CN115622335B

CN115622335B - Magnetic suspension motor and position detection sensor, detection circuit and bridge circuit thereof

Info

Publication number: CN115622335B
Application number: CN202211638312.6A
Authority: CN
Inventors: 刘德刚; 尹成科
Original assignee: Suzhou Suci Intelligent Technology Co ltd
Current assignee: Suzhou Suci Intelligent Technology Co ltd
Priority date: 2022-12-20
Filing date: 2022-12-20
Publication date: 2023-03-28
Anticipated expiration: 2042-12-20
Also published as: CN115622335A

Abstract

The invention discloses a magnetic suspension motor, a position detection sensor, a detection circuit and a bridge circuit thereof. Sensor bridge circuit of a magnetic levitation motor, comprising: the measuring module comprises at least one inductance detection branch pair; each inductance detection branch pair comprises two inductance detection branches; the inductance detection branch comprises a first inductance detection group and a second inductance detection group; each inductance detection group is composed of at least one inductance; each inductance detection group of the same inductance detection branch is connected in series between the first end and the second end of the excitation source; in the same inductance detection branch circuit, the variation trend of the inductance in the first inductance detection group is opposite to that of the inductance in the second inductance detection group; in the same inductance detection branch circuit pair, the variation trend of the inductance of the first inductance detection group in one inductance detection branch circuit is the same as the variation trend of the inductance of the second inductance detection group in the other inductance detection branch circuit. The technical scheme of the invention can improve the position detection sensitivity and accuracy.

Description

Magnetic suspension motor and position detection sensor, detection circuit and bridge circuit thereof

Technical Field

The invention relates to the technical field of position detection of a magnetic suspension motor, in particular to a magnetic suspension motor and a position detection sensor, a detection circuit and a bridge circuit thereof.

Background

The magnetic suspension motor utilizes the principle that like poles repel and opposite poles attract between the exciting magnetic fields of the stator and the rotor in a bearing system to suspend the rotor, and simultaneously generates a driving force to drive the rotor to move in a suspension state, so that the magnetic suspension motor has the characteristics of small mechanical wear and convenience in maintenance, overhaul and replacement, and is suitable for the fields of severe environments, extremely clean, pollution-free and special needs.

During the operation of the magnetic levitation motor, the position of the rotor thereof needs to be detected. The sensors currently used for position detection are generally inductive, eddy current sensors. In the prior art, the inductive, eddy current sensor detection circuit includes a sensor bridge circuit, as shown in fig. 1, the sensor bridge circuit includes inductances L1 'and L2' having the same impedance variation tendency, which are located on the same side, the inductance L1 'is connected in series with a reference resistance R1 to form a detection branch, the inductance L2' is also connected in series with another reference resistance R2 to form a detection branch, the two detection branches are connected in parallel to both ends of the excitation source, and a potential difference between a connection node N1 'between the inductance L1' and the reference resistance R1 and a connection node N2 'between the inductance L2' and the reference resistance R2 is detected by a signal processing circuit to determine a potential difference between the rotor and the reference direction.

However, in the sensor bridge circuit in the prior art, a reference resistor needs to be used, the sensor bridge circuit needs to have extremely high symmetry, the type selection and matching of the reference resistor are very complicated, the cost is increased, and meanwhile, a sensing system is more redundant, and meanwhile, the sensor bridge circuit is low in detection sensitivity and poor in compatibility, and cannot achieve high-precision measurement.

Disclosure of Invention

The invention provides a magnetic suspension motor, a position detection sensor, a detection circuit and a bridge circuit thereof, which are used for improving the detection sensitivity and accuracy.

According to an aspect of the present invention, there is provided a sensor bridge circuit of a magnetic levitation motor, comprising:

the measuring module comprises at least one inductance detection branch pair; each inductance detection branch pair comprises two inductance detection branches; each inductance detection branch circuit is connected between the first end and the second end of the excitation source in parallel;

the inductance detection branch comprises a first inductance detection group and a second inductance detection group; each inductance detection group is composed of at least one inductance; each inductance detection group of the same inductance detection branch is connected in series between the first end and the second end of the excitation source; the inductors of the first inductance detection group are connected in series between the first end of the excitation source and the output node, and the inductors of the second inductance detection group are connected in series between the second end of the excitation source and the output node; the output nodes electrically connected with the inductance detection groups in different inductance detection branches are different;

in the same inductance detection branch, the variation trend of the inductance in the first inductance detection group is opposite to that of the inductance in the second inductance detection group, and a difference is formed in the same inductance detection branch;

in the same pair of inductance detection branches, the variation trend of the inductance of the first inductance detection group in one inductance detection branch is the same as the variation trend of the inductance of the second inductance detection group in the other inductance detection branch, and a difference is formed between the output nodes of the inductance detection branches.

According to another aspect of the present invention, there is provided a sensor detection circuit of a magnetic levitation motor, including:

a sensor bridge circuit of the magnetic levitation motor;

the signal processing circuit corresponds to at least one inductance detection branch in a sensor bridge circuit of the magnetic suspension motor one to one; each signal processing circuit is used for acquiring the electric potential of the output node of two inductance detection branches in the corresponding inductance detection branch pair and outputting a detection signal.

According to another aspect of the present invention, there is provided a position detection sensor of a magnetic levitation motor, including: the sensor detection circuit of the magnetic suspension motor.

According to another aspect of the present invention, there is provided a magnetic levitation motor incorporating the position detection sensor of the magnetic levitation motor.

According to the technical scheme, at least one inductance detection branch circuit pair is arranged in a sensor bridge circuit, each inductance detection branch circuit pair comprises two inductance detection branch circuits, each inductance detection branch circuit comprises at least two inductance detection groups, each inductance detection group is composed of at least one inductance, in the same inductance detection branch circuit, the variation trend of the inductance in the first inductance detection group is opposite to that of the inductance in the second inductance detection group, a difference is formed in the same inductance detection branch circuit, and in the same inductance detection branch circuit pair, the variation trend of the inductance of the first inductance detection group in one inductance detection branch circuit is the same as that of the inductance of the second inductance detection group in the other inductance detection branch circuit, a difference is formed between output nodes of the inductance detection branch circuits, and position detection is realized by detecting the voltage difference between the output nodes of the two detection branch circuits in the same detection branch circuit pair; meanwhile, the sensor bridge circuit of the invention forms difference between the inductances of different inductance detection groups of the same inductance detection branch circuit and forms difference between the output nodes of different inductance detection branch circuits of the same inductance detection branch circuit pair, thereby having higher sensitivity, being capable of reducing the error of converting the output voltage into the actual displacement in the displacement measurement process, and improving the displacement measurement precision.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present invention, nor do they necessarily limit the scope of the invention. Other features of the present invention will become apparent from the following description.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a sensor detection circuit in the prior art;

FIG. 2 is a schematic diagram of a sensor bridge circuit according to an embodiment of the present invention;

FIG. 3 is a schematic view of a radial working structure of a sensor provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of another sensor bridge circuit according to an embodiment of the present invention;

FIG. 5 is a schematic view of another radial sensor operation provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of a sensor bridge circuit according to yet another embodiment of the present invention;

FIG. 7 is a schematic diagram of yet another sensor bridge circuit according to an embodiment of the present invention;

FIG. 8 is a schematic radial view of another sensor provided in accordance with an embodiment of the present invention;

fig. 9 is a schematic diagram of the structure of an inductor in fig. 3 or fig. 5 or fig. 8;

FIG. 10 is a schematic view of an axial operation of a sensor according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of a sensor bridge circuit corresponding to FIG. 10;

fig. 12 is a schematic perspective view of an inductive sensor according to an embodiment of the present invention;

FIG. 13 is a schematic diagram of a sensor bridge circuit corresponding to FIG. 12;

FIG. 14 is a schematic diagram of yet another sensor bridge circuit according to an embodiment of the present invention;

FIG. 15 is a schematic diagram of a sensor detection circuit according to an embodiment of the present invention;

FIG. 16 is a schematic diagram of another sensor detection circuit according to an embodiment of the present invention;

FIG. 17 is a schematic diagram of a sensor detection circuit according to another embodiment of the present invention;

FIG. 18 is a schematic diagram of a sensor detection circuit according to another embodiment of the present invention;

FIG. 19 is a schematic diagram of a sensor detection circuit according to another embodiment of the present invention;

fig. 20 is a schematic structural diagram of another sensor detection circuit according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The embodiment of the invention provides a sensor bridge circuit of a magnetic suspension motor, which does not need to be provided with reference devices such as resistors and the like, so that extra labor and material cost caused by the matching problem of the reference devices can be avoided, the detection sensitivity is improved, and meanwhile, the error of converting the output voltage into the actual displacement in the displacement measurement process can be reduced, so that the displacement measurement precision is improved.

