CN114865802A - Induction electricity taking device of non-closed magnetic core - Google Patents

Abstract

The present invention provides a non-closed magnetic core inductive power take-off device, comprising a non-closed magnetic core coil assembly that can be drawn and a power management module connected thereto, wherein the retractable magnetic core coil assembly includes a plurality of thin cylindrical coil components. The magnetic core and a magnetic core coil sleeved on the outer side of all the thin cylindrical magnetic cores, at least a part of the thin cylindrical magnetic core can be twitched relative to the magnetic core coil. The inductive power taking device of the non-closed magnetic core of the present invention adopts a non-closed magnetic core, which solves the problem that the inductive power taking device is compatible with different voltage levels and cable diameters. The magnetic core can be twitched to change the length of the magnetic circuit in the magnetic core, so that the output power and power density of the overall magnetic core can be improved.

Description

A non-closed magnetic core inductive power take-off device

technical field

The invention belongs to the technical field of inductive power taking, and more particularly, relates to an inductive power taking device with a non-closed magnetic core.

Background technique

At present, with the proposal of the dual carbon goal, the development of a new power system with intelligent sensing capability is a key link, and a large number of wireless sensors are the key to achieving "comprehensive sensing and interconnection". The power supply problem of the power sensor is the core module that restricts its large-scale application. The power supply methods for power online monitoring sensors mainly include battery power supply, solar power supply, laser power supply, resonant coupling power supply, vibration power supply, capacitive partial pressure power supply, magnetic field induction power supply, etc. Inductive power supply is due to its stability and stability. Maturity is the most widely used.

At present, for the alternating magnetic field generated by the AC cables and lines, the most commonly used magnetic induction power-taking method is CT (Current Transformer, current transformer) power-taking. The inductive power taking module mainly uses the current transformer to directly induce the AC voltage from the high-voltage bus, and then undergoes rectification, filtering, and voltage stabilization to obtain a stable and reliable DC voltage, which provides a stable power supply for the sensors installed nearby, which can ensure its Long-term stable power supply.

The composition of the inductive power taking module mainly includes a current transformer and a back-end processing circuit. Among them, the core components of the current transformer are the magnetic core and the coil. Their function is to concentrate the magnetic flux and improve the efficiency and reliability of electricity extraction. Since the current carrying capacity of the AC cable changes with the load and other factors, when the current carrying capacity is small, the power taken by the CT magnetic core coil is low, and there is a dead zone for energy taking. , and also have an impact on the subsequent circuit.

In order to protect the power take-off device, a split-type CT has appeared, which has a split-type magnetic core, but its magnetic core needs to be designed according to the corresponding cable size, and it cannot be applied to cables of different voltage levels, which reduces the universality of the power take-off device. , it is impossible to quickly install and supply energy, and the open-close magnetic core is composed of upper and lower magnetic cores. The magnetic core is prone to displacement when the sealant is poured, resulting in problems such as false touch due to asymmetry of the magnetic core when the device is closed.

The existing non-closed magnetic core induction power taking device can protect the power taking device and avoid the problem of false touch when the device is closed, but its disadvantage is that the output power of the power taking device is too low.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a non-closed magnetic core induction power taking device, so as to improve the universality and output power while protecting the power taking device.

In order to achieve the above object, the present invention provides a non-closed magnetic core inductive power take-off device, comprising a non-closed magnetic core coil assembly that can be pulled and a power management module connected to it, wherein the retractable magnetic core coil assembly includes A plurality of thin cylindrical magnetic cores and a magnetic core coil sleeved on the outer side of all thin cylindrical magnetic cores, at least a part of the thin cylindrical magnetic cores can be twitched relative to the magnetic core coils.

At least a part of the adjacent thin cylindrical magnetic cores are attached to each other in parallel, and the arrangement direction of the plurality of thin cylindrical magnetic cores is parallel to the extension direction of the cables to be collected.

The drawable magnetic core coil assembly is a linear drawable magnetic core coil assembly, and the thin cylindrical magnetic core only includes a linear thin cylindrical magnetic core whose overall shape is straight.

The number of the straight thin cylindrical magnetic cores is seven.

