Power supply circuit of state detection sensor

Abstract

The invention relates to the field of electricity, in particular to a power supply circuit of a state detection sensor. Comprising a magnetic flux ring which comprises a magnetic ring and an induction coil wound on the magnetic ring, is installed on a motor detected by a state detection sensor, and is used for generating electric energy by using magnetic leakage generated when the motor works; the input end of the rectifying and voltage stabilizing circuit is connected to the induction coil of the magnetic flux ring, the output end of the rectifying and voltage stabilizing circuit is connected to the charging end of an energy storage device, and the rectifying and voltage stabilizing circuit is used for converting electric energy generated by the magnetic flux ring into direct current and storing the direct current in the energy storage device; the output end of the energy storage device is connected to the state detection sensor for supplying power to the state detection sensor. By adopting the power supply circuit of the state detection sensor, power can be stably and continuously supplied to the state detection sensor, and the working stability and reliability of the state detection sensor are guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of electricity. More specifically, the present invention relates to a power supply circuit for a state detection sensor. Background Art

[0002] An AC motor is a device that converts electrical energy of alternating current into mechanical energy. It mainly consists of a stator winding and a rotor. The AC motor utilizes the principle of electromagnetic induction to convert the input alternating current electrical energy into mechanical energy output through the electromagnetic interaction between the stator and the rotor. The main components of the AC motor include the stator, rotor, air gap, end cover, etc. Among them, the stator is fixed and used to generate a rotating magnetic field; the rotor can rotate within the stator and is used to output mechanical energy. The AC motor has a high energy conversion efficiency and can convert most of the input electrical energy into mechanical energy output.

[0003] AC motors are widely used in the industrial field (such as machine tools, conveyor belts, cranes, compressors and other mechanical equipment). The real-time monitoring of their operating status is crucial for ensuring production safety and improving equipment reliability. State detection sensors can obtain various operating parameters of the motor, such as temperature, vibration, current, etc., providing key data for predictive maintenance. However, the power supply problem of the sensors has always been an important factor restricting their wide application. There are usually two ways to power the state detection sensor. One is to use a power generation device to power it, and the other is to use an energy storage device to power it. There are usually three types of power generation devices that can power the state detection sensor, namely a solar power generation device, a vibration power generation module, and a generator. For the solar power generation device, since most AC motors are installed inside the factory building, the solar power generation device cannot obtain sunlight for power generation. For the vibration power generation module, it requires a relatively large displacement to generate electricity, and only special equipment such as vibrating screens has a large displacement for power generation, but most industrial applications of AC motors cannot meet this requirement. When using a generator to power the state detection sensor, the AC motor needs to drive the generator to generate electricity. Although this method is available, it has many drawbacks: (1) It changes the original structure of the AC motor, which is not only cumbersome in retrofit construction, but also not guaranteed by the AC motor manufacturer. (2) The added generator will increase the load of the AC motor. (3) The added generator has rolling bearings that need to be regularly maintained and replaced, increasing the maintenance cost and the number of failure points, posing a safety risk.

[0004] When using an energy storage device to power a state detection sensor, an energy storage battery is usually adopted. However, the battery power is limited. When the battery power is too low, it will cause unstable power supply to the state detection sensor, which in turn leads to poor working reliability and stability of the state detection sensor. When the battery power is too low, the battery needs to be replaced or charged. However, this not only increases the maintenance cost, but also in some special environments (such as high temperature, high humidity, high dust, etc.), the battery replacement operation is difficult and there are safety risks. Summary of the Invention

[0005] To solve the technical problem that the power supply method of the state detection sensor in the prior art will lead to poor working reliability and stability of the detection sensor, the present invention provides solutions in the following aspects.

[0006] In a first aspect, the present invention provides a power supply circuit for a state detection sensor, including: a magnetic flux ring, including a magnetic ring and an induction coil wound around the magnetic ring, installed on the motor detected by the state detection sensor, and used to generate electric energy by using the leakage magnetic flux generated when the motor works; a rectifying and voltage stabilizing circuit, whose input end is connected to the induction coil of the magnetic flux ring, and the output end is connected to the charging end of the energy storage device, and is used to convert the electric energy generated by the magnetic flux ring into direct current and store it in the energy storage device; the output end of the energy storage device is connected to the state detection sensor to supply power to it.