Fig. 2 is a schematic structural diagram of a sensor bridge circuit provided in an embodiment of the present invention, and as shown in fig. 2, the sensor bridge circuit includes a measurement module 100; the measurement module 100 comprises at least one pair of inductance detection branches 10; each inductance detection branch pair 10 comprises two inductance detection branches 11, and each inductance detection branch 11 is connected in parallel between a first end and a second end of an excitation source AC; the inductance detection branch 11 includes two inductance detection sets 111, namely a first inductance detection set 101 and a second inductance detection set 102, each inductance detection set 111 is composed of at least one inductance, and each inductance detection set 111 of the same inductance detection branch 11 is connected in series between a first end and a second end of the excitation source AC; the inductance of the first inductance detection group 101 is connected in series between the first end of the excitation source AC and the output node (N1/N2), and the inductance of the second inductance detection group 102 is connected in series between the second end of the excitation source AC and the output node (N1/N2); wherein, the output nodes electrically connected to the inductance detection sets 111 in different inductance detection branches 11 are different; in the same inductance detection branch 11, the variation trend of the inductance in the first inductance detection group 101 is opposite to that of the inductance in the second inductance detection group 102, and a difference is formed in the same inductance detection branch; in the same inductance detecting branch pair 10, the trend of the inductance of the first inductance detecting group 101 in one inductance detecting branch 1101 (1102) is the same as the trend of the inductance of the second inductance detecting group 102 in the other inductance detecting branch 1102 (1101), and a difference is formed between the output nodes of the inductance detecting branches. Therefore, position detection can be realized by detecting the voltage difference between the output nodes of two detection branches in the same detection branch pair, and compared with the prior art, the four inductance detection groups of the two inductance detection branches independently form a bridge without arranging other devices except for the inductance in a sensor bridge circuit, so that the problem caused by the additional cost of manpower and material resources due to the matching of other devices can be prevented; meanwhile, the sensor bridge circuit of the invention forms difference on the same detection branch circuit and forms difference between the output nodes of different inductance detection branch circuits of the same inductance detection branch circuit pair, thus having higher sensitivity, being capable of reducing the error of converting the output voltage into actual displacement in the displacement measurement process, and further improving the displacement measurement precision.

Illustratively, the measurement module 100 includes an inductance detection branch pair 10, the inductance detection branch pair 10 includes two

inductance detection branches

1101 and 1102, each inductance detection branch 11 includes two inductance detection groups 111, that is, a first inductance detection group 101 and a second inductance detection group 102, each inductance detection group 111 includes one inductance as an example, in this case, the inductance detection branch pair 10 includes four inductances L1, L2, L3 and L4, that is, the inductance detection branch 1101 includes an inductance L1 and an inductance L2, a first end of the inductance L1 is electrically connected to a first end of the excitation source AC, a second end of the inductance L1 is electrically connected to a first end of the inductance L2 at a first output node N1, and a second end of the inductance L2 is electrically connected to a second end of the excitation source AC; the inductance detection branch 1102 includes an inductance L3 and an inductance L4, a first end of the inductance L4 is electrically connected to a first end of the excitation source AC, a second end of the inductance L4 and a first end of the inductance L3 are electrically connected to the second output node N2, and a second end of the inductance L3 is electrically connected to a second end of the excitation source AC. The inductance L1 and the inductance L2 have opposite changing trends, and the inductance L3 and the inductance L4 have opposite changing trends, while the inductance L1 and the inductance L3 have the same changing trend, and the inductance L2 and the inductance L4 have the same changing trend.

It can be understood that the trend of the change is opposite to the trend that the impedance of one of the inductors is increased and the impedance of the other inductor is decreased; the same trend of change is specifically that the impedances of the two inductors are simultaneously increased or decreased, that is, when the impedances of the inductor L1 and the inductor L3 are simultaneously increased, the impedances of the inductor L2 and the inductor L4 are simultaneously decreased.

For example, fig. 3 is a schematic radial working diagram of a sensor provided in an embodiment of the present invention, and referring to fig. 2 and fig. 3 in combination, when a rotor H in a bearing system in a magnetic levitation motor is used as a conductor to be measured, an inductor L1 and an inductor L2 may be symmetrically disposed in the bearing system (e.g., a stator T) of the magnetic levitation motor, and an inductor L3 and an inductor L4 may also be symmetrically disposed in the stator T of the magnetic levitation motor, so that when the rotor H moves in a direction close to the inductor L1 and the inductor L3, the rotor H moves in a direction away from the inductor L2 and the inductor L4, the magnetic field coupling strength between the inductor L1 and the inductor L3 and the rotor H increases, the impedance of the inductor L1 and the inductor L3 increases, and the magnetic field coupling strength between the inductor L2 and the inductor L4 and the rotor decreases, and the impedance of the inductor L2 and the inductor L4 decreases; similarly, when the rotor H moves toward the direction close to the inductance L2 and the inductance L4, it also moves away from the inductance L1 and the inductance L3, so that the inductance L1 and the inductance L3 have the same impedance variation trend, the inductance L2 and the inductance L4 have the same variation trend, the inductance L1 and the inductance L2 have the opposite variation trend, and the inductance L3 and the inductance L4 also have the opposite variation trend. Therefore, two inductors with opposite impedance variation trends are arranged on the same inductor detection branch, and the two inductors with the same inductance variation trend are respectively arranged on the two inductor detection branches and are electrically connected to different output nodes and excitation sources in a diagonal manner, so that when the rotor is displaced, the voltage variation trends at the output nodes on the two inductor detection branches are opposite, and a certain voltage difference exists. For example, when the impedances corresponding to the inductances L1, L2, L3, and L4 are Z1, Z2, Z3, and Z4, respectively, if the rotor H is not moving, Z1 = Z2 = Z3 = Z4 = Z, and at this time, the voltage difference V0= V1-V2=0 between the voltage V1 of the first output node N1 and the voltage V2 of the second output node N2; when the rotor H moves, for example, when the rotor H approaches to the inductance L1 and the inductance L3, Z1 = Z3 = Z + M × Z, and Z2 = Z4 = Z-M × Z, where M is a coefficient related to a distance of the rotor H moving, and at this time, a voltage difference V0 between the voltage V1 of the first output node N1 and the voltage of the second output node N2 is:

in this way, the displacement condition of the rotor H can be determined by the voltage difference between the first output node N1 and the second output node N2, so that the position detection of the rotor H is realized.

Likewise, taking the prior art shown in fig. 1 as an example, if R =2Z, and the impedance Z1 ″ = Z2 ″ -of the inductances L1 'and L2' when the rotor is not displaced; when there is a displacement, for example when approaching the inductance L1 ″, the impedance Z1 ″ = Z + M ″, of the inductance L1 ″, and the impedance Z2 ″ = Z-M ″, of the inductance L2 ″, at which time the difference V0 ' between the voltage V1 ' of the first output node N1 ' and the voltage V2 ' of the second output node N2 ' is:

taking M =0.1 as an example, V0= 0.1v, v0= -0.05V can be known. Therefore, compared with the differential sensor bridge circuit in the prior art shown in fig. 1, the sensitivity of the sensor bridge circuit provided by the embodiment of the invention is improved by two times, which reduces the error of converting the output voltage into the actual displacement in the displacement measurement process, thereby improving the displacement measurement precision; compared with the non-differential sensor bridge circuit in the prior art, the sensitivity of the sensor bridge circuit provided by the embodiment of the invention is improved by four times.

In addition, the sensor bridge circuit provided by the embodiment of the invention only needs to use the inductor to form the bridge circuit, so that the use of a reference resistor is omitted, the matching property of the resistor does not need to be considered due to the symmetry of the sensor bridge circuit, the labor and material cost is saved, the redundancy of the sensor bridge circuit is reduced, and the stability of the system is improved.

It is understood that the above is only exemplary, so that when the rotor is not displaced, the impedance of each inductor is the same, so that the voltage difference between the first output node and the second output node is 0, and in the embodiment of the present invention, when the rotor is not displaced, the impedance of each inductor may also have a fixed difference, at this time, the voltage difference between the first output node and the second output node may be a fixed value not equal to 0, at this time, when the rotor is moved, the position of the rotor may also be determined according to the voltage difference between the first output node and the second output node.

