Linear oscillation motor piston stroke induction type additional winding design method

Abstract

The invention belongs to the technical field of motor design and control, and discloses a linear oscillation motor piston stroke induction type additional winding design method, which comprises the following steps of: arranging an additional winding on stator outer teeth of a linear oscillation motor, and starting the additional winding when a working current is introduced into the linear oscillation motor to enable a motor piston to do linear reciprocating motion, permanent magnetic field induced electromotive force is generated in each coil of the additional winding; based on the total permanent magnetic field induced electromotive force generated by superposition of coils of the additional winding, the number of turns of each coil is calculated, the designed additional winding is obtained, and the fundamental wave amplitude of the output voltage of the additional winding corresponds to a piston stroke signal of the linear oscillation motor. The invention further provides a corresponding linear oscillation motor piston stroke observation method and a position-sensorless piston stroke control method of the linear oscillation motor based on the additional winding. According to the invention, the robustness and accuracy of piston stroke observation can be improved while the advantages of small size and high integration level of the linear oscillation motor are kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor design and control, and more specifically, relates to a design method for a piston stroke induction type additional winding of a linear oscillation motor. Background Art

[0002] The refrigeration linear compressor of the linear oscillation motor can reduce friction points, improve efficiency and further reduce the size of the compressor system because it omits the conversion structure such as the crank connecting rod in the middle. The linear oscillation motor is a device that uses springs to achieve forced simple harmonic vibration. It has the characteristic of unlimited piston stroke. If open-loop control is used, it is easy to have the risk of hitting the cylinder, which will seriously damage the compressor. Therefore, stroke closed-loop control is required to control its stroke.

[0003] The use of traditional mechanical position sensors to obtain the stroke signal of the motor will greatly weaken the advantages of small size and high integration that are unique to linear compressors. To this end, there is a method in the prior art that uses the back electromotive force of the main (armature) winding to identify the piston stroke of the motor, and introduces the idea of ​​position sensorless in the rotating motor into the linear oscillation motor. It uses the characteristic that the back electromotive force determined by the parameters of the main winding in the voltage equation contains position information to calculate the back electromotive force, and calculates the speed based on the characteristic that the back electromotive force is proportional to the speed, and then obtains the position of the mover by integrating the speed. Finally, the amplitude of the mover is calculated by Fourier transform and other methods. The amplitude is fed back to the given value as the piston stroke to make a difference, thereby controlling the motor piston stroke. Since the linear oscillation motor is a high-frequency reciprocating motion equipment, the working environment temperature of the linear compressor it constitutes is relatively high, resulting in a large range of variation in the main winding parameters. Therefore, the accuracy of the stroke signal calculated by this method is poor. Summary of the invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a method for designing an additional winding of a linear oscillation motor piston stroke induction type, the purpose of which is to improve the robustness and accuracy of piston stroke observation while retaining the advantages of small size and high integration of the linear oscillation motor.

[0005] To achieve the above object, according to a first aspect of the present invention, a method for designing a piston stroke induction type additional winding of a linear oscillation motor is provided, wherein the linear oscillation motor is a permanent magnet linear oscillation motor with stator external teeth, comprising:

[0006] An additional winding is arranged on the stator outer teeth of the linear oscillation motor, and when a working current is supplied to the linear oscillation motor to make the motor piston perform linear reciprocating motion, a permanent magnetic field induced electromotive force is generated in each coil of the additional winding;

[0007] Based on the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional windingadd , calculate the number of turns N of each coil a , and obtain the designed additional winding; wherein the additional winding output voltage V add Fundamental amplitude V madd The piston stroke signal X of the linear oscillation motor peak Corresponding relationship: X peak =αV madd , α is the back electromotive force coefficient; N a The calculation formula is:

[0008]

[0009] Where m is the total number of coils in the additional winding. represents the permanent magnetic field induced electromotive force of each conductor in the coil, t represents time, V ADC is the maximum value of the microcontroller sampling voltage, and the microcontroller is used to output the additional winding voltage V add Perform A / D sampling to obtain the fundamental amplitude V madd .

