Design method, device and equipment of cross-linked cable arc-shaped magnetic core energy taking device

Abstract

The invention discloses a design method, device and equipment of a cross-linked cable arc-shaped magnetic core energy taking device, and belongs to the technical field of power system energy taking, and the method comprises the following steps: designing a magnetic core structure into an arc-shaped structure tightly attached to the surface of a cable, and increasing the physical length of the magnetic core structure; establishing a power model of magnetic field energy in an arc-shaped magnetic core saturation region based on the mutual inductance magnetic flux, and calculating the maximum output power; establishing a magnetization inductance model and an excitation current model, and calculating the energy taking capability of the arc-shaped magnetic core in the saturation region; and optimizing the number of turns of the coil based on the magnetization inductance model and the excitation current model. According to the invention, the complexity and time cost of magnetic core design are reduced, the highest power is obtained with the minimum magnetic core, the cost is reduced, and the practicability is enhanced. The invention provides an effective and high-precision magnetic core energy taking method, the use efficiency of the magnetic core is greatly improved, and meanwhile, a great influence is brought to the field of power transmission.

Description

Technical Field

[0001] The invention relates to a design method, a device and equipment for a cross-linked cable arc-shaped magnetic core energy harvesting device, belonging to the technical field of power system energy harvesting. Background Art

[0002] At present, energy harvesting technology has become a research hotspot because it can collect various forms of energy from the environment. It is one of the most promising and attractive power supply methods for wireless sensors. In recent years, energy harvesting technologies such as solar energy, wind energy, vibration, radio frequency, and magnetic field have been intensively studied.

[0003] Solar energy harvesters and wind energy harvesters are relatively mature. However, they are affected by weather conditions, which limits their applications. The output power of vibration energy harvesters and RF energy harvesters is extremely low, only at the μW level, which means that the power supply of some sensors cannot be maintained.

[0004] Independent non-closed core, it does not need a buckle, but can be placed on the cable, the core is non-closed, so it is more suitable for cables. But when it is applied to cables, it still needs to solve the key problem of low output power. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a design method, device and equipment for a cross-linked cable arc-shaped magnetic core energy extraction device, which can improve the use efficiency and energy extraction accuracy of the magnetic core.

[0006] The technical solution adopted by the present invention to solve the technical problem is: In a first aspect, an embodiment of the present invention provides a method for designing a cross-linked cable arc-shaped magnetic core energy extraction device, comprising the following steps: Step S1, designing the magnetic core structure into an arc-shaped structure that is close to the surface of the cable, while increasing its physical length; Step S2, establishing a power model of magnetic field energy in the arc core saturation region based on mutual induction flux (MIF), and calculating the maximum output power; Step S3, establishing a magnetizing inductance model (MIM) and an excitation current model (ECM) to calculate the energy extraction capability of the arc-shaped magnetic core in the saturation region; Step S4, optimizing the number of coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM).

[0007] As a possible implementation of this embodiment, the magnetic core structure is designed to be an arc-shaped structure that is close to the surface of the cable, while increasing its physical length, including the following steps: The mutual induction It is defined as the ratio of the magnetic flux at the acquisition coil to the cable current: , in, is the cross-sectional area through which the magnetic flux passes, is the number of turns of the coil; Considering the cable as an infinitely long conductor, when there is a magnetic core, the magnetic flux density Expressed as: , in, represents the magnetic permeability of vacuum, is the effective permeability of the core, is the distance from the core location to the cable; Effective permeability of the core Expressed as: , in, is the demagnetization coefficient of the core lamination, The smaller the magnetic flux density The bigger; Demagnetization coefficient is entirely determined by the core geometry, and The relationship with the core size is: , Where, L is the core length and D is the core diameter; The magnetic core structure is designed into an arc structure and adhered to the cable surface, while the length L of the magnetic core is increased.

[0008] As a possible implementation of this embodiment, the step of establishing a power model of magnetic field energy in a saturation region of an arc-shaped magnetic core based on mutual induction flux (MIF) and calculating the maximum output power includes the following steps: Assuming H is the magnetic field strength, representing the direction of the magnetic flux entering the core lamination, the magnetic flux actually converged by the core lamination is: , in, is the side length of the core layer, r is the radius, It is the vertical distance from any point on the laminate surface to its bottom; The core stack is a typical long straight core. Calculate the demagnetization coefficient of the core stack : , in, , , , Indicates the width of the magnetic core column; Calculate mutual inductance M: , Among them, k is the empirical coefficient, expressed as: , At the working angular frequency In the resonant state, the output power is: , , , , in, and are the currents flowing through the cable and the collection coil, respectively. is the internal resistance of the acquisition coil, is the equivalent AC load impedance, is the DC load impedance, is the coil induced voltage, is the resonant capacitor, is the forward voltage of the diode.

[0009] As a possible implementation of this embodiment, the establishment of a magnetizing inductance model (MIM) includes the following steps: The magnetic flux density of the core is expressed as: , in, For vacuum permeability, is the relative permeability, is the saturation flux density of the core material, For B to reach ± , H is the magnetic field strength; Calculate the magnetic flux by integrating: , in, is the outer diameter of the core, is the inner diameter of the core, is the excitation current of the magnetic core, is the height of the core, is the air gap width of the core wire; Calculate the magnetizing inductance (referring to the secondary side): , in is the number of winding turns.

