Improved bearingless doubly salient electro-magnetic machine with integrated winding structure

Abstract

This invention discloses an improved integrated winding structure for a bearingless electrically excited doubly salient pole motor, relating to the field of bearingless motor technology. It integrates the levitation winding and excitation winding of a traditional bearingless electrically excited doubly salient pole motor into an integrated levitation winding. A control method is provided to enable the integrated winding configuration of the bearingless electrically excited doubly salient pole motor for power generation and stable levitation. This control method includes a displacement control module, a levitation current calculation module, and a levitation current control module. Stable rotor levitation can be achieved by controlling the levitation winding current. This scheme optimizes the winding arrangement and achieves mutual scheduling of power generation and levitation capabilities through equivalent control. Compared to traditional bearingless doubly salient pole motors, the integrated winding configuration bearingless electrically excited doubly salient pole motor designed in this invention improves the utilization rate of slot space, expands the working range of the bearingless doubly salient pole motor, and its overall operating state is more flexible.

Description

Technical Field

[0001] This invention relates to the technical field of bearingless electrically excited doubly salient pole motors, and more particularly to a bearingless electrically excited doubly salient pole motor with an improved integrated winding structure. Background Technology

[0002] The stator and rotor of an electrically excited doubly salient pole motor are both salient pole structures. The motor's excitation magnetic field is provided by DC excitation current. During power generation, no controllable rectifier devices or angle position sensors are required, resulting in a simple, robust, and easy-to-maintain structure with excellent adaptability to high-temperature environments and high-speed operation. To avoid heat generation and wear of the motor's mechanical bearings under high-speed operation, magnetic bearings are gradually being used as replacements, allowing the motor to maintain normal operation without contact between the stator and rotor. However, achieving stable levitation rotation in a magnetic bearing motor requires numerous power devices, making control difficult, and resulting in complex structures, high costs, and low power density. Bearingless motors are a new type of motor that integrates the functions of magnetic bearings with drive or power generation functions, featuring compact structure and high space utilization. For example, current electromagnetic bearingless doubly salient pole motors and their control methods utilize the superposition of the excitation magnetic field generated by the excitation winding and the levitation magnetic field generated by the levitation winding, resulting in a difference in the air gap magnetic flux density on both sides of the stator, thus achieving stable rotor levitation.

[0003] The superposition of the excitation magnetic field generated by the excitation winding and the levitation magnetic field generated by the levitation winding in the motor results in a difference in the air gap magnetic flux density on both sides of the stator, thus achieving stable rotor levitation. Once the motor is in a stable operating state, only a small levitation current needs to be applied to the levitation winding to counteract the rotor's gravity, thereby maintaining stable rotor levitation. At this point, the levitation winding only outputs a small levitation force and cannot output power, thus wasting winding resources. In traditional bearingless electrically excited doubly salient pole motors, the excitation winding and the two sets of levitation windings need to be controlled independently. Furthermore, once the motor's winding structure is determined, the levitation winding and excitation winding cannot be reconfigured, preventing more rational configuration adjustments and flexible switching and scheduling. This limits the motor's power generation and levitation force output capabilities to some extent. This leads to the current bearingless electrically excited doubly salient pole motor design where the excitation winding and levitation winding need to be controlled independently, and once the motor's winding structure is determined, flexible switching and scheduling of the excitation winding and levitation winding cannot be achieved, limiting the motor's power generation and levitation force output capabilities.

[0004] Therefore, how to further integrate and optimize the levitation winding and the excitation winding has become a research topic. Summary of the Invention

[0005] The embodiments of the present invention provide a bearingless electrically excited doubly salient pole motor with an improved integrated winding structure, which can broaden the operating range of the bearingless doubly salient pole motor.

[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0007] In a first aspect, the improved integrated winding structure of the bearingless electrically excited doubly salient pole motor provided by embodiments of the present invention includes: a rotor core, a stator core, an armature winding, and a suspension winding, wherein the suspension winding includes, as shown in the figure below. Figure 1 The No. 1 suspension winding W shown sf1 #2 suspension winding W sf2 #3 suspension winding W sf3 and #4 suspension winding W sf4 ;

[0008] The armature coils wound on the stator poles are connected according to the principle that the change in magnetic flux of the turns is the same, forming the armature winding W. m ;

[0009] Armature coils of the same phase are connected in series to form the armature winding of the phase. Each phase armature winding has two terminals and is connected to the external control circuit shown in Figure 5(a) through these two terminals.