[0010] Furthermore, the total number of coils of the additional winding is an even number and is symmetrically distributed on the stator outer teeth of the linear oscillation motor.

[0011] Furthermore, the total number of stator external teeth of the linear oscillation motor is an even number, one coil is arranged on each of the stator external teeth, and each coil constitutes the additional winding.

[0012] Furthermore, the coils of the additional winding are connected in series or in series-parallel to form a superimposed permanent magnetic field induced electromotive force.

[0013] Furthermore, the coils of the additional winding are connected in series through the same-name ends to form the superimposed permanent magnetic field induced electromotive force.

[0014] Furthermore, when the microcontroller samples the maximum value of the voltage V ADC When the voltage exceeds a preset threshold, the linear oscillation motor piston stroke induction type additional winding design method further includes:

[0015] A resistor is connected in series with the additional winding. At this time, the output voltage V add is the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding add The sum of the voltage drops caused by the resistance in series with the additional winding.

[0016] Furthermore, the permanent magnet linear oscillation motor with stator external teeth is a C-type or E-type moving magnet or moving iron linear oscillation motor.

[0017] According to a second aspect of the present invention, there is provided an additional winding designed by the method for designing a piston stroke induction type additional winding of a linear oscillation motor as described in any one of the first aspects.

[0018] According to a third aspect of the present invention, a method for observing the piston stroke of a linear oscillation motor is provided, comprising:

[0019] Arrange an additional winding on the stator outer teeth of the linear oscillation motor; wherein the additional winding is designed by the linear oscillation motor piston stroke induction type additional winding design method described in any one of the first aspects, or is the additional winding described in the second aspect;

[0020] When the linear oscillation motor is supplied with working current to make the motor piston perform linear reciprocating motion, a permanent magnetic field induced electromotive force is generated in each coil of the additional winding, and a microcontroller is used to output a voltage V add Perform A / D sampling to obtain the fundamental amplitude V madd ;

[0021] Based on the fundamental amplitude V madd The piston stroke signal X of the linear oscillation motor peak The corresponding relationship between: X peak =αV madd , get the piston stroke signal X of the linear oscillation motor peak , so as to observe the piston stroke of the linear oscillation motor.

[0022] According to a fourth aspect of the present invention, there is provided a position sensorless piston stroke control method of a linear oscillation motor based on an additional winding, comprising:

[0023] The linear oscillation motor piston stroke observation method described in the third aspect is used to obtain the piston stroke signal of the linear oscillation motor; the piston stroke signal is closed-loop controlled to realize position sensorless piston stroke control of the linear oscillation motor based on the additional winding.

[0024] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0025] (1) The present invention designs an additional winding on the stator outer teeth of the permanent magnet linear oscillation motor. When the working current is passed through the linear oscillation motor, the piston of the linear oscillation motor moves alternately under the action of the permanent magnetic field. The permanent magnetic field can induce an induced electromotive force with periodic frequency alternation in each coil of the additional winding, that is, the induced electromotive force in each coil of the additional winding forms a corresponding relationship with the motor piston. Therefore, the piston stroke signal of the linear oscillation motor can be obtained directly by using the fundamental amplitude of the output voltage of the additional winding to realize the observation of the piston stroke of the linear oscillation motor. The corresponding advantages are as follows: First, the stroke signal is independent of the parameters of the main winding (the original armature winding of the linear oscillation motor). Since the additional winding is designed on the stator outer teeth, it is less affected by heat; and, no additional current is passed through the designed additional winding, so it is not a heat source. When the working environment temperature is high, it has little effect on the piston stroke signal, thereby improving the robustness and accuracy of the piston stroke observation. Secondly, the motor piston stroke observation is performed based on the additional winding designed by the present invention, and no mechanical position sensor is required. This is a position sensor-free piston stroke observation of a linear oscillation motor, which retains the advantages of the linear oscillation motor in terms of small size and high integration. Thirdly, the piston stroke signal is directly obtained, rather than the existing method of first calculating the piston position based on the induced electromotive force of the main winding and then determining the piston stroke based on the piston position, which has the advantage of simple observation.