[0010] As a possible implementation of this embodiment, the establishment of an excitation current model (ECM) includes the following steps: Calculate the voltage across the inductor : , in, is the magnetizing current, is the magnetizing inductance; The voltage across the inductor is clamped by the filter capacitor. Expressed as: , Among them, k is from arrive The slope of ; is the primary side current period, Square wave The amplitude of is the secondary side current The starting point, is the secondary side current The end point of By applying Kirchhoff's Current Law (KCL), the secondary side current is calculated : , in, is the magnetizing current, is the number of winding turns, is the primary side current; From time arrive Flow through The average current is expressed as: , in, is the magnetizing current, is the number of winding turns, is the primary side current, is the primary side current period; In time arrive During this time, the current absorbed by the inductor is equal to the current released by it, resulting in the following equation: , Then we get: .

[0011] As a possible implementation of this embodiment, the calculation formula for calculating the energy extraction capability of the arc-shaped magnetic core in the saturation region is: , in, for Voltage across both ends; is the unsaturated duration in a half cycle.

[0012] As a possible implementation of this embodiment, the optimization of the number of coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM) includes the following steps: For arc core, calculate the number of coil turns N: , in, Indicates the width of the core column, is the height of the coil, is the wire diameter, is the thickness of the insulation layer; Calculate the internal resistance of the acquisition coil : , in is the circumference of the outermost layer of the coil, is the conductivity of the coil wire; Calculating output power : , in, , ], is the side length of the core layer, r represents the radius, For vacuum permeability, is the effective permeability of the core, is the operating angular frequency, k is the empirical coefficient, is the current flowing through the cable.

[0013] In a second aspect, an embodiment of the present invention provides a design device for a cross-linked cable arc-shaped magnetic core energy extraction device, comprising: A magnetic core structure design module is used to design the magnetic core structure into an arc-shaped structure that fits closely to the cable surface while increasing its physical length; A power model building module, used to build a power model of magnetic field energy in the arc core saturation region based on mutual induction flux (MIF) and calculate the maximum output power; Energy extraction capacity calculation module, used to establish magnetizing inductance model (MIM) and excitation current model (ECM), and calculate the energy extraction capacity of the arc core in the saturation region; The coil turns optimization module is used to optimize the coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM).

[0014] As a possible implementation of this embodiment, the specific process of designing the magnetic core structure into an arc-shaped structure that is close to the cable surface and increasing its physical length is as follows: The mutual induction It is defined as the ratio of the magnetic flux at the acquisition coil to the cable current: , in, is the cross-sectional area through which the magnetic flux passes, is the number of turns of the coil; Considering the cable as an infinitely long conductor, when there is a magnetic core, the magnetic flux density Expressed as: , in, represents the magnetic permeability of vacuum, is the effective permeability of the core, is the distance from the core location to the cable; Effective permeability of the core Expressed as: , in, is the demagnetization coefficient of the core lamination, The smaller the magnetic flux density The bigger; Demagnetization coefficient is entirely determined by the core geometry, and The relationship with the core size is: , Where, L is the core length and D is the core diameter; The magnetic core structure is designed into an arc structure and adhered to the cable surface, while the length L of the magnetic core is increased.

[0015] As a possible implementation of this embodiment, the specific process of establishing a power model of the magnetic field energy in the saturation region of the arc-shaped magnetic core based on mutual induction flux (MIF) and calculating the maximum output power is as follows: Assuming H is the magnetic field strength, representing the direction of the magnetic flux entering the core lamination, the magnetic flux actually converged by the core lamination is: , in, is the side length of the core layer, r is the radius, It is the vertical distance from any point on the laminate surface to its bottom; The core stack is a typical long straight core. Calculate the demagnetization coefficient of the core stack : , in, , , , Indicates the width of the magnetic core column; Calculate mutual inductance M: , Among them, k is the empirical coefficient, expressed as: , At the working angular frequency In the resonant state, the output power is: , , , , in, and are the currents flowing through the cable and the collection coil, respectively. is the internal resistance of the acquisition coil, is the equivalent AC load impedance, is the DC load impedance, is the coil induced voltage, is the resonant capacitor, is the forward voltage of the diode.

[0016] As a possible implementation of this embodiment, the specific process of establishing the magnetizing inductance model (MIM) is as follows: The magnetic flux density of the core is expressed as: , in, For vacuum permeability, is the relative permeability, is the saturation flux density of the core material, For B to reach ± , H is the magnetic field strength; Calculate the magnetic flux by integrating: , in, is the outer diameter of the core, is the inner diameter of the core, is the excitation current of the magnetic core, is the height of the core, is the air gap width of the core wire; Calculate the magnetizing inductance (referring to the secondary side): , in is the number of winding turns.

[0017] As a possible implementation of this embodiment, the specific process of establishing the excitation current model (ECM) is: Calculate the voltage across the inductor : , in, is the magnetizing current, is the magnetizing inductance; The voltage across the inductor is clamped by the filter capacitor. Expressed as: , Among them, k is from arrive The slope of ; is the primary side current period, Square wave The amplitude of is the secondary side current The starting point, is the secondary side current The end point of By applying Kirchhoff's Current Law (KCL), the secondary side current is calculated : , in, is the magnetizing current, is the number of winding turns, is the primary side current; From time arrive Flow through The average current is expressed as: , in, is the magnetizing current, is the number of winding turns, is the primary side current, is the primary side current period; In time arrive During this time, the current absorbed by the inductor is equal to the current released by it, resulting in the following equation: , Then we get: .

