WO2016188330A1

WO2016188330A1 - Shaft position detection device and magnetic levitation motor

Info

Publication number: WO2016188330A1
Application number: PCT/CN2016/082014
Authority: WO
Inventors: 胡余生; 郭伟林; 贺永玲; 牛高产; 胡叨福; 李燕
Original assignee: 珠海格力电器股份有限公司
Priority date: 2015-05-27
Filing date: 2016-05-13
Publication date: 2016-12-01
Also published as: CN105066857B; CN105066857A

Abstract

A shaft position detection device and magnetic levitation motor, comprising: an eddy current displacement sensor probe (201) and an integrated proximitor (202) connected thereto, wherein the eddy current displacement sensor probe (201) comprises ten or more eddy current displacement sensor probe heads (2011), and two or more of the eddy current displacement sensor probe heads (2011) are provided to sense each of five degrees of freedom of a magnetic levitation motor shaft. The embodiments of the invention can efficiently save a space and facilitate device integration.

Description

Axis position detecting device and magnetic levitation motor

The present application claims priority to Chinese Patent Application No. 201510282490.3, entitled "Axis Position Detection Device and Magnetic Suspension Motor", which is incorporated herein by reference. .

Technical field

The invention relates to the field of detection technology, in particular to a shaft position detecting device and a magnetic levitation motor.

Background technique

In the magnetic levitation motor, it is necessary to detect a displacement signal of 5 degrees of freedom of the shaft, and the displacement signals of the five degrees of freedom are used to be supplied to the bearing controller to realize stable suspension control of the shaft. At least one non-contact displacement sensor is required for each degree of freedom to measure the shaft displacement.

In order to improve the suspension accuracy, in the current technology, a differential structure is usually adopted, that is, two non-contact displacement sensors are installed for each degree of freedom, and a total of 10 non-contact displacement sensors are required in the whole magnetic suspension bearing system, and the non-contact type is used. The displacement sensor generally uses an eddy current displacement sensor. In the current technology, referring to FIG. 1, the design of the eddy current displacement sensor (ie, the shaft position detecting device) generally adopts a discrete design scheme, that is, one probe corresponds to one preamplifier circuit.

However, in the current technical solution, since each probe corresponds to one preamplifier circuit, the volume of the preamplifier is large, which is not conducive to integration.

Summary of the invention

In view of this, the present invention provides a shaft position detecting device and a magnetic levitation motor which are small in size and convenient for integration.

To achieve the above object, the present invention provides the following technical solutions:

A shaft position detecting device comprising:

An eddy current displacement sensor probe set, and an integrated front end connected to the eddy current displacement sensor probe set;

The eddy current displacement sensor probe set includes at least 10 eddy current displacement sensor probes, and at least two of the eddy current displacement sensor probes are provided for each degree of freedom in five degrees of freedom of the magnetic levitation motor shaft.

Preferably, the eddy current displacement sensor probe set is integrated in two probe rings, and the two probe rings are respectively disposed at two ends of the shaft.

Preferably, the eddy current displacement sensor probe corresponding to the same degree of freedom of the magnetic levitation motor shaft adopts a differential arrangement structure.

Preferably, the integrated front end device comprises:

An excitation source generating circuit connected to the eddy current displacement sensor probe set; a resonant capacitor corresponding to each of the eddy current displacement sensor probes, each of the eddy current displacement sensor probes being connected in parallel with a corresponding resonant capacitor Constituting at least 10 sets of resonant circuits, wherein each degree of freedom of the magnetic levitation motor shaft corresponds to at least two sets of resonant circuits; at least 5 sets of differential detecting circuits, each degree of freedom of the magnetic levitation motor shaft corresponding to at least one set of differential detection a circuit, the differential detection circuit of the same degree of freedom is connected to the corresponding resonant circuit; and at least 5 sets of amplification filter circuits, each degree of freedom of the magnetic levitation motor shaft corresponding to at least one set of amplification filter circuits, the same freedom The amplification filter circuit of the degree is connected to the corresponding differential detection circuit.

