Detection control method and detection device for top dead center of piston of linear compressor

Abstract

The invention relates to the technical field of mechanical automation control, and provides a linear compressor piston top dead center detection method and device, and the method comprises the steps: calibrating the corresponding relation between the output voltage of a Hall coil and the distance between a piston and a top dead center; high-frequency sine alternating-current voltage is applied to the Hall coil, when the distance between the Hall coil and the rotor conductor is changed, the oscillation frequency of an LC oscillation circuit formed by the Hall coil is changed, and the real-time output voltage of the Hall coil is read by a frequency signal through a frequency-voltage conversion and detection circuit; the real-time output voltage of the Hall coil is compared with the corresponding relation between the output voltage of the Hall coil and the distance between the piston and the top dead center, and the linear compressor is controlled to operate at the top dead center; according to load feedback, by adjusting output electrical parameters of a linear compressor driving circuit and keeping the real-time output voltage of a Hall coil smaller than the corresponding voltage of a piston top dead center calibrated in a control chip, variable capacity adjustment is carried out, the load side is stabilized at a set target, and it is guaranteed that cylinder collision does not occur during operation of the compressor.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical automation control, and in particular to a linear compressor piston top dead point detection control method and a detection device. Background Art

[0002] The linear compressor retains the advantage of high volumetric efficiency of the piston compressor, while eliminating the mechanical transmission mechanism. It has high mechanical efficiency, simple structure, and strong reliability, and can be widely used in low temperature, refrigeration and heat pump systems. Since the linear compressor adopts a free piston structure, the piston displacement is easily affected by external working conditions. When the compressor is under different suction and exhaust pressures, the piston offset changes, resulting in a change in the stroke required for the piston to reach the top dead center position. The displacement of the piston motion center position is more obvious in large pressure difference and high pressure ratio systems. Through the circuit balance equation And the kinetic equilibrium equation Solving the piston stroke and then performing top dead point position detection and control will cause inaccurate top dead point control due to the offset of the motion center. At the same time, the nonlinearity of the characteristic parameters of the linear motor will also cause errors in the piston stroke calculation, which brings huge challenges to the judgment and control of the top dead point of the compressor. Cylinder collision is prone to occur, especially under the condition of sudden changes in the suction and exhaust pressure of the compressor.

[0003] In the prior art, the position of the top dead point is determined by the inflection point of the phase difference between the current and the piston displacement. The interference caused by the change in working conditions also leads to the phenomenon of cylinder collision due to inaccurate detection of the top dead point of the compressor. The traditional method of using displacement sensors to detect the piston stroke of linear compressors generally has the problems of high cost, complex installation, and poor adaptability to harsh working environments (such as high temperature, high vibration, and strong electromagnetic interference). In addition, the sensor is large in size and it is difficult to meet the needs of the linear compressor to develop in the direction of miniaturization and integration, thus limiting its wide application. Summary of the invention

[0004] The present invention provides a linear compressor top dead point detection control method and detection device, which are used to solve the defects of inaccurate top dead point control of linear compressors and easy cylinder collision in the prior art, thereby improving the accuracy of top dead point detection of linear compressors, reducing the manufacturing cost of linear compressors, and promoting the application of linear compressors in low temperature, refrigeration, and heat pump systems.

[0005] The present invention provides a linear compressor top dead point detection control method, comprising: Calibrate the corresponding relationship between the output voltage of the Hall coil and the distance from the piston to the top dead center; A high-frequency sinusoidal AC voltage is applied to the Hall coil. When the distance between the Hall coil and the mover conductor changes, the oscillation frequency of the LC oscillation circuit formed by the Hall coil changes, and the frequency signal is converted into a frequency voltage and the detection circuit reads the real-time output voltage of the Hall coil; Comparing the real-time output voltage of the Hall coil with the corresponding relationship between the output voltage of the Hall coil and the distance from the piston to the top dead center, and controlling the linear compressor to operate at the top dead center; According to load feedback, by adjusting the output electrical parameters of the linear compressor drive circuit, the real-time output voltage of the Hall coil is kept lower than the corresponding voltage of the piston top dead center calibrated in the control chip, and variable capacity adjustment is performed to achieve the load side stabilization at the set target, ensuring that the compressor does not collide with the cylinder during operation.