[0018] As a possible implementation of this embodiment, the calculation formula for calculating the energy extraction capability of the arc-shaped magnetic core in the saturation region is: , in, for Voltage across both ends; is the unsaturated duration in a half cycle.

[0019] As a possible implementation of this embodiment, the specific process of optimizing the number of coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM) is as follows: For arc core, calculate the number of coil turns N: , in, Indicates the width of the core column, is the height of the coil, is the wire diameter, is the thickness of the insulation layer; Calculate the internal resistance of the acquisition coil : , in is the circumference of the outermost layer of the coil, is the conductivity of the coil wire; Calculating output power : , in, , ], is the side length of the core layer, r represents the radius, For vacuum permeability, is the effective permeability of the core, is the operating angular frequency, k is the empirical coefficient, is the current flowing through the cable.

[0020] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory through the bus, and the processor executes the machine-readable instructions to perform the design method steps of any cross-linked cable arc core energy extraction device as described above.

[0021] In a fourth aspect, an embodiment of the present invention provides a storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the design method of any cross-linked cable arc core energy harvesting device as described above are executed.

[0022] The beneficial effects of the technical solution of the embodiment of the present invention are as follows: The present invention increases the physical length of the core wire while the core wire is close to the cable surface, collects more magnetic field energy, and optimizes the coil turns design method, so that the energy extraction technology is further improved. The magnetic core design of the present invention can be designed without any simulation software, thereby effectively reducing the complexity and time cost of the magnetic core design, and obtaining the highest power with the smallest magnetic core, which means that the arc-shaped magnetic core effectively increases the output power of the magnetic core on the cable. At the same time, the minimum amount of magnetic core means that only lower costs are required, and the practicality is greatly enhanced. The present invention provides a new, effective, and high-precision magnetic core energy extraction method, which greatly improves the efficiency of the use of the magnetic core, and also has a significant impact on the field of power transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of a design method of a cross-linked cable arc-shaped magnetic core energy extraction device according to an exemplary embodiment; Figure 2 It is a structural schematic diagram of a design device for a cross-linked cable arc-shaped magnetic core energy extraction device according to an exemplary embodiment; Figure 3 is a diagram showing a structure of an arc-shaped magnetic core according to an exemplary embodiment; Figure 4 is a graph showing the variation of mutual inductance with the number of coil turns in different structures of the present invention; Figure 5 It is a curve diagram of output power variation with the change of the circumference of the outermost layer of the coil under different lamination sizes of the present invention; Figure 6 It is a curve showing the change of output power with the number of coil turns under different lamination sizes of the present invention. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the technical features of the solution of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0025] like Figure 1 As shown, a design method of a cross-linked cable arc-shaped magnetic core energy extraction device provided by an embodiment of the present invention comprises the following steps: Step S1, designing the magnetic core structure into an arc-shaped structure that is close to the surface of the cable, while increasing its physical length; Step S2, establishing a power model of magnetic field energy in the arc core saturation region based on mutual induction flux (MIF), and calculating the maximum output power; Step S3, establishing a magnetizing inductance model (MIM) and an excitation current model (ECM) to calculate the energy extraction capability of the arc-shaped magnetic core in the saturation region; Step S4, optimizing the number of coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM).

[0026] As a possible implementation of this embodiment, the magnetic core structure is designed to be an arc-shaped structure that is close to the surface of the cable, while increasing its physical length, including the following steps: The mutual induction It is defined as the ratio of the magnetic flux at the acquisition coil to the cable current: , in, is the cross-sectional area through which the magnetic flux passes, is the number of turns of the coil; Considering the cable as an infinitely long conductor, when there is a magnetic core, the magnetic flux density Expressed as: , in, represents the magnetic permeability of vacuum, is the effective permeability of the core, is the distance from the core location to the cable; Effective permeability of the core Expressed as: , in, is the demagnetization coefficient of the core lamination, The smaller the magnetic flux density The bigger; Demagnetization coefficient is entirely determined by the core geometry, and The relationship with the core size is: , Where, L is the core length and D is the core diameter; The magnetic core structure is designed into an arc structure and adhered to the cable surface, while the length L of the magnetic core is increased.

[0027] As a possible implementation of this embodiment, the step of establishing a power model of magnetic field energy in a saturation region of an arc-shaped magnetic core based on mutual induction flux (MIF) and calculating the maximum output power includes the following steps: Assuming H is the magnetic field strength, representing the direction of the magnetic flux entering the core lamination, the magnetic flux actually converged by the core lamination is: , in, is the side length of the core layer, r is the radius, It is the vertical distance from any point on the laminate surface to its bottom; The core stack is a typical long straight core. Calculate the demagnetization coefficient of the core stack : , in, , , , Indicates the width of the magnetic core column; Calculate mutual inductance M: , Among them, k is the empirical coefficient, expressed as: , At the working angular frequency In the resonant state, the output power is: , , , , in, and are the currents flowing through the cable and the collection coil, respectively. is the internal resistance of the acquisition coil, is the equivalent AC load impedance, is the DC load impedance, is the coil induced voltage, is the resonant capacitor, is the forward voltage of the diode.