It should be noted that fig. 2 and fig. 3 are only exemplary diagrams of the embodiment of the present invention, and fig. 2 and fig. 3 only exemplarily show that the measurement module 100 includes one inductance detection branch pair 10, and the inductance detection branch pair 10 includes two inductance detection branches 11, and by a voltage difference between two output nodes N1 and N2 of the two inductance detection branches 11, a displacement amount of the rotor H in the Y direction can be detected, so as to determine a position of the rotor H in the Y direction. In the embodiment of the present invention, the number of the inductance detection branch pairs in the measurement module may also be an integer greater than or equal to 2, and displacement amounts of the rotor in a plurality of different directions may be detected, so as to determine a position of the rotor H on a plane or a space.

In an alternative embodiment, fig. 4 is a schematic structural diagram of another sensor bridge circuit provided in an embodiment of the present invention, and as shown in fig. 4, at least one inductance detecting branch pair 10 of the measuring module 100 includes two inductance detecting branch pairs 1001 and 1002, and each inductance detecting branch pair 10 includes two inductance detecting branches 11, and each inductance detecting branch 11 includes two inductance detecting groups, that is, a first inductance detecting group 101 and a second inductance detecting group 102. At this time, the position of the rotor H on a certain plane is determined by the voltage difference between the output nodes N11 and N21 of the two inductance detecting branches 11 in the pair of inductance detecting branches 1001 and the voltage difference between the output nodes N12 and N22 of the two inductance detecting branches 11 in the pair of inductance detecting branches 1002.

Exemplarily, fig. 5 is a radial operation schematic diagram of another sensor provided by the embodiment of the present invention, and referring to fig. 4 and fig. 5 in combination, taking an example that an inductance detection set in each inductance detection branch 11 includes an inductance, in this case, one inductance detection branch 11 of the inductance detection branch pair 1001 includes inductances L1 and L2, and the other inductance detection branch 11 includes inductances L3 and L4, where the inductance L1 and the inductance L2 are connected in series and the inductance L1 and the inductance L2 are electrically connected to the output node N11, the inductance L3 and the inductance L4 are connected in series and the inductance L3 and the inductance L4 are electrically connected to the output node N21; the inductor L1 and the inductor L2 may be arranged and symmetrically arranged along a radial direction, the inductor L3 and the inductor L4 may also be arranged and symmetrically arranged along a radial direction, the inductor L1 and the inductor L3 are arranged on the same side, and the inductor L3 and the inductor L4 are arranged on the same side. One inductance detection branch 11 of the inductance detection branch pair 1002 comprises inductances L5 and L6, the other inductance detection branch 11 comprises inductances L7 and L8, the inductance L5 and the inductance L6 are connected in series, the inductance L5 and the inductance L6 are electrically connected to the output node N12, the inductance L7 and the inductance L8 are connected in series, and the inductance L7 and the inductance L8 are electrically connected to the output node N22; the inductor L5 and the inductor L6 may be arranged along the radial direction and symmetrically disposed, the inductor L7 and the inductor L8 may also be arranged along the radial direction and symmetrically disposed, the inductor L5 and the inductor L7 may be disposed on the same side, and the inductor L6 and the inductor L8 may be disposed on the same side. Wherein, the symmetry axis A1 of the inductor L5 and the inductor L6 may be perpendicular to the symmetry axis B1 of the inductor L1 and the inductor L2, and the symmetry axis A2 of the inductor L7 and the inductor L8 may be perpendicular to the symmetry axis B1 of the inductor L3 and the inductor L4.

In this way, the position of the rotor H in the Y direction can be determined by obtaining the voltage difference between the output nodes N11 and N21 in the inductance detection branch pair 1001, and the position of the rotor H in the X direction can be determined by obtaining the voltage difference between the output nodes N12 and N22 in the inductance detection branch pair 1002, so that the position coordinates of the rotor H on the plane formed by the X direction and the Y direction can be determined by combining the voltage difference between the output nodes N11 and N21 in the inductance detection branch pair 1001 and the voltage difference between the output nodes N12 and N22 in the inductance detection branch pair 1002, and the specific position of the rotor H can be determined.

It can be understood that fig. 2 and fig. 4 both exemplarily show a case that each inductance detection branch includes two inductance detection groups, and each inductance detection group includes one inductance, but each inductance detection branch may also include more than two inductance detection groups in the embodiment of the present invention, and each inductance detection group may also include two or more than two inductances, which may be designed according to actual needs, and this is not specifically limited in the embodiment of the present invention.

For example, fig. 6 is a schematic structural diagram of another sensor bridge circuit provided by an embodiment of the present invention, and referring to fig. 5 and 6 in combination, a measurement module 100 includes an inductance detection branch pair 10, where the inductance detection branch pair 10 includes two detection branches 11, each detection branch 11 includes two inductance detection sets 111, each inductance detection set 111 includes two inductors, that is, a first inductance detection set 101 of inductance detection branch 1101 includes inductors S11 and S12, a second inductance detection set 102 of inductance detection branch 1101 includes inductors S21 and S22, the first inductance detection set 101 of inductance detection branch 1102 includes inductors S41 and S42, and the second inductance detection set 102 of inductance detection branch 1102 includes inductors S31 and S32, where when rotor H moves in the Y direction, the trend of the total impedance change of inductors S31 and S32 is opposite to the trend of the total impedance change of inductors S41 and S42, and the trend of the total impedance change of inductors S11 and S12 is the same as the trend of the total impedance change of inductors S21 and S22; likewise, when the rotor H moves in the Y direction, the tendency of the total impedance of the inductors S11 and S12 to change is the same as that of the inductors S31 and S32, and the tendency of the total impedance of the inductors S21 and S22 to change is the same as that of the inductors S41 and S42. In this manner, the position of the rotor H in a certain direction can be detected as well.

In another exemplary embodiment, as shown in fig. 7, each inductance detection group 111 may further include three inductances, for example, the first inductance detection group 101 of the inductance detection branch 1101 includes inductances L1, L2 and L3, the second inductance detection group 102 of the inductance detection branch 1101 includes inductances L10, L11 and L12, the first inductance detection group 101 of the inductance detection branch 1102 includes inductances L7, L8 and L9, the second inductance detection group 102 of the inductance detection branch 1101 includes inductances L4, L5 and L6, when the trend of the total impedance of the inductances L1, L2 and L3 is opposite to the trend of the total impedance of the inductances L10, L11 and L12, the trend of the total impedance of the inductances L1, L2 and L3 is the same as the trend of the total impedance of the inductances L4, L5 and L6, and the trend of the total impedance of the inductances L7, L8 and L9 is the same as the trend of the total impedance of the inductances L4, L5 and L6, and the trend of the inductance L7, L8 and L9 is the same as the trend of the change of the total impedance of the inductances L10, L11 and L12, so that the trend of the total impedance of the trend of the inductance detection branch 1101 and the total impedance of the rotor can be implemented to detect the total impedance of the rotor.

For convenience of description, in the embodiments of the present invention, without special description, each inductance detection branch includes two inductance detection groups, and each inductance detection group includes one inductance.

It should be understood that the above description only exemplarily shows that the inductors in each inductance detecting branch 11 are fixed on the stator T and sequentially arranged along the circumferential direction of the stator, but in the embodiment of the present invention, the inductors in each inductance detecting branch 11 may be separately arranged and sequentially arranged along the circumferential direction with the ideal working position of the rotor H as the center of a circle, and the same points may refer to the above description and are not repeated herein. For convenience of description, the embodiments of the present invention are all schematically illustrated in terms of examples in which the inductances in the inductance detection branches 11 can be sequentially arranged along the circumferential direction of the stator T.

It should be noted that, as shown in fig. 3 and 5, when the magnetic levitation electric machine includes a rotor H and a stator T, the above only exemplarily shows that the rotor H of the magnetic levitation electric machine is displaced along the radial direction of the stator T, that is, the inductances in the inductance detection branches 11 may be sequentially arranged along the circumferential direction of the stator T, and in this case, at least one inductance detection branch pair 10 includes at least one first inductance detection branch pair 1010; in the first inductance detecting branch pair 1010, the inductance of the first inductance detecting group 101 and the inductance of the second inductance detecting group 102 of the same inductance detecting branch 11 are arranged in the radial direction and are symmetrically arranged.