[0006] According to a linear compressor top dead point detection control method provided by the present invention, the calibration of the corresponding relationship between the output voltage of the Hall coil and the distance from the piston to the top dead point includes: Install the Hall coil to the linear compressor and start the compressor to run at no load; When a high-frequency sinusoidal AC voltage is applied to the Hall coil, the oscillation frequency of the LC oscillator formed by the Hall coil changes; The output voltage of the Hall coil is measured by the conversion measurement circuit, and the distance between the piston end and the top dead center is measured by the displacement sensor; The corresponding relationship between the output voltage of the Hall coil and the distance between the piston and the top dead center when the linear compressor does not compress gas is obtained.

[0007] According to a linear compressor top dead point detection control method provided by the present invention, in applying a high-frequency sinusoidal AC voltage to the Hall coil, the high-frequency sinusoidal AC voltage is applied using low-voltage AC power.

[0008] According to a linear compressor top dead point detection control method provided by the present invention, the real-time output voltage of the Hall coil is compared with the corresponding relationship between the output voltage of the Hall coil and the distance between the piston and the top dead point, and the linear compressor is controlled to operate at the top dead point, including: The output voltage and frequency of the compressor drive circuit are adjusted through the PID control algorithm to control the linear compressor to run at the top dead center.

[0009] According to a linear compressor top dead point detection control method provided by the present invention, according to load feedback, by adjusting the output electrical parameters of the linear compressor drive circuit, keeping the real-time output voltage of the Hall coil less than the corresponding voltage of the piston top dead point calibrated in the control chip, performing variable capacity adjustment, achieving the load side stable at the set target, and ensuring that the compressor does not collide with the cylinder during operation, including: According to the temperature feedback, the output voltage and frequency of the linear compressor drive circuit are adjusted.

[0010] The present invention also provides a linear compressor top dead point detection device, comprising: A Hall coil, a controller and a conductor metal, wherein the Hall coil is arranged on the inner stator of a linear compressor; the conductor metal is located in the alternating magnetic field generated by the Hall coil; the controller comprises an LC oscillation circuit, a transformation measurement circuit and a compressor drive circuit connected in sequence, and the Hall coil constitutes an inductance element of the LC oscillation circuit; the controller also comprises a control circuit, and the transformation measurement circuit and the compressor drive circuit are both connected to the control circuit.

[0011] According to a linear compressor top dead point detection device provided by the present invention, the Hall coil is arranged on the stator of the linear compressor on the side close to the exhaust valve, and the conductor metal is arranged on the piston corresponding to the Hall coil on the side close to the exhaust valve.

[0012] According to a linear compressor top dead point detection device provided by the present invention, the Hall coil is arranged on the stator of the linear compressor away from the exhaust valve, and the conductor metal is arranged on the piston corresponding to the Hall coil away from the exhaust valve.

[0013] According to a linear compressor top dead point detection device provided by the present invention, the Hall coil comprises a hollow cylinder wound with a metal wire, and the metal wire is wound at least twice along the axial direction of the hollow cylinder.

[0014] According to a linear compressor top dead point detection device provided by the present invention, the Hall coil includes a hollow cylinder wound with a metal wire, a cylindrical magnetic conductive core is axially arranged inside the hollow cylinder, and the metal wire is wound at least twice along the axial direction of the cylindrical magnetic conductive core.

[0015] The linear compressor top dead point detection control method and detection device provided by the present invention realize accurate detection and control of the top dead point of the linear compressor piston by embedding the Hall coil in the linear compressor and utilizing the electromagnetic coupling between the sinusoidal alternating magnetic field generated by the Hall coil and the eddy current magnetic field generated on the metal conductor of the mover, thereby eliminating the interference of the piston offset on the top dead point detection, preventing the linear compressor from hitting the cylinder, improving the working reliability and the operating efficiency of the compressor, and ensuring the stable and efficient operation of the linear compressor; At the same time, the present invention converts the piston position of the linear compressor into the frequency change of the LC circuit composed of the Hall coil and finally converts it into a voltage signal, thereby eliminating the sensor component. The Hall coil is small in size and low in power consumption. The conversion and measurement circuit is integrated into the compressor controller, which simplifies the structure of the linear compressor and is conducive to the miniaturization and integration of the linear compressor. While reducing the manufacturing difficulty and cost of the linear compressor, the overall reliability is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a flow chart of the top dead point detection control method of a linear compressor provided by the present invention.