[0028] As a possible implementation of this embodiment, the establishment of a magnetizing inductance model (MIM) includes the following steps: The magnetic flux density of the core is expressed as: , in, For vacuum permeability, is the relative permeability, is the saturation flux density of the core material, For B to reach ± , H is the magnetic field strength; Calculate the magnetic flux by integrating: , in, is the outer diameter of the core, is the inner diameter of the core, is the excitation current of the magnetic core, is the height of the core, is the air gap width of the core wire; Calculate the magnetizing inductance (referring to the secondary side): , in is the number of winding turns.

[0029] As a possible implementation of this embodiment, the establishment of an excitation current model (ECM) includes the following steps: Calculate the voltage across the inductor : , in, is the magnetizing current, is the magnetizing inductance; The voltage across the inductor is clamped by the filter capacitor. Expressed as: , Among them, k is from arrive The slope of ; is the primary side current period, Square wave The amplitude of is the secondary side current The starting point, is the secondary side current The end point of By applying Kirchhoff's Current Law (KCL), the secondary side current is calculated : , in, is the magnetizing current, is the number of winding turns, is the primary side current; From time arrive Flow through The average current is expressed as: , in, is the magnetizing current, is the number of winding turns, is the primary side current, is the primary side current period; In time arrive During this time, the current absorbed by the inductor is equal to the current released by it, resulting in the following equation: , Then we get: .

[0030] As a possible implementation of this embodiment, the calculation formula for calculating the energy extraction capability of the arc-shaped magnetic core in the saturation region is: , in, for Voltage across both ends; is the unsaturated duration in a half cycle.

[0031] As a possible implementation of this embodiment, the optimization of the number of coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM) includes the following steps: For arc core, calculate the number of coil turns N: , in, Indicates the width of the core column, is the height of the coil, is the wire diameter, is the thickness of the insulation layer; Calculate the internal resistance of the acquisition coil : , in is the circumference of the outermost layer of the coil, is the conductivity of the coil wire; Calculating output power : , in, , ], is the side length of the core layer, r represents the radius, For vacuum permeability, is the effective permeability of the core, is the operating angular frequency, k is the empirical coefficient, is the current flowing through the cable.

[0032] The present invention first designs the core structure into an arc-shaped structure that is close to the cable surface, while increasing its physical length; secondly, a power model of the magnetic field energy in the saturation region of the arc-shaped core based on mutual inductance flux (MIF) is established, and a magnetizing inductance model (MIM) and an excitation current model (ECM) are established to calculate the harvesting capacity of the arc-shaped core in the saturation region. Finally, based on the MIF and ECM models, a design method for optimizing the number of coil turns is proposed: when the actual core lamination size is less than the critical size, the coil must be fully wound to maximize the output power; and when the actual core lamination size is greater than or equal to the critical size, no matter what the core lamination size is, there is a fixed optimal number of turns to maximize the output power, that is, the number of coil turns of the coil winding corresponding to the critical core lamination size. The present invention provides a new, effective, and high-precision method for harvesting energy from a core, which greatly improves the efficiency of the use of the core, and also has a significant impact on the field of power transmission.

[0033] like Figure 2 As shown, a design device for a cross-linked cable arc-shaped magnetic core energy extraction device provided by an embodiment of the present invention includes: A magnetic core structure design module is used to design the magnetic core structure into an arc-shaped structure that fits closely to the cable surface while increasing its physical length; A power model building module, used to build a power model of magnetic field energy in the arc core saturation region based on mutual induction flux (MIF) and calculate the maximum output power; Energy extraction capacity calculation module, used to establish magnetizing inductance model (MIM) and excitation current model (ECM), and calculate the energy extraction capacity of the arc core in the saturation region; The coil turns optimization module is used to optimize the coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM).

[0034] As a possible implementation of this embodiment, the specific process of designing the magnetic core structure into an arc-shaped structure that is close to the cable surface and increasing its physical length is as follows: The mutual induction It is defined as the ratio of the magnetic flux at the acquisition coil to the cable current: , in, is the cross-sectional area through which the magnetic flux passes, is the number of turns of the coil; Considering the cable as an infinitely long conductor, when there is a magnetic core, the magnetic flux density Expressed as: , in, represents the magnetic permeability of vacuum, is the effective permeability of the core, is the distance from the core location to the cable; Effective permeability of the core Expressed as: , in, is the demagnetization coefficient of the core lamination, The smaller the magnetic flux density The bigger; Demagnetization coefficient is entirely determined by the core geometry, and The relationship with the core size is: , Where, L is the core length and D is the core diameter; The magnetic core structure is designed into an arc structure and adhered to the cable surface, while the length L of the magnetic core is increased.