[0026] (2) Preferably, the total number of coils of the additional winding is an even number and is symmetrically distributed on each outer tooth of the stator to avoid harmonic problems caused by coil asymmetry.

[0027] (3) As a preferred embodiment, the coils of the additional winding are connected in series with the same end, so that the permanent magnetic field induced electromotive force generated in each coil is positively algebraically superimposed (enhanced in the same direction). At this time, the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding is add Compared with the armature magnetic field induced electromotive force in the coil which is approximately 0, the influence of the main winding current on the piston stroke observation can be further reduced, and a high position observation accuracy can be maintained at different main winding current operating points.

[0028] (4) As a preferred embodiment, when the microcontroller samples the maximum value of the voltage V ADC When the voltage exceeds the preset threshold, the maximum value V of the microcontroller sampling voltage ADC When it is larger, the output voltage of the additional winding may be smaller. Therefore, a resistor is connected in series with the additional winding to increase the output voltage, which can adapt to different measurement requirements.

[0029] In general, the present invention solves the problems of bulky system caused by the existing use of mechanical position sensors, as well as poor parameter robustness and low position observation accuracy when the main winding signal is used to identify the stroke signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the design method of the piston stroke induction type additional winding of the linear oscillation motor in the embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of a method for winding an additional winding in an embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of providing an additional winding on an E-type permanent magnet linear oscillation motor with stator external teeth in an embodiment of the present invention;

[0033] Figure 4 For Figure 3 The linear oscillation motor and the additional winding shown are waveform diagrams of the motor piston position and current magnitude under different main winding currents;

[0034] Figure 5 For Figure 3 The Fourier analysis diagram of the motor piston position and current magnitude under different main winding currents on the linear oscillation motor and the additional winding shown;

[0035] Figure 6 A control block diagram of a linear oscillation motor piston stroke induction type additional winding design method provided by an embodiment of the present invention when cooperating with piston stroke control.

[0036] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0037] 1 is the stator core; 2 is the main winding; 3 is the stator permanent magnet; 4 is the mover core; 5 is the mover permanent magnet; 6 is the additional winding. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] Example 1

[0040] like Figure 1 As shown, an embodiment of the present invention provides a method for designing a piston stroke induction type additional winding of a linear oscillation motor, comprising:

[0041] S1. An additional winding is arranged on the stator outer teeth of a permanent magnet linear oscillation motor having stator outer teeth; wherein, when a working current is passed through the linear oscillation motor, an armature magnetic field induced electromotive force and a permanent magnetic field induced electromotive force are generated in each coil of the additional winding under the action of the armature magnetic field and the permanent magnetic field generated by the original armature winding of the linear oscillation motor; since the additional winding is arranged on the stator outer teeth, the armature magnetic field induced electromotive force generated in each coil of the additional winding is much smaller than the permanent magnetic field induced electromotive force, that is, the armature magnetic field induced electromotive force generated in each coil of the additional winding can be expressed as a voltage of approximately 0 to the outside by the additional winding.

[0042] As a specific implementation manner, the permanent magnet linear oscillation motor with stator external teeth may be a C-type or E-type or other moving magnet or moving iron linear oscillation motor topology with stator external teeth.

[0043] S2, based on the total permanent magnetic field induced electromotive force e generated by the superposition of each coil of the additional winding add , calculate the number of turns N of each coil a , the calculation formula is:

[0044]

[0045] Where m is the total number of coils in the additional winding, Φ P is the average magnetic flux of the permanent magnet through one stator outer tooth, represents the permanent magnetic field induced electromotive force of each conductor in each coil, t represents time, V ADC is the maximum value of the microcontroller sampling voltage, which is related to the design parameters of the device itself. The microcontroller is used to output the additional winding voltage V add Perform A / D sampling to obtain the corresponding fundamental amplitude. The output voltage V add It is equal to the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding add Add the voltage drop of the equivalent resistance of the line. Generally speaking, the voltage drop of the equivalent resistance of the line is very small and can be ignored.

