A magnetic field coil having a gradient compensation winding

Abstract

The utility model discloses a kind of magnetic field coils with gradient compensation winding, including main coil, main coil includes X direction main coil, Y direction main coil and Z direction main coil, each main coil side is separately provided with gradient compensation winding, gradient compensation winding is independently controlled sub-coil additionally provided in main coil inside or outside, the utility model passes through additional gradient compensation winding generates opposite magnetic field with environmental magnetic field gradient, so that target area net magnetic field uniformity reaches within ±0.05%;Gradient compensation winding and main coil integrated design, do not extra occupy space;Combining sensor feedback real-time adjustment compensation current, adapt to changing environmental magnetic field;It is applicable to the large-scale coil of diameter>1m, satisfy aerospace, biomagnetism, space optics and other large sample experiment needs.

Description

Technical Field

[0001] This utility model relates to the field of large magnetic field coil technology, specifically a magnetic field coil with gradient compensation winding. Background Technology

[0002] Currently, large magnetic field coils face the following problems in scientific research and industrial applications:

[0003] 1. Environmental magnetic field interference: The gradient of the environmental magnetic field, such as the Earth's magnetic field and the magnetic field of nearby equipment, will be superimposed on the coil's magnetic field, causing the magnetic field uniformity of the target area to decrease (e.g., from ±0.1% to ±1%).

[0004] 2. Limitations of passive shielding: Traditional magnetic shielding (such as soft magnetic alloy shields) can only weaken high-frequency or constant environmental fields and cannot compensate for spatial gradients;

[0005] 3. Lack of dynamic compensation: Existing active compensation technologies are mostly aimed at overall magnetic field offset (such as canceling geomagnetism through reverse coils), but cannot correct spatial inhomogeneity;

[0006] 4. Difficulty in adapting large coils: The compensation system is usually independent of the main coil, with a complex structure and occupying experimental space. Utility Model Content

[0007] The purpose of this invention is to provide a magnetic field coil with gradient compensation windings to solve the problems mentioned in the background art, such as environmental magnetic field interference, passive shielding limitations, lack of dynamic compensation, and difficulty in adapting large coils in scientific research and industrial applications.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a magnetic field coil with gradient compensation windings, including a main coil, which includes an X-direction main coil, a Y-direction main coil and a Z-direction main coil. Each main coil has a gradient compensation winding on its side, and the gradient compensation winding is an independently controlled sub-coil added inside or outside the main coil.

[0009] The gradient compensation winding is made of thin-layer PCB or ribbon cable.

[0010] A high-precision triaxial fluxgate meter is installed inside the main coil.

[0011] A high-precision triaxial fluxgate meter is fixed on the test frame.

[0012] The main coil and gradient compensation winding are wound in fiberglass channel profiles in three directions.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. Active gradient compensation of this utility model: By adding a gradient compensation winding, a magnetic field opposite to the gradient of the ambient magnetic field is generated, so that the net magnetic field uniformity of the target area reaches within ±0.05%.

[0015] 2. This utility model adopts an integrated structure: the gradient compensation winding and the main coil are integrated into one design, without occupying additional space;

[0016] 3. The dynamic adjustment capability of this utility model: Combined with sensor feedback, the compensation current is adjusted in real time to adapt to changing environmental magnetic fields;

[0017] 4. Compatibility of this utility model: It is applicable to large coils with a diameter >1m, meeting the needs of large-sample experiments in aerospace, biomagnetism, space optics and other fields. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0019] Figure 2 This is a front view of the present utility model;

[0020] Figure 3 for Figure 2 A cross-sectional view along the AA direction;

[0021] Figure 4 for Figure 3 Enlarged view of a section at point B in the middle;

[0022] Figure 5 This is a schematic diagram of the installation structure of the main coil and gradient compensation winding in this utility model.