[0010] A radial suspension winding is embedded on every three stator poles. The current of each suspension winding is individually controlled, and each suspension winding is connected to a separate control circuit. The suspension windings do not interfere with each other. If the current is defined as flowing in from the first terminal and out from the second terminal of the suspension winding as the positive reference direction, then the equivalent magnetic poles formed on the outside of the rotor core are arranged in a clockwise NSNS pattern. According to the right-hand screw rule, the winding arrangement is designed, and a current in a specified direction is applied so that the equivalent magnetic poles formed by the four windings on the outside of the rotor core are arranged in a clockwise NSNS pattern. Furthermore, the #1 suspension winding W... sf1 The windings are wound in slots ① and ②, with the windings entering from slot ① and exiting from slot ②, surrounding stator poles A1, B1, and C1 around W. sf1 Internal; #2 suspension winding W sf2 The windings are wound in slots ① and ③, with the winding entering from slot ③ and exiting from slot ①, surrounding stator poles A2, B2, and C2 around W. sf2 Internal; #3 suspension winding W sf3 The windings are wound in slots ③ and ④, with the windings entering from slot ③ and exiting from slot ④, surrounding stator poles A3, B3, and C3 around W. sf3 Internal; #4 suspension winding W sf4 The windings are wound in slots ② and ④, with the windings entering from slot ② and exiting from slot ④, surrounding stator poles A4, B4, and C4 around W. sf4 internal.

[0011] In a preferred embodiment, the bearingless electrically excited doubly salient pole motor adopts a 12 / 8-pole doubly salient pole structure; wherein, the rotor core is a salient pole structure, composed of toothed core laminations, with a total of 8 rotor poles; the stator core is also a salient pole structure, with a total of 12 stator poles, and the gaps between adjacent stator poles form stator slots; the suspension winding W sf There are 4 groups in total. One axial armature coil N is wound on each stator pole. m And the three adjacent stator poles are grouped together, resulting in a total of 4 groups of armature coils N. m In each group, there are three armature coils N m The armature coils N in each group belong to phases A, B, and C respectively. m The armature winding W that makes up this phase m .

[0012] Figure 5(a) is a schematic diagram of the external rectifier circuit of the bearingless electrically excited doubly salient pole motor with integrated winding configuration according to an embodiment of the present invention. A full-bridge uncontrolled rectifier circuit is used to rectify the AC current generated on the three-phase armature windings: the first rectifier diode D1 and the second rectifier diode D2 are connected in series, the third rectifier diode D3 and the fourth rectifier diode D4 are connected in series, and the fifth rectifier diode D5 and the sixth rectifier diode D6 are connected in series. The cathodes of the first rectifier diode D1, the third rectifier diode D3, and the fifth rectifier diode D5 are connected, and the anodes of the second rectifier diode D2, the fourth rectifier diode D4, and the sixth rectifier diode D6 are connected. mA L mB L mC The input terminals of the three-phase armature windings are connected, L mA L mB L mC The output terminals of the three-phase windings are connected to the anodes of the first rectifier diode D1, the second rectifier diode D2, and the third rectifier diode D3, respectively. The capacitor C and resistor R are connected in parallel, with their two ends connected to the common cathode and common anode of the diodes, respectively.

[0013] The control circuits connected to the four sets of suspended excitation windings are as follows: The control circuit for the first set of suspended excitation windings includes: a first MOS switch Q1 and a second MOS switch Q2 connected in series, a third MOS switch Q3 and a fourth MOS switch Q4 connected in series, the drains of the first MOS switch Q1 and the third MOS switch Q3 connected to the positive terminal of the DC voltage source Us, and the sources of the second MOS switch Q2 and the fourth MOS switch Q4 connected to the negative terminal of the DC voltage source Us. The suspended excitation winding W... sf1The equivalent Lsf1 and the two ends of resistor R1 are connected to the source of the first MOS switch Q1 and the source of the third MOS switch Q3. Electrolytic capacitor C1 is connected in parallel across the voltage source Us. The control circuit for the second set of suspended windings includes: the fifth MOS switch Q5 and the sixth MOS switch Q6 are connected in series, the seventh MOS switch Q7 and the eighth MOS switch Q8 are connected in series, the drain of the fifth MOS switch Q5 and the drain of the seventh MOS switch Q7 are connected to the positive terminal of the DC voltage source Us, and the source of the sixth MOS switch Q6 and the source of the eighth MOS switch Q8 are connected to the negative terminal of the DC voltage source Us. The suspended winding W sf2 The equivalent Lsf2 and resistor R2 are connected to the source of the fifth MOS switch Q5 and the source of the seventh MOS switch Q7. Electrolytic capacitor C2 is connected in parallel across the voltage source Us. The control circuit for the third set of suspended windings includes: the ninth MOS switch Q9 and the tenth MOS switch Q10 connected in series, the eleventh MOS switch Q11 and the twelfth MOS switch Q12 connected in series, the drain of the ninth MOS switch Q9 and the drain of the eleventh MOS switch Q11 connected to the positive terminal of the DC voltage source Us, and the source of the tenth MOS switch Q10 and the source of the twelfth MOS switch Q12 connected to the negative terminal of the DC voltage source Us. The suspended winding W... sf3 The equivalent Lsf3 and resistor R3 are connected to the source of the ninth MOS switch Q9 and the eleventh MOS switch Q11. Electrolytic capacitor C3 is connected in parallel across the voltage source Us. The control circuit for the fourth set of suspended windings includes: the thirteenth MOS switch Q13 and the fourteenth MOS switch Q14 connected in series; the fifteenth MOS switch Q15 and the sixteenth MOS switch Q16 connected in series; the drain of the thirteenth MOS switch Q13 and the drain of the fifteenth MOS switch Q3 are connected to the positive terminal of the DC voltage source Us; the source of the fourteenth MOS switch Q14 and the source of the sixteenth MOS switch Q16 are connected to the negative terminal of the DC voltage source Us; and the suspended winding W... sf4 The equivalent Lsf4 and resistor R4 are connected to the source of the thirteenth MOS switch Q13 and the source of the fifteenth MOS switch Q15, respectively, and electrolytic capacitor C4 is connected in parallel across the voltage source Us.