[0035] As a possible implementation of this embodiment, the specific process of establishing a power model of the magnetic field energy in the saturation region of the arc-shaped magnetic core based on mutual induction flux (MIF) and calculating the maximum output power is as follows: Assuming H is the magnetic field strength, representing the direction of the magnetic flux entering the core lamination, the magnetic flux actually converged by the core lamination is: , in, is the side length of the core layer, r is the radius, It is the vertical distance from any point on the laminate surface to its bottom; The core stack is a typical long straight core. Calculate the demagnetization coefficient of the core stack : , in, , , , Indicates the width of the magnetic core column; Calculate mutual inductance M: , Among them, k is the empirical coefficient, expressed as: , At the working angular frequency In the resonant state, the output power is: , , , , in, and are the currents flowing through the cable and the collection coil, respectively. is the internal resistance of the acquisition coil, is the equivalent AC load impedance, is the DC load impedance, is the coil induced voltage, is the resonant capacitor, is the forward voltage of the diode.

[0036] As a possible implementation of this embodiment, the specific process of establishing the magnetizing inductance model (MIM) is as follows: The magnetic flux density of the core is expressed as: , in, For vacuum permeability, is the relative permeability, is the saturation flux density of the core material, For B to reach ± , H is the magnetic field strength; Calculate the magnetic flux by integrating: , in, is the outer diameter of the core, is the inner diameter of the core, is the excitation current of the magnetic core, is the height of the core, is the air gap width of the core wire; Calculate the magnetizing inductance (referring to the secondary side): , in is the number of winding turns.

[0037] As a possible implementation of this embodiment, the specific process of establishing the excitation current model (ECM) is: Calculate the voltage across the inductor : , in, is the magnetizing current, is the magnetizing inductance; The voltage across the inductor is clamped by the filter capacitor. Expressed as: , Among them, k is from arrive The slope of ; is the primary side current period, Square wave The amplitude of is the secondary side current The starting point, is the secondary side current The end point of By applying Kirchhoff's Current Law (KCL), the secondary side current is calculated : , in, is the magnetizing current, is the number of winding turns, is the primary side current; From time arrive Flow through The average current is expressed as: , in, is the magnetizing current, is the number of winding turns, is the primary side current, is the primary side current period; In time arrive During this time, the current absorbed by the inductor is equal to the current released by it, resulting in the following equation: , Then we get: .

[0038] As a possible implementation of this embodiment, the calculation formula for calculating the energy extraction capability of the arc-shaped magnetic core in the saturation region is: , in, for Voltage across both ends; is the unsaturated duration in a half cycle.

[0039] As a possible implementation of this embodiment, the specific process of optimizing the number of coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM) is as follows: For arc core, calculate the number of coil turns N: , in, Indicates the width of the core column, is the height of the coil, is the wire diameter, is the thickness of the insulation layer; Calculate the internal resistance of the acquisition coil : , in is the circumference of the outermost layer of the coil, is the conductivity of the coil wire; Calculating output power : , in, , ], is the side length of the core layer, r represents the radius, For vacuum permeability, is the effective permeability of the core, is the operating angular frequency, k is the empirical coefficient, is the current flowing through the cable.

[0040] A high-voltage current generator was used to generate 50Hz alternating current to simulate the current in the cable, and 1J85, which is easy to process into various shapes and has a relative magnetic permeability of about 100,000, was selected as the core material. In order to verify the law of the optimal number of coil turns N, experiments were conducted on different core lamination sizes.

[0041] Step 1: Design the core structure into an arc-shaped structure that fits closely to the cable surface while increasing its physical length.

[0042] Mutual Induction It is defined as the ratio of the magnetic flux at the acquisition coil to the cable current and can be calculated as follows: , in, is the cross-sectional area through which the magnetic flux passes, is the number of turns of the coil; Considering the cable as an infinitely long conductor, when there is a magnetic core, the magnetic flux density It can be expressed as: , in, represents the magnetic permeability of vacuum, is the effective permeability of the core, is the distance from the core location to the cable; Expressed as: , The smaller the The bigger; is entirely determined by the core geometry, and The relationship with the core size can be summarized as: , Where L is the length of the core and D is the diameter of the core.

[0043] The core structure is designed to be an arc structure such as Figure 3 As shown in the figure, the arc-shaped design makes the core adhere to the cable surface as a whole. Since the magnetic field intensity on the cable surface is the largest, the magnetic flux can be converged to the maximum extent. Figure 4 As shown, is the mutual inductance curve of the arc core, is the mutual inductance of the H-shaped core. The mutual inductance of the arc core is always significantly higher than that of the H-shaped core system.

[0044] Step 2: Establish a power model of the magnetic field energy in the saturation region of the arc core based on mutual induction flux (MIF) to find the maximum output power.

[0045] Assuming H is the magnetic field strength, it represents the direction of the magnetic flux entering the core lamination; the magnetic flux actually converged by the core lamination can be expressed as: , in, is the lamination size, r is the radius, It is the vertical distance from any point on the laminate surface to its bottom.

[0046] The core lamination is a typical long straight core, and the demagnetization coefficient of the core lamination is Expressed as: , in, , , , Indicates the width of the core column.

[0047] Then the mutual inductance M can be expressed as: , Where k is the empirical coefficient, which can be expressed as: .