[0007] The beneficial effects are as follows: The power supply circuit of the state detection sensor in this embodiment, by setting a magnetic flux ring on the motor, when the motor rotates, the leakage magnetic flux generated by it will pass through the ring surface of the magnetic flux ring. Since the leakage magnetic flux generated by the motor is a rotating magnetic field, the magnetic flux passing through the ring surface of the magnetic flux ring will change during the rotation of the leakage magnetic flux, thereby generating an induced electromotive force (that is, generating electric energy) in the magnetic flux ring, generating electric energy by using the leakage magnetic flux, thus improving the economy of the sensor power supply circuit; by setting a rectifying and voltage stabilizing circuit and an energy storage device, the generated electric energy is rectified, stored and supplied to the state detection sensor in real time. The power supply circuit of the state detection sensor in this embodiment can use the leakage magnetic flux generated when the motor rotates to generate electric energy in real time and supply power to the state detection sensor, so as to achieve stable and continuous power supply to the state detection sensor and ensure the stability and reliability of the state detection sensor during operation; in addition, by setting an energy storage device to store the generated electric energy, the waste of electric energy is avoided; the power supply circuit of the state detection sensor in this embodiment does not adopt maintenance-consuming parts and does not need to be maintained.

[0008] Preferably, the magnetic flux ring is installed on the axis or side of the motor and is located on the outer surface of the motor.

[0009] Its beneficial effects are as follows: By installing the magnetic flux ring on the axis or side of the motor, the magnetic flux ring can efficiently collect the leakage magnetic flux of the motor; by installing the magnetic flux ring on the outer surface of the motor, that is, non-intrusive installation, the original structure of the motor can be avoided from being changed.

[0010] Preferably, the rectifying and voltage-stabilizing circuit uses an energy harvesting boost charging IC with the model number BQ25504.

[0011] Preferably, the design method of the magnetic flux ring includes: Determine the number of turns of the coil of the magnetic flux ring and the power generation power of the magnetic flux ring; According to the number of turns of the coil, the power generation power, combined with the rotational speed and the number of pole pairs of the motor, calculate the diameter of the magnetic flux ring, and its calculation expression is: ; In the formula, D represents the diameter of the magnetic flux ring, P represents the power generation power of the magnetic flux ring, R represents the load resistance of the magnetic flux ring, n represents the rotational speed of the motor, p represents the number of pole pairs of the motor, k 1 and k 2 are constants.

[0012] Its beneficial effects are as follows: In the design method of the magnetic flux ring of this embodiment, when determining the diameter of the magnetic flux ring, first determine the number of turns of the coil of the magnetic flux ring and the expected power generation power of the magnetic flux ring, and then determine the diameter of the magnetic flux ring according to the number of turns of the coil of the magnetic flux ring and the expected power generation power of the magnetic flux ring. When determining the diameter of the magnetic flux ring, the relationship between the diameter of the magnetic flux ring, the number of turns of the coil, the expected power generation power, the load resistance of the magnetic flux ring, the rotational speed and the number of pole pairs of the motor is comprehensively considered, so as to ensure that the power generation power of the designed magnetic flux ring meets the expected requirements, thereby providing reliable power supply for the state detection sensor.

[0013] Preferably, the value range of k 1 is 0.00003 - 0.0001, and the value range of k 2 is 1.5 - 2.5.

[0014] Preferably, determining the number of turns of the coil of the magnetic flux ring includes: Set the induced electromotive force , coil current , magnetic circuit reluctance , winding resistance and winding leakage inductance ; According to the induced electromotive force, coil current, magnetic circuit reluctance and winding leakage inductance of the magnetic flux ring, combined with the power supply frequency f of the motor, calculate the number of turns of the coil of the magnetic flux ring , and the calculation expression is: ; Wherein, k is a correction coefficient considering the core nonlinearity of the magnetic flux ring, and its value range is 0.00003 - 0.0001.

[0015] Its beneficial effects are as follows: When designing the number of turns of the coil of the magnetic flux ring in this embodiment, it is considered that the coil permeability is not a constant and will change with the change of the magnetic field strength. Especially at high magnetic field strengths, saturation will occur, resulting in a change in the magnetic reluctance of the magnetic circuit. The correction coefficient k is introduced to correct the calculation formula of the induced electromotive force; and the influence of the winding resistance and winding leakage inductance of the magnetic flux ring on the electromotive force output by the magnetic flux ring is considered, so as to ensure that the induced electromotive force generated by the designed magnetic flux ring during operation meets the expected requirements of the induced electromotive force and the expected power generation requirements, thereby providing reliable power supply for the state detection sensor.