[0046] Preferably, the total number of coils of the additional winding is an even number, i.e. m=2k, k>0, and is symmetrically distributed on each external tooth of the stator to avoid harmonic problems caused by coil asymmetry. a The calculation formula can be expressed as:

[0047]

[0048] As a preferred implementation, in an embodiment of the present invention, the number of stator external teeth is an even number, a coil is arranged on each stator external tooth, and the coils together constitute an additional winding.

[0049] Specifically, the coils of the additional winding are connected in series or in series-parallel to form a superimposed permanent magnetic field induced electromotive force. Preferably, the coils of the additional winding are connected in series with the same end, so that the permanent magnetic field induced electromotive force generated in each coil is positively algebraically superimposed (enhanced in the same direction). At this time, the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding is add Compared with the armature magnetic field induced electromotive force which is approximately 0 in the coil, it can reduce the influence of the main winding (the original armature winding of the linear oscillation motor) current on the piston stroke observation, and can maintain a high position observation accuracy at different main winding current operating points.

[0050] S3. Based on the above design, a designed additional winding is obtained, wherein the designed additional winding output voltage fundamental amplitude V madd The piston stroke signal X of the linear oscillation motor peak There is a coefficient correspondence between them, that is: X peak =αV madd , α is the back electromotive force coefficient; wherein, the stroke signal is used to observe the piston stroke of the linear oscillation motor.

[0051] When the microcontroller samples the maximum voltage V ADC When the output voltage of the additional winding is larger, the output voltage of the additional winding may be smaller. A resistor can be connected in series with the additional winding to increase the output voltage to meet different measurement requirements. At this time, the output voltage V add It is equal to the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding add Add the voltage drop V0 of the additional winding series resistance. If the additional winding has no additional series resistance, the output voltage V add Approximately equal to the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding add , correspondingly, the additional winding output voltage V add Fundamental amplitude V madd Approximately equal to e add The fundamental amplitude E madd .

[0052] The additional winding design method in the embodiment of the present invention is applied to an E-type permanent magnet linear oscillation motor with stator external teeth (the motor topology proposed in the application number CN202311826286.4) for verification. Figure 2 The additional windings are connected in series using the same-name end-to-end connection, where the "*" is the same-name end of the coil, that is, the same-name end of the coil is defined as the end where the electromotive force generated by the permanent magnetic field in each coil can be superimposed in the same direction. Figure 3Schematic diagram of arranging additional windings on the stator outer teeth of the motor. The motor includes a stator core 1, a main winding 2, a stator permanent magnet 3, a mover core 4, a mover permanent magnet 5, and an additional winding 6. The number of stator outer teeth of the motor is 4, and the total number of coils of the additional winding 6 is 4. Set V m is the maximum movement speed of the piston of the linear oscillation motor. When the piston (connected to the mover) moves at V m When the speed of cos(wt) is linearly reciprocating (w represents the angular frequency of motion), according to Faraday's law of electromagnetic induction, the permanent magnet of the mover induces E in coils 1 to 4. m The alternating back electromotive force of cos(wt), where E m is the maximum back electromotive force value of the permanent magnetic field of the rotor induced in a single coil, then the back electromotive force value induced by the entire additional winding is 4E m cos(wt), that is, the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding add 4E m cos(wt).

[0053] When using a microcontroller such as a single chip microcomputer to collect the back electromotive force value of the additional winding, 4E should be met m cos(wt)≤V ADC Based on this, see Figure 4 and Figure 5 , Figure 4 is the induced electromotive force waveform of the additional winding at the same piston stroke and the same frequency under different main winding currents, Figure 5 For Figure 4 Fourier analysis of different waveforms. Under different main winding currents, the fundamental amplitude of the induced electromotive force of the additional winding is almost unchanged. Since the induced electromotive force of the additional winding is approximately equal to its output voltage, the corresponding relationship between the fundamental amplitude of the output voltage of the additional winding and the piston stroke signal of the linear oscillation motor can be used to obtain the corresponding piston stroke observation result, thereby realizing piston stroke control of the linear oscillation motor.