Preferably, the excitation source generating circuit is a square wave excitation source generating circuit.

Preferably, the differential detection circuit comprises:

a signal selection circuit and a differential circuit coupled to the signal selection circuit.

Preferably, the integrated front end is disposed on a bearing controller of the magnetic levitation motor.

Preferably, all of the eddy current displacement sensor probes are eddy current displacement sensor probes whose electrical parameters and mechanical parameters are all the same respectively; all of the resonant capacitors are capacitors having the same parameter.

Preferably, all of the resonant circuits are resonant circuits having a natural oscillation frequency equal to the frequency of the excitation signal, and the excitation signal is generated by the excitation source generating circuit.

A magnetic levitation motor comprising:

The magnetic levitation motor body, and the shaft position detecting device according to any one of the above.

According to the above technical solution, the present invention provides a shaft position detecting device and a magnetic levitation motor as compared with the prior art. The shaft position detecting device comprises: an eddy current displacement sensor probe set, and an integrated front end connected to the eddy current displacement sensor probe set; the eddy current displacement sensor probe set includes at least 10 eddy current displacement sensor probes, In the five degrees of freedom of the magnetic levitation motor shaft, at least two of the eddy current displacement sensor probes are provided for each degree of freedom. The technical solution provided by the invention provides an integrated front-end device, and the integrated front-end device occupies a small volume, and can effectively save space and convenience compared with the scheme of corresponding one-stage circuit of each probe in the prior art. Integrated.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can obtain other drawings according to the provided drawings without any creative work.

1 is a structural view of a shaft position detecting device in the prior art;

2 is a structural diagram of a shaft position detecting device according to an embodiment of the present invention;

3 is a structural diagram of another shaft position detecting device according to an embodiment of the present invention;

4 is a structural diagram of a differential arrangement of an eddy current displacement sensor probe according to an embodiment of the present invention;

FIG. 5 is a structural diagram of an integrated front end device according to an embodiment of the present invention; FIG.

6 is a structural diagram of a differential detection circuit in an integrated preamplifier according to an embodiment of the present invention;

FIG. 7 is a waveform diagram of differential detection according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of them. Example. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Please refer to FIG. 1. FIG. 1 is a structural diagram of a shaft position detecting device in the prior art. As shown in FIG. 1, the prior art shaft position detecting device generally adopts a discrete design scheme, that is, one probe corresponds to one preamplifier circuit. In the prior art, the discrete technical solution has a large volume of the preamplifier due to the corresponding preamplifier circuit of each probe, which is disadvantageous for integration.

To this end, the present invention provides a new shaft position detecting device for solving the above-mentioned problem of inconvenience in integration in the prior art.

Example

Please refer to FIG. 2. FIG. 2 is a structural diagram of a shaft position detecting device according to an embodiment of the present invention. As shown in FIG. 2, the shaft position detecting device provided by the embodiment of the present invention includes:

An eddy current displacement sensor probe set 201, and an integrated front end device 202 connected to the eddy current displacement sensor probe set 201;

The eddy current displacement sensor probe set 201 includes at least ten eddy current displacement sensor probes 2011, and at least two of the eddy current displacement sensor probes 2011 are provided for each degree of freedom in five degrees of freedom of the magnetic levitation motor shaft.

Specifically, the shaft position detecting device provided by the embodiment of the present invention optionally includes 10 eddy current displacement sensor probes 2011. In the five degrees of freedom of the magnetic levitation motor shaft, each of the degrees of freedom is set with two of the electric powers. Eddy current displacement sensor probe 2011. Of course, in the shaft position detecting device provided by the embodiment of the present invention, in the five degrees of freedom of the magnetic levitation motor shaft, more than two eddy current displacement sensor probes 2011 may be set in any one degree of freedom, for example, four (required An even number of the eddy current displacement sensor probes 2011. It should be noted that, in the five degrees of freedom of the magnetic levitation motor shaft, two eddy current displacement sensor probes 2011 are provided for each degree of freedom, which is actually sufficient.