[0014] Secondly, the control method provided by the embodiments of the present invention includes: a displacement control module, a suspension current calculation module, and a suspension current control module;

[0015] The displacement control module acquires reference values ​​of the levitation current in the X and Y directions;

[0016] In the suspension current calculation module, the given values ​​of the suspension current in the suspension windings in the X and Y directions are obtained based on the suspension current reference values ​​in the X and Y directions.

[0017] In the suspension current control module, the difference between the actual current value of each suspension winding and the given value of the suspension current of each suspension winding obtained by the suspension current calculation step is input into the PI link corresponding to each suspension winding.

[0018] The four PWM signals output by the suspended excitation current control module are respectively input into the corresponding modules. The four suspended excitation current control modules control the switching of their respective switching transistors according to their respective PWM signals to achieve the tracking of the suspended excitation current to its reference value.

[0019] The displacement control includes: using an eddy current sensor to obtain the rotor's current position x and a rotor position reference value x. * After subtraction and adjustment by the X-axis displacement PID control module, the required levitation force F in the X-axis direction is obtained. x * The rotor position angle, armature current, and suspension current obtained from the sampling are transformed using coordinates to obtain the reference value of the suspension current i. sx * The rotor's current position y and the rotor position reference value y are obtained using an eddy current sensor. * After subtraction and adjustment by the Y-axis displacement PID control module, the required levitation force F in the Y-axis direction is obtained. y * The rotor position angle, armature current, and suspension current obtained from the sampling are transformed using coordinates to obtain the suspension current reference value i. sy * .

[0020] The calculation of the suspension current includes: the reference value i of the required suspension current in the Y-axis direction. sy * The reference value of excitation current required under this operating condition i f * After performing the addition operation, we obtain the W of the #1 suspension winding. sf1 The current flowing through it, i is the given value of the suspension current. sf1 * The required levitation current reference value i in the X-axis direction sx * The reference value of excitation current required under this operating condition i f * After performing the addition operation, we obtain the #2 suspension winding W. sf2 The current flowing through it, i is the given value of the suspension current. sf2 * The required levitation current reference value i in the Y-axis direction sy * The reference value of excitation current required under this operating condition, i f *After subtraction, we obtain the W of the #3 suspension winding. sf3 The current flowing through it, i is the given value of the suspension current. sf3 * The required levitation current reference value i in the X-axis direction sx * The reference value of excitation current required under this operating condition, i f * After subtraction, we obtain the W of the #4 suspension winding. sf4 The current flowing through it, i is the given value of the suspension current. sf4 * .

[0021] The suspension current control includes: controlling the W winding of the #1 suspension winding. sf1 The actual current i passing through it sf1 The given value i of the corresponding suspension current sf1 * The difference value is input into the corresponding PI circuit, and the W of the #2 suspension winding is... sf2 The actual current i passing through it sf2 The given value i of the corresponding suspension current sf2 * Input the difference value into the corresponding PI circuit, and input the W value of the #3 suspension winding. sf3 The actual current i passing through it sf3 The given value i of the corresponding suspension current sf3 * Input the difference value into the corresponding PI circuit, and input the W value of the #4 suspension winding. sf4 The actual current i passing through it sf4 The given value i of the corresponding suspension current sf4 * The difference value is input into the corresponding PI circuit. The suspended excitation current control module includes: in the displacement control module, four sets of eddy current sensors are used to obtain the rotor position signal by measuring the distance between the probe and the reference ring of the rotating shaft; in the suspended excitation current control section, four sets of current Hall sensors are used to measure the current flowing through the four sets of suspended excitation windings respectively.

[0022] The improved integrated winding structure of the bearingless electrically excited doubly salient pole motor provided in this invention improves upon the original bearingless electrically excited doubly salient pole motor by modifying the suspension winding and excitation winding, integrating them into a single suspended winding. Compared to traditional bearingless doubly salient pole motors, the integrated winding bearingless electrically excited doubly salient pole motor designed in this invention improves the utilization rate of slot space, expands the working range of the bearingless doubly salient pole motor, and offers greater overall flexibility in its operation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is an overall structural diagram of a bearingless electrically excited doubly salient pole motor with integrated winding configuration according to an embodiment of the present invention.