[0054] The present invention designs an additional winding on the stator outer teeth of the permanent magnet linear oscillation motor. When the working current is passed through the linear oscillation motor, the piston of the linear oscillation motor moves alternately under the action of the permanent magnetic field. The permanent magnetic field can induce an induced electromotive force with periodic frequency alternation in each coil of the additional winding, that is, the induced electromotive force in each coil of the additional winding forms a corresponding relationship with the motor piston. Therefore, the piston stroke signal of the linear oscillation motor can be obtained directly by using the fundamental amplitude of the output voltage of the additional winding to realize the observation of the piston stroke of the linear oscillation motor. The corresponding advantages are as follows: first, the stroke signal is independent of the parameters of the main winding (the original armature winding of the linear oscillation motor). Since the additional winding is designed on the stator outer teeth, it is less affected by heat; and, no additional current is passed through the designed additional winding, and it is not a heat source. When the working environment temperature is high, it has little effect on the piston stroke signal, which improves the robustness and accuracy of the piston stroke observation. Secondly, the motor piston stroke observation is performed based on the additional winding designed by the present invention, and no mechanical position sensor is required. This is a position sensor-free piston stroke observation of a linear oscillation motor, which retains the advantages of the linear oscillation motor in terms of small size and high integration. Thirdly, the piston stroke signal is directly obtained, rather than the existing method of first calculating the piston position based on the induced electromotive force of the main winding and then determining the piston stroke based on the piston position, which has the advantage of simple observation.

[0055] In general, simulation analysis and prototype experiments have proved that the linear oscillation motor piston stroke induction type additional winding design method proposed in the present invention is suitable for occasions where the main winding parameter variation range is large and the robustness is not strong, resulting in inaccurate piston stroke observation.

[0056] Example 2

[0057] The embodiment of the present invention provides a linear oscillation motor piston stroke induction type additional winding, and the additional winding is designed by the linear oscillation motor piston stroke induction type additional winding design method in the above-mentioned embodiment 1.

[0058] For the related technical solutions, please refer to the corresponding description in Example 1, which will not be repeated here.

[0059] Example 3

[0060] like Figure 6 As shown, an embodiment of the present invention provides a method for observing the piston stroke of a linear oscillation motor, wherein the linear oscillation motor is a permanent magnet linear oscillation motor with stator external teeth, and the method comprises:

[0061] Arranging an additional winding on the stator outer teeth of the linear oscillation motor, the additional winding is designed by the additional winding design method in the above-mentioned embodiment 1, or is the additional winding in embodiment 2;

[0062] When the working current is passed through the linear oscillation motor, the additional winding induces the following when the motor piston makes linear reciprocating motion: Figure 4 The induced electromotive force shown;

[0063] The output voltage of the additional winding is sampled by A / D through the microcontroller to obtain the corresponding fundamental amplitude V madd , the fundamental amplitude V madd is the maximum sampling value for A / D sampling of the output voltage; when the additional winding has no additional series resistance, the output voltage of the additional winding is approximately equal to the total permanent magnetic field induced electromotive force e in the additional winding add When the additional winding has an additional series resistor, the output voltage of the additional winding is equal to the total permanent magnetic field induced electromotive force e in the additional winding. add The sum of the voltage drops across the resistor in series.

[0064] Based on the fundamental amplitude V madd The piston stroke signal X of the linear oscillation motor peak The corresponding relationship between: X peak =αV madd , α is the back electromotive force coefficient, and the piston stroke signal X of the linear oscillation motor is obtained peak , in order to observe the piston stroke of the linear oscillation motor.

[0065] The linear oscillation motor piston stroke observation method of the present invention uses neither a mechanical position sensor nor a main winding signal to identify the piston stroke, and the method has strong parameter robustness and more accurate stroke position observation accuracy.

[0066] Example 4

[0067] like Figure 6 As shown, an embodiment of the present invention provides a linear oscillation motor piston stroke control method, comprising:

[0068] The piston stroke signal obtained in Example 3 is closed-loop controlled to realize position sensorless piston stroke control based on additional windings. The closed-loop control includes closed-loop control methods such as PI control or PID control.