The drawable magnetic core coil assembly is a right-angle drawable magnetic core coil assembly, and the thin cylindrical magnetic core includes a plurality of linear thin cylindrical magnetic cores with an overall shape of a straight line and a plurality of straight thin cylindrical magnetic cores with an overall shape from a right-angle vertex to the direction. Right-angled slender core with two line segments extending outward.

The number of the straight thin cylindrical magnetic cores is 8, and the number of the right angle thin cylindrical magnetic cores is three.

The cross-sectional shape of the thin cylindrical magnetic core is circular.

The magnetic core coil has two ports, and both ports of the magnetic core coil are connected to the power management module; one port of the magnetic core coil is connected in series with a capacitor, and is connected to the power management module through the capacitor, or the The core coil is connected in parallel with a capacitor.

The material of the magnetic core coil is pure copper.

The material of the thin cylindrical magnetic core is permalloy with an initial relative magnetic permeability of 50,000.

The inductive power taking device of the non-closed magnetic core of the present invention adopts the non-closed magnetic core, and equivalently replaces the traditional whole magnetic core with several thin magnetic cores with higher effective magnetic permeability, and the magnetic core can be twitched to change The length of the magnetic circuit in the magnetic core can improve the output power and power density of the overall magnetic core, and the different extraction lengths of the magnetic core solve the problem of compatibility between different voltage levels and cable diameters of the induction power-taking device. In addition, the capacitor provided in the non-closed magnetic core of the present invention adopts the resonance principle to eliminate the coil self-inductance and improve the output efficiency.

Description of drawings

FIG. 1 is a schematic structural diagram of a non-closed magnetic core induction power taking device according to a first embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a linear pullable magnetic core coil assembly of the non-closed magnetic core induction power taking device according to the first embodiment of the present invention.

3 is a schematic cross-sectional view of a linear pullable magnetic core coil assembly of the non-closed magnetic core induction power taking device according to the first embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a non-closed magnetic core induction power taking device according to a second embodiment of the present invention.

5 is a schematic structural diagram of a right-angle movable magnetic core coil assembly of a non-closed magnetic core induction power taking device according to Embodiment 2 of the present invention.

Detailed ways

The invention provides a non-closed magnetic core induction power taking device, which comprises a non-closed magnetic core coil assembly that can be drawn and a power management module connected to it. In the present invention, the drawable core coil assembly may be a linear drawable core coil assembly or a right-angle drawable core coil assembly.

Embodiment 1 Non-closed magnetic core induction power take-off device with linear pullable magnetic core coil assembly

As shown in FIG. 1 , the non-closed magnetic core induction power taking device of the present invention includes a linear drawable magnetic core coil assembly 1 and a power management module 2 connected to the linear drawable magnetic core coil assembly 1 . Among them, the linear movable magnetic core coil assembly 1 is clamped to the surface of the cable to be collected, and is set to convert the magnetic energy of the cable to be collected into the output signal of the linear movable magnetic core coil assembly 1; the power management module 2 and the sensor load It is used to convert the output signal of the linear twitchable magnetic core coil assembly 1 into a stable power supply voltage, so as to provide the sensor load.

As shown in FIG. 2 , the linear drawable magnetic core coil assembly 1 includes a plurality of thin cylindrical magnetic cores 3 and a magnetic core coil 4 sleeved on the outer side of all thin cylindrical magnetic cores 3 . At least a portion of the core 3 is twitchable relative to the core coil 4 . At least a part of the adjacent thin cylindrical magnetic cores 3 are attached together in parallel with each other, and the arrangement direction of the plurality of thin cylindrical magnetic cores 3 is parallel to the extension direction of the cable to be collected, so as to better fit the to-be-collected cable. surface of the cable.

Among them, in order to further improve the power density, the linear twitchable magnetic core coil assembly 1 adopts a twitching structure design, that is, a plurality of twitchable thin cylindrical magnetic cores 3 are used. 3. The relative displacement is performed, and the magnetic core coil 4 is moved outward for a certain distance to increase the length of the magnetic circuit in the magnetic core, and a larger magnetic density can be obtained. The specific distance that the thin cylindrical magnetic core 3 moves outward is determined according to the output power results measured experimentally, so as to achieve the maximum output power.