[0025] Figure 2 A schematic diagram of the structure and winding arrangement of an integrated winding configuration bearingless electrically excited doubly salient pole motor according to an embodiment of the present invention;

[0026] Figure 3 Equivalent magnetic circuit diagram of a bearingless electrically excited doubly salient pole motor with integrated winding configuration according to an embodiment of the present invention;

[0027] Figure 4 A schematic diagram of the electromagnetic forces generated by each stator pole of a bearingless electrically excited doubly salient pole motor with integrated winding configuration according to an embodiment of the present invention.

[0028] Figures 5(a) to 5(e) These are schematic diagrams of the external rectifier circuit and the four sets of suspension winding control circuits for an integrated winding configuration bearingless electrically excited double salient pole motor according to an embodiment of the present invention.

[0029] Figure 6 This is a flowchart illustrating the drive control of a bearingless electrically excited doubly salient pole motor that provides power output and levitation force according to an embodiment of the present invention.

[0030] Figure 7 This is a comparison chart of the operating ranges of an integrated winding-configured bearingless electrically excited doubly salient pole motor (IWBDSEM) under equivalent control and a bearingless electrically excited doubly salient pole motor (BDSEM) with variable excitation windings and suspension windings. In the comparison chart: ω=4000r / min, R load =2Ω. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Embodiments of the present invention will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in the specification of the present invention means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or couplings. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0032] The general structural features of the electromagnetic bearingless double salient pole motor designed in this embodiment are as follows: Figure 1 The three-phase 12 / 8 structure electromagnetic bearingless doubly salient pole motor shown is only one embodiment of the present invention. The technical solution of the present invention is also applicable to the three-phase structure of 12n / 4n or the four-phase structure of 16n / 6n, where n is a positive integer.

[0033] Figure 2 This diagram illustrates the structure and winding arrangement of the integrated winding configuration bearingless electrically excited double salient pole motor of the present invention. The integrated winding configuration bearingless electrically excited double salient pole motor adopts a 12 / 8-pole double salient pole structure with high power density among the double salient pole structures with pole slot matching currently under research theory. It includes: a rotor core, a stator core, an armature winding, and a suspension winding. The rotor core is composed of toothed core laminations and has 8 rotor poles. The stator core is also a salient pole structure with 12 stator poles. The gaps between adjacent stator poles form stator slots. Furthermore, in this embodiment, "winding" is uniformly identified as "W", such as the armature winding "W". m; and uniformly label "coil" as "N", such as armature coil "N" m "To distinguish them."

[0034] Figure 2 This is a schematic diagram of the structure and winding arrangement of a bearingless electrically excited doubly salient pole motor with integrated winding configuration according to an embodiment of the present invention. The armature coils wound on the stator poles are arranged according to the principle that the change in magnetic flux through the turns is the same, and the armature coils of the same phase are arranged according to... Figure 2 The wiring diagram shown represents the armature windings of that phase connected in series. In the three-phase armature windings, each phase has two terminals, which are connected to the external control circuit via these two terminals, resulting in a total of six terminals across the three phases. One armature coil N is wound on each stator pole. m The three adjacent stator poles are grouped together, resulting in four groups in total. The first terminal A+ and the second terminal A- of the A-phase armature winding are connected to the external control circuit. Similarly, the first terminal B+ and the second terminal B- of the B-phase armature winding are connected to the external control circuit; the first terminal C+ and the second terminal C- of the C-phase armature winding are also connected to the external control circuit. Each set of three stator poles is wound with a radial suspension winding, the current of which is individually controlled. Each set of suspension windings does not interfere with each other, resulting in four sets, all wound in the same manner. If the current flowing into the suspension winding from the first terminal and out from the second terminal is defined as the positive reference direction, then the equivalent magnetic poles formed on the outside of the rotor core are arranged in a clockwise direction in an NSNS pattern. Among them, the #1 suspension winding W... sf1 The windings are wound in slots ① and ②, with the windings entering from slot ① and exiting from slot ②, surrounding stator poles A1, B1, and C1 around W. sf1 Internal; #2 suspension winding W sf2 The windings are wound in slots ① and ③, with the winding entering from slot ③ and exiting from slot ①, surrounding stator poles A2, B2, and C2 around W. sf2 Internal; #3 suspension winding W sf3 The windings are wound in slots ③ and ④, with the windings entering from slot ③ and exiting from slot ④, surrounding stator poles A3, B3, and C3 around W. sf3 Internal; #4 suspension winding W sf4 The windings are wound in slots ② and ④, with the windings entering from slot ② and exiting from slot ④, surrounding stator poles A4, B4, and C4 around W. sf4 internal.