[0048] In the process of non-closed core powering the sensor on the cable, represents the self-inductance of the acquisition coil; and are the currents flowing through the cable and the collection coil respectively; is the internal resistance of the acquisition coil, is the equivalent AC load impedance, and is the DC load impedance, and they satisfy the relationship ; is the coil induced voltage, is the resonant capacitor, is the forward voltage of the diode; the system is set at the operating angular frequency The lower part is in resonance state; and It is expressed as: , , The output power of the system is: , Output Power Influenced by I, R and M.

[0049] The current in the cable is determined by the load power and cannot be adjusted arbitrarily. When R is fixed, the output power can only be increased by increasing M. M is related to the size of the iron core, the lamination distance from the iron core to the copper core, the number of turns of the coil, etc.

[0050] Step 3: Establish a magnetizing inductance model (MIM) and an excitation current model (ECM) to calculate the energy extraction capability of the arc core in the saturation region.

[0051] The specific process of establishing the magnetizing inductance model (MIM) is as follows.

[0052] The magnetic flux density of the core can be expressed as follows: , in, Vacuum permeability, Relative permeability, The saturation flux density of the core material, For B to reach ± , H is the magnetic field strength; The magnetic flux is obtained by integration: , in, is the outer diameter of the core, is the inner diameter of the core, is the excitation current of the magnetic core, is the height of the core, is the air gap width of the core wire; The magnetizing inductance (referring to the secondary side) can be expressed as: , in is the number of winding turns.

[0053] Relative magnetic permeability It is regarded as a constant in the unsaturated stage and is approximately zero in the saturated stage. can be regarded as a constant value; in the saturation stage, Almost zero.

[0054] The specific process of establishing the ECM model to calculate the energy extraction capability of the arc core in the saturation region is as follows.

[0055] The voltage across the inductor It can be expressed as: , in, is the magnetizing current, is the magnetizing inductance; Affected by the clamping of the filter capacitor, it can be expressed as: , Among them, k is from arrive The slope of ; is the primary side current period, Square wave The amplitude of is the secondary side current The starting point, is the secondary side current The end point of By applying Kirchhoff's current law (KCL), the secondary side current It can be expressed as: , in, is the magnetizing current, is the number of winding turns, is the primary side current; From time arrive Flow through The average current can be expressed as: , in, is the magnetizing current, is the number of winding turns, is the primary side current, is the primary side current cycle; at time arrive During this period, the current absorbed by the inductor is equal to the current released by it, and the following equation can be obtained: , From the above formula, we can get: , From the above formula, the average energy extraction capacity is: , in, for Voltage across both ends; is the unsaturated duration in a half cycle.

[0056] Step S4, optimizing the number of coil turns based on the magnetizing inductance model (MIM) and the excitation current model (ECM).

[0057] For an arc core, N (number of coil turns) can be expressed as: , in, Indicates the width of the core column, is the height of the coil, is the wire diameter, is the thickness of the insulation layer; It can be expressed as: , in, is the circumference of the outermost layer of the coil, is the conductivity of the coil wire, the output power It can be expressed as: , in, , ]. Under different lamination sizes, the output power variation curve with the change of the circumference of the outermost layer of the coil, such as Figure 5 shown.

[0058] The experimental results are shown in Figure 6The experimental results are consistent with the theoretical predictions, and the optimal N value is indeed related to the critical size of the core laminations. When the lamination size is 1 cm, which is smaller than the critical size of 1.3 cm, N should be increased as much as possible to maximize the output power. When N is 10,000, the maximum power reaches 22.2 mW, which is about 13 times higher than the minimum power of 1.7 mW when N is 2,000. When the lamination size is 2 cm or 3 cm, which is larger than the critical size, the output power increases first and then decreases with the increase of N, indicating that there is a fixed optimal number of turns N, and regardless of whether the lamination size is 2 cm or 3 cm, the optimal number of turns is 30,000. It is worth noting that due to reasons such as manual winding, there is an inevitable error between the optimal number of turns obtained in the experiment (30,000) and the optimal number of turns calculated theoretically (31,883).

[0059] The present invention proposes a method for harvesting energy from a cross-linked cable arc core based on magnetic flux collection enhancement (MFCE). First, the core structure is designed to be an arc structure that is close to the cable surface, while increasing its physical length. Secondly, a power model of the magnetic field energy in the saturation region of the arc core based on MIF is established, and the MIF and ECM models are established to calculate the harvesting capacity of the arc core in the saturation region. Finally, based on the MIF and ECM models, a new design method for optimizing the number of coil turns is proposed: when the actual core lamination size is less than the critical size, the coil must be fully wound to maximize the output power; and when the actual core lamination size is greater than or equal to the critical size, no matter what the core lamination size is, there is a fixed optimal number of turns to maximize the output power, that is, the number of coil turns corresponding to the critical core lamination size of the coil winding.

[0060] The error between the experimental results of the present invention and the theoretical value of the optimal number of turns is extremely small, which effectively reduces the complexity and time cost of the magnetic core design, and the arc-shaped magnetic core effectively increases the output power of the magnetic core on the cable. At the same time, the minimum amount of magnetic core means that only lower costs are required, and the practicality is greatly enhanced.

[0061] An embodiment of the present invention provides an electronic device, including a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory through the bus, and the processor executes the machine-readable instructions to perform the design method steps of any cross-linked cable arc core energy extraction device as described above.

