagnetic force in the direction , The output signal of the electromagnetic force distribution is the control electromagnetic force in the directions of degrees of freedom A, B, and C. , , It is divided into two-degree-of-freedom control allocation and three-degree-of-freedom control allocation.

[0017] Furthermore, regarding the allocation of the two control degrees of freedom, corresponding to the configuration of the two magnetic pole pairs in the magnetic pole configuration control method, the steps are divided into two steps: control degree of freedom selection and electromagnetic force vector decomposition.

[0018] The specific selection of control degrees of freedom is as follows: control the electromagnetic force vector. , Projected onto control degrees of freedom A, B, and C, the projection length is... , , for:

[0019]

[0020] get , , The control degree of freedom with the smallest projection length is selected, and the other two control degrees of freedom are decomposed into electromagnetic force vectors.

[0021] The electromagnetic force vector decomposition is as follows: If A and B are chosen to control the degrees of freedom, the decomposition equation is expressed as:

[0022]

[0023] If we choose B and C to control the degrees of freedom, the decomposition equation can be expressed as:

[0024]

[0025] If A and C are chosen to control the degrees of freedom, the decomposition equation can be expressed as:

[0026] .

[0027] Furthermore, the three-degree-of-freedom control allocation distributes the electromagnetic force to the three control degrees of freedom A, B, and C, corresponding to a three-pole pair configuration and a six-pole pair configuration. The electromagnetic force allocation equation is as follows:

[0028] .

[0029] Furthermore, in the zero-bias current control mode, only one magnetic pole pair is selected for control current flow in one degree of control freedom, corresponding to a two-pole pair configuration or a three-pole pair configuration; for the magnetic pole current distribution in degree of control freedom A, the current flowed through the two magnetic pole pairs in this degree of control freedom is:

[0030]

[0031] in, Indicates the air permeability. Indicates the number of turns of the coil for each magnetic pole pair. Represents the area of ​​a single magnetic pole. Indicates the air gap of the magnetic levitation bearing. This represents the control electromagnetic force assigned to control degree of freedom A. express , The equivalent displacement projected onto control degree of freedom A is expressed as follows:

[0032]

[0033] The magnetic pole current distribution control method on control degrees of freedom B and C is the same as the zero bias current control mode on control degree of freedom A.

[0034] Furthermore, in the constant bias current control mode for the magnetic pole current distribution, current is applied to both magnetic pole pairs in one degree of freedom, corresponding to a six-pole pair configuration; for the magnetic pole current distribution in degree of freedom A, the current applied to the two magnetic pole pairs in this degree of freedom is:

[0035]

[0036] in, Indicates the bias current. This represents the control electromagnetic force assigned to control degree of freedom A. express , The equivalent displacement projected onto the control degree of freedom A. Indicates the current stiffness value. The values ​​represent displacement stiffness, and their expressions are as follows:

[0037]

[0038] in, Indicates the air permeability. Indicates the number of turns of the coil for each magnetic pole pair. Represents the area of ​​a single magnetic pole. The air gap of the magnetic levitation bearing is indicated; the magnetic pole current distribution control method on the control degrees of freedom B and C is the same as the constant bias current control mode on the control degree of freedom A.

[0039] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0040] (1) The present invention provides a twelve-pole radial magnetic levitation bearing and its magnetic pole configuration control method. The rotor is divided into three ranges according to the maximum working speed: 0-30%, 30%-70%, and 70%-100%. Two, three, and six magnetic pole pairs are used respectively. At low speed, only a few magnetic poles are turned on to reduce power consumption, while at high speed, multiple magnetic poles are selected to ensure load-bearing capacity. This takes into account the requirements of low power consumption and high load-bearing capacity of magnetic levitation bearing, improves the load-bearing capacity of magnetic levitation bearing, and meets the development needs of high efficiency, high performance, and wide working speed range of magnetic levitation rotating machinery.

[0041] (2) The present invention provides a twelve-pole radial magnetic levitation bearing and its magnetic pole configuration control method. The stator magnetic poles are spaced 30° apart and are configured with NSSNNSSNNSSN polarity. The 12 magnetic poles are divided into 6 groups of magnetic pole pairs, and the coils between the 6 groups of magnetic pole pairs are independent of each other. Three 120° distributed control degrees of freedom A, B, and C are designed, and orthogonal displacement sensors are used to detect x and y displacements. The hardware structure is highly matched with the magnetic pole configuration control method, providing hardware support for magnetic pole configuration control.