Specifically, in the shaft position detecting device provided by the embodiment of the present invention, the eddy current displacement sensor probe 2011 corresponding to the same degree of freedom of the magnetic levitation motor shaft adopts a differential arrangement structure, that is, the magnetic levitation motor shaft has the same degree of freedom. The eddy current displacement sensor probe 2011 corresponding to other degrees of freedom exists between the corresponding eddy current displacement sensor probes 2011.

Please refer to FIG. 3. FIG. 3 is a structural diagram of another shaft position detecting device according to an embodiment of the present invention. As shown in FIG. 3, the eddy current displacement sensor probe set is integrated in two probe rings 203, that is, the eddy current displacement sensor probes 2011 are distributed in two probe rings 203, specifically, optionally, wherein One probe ring 203 integrates four of the eddy current displacement sensor probes 2011 with two degrees of freedom, and the other probe ring 203 integrates six of the eddy current displacement sensor probes 2011 with three degrees of freedom. The two probe rings 203 are respectively disposed at both ends of the shaft and are not in contact with the shaft.

Further, please refer to FIG. 4. FIG. 4 is a structural diagram of a differential arrangement of an eddy current displacement sensor probe according to an embodiment of the present invention. As shown in Figure 4, the X1 probe and the X2 probe are two eddy current displacement sensor probes of the same degree of freedom, and the Y1 probe and the Y2 probe are two eddy current displacement sensor probes of another degree of freedom, visible, two of the same degree of freedom. An eddy current displacement sensor probe, such as an X1 probe and an X2 probe, is differentially arranged. In the figure, the area between the shaft and the probe ring is a gap between the two, and the two are non-contact structures.

Specifically, please refer to FIG. 5. FIG. 5 is a structural diagram of an integrated front end device according to an embodiment of the present invention. As shown in FIG. 5, the integrated front end device 202 includes:

An excitation source generating circuit 2021 connected to the eddy current displacement sensor probe set; a resonance capacitor C corresponding to each of the eddy current displacement sensor probes 2011, each corresponding to the eddy current displacement sensor probe 2011 The resonant capacitors C are connected in parallel to form at least 10 sets of resonant circuits 2022, wherein each degree of freedom of the magnetic levitation motor shaft corresponds to at least two sets of resonant circuits 2022; at least five sets of differential detecting circuits 2023, each of the magnetic levitation motor shafts The degree of freedom corresponds to at least one set of differential detection circuits 2023, the differential detection circuit 2023 of the same degree of freedom is connected to the corresponding resonance circuit 2022, and at least five sets of amplification filter circuits 2024, each of the magnetic suspension motor axes The degree of freedom corresponds to at least one set of amplification filter circuits 2024, and the amplification filter circuit 2024 of the same degree of freedom is connected to the corresponding differential detection circuit 2023.

Further, in order to more clearly explain the structure of the integrated front end device 202, the following description will continue with the ten eddy current displacement sensor probes 2011 included in the shaft position detecting device of the present invention. Referring to FIG. 5, in FIG. 5, other circuit parts except the excitation source generating circuit 2021 and the ellipsis are for a certain degree of freedom structure, such as a first degree of freedom axis position detecting circuit, and an ellipsis part indicating the other 4 The axis position detecting circuit of one degree of freedom is exactly the same as the structure of the first degree of freedom axis position detecting circuit, and the five-degree-of-freedom axis position detecting circuit is connected to the excitation source generating circuit 2021 to receive the excitation thereof. signal. If there are two more probes in one degree of freedom, the same detection circuit as the first degree of freedom axis position detecting circuit is provided for the two extra probes, and the detection is set for the two extra probes. The circuit is also coupled to the excitation source generating circuit 2021 to receive its excitation signal.