[0018] Figure 2 It is an operation mode diagram of the linear compressor top dead point detection control method provided by the present invention.

[0019] Figure 3 This is an offline calibration flow chart provided by the present invention.

[0020] Figure 4 It is a structural schematic diagram of the off-line calibration system provided by the present invention.

[0021] Figure 5 It is a curve schematic diagram of the off-line calibration system provided by the present invention.

[0022] Figure 6 It is a simplified schematic diagram of the electromagnetic field of the Hall coil and the piston provided by the present invention.

[0023] Figure 7 It is an equivalent circuit diagram of the Hall coil and the piston provided by the present invention.

[0024] Figure 8 It is a general structural diagram of an embodiment of the present invention on a Medis type linear motor.

[0025] Fig. 9 It is a general structural diagram of an embodiment of the present invention on a Redlich type linear motor.

[0026] Fig.10 It is a schematic diagram of the installation structure of the Hall coil provided in an embodiment of the present invention.

[0027] Fig.11 4 is a measurement circuit diagram of an embodiment of the present invention.

[0028] Fig.12 Schematic diagram of a linear compressor refrigeration system according to an embodiment of the present invention.

[0029] Reference numerals: 1. Hall coil; 2. Controller; 21. LC oscillation circuit; 22. Conversion measurement circuit; 23. Compressor drive circuit; 24. Control circuit; 3. Internal stator; 4. Conductor metal; 5. Cylinder; 6. Terminal block; 7. Horizontal pan; 8. Laser displacement sensor; 9. Display; 10. Mover; 100. Compressor; 200. Evaporator; 300. Temperature sensor; 400. Condenser; 500. Throttle valve. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0032] Combine the following Figure 1-Figure 6 The top dead point detection control method of a linear compressor of the present invention is described.

[0033] Figure 1 FIG. 1 is one of the flow charts of the linear compressor top dead point detection control method provided by the present invention, such as Figure 1 and Figure 2 As shown, the method includes the following: Step S1, calibrating the corresponding relationship between the output voltage of the Hall coil and the distance from the piston to the top dead center.

[0034] In step S1, there is a certain relationship between the output voltage of the Hall coil and the position of the piston from the top dead center. In order to accurately detect the piston position, this relationship must first be calibrated. The calibration process may involve measuring the output voltage of the Hall coil at different piston positions and recording these data.

[0035] Step S2, applying a high-frequency sinusoidal AC voltage to the Hall coil. When the distance between the Hall coil and the mover conductor changes, the oscillation frequency of the LC oscillation circuit formed by the Hall coil changes, and the frequency signal is converted through the frequency voltage and the detection circuit reads the real-time output voltage of the Hall coil.

[0036] In step S2, according to Ferrari's law of electromagnetic induction, a high-frequency sinusoidal alternating current is passed through the Hall coil, generating a sinusoidal alternating magnetic field around the coil, causing the conductor piston located in the alternating magnetic field to generate an induced current, which in turn generates a new alternating magnetic field that hinders the change of the original magnetic field.

[0037] The oscillation frequency change of the LC oscillation circuit will be converted into a frequency signal. The real-time output voltage of the Hall coil can be read through the frequency voltage conversion and detection circuit. The real-time output voltage reflects the current position information of the piston.

[0038] Step S3, comparing the real-time output voltage of the Hall coil with the corresponding relationship between the output voltage of the Hall coil and the distance between the piston and the top dead center, and controlling the linear compressor to run at the top dead center.

[0039] In step S3, the real-time read output voltage of the Hall coil is compared with the previously calibrated correspondence between the output voltage of the Hall coil and the distance from the piston to the top dead center, and the comparison result can be used to determine whether the piston is close to the top dead center. According to the comparison result, if the piston is close to the top dead center, the linear compressor is controlled to run with appropriate parameters to ensure that it works stably near the top dead center.