[0042] (3) The present invention provides a twelve-pole radial magnetic levitation bearing and its magnetic pole configuration control method, which has two electromagnetic force allocation methods: two-control degree of freedom allocation and three-control degree of freedom allocation. The two-control degree of freedom allocation first discards the degree of freedom with the smallest projected length, and performs vector decomposition on the remaining two to adapt to the two-pole pair configuration; the three-control degree of freedom allocation directly allocates all electromagnetic force to the three degrees of freedom A, B, and C to adapt to the three- and six-pole pair configurations. The two electromagnetic force allocation methods ensure that the electromagnetic force required for rotor suspension control can be correctly generated.

[0043] (4) The present invention provides a twelve-pole radial magnetic levitation bearing and its magnetic pole configuration control method. In the zero bias mode, current is passed through only one magnetic pole pair in a single control degree of freedom, which is suitable for two- and three-pole pair configurations. In the constant bias mode, current is passed through both magnetic pole pairs in a single control degree of freedom, which is suitable for six-pole pair configurations. The two magnetic pole current distribution modes can be adapted to different operating speed conditions and optimize current distribution to improve operating efficiency. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of a magnetic pole configuration control method for a twelve-pole radial magnetic levitation bearing according to the present invention;

[0045] Figure 2 This is a schematic diagram of a twelve-pole radial magnetic levitation bearing structure according to the present invention;

[0046] Figure 3 This is a schematic diagram of a specific embodiment of the twelve-pole radial magnetic levitation bearing structure of the present invention;

[0047] Figure 4 This is a schematic diagram of the working mode of the two magnetic pole pairs of the twelve-pole radial magnetic levitation bearing of the present invention;

[0048] Figure 5 This is a schematic diagram of the three-pole configuration working mode of the twelve-pole radial magnetic levitation bearing of the present invention;

[0049] Figure 6 This is a schematic diagram of the six-pole configuration working mode of the twelve-pole radial magnetic levitation bearing of the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] A twelve-pole radial magnetic levitation bearing, characterized in that, as Figure 2 As shown, the stator magnetic poles of the twelve-pole radial magnetic levitation bearing consist of six sets of magnetic pole pairs. Each pair consists of two adjacent magnetic poles, and the coils of each pair are independent. The two magnetic pole coils of each pair are connected in series. The polarity of the magnetic poles is determined by adjusting the coil winding method and the current direction to an NSSNNSSNNSSN polarity configuration. There are two pairs of differentially placed displacement sensors on the stator. The two pairs of displacement sensors are distributed in orthogonal directions and detect the rotor. , Vibration displacement in the direction; such as Figure 3 As shown, the stator magnetic poles are evenly arranged along the circumference, with each pole spaced 30° apart. The resulting six pole pairs are numbered 1, 2, 3, 4, 5, and 6 in a counter-clockwise arrangement. Pole pair 1 is connected to the sensor. The angle between the directions is The six magnetic pole pairs are divided into three control degrees of freedom. Magnetic pole pairs 1 and 4 constitute control degree of freedom A, with the positive direction of control degree of freedom A located at magnetic pole pair 1. Magnetic pole pairs 3 and 6 constitute control degree of freedom B, with the positive direction of control degree of freedom B located at magnetic pole pair 3. Magnetic pole pairs 2 and 5 constitute control degree of freedom C, with the positive direction of control degree of freedom C located at magnetic pole pair 5. Control degrees of freedom A are used as the initial axis, and control degrees of freedom B and C are obtained by rotating counterclockwise along the initial axis. The angle between the positive directions of control degrees of freedom A, B, and C is 120°.

[0052] Specifically, for the aforementioned twelve-pole radial magnetic levitation bearing, the first magnetic pole pair is related to the sensor. Angle of direction Preferably 0°, number of turns of the magnetic pole pair coil Preferably 150 turns, single magnetic pole area Preferably 2×10 -4 m 2 air gap of magnetic levitation bearing Preferably 2.5×10 -4 m, bias current Preferably, it is 1.5A. A specific embodiment of the twelve-pole radial magnetic levitation bearing is as follows: Figure 3 As shown.

[0053] A magnetic pole configuration control method, such as Figure 1As shown, it includes the following steps:

[0054] Step S1: The rotor position information is measured by the displacement sensor, and the electromagnetic force required to be output by the magnetic levitation bearing is calculated by the displacement loop control algorithm;

[0055] Step S2: The electromagnetic force distribution module distributes the electromagnetic force calculated by the displacement loop control algorithm to the three control degrees of freedom, which is divided into two-degree-of-freedom distribution and three-degree-of-freedom distribution.