The thin-column core 3 is made of permalloy with an initial relative permeability of 50,000, and its cross-sectional area and length can be adjusted according to the size and current-carrying capacity of the object to be measured, such as the cable to be collected. Under the circumstance that the cross-sectional area and length of the thin cylindrical magnetic core 3 have been given by design, the extraction length of the magnetic core can be adaptively changed according to the size and current carrying capacity of the cable to be collected, so that the different extraction of the magnetic core can be achieved. The length solves the problem of compatibility between different voltage levels and cable diameters of inductive power take-off devices. .

As shown in FIG. 3 , in this embodiment, the slender columnar magnetic cores 3 only include straight slender columnar magnetic cores whose overall shape is straight, and the number of the slender columnar magnetic cores 3 is seven. The cross-sectional shape of the slender columnar magnetic core 3 is circular. For the slender columnar magnetic core 3 with a circular cross-sectional shape, after the relative magnetic permeability is determined, the effective magnetic permeability is only related to the ratio of height to diameter. The greater the effective magnetic permeability of the magnetic core, therefore, the present invention adopts 7 thin cylindrical magnetic cores whose overall shape is a straight line to replace the commonly used cuboid magnetic core, and obtains a linear magnetic core group with high effective magnetic permeability to improve the power density.

The material of the magnetic core coil 4 is pure copper, and the coil diameter and the number of turns can be adjusted according to the requirements of the object to be measured, such as the cable to be collected. The magnetic core coil 4 has two ports, and both ports of the magnetic core coil 4 are connected to the power management module.

One port of the magnetic core coil 4 is connected in series with a capacitor (not shown), and is connected to the power management module 2 through the capacitor; or the magnetic core coil 4 is connected in parallel with a capacitor (ie, both ports are connected to the capacitor). The capacitor is matched with the reactance of the coil itself, thereby reducing the power loss of the coil inductance to improve the power acquisition and transmission efficiency. The resonance principle is adopted to eliminate the coil self-inductance, and the output power is improved.

Embodiment 2 Non-closed magnetic core induction power take-off device with right-angle twitchable magnetic core coil assembly

As shown in FIG. 4 , the non-closed magnetic core induction power take-off device includes: a right-angle drawable magnetic core coil assembly 5 and a power management module 6 connected to the right-angle drawable magnetic core coil assembly 5 . Among them, the right-angle movable magnetic core coil assembly 5 is clamped to the surface of the cable to be collected, and is set to convert the magnetic energy of the cable to be collected into the output signal of the right-angle movable magnetic core coil assembly 5; the power management module 6 and the sensor load It is connected to convert the output signal of the right-angle twitchable magnetic core coil assembly 5 into a stable power supply voltage, so as to provide the sensor load.

As shown in FIG. 5 , the non-closed right-angle twitch magnetic core coil includes a plurality of thin cylindrical magnetic cores 7 and a magnetic core coil 8 sleeved on the outer side of the thin cylindrical magnetic core 7 . At least a portion of the core 7 is twitchable relative to the core coil. At least a part of the adjacent thin cylindrical magnetic cores 7 are attached together in parallel with each other, and the arrangement direction of the plurality of thin cylindrical magnetic cores 7 is parallel to the extension direction of the cable to be collected, so as to better fit the to-be-collected cable. surface of the cable.

Among them, in order to further improve the power density, the right-angle twitchable magnetic core coil assembly 5 adopts a twitching structure design, that is, a plurality of twitchable thin cylindrical magnetic cores 7 are used, and at least one thin cylindrical magnetic core 7 is used for The relative displacement is relative to the magnetic core coil 8 moving outward for a certain distance to increase the length of the magnetic circuit in the magnetic core, so that a larger magnetic density can be obtained. The specific distance that the thin cylindrical magnetic core 7 moves outward is determined according to the experimental results, so as to achieve the maximum output power.

The thin cylindrical magnetic core 7 is a permalloy with an initial relative magnetic permeability of 50,000, and its cross-sectional area and length can be adjusted according to the size and current-carrying capacity of the object to be measured, such as the cable to be collected.

