公开(公告)号：US20220373621A1

公开(公告)日：2022-11-24

申请号：US17609703

申请日：2021-01-22

Applicant: SOUTHEAST UNIVERSITY

Inventor： Ming CHENG ,  Zheng WANG ,  Xinkai ZHU ,  Wei QIN

IPC: G01R33/12 ,  G01R21/133

Abstract: Disclosed is a power calculation method of a magnetic circuit. In view of the power problem of a magnetic circuit and the phase problem of a magnetomotive force (MMF) and a magnetic flux in the magnetic circuit, the present disclosure draws a magnetic circuit vector diagram based on an equivalent magnetic circuit vector model, and provides a method for calculating virtual magnetic active power, virtual magnetic reactive power, and virtual magnetic complex power of the magnetic circuit by analyzing the MMF, the magnetic flux, the reluctance, and the magnetic reactance in the magnetic circuit by using the magnetic circuit vector diagram. A mathematical relationship between the virtual magnetic power of the magnetic circuit and the electric power of the corresponding equivalent electric circuit is derived according to a conversion factor between the virtual magnetic power and the electric power, so that the electric power can be directly calculated according to magnetic parameters such as the MMF and the magnetic flux in the magnetic circuit. The power calculation method of the magnetic circuit provided in the present disclosure can calculate and analyze the virtual magnetic power of the magnetic circuit according to the magnetic circuit vectors, so as to calculate the electric power from the magnetic circuit through conversion. The electric power can be solved according to the magnetic circuit vectors directly when the electric vectors are not available to calculate electric power in electromagnetic components.

公开(公告)号：US20240395454A1

公开(公告)日：2024-11-28

申请号：US18261957

申请日：2023-02-14

Applicant: Southeast University

Inventor： Ming CHENG ,  Wei QIN ,  Xinkai ZHU ,  Wei HUA ,  Zheng WANG ,  Sa ZHU ,  Zhiyuan XU

IPC: H01F27/34 ,  H01F27/24

Abstract: According to a magnetic core considering the skin effect of magnetic flux and a design method thereof, with a cross-section of a magnetic core through which magnetic flux flows as a reference surface, the shape of the cross-section of the magnetic core is designed according to the electromagnetic characteristics, temperature characteristics, magnetic flux amplitude and operating frequency of the magnetic core, and a closed or discontinuous air path is formed inside the magnetic core by stretching the reference surface along the path of the magnetic flux, thereby forming a magnetic core having a duct structure. When a high-frequency magnetic flux is introduced into the magnetic core, the magnetic core considering the skin effect of magnetic flux and the design method thereof can reduce the weight of the magnetic core, reduce the power loss and temperature rise of the magnetic core, and suppress the skin effect of the magnetic core.

公开(公告)号：US20220366106A1

公开(公告)日：2022-11-17

申请号：US17612942

申请日：2021-01-22

Applicant: SOUTHEAST UNIVERSITY

Inventor： Ming CHENG ,  Zheng WANG ,  Wei QIN ,  Xinkai ZHU

IPC: G06F30/23 ,  H01F41/02

Abstract: The present invention discloses a calculation method of eddy current loss in magnetic materials based on magnetic-inductance. The present invention proposes a vector model of a magnetic circuit, an eddy current reaction is equivalent to a magnetic-inductance component in the magnetic circuit, and the eddy current loss can be fast calculated by the vector model of the magnetic circuit. When the frequency is high, the eddy current loss dominates an iron loss and can be estimated as an entire iron loss. The present invention proposes the vector model of the magnetic circuit based on which the calculation method of eddy current loss in magnetic materials is proposed as well. Through the proposed method the eddy current loss in magnetic materials can be directly calculated by using the magnetic-inductance and the magnetic flux in the magnetic circuit, which can provide guidance for design and performance evaluation of high-frequency electrical equipment from a brand new viewpoint.