The differential signal of the two eddy current displacement sensor probes on the same degree of freedom is differentially detected, and the amount related only to the displacement change is extracted. Since the amplitude of the signal is small, the amplification factor of the latter stage can be correspondingly increased. Therefore, the sensitivity can be improved, and the filter capacitor can be selected to be smaller, thereby improving the frequency response. In addition, since the influence of temperature on the parameters of the two probes on the same degree of freedom is uniform, the difference between the two can be removed. The effect of the change on the sensor signal, thereby improving the temperature drift performance of the sensor.

Further, in the shaft position detecting device provided by the embodiment of the present invention, the excitation source generating circuit 2021 is a square wave excitation source generating circuit. Square wave excitation source generating circuit relative to sine in the prior art The wave excitation source generating circuit has a simple circuit structure and a small volume.

Further, please refer to FIG. 6. FIG. 6 is a structural diagram of a differential detection circuit in an integrated preamplifier according to an embodiment of the present invention. As shown in FIG. 6, the axis position detecting device provided by the embodiment of the present invention, the differential detecting circuit 2023 includes:

A signal selection circuit 20231 and a differential circuit 20232 connected to the signal selection circuit 20231.

Specifically, referring to FIG. 6, the previous radial X direction is taken as an example to illustrate the process of differential detection. The eddy current displacement sensor probe X1 resonance signal (referred to as PX1) and the eddy current displacement sensor probe X2 resonance signal (referred to as PX2) are selected by signals. The circuit 20231 obtains two signals PX+ and PX-. The waveform of PX+ is composed of the positive half-cycle waveform of PX1 and the negative half-cycle waveform of PX2. The waveform of PX- consists of the negative half-cycle waveform of PX1 and the positive half-cycle waveform of PX2, and then the difference. The circuit 20232 converts the PX+ minus the PX- to achieve a difference, and obtains a signal PXA related only to the displacement change amount, that is, the PXA is a signal for differential detection of both the eddy current displacement sensor probe X1 and the eddy current displacement sensor probe X2, as shown in FIG. FIG. 7 is a waveform diagram of differential detection according to an embodiment of the present invention, wherein the horizontal axis represents time and the vertical axis represents voltage. The polarity of the PXA signal is related to the position of the axis. When the axis is close to the eddy current displacement sensor probe X1 away from the eddy current displacement sensor probe X2, the amplitude of PX1 is smaller than the amplitude of PX2, and the PXA signal is negative, otherwise, the PXA signal Positive. The PXA signal is a pulsation signal, which is amplified and filtered by the amplification filter circuit 2024 to obtain a DC signal PXD corresponding to the position. PXD is also negative when the PXA signal is negative, and PXD is also positive when the PXA signal is positive. Since the analog-to-digital conversion chip generally only recognizes the positive signal, the PX signal is obtained by adding an appropriate bias voltage to the PXD signal through a bias circuit, so that the voltage of the PX is within the minimum and maximum values of the analog-to-digital conversion chip acquisition range. This finally results in a voltage signal PX that is proportional to the change in displacement.

Specifically, optionally, the shaft position detecting device provided by the embodiment of the present invention is disposed on a bearing controller of the magnetic levitation motor.

Further, in the shaft position detecting device provided by the embodiment of the present invention, all of the eddy current displacement sensor probes are eddy current displacement sensor probes whose electrical parameters and mechanical parameters are all the same respectively; all of the resonant capacitors are capacitors having the same parameter.

Further, the shaft position detecting device provided by the embodiment of the present invention is provided in the integrated front end device. The resonant circuit is a resonant circuit having a natural oscillation frequency equal to the frequency of the excitation signal, and the excitation signal is generated by the excitation source generating circuit. When the measured body is close to the eddy current displacement sensor probe, the equivalent impedance of the eddy current displacement sensor probe changes, the resonant circuit is detuned, the output voltage also changes, and the closer the measured object is to the eddy current displacement sensor probe, the detuning The larger the output voltage, the smaller the output voltage. The output signal of the LC resonant circuit is a sine wave, and the change of its amplitude reflects the change of the distance of the measured body from the eddy current displacement sensor probe.