[0062] Specifically, the above-mentioned memory and processor can be general-purpose memory and processor, which are not specifically limited here. When the processor runs the computer program stored in the memory, it can execute the above-mentioned design method of the cross-linked cable arc-shaped magnetic core energy extraction device.

[0063] Corresponding to the startup method of the above-mentioned application, an embodiment of the present invention further provides a storage medium on which a computer program is stored. When the computer program is run by a processor, the design method steps of any cross-linked cable arc core energy extraction device as described above are executed.

[0064] 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 above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A design method for a cross-linked cable arc core energy extraction device, characterized in that: The steps include: Step S1, designing the magnetic core structure into an arc-shaped structure that is close to the surface of the cable, while increasing its physical length; Step S2, establishing a power model of magnetic field energy in a saturation region of an arc-shaped magnetic core based on mutual inductance magnetic flux, and calculating the maximum output power; Step S3, establishing a magnetizing inductance model and an excitation current model, and calculating the energy extraction capability of the arc-shaped magnetic core in the saturation region; Step S4, optimizing the number of coil turns based on the magnetizing inductance model and the excitation current model.

2. The design method of the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 1 is characterized in that: The method of designing the magnetic core structure into an arc-shaped structure that is close to the surface of the cable and increasing its physical length comprises the following steps: The mutual induction It is defined as the ratio of the magnetic flux at the acquisition coil to the cable current: ， in, is the cross-sectional area through which the magnetic flux passes, is the number of turns of the coil; Considering the cable as an infinitely long conductor, when there is a magnetic core, the magnetic flux density Expressed as: ， in, represents the magnetic permeability of vacuum, is the effective permeability of the core, is the distance from the core location to the cable; Effective permeability of the core Expressed as: ， in, is the demagnetization coefficient of the core lamination, The smaller the magnetic flux density The bigger; Demagnetization coefficient is entirely determined by the core geometry, and The relationship with the core size is: Where, L is the core length and D is the core diameter; The magnetic core structure is designed into an arc structure and adhered to the cable surface, while the length L of the magnetic core is increased.

3. The design method of the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 1 is characterized in that: The method of establishing a power model of magnetic field energy in a saturation region of an arc-shaped magnetic core based on mutual inductance magnetic flux and calculating the maximum output power comprises the following steps: Assuming H is the magnetic field strength, representing the direction of the magnetic flux entering the core lamination, the magnetic flux actually converged by the core lamination is: ， in, is the side length of the core layer, r is the radius, It is the vertical distance from any point on the laminate surface to its bottom; Calculate the demagnetization coefficient of the core stack : ， in, , , , Indicates the width of the magnetic core column; Calculate mutual inductance M: ， Among them, k is the empirical coefficient, expressed as: ， At the working angular frequency In the resonant state, the output power is: ， ， ， ， in, and are the currents flowing through the cable and the collection coil, respectively. is the internal resistance of the acquisition coil, is the equivalent AC load impedance, is the DC load impedance, is the coil induced voltage, is the resonant capacitor, is the forward voltage of the diode.

4. The design method of the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 1 is characterized in that: The establishment of the magnetizing inductance model comprises the following steps: The magnetic flux density of the core is expressed as: ， in, For vacuum permeability, is the relative permeability, is the saturation flux density of the core material, For B to reach ± , H is the magnetic field strength; Calculate the magnetic flux by integrating: ， in, is the outer diameter of the core, is the inner diameter of the core, is the excitation current of the magnetic core, is the height of the core, is the air gap width of the core wire; Calculate the magnetizing inductance: ， in is the number of winding turns.

5. The design method of the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 1 is characterized in that: The step of establishing the excitation current model comprises the following steps: Calculate the voltage across the inductor : ， in, is the magnetizing current, is the magnetizing inductance; The voltage across the inductor is clamped by the filter capacitor. Expressed as: ， Among them, k is from arrive The slope of ; is the primary side current period, Square wave The amplitude of is the secondary side current The starting point, is the secondary side current The end point of By applying Kirchhoff's current law, the secondary side current is calculated : ， in, is the magnetizing current, is the number of winding turns, is the primary side current; From time arrive Flow through The average current is expressed as: ， in, is the magnetizing current, is the number of winding turns, is the primary side current, is the primary side current period; In time arrive During this time, the current absorbed by the inductor is equal to the current released by it, resulting in the following equation: ， Then we get: 。 6. The design method of the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 5 is characterized in that: The calculation formula for calculating the energy extraction capability of the arc-shaped magnetic core in the saturation region is: ， in, for Voltage across both ends; is the unsaturated duration in a half cycle.

7. The design method of the cross-linked cable arc-shaped magnetic core energy extraction device according to any one of claims 1 to 6, characterized in that: The method of optimizing the number of coil turns based on the magnetizing inductance model and the excitation current model comprises the following steps: For arc core, calculate the number of coil turns N: ， in, Indicates the width of the core column, is the height of the coil, is the wire diameter, is the thickness of the insulation layer; Calculate the internal resistance of the acquisition coil : ， in is the circumference of the outermost layer of the coil, is the conductivity of the coil wire; Calculating output power : ， in, , ], is the side length of the core layer, r represents the radius, For vacuum permeability, is the effective permeability of the core, is the operating angular frequency, k is the empirical coefficient, is the current flowing through the cable.

