High-power switching power supply device applied to static magnetic field

Abstract

The invention discloses a high-power switching power supply device applied to a static magnetic field. The device adopts a four-stage protection system, wherein the first stage is a double-nested structure shell formed by attaching a pure iron plate and permalloy through conductive silicone grease, and overall efficient magnetic shielding is achieved; the second stage is a local reinforced shielding chamber which is internally made of a pure iron plate and is used for carrying out secondary isolation on the control and power module; the third stage adopts at least two LLC power modules which are connected in parallel and are symmetrically arranged, and the static magnetic field influence is inhibited from the source through magnetic field offset; and the fourth stage carries out fine management on the opening and the gap through a magnetic shielding waveguide tube and a magnetic conductive sealing strip. The control system adopts an optical fiber and a shunt for sampling, and CAN communication and current sharing control are combined, so that the signal accuracy and the system stability are ensured. The problems of loss increase, control instability and the like caused by magnetic saturation of a high-power switching power supply in a static magnetic field environment are solved, and high-reliability and high-power direct-current conversion output in a strong static magnetic field environment is realized.

Description

Technical Field

[0001] This invention relates to the field of energy system technology, and in particular to a high-power switching power supply device that can operate stably and reliably in a strong static magnetic field environment. Background Technology

[0002] Traditional switching power supplies face severe challenges in static magnetic field environments such as those used in MRI (Magnetic Resonance Imaging) and research with strong magnets. Static magnetic fields can cause saturation or operating point shifts in the magnetic cores of internal power supply components (such as transformers and inductors), leading to a sharp increase in power supply losses, distorted sampling signals, unstable feedback control, and even equipment damage ("explosion"). While existing technologies have attempted to suppress core saturation through frequency control, their effectiveness is limited for high-power applications, and a comprehensive solution encompassing structural design and system control is lacking, making it difficult to guarantee long-term reliable operation of the power supply in strong static magnetic field environments. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-power switching power supply device for use in static magnetic fields. Through comprehensive source suppression, multi-level shielding and fine management, the reliable operation problem in static magnetic field environment is solved.

[0004] The technical solution adopted in this invention is a high-power switching power supply device applied to static magnetic fields. The double-nested structure housing is constructed by tightly bonding an outer layer of pure iron plate and an inner layer of high-permeability 1J85 permalloy with conductive silicone grease having a resistivity not exceeding 1 Ω·cm, used for static magnetic field shielding and isolation of the entire device. A locally reinforced shielding metal housing, made of pure iron plate, is disposed within the double-nested structure housing, forming independent shielding chambers for the control module and power module respectively. The symmetrical parallel power module consists of at least two power units using an LLC topology connected in parallel. The power units are symmetrically arranged so that the magnetic fields they generate have opposite polarities, thus canceling the influence of the external static magnetic field from the source. The control module is disposed within the locally reinforced shielding metal housing, used to collect voltage and current signals, and manage the operating state and current sharing of the symmetrical parallel power modules through control drive signals. The opening and gap management module includes magnetically shielded waveguides with a length-to-diameter ratio of 5:1 installed at the device's ventilation holes and cable holes, and magnetically conductive sealing strips filling the shell seams.

[0005] Preferably, the control module includes a CAN communication module, a current sharing adjustment circuit, and an execution circuit, and uses a shunt and optical fiber for the acquisition and transmission of voltage and current signals.

[0006] Preferably, the opening direction of the magnetically shielded waveguide is arranged parallel to the direction of the magnetic field lines of the external static magnetic field.

[0007] Preferably, the magnetic components within the power unit are arranged in a distributed manner and are located away from the wall panels of the double-nested structure housing. The beneficial effects of this invention are: High reliability: Through a "four-level protection" system, it comprehensively resists static magnetic field interference, ensuring stable operation of the power supply in extreme magnetic environments. High power output: Multi-module parallel current sharing technology easily achieves power expansion, meeting the needs of high-power applications. High cost-effectiveness: The double-nested shell structure cleverly combines the magnetic property advantages of two materials, controlling costs while ensuring performance. Intelligent control: Employing fiber optic sampling and digital current sharing control, it boasts high precision, strong anti-interference capabilities, and good system adaptability. Attached Figure Description

[0008] Figure 1 This is a structural block diagram of the high-power switching power supply device described in this invention.

[0009] Figure 2 This is a schematic block diagram of the high-power switching power supply control system described in this invention.

[0010] Figure 3 This is a cross-sectional schematic diagram of the double-nested structure housing of the high-power switching power supply control system described in this invention.