Illustratively, with continuing reference to fig. 4 and 5, when the rotor H moves toward the direction approaching the inductors L1 and L3 and toward the inductors L6 and L8, the rotor H moves toward the direction away from the inductors L4 and L2 and toward the inductors L7 and L5, at which time the impedances of the inductors L1 and L3 increase and the inductors L6 and L8 increase, while the impedances of the inductors L2 and L4 decrease and the inductors L5 and L7 decrease, so that the voltage difference between the output node N11 and the output node N21 is positive and the voltage difference between the output node N12 and the output node N22 is negative, and the specific movement orientation of the rotor H can be determined based on the positive and negative voltage differences of the output nodes (N11 and N21, N12 and N22) of the detection branches 11 in the same inductance detection branch pair 10, while the specific movement orientation of the rotor H can be determined based on the difference of the output nodes (N11 and N21, N12 and N22) of the detection branches 11 in the same inductance detection branch pair 10, and the position of the rotor H and the movement of the rotor H can be determined in real time.

Optionally, with continuing to refer to fig. 4 and fig. 5, when the inductance L1 (L4, L5, or L8) of the first inductance detection group 101 and the inductance L2 (L3, L6, or L7) of the second inductance detection group 102 of the same inductance detection branch 11 are arranged and symmetrically arranged in the radial direction, in the same inductance detection branch 11, the center line of the inductance L1 (L4, L5, or L8) of the first inductance detection group 101 and the center line of the inductance L2 (L3, L6, or L7) of the second inductance detection group 102 are the same first straight line A1 (A2, B1, or B2) extending in the radial direction, and the symmetry axis of the inductance L1 (L4, L5, or L8) of the first inductance detection group 101 and the symmetry axis of the inductance L2 (L3, L6, or L7) of the second inductance detection group 102 are the first symmetry axis B1 (B2, A1, or A2) extending in the radial direction; the first straight line A1 (A2, B1, or B2) is perpendicular to the first axis of symmetry B1 (B2, A1, or A2) and passes through a center O of the stator T.

Exemplarily, the center lines of the inductance L1 and the inductance L2 of the same inductance detection branch 11 are the same first straight line A1, the symmetry axes of the inductance L1 and the inductance L2 are the first symmetry axis B1, at this time, the first straight line A1 and the first symmetry axis B1 are mutually perpendicular and pass through the circle center O of the stator T, so that the inductance L1 and the inductance L2 can be symmetrical structures arranged on the circumference of the stator T, thereby being convenient for confirming the impedance change conditions of the inductance L1 and the inductance L2, and further being capable of accurately determining the relative positions of the rotor H and the inductance L1 and the inductance L2.

Correspondingly, the center lines of the inductor L3 and the inductor L4 of the same inductor detection branch 11 are the same first straight line A2, the symmetry axis of the inductor L3 and the symmetry axis of the inductor L4 is the first symmetry axis B2, and at this time, the first straight line A2 and the first symmetry axis B2 are perpendicular to each other and pass through the circle center O of the inductor sensor T; the center lines of the inductor L5 and the inductor L6 of the same inductor detection branch 11 are the same first straight line B1, the symmetry axis of the inductor L5 and the symmetry axis of the inductor L6 is the first symmetry axis A1, and at the moment, the first straight line B1 and the first symmetry axis A1 are perpendicular to each other and pass through the circle center O of the stator T; and the center lines of the inductor L7 and the inductor L8 of the same inductor detection branch 11 are the same first straight line B2, the symmetry axes of the inductor L7 and the inductor L8 are the first symmetry axis A2, and at this time, the first straight line B2 and the first symmetry axis A2 are perpendicular to each other and pass through the circle center O of the stator T.

Alternatively, with continuing reference to fig. 4 and 5, if at least one inductance detecting branch pair 10 includes a first inductance detecting branch pair 1010, when the distance from the ideal working position in the radial direction of the rotor H is 0, the potential difference between the output nodes (N11 and N21, or N12 and N22) of the two inductance detecting branches 11 of the same first inductance detecting branch pair 1010 is 0V.

Specifically, taking the first inductance detecting branch pair 1001 as an example, when the rotor H is at the radial ideal working position, the impedance values of the inductances L1, L2, L3, and L4 in the first inductance detecting branch pair 1001 may be the same; when the rotor H is displaced relative to the ideal radial working position, the impedance values of the inductors L1, L2, L3, and L4 change relatively, and the absolute values of the impedance value variations of the inductors L1, L2, L3, and L4 can be kept consistent, so that when the position of the rotor H is determined according to the voltage difference between the output nodes N11 and N21, the signal processing amount can be simplified, the signal processing efficiency can be improved, the structure of a signal processing circuit for acquiring and processing the voltage difference between the output nodes N11 and N21 can be simplified, and the cost of the signal processing circuit can be reduced.

Optionally, fig. 8 is a schematic radial working diagram of another sensor provided in an embodiment of the present invention, and referring to fig. 8, when at least one inductance detecting branch pair includes a first inductance detecting branch pair, inductors in the first inductance detecting branch pair are sequentially arranged along a circumferential direction of the stator T, and a distance between any two adjacent inductors is a fixed value.

Illustratively, taking two first inductance detecting branch pairs as an example, one inductance detecting branch of one first inductance detecting branch pair may include inductances L1, L2, L9 and L10, the inductances L1 and L2 are connected in series between the first end of the excitation source and the output node, the inductances L9 and L10 are connected in series between the output node and the second end of the excitation source, the other inductance detecting branch may include inductances L11, L12, L3 and L4, the inductances L11 and L12 are connected in series between the first end of the excitation source and the output node, and the inductances L3 and L4 are connected in series between the output node and the second end of the excitation source; one of the inductance detection branches of the other first inductance detection branch pair may include inductances L5, L6, L13 and L14, the inductances L5 and L6 are connected in series between the first end of the excitation source and the output node, the inductances L13 and L14 are connected in series between the output node and the second end of the excitation source, the other inductance detection branch may include inductances L15, L16, L7 and L8, the inductances L15 and L16 are connected in series between the first end of the excitation source and the output node, and the inductances L7 and L8 are connected in series between the output node and the second end of the excitation source; at this time, 16 inductors are arranged in the sensor bridge circuit, and the 16 inductors may be sequentially arranged along the circumferential direction of the stator T, for example, the inductors L1 to L16 are sequentially arranged along the circumferential direction of the stator T, and the distance between the inductor L1 and the inductor L2 in the circumferential direction is equal to the distance between the inductor L1 and the inductor L16 in the circumferential direction, and meanwhile, the distance between the inductor L1 and the inductor L2 in the circumferential direction is also equal to the distance between the inductor L3 and the inductor L4 in the circumferential direction, that is, the distance between any two adjacent inductors in the circumferential direction is the same, so that the inductors may be uniformly distributed in the circumferential direction of the stator T, and thus, when the rotor H moves, the variation of each inductor is equivalent, so that when the position of the rotor H is determined according to the difference between two output nodes in the same first inductance detection branch pair, the logical operation process may be simplified.

In an alternative embodiment, the first inductance detecting branch pair is arranged along the circumferential direction of the stator T, and the included angle β between the center lines of any two adjacent inductors is 20 ° to 30 °, for example, the center lines of the inductor L1 and the inductor L2 both pass through the center of the circumference of the stator T, and at this time, the included angle between the center lines of the inductor L1 and the inductor L2 is 30 °. In this way, the included angle β between the center lines of two adjacent inductors is 30 °, that is, the circumferential angle is an integral multiple of the included angle β between the center lines of two adjacent inductors, so as to ensure that the inductors in the first inductor detecting branch pair can be uniformly distributed in the circumferential direction of the stator T.