[0056] Step S3: Magnetic pole current distribution. Based on the results of the electromagnetic force distribution module, the current on each magnetic pole pair is configured, which is divided into constant bias current control mode and zero bias current control mode.

[0057] Step S4: Input the current command after magnetic pole current distribution into the power amplifier, and generate the corresponding current in the coil of the twelve-pole radial magnetic levitation bearing to meet the control requirements.

[0058] Furthermore, the magnetic pole configuration control method is divided into two-pole pair configuration, three-pole pair configuration, and six-pole pair configuration; the two-pole pair configuration indicates the selection of the above-mentioned two-degree-of-freedom electromagnetic force distribution and zero-bias current magnetic pole current distribution, and its magnetic pole current is as follows: Figure 4 As shown, the three-pole pair configuration represents the selection of the above-mentioned three-degree-of-freedom electromagnetic force distribution and zero-bias current magnetic pole current distribution, and its magnetic pole current is as follows. Figure 5 As shown, the six-pole configuration represents the selection of the above-mentioned three-degree-of-freedom electromagnetic force distribution and constant bias current magnetic pole current distribution, and its magnetic pole current is as follows: Figure 6 As shown.

[0059] Furthermore, the magnetic pole configuration control method selects the corresponding magnetic pole pair configuration scheme according to the speed range in which the rotor is located: a two-pole pair configuration is selected in the 0-30% range of the highest operating speed, a three-pole pair configuration is selected in the 30%-70% range of the highest operating speed, and a six-pole pair configuration is selected in the 70%-100% range of the highest operating speed.

[0060] Furthermore, the input signal of the displacement loop control algorithm is obtained by subtracting the output signal of the displacement sensor from the coordinates of the geometric center of the magnetic levitation bearing. Represents rotor Displacement error in the direction, Represents rotor The displacement error in the direction; the output signal of the displacement loop control algorithm is calculated by the PID control algorithm, and the output signal... Represents the control of electromagnetic force on the rotor Components in direction, Represents the control of electromagnetic force on the rotor Components in direction.

[0061] Furthermore, the input signal for the electromagnetic force distribution is the rotor calculated by the displacement loop control algorithm. , The required control electromagnetic force in the direction , The output signal of the electromagnetic force distribution is the control electromagnetic force in the directions of degrees of freedom A, B, and C. , , It is divided into two-degree-of-freedom control allocation and three-degree-of-freedom control allocation.

[0062] Furthermore, regarding the allocation of the two control degrees of freedom, corresponding to the configuration of the two magnetic pole pairs in the magnetic pole configuration control method, the steps are divided into two steps: control degree of freedom selection and electromagnetic force vector decomposition.

[0063] The specific selection of control degrees of freedom is as follows: control the electromagnetic force vector. , Projected onto control degrees of freedom A, B, and C, the projection length is... , , for:

[0064]

[0065] get , , The control degree of freedom with the smallest projection length is selected, and the other two control degrees of freedom are decomposed into electromagnetic force vectors.

[0066] The electromagnetic force vector decomposition is as follows: If A and B are chosen to control the degrees of freedom, the decomposition equation is expressed as:

[0067]

[0068] If we choose B and C to control the degrees of freedom, the decomposition equation can be expressed as:

[0069]

[0070] If A and C are chosen to control the degrees of freedom, the decomposition equation can be expressed as:

[0071] .

[0072] Furthermore, the three-degree-of-freedom control allocation distributes the electromagnetic force to the three control degrees of freedom A, B, and C, corresponding to a three-pole pair configuration and a six-pole pair configuration. The electromagnetic force allocation equation is as follows:

[0073] .

[0074] Furthermore, in the zero-bias current control mode, only one magnetic pole pair is selected for control current flow in one degree of control freedom, corresponding to a two-pole pair configuration or a three-pole pair configuration; for the magnetic pole current distribution in degree of control freedom A, the current flowed through the two magnetic pole pairs in this degree of control freedom is:

[0075]

[0076] in, Indicates the air permeability. Indicates the number of turns of the coil for each magnetic pole pair. Represents the area of ​​a single magnetic pole. Indicates the air gap of the magnetic levitation bearing. This represents the control electromagnetic force assigned to control degree of freedom A. express , The equivalent displacement projected onto control degree of freedom A is expressed as follows:

[0077]

[0078] The magnetic pole current distribution control method on control degrees of freedom B and C is the same as the zero bias current control mode on control degree of freedom A.

