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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.
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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
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.
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公开(公告)号：US20240178768A1
公开(公告)日：2024-05-30
申请号：US18550652
申请日：2023-04-12
Applicant: SOUTHEAST UNIVERSITY
Inventor： Wei WANG , Weijie TIAN , Ming CHENG
CPC classification number: H02P5/48 , H02P21/141 , H02P21/22 , H02P27/06
Abstract: A control method for a semi-centralized open winding multi-motor drive system includes: first, measuring current, voltage and position signal, computing system thrust by a velocity loop; then, distributing the thrust to each motor, converting the thrust into q axis current, computing dq axis voltages required for each motor by a current loop, and transforming the voltage demand to abc coordinate system through coordinate transformation; subsequently, modulating the voltage of each motor into a duty ratio instruction to judge whether the motor is in an over-modulated operating area, and performing over-modulation processing on the voltage in the over-modulated area; and finally, distributing the duty ratio instructions to independent and shared inverters. The control method of the present disclosure can reduce the hardware cost and improve the safety and reliability of the system.
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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.
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5.发明申请公开(公告)号：US20200220361A1
公开(公告)日：2020-07-09
申请号：US16627363
申请日：2018-10-17
Applicant: SOUTHEAST UNIVERSITY
Inventor： Huafeng XIAO , Zheng WANG , Ming CHENG
Abstract: A grid access current control method without current sensor applicable to a grid-connected inverter relates to a system including a main circuit of the grid-connected inverter and a control circuit of the grid-connected inverter. The control circuit of the grid-connected inverter includes a grid access current open-loop control module and a PWM generation module; the grid access current open-loop control module includes a first proportional regulator, a second proportional regulator, a delayer, and an adder; input ends of the first proportional regulator and the second proportional regulator each are led out as an input end of a grid access current reference signal; and an output end of the first proportional regulator is connected to an input end of the adder; an output end of the second proportional regulator is connected to an input end of the delayer.
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Patent Agency Ranking
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.
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公开(公告)号：US20190114385A1
公开(公告)日：2019-04-18
申请号：US15758854
申请日：2017-02-20
Applicant: SOUTHEAST UNIVERSITY
Inventor： Ming CHENG , Sa ZHU
IPC: G06F17/50
Abstract: A motor thermal analysis method with a temperature field directly coupled with a thermal circuit is used for modeling partial parts of the motor, and a thermal circuit method is used for modeling other parts. A temperature field is contacted with a thermal circuit through an equivalent temperature boundary and an equivalent convection boundary. The thermal circuit part is composed of one-dimensional finite elements, and two connecting boundaries are deemed as two boundary elements. An element stiffness matrix, an element loading matrix and an element mass matrix corresponding to the one-dimensional finite elements and the boundary elements are respectively overlaid to a global stiffness matrix, a global loading matrix and a global mass matrix, and the distribution of temperature in the temperature field and the distribution of temperature in the thermal circuit are obtained simultaneously by solving a whole system of linear equations.
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8.发明申请公开(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
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.
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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.
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公开(公告)号：US20210359587A1
公开(公告)日：2021-11-18
申请号：US16979536
申请日：2020-02-27
Applicant: SOUTHEAST UNIVERSITY
Inventor： Wei HUA , Peixin WANG , Gan ZHANG , Baoan WANG , Ming CHENG
Abstract: A coaxial double-rotor variable-speed electromagnetic drive includes an external rotor, an end cover, a load shaft, a stator, and an internal rotor, the external rotor, the load shaft, the stator, and the internal rotor being coaxially arranged. The end cover includes a first end cover and a second end cover that are respectively disposed at two ends of the drive, the external rotor is slidably connected to the two end covers separately by bearings, the load shaft is slidably connected to the first end cover and the inner side of the external rotor separately by bearings, the stator is fixed on the inner side of the first end cover and disposed inside the external rotor, air gaps are kept separately between the stator and the internal rotor and between the stator and the external rotor, the internal rotor is sleeved on the load shaft and is disposed inside the stator.
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