[0069] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A design method for a linear oscillation motor piston stroke induction type additional winding, characterized in that: The linear oscillation motor is a permanent magnet linear oscillation motor with stator external teeth, comprising: An additional winding is arranged on the stator outer teeth of the linear oscillation motor, and when the linear oscillation motor is supplied with working current to make the motor piston perform linear reciprocating motion, a permanent magnetic field induced electromotive force is generated in each coil of the additional winding; Based on the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding add , calculate the number of turns N of each coil a , and obtain the designed additional winding; wherein the additional winding output voltage V add Fundamental amplitude V madd The piston stroke signal X of the linear oscillation motor peak Corresponding relationship: X peak =αV madd , α is the back electromotive force coefficient; N a The calculation formula is: Where m is the total number of coils in the additional winding. represents the permanent magnetic field induced electromotive force of each conductor in the coil, t represents time, V ADC is the maximum value of the microcontroller sampling voltage, and the microcontroller is used to output the additional winding voltage V add Perform A / D sampling to obtain the fundamental amplitude V madd .

2. The linear oscillation motor piston stroke induction type additional winding design method according to claim 1, characterized in that: The total number of coils of the additional winding is an even number and is symmetrically distributed on the stator outer teeth of the linear oscillation motor.

3. The linear oscillation motor piston stroke induction type additional winding design method according to claim 1, characterized in that: The total number of stator external teeth of the linear oscillation motor is an even number, one coil is arranged on each stator external tooth, and each coil constitutes the additional winding.

4. The method for designing a piston stroke induction type additional winding of a linear oscillation motor according to any one of claims 1 to 3, characterized in that: The coils of the additional winding are connected in series or in series-parallel to form a superimposed permanent magnetic field induced electromotive force.

5. The linear oscillation motor piston stroke induction type additional winding design method according to claim 4, characterized in that: The coils of the additional winding are connected in series through the same-name ends to form the superimposed permanent magnetic field induced electromotive force.

6. The linear oscillation motor piston stroke induction type additional winding design method according to claim 1, characterized in that: When the microcontroller samples the maximum voltage V ADC When the voltage exceeds a preset threshold, the linear oscillation motor piston stroke induction type additional winding design method further includes: A resistor is connected in series with the additional winding. At this time, the output voltage V add is the total permanent magnetic field induced electromotive force e generated by the superposition of the coils of the additional winding add The sum of the voltage drops caused by the resistance in series with the additional winding.

7. The linear oscillation motor piston stroke induction type additional winding design method according to claim 1, characterized in that: The permanent magnet linear oscillation motor with stator external teeth is a C-type or E-type moving magnet or moving iron linear oscillation motor.

8. An additional winding designed by the method for designing a piston stroke induction type additional winding of a linear oscillation motor as described in any one of claims 1 to 7.

9. A method for observing the piston stroke of a linear oscillation motor, characterized in that: include: An additional winding is arranged on the outer teeth of the stator of the linear oscillation motor; wherein the additional winding is designed by the design method of the piston stroke induction type additional winding of the linear oscillation motor according to any one of claims 1 to 7, or is the additional winding according to claim 8; When the linear oscillation motor is supplied with working current to make the motor piston perform linear reciprocating motion, a permanent magnetic field induced electromotive force is generated in each coil of the additional winding, and a microcontroller is used to output a voltage V add Perform A / D sampling to obtain the fundamental amplitude V madd ; Based on the fundamental amplitude V madd The piston stroke signal X of the linear oscillation motor peak The corresponding relationship between: X peak =αV madd , get the piston stroke signal X of the linear oscillation motor peak , so as to observe the piston stroke of the linear oscillation motor.

10. A method for controlling piston stroke of a linear oscillating motor without position sensor based on an additional winding, characterized in that: include: The linear oscillation motor piston stroke observation method described in claim 9 is used to obtain the piston stroke signal of the linear oscillation motor; the piston stroke signal is closed-loop controlled to realize position sensorless piston stroke control of the linear oscillation motor based on the additional winding.

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