[0016] Preferably, the induced electromotive force has a value range of 0.13 - 3V.

[0017] Preferably, the coil current has a value range of 0.01 - 0.5A. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By referring to the accompanying drawings and reading the following detailed description, the above and other objects, features, and advantages of the exemplary embodiments of the present invention will become readily understood. In the drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 is a schematic diagram showing the power supply circuit structure of the state detection sensor according to an embodiment of the present invention; Figure 2 is a schematic circuit diagram showing the circuit principle according to an embodiment of the present invention; Figure 3 is a schematic diagram showing the installation position of the magnetic flux ring according to an embodiment of the present invention; Figure 4 is a schematic flowchart showing the design method of the magnetic flux ring according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0020] The following will describe the specific embodiments of the present invention in detail with reference to the accompanying drawings.

[0021] Embodiment of the power supply circuit for the state detection sensor: As Figure 1 shown, the power supply circuit for the state detection sensor of the present invention includes: A magnetic flux ring, including a magnetic ring and an induction coil wound around the magnetic ring, is installed on the motor detected by the state detection sensor, and is used to generate electric energy by using the leakage magnetic flux generated during the operation of the motor; a rectification and voltage stabilization circuit, whose input end is connected to the induction coil of the magnetic flux ring, and the output end is connected to the charging end of the energy storage device, and is used to convert the electric energy generated by the magnetic flux ring into direct current and store it in the energy storage device; the output end of the energy storage device is connected to the state detection sensor to supply power to it.

[0022] In this embodiment, both ends of the induction coil of the magnetic flux ring are connected to the input end of the rectification and voltage stabilization circuit. The rectification and voltage stabilization circuit includes a rectification circuit, and the output of the rectification circuit is connected to the voltage stabilization circuit. Among them, the rectification circuit can adopt a half-wave rectification circuit, a full-wave rectification circuit or a bridge rectification circuit. The voltage stabilization circuit can adopt a shunt voltage stabilization circuit, a series voltage stabilization circuit or a switching voltage stabilization circuit.

[0023] The working principle of the power supply circuit for the state detection sensor of the present invention is as follows: When the motor operates, an alternating magnetic field is generated inside it, and part of the magnetic field will leak into the surrounding space (i.e., leakage magnetic flux). The magnetic flux ring collects this leakage magnetic flux, causing the magnetic flux passing through the induction coil to change. According to the electromagnetic induction law, an induced electromotive force will be generated in the induction coil, and its magnitude is proportional to the magnetic flux change rate. The frequency of the induced electromotive force is the same as the power supply frequency of the AC motor (for example, for common 50Hz or 60Hz AC motors, the frequency of the induced electromotive force is also 50Hz or 60Hz). The rectification and voltage stabilization circuit rectifies the alternating current generated by the induction coil into direct current and stores it in the energy storage device to supply power to the state detection sensor.

[0024] Magnetic flux is used to describe the total amount of magnetic field passing through a certain area. Suppose there is a plane with an area of S and perpendicular to the magnetic field direction in a uniform magnetic field with a magnetic induction intensity of B. The product of the magnetic induction intensity B and the area S is called the magnetic flux passing through this plane, simply referred to as magnetic flux, and is represented by the symbol Φ.

[0025] In the prior art, the state detection sensor is usually powered by a battery, and there is a technical problem of poor working reliability of the state detection sensor.

[0026] For a squirrel-cage induction motor, its rotor structure is relatively simple, the leakage magnetic flux is relatively small, and the proportion of leakage magnetic flux in the main magnetic flux is usually about 10% to 20%. For a wound-rotor induction motor: due to the presence of the rotor winding, the leakage magnetic flux path is increased, the leakage magnetic flux is relatively large, and the proportion of leakage magnetic flux in the main magnetic flux may be about 15% to 30%.