[0040] Step S4, according to load feedback, by adjusting the output electrical parameters of the linear compressor drive circuit, keep the real-time output voltage of the Hall coil smaller than the corresponding voltage of the piston top dead center calibrated in the control chip, perform variable capacity adjustment, achieve load side stability at the set target, and ensure that the compressor does not collide with the cylinder during operation.

[0041] In step S4, the compressor will continuously receive load feedback signals during operation. Based on these load feedback signals, the compressor capacity can be adjusted by adjusting the output electrical parameters of the compressor drive circuit. The purpose of the adjustment is to keep the real-time output voltage of the Hall coil lower than the corresponding voltage of the piston top dead center calibrated in the control chip, so as to avoid failures such as cylinder collision in the compressor.

[0042] like Figure 3 As shown, in a feasible embodiment of the present invention, in step S1, calibrating the corresponding relationship between the output voltage of the Hall coil and the distance from the piston to the top dead center specifically includes: S11. Install the Hall coil to the linear compressor and start the compressor to run at no load.

[0043] In step S11, the linear compressor does not compress the gas, but just runs.

[0044] S12. After a high-frequency sinusoidal AC voltage is applied to the Hall coil, the oscillation frequency of the LC oscillator formed by the Hall coil changes.

[0045] S13, measuring the output voltage of the Hall coil by transforming the measuring circuit, and measuring the distance between the piston end and the top dead center by the displacement sensor.

[0046] S14, obtaining the corresponding relationship between the output voltage of the Hall coil and the distance between the piston and the top dead center when the linear compressor does not compress gas.

[0047] like Figure 4 As shown in FIG. 1 , the offline calibration system includes a horizontal pan-tilt table 7, a laser displacement sensor 8 and a display 9. The laser displacement sensor 8 is arranged on the horizontal pan-tilt table 7. The display 9 is connected to the laser displacement sensor 8. During the offline calibration process, the horizontal pan-tilt table 7 is adjusted to keep the laser displacement sensor 8 perpendicular to the end surface of the piston metal 4. The linear compressor is started, and the voltage is gradually increased to make the compressor run to the top dead point. The voltage value read by the measuring circuit at this moment is recorded. The result is as follows: Figure 5 shown.

[0048] Specifically, in the above step S2, the high-frequency sinusoidal alternating current voltage adopts low-voltage alternating current.

[0049] In the above step S3, the output voltage and frequency of the compressor driving circuit are adjusted by a PID control algorithm to control the linear compressor to operate at the top dead center.

[0050] In the above step S4, the output voltage and frequency of the linear compressor driving circuit are adjusted according to the temperature feedback.

[0051] like Figure 6 and Figure 7 The figure shows a simplified schematic diagram of the electromagnetic field of the Hall coil and the piston and an equivalent circuit diagram of the embodiment of the present invention. According to Ferrari's electromagnetic induction law, a high-frequency sinusoidal alternating current is passed through the Hall coil, and a sinusoidal alternating magnetic field is generated around the coil, so that the conductor piston located in the alternating magnetic field generates an induced current, and the induced current generates a new alternating magnetic field that hinders the change of the original magnetic field. Through the electromagnetic coupling between the Hall coil and the highly conductive piston, the equivalent impedance of the Hall coil changes.

[0052] Therefore, the top dead point detection control method for a linear compressor provided by the present invention can realize accurate detection of the top dead point position when the piston offset occurs under a large pressure difference in the linear compressor, thereby eliminating the interference of the piston offset on the top dead point detection, preventing the piston from hitting the cylinder, and improving the adaptability and reliability of the top dead point control of the linear compressor; moreover, by converting the piston position of the linear compressor into the frequency change of the LC circuit composed of the Hall coil and finally converting it into a voltage signal, the sensor component is eliminated, the composition structure of the linear compressor is simplified, the manufacturing difficulty and cost of the linear compressor are reduced, and the overall reliability is improved.

[0053] The linear compressor top dead point detection device provided by the present invention is described below. The linear compressor top dead point detection device described below and the linear compressor top dead point detection control method described above can be referenced to each other.