[0079] Furthermore, in the constant bias current control mode for the magnetic pole current distribution, current is applied to both magnetic pole pairs in one degree of freedom, corresponding to a six-pole pair configuration; for the magnetic pole current distribution in degree of freedom A, the current applied to the two magnetic pole pairs in this degree of freedom is:

[0080]

[0081] in, Indicates the bias current. This represents the control electromagnetic force assigned to control degree of freedom A. express , The equivalent displacement projected onto the control degree of freedom A. Indicates the current stiffness value. The values ​​represent displacement stiffness, and their expressions are as follows:

[0082]

[0083] in, Indicates the air permeability. Indicates the number of turns of the coil for each magnetic pole pair. Represents the area of ​​a single magnetic pole. The air gap of the magnetic levitation bearing is indicated; the magnetic pole current distribution control method on the control degrees of freedom B and C is the same as the constant bias current control mode on the control degree of freedom A.

[0084] Those skilled in the art should understand that, unless otherwise specified, the meanings of the technical and scientific terms used herein are consistent with the general understanding of the relevant technical field. Furthermore, terms defined in general dictionaries should be understood in the context of the technical background in this field and should not be interpreted in an overly idealized or formalistic manner divorced from practical application scenarios.

[0085] The above embodiments have described in detail the main concept, technical solution, and technical effects of the present invention. It should be noted that the above content is merely illustrative and not intended to limit the scope of protection of the present invention. Any equivalent modifications, substitutions, or optimizations based on the present invention without departing from its core principles are within the scope of the present invention.

Claims

1. A twelve-pole radial magnetic levitation bearing, characterized in that, The stator magnetic poles of the twelve-pole radial magnetic levitation bearing consist of six sets of pole pairs, with each pair consisting of two adjacent poles. The coils of each pole pair are independent, and the two pole coils of each set are connected in series. The pole polarity is determined by adjusting the coil winding method and the current direction to achieve an NSSNNSSNNSSN polarity configuration. The stator has two pairs of differentially placed displacement sensors, distributed orthogonally, which detect the rotor. , The vibration displacement in the direction; the stator magnetic poles are evenly arranged along the circumference, with an angle of 30° between each magnetic pole, forming 6 magnetic pole pairs arranged counterclockwise and numbered 1, 2, 3, 4, 5, and 6 respectively, where magnetic pole pair 1 is connected to the sensor. The angle between the directions is ; The six magnetic pole pairs are divided into three control degrees of freedom. Magnetic pole pairs 1 and 4 constitute control degree of freedom A, with the positive direction of control degree of freedom A located at magnetic pole pair 1. Magnetic pole pairs 3 and 6 constitute control degree of freedom B, with the positive direction of control degree of freedom B located at magnetic pole pair 3. Magnetic pole pairs 2 and 5 constitute control degree of freedom C, with the positive direction of control degree of freedom C located at magnetic pole pair 5. Control degrees of freedom A are used as the initial axis, and control degrees of freedom B and C are obtained by rotating counterclockwise along the initial axis. The angle between the positive directions of control degrees of freedom A, B, and C is 120°.

2. A method for controlling magnetic pole configuration, characterized in that, The magnetic pole configuration control method is applicable to a twelve-pole radial magnetic levitation bearing as described in claim 1, and the magnetic pole configuration control method includes the following steps: Step S1: The rotor position information is measured by the displacement sensor, and the electromagnetic force required to be output by the magnetic levitation bearing is calculated by the displacement loop control algorithm; Step S2: The electromagnetic force distribution module distributes the electromagnetic force calculated by the displacement loop control algorithm to the three control degrees of freedom, which is divided into two-degree-of-freedom distribution and three-degree-of-freedom distribution. Step S3: Magnetic pole current distribution. Based on the results of the electromagnetic force distribution module, the current on each magnetic pole pair is configured, which is divided into constant bias current control mode and zero bias current control mode. Step S4: Input the current command after magnetic pole current distribution into the power amplifier, and generate the corresponding current in the coil of the twelve-pole radial magnetic levitation bearing to meet the control requirements.

3. The magnetic pole configuration control method according to claim 2, characterized in that, The magnetic pole configuration control method is divided into two-pole pair configuration, three-pole pair configuration, and six-pole pair configuration. The two-pole pair configuration means selecting the above-mentioned two-degree-of-freedom electromagnetic force distribution and zero-bias current magnetic pole current distribution. The three-pole pair configuration means selecting the above-mentioned three-degree-of-freedom electromagnetic force distribution and zero-bias current magnetic pole current distribution. The six-pole pair configuration means selecting the above-mentioned three-degree-of-freedom electromagnetic force distribution and constant-bias current magnetic pole current distribution.