[0027] The power supply circuit of the state detection sensor in this embodiment generates a leakage magnetic field when the motor rotates by setting a magnetic flux ring on the motor. The leakage magnetic field generated by the motor will pass through the ring surface of the magnetic flux ring. Since the leakage magnetic field generated by the motor is a rotating magnetic field, the magnetic flux passing through the ring surface of the magnetic flux ring will change during the rotation of the leakage magnetic field, thereby generating an induced electromotive force (i.e., generating electrical energy) in the magnetic flux ring. By setting a rectification and voltage stabilization circuit and an energy storage device, the generated electrical energy is rectified, stored, and supplied to the state detection sensor in real time. The power supply circuit of the state detection sensor in this embodiment can use the leakage magnetic field generated during the operation of the motor to generate electrical energy in real time to supply power to the state detection sensor, thereby realizing stable and continuous power supply to the state detection sensor and ensuring the stability and reliability of the state detection sensor during operation. In addition, by setting an energy storage device to store the generated electrical energy, electrical energy waste is avoided. The power supply circuit of the state detection sensor in this embodiment does not use maintenance-consuming parts and does not require maintenance.

[0028] In one embodiment, the magnetic flux ring is installed on the axis or side of the motor and is located on the outer surface of the motor. When the magnetic flux ring is installed on the side of the motor, the positional relationship between the magnetic flux ring and the motor is as Figure 2 shown in the figure, where 1 is the magnetic flux ring and 2 is the motor.

[0029] By installing the magnetic flux ring on the axis or side of the motor, it is ensured that the magnetic flux ring efficiently collects the leakage magnetic field of the motor. By installing the magnetic flux ring on the outer surface of the motor, that is, non-invasive installation, the original structure of the motor is avoided from being changed.

[0030] In one embodiment, the rectification and voltage stabilization circuit uses an energy harvesting boost charging IC with the model number BQ25504; the energy storage device uses an energy storage battery.

[0031] As Figure 3 shown, the LBST pin of the BQ25504 chip is connected to one end of the inductor L, the other end of the inductor L is connected to the VIN_DC pin of the BQ25504 chip and grounded through the first capacitor C1, and the induction coil Q of the magnetic flux ring is connected in parallel across the two ends of the first capacitor C1. The VSTOR pin of the BQ25504 chip is grounded through the second capacitor C2, the VBAT pin is connected to the positive electrode of the energy storage battery Bat, and the negative electrode of the energy storage battery Bat is grounded. The positive and negative electrodes of the energy storage battery Bat are also connected to the state detection sensor to supply power to it.

[0032] As Figure 4 shown, the design method of the magnetic flux ring includes: S101. Determine the number of turns of the coil of the magnetic flux ring and the power generation power of the magnetic flux ring; According to the law of electromagnetic induction, .

[0033] Where E is the induced electromotive force (unit: V), f is the power supply frequency (unit: HZ), and N is the number of turns of the magnetic flux ring coil. is the maximum value of the leakage magnetic flux (unit: Wb).

[0034] It can be seen from this that the number of turns of the coil of the magnetic flux ring determines the magnitude of the induced electromotive force generated by the magnetic flux ring. Therefore, the number of turns of the coil of the magnetic flux ring can be determined according to the magnitude of the induced electromotive force required by the magnetic flux ring.

[0035] The power generation power of the magnetic flux ring can be determined according to the maximum stored charge of the energy storage device in the power supply circuit of the state detection sensor. The larger the maximum stored charge of the energy storage device, the greater the power generation power of the magnetic flux ring should be.

[0036] S102. Calculate the diameter of the magnetic flux ring based on the number of turns of the coil, the power generation power, the rotational speed and the number of pole pairs of the motor. The calculation expression is: ; In the formula, D represents the diameter of the magnetic flux ring, P represents the power generation power of the magnetic flux ring, R represents the load resistance of the magnetic flux ring, n represents the rotational speed of the motor, p represents the number of pole pairs of the motor, and k 1 and k 2 are constants.

[0037] Since the rotational speed of the motor may change during operation, in this embodiment, when calculating the diameter of the magnetic flux ring, let n take the rated rotational speed of the motor, that is, calculate the diameter of the magnetic flux ring based on the rated rotational speed of the motor.

[0038] k 1 and k 2 The values can be determined according to experiments. In this embodiment, the value range of k 1 is 0.00003 - 0.0001, and the value range of k 2 is 1.5 - 2.5.

[0039] The derivation process of the diameter calculation expression of the magnetic flux ring in this embodiment is as follows: A. According to Faraday's law of electromagnetic induction, the expression of the induced electromotive force is: ; In the formula, E is the induced electromotive force, N is the number of turns of the coil, is the rate of change of the magnetic flux.