[0023] In the above attached diagram, the main coil is 1, the gradient compensation winding is 2, the high-precision triaxial fluxgate magnetometer is 3, the test frame is 4, the fiberglass channel profile is 5, the connector is 6, and the protective cover is 7. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0025] like Figure 1-5As shown, this utility model provides a magnetic field coil with a gradient compensation winding 2. The magnetic field coil includes a main coil 1 and a gradient compensation winding 2 attached to the side of the main coil 1. The main coil 1 includes an X-direction main coil, a Y-direction main coil, and a Z-direction main coil, and adopts a traditional uniform coil structure to provide a basic uniform magnetic field. In this embodiment, the main coil 1 generates magnetic fields in three directions: X, Y, and Z. Each main coil 1 has a gradient compensation winding 2 on its side. The gradient compensation winding 2 is an independently controlled sub-coil added inside or outside the main coil 1. The gradient compensation winding 2 generates a magnetic field that is opposite to the gradient of the ambient magnetic field, so that the net magnetic field uniformity of the target area reaches within ±0.05%. The gradient compensation winding 2 is wound with a thin-layer PCB or ribbon cable to reduce interference with the magnetic field of the main coil 1.

[0026] A high-precision triaxial fluxgate meter 3 is installed inside the main coil 1. According to the actual size requirements, an epoxy board is used to build a test frame 4, and multiple triaxial fluxgate meters are fixed on the test frame 4 to detect the magnetic field value at each point in real time. Multiple sets of high-precision triaxial fluxgate meters 3 form a fluxgate array. High-precision triaxial fluxgate meters 3 are arranged in the target area to monitor the magnetic field gradient in real time.

[0027] In this invention, the main coil 1 and the gradient compensation winding 2 are respectively wound within fiberglass channel profiles 5 in three directions. Each fiberglass channel profile forms a coil skeleton, and the fiberglass channel profiles are connected by connectors 6 to form a rectangular overall coil skeleton. The overall coil skeleton is made of a non-magnetic composite material (such as GFRP) to avoid introducing additional gradients. Even in the presence of environmental gradients, the magnetic field uniformity in the target area can still be maintained at ≤±0.05% (e.g., within 10cm DSV). A protective cover 7 is provided outside the fiberglass channel profile to protect the main coil 1 and the gradient compensation winding 2.

[0028] This invention features real-time adaptability: its dynamic compensation capability can cope with sudden magnetic field changes such as laboratory door opening and closing, equipment start-up and shutdown; space efficiency: its integrated design eliminates the need for external compensation devices, preserving a large sample cavity space; low power consumption: the compensation winding only needs to offset the environmental gradient, with power consumption less than 5% of the main coil 1; and applicability to multiple scenarios: it is compatible with steady-state magnetic field and pulsed magnetic field modes.

[0029] This utility model connects to an external sensing and control system:

[0030] The sensing and control system receives real-time magnetic field gradient data from a high-precision triaxial fluxgate magnetometer 3; the feedback algorithm dynamically adjusts the current in the gradient compensation winding 2 through PID control or a machine learning model to bring the gradient close to zero. Specifically, it includes the following steps:

[0031] Step 1: System initialization, start the magnetometer array, and measure the ambient magnetic field gradient when no power is applied.

[0032] Step 2: Excite the main coil 1 and apply the main current to generate a basic uniform magnetic field. At this time, the measured uniformity after superimposing the environmental gradient is ±0.8%.

[0033] Step 3: Gradient compensation, the control system calculates the required compensation current; after compensation, the magnetometer feedback shows that the gradient residual is ≤0.1μT / m, and the uniformity is improved to ±0.03%.

[0034] Step 4: Dynamic maintenance, updating compensation parameters every 0.5 seconds to cope with fluctuations in the environmental magnetic field.

Claims

1. A magnetic field coil with gradient-compensated windings, characterized in that, It includes a main coil, which includes an X-direction main coil, a Y-direction main coil, and a Z-direction main coil. Each main coil has a gradient compensation winding on its side. The gradient compensation winding is an independently controlled sub-coil added inside or outside the main coil.

2. A magnetic field coil with gradient compensation winding according to claim 1, characterized in that, The gradient compensation winding is made of thin-layer PCB or ribbon cable.

3. A magnetic field coil with gradient compensation winding according to claim 1, characterized in that, A high-precision triaxial fluxgate meter is installed inside the main coil.

4. A magnetic field coil with gradient compensation winding according to claim 3, characterized in that, A high-precision triaxial fluxgate meter is fixed on the test frame.

5. A magnetic field coil with gradient compensation winding according to claim 1, characterized in that, The main coil and gradient compensation winding are wound in fiberglass channel profiles in three directions.

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