In each of the above or below embodiments of the present patent, the inductor is not limited to the implementation of a single inductor, for example, the inductor may include the implementation of a single inductor, and may also include the implementation of a nonzero even number of inductors. With a single inductor, the inductor may include an inductor coil and a magnetic pot for forming a magnetic field loop of the inductor coil. When the number of the inductance coils is non-zero and even, the inductance can comprise non-zero and even adjacent magnetic poles and inductance coils wound on each magnetic pole, and the non-zero and even adjacent inductance coils are pairwise paired to form inductance coil pairs; the two inductance coils of each inductance coil pair are connected in series; the two magnetic poles of each inductance coil pair have opposite polarities and are used for forming a magnetic field loop of the inductance coil pair. As an embodiment, taking a case that a nonzero and even number of adjacent magnetic poles are two magnetic poles as an example, the inductor may further include a magnetic conductive material (such as a ring-shaped silicon steel sheet, but not limited thereto) connecting the two magnetic poles, referring to fig. 9, fig. 9 is a structural schematic diagram of an inductor in fig. 3 or fig. 5 or fig. 8, the inductor L1 includes two magnetic poles, a magnetic conductive material connecting the two magnetic poles, and two inductor coils S11, S12, one end of the two inductor coils is connected in series to form an inductor coil pair, the two magnetic poles have opposite polarities, such as one magnetic pole is an N pole, the other magnetic pole is an S pole, and the two magnetic poles and the magnetic conductive material are used to form a magnetic field loop of the inductor coil pair. In other embodiments, the inductor may further include four magnetic poles, a magnetic conductive material connecting the four magnetic poles, and four inductor coils, where the four inductor coils form two inductor coil pairs, the two inductor coils of each inductor coil pair are connected in series, the two magnetic poles of each inductor coil pair have opposite polarities, one magnetic pole is an N pole, the other magnetic pole is an S pole, and the two magnetic poles and the magnetic conductive material are used to form a magnetic field loop of the inductor coil pair. Preferably, when one magnetic pole of one inductor pair is adjacent to one magnetic pole of another inductor pair, the two magnetic poles have the same polarity, for example, when one magnetic pole is N-pole, the other magnetic pole is also N-pole. For example, if a magnetic pole of one inductor pair is adjacent to a magnetic pole of another inductor pair but the distance between the two magnetic poles allows, the polarities of the two magnetic poles may be opposite. In the same principle, referring to fig. 8, when a magnetic pole of one inductor is adjacent to a magnetic pole of another inductor between two adjacent inductors, the two magnetic poles have the same polarity, for example, when one magnetic pole is N-pole, the other magnetic pole is also N-pole. But not limited thereto, for example, in the case that one magnetic pole of one inductor is adjacent to one magnetic pole of the other inductor but the distance allows, the polarities of the two magnetic poles may be opposite. In the above or following embodiments of the present invention, the concept of the magnetic pole may be an independent component of the magnetic core serving as the coil, or may be a tooth integrally formed with an annular silicon steel sheet, which is not specifically limited in the embodiments of the present invention; the concept of the coil may be a pure coil or an assembly including a bobbin, and the embodiment of the present invention is not particularly limited thereto. In the above or below embodiments of the present patent, the practical application scenario of the inductors is not defined, as a preferred embodiment, each inductor may be defined as one sensor, but is not limited thereto, and in other embodiments, each inductor may also be defined as a series connection or a parallel connection of a plurality of sensors.

In an alternative embodiment, fig. 10 is a schematic diagram of an axial operation of a sensor provided in an embodiment of the present invention, fig. 11 is a schematic diagram of a structure of a sensor bridge circuit corresponding to fig. 10, and referring to fig. 10 and fig. 11 in combination, when the magnetic levitation motor includes a rotor T and a stator T, the rotor H can also be displaced along an axial direction Z of the inductance sensor T, in this case, at least one inductance detecting branch pair 10 includes at least one second inductance detecting branch pair 1020; in the second inductance detecting branch pair 1020, the inductances of the first inductance detecting group 101 and the second inductance detecting group 102 of the same inductance detecting branch 11 are arranged along the axial direction Z and are symmetrically arranged.

Exemplarily, one of the inductive detection branches 1103 of this second inductive detection branch pair 1020 includes an inductance L1 ' and L2 ', and the other inductive detection branch 1104 includes an inductance L3 ' and L4 ', wherein the inductances L1 ' and L2 ' are connected in series to the first and second ends of the excitation source, and the inductances L1 ' and L2 ' are electrically connected to the output node N1 ', and the inductances L3 ' and L4 ' are connected in series to the first and second ends of the excitation source, and the inductances L3 ' and L4 ' are electrically connected to the output node N2 ', when the rotor moves in the axial direction Z of the stator T, the inductances L1 ' and L4 ' are arranged in series and the inductances L3 ' and L4 ' are oppositely shifted, and the inductances L3 ' and L4 ' are arranged in the axial direction and the inductances L3 ' are shifted; when the rotor moves in the axial direction Z of the stator T, the inductance L1 'is identical to the impedance variation tendency of the inductance L3', and the inductance L2 'is identical to the variation tendency of the inductance L4', i.e., the inductance L1 'and the inductance L3' are arranged on the same side of the stator T in the axial direction, and the inductance L2 'and the inductance L4' are arranged on the same side of the stator T in the axial direction. In this way, by obtaining an inductance difference between the output node N1 'and the output node N2', a variation of the inductances L1 ', L2', L3 'and L4' can be determined, so as to determine a displacement amount of the rotor in the axial direction Z of the stator T, and then determine a specific position of the rotor in the axial direction Z of the stator T, thereby implementing position detection of the rotor.

Optionally, if at least one inductance detection branch pair includes a second inductance detection branch pair, when the distance from the ideal axial working position of the rotor in the axial direction Z is 0, the potential difference between the output nodes of the two inductance detection branches of the same second inductance detection branch pair is 0V.

Illustratively, when the rotor is at a distance of 0 from the axial ideal working position in the axial direction Z, the inductance L1 ″, L2 ″, L3 ″, and L4 ″, the impedance Z1 ″' -is = Z2 ″ -Z4 ″, such that the potential difference between the output node N1 ″, of the inductance detection branch 1103 and the output node N2 ″, of the inductance detection branch 1104 in the second pair of inductance detection branches is 0V, and when the rotor moves in the axial direction Z, the impedance Z1 ″, L3 ″, and L4 ″, respectively, is altered such that the output potential difference of the inductance L1 ″, L2 ″, L3 ″, and L4 ″, respectively, is determined such that the impedance of the pair of the inductance detection branches is equal to the impedance of the corresponding pair of the inductance detection branches, and the impedance of the pair of inductance detection branches is then changed.

In an optional embodiment, when the first inductance detection group and the second inductance detection group of the same inductance detection branch of the second inductance detection branch pair are arranged and symmetrical in the axial direction, the center line of the inductance in the first inductance detection group and the center line of the inductance in the second inductance detection group are symmetrical along the axial center line.

Exemplarily, as shown in fig. 10, the inductance L1 'and the inductance L2' of the same inductive detection branch are symmetric, when the center line a of the inductance L1 'and the center line B of the inductance L2' are symmetric along the axial center line C; and, the inductance L3 'and the inductance L4' of the same inductance detection branch are symmetric, at this time, the center line a of the inductance L3 'and the center line B of the inductance L4' are symmetric along the axial center line C; meanwhile, the center line a of the inductor L1 'and the center line a of the inductor L3' are the same straight line, and the center line B of the inductor L3 'and the center line B of the inductor L4' are the same straight line and the same center line, that is, the center lines of the inductors having the same variation tendency are the same center line in the same second inductance detection branch.

It is understood that the above description is only exemplary in the case that one pair of second inductance detecting branches is included in the sensor bridge circuit, and the number of the pair of second inductance detecting branches may also include a plurality in the embodiment of the present invention. As shown in fig. 12 and 13, the sensor bridge circuit comprises two pairs of second inductive detection branches 1020 (1003 and 1004), one pair of which includes an inductance L1 ', an L3 ', an L4 ', each of which includes two inductive coils and corresponding two magnetic poles, i.e. an inductance L1 ' comprising an inductive coil S11 ' and an S12 ' and two magnetic poles corresponding to the inductive coils S11 ' and S22 ', and an inductance L3 ' comprising an inductive coil S31 and an inductive coil S42 ' corresponding to the inductive coil S31 ', and an inductive coil S42; likewise, the other second pair of inductance detection branches 1004 comprises an inductance L5 ', L6', L7 ', L8', each of which comprises two inductance coils and two corresponding magnetic poles, i.e. an inductance L5 'comprising the inductance coils S51' and S52 ', and two magnetic poles corresponding to the inductance coils S51' and S52 ', the inductance L6' comprising the inductance coils S61 'and S62', and two magnetic poles corresponding to the inductance coils S61 'and S62', and the inductance L7 'comprising the inductance coils S71' and S72 ', and the two magnetic poles corresponding to the inductance coils S81' and S82 '″, and the inductance L8' comprising the inductance coils S81 'and S81', and the two magnetic poles corresponding to the inductance coils S81 'and S82'; two inductance coils of the same inductance are connected in series, and the two magnetic poles of the same inductance are opposite in polarity, for example, one magnetic pole is an N pole, the other magnetic pole is an S pole, and the two magnetic poles and the magnetic conduction material are used for forming a magnetic field loop of the inductance coils. On the premise of realizing the core invention point of the embodiment of the present invention, the embodiment of the present invention does not specifically limit the number of the second inductance detection branch pairs in the sensor bridge circuit.