[0040] B. When the motor is running, the change of the internal magnetic field will generate an induced electromotive force in the coil. Assume that the magnetic field of the motor is uniformly changing, and the magnetic flux (B is the magnetic induction intensity, and S is the cross-sectional area of the coil). For a given motor speed n (in revolutions per second), the change frequency of the magnetic flux (P is the number of pole pairs of the motor). Then the induced electromotive force (for an AC motor, is the magnetic flux amplitude).

[0041] C. Assume that the power generation power of the magnetic flux ring is P (unit: KW), the motor speed is n (unit: r / s), the number of pole pairs is p, the number of turns of the magnetic flux ring coil is N, the load resistance is R, and the diameter of the magnetic flux ring is D. According to the induced electromotive force formula ( ), and the power generation power formula , it can be deduced that . Since the size (diameter D) of the magnetic flux ring affects the magnetic flux, and the two are roughly positively correlated, it can be assumed that (k1 and k2 are coefficients to be determined). Substituting it into the power formula, we get: .

[0042] In the design method of the magnetic flux ring of this embodiment, when determining the diameter of the magnetic flux ring, first determine the number of turns of the magnetic flux ring coil and the expected power generation power of the magnetic flux ring, and then determine the diameter of the magnetic flux ring based on the number of turns of the magnetic flux ring coil and the expected power generation power of the magnetic flux ring. When determining the diameter of the magnetic flux ring, the relationship between the diameter of the magnetic flux ring, the number of turns of the coil, the expected power generation power, the load resistance of the magnetic flux ring, the speed and the number of pole pairs of the motor is comprehensively considered, so as to ensure that the power generation power of the designed magnetic flux ring meets the expected requirements.

[0043] In the above embodiments, the diameter of the magnetic flux ring is determined based on the number of turns of the magnetic flux ring coil and the power generation power. In one embodiment, the diameter of the magnetic flux ring can also be determined only based on the power generation power of the magnetic flux ring, and the following expression can be used for determination; ; In the formula, D represents the diameter of the magnetic flux ring, in mm, and P represents the power generation power of the magnetic flux ring.

[0044] By using the method for determining the diameter of the magnetic flux ring of this embodiment, the power generation power of the designed magnetic flux ring can be within the corresponding range.

[0045] In one embodiment, determining the number of turns of the magnetic flux ring coil includes: S201. Set the induced electromotive force of the magnetic flux ring , the coil current , the magnetic reluctance of the magnetic circuit , the winding resistance and the winding leakage inductance ; In this embodiment, the induced electromotive force The value range of is 0.13 - 3V. In other embodiments, it can also be set to other appropriate ranges.

[0046] In this embodiment, the coil current The value range of is 0.01 - 0.5A. In other embodiments, it can also be set to other appropriate values.

[0047] S202. Calculate the number of turns of the coil of the magnetic flux ring according to the induced electromotive force of the magnetic flux ring, the coil current, the magnetic reluctance of the magnetic circuit, and the leakage inductance of the winding in combination with the power supply frequency f of the motor , and the calculation expression is: .

[0048] In the formula, c is a constant; k is a correction coefficient considering the non - linearity of the iron core of the magnetic flux ring, and its value range is 0.00003 - 0.0001.

[0049] The number of turns of the coil of the magnetic flux ring in this embodiment The derivation process of the expression is as follows: (1) Determine the calculation formula of the induced electromotive force considering the influence of iron - core non - linearity: According to the electromagnetic induction law, the basic formula of the induced electromotive force is: . This formula shows that the induced electromotive force E is related to the power supply frequency f of the motor, the number of turns N of the magnetic flux ring coil, and the maximum value of the leakage magnetic flux . In an ideal case, this formula can be directly used to calculate the induced electromotive force. However, in actual situations, the coil permeability is not a constant value, and it changes with the magnetic field strength, especially showing a saturation phenomenon at high magnetic field strengths. To consider this non - linear influence of the iron core, a correction coefficient k is introduced in this embodiment, and the formula then becomes . By introducing the correction coefficient k, the calculation formula of the induced electromotive force is made more in line with the actual electromagnetic characteristics.

[0050] (2) Consider the influence of the winding resistance and leakage inductance of the magnetic flux ring and calculate the effective electromotive force: The winding resistance will cause a voltage drop. According to Ohm's law, the voltage drop generated by the current I passing through the winding resistance is ; at the same time, the winding leakage inductance will affect the induced electromotive force. In an AC circuit, the hindrance effect of the inductor on the current is represented by the inductive reactance, and the calculation expression of the inductive reactance is , then the influence of the leakage inductance on the electromotive force is . Therefore, the actual output electromotive force of the magnetic flux ring is: .