4. The magnetic pole configuration control method according to claim 3, characterized in that, The magnetic pole configuration control method selects the corresponding magnetic pole pair configuration scheme according to the speed range in which the rotor is located: a two-pole pair configuration is selected in the 0-30% range of the highest operating speed, a three-pole pair configuration is selected in the 30%-70% range of the highest operating speed, and a six-pole pair configuration is selected in the 70%-100% range of the highest operating speed.

5. The magnetic pole configuration control method according to claim 4, characterized in that, The input signal of the displacement loop control algorithm is obtained by subtracting the output signal of the displacement sensor from the coordinates of the geometric center of the magnetic levitation bearing. Represents rotor Displacement error in the direction, Represents rotor Displacement error in the direction; The output signal of the displacement loop control algorithm is calculated by the PID control algorithm. Represents the control of electromagnetic force on the rotor Components in direction, Represents the control of electromagnetic force on the rotor Components in direction.

6. The magnetic pole configuration control method according to claim 5, characterized in that, The input signal for electromagnetic force distribution is the rotor calculated by the displacement loop control algorithm. , The required control electromagnetic force in the direction , The output signal of the electromagnetic force distribution is the control electromagnetic force in the directions of degrees of freedom A, B, and C. , , It is divided into two-degree-of-freedom control allocation and three-degree-of-freedom control allocation.

7. The magnetic pole configuration control method according to claim 6, characterized in that, For the allocation of the two control degrees of freedom, corresponding to the configuration of the two magnetic pole pairs in the magnetic pole configuration control method, the steps are divided into two steps: control degree of freedom selection and electromagnetic force vector decomposition. The specific selection of control degrees of freedom is as follows: control the electromagnetic force vector. , Projected onto control degrees of freedom A, B, and C, the projection length is... , , for: get , , The control degree of freedom with the smallest projection length is selected, and the other two control degrees of freedom are decomposed into electromagnetic force vectors. The electromagnetic force vector decomposition is as follows: If A and B are chosen to control the degrees of freedom, the decomposition equation is expressed as: If we choose B and C to control the degrees of freedom, the decomposition equation can be expressed as: If A and C are chosen to control the degrees of freedom, the decomposition equation can be expressed as: 。 8. The magnetic pole configuration control method according to claim 7, characterized in that, The three-degree-of-freedom allocation distributes the electromagnetic force to the three control degrees of freedom, A, B, and C, corresponding to a three-pole pair configuration and a six-pole pair configuration. The electromagnetic force allocation equation is as follows: 。 9. A magnetic pole configuration control method according to claim 8, characterized in that, The zero-bias current control mode selects only one magnetic pole pair to apply control current in one degree of control freedom, corresponding to a two-pole pair configuration or a three-pole pair configuration; for the magnetic pole current distribution of control degree of freedom A, the current applied to the two magnetic pole pairs in this degree of control freedom is: in, Indicates the air permeability. Indicates the number of turns of the coil for each magnetic pole pair. Represents the area of ​​a single magnetic pole. Indicates the air gap of the magnetic levitation bearing. This represents the control electromagnetic force assigned to control degree of freedom A. express , The equivalent displacement projected onto control degree of freedom A is expressed as follows: The magnetic pole current distribution control method on control degrees of freedom B and C is the same as the zero bias current control mode on control degree of freedom A.

10. A magnetic pole configuration control method according to claim 9, characterized in that, The constant bias current control mode for the magnetic pole current distribution involves applying current to both magnetic pole pairs in one degree of freedom, corresponding to a six-pole pair configuration. For the magnetic pole current distribution in degree of freedom A, the current applied to the two magnetic pole pairs in that degree of freedom is: in, Indicates the bias current. This represents the control electromagnetic force assigned to control degree of freedom A. express , The equivalent displacement projected onto the control degree of freedom A. Indicates the current stiffness value. The values ​​represent displacement stiffness, and their expressions are as follows: in, Indicates the air permeability. Indicates the number of turns of the coil for each magnetic pole pair. Represents the area of ​​a single magnetic pole. The air gap of the magnetic levitation bearing is indicated; the magnetic pole current distribution control method on the control degrees of freedom B and C is the same as the constant bias current control mode on the control degree of freedom A.

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