[0035] Figure 3 This is the equivalent magnetic circuit diagram of an integrated winding bearingless electrically excited doubly salient pole motor according to an embodiment of the present invention. Where i mA i mB i mCThese represent the current values ​​flowing through the armature windings of phases A, B, and C, respectively. sf1 i sf2 i sf3 i sf4 These represent the currents flowing through the four suspension windings: right, top, left, and bottom. N m N is the number of turns in the armature winding. sf Let be the number of turns of the four suspended windings. Ignoring the effects of nonlinear factors such as core magnetic saturation and leakage flux, the equations of the equivalent magnetic circuit can be written based on the equivalent magnetic circuit diagram, as shown in equation (1):

[0036]

[0037] Let the outer surface of the rotor be the zero magnetic potential surface. In the above equation, M1, M2, M3, and M4 are the magnetomotive forces of the four nodes, which are independent of the rotor position angle. The solution is shown in equation (2):

[0038]

[0039] The calculated magnetic flux density at each stator pole is shown in equation (3) below, where j is A, B, or C, μ0 is the free permeability, and L gap For air gap length:

[0040]

[0041] Figure 4 This is a schematic diagram illustrating the electromagnetic forces generated by each stator pole of a bearingless electrically excited doubly salient pole motor with integrated winding configuration according to an embodiment of the present invention. The example is taken during operation when the rotor angle is between 0° and 15° and phases A and B overlap. The electromagnetic force vector F generated by each stator pole is... jk The direction is considered to be from the center of the rotor to the center of the stator pole, and k is the number of stator pole group 1 to 4. The magnitude of the electromagnetic force generated by each stator pole on the rotor can be calculated by Maxwell's stress method:

[0042]

[0043] Among them, S j Let J be the overlap area between the stator pole and the rotor pole of phase j, as shown in equation (5):

[0044]

[0045] The calculation results are shown in equation (6):

[0046]

[0047] Among them, F A1-3 F represents A1 With F A3 The magnitude of the resultant force, FA2-4 F represents A2 With F A4 The magnitude of the resultant force, F B1-3 It refers to F B1 With F B3 The magnitude of the resultant force, F B2-4 It refers to F B2 With F B4 The magnitude of the resultant force. F x and F y Let F be the components of the levitation force vector F acting on the rotor in the X-axis and Y-axis directions, respectively, as shown in equation (7):

[0048]

[0049] Substituting equation (6) into equation (7), the magnitudes of the components of the levitation force vector F acting on the rotor in the X-axis and Y-axis directions can be obtained through calculation. The calculation results are shown in equation (8).

[0050]

[0051] Figure 5(a) is a schematic diagram of the external rectifier circuit of the bearingless electrically excited doubly salient pole motor with integrated winding configuration according to an embodiment of the present invention. A full-bridge uncontrolled rectifier circuit is used to rectify the AC current generated on the three-phase armature windings: the first rectifier diode D1 and the second rectifier diode D2 are connected in series, the third rectifier diode D3 and the fourth rectifier diode D4 are connected in series, and the fifth rectifier diode D5 and the sixth rectifier diode D6 are connected in series. The cathodes of the first rectifier diode D1, the third rectifier diode D3, and the fifth rectifier diode D5 are connected, and the anodes of the second rectifier diode D2, the fourth rectifier diode D4, and the sixth rectifier diode D6 are connected. mA L mB L mC The input terminals of the three-phase armature windings are connected, L mA L mB L mC The output terminals of the three-phase windings are connected to the anodes of the first rectifier diode D1, the second rectifier diode D2, and the third rectifier diode D3, respectively. The capacitor C and resistor R are connected in parallel, with their two ends connected to the common cathode and common anode of the diodes, respectively.

[0052] Figure 5(b) is a schematic diagram of the control circuit for the first set of suspended excitation windings. The first MOS switch Q1 and the second MOS switch Q2 are connected in series, and the third MOS switch Q3 and the fourth MOS switch Q4 are connected in series. The drains of the first MOS switch Q1 and the third MOS switch Q3 are connected to the positive terminal of the DC voltage source Us, and the sources of the second MOS switch Q2 and the fourth MOS switch Q4 are connected to the negative terminal of the DC voltage source Us. The suspended excitation winding W... sf1The equivalent Lsf1 and resistor R1 are connected to the source of the first MOS switch Q1 and the source of the third MOS switch Q3, and the electrolytic capacitor C1 is connected in parallel across the voltage source Us.

[0053] Figure 5(c) is a schematic diagram of the control circuit for the second set of suspended excitation windings. The fifth MOS switch Q5 and the sixth MOS switch Q6 are connected in series, and the seventh MOS switch Q7 and the eighth MOS switch Q8 are connected in series. The drains of the fifth MOS switch Q5 and the seventh MOS switch Q7 are connected to the positive terminal of the DC voltage source Us, and the sources of the sixth MOS switch Q6 and the eighth MOS switch Q8 are connected to the negative terminal of the DC voltage source Us. The suspended excitation winding W... sf2 The equivalent Lsf2 and resistor R2 are connected to the source of the fifth MOS switch Q5 and the source of the seventh MOS switch Q7, and the electrolytic capacitor C2 is connected in parallel across the voltage source Us.

[0054] Figure 5(d) is a schematic diagram of the control circuit for the third set of suspended excitation windings. The ninth MOS switch Q9 and the tenth MOS switch Q10 are connected in series, and the eleventh MOS switch Q11 and the twelfth MOS switch Q12 are connected in series. The drains of the ninth MOS switch Q9 and the eleventh MOS switch Q11 are connected to the positive terminal of the DC voltage source Us, and the sources of the tenth MOS switch Q10 and the twelfth MOS switch Q12 are connected to the negative terminal of the DC voltage source Us. The suspended excitation winding W... sf3 The equivalent Lsf3 and resistor R3 are connected to the source of the ninth MOS switch Q9 and the source of the eleventh MOS switch Q11, and the electrolytic capacitor C3 is connected in parallel across the voltage source Us.