[0051] (3) Derive the functional relationship between the maximum value of the leakage magnetic flux and the current I by combining Ohm's law of magnetic circuit: The expression of Ohm's law of magnetic circuit is: , where F is the magnetomotive force, is the magnetic circuit impedance. During the electromagnetic induction process, the magnetic flux is related to the magnetomotive force and the magnetic resistance. Usually, the magnetomotive force is proportional to the current I. Therefore, let , then , where is a constant.

[0052] The specific value of can be determined by experiments.

[0053] (4) Derive the calculation expression of the number of turns of the coil of the magnetic flux ring: Substitute into to get . Then transform this formula to get: . Substitute the calculation formula of the electromotive force actually output by the magnetic flux ring obtained in step (2) to get .

[0054] In the design of the number of turns of the coil of the magnetic flux ring in this embodiment, it is considered that the magnetic permeability of the coil is not a constant and will change with the change of the magnetic field strength. Especially at high magnetic field strengths, saturation will occur, resulting in a change in the magnetic resistance of the magnetic circuit. A correction coefficient k is introduced to correct the calculation formula of the induced electromotive force; and the influence of the winding resistance and winding leakage inductance of the magnetic flux ring on the electromotive force output by the magnetic flux ring is considered, so as to ensure that the induced electromotive force generated by the designed magnetic flux ring during operation meets the expected requirements of the induced electromotive force and the expected power generation requirements, thereby providing reliable power supply for the state detection sensor. Although this specification has shown and described multiple embodiments of the present invention, it is obvious to those skilled in the art that such embodiments are provided only by way of example. Those skilled in the art will think of many changes, alterations, and alternative ways without departing from the spirit and scope of the present invention. It should be understood that various alternative solutions to the embodiments of the present invention described herein can be adopted in the practice of the present invention.

Claims

1. A power supply circuit for a state detection sensor, characterized in that: include: A magnetic flux ring, comprising a magnetic ring and an induction coil wound around the magnetic ring, is installed on the motor detected by the state detection sensor and is used to generate electric energy by utilizing the leakage magnetic field generated when the motor is working; A rectifier and voltage stabilizing circuit, whose input end is connected to the induction coil of the magnetic flux ring and whose output end is connected to the charging end of the energy storage device, is used to convert the electric energy generated by the magnetic flux ring into direct current and store it in the energy storage device; The output end of the energy storage device is connected to the state detection sensor for powering the state detection sensor.

2. The state detection sensor according to claim 1, characterized in that: The magnetic flux ring is installed in the axial direction or the side of the motor and is located on the outer surface of the motor.

3. The state detection sensor according to claim 1, characterized in that: The rectification and voltage stabilization circuit adopts an energy harvesting boost charging IC of model BQ25504.

4. The state detection sensor according to claim 1, characterized in that: The design method of the magnetic flux ring includes: Determine the number of coil turns of the flux loop and the power generated by the flux loop; The diameter of the magnetic flux ring is calculated according to the number of coil turns, the generated power, the rotational speed and the number of pole pairs of the motor, and the calculation expression is: ； In the formula, D represents the diameter of the flux loop, P represents the power generation of the flux loop, R represents the load resistance of the flux loop, n represents the rotation speed of the motor, p represents the number of pole pairs of the motor, and k1 and k2 are constants.

5. The state detection sensor according to claim 4, characterized in that: The value range of k1 is 0.00003-0.0001, and the value range of k2 is 1.5-2.

5.

6. The state detection sensor according to claim 1, characterized in that: Determining the number of coil turns for a flux loop involves: Set the induced electromotive force of the magnetic flux loop , coil current , magnetic circuit reluctance , Winding resistance And winding leakage inductance ; The number of coil turns of the magnetic flux loop is calculated based on the induced electromotive force of the magnetic flux loop, the coil current, the magnetic circuit reluctance and the winding leakage inductance combined with the power supply frequency f of the motor. , the calculation expression is: ； Where c is a constant; k is a correction coefficient for the nonlinearity of the core of the flux loop, and its value range is 0.00003-0.0001.

7. The state detection sensor according to claim 4, characterized in that: Induced electromotive force The value range is 0.13-3V.

8. The state detection sensor according to claim 4, characterized in that: Coil current The value range is 0.01-0.5A.

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