In yet another alternative embodiment, fig. 14 is a schematic structural diagram of another sensor bridge circuit provided in the embodiment of the present invention, and as shown in fig. 14, the sensor bridge circuit includes two first inductance detecting branch pairs 1010 and one second inductance detecting branch pair 1020, where one first inductance detecting branch pair 1001 of the two first inductance detecting branch pairs 1010 includes inductances L1, L2, L3, and L4, and inductances L1 and L2 belong to one inductance detecting branch 1101, that is, inductance L1 and inductance L2 are connected in series to a first end and a second end of an excitation source AC, and inductance L1 and inductance L2 are electrically connected to an output node N11, inductances L3 and L4 belong to one inductance detecting branch 1102, that is, inductance L3 and inductance L4 are connected in series to a first end and a second end of the excitation source AC, and inductance L3 and inductance L4 are electrically connected to an output node N21; the other first inductance detecting branch pair 1002 includes inductances L5, L6, L7 and L8, the inductances L5 and L6 belong to the same inductance detecting branch 1101, that is, the inductance L5 and the inductance L6 are connected in series to the first end and the second end of the excitation source AC, the inductance L5 and the inductance L6 are electrically connected to the output node N12, the inductance L7 and the inductance L8 belong to the same inductance detecting branch 1102, that is, the inductance L7 and the inductance L8 are connected in series to the first end and the second end of the excitation source AC, and the inductance L7 and the inductance L8 are electrically connected to the output node N22; the second inductance detection branch pair 1020 includes an inductance L1 ', L2', L3 ', and L4', and the inductance L1 'and L2' are identically one inductance detection branch 1103, i.e., the inductance L1 'and the inductance L2' are connected in series to the first end and the second end of the excitation source AC, and the inductance L1 'and the inductance L2' are electrically connected to the output node N1 ', the inductance L3' and the inductance L4 'are electrically connected to the first end and the second end of the excitation source AC, and the inductance L3' and the inductance L4 'are identically one inductance detection branch 1104, i.e., the inductance L3' and the inductance L4 'are connected in series to the first end and the second end of the excitation source AC, and the inductance L3' and the inductance L4 'are electrically connected to the output node N2'. In this way, the relative position of the rotor in one of the radial directions can be determined by the voltage difference between output nodes N11 and N21 in first pair of inductance detection branches 1001, the relative position of the rotor in the other radial direction can be determined by the voltage difference between output nodes N12 and N22 in first pair of inductance detection branches 1002, and the relative position of the rotor in the axial direction can be determined by the voltage difference between output nodes N1 'and N2' in second pair of inductance detection branches 1020, so as to implement detection of the relative position of the rotor in space.

Optionally, with continued reference to fig. 12, the stator may include a first substrate T1, a second substrate T2, and a third substrate T3 sequentially arranged along the axial direction, at this time, if at least one inductance detection branch pair includes a first inductance detection branch pair and a second inductance detection branch pair, each inductance of the first inductance detection branch pair is arranged along the circumferential direction of the second substrate T2, and each inductance of one inductance detection group in the inductance detection branches of the second inductance detection branch pair is arranged along the circumferential direction of the first substrate T1, and each inductance of the other inductance detection group is arranged along the circumferential direction of the third substrate T3. So, each inductance of second inductance detection branch road centering distributes in the relative both sides of each inductance of first inductance detection branch road centering to under the prerequisite that each inductance of first inductance detection branch road centering and each inductance of second inductance detection branch road centering do not influence each other, can realize simultaneously detecting the position of rotor at axial direction and radial direction.

Specifically, the magnetic poles of the inductors with the same change trend in the same inductance detection branch pair can form a dipole, when the rotor moves, the size or the direction of the magnetic field of the magnetic poles of the dipole changes, so that the self-inductance of the magnetic poles in the dipole changes, the impedance of the dipole also changes, the impedance of a coil wound on the magnetic poles in the dipole changes, and the position of the rotor can be represented through the change condition of the voltage of an output node caused by the change.

Optionally, in the same inductance detection branch, the number of the inductances in the first inductance detection group is the same as the number of the inductances in the second inductance detection group, so that the inductances are symmetrically distributed on the inductance sensor, and the position of the rotor can be determined more accurately.

Optionally, the total impedance of the inductor in the first inductor detection group is the same as the total impedance of the inductor in the second inductor detection group, so that when the rotor H displaces, the total impedance of the inductor in the first inductor detection group and the total impedance of the inductor in the second inductor detection group can have the same variation trend, and thus the actual position of the rotor H can be determined through the variation of the impedance, and the position of the rotor H can be determined more conveniently.

Optionally, the structure of the inductor in the first inductor detection group is the same as that of the inductor in the second inductor detection group. Therefore, the inductors can be strictly and symmetrically distributed on the inductive sensor, and the design of the inductive sensor is facilitated to be simplified.

Based on the same inventive concept, embodiments of the present invention further provide a sensor detection circuit applied to a magnetic levitation motor, where the sensor detection circuit applied to the magnetic levitation motor includes the sensor bridge circuit applied to the magnetic levitation motor according to any embodiment of the present invention, and therefore the sensor detection circuit applied to the magnetic levitation motor provided by the embodiments of the present invention includes technical features of the sensor bridge circuit applied to the magnetic levitation motor provided by any embodiment of the present invention, and can achieve beneficial effects of the sensor bridge circuit applied to the magnetic levitation motor provided by any embodiment of the present invention, and the same points can be referred to the above description, and are not repeated.

In an alternative embodiment, fig. 15 is a schematic structural diagram of a sensor detection circuit provided in an embodiment of the present invention, as shown in fig. 15, the sensor detection circuit includes a sensor bridge circuit 200 and at least one signal processing circuit 300 in one-to-one correspondence with at least one inductance detection branch pair 10 in the sensor bridge circuit 200; the signal processing circuit 300 is configured to obtain potentials of output nodes (N1 and N2) of two inductance detection branches in the corresponding pair 10 of inductance detection branches, and output a detection signal.

For example, taking that the sensor bridge circuit 200 includes an inductance detection branch pair 10, and the inductance detection branch pair 10 includes two inductance detection branches 11, and each inductance detection branch includes two inductances, for example, an inductance L1 and an inductance L2 of one inductance detection branch 11 are electrically connected to the output node N1, and an inductance L3 and an inductance L4 of the other inductance detection branch 11 are electrically connected to the output node N2, at this time, the signal processing circuit 300 may obtain potentials of the output node N1 and the output node N2, respectively, so as to determine a position of a rotor in the magnetic levitation motor according to a voltage difference between the output node N1 and the output node N2.

It is to be understood that fig. 15 is only an exemplary diagram of the embodiment of the present invention, fig. 15 only illustrates the structure of the sensor bridge circuit by way of example, and the sensor bridge circuit mentioned for any embodiment of the present invention may be used in addition to the sensor bridge circuit illustrated in fig. 15, and will not be described one by one here. For the convenience of describing the embodiment of the present invention, the sensor bridge circuit includes an inductance detecting branch pair as an example, and the technical solution of the embodiment of the present invention is exemplarily described.

Optionally, with continued reference to fig. 15, the signal processing circuit 300 includes at least one operational amplifier U in one-to-one correspondence with at least one pair of inductance detection branches 10; the non-inverting input end and the inverting input end of the operational amplifier U are respectively and electrically connected with two output nodes N1 and N2 in the same inductance detection branch pair 10; the output end of the operational amplifier U is used for outputting a detection signal.

Therefore, the operational amplifier U can amplify the differential signals of the two output nodes N1 and N2 of the inductance detection branch pair 10 and output corresponding detection signals, and the detection sensitivity is further improved. The operational amplifier U may further include a first power signal terminal and a second power signal terminal to receive the first power signal V1 and the second power signal V2, respectively, so that the operational amplifier U can operate normally.