[0054] like Figure 8-Figure 11 As shown, the second aspect of the embodiment of the present invention is to provide a linear compressor top dead point detection device, including a Hall coil 1, a controller 2 and a conductor metal 4, the Hall coil 1 is arranged on the inner stator 3 of the linear compressor; the conductor metal 4 is arranged in the alternating magnetic field generated by the Hall coil 1; the controller 2 includes an LC oscillation circuit 21, a transformation measurement circuit 22 and a compressor drive circuit 23 connected in sequence, and the Hall coil 1 constitutes an inductance element of the LC oscillation circuit 21; the controller 2 also includes a control circuit 24, and the transformation measurement circuit 22 and the compressor drive circuit 23 are both connected to the control circuit 24.

[0055] The detection device provided by the present invention realizes accurate detection and control of the top dead point of the piston of the linear compressor by building a Hall coil into the linear compressor and utilizing the electromagnetic coupling between the sinusoidal alternating magnetic field generated by the coil and the eddy current magnetic field generated on the metal conductor of the mover, thereby preventing the linear compressor from hitting the cylinder, improving the working reliability and the operating efficiency of the compressor, and ensuring the stable and efficient operation of the linear compressor.

[0056] like Figure 8 As shown, in a feasible embodiment of the present invention, the Hall coil 1 is arranged on the stator of the linear compressor on the side close to the exhaust valve, and the conductor metal 4 is arranged on the piston corresponding to the Hall coil on the side close to the exhaust valve.

[0057] like Fig. 9 As shown, in a feasible embodiment of the present invention, the Hall coil 1 is arranged on the stator of the linear compressor away from the exhaust valve, and the conductor metal 4 is arranged on the piston corresponding to the Hall coil away from the exhaust valve.

[0058] like Fig.10As shown, that is, the Hall coil 1 is attached to the end surface of the inner stator 3 close to the conductor metal 4, and the power-carrying wire is connected to the terminal 6 through the holes punched on the inner stator 3 and the cylinder 5, and then connected to the controller 2.

[0059] According to Ferrari's law of electromagnetic induction, a high-frequency sinusoidal alternating current is passed through the Hall coil 1, and a sinusoidal alternating magnetic field is generated around it, so that the conductor metal 4 located in the alternating magnetic field generates an induced current, and the induced current generates a new alternating magnetic field that hinders the change of the original magnetic field. Through the electromagnetic coupling between the Hall coil 1 and the conductor metal 4, the equivalent impedance and equivalent inductive reactance of the Hall coil 1 change. The conductor metal 4 reciprocates in the cylinder 5, and the distance between the conductor metal 4 and the Hall coil 1 changes, and the change in the equivalent impedance and equivalent inductive reactance of the Hall coil 1 changes. When the piston reaches the top dead center position, the change reaches the maximum value.

[0060] like Fig.11 As shown, the Hall coil 1 serves as the inductance element of the LC oscillation circuit 21. The equivalent inductance of the Hall coil 1 causes the oscillation frequency of the LC oscillation circuit 21 to change due to the influence of eddy current. The corresponding voltage is read out by the transformation measurement circuit 22, and the piston stroke of the linear compressor is detected by comparing the voltage with the calibration value.

[0061] In a feasible embodiment of the present invention, the Hall coil 1 comprises a hollow cylinder wound with a metal wire, and the metal wire is wound at least twice along the axial direction of the hollow cylinder.

[0062] In a feasible embodiment of the present invention, the Hall coil 1 comprises a hollow cylinder wound with a metal wire, a cylindrical magnetic conductive core is axially arranged inside the hollow cylinder, and the metal wire is wound at least twice along the axial direction of the cylindrical magnetic conductive core.

[0063] like Fig.12 As shown, a linear compressor refrigeration system is provided, which adds temperature feedback control on the basis of the basic refrigeration cycle. When the target temperature is determined, the compressor first runs at full stroke, and then starts variable capacity operation when the temperature reaches the target temperature or the cooling capacity is not high.