[0055] Figure 5(e) is a schematic diagram of the control circuit for the fourth set of suspended excitation windings. The thirteenth MOS switch Q13 and the fourteenth MOS switch Q14 are connected in series, and the fifteenth MOS switch Q15 and the sixteenth MOS switch Q16 are connected in series. The drains of the thirteenth MOS switch Q13 and the fifteenth MOS switch Q14 are connected to the positive terminal of the DC voltage source Us, and the sources of the fourteenth MOS switch Q14 and the sixteenth MOS switch Q16 are connected to the negative terminal of the DC voltage source Us. The suspended excitation winding W... sf4 The equivalent Lsf4 and resistor R4 are connected to the source of the thirteenth MOS switch Q13 and the source of the fifteenth MOS switch Q15 respectively, and the electrolytic capacitor C4 is connected in parallel across the voltage source Us.

[0056] Figure 6This is a flowchart illustrating the drive control of a bearingless electrically excited doubly salient pole motor that provides power output and levitation force according to an embodiment of the present invention. The control method for a bearingless electrically excited doubly salient pole motor with integrated winding configuration is characterized by comprising a displacement control module, a levitation current calculation module, and a levitation current control module. The control steps are as follows: In the displacement control module, the current rotor position x and the rotor position reference value x are obtained using an eddy current sensor. * After subtraction and adjustment by the X-axis displacement PID controller, the required suspension force F in the X-axis direction is obtained. x * F x * The rotor position angle, armature current, and suspension current obtained from the same sampling are transformed to obtain the reference value of the suspension current i. sx * The rotor's current position y and the rotor position reference value y are obtained using an eddy current sensor. * After subtraction and adjustment by the Y-axis displacement PID controller, the required levitation force F in the Y-axis direction is obtained. y * F y * The rotor position angle, armature current, and suspension current obtained from the same sampling are transformed into the reference value of the suspension current i. sy * The required levitation current reference value i in the Y-axis direction. sy * The reference value of excitation current required under this operating condition, i f * After performing the addition operation, the current flowing through the #1 suspension winding, i, is obtained, which is the given value of the suspension current i. sf1 * The required levitation current reference value i in the X-axis direction sx * The reference value of excitation current required under this operating condition, i f * After performing the addition operation, the current flowing through the #2 suspension winding, i, is obtained, which is the given value of the suspension current i. sf2 * The required levitation current reference value i in the Y-axis direction sy * The reference value of excitation current required under this operating condition, i f * The difference is used to obtain the current flowing through the #3 suspension winding, which is the given value i of the suspension current. sf3 * The required levitation current reference value i in the X-axis direction sx * The reference value of excitation current required under this operating condition, i f* After subtraction, the current flowing through the #4 suspension winding, i, is obtained, which is the given value of the suspension current. sf4 * In the suspension current control module, the actual current i passing through the #1 suspension winding is controlled. sf1 The given value i of the corresponding suspension current sf1 * The difference value is input into the corresponding PI circuit to input the actual current i passing through the #2 suspension winding. sf2 The given value i of the corresponding suspension current sf2 * The difference value is input into the corresponding PI circuit to input the actual current i passing through the #3 suspension winding. sf3 The given value i of the corresponding suspension current sf3 * The difference value is input into the corresponding PI circuit to input the actual current i passing through the #4 suspension winding. sf4 The given value i of the corresponding suspension current sf4 * The difference value is input into the corresponding PI circuit. The four PWM signals output from the suspended excitation current control module are input into their respective modules. The four suspended excitation current control modules control the switching on and off of their respective switching transistors according to their respective duty cycle signals to achieve tracking of the suspended excitation current to its reference value.

[0057] Figure 7 A comparison of the operating ranges of an integrated winding-configured bearingless electrically excited doubly salient pole motor (IWBDSEM) under equivalent control and a bearingless electrically excited doubly salient pole motor (BDSEM) with variable excitation windings and suspension windings (ω=4000r / min, R load =2Ω). By changing the turns ratio of the levitation coil and the excitation coil, and replacing the same magnitude of excitation magnetomotive force with levitation magnetomotive force, the correlation between power generation and levitation force under different turns ratios of the levitation coil and the excitation coil was investigated. When the turns ratio of the levitation coil and the excitation coil is 10 / 90, its operating range is... Figure 7 ①, ②, and ③; when the turns ratio of the levitation coil and the excitation coil is 30 / 70, its operating range is... Figure 7 ①, ②, ④, and ⑤; when the turns ratio of the levitation coil and the excitation coil is 50 / 50, its operating range is... Figure 7 ①, ④, and ⑥ in the text. The operating range of the bearingless electrically excited bisalient pole motor with integrated winding configuration under equivalent control is... Figure 7The largest envelope area covers all the above operating ranges, expanding the working range of the bearingless doubly salient pole motor. When the motor requires a larger levitation force output, the levitation current component in the winding can be increased. When the rotor enters a stable levitation state, more excitation current component can be supplied for power generation. Compared to the structure of excitation winding plus levitation winding, this control method eliminates the fixed winding turn allocation, thereby eliminating the problem of the inability to coordinate levitation force and power generation capacity, and improving the slot space utilization and overall operational flexibility of the traditional bearingless electrically excited doubly salient pole motor.