Optionally, fig. 16 is a schematic structural diagram of another sensor detection circuit provided in an embodiment of the present invention, and based on the above embodiment, the sensor detection circuit further includes a first isolation circuit 400, where the first isolation circuit 400 is electrically connected between the sensor bridge circuit 200 and the excitation source AC. The first isolation circuit 400 can prevent the direct current signal at the AC side of the excitation signal source from affecting the electrical signal at the output node of the sensor bridge circuit 200, so as to further improve the signal-to-noise ratio and the anti-interference capability of the sensor detection circuit, and further improve the sensitivity of signal detection.

In an alternative embodiment, with continued reference to fig. 16, the first isolation circuit 400 may include an isolation capacitor C1; a first end of the isolation capacitor C1 is electrically connected to a first end of the excitation source AC, and a second end of the isolation capacitor C1 is electrically connected to the first inductance detection set 101 of each inductance detection branch 11. At this time, the isolation capacitor C1 not only has a blocking function, but also can form a resonant circuit with an inductor in the sensor bridge circuit to improve the signal-to-noise ratio, thereby being beneficial to improving the detection sensitivity of the sensor detection circuit.

Optionally, fig. 17 is a schematic structural diagram of another sensor detection circuit provided in the embodiment of the present invention, and as shown in fig. 17, the first isolation circuit 400 further includes a first transformer TX1; the first transformer TX1 includes a first primary coil TX11 and a first secondary coil TX12; a first end of the first primary coil TX11 is electrically connected to a second end of the isolation capacitor C1, and a second end of the first primary coil TX11 is electrically connected to a second end of the excitation source AC; a first end of the first secondary coil TX12 is electrically connected to the first inductance detection group 101 of each inductance detection branch, and a second end of the first secondary coil TX12 is electrically connected to the second inductance detection group 102 of each inductance detection branch.

If the excitation inductance of the first transformer TX1 is LTX1, and the total impedance of the inductances of the first inductance detection group 101 and the total impedance of the inductances of the second inductance detection group 102 in each detection branch are both L0, LTX1 > L0 should be used, in a preferred embodiment, LTX1 is greater than or equal to 5 × L0, and at this time, the first transformer TX1 may be an approximately ideal transformer. The turn ratio between the first primary coil TX11 and the first secondary coil TX12 of the first transformer TX1 may be designed according to a gain requirement, which is not specifically limited in the embodiment of the present invention. The first transformer TX1 can further reduce the interference of the AC side of the excitation signal source to the sensor bridge circuit 200, so as to further improve the signal-to-noise ratio and the interference rejection, and further improve the detection accuracy and sensitivity.

It is to be understood that the structure of the first isolation circuit is not limited to the structures shown in fig. 16 to 18, and may also be other devices capable of transmitting high-frequency alternating signals, and the structure of the first isolation circuit is not particularly limited in the embodiments of the present invention on the premise that the isolation function can be achieved.

Optionally, fig. 18 is a schematic structural diagram of another sensor detection circuit provided in an embodiment of the present invention, and as shown in fig. 18, on the basis of the above embodiment, the sensor detection circuit further includes at least one resonant capacitor C2 in one-to-one correspondence with at least one inductance detection branch pair 10, and the resonant capacitor C is electrically connected between output nodes (N1 and N2) of two inductance detection branches 11 in the same inductance detection branch pair 10.

Thus, by arranging the resonant capacitor C2 between the output nodes N1 and N2, the resonant capacitor C2 and the inductors (L1, L2, L3, and L4) in the sensor bridge circuit can respectively form a resonant circuit, so that the signal processing circuit 300 determines the position of the rotor in the magnetic levitation motor according to the resonant signal of the resonant circuit; meanwhile, the resonant capacitor C2 is electrically connected between the output nodes N1 and N2, so that all inductors (L1, L2, L3 and L4) in the sensor bridge circuit and the resonant capacitor C2 can form a resonant circuit, and a capacitor is not required to be configured for each inductor, so that the circuit structure can be simplified, and the circuit matching difficulty is reduced.

Optionally, fig. 19 is a schematic structural diagram of another sensor detection circuit provided in an embodiment of the present invention, and as shown in fig. 20, on the basis of the above embodiment, the sensor detection circuit further includes second isolation circuits 500 electrically connected to at least one signal processing circuit 300 in a one-to-one correspondence, and the second isolation circuits 500 are electrically connected between the output nodes (N1 and N2) of the corresponding pair of inductance detection branches 10 and the signal processing circuit 300. Among them, the second isolation circuit 500 can directly extract the differential mode signal from the sensor bridge circuit 200, and can greatly reduce the requirement for the common mode input voltage range in the operational amplifier U in the signal processing circuit 300, and reduce the influence of the common mode interference on the output detection signal.

Optionally, with continued reference to fig. 19, the second isolation circuit 500 includes a second transformer TX2; the second transformer TX2 includes a second primary coil TX21 and a second secondary coil TX22; two ends of the second primary coil TX21 are electrically connected to two output nodes N1 and N2 of the same inductance detection branch pair 10, respectively; both ends of the second secondary coil TX22 are electrically connected to the signal processing circuit 300, respectively. At this time, the second transformer TX2 can directly take out the differential mode signal from the sensor bridge circuit 200, so that the requirement for the common mode input voltage range of the operational amplifier U of the signal processing circuit 300 is greatly reduced, i.e., the influence of the common mode interference on the detection signal can be reduced, so that the operational amplifier U only needs a common amplifier, does not need a specific differential amplifier, and does not need a specific instrument amplifier, a processor, etc., and can realize the signal processing function and output the corresponding detection signal, thereby further simplifying the matching difficulty of the circuit, and being beneficial to the low cost of the circuit.

When the excitation inductance of the second transformer TX2 is LTX2, and the impedance of the inductance detection branch to each inductance in 10 is L0, LTX2 > L0 should be set, and in a preferred embodiment, LTX2 > 5 × L0, and then the second transformer TX2 may be an approximately ideal transformer. The turn ratio between the first primary coil TX11 and the first secondary coil TX12 of the first transformer TX1 may be designed according to a gain requirement, which is not specifically limited in the embodiment of the present invention.

In fig. 19, the resonant capacitor C2 is electrically connected to the second secondary coil TX22 in the second transformer TX2, that is, the first end of the resonant capacitor C2 is electrically connected to the first end of the second secondary coil TX22, and the second end of the resonant capacitor C2 is electrically connected to the second end of the second secondary coil TX 22. In the embodiment of the present invention, the resonant capacitor may also be electrically connected to the second primary coil of the second transformer.

Illustratively, referring to fig. 20, a first terminal of the resonant capacitor C2 is electrically connected to a first terminal of the second primary coil TX21, and a second terminal of the resonant capacitor C2 is electrically connected to a second terminal of the second primary coil TX 21. At this time, the resonant circuit formed by the resonant capacitor C2 and the inductance in each inductance detection branch 11 is not affected by the excitation inductance of the second transformer TX 2.

It is understood that, in the embodiment of the present invention, the sensor detection circuit may include both the first isolation circuit and the second isolation circuit, may also include only the first isolation circuit, or only the second isolation circuit, which may be designed according to actual needs, and this is not specifically limited in the embodiment of the present invention.

Based on the same inventive concept, the embodiment of the invention also provides a position detection sensor of the magnetic suspension motor, and the position detection sensor of the magnetic suspension motor comprises the sensor detection circuit of the magnetic suspension motor provided by the embodiment of the invention. Therefore, the position detection sensor of the magnetic suspension motor includes technical features of the sensor detection circuit of the magnetic suspension motor provided by the embodiment of the present invention, and can achieve beneficial effects of the sensor detection circuit of the magnetic suspension motor provided by the embodiment of the present invention, and the same points can be referred to the description of the sensor detection circuit of the magnetic suspension motor provided by the embodiment of the present invention, and are not repeated herein.

Based on the same inventive concept, the embodiment of the invention also provides a magnetic suspension motor, and the position detection sensor of the magnetic suspension motor provided by the embodiment of the invention is integrated in the magnetic suspension motor. Therefore, the magnetic levitation motor includes technical features of the position detection sensor of the magnetic levitation motor provided in the embodiment of the present invention, that is, includes technical features of the sensor detection circuit of the magnetic levitation motor provided in the embodiment of the present invention, and can achieve beneficial effects of the sensor detection circuit of the magnetic levitation motor provided in the embodiment of the present invention, and the same points can be referred to the description of the sensor detection circuit of the magnetic levitation motor provided in the embodiment of the present invention, and are not repeated here again.