[0011] The markings in the diagram are: 1-Pure iron sheet metal, 2-Conductive silicone grease, 3-Permalloy. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0013] See Figure 1The device of this invention mainly includes: a double-nested structure shell, a locally reinforced shielded metal shell, symmetrical parallel power modules, a control module, and an opening and gap management module. The double-nested structure shell is the outer shell of the device, with an outer layer of pure iron sheet metal and an inner layer of permalloy 3, filled with conductive silicone grease 2 between the layers to form a continuous low magnetic reluctance shield. The locally reinforced shielded metal shell is made of pure iron plate and has separate chambers inside the shell to house the control module and the symmetrical parallel power modules, providing secondary shielding for the sensitive components within. The symmetrical parallel power modules consist of power module one and power module two. Each power module adopts an LLC resonant topology, with its internal transformers and inductors arranged away from the shell walls in a distributed manner. The two power modules are physically symmetrical or mirror-symmetrical, allowing their magnetic fields to cancel each other out during operation. The control module is located in its independent shielded chamber and its core components include a main control chip, a CAN communication interface, a current sharing control circuit, and a drive circuit. It collects load current through a shunt and output voltage through fiber optic isolation. These signals are processed by the main control chip to generate PWM drive signals, controlling the operation of the power module and achieving precise current sharing. The opening and gap management module installs multiple magnetically shielded waveguides at the ventilation openings of the chassis, with their long axis parallel to the direction of the external static magnetic field. All joints between the chassis covers and modules are fitted with magnetic sealing strips.

[0014] like Figure 2 As shown, the control system's workflow is as follows: After the system powers on, the control module acquires the output voltage Vo and output current Io in real time via optical fiber and a shunt. The acquired signals are filtered, amplified, and then compared with a reference signal after tuning calculations. Based on the comparison result and the current sharing algorithm, the main control chip generates a corresponding PWM drive signal. This signal controls the switching transistors in the symmetrical parallel power modules through the drive circuit, achieving stable voltage conversion and power output. Simultaneously, the control module communicates with the host computer or other devices via the CAN bus, reporting operating status, fault information, etc. This closed-loop control system continuously maintains stable operation of the power supply in a 20mT static magnetic field environment.

[0015] The key technical points of this invention are as follows: 1. A high-power switching power supply device and control system for use in static magnetic fields. This device achieves reliable DC voltage output in static magnetic field environments through source suppression, shielding isolation, and auxiliary management using openings and gaps.

[0016] 2. The device comprises a high-power switching power supply and control system for static magnetic fields, consisting of a double-nested shell, a locally reinforced shielded metal shell, an opening and gap management module, a symmetrical parallel power module, and a control module.

[0017] 3. The double-nested shell is made of pure iron plate, permalloy and conductive silicone grease. The double-nested shell combines the advantages of the two materials to achieve a more efficient and economical shell shielding and isolation effect.

[0018] 4. The locally reinforced shielded metal shell is constructed of pure iron plate to create an isolation chamber for locally reinforced shielding of components in the control module and power module that are susceptible to static magnetic field interference, thereby achieving a secondary shielding and isolation effect for the sampling devices in the control module and the magnetic components in the power module.

[0019] 5. The opening and gap management module is composed of a magnetically shielded waveguide and a magnetically conductive sealing strip. By refining the management of openings and gaps, the static magnetic field shielding effect is improved, ensuring the reliable operation of the device.

[0020] 6. The symmetrical parallel power module adopts two LLC topology power modules symmetrically arranged, so that the polarities of adjacent magnetic fields are opposite, which cancels out part of the external magnetic field and suppresses the influence of static magnetic field on the saturation deviation of magnetic core of magnetic components from the source.

[0021] 7. The control module uses a CAN communication module to implement communication functions to complete the acquisition and reporting of electrical signals. The current sharing adjustment circuit and the execution circuit perform action adjustment. The voltage and current acquisition is carried out by a shunt and optical fiber transmission to avoid the distortion of the sampling signal. This realizes the voltage regulation control output of a high-power switching power supply device and control system applied to static magnetic fields.

[0022] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A high-power switching power supply device applied to a static magnetic field, characterized by, The double-nested structure shell is formed by tightly adhering the outer layer of pure iron plate and the inner layer of high permeability 1J85 permalloy through conductive silicon grease with resistivity not higher than 1 Ω·cm, and is used for magnetically shielding and isolating the whole device; the locally reinforced shielding metal shell is arranged in the double-nested structure shell and is made of pure iron plate, and is used for forming independent shielding chambers for the control module and the power module respectively; the symmetric parallel power module is formed by at least two power units adopting LLC topology structure in parallel, the power units are symmetrically arranged so that the generated magnetic fields are opposite in polarity to cancel the influence of external static magnetic field from the source; the control module is arranged in the locally reinforced shielding metal shell, and is used for collecting voltage and current signals and managing the working state and current sharing of the symmetric parallel power module through control driving signals; The opening and gap management module comprises magnetic shielding waveguides with a length-diameter ratio of 5:1 installed at the ventilation holes and cable holes of the device, and magnetic conductive sealing strips filled at the joints of the shell.

2. A high-power switching power supply device for application to a static magnetic field according to claim 1, characterized in that, The control module comprises a CAN communication module, a current sharing adjustment circuit and an execution circuit, and adopts a shunt and an optical fiber to collect and transmit voltage and current signals.

3. A high-power switching power supply device for application to a static magnetic field according to claim 1, characterized in that, The opening direction of the magnetic shielding waveguide is arranged parallel to the magnetic line direction of the external static magnetic field.

4. A high-power switching power supply device for application to a static magnetic field according to claim 1, characterized in that, The magnetic components in the power unit are arranged in a distributed manner and are away from the wall plate of the double-nested structure shell.

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