Patent Summary for CN110770860B: Reactor core and its reactor
I. Abstract and Technical Field
The invention provides a reactor magnetic core and a reactor that are designed to improve the utilization rate of the yoke iron, achieve a compact structure, and simplify manufacturing, particularly for high-frequency applications like photovoltaic inverters and electric vehicle boost circuits.
Key Structure: A hybrid magnetic core design using materials with different saturation flux densities and permeability.
Center Pillar (1): High saturation magnetic flux density material (e.g., metal powder core like Sendust or iron silicon aluminum).
Upper Yoke (2) and Lower Yoke (3): Lower saturation magnetic flux density material (e.g., ferrite).
High-Permeability Side Posts (4): At least two side posts with high permeability (e.g., ferrite or amorphous material, with permeability ≥200).
Arrangement:
The Center Pillar (1) is arranged between the middle areas of the upper and lower yokes (2, 3), with a coil (5) wound around it.
The High-Permeability Side Posts (4) are arranged at intervals between the outer edges of the upper and lower yokes (2, 3).
Benefit: The material design and multi-path magnetic circuit structure prevent the yoke from saturating prematurely, effectively utilizing the yoke space, dispersing magnetic flux, and allowing for a reduction in yoke thickness.
II. Background and Description of the Invention
A. Technical Problems of Prior Art
Conventional high-frequency reactors, often replacing traditional silicon steel sheet reactors, face several challenges:
Annular Reactors: Difficult winding and challenging for large-scale production.
Stacked Metal Powder Core Reactors (E-core style): While better than annular, prior art solutions still have limitations:
Magnetic Resin Package: Low permeability of the magnetic resin limits the improvement of yoke utilization rate.
Hybrid Material Designs: While compact and efficient, they often have manufacturing problems, especially for larger dimensions.
Ferrite Slab Core/Hybrid Magnetic Circuit: Difficult to make the ferrite slab core thin and carries the risk of early saturation in the ferrite material.
B. Solution and Configuration
The invention solves the problems of the prior art by using a hybrid core structure and material selection to manage magnetic flux distribution and saturation.
Detailed Configuration:
Core Material Selection:
The Center Pillar (1) material is chosen to have a saturation magnetic flux density (B1) greater than that of the Upper Yoke (2) and Lower Yoke (3) material (B2).
Preferred materials: Center Pillar: Metal powder core (Sendust or iron silicon aluminum); Yokes: Ferrite.
The High-Permeability Side Posts (4) have a permeability of ≥200 and are preferably made of ferrite or amorphous material.
Structure and Assembly:
The Center Pillar (1) has the coil (5) wound on its exterior. An air gap may be provided on the center pillar (1).
Yoke Connection: The center pillar (1) can be inserted into the upper and lower yokes or even penetrate them.
Insertion Depth Requirement: If inserted, the ratio of the insertion depth (D) to the yoke thickness (D′), D′D, is stipulated to be greater than or equal to B1B1−B2 to prevent the yoke's ferrite material from saturating prematurely.
Side Posts: At least two High-Permeability Side Posts (4) are placed between the outer edges of the yokes, preferably symmetrically distributed around the center pillar. These side posts create multiple magnetic flux loops to effectively disperse the magnetic flux.
Reactor Assembly: The complete reactor includes the coil (5) wound outside the center pillar (1).
Insulation: Insulating end rings are provided at the top and bottom of the coil to isolate it from the center pillar and the yokes.
Optional Casing: A case can be placed outside the core, which may be filled with glue to integrally connect all parts.
C. Beneficial Effects
Improved Yoke Utilization: The use of high-saturation material for the center pillar and the insertion into the yokes prevents early saturation of the yoke ferrite, allowing the yoke space to be effectively utilized.
Compact Structure and Easy Manufacturing: The use of at least two high-permeability side columns forms multiple magnetic flux loops, dispersing the magnetic flux. This allows the thickness of the yoke part to be reduced, leading to a compact and easily manufactured structure.
Prevents Early Saturation: The insertion depth design ensures that the yoke material is protected from premature saturation.
III. Main Claims
Claim 1: A reactor magnetic core, comprising a center pillar (1), an upper yoke (2), a lower yoke (3), and at least two high-permeability side posts (4), characterized in that:
The center pillar (1) is arranged between the middle area of the upper yoke (2) and the middle area of the lower yoke (3).
The saturation magnetic flux density of the center pillar (1) is larger than that of the upper yoke (2) and the lower yoke (3).
The high-permeability side columns (4) are arranged between the upper yoke (2) and the lower yoke (3) at intervals, with their two ends connected to the outer edges of the upper yoke (2) and the lower yoke (3) respectively.
Claim 2: The reactor magnetic core of claim 1, where both ends of the center pillar (1) are inserted into the upper yoke (2) and the lower yoke (3), respectively, and a ratio of insertion depth D of each end to the yoke thickness D′, D′D, satisfies the condition: D′D≥B1B1−B2, where B1 is the saturation magnetic flux density of the center pillar (1), and B2 is the saturation magnetic flux density of the upper yoke (2) and the lower yoke (3).
Claim 6: The reactor magnetic core of claim 1, where the center pillar (1) is made of a metal powder core, and the upper yoke (2) and the lower yoke (3) are made of ferrite.
Claim 9: A reactor, comprising a coil (5) and the reactor magnetic core as described in any one of the preceding claims, wherein the coil (5) is wound outside the center pillar (1).