[0058] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A bearingless electrically excited doubly salient pole motor with an improved integrated winding structure, characterized in that, include: Rotor core, stator core, armature winding, and suspension winding; The armature coils wound on the stator poles are connected according to the principle that the change in magnetic flux of the turns is the same, and form the armature winding. ; Armature coils of the same phase are connected in series to form the armature winding of the phase. Each phase armature winding has two terminals and is connected to the external control circuit through these two terminals. A set of radial suspension windings is embedded on every three stator poles. The current of each set of suspension windings is controlled independently. Each set of suspension windings is connected to a separate control circuit. The sets of suspension windings do not interfere with each other. The control circuits connected to the four sets of suspension windings include: The control circuit for the first set of suspended excitation windings includes: a first MOS switch Q1 and a second MOS switch Q2 connected in series; a third MOS switch Q3 and a fourth MOS switch Q4 connected in series; the drains of the first MOS switch Q1 and the third MOS switch Q3 are connected to the positive terminal of the DC voltage source Us; the sources of the second MOS switch Q2 and the fourth MOS switch Q4 are connected to the negative terminal of the DC voltage source Us; and the suspended excitation winding W... sf1 The equivalent Lsf1 and resistor R1 are connected to the source of the first MOS switch Q1 and the source of the third MOS switch Q3, and electrolytic capacitor C1 is connected in parallel across the voltage source Us. The control circuit for the second set of suspended excitation windings includes: a fifth MOSFET Q5 and a sixth MOSFET Q6 connected in series, a seventh MOSFET Q7 and an eighth MOSFET Q8 connected in series, the drains of the fifth MOSFET Q5 and the seventh MOSFET Q7 connected to the positive terminal of the DC voltage source Us, and the sources of the sixth MOSFET Q6 and the eighth MOSFET Q8 connected to the negative terminal of the DC voltage source Us. The suspended excitation winding W... sf2 The equivalent Lsf2 and resistor R2 are connected to the source of the fifth MOS switch Q5 and the source of the seventh MOS switch Q7, and electrolytic capacitor C2 is connected in parallel across the voltage source Us. The control circuit for the third set of suspended excitation windings includes: the ninth MOS switch Q9 and the tenth MOS switch Q10 connected in series, the eleventh MOS switch Q11 and the twelfth MOS switch Q12 connected in series, the drains of the ninth MOS switch Q9 and the eleventh MOS switch Q11 connected to the positive terminal of the DC voltage source Us, and the sources of the tenth MOS switch Q10 and the twelfth MOS switch Q12 connected to the negative terminal of the DC voltage source Us. The suspended excitation winding W... sf3 The equivalent Lsf3 and resistor R3 are connected to the source of the ninth MOS switch Q9 and the source of the eleventh MOS switch Q11, and electrolytic capacitor C3 is connected in parallel across the voltage source Us. The control circuit for the fourth set of suspended excitation windings includes: a thirteenth MOSFET Q13 and a fourteenth MOSFET Q14 connected in series; a fifteenth MOSFET Q15 and a sixteenth MOSFET Q16 connected in series; the drains of the thirteenth MOSFET Q13 and the fifteenth MOSFET Q14 are connected to the positive terminal of the DC voltage source Us; the sources of the fourteenth MOSFET Q14 and the sixteenth MOSFET Q16 are connected to the negative terminal of the DC voltage source Us; and the suspended excitation winding W... sf4 The equivalent Lsf4 and resistor R4 are connected to the source of the thirteenth MOS switch Q13 and the source of the fifteenth MOS switch Q15, respectively. Electrolytic capacitor C4 is connected in parallel across the voltage source Us. The control of the bearingless electrically excited doubly salient pole motor includes: a displacement control module, a suspension current calculation module, and a suspension current control module. The displacement control module acquires reference values ​​of the levitation current in the X and Y directions; In the suspension current calculation module, based on the suspension current reference values ​​in the X and Y directions, the given values ​​of the suspension current in the suspension windings in the X and Y directions are obtained, wherein the two sets of suspension windings correspond to the same direction. In the suspension current control module, the difference between the actual current value of each suspension winding and the given value of the suspension current of each suspension winding obtained by the suspension current calculation step is input into the PI link corresponding to each suspension winding. The four PWM signals output by the suspension current control module are respectively input into the corresponding suspension winding control circuit. The displacement control module includes: The current position of the rotor core is obtained using an eddy current sensor. Then, compared with the rotor position reference value The difference is calculated and input into the X-direction displacement PID control module, which outputs the required suspension force F in the X-axis direction. x * F x * The reference value of the suspension current i is obtained by coordinate transformation of the sampled rotor position angle, armature current, and suspension current. sx * ; The current position y of the rotor core is obtained using an eddy current sensor, and then compared with the rotor position reference value y. * The difference is calculated and input into the Y-direction displacement PID control module, which outputs the required levitation force F in the Y-axis direction. y * , F y * The reference value of the suspension current i is obtained by coordinate transformation of the sampled rotor position angle, armature current, and suspension current. sy * ; Among them, the levitation force vector of the rotor The magnitudes F of the components in the X and Y axes x and F y for: F A1-3 express and The magnitude of the resultant force, F A2-4 express and The magnitude of the resultant force, F B1-3 express and The magnitude of the resultant force, F B2-4 express and The magnitude of the resultant force.