8. A design device for a cross-linked cable arc core energy extraction device, characterized in that: include: A magnetic core structure design module is used to design the magnetic core structure into an arc-shaped structure that fits closely to the cable surface while increasing its physical length; A power model building module is used to build a power model of magnetic field energy in a saturation region of an arc-shaped magnetic core based on mutual inductance magnetic flux and calculate the maximum output power; Energy extraction capacity calculation module, used to establish magnetizing inductance model and excitation current model, and calculate the energy extraction capacity of arc core in saturation region; The coil turns optimization module is used to optimize the coil turns based on the magnetizing inductance model and the excitation current model.

9. The design device for the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 8, characterized in that: The specific process of designing the magnetic core structure into an arc-shaped structure that is close to the cable surface and increasing its physical length is as follows: The mutual induction It is defined as the ratio of the magnetic flux at the acquisition coil to the cable current: ， in, is the cross-sectional area through which the magnetic flux passes, is the number of turns of the coil; Considering the cable as an infinitely long conductor, when there is a magnetic core, the magnetic flux density Expressed as: ， in, represents the magnetic permeability of vacuum, is the effective permeability of the core, is the distance from the core location to the cable; Effective permeability of the core Expressed as: ， in, is the demagnetization coefficient of the core lamination, The smaller the magnetic flux density The bigger; Demagnetization coefficient is entirely determined by the core geometry, and The relationship with the core size is: ， Where, L is the core length and D is the core diameter; The magnetic core structure is designed into an arc structure and adhered to the cable surface, while the length L of the magnetic core is increased.

10. The design device for the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 8, characterized in that: The specific process of establishing the power model of the magnetic field energy in the arc core saturation region based on the mutual inductance magnetic flux and calculating the maximum output power is as follows: Assuming H is the magnetic field strength, representing the direction of the magnetic flux entering the core lamination, the magnetic flux actually converged by the core lamination is: ， in, is the side length of the core layer, r is the radius, It is the vertical distance from any point on the laminate surface to its bottom; Calculate the demagnetization coefficient of the core stack : ， in, , , , Indicates the width of the magnetic core column; Calculate mutual inductance M: ， Among them, k is the empirical coefficient, expressed as: ， At the working angular frequency In the resonant state, the output power is: ， ， ， ， in, and are the currents flowing through the cable and the collection coil, respectively. is the internal resistance of the acquisition coil, is the equivalent AC load impedance, is the DC load impedance, is the coil induced voltage, is the resonant capacitor, is the forward voltage of the diode.

11. The design device of the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 8, characterized in that: The specific process of establishing the magnetizing inductance model is as follows: The magnetic flux density of the core is expressed as: ， in, For vacuum permeability, is the relative permeability, is the saturation flux density of the core material, For B to reach ± , H is the magnetic field strength; Calculate the magnetic flux by integrating: ， in, is the outer diameter of the core, is the inner diameter of the core, is the excitation current of the magnetic core, is the height of the core, is the air gap width of the core wire; Calculate the magnetizing inductance: ， in is the number of winding turns.

12. The design device for the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 8, characterized in that: The specific process of establishing the excitation current model is: Calculate the voltage across the inductor : ， in, is the magnetizing current, is the magnetizing inductance; The voltage across the inductor is clamped by the filter capacitor. Expressed as: ， Among them, k is from arrive The slope of ; is the primary side current period, Square wave The amplitude of is the secondary side current The starting point, is the secondary side current The end point of By applying Kirchhoff's current law, the secondary side current is calculated : ， in, is the magnetizing current, is the number of winding turns, is the primary side current; From time arrive Flow through The average current is expressed as: ， in, is the magnetizing current, is the number of winding turns, is the primary side current, is the primary side current period; In time arrive During this time, the current absorbed by the inductor is equal to the current released by it, resulting in the following equation: ， Then we get: 。 13. The design device of the cross-linked cable arc-shaped magnetic core energy extraction device according to claim 12, characterized in that: The calculation formula for calculating the energy extraction capability of the arc-shaped magnetic core in the saturation region is: ， in, for Voltage across both ends; is the unsaturated duration in a half cycle.

14. The design device of the cross-linked cable arc core energy extraction device according to any one of claims 8 to 13, characterized in that: The specific process of optimizing the number of coil turns based on the magnetizing inductance model and the excitation current model is as follows: For arc core, calculate the number of coil turns N: ， in, Indicates the width of the core column, is the height of the coil, is the wire diameter, is the thickness of the insulation layer; Calculate the internal resistance of the acquisition coil : ， in is the circumference of the outermost layer of the coil, is the conductivity of the coil wire; Calculating output power : ， in, , ], is the side length of the core layer, r represents the radius, For vacuum permeability, is the effective permeability of the core, is the operating angular frequency, k is the empirical coefficient, is the current flowing through the cable.

15. An electronic device, characterized in that: It includes a processor, a memory and a bus, the memory stores machine-readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and the processor executes the machine-readable instructions to perform the design method steps of the cross-linked cable arc magnetic core energy extraction device as described in any one of claims 1-7.

16. A storage medium, characterized in that: The storage medium stores a computer program, which, when executed by a processor, executes the steps of the design method for the cross-linked cable arc-shaped magnetic core energy harvesting device as claimed in any one of claims 1 to 7.

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