[0064] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or modes described in this specification and the features of the different embodiments or modes, without contradiction.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A linear compressor top dead point detection control method, characterized in that: include: Calibrate the corresponding relationship between the output voltage of the Hall coil and the distance from the piston to the top dead center; A high-frequency sinusoidal AC voltage is applied to the Hall coil. When the distance between the Hall coil and the mover conductor changes, the oscillation frequency of the LC oscillation circuit formed by the Hall coil changes, and the frequency signal is converted into a frequency voltage and the detection circuit reads the real-time output voltage of the Hall coil; Comparing the real-time output voltage of the Hall coil with the corresponding relationship between the output voltage of the Hall coil and the distance from the piston to the top dead center, and controlling the linear compressor to operate at the top dead center; According to load feedback, by adjusting the output electrical parameters of the linear compressor drive circuit, the real-time output voltage of the Hall coil is kept lower than the corresponding voltage of the piston top dead center calibrated in the control chip, and variable capacity adjustment is performed to achieve the load side stabilization at the set target, ensuring that the compressor does not collide with the cylinder during operation.

2. The linear compressor top dead point detection control method according to claim 1, characterized in that: The calibration of the correspondence between the output voltage of the Hall coil and the distance between the piston and the top dead center includes: Install the Hall coil to the linear compressor and start the compressor to run at no load; When a high-frequency sinusoidal AC voltage is applied to the Hall coil, the oscillation frequency of the LC oscillator formed by the Hall coil changes; The output voltage of the Hall coil is measured by the conversion measurement circuit, and the distance between the piston end and the top dead center is measured by the displacement sensor; The corresponding relationship between the output voltage of the Hall coil and the distance between the piston and the top dead center when the linear compressor does not compress gas is obtained.

3. The linear compressor top dead point detection control method according to claim 1, characterized in that: In the step of applying a high-frequency sinusoidal alternating current voltage to the Hall coil, low-voltage alternating current is used for applying the high-frequency sinusoidal alternating current voltage.

4. The linear compressor top dead point detection control method according to claim 1, characterized in that: The method of comparing the real-time output voltage of the Hall coil and the corresponding relationship between the output voltage of the Hall coil and the distance between the piston and the top dead center, and controlling the linear compressor to operate at the top dead center, includes: The output voltage and frequency of the compressor drive circuit are adjusted through the PID control algorithm to control the linear compressor to run at the top dead center.

5. The linear compressor top dead point detection control method according to claim 1, characterized in that: According to the load feedback, by adjusting the output electrical parameters of the linear compressor drive circuit, the real-time output voltage of the Hall coil is kept smaller than the corresponding voltage of the piston top dead center calibrated in the control chip, and variable capacity adjustment is performed to achieve the load side stabilization at the set target, ensuring that the compressor does not collide with the cylinder during operation, including: According to the temperature feedback, the output voltage and frequency of the linear compressor drive circuit are adjusted.

6. A detection device using the linear compressor top dead point detection control method according to any one of claims 1 to 5, characterized in that: include: A Hall coil (1), a controller (2) and a conductor metal (4), wherein the Hall coil (1) is arranged on an inner stator (3) of a linear compressor; the conductor metal (4) is located in an alternating magnetic field generated by the Hall coil (1); the controller (2) comprises an LC oscillation circuit (21), a conversion measurement circuit (22) and a compressor drive circuit (23) which are connected in sequence, and the Hall coil (1) constitutes an inductance element of the LC oscillation circuit (21); the controller (2) also comprises a control circuit (24), and the conversion measurement circuit (22) and the compressor drive circuit (23) are both connected to the control circuit (24).

7. The linear compressor top dead point detection device according to claim 6, characterized in that: The Hall coil (1) is arranged on a stator on a side of the linear compressor close to an exhaust valve, and the conductor metal (4) is arranged on a piston corresponding to the Hall coil on a side close to the exhaust valve.

8. The linear compressor top dead point detection device according to claim 6, characterized in that: The Hall coil (1) is arranged on the stator of the linear compressor on a side away from the exhaust valve, and the conductor metal (4) is arranged on the piston corresponding to the side of the Hall coil away from the exhaust valve.

9. The linear compressor top dead point detection device according to claim 6, characterized in that: The Hall coil (1) comprises a hollow cylinder wound with a metal wire, and the metal wire is wound at least twice along the axial direction of the hollow cylinder.

10. The linear compressor top dead point detection device according to claim 6, characterized in that: The Hall coil (1) comprises a hollow cylinder wound with a metal wire, a cylindrical magnetic conductive core is axially arranged inside the hollow cylinder, and the metal wire is wound at least twice along the axial direction of the cylindrical magnetic conductive core.

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