公开(公告)号：US12255004B2

公开(公告)日：2025-03-18

申请号：US17199953

申请日：2021-03-12

Applicant: VIRGINIA TECH INTELLECTUAL PROPERTIES, INC.

Inventor： Feiyang Zhu ,  Qiang Li ,  Fred C. Lee

IPC: H01F27/28 ,  H01F27/24 ,  H01F27/40 ,  H01F27/42

Abstract: Aspects of multi-phase integrated coupled inductors are described. In one embodiment, a multi-phase integrated coupled inductor includes a magnetic core and a coupled set of inductors. Each inductor can include conductive vias that are asymmetrically distributed in two symmetrical core slots in the magnetic core, so that each inductor has a different number of lateral-flux vias in each slot.

公开(公告)号：US20250055365A1

公开(公告)日：2025-02-13

申请号：US18446888

申请日：2023-08-09

Applicant: VIRGINIA TECH INTELLECTUAL PROPERTIES, INC.

Inventor： Feiyang Zhu ,  Qiang Li ,  Fred C. Lee

IPC: H02M1/00 ,  H01F27/30 ,  H01F27/38 ,  H02M3/158

Abstract: Power converters with integrated controllable coupling inductors are described. An example power converter includes a number of converter stages and an integrated coupled inductor. The integrated coupled inductor includes a magnetic core having a first side leg, a first leg, a center leg, a second leg, and a second side leg. The integrated coupled inductor also includes a first and second windings for first and second converter stage among the converter stages. The first winding extends around the first leg, and the second winding extends around the second leg of the magnetic core. The integrated coupled inductor can also include a second magnetic core with third and fourth windings for additional converter stages and a coupling winding extending around center legs of the magnetic core and the second magnetic core. The integrated coupled inductor does not include a coupling inductor separate from the magnetic core and the second magnetic core.

公开(公告)号：US11848140B2

公开(公告)日：2023-12-19

申请号：US16899053

申请日：2020-06-11

Applicant: Virginia Tech Intellectual Properties, Inc.

Inventor： Mohamed Hassan Abouelella Ahmed ,  Fred C. Lee ,  Qiang Li

IPC: H01F27/26 ,  H01F27/28

CPC classification number: H01F27/26 ,  H01F27/2804

Abstract: Various examples of an integrated parallel matrix transformer and inductor are disclosed herein. In one aspect, the transformer includes a first magnetic core having a first set of pillars of a first transformer and a second set of pillars of a second transformer and a second magnetic core having a first and second inductor pillar. The first and second magnetic cores can be separate or integrated into one core. The transformer also includes a planar winding structure. The planar winding structure may include a primary winding and a plurality of secondary windings. The primary winding can be configured to equally divide a primary current. The primary winding can extend a number of turns to conduct half of the primary current around the first inductor pillar and the first set of pillars and to conduct half of the primary current around the second inductor pillar and the second set of pillars.

公开(公告)号：US09812978B2

公开(公告)日：2017-11-07

申请号：US15085012

申请日：2016-03-30

Applicant: Virginia Tech Intellectual Properties, Inc.

Inventor： Xiucheng Huang ,  Fred C. Lee ,  Qiang Li

IPC: H02M3/335 ,  H02M1/44 ,  H02M1/08 ,  H02M1/00

CPC classification number: H02M3/33592 ,  H02M1/08 ,  H02M1/44 ,  H02M2001/0048 ,  Y02B70/1475

Abstract: A voltage waveform similar to a waveform of a magnetizing current of an isolation transformer