Further, the present invention also discloses a magnetic levitation motor comprising the magnetic levitation motor body, and the shaft position detecting device disclosed in the above embodiment of the present invention.

In addition, according to the technical solution provided by the present invention, all the eddy current displacement sensor probes use a unified excitation source to improve the consistency of the signals of the eddy current displacement sensors, simplify the circuit, and eliminate the use of multiple excitation source probes between each other. interference.

In addition, the technical solution provided by the invention adopts the differential detection method to improve the sensitivity and the frequency response, and can remove the influence of the temperature change on the sensor signal, thereby improving the temperature drift performance of the sensor.

Finally, it should also be noted that in this context, relational terms such as first and second are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these entities. There is any such actual relationship or order between operations. Furthermore, the term "comprises" or "comprises" or "comprises" or any other variations thereof is intended to encompass a non-exclusive inclusion, such that a process, method, article, or device that comprises a plurality of elements includes not only those elements but also Other elements, or elements that are inherent to such a process, method, item, or device. An element that is defined by the phrase "comprising a ..." does not exclude the presence of additional equivalent elements in the process, method, item, or device that comprises the element.

The various embodiments in the present specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same similar parts between the various embodiments may be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but the scope of the invention is to be accorded

Claims

A shaft position detecting device, comprising:

An eddy current displacement sensor probe set, and an integrated front end connected to the eddy current displacement sensor probe set;

The eddy current displacement sensor probe set includes at least 10 eddy current displacement sensor probes, and at least two of the eddy current displacement sensor probes are provided for each degree of freedom in five degrees of freedom of the magnetic levitation motor shaft.
The shaft position detecting device according to claim 1, wherein said eddy current displacement sensor probe group is integrated in two probe rings, and said two probe rings are respectively disposed at both ends of the shaft.
The shaft position detecting device according to claim 1, wherein the eddy current displacement sensor probe corresponding to the same degree of freedom of the magnetic levitation motor shaft adopts a differential arrangement structure.
The shaft position detecting device according to claim 1, wherein the integrated front end device comprises:

An excitation source generating circuit connected to the eddy current displacement sensor probe set; a resonant capacitor corresponding to each of the eddy current displacement sensor probes, each of the eddy current displacement sensor probes being connected in parallel with a corresponding resonant capacitor Constituting at least 10 sets of resonant circuits, wherein each degree of freedom of the magnetic levitation motor shaft corresponds to at least two sets of resonant circuits; at least 5 sets of differential detecting circuits, each degree of freedom of the magnetic levitation motor shaft corresponding to at least one set of differential detection a circuit, the differential detection circuit of the same degree of freedom is connected to the corresponding resonant circuit; and at least 5 sets of amplification filter circuits, each degree of freedom of the magnetic levitation motor shaft corresponding to at least one set of amplification filter circuits, the same freedom The amplification filter circuit of the degree is connected to the corresponding differential detection circuit.
The shaft position detecting device according to claim 4, wherein said excitation source generating circuit is a square wave excitation source generating circuit.
The shaft position detecting device according to claim 4, wherein the differential detection circuit comprises:

a signal selection circuit and a differential circuit coupled to the signal selection circuit.
The shaft position detecting device according to claim 4, wherein the integrated front end is disposed on a bearing controller of the magnetic levitation motor.
A shaft position detecting device according to claim 4, wherein all said eddy The flow displacement sensor probe is an eddy current displacement sensor probe in which the electrical parameters and the mechanical parameters are all the same respectively; all of the resonant capacitors are capacitors having the same parameter.
The shaft position detecting device according to claim 8, wherein all of said resonance circuits are resonance circuits having a natural oscillation frequency equal to a frequency of an excitation signal, and said excitation signal is generated by said excitation source generating circuit.
A magnetic levitation motor, comprising:

The magnetic levitation motor body, and the shaft position detecting device according to any one of claims 1-9.