In this embodiment, the thin cylindrical magnetic core 7 includes a plurality of straight thin cylindrical magnetic cores whose overall shape is a straight line and a plurality of right-angled thin cylindrical magnetic cores whose overall shape is two line segments extending outward from a right-angle vertex magnetic core. The straight-line thin-column core can be twitched, and the number is 8, and the right-angle thin-column core cannot be twitched, and the number is 3. The cross-sectional shapes of the thin cylindrical cores 7 are all circular. For the slender cylindrical magnetic core 7 with a circular cross-sectional shape, after the relative magnetic permeability is determined, the effective magnetic permeability is only related to the ratio of height to diameter. 8 thin cylindrical magnetic cores and 3 right-angle thin cylindrical magnetic cores replace the commonly used right-angle magnetic cores to obtain a magnetic core group with high effective magnetic permeability to improve power density.

The material of the magnetic core coil 8 is pure copper, and the coil diameter and the number of turns can be adjusted according to the requirements of the object to be measured. The core coil 8 has two ports, and both ports of the core coil 8 are connected to the power management module.

A capacitor is connected in series with one port of the magnetic core coil 8, and the capacitor is connected to the power management module 6; or the magnetic core coil 8 is connected in parallel with a capacitor (ie, both ports are connected to the capacitor). The capacitor is matched with the reactance of the coil itself, thereby reducing the power loss of the coil inductance to improve the power acquisition and transmission efficiency. The resonance principle is adopted to eliminate the coil self-inductance, and the output power is improved.

Experimental results

The following takes the environment of 110kV single-core XLPE cable as an example, and designs the inductive power taking device when the cable is energized. The diameter of the cable is 105mm. The main structure of the cable is from inside to outside: copper core, inner semiconductor shielding layer, XLPE insulating layer, outer semiconductor shielding layer, metal sheath, and outer insulating sheath.

Then, the technical solution of the non-closed magnetic core induction power taking device according to the first embodiment of the present invention is:

The thin cylindrical magnetic core 3 is made of permalloy with an initial relative magnetic permeability of 50000. The cross-sectional area of a single thin cylindrical magnetic core 3 is 31 mm ² , and the height of the seven thin cylindrical magnetic cores 3 is the same as that of the original rectangular parallelepiped core. , both are 150mm. The magnetic core coil 4 adopts a copper wire with a wire diameter of 0.5 mm and a number of turns of 3000, the thickness of the coil domain is 5 mm, and the height of the coil domain is 150 mm. The twitching structure twitches the first and seventh thin-column cores 3 of the twitchable magnetic core coil assembly to one side by 70mm, and the fifth thin-column core 3 in the center twitches 70mm to the other side. The overall length of the core is 290mm. The capacitance configured at the magnetic core coil port is 12.37μF when the capacitor is a matched series capacitor; when the capacitor is a matched parallel capacitor, its capacitance is 12.19μF. In the embodiment of the present invention, under the condition that the cable flows through 200A, the output power of the linear twitchable magnetic core coil assembly 1 is 44mW.

The technical solution of the non-closed magnetic core induction power taking device according to the second embodiment of the present invention is:

In the right-angle pullable magnetic core coil assembly 5, the material of the thin cylindrical magnetic core 7 is permalloy with an initial relative magnetic permeability of 50000, the cross-sectional area of the thin cylindrical magnetic core 7 is 31 mm ² , and the eight straight lines The height of the cylindrical core is 75mm, and the sum of the two right-angled sides of the three right-angled thin cylindrical cores is 150mm. The core coil 8 selects a copper wire with a wire diameter of 0.5 mm and a number of turns of 3000, the thickness of the coil domain is 5 mm, and the sum of the right-angled sides on both sides of the coil domain is 150 mm. In the twitching structure, the third and fifth thin cylindrical magnetic cores on both sides of the twitching magnetic core are twitched outward by 50mm, and the overall length of the magnetic core after the twitching is 177mm. The capacitance configured at the magnetic core coil port is 12.37μF when the capacitor is a matched series capacitor; when the capacitor is a matched parallel capacitor, its capacitance is 12.19μF. In the embodiment of the present invention, under the condition that the cable flows through 200A, the output power of the induction power taking module is 50mW.