2. The bearingless electrically excited doubly salient pole motor according to claim 1, characterized in that, The bearingless electrically excited doubly salient pole motor adopts a 12 / 8 pole doubly salient pole structure; The rotor core is a salient pole structure, composed of toothed core laminations, and has a total of 8 rotor poles. The stator core is also a salient pole structure with a total of 12 stator poles, and the gaps between adjacent stator poles form stator slots; There are 4 sets of suspended windings.

3. The bearingless electrically excited doubly salient pole motor according to claim 2, characterized in that, An axial armature coil is wound on each stator pole. The armature coils are then grouped together with three adjacent stator poles, resulting in a total of four groups of armature coils. In each group, there are three armature coils. Armature coils belonging to phases A, B, and C respectively, and within each group, those of the same phase. The armature winding that makes up this phase .

4. The bearingless electrically excited doubly salient pole motor according to claim 1, characterized in that, The external rectifier circuit uses a full-bridge uncontrolled rectifier circuit to rectify the alternating current generated on the three-phase armature windings, including: The first rectifier diode D1 and the second rectifier diode D2 are connected in series, the third rectifier diode D3 and the fourth rectifier diode D4 are connected in series, and the fifth rectifier diode D5 and the sixth rectifier diode D6 are connected in series. The cathodes of the first rectifier diode D1, the third rectifier diode D3, and the fifth rectifier diode D5 are connected together, and the anodes of the second rectifier diode D2, the fourth rectifier diode D4, and the sixth rectifier diode D6 are connected together. L mA L mB L mC The input terminals of the three-phase armature windings are interconnected; L mA L mB L mC The output terminals of the three-phase windings are connected to the anodes of the first rectifier diode D1, the second rectifier diode D2, and the third rectifier diode D3, respectively. The capacitor C and the resistor R are connected in parallel, and their two ends are connected to the common cathode and common anode of the diodes, respectively.

5. The bearingless electrically excited doubly salient pole motor according to claim 1, characterized in that, The suspension current calculation section includes: The required reference value of the levitation current in the Y-axis direction Reference value of excitation current required under corresponding operating conditions After performing the addition operation, the suspended excitation winding W is obtained. sf1 The given current in the circuit is used as the given value i for the suspension current of the #1 suspension winding. sf1 * ; The required reference value of the levitation current in the X-axis direction Reference value of excitation current required under corresponding operating conditions After performing the addition operation, the suspension winding W is obtained. sf2 The given current in the circuit is used as the given value i for the suspension current of the #2 suspension winding. sf2 * ; The required reference value of the levitation current in the Y-axis direction Reference value of excitation current required under corresponding operating conditions After subtraction, the suspended excitation winding W is obtained. sf3 The given current in the circuit is used as the given value i for the suspension current of the #3 suspension winding. sf3 * ; The required reference value of the levitation current in the X-axis direction Reference value of excitation current required under corresponding operating conditions After subtraction, the suspended excitation winding W is obtained. sf4 The given current in the circuit is used as the given value i for the #4 suspension winding. sf4 * .

6. The bearingless electrically excited doubly salient pole motor according to claim 1, characterized in that, The suspension current control module includes: W of #1 suspension winding sf1 The actual current i passing through it sf1 The given value i of the corresponding suspension current sf1 * Input the difference value into the PI circuit corresponding to the #1 suspension winding; W of #2 suspension winding sf2 The actual current i passing through it sf2 The given value i of the corresponding suspension current sf2 * Input the difference value into the PI circuit corresponding to the #2 suspension winding; W of the #3 suspension winding sf3 The actual current i passing through it sf3 The given value i of the corresponding suspension current sf3 * Input the difference value into the PI circuit corresponding to the #3 suspension winding; W of the #4 suspension winding sf4 The actual current i passing through it sf4 The given value i of the corresponding suspension current sf4 * Input the difference value into the PI circuit corresponding to the #4 suspension winding.

7. The bearingless electrically excited doubly salient pole motor according to claim 1, characterized in that, The suspension current control module includes: In the displacement control module, four sets of eddy current sensors are used, and the rotor position signal is obtained by measuring the distance between the probe and the reference ring of the rotating shaft. In the suspended excitation current control module, four sets of current Hall sensors are used to measure the current flowing through the four sets of suspended excitation windings.

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