The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sensor bridge circuit for a magnetically levitated motor, comprising:

2. Sensor bridge circuit of a magnetic levitation motor as claimed in claim 1, wherein the magnetic levitation motor comprises a rotor and a stator, the rotor being displaced in axial and/or radial direction of the stator;

the at least one pair of inductance detection branches comprises:

at least one first pair of inductance sensing branches; in the first inductance detection branch circuit pair, the inductance of the first inductance detection group and the inductance of the second inductance detection group of the same inductance detection branch circuit are arranged and symmetrically arranged along the radial direction;

and/or, at least one second pair of inductance sensing branches; and in the second inductance detection branch circuit pair, the same inductance of the first inductance detection group of the inductance detection branch circuit and the inductance of the second inductance detection group are arranged and symmetrically arranged along the axial direction.

3. The sensor bridge circuit for magnetic levitation motors as recited in claim 2, wherein when the inductances of the first inductance detection group and the second inductance detection group of the same inductance detection branch are arranged and symmetrically disposed along the radial direction, the center line of the inductance of the first inductance detection group and the center line of the inductance of the second inductance detection group in the same inductance detection branch are the same first line extending along the radial direction, and the symmetry axis of the inductance of the first inductance detection group and the inductance of the second inductance detection group is the first symmetry axis extending along the radial direction;

the first straight line is perpendicular to the first symmetry axis and passes through the circle center of the stator.

4. The sensor bridge circuit for a magnetic levitation motor as recited in claim 2, wherein if said at least one pair of inductance detecting branches comprises said first pair of inductance detecting branches, when the distance of the rotor in the radial direction from the rotor radial ideal working position is 0, the potential difference between the output nodes of the two inductance detecting branches of the same first pair of inductance detecting branches is 0V.

5. The sensor bridge circuit for a magnetic levitation motor as recited in claim 2, wherein when the at least one inductance detecting branch pair comprises the first inductance detecting branch pair, the inductances in the first inductance detecting branch pair are sequentially arranged along a circumferential direction of the stator, and a distance between any two adjacent inductances is a fixed value.

6. The sensor bridge circuit for a magnetic levitation motor as recited in claim 2, wherein the first pair of inductance sensing branches are arranged along the circumference of the stator and the angle between the center lines of any two adjacent inductances is 20 ° -30 °.

7. The sensor bridge circuit for a magnetic levitation motor as recited in claim 2, wherein if said at least one pair of inductive detection branches comprises said second pair of inductive detection branches, when the distance of the rotor in the axial direction from an axial ideal working position is 0, the potential difference between the output nodes of the two inductive detection branches of the same second pair of inductive detection branches is 0V.

8. The sensor bridge circuit of a magnetic levitation motor as recited in claim 2, wherein the stator comprises a first substrate, a second substrate and a third substrate arranged in sequence along the axial direction;

if the at least one inductance detection branch pair includes the first inductance detection branch pair and the second inductance detection branch pair, the inductors of the first inductance detection branch pair are arranged along the circumferential direction of the second substrate, and the inductors of one of the inductance detection groups in the inductance detection branch of the second inductance detection branch pair are arranged along the circumferential direction of the first substrate, and the inductors of the other inductance detection group are arranged along the circumferential direction of the third substrate.

9. The sensor bridge circuit for a magnetic levitation motor as recited in claim 1, wherein the inductor comprises an inductor coil and a magnetic can for forming a magnetic field loop of the inductor coil.

10. The sensor bridge circuit for a magnetic levitation motor as recited in claim 1, wherein the inductor comprises a non-zero even number of adjacent magnetic poles and an inductor winding wound around each of the magnetic poles, the non-zero even number of adjacent inductor windings paired to form an inductor winding pair; the two inductance coils of each inductance coil pair are connected in series; the two magnetic poles of each inductance coil pair have opposite polarities and are used for forming a magnetic field loop of the inductance coil pair.

11. The sensor bridge circuit for a magnetic levitation motor as recited in claim 1, wherein the number of inductances in the first inductance detection group is the same as the number of inductances in the second inductance detection group in the same inductance detection branch.

12. The sensor bridge circuit for a magnetic levitation motor as recited in claim 1, wherein the total impedance of the inductors in the first inductance sensing set is the same as the total impedance of the inductors in the second inductance sensing set.

13. The sensor bridge circuit of a magnetic levitation motor as recited in claim 1, wherein the structure of the inductors of the first inductance sensing set is the same as the structure of the inductors of the second inductance sensing set.

14. A sensor detection circuit for a magnetically levitated motor, comprising:

sensor bridge circuit of a magnetic levitation motor as claimed in any one of claims 1 to 13;

at least one signal processing circuit which is in one-to-one correspondence with at least one inductance detection branch in a sensor bridge circuit of the magnetic suspension motor; each signal processing circuit is used for acquiring the electric potential of the output node of two inductance detection branches in the corresponding inductance detection branch pair and outputting a detection signal.

15. The sensor detection circuit of a magnetic levitation motor as recited in claim 14, further comprising:

a first isolation circuit electrically connected between the sensor bridge circuit and the excitation source.

16. The sensor detection circuit of a magnetic levitation motor as recited in claim 15, wherein the first isolation circuit comprises an isolation capacitor; the first end of the isolation capacitor is electrically connected with the first end of the excitation source, and the second end of the isolation capacitor is electrically connected with the first inductance detection group of each inductance detection branch circuit.

17. The sensor detection circuit of a magnetic levitation motor as recited in claim 16, wherein the first isolation circuit further comprises a first transformer; the first transformer comprises a first primary coil and a first secondary coil;

the first end of the first primary coil is electrically connected with the second end of the isolation capacitor, and the second end of the first primary coil is electrically connected with the second end of the excitation source; the first end of the first secondary coil is electrically connected with the first inductance detection group of each inductance detection branch circuit, and the second end of the first secondary coil is electrically connected with the second inductance detection group of each inductance detection branch circuit.

18. The sensor detection circuit of a magnetic levitation motor as recited in claim 17, wherein the excitation inductance of the first transformer is LTX1, and the impedance of the inductance in the inductance detection branch is L0; wherein LTX1 > L0.

19. The sensor detection circuit of a magnetic levitation motor as recited in claim 14, further comprising:

and the at least one resonance capacitor is in one-to-one correspondence with the at least one inductance detection branch circuit pair and is electrically connected between the output nodes of the two inductance detection branch circuits in the same inductance detection branch circuit pair.

20. The sensor detection circuit of a magnetic levitation motor as recited in claim 19, further comprising:

and the second isolation circuits are electrically connected between the output nodes of the corresponding inductance detection branch circuit pairs and the signal processing circuits in a one-to-one correspondence manner.

21. The sensor detection circuit of a magnetic levitation motor as recited in claim 20, wherein the second isolation circuit comprises a second transformer; the second transformer comprises a second primary coil and a second secondary coil;

two ends of the second primary coil are respectively and electrically connected with two output nodes of the same inductance detection branch circuit pair; and two ends of the second secondary coil are respectively and electrically connected with the signal processing circuit.

22. The sensor detection circuit of a magnetic levitation motor as recited in claim 21, wherein a first end of the resonant capacitor is electrically connected to a first end of the second primary coil and a second end of the resonant capacitor is electrically connected to a second end of the second primary coil;

or the first end of the resonant capacitor is electrically connected with the first end of the second secondary coil, and the second end of the resonant capacitor is electrically connected with the second end of the second secondary coil.

23. The sensor detection circuit of a magnetic levitation motor as recited in claim 21, wherein the excitation inductance of the second transformer is LTX2, and the impedance of the inductance in the inductance detection branch is L0; wherein LTX2 > L0.

24. The sensor detection circuit of a magnetic levitation motor as recited in claim 14, wherein the signal processing circuit comprises at least one operational amplifier in one-to-one correspondence with at least one of the inductance detection branch pairs;

the non-inverting input end and the inverting input end of the operational amplifier are respectively and electrically connected with two output nodes in the same inductance detection branch pair; the output end of the operational amplifier is used for outputting the detection signal.

25. A position detection sensor of a magnetic levitation motor, comprising: sensor detection circuit of a magnetic levitation motor as claimed in any of the claims 14-24.

26. A magnetically levitated motor characterized in that it is integrated with a position detection sensor of the magnetically levitated motor of claim 25.