Therefore, the technical solution of the first embodiment of the present invention uses the linear twitching structure and the resonance principle to improve the output power, and the technical solution of the second embodiment of the present invention uses the right-angle twitching structure and the resonance principle to improve the output power. It is a right-angle twitching structure, and its shape and size are optimized to achieve the best power output effect. The inductive power take-off device of the non-closed magnetic core of the present invention solves the problem that the inductive power take-off device is compatible with different voltage levels and cable diameters by changing the magnetic core from the closed type to the non-closed type. The whole magnetic core is equivalently replaced with several thin magnetic cores with higher effective magnetic permeability. The magnetic core can be twitched to change the length of the magnetic circuit in the magnetic core, so that the output power and power density of the whole magnetic core can be improved, and the non-magnetic core can be improved. The power of the closed magnetic core induction power-taking device has been raised to an applicable level, providing a fast and low-cost online power-taking method for micro-sensors for power, which is conducive to the large-scale deployment and application of power sensors in the field of power monitoring, and is a great tool for micro-sensors. Nano-power sensors provide a new solution for convenient, fast and low-cost inductive power extraction. In addition, the capacitor provided in the non-closed magnetic core of the present invention adopts the resonance principle to eliminate the coil self-inductance and improve the output efficiency.

Claims (10)

1. A non-closed magnetic core inductive power take-off device, characterized in that it comprises a non-closed movable magnetic core coil assembly and a power management module connected to it, wherein the movable magnetic core coil assembly includes a plurality of A thin cylindrical magnetic core and a magnetic core coil sleeved on the outer side of all thin cylindrical magnetic cores, at least a part of the thin cylindrical magnetic core can be twitched relative to the magnetic core coil. 2 . The inductive power take-off device of a non-closed magnetic core according to claim 1 , wherein at least a part of adjacent thin cylindrical magnetic cores are attached to each other in parallel, and a plurality of thin cylindrical magnetic cores are attached together in parallel. 3 . The arrangement direction of the cables is parallel to the extension direction of the cables to be collected. 3 . The inductive power take-off device of a non-closed magnetic core according to claim 1 , wherein the drawable magnetic core coil assembly is a linear drawable magnetic core coil assembly, and the thin cylindrical magnetic core only has 3 . It consists of a straight slender cylindrical core whose overall shape is straight. 4 . The inductive power take-off device of a non-closed magnetic core according to claim 3 , wherein the number of the straight thin cylindrical magnetic cores is seven. 5 . 5 . The inductive power take-off device of a non-closed magnetic core according to claim 1 , wherein the drawable magnetic core coil assembly is a right-angle drawable magnetic core coil assembly, and the thin cylindrical magnetic core comprises: 6 . A plurality of straight slender cylindrical magnetic cores with an overall shape of a straight line and a plurality of right-angled slender cylindrical magnetic cores with an overall shape of two line segments extending outward from a right-angle vertex. 6 . The inductive power take-off device of a non-closed magnetic core according to claim 5 , wherein the number of the straight thin cylindrical magnetic cores is 8, and the number of the right angle thin cylindrical magnetic cores is 3 6 . indivual. 7 . The inductive power take-off device of a non-closed magnetic core according to claim 1 , wherein the cross-sectional shape of the thin cylindrical magnetic core is circular. 8 . 8 . The inductive power taking device of claim 1 , wherein the magnetic core coil has two ports, and the two ports of the magnetic core coil are both connected to the power management module; 8 . A capacitor is connected in series with one port of the magnetic core coil, and the capacitor is connected to the power management module, or the magnetic core coil is connected in parallel with a capacitor. 9 . The inductive power taking device of claim 1 , wherein the material of the magnetic core coil is pure copper. 10 . 10 . The inductive power take-off device of a non-closed magnetic core according to claim 1 , wherein the material of the thin cylindrical magnetic core is permalloy with an initial relative magnetic permeability of 50,000. 11 .

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