公开(公告)号：US20220342014A1

公开(公告)日：2022-10-27

申请号：US17613847

申请日：2021-01-22

Applicant: SOUTHEAST UNIVERSITY

Inventor： Ming CHENG ,  Xinkai ZHU ,  Wei QIN ,  Zheng WANG

IPC: G01R33/12

Abstract: The present invention discloses a measurement method for a B-H curve of magnetic material based on a magnetic-inductance principle, and relates to the field of electric engineering. A measurement apparatus includes an Epstein frame, an alternating power supply, a power analyzer, and an oscilloscope. The core content of the present invention is to perform electromagnetic coupling modeling on an Epstein frame based on a vector model of a magnetic circuit, where an iron core of the Epstein frame is formed by laminating a silicon steel sheet to be measured, and an excitation coil and a detection coil with the same turns number are wound around the iron core. The measurement process is to first obtain a reference B-H curve that only considers a nonlinear reluctance of the iron core, and then to derive a B-H curve considering an eddy current effect in a magnetic field at any frequency from the reference B-H curve. The present invention provides a measurement and simulation method for deriving a B-H curve at any frequency by only measuring a B-H curve at a certain frequency. The method, applicable to a measurement for B-H curves at middle and high frequencies, may obtain much higher accuracy.

公开(公告)号：US20250157726A1

公开(公告)日：2025-05-15

申请号：US19021098

申请日：2025-01-14

Applicant: SOUTHEAST UNIVERSITY

Inventor： Ming CHENG ,  Wei QIN ,  Chengbo LI ,  Zheng WANG ,  Wei HUA ,  Xinkai ZHU

IPC: H01F27/34 ,  G01R33/14 ,  H01F41/04

Abstract: The present disclosure relates to a hysteretance component, which is designed based on its definition, calculation formulas, and port characteristics. By increasing or decreasing hysteretance components in a magnetic circuit, the intensity and effect magnitude of magnetic hysteresis in a vector magnetic circuit can be estimated and controlled from the perspective of magnetic circuit, allowing the vector state of a magnetic flux to be consistent with the desired state. Based on this, an application method is proposed, involving that a target magnetic circuit is formed by connecting reluctance, magductance, and hysteretance components in series, and magnetic circuit parameters of the three components are utilized to quantitatively express magnetization, eddy current, and magnetic hysteresis phenomena, enabling technicians to selectively alter the operating characteristics of the magnetic circuit, vector magnetic quantities, and power of the magnetic circuit by adjusting the parameters.

公开(公告)号：US20220399158A1

公开(公告)日：2022-12-15

申请号：US17608934

申请日：2021-01-22

Applicant: SOUTHEAST UNIVERSITY

Inventor： Ming CHENG ,  Wei QIN ,  Zheng WANG ,  Xinkai ZHU

IPC: H01F27/30

Abstract: The present invention provides a magnetic-inductance component, and relates to the field of magnetic circuit theory and application, and in particular, to the design of magnetic circuit components. The magnetic-inductance component is a multi-turn short-circuit coil wound around a magnetic circuit. A magnetic-inductance value of the magnetic-inductance component is adjusted by selecting metal conductors with different numbers of turns, materials, cross-sectional areas, and lengths to change an amplitude and a phase of a magnetic flux of the magnetic circuit. The present invention purposely changes the operating state and operating trajectory of a vector in the magnetic circuit by adding the magnetic-inductance component to the magnetic circuit or removing the magnetic-inductance component from the magnetic circuit, to make a state of a magnetic flux vector in the magnetic circuit to be consistent with a target magnetic flux vector state. Compared with a magnetic circuit including a reluctance only, a magnetic circuit vector model built by using the magnetic-inductance component as a core is more consistent with the actual physical situation, which is beneficial to the improvement of the accuracy of magnetic circuit analysis and calculation.

公开(公告)号：US20240030838A1

公开(公告)日：2024-01-25

申请号：US18249533

申请日：2022-07-27

Applicant: SOUTHEAST UNIVERSITY

Inventor： Ming CHENG ,  Wei QIN ,  Xinkai ZHU ,  Zheng WANG ,  Wei HUA

IPC: H02N11/00

CPC classification number: H02N11/002

Abstract: A power generation device and method based on the time-varying magductance principle relate to the field of energy conversion, and in particular relate to an electromagnetic induction power generation device. The power generation device includes an electric energy generation unit, a power conversion unit and an electric energy storage unit. The electric energy generation unit includes a time-varying magductance component configured to form a closed conductor loop in a magnetic circuit with constant magnetic flux. By changing a magductance parameter of the time-varying magductance component, the time-varying magductance component generates induced current. The power conversion unit consists of a switching device and a circuit. The electric energy generated by the time-varying magductance component can be stored into the electric energy storage unit through controlling the switching device. The time-varying magductance power generation device provided by the present invention provides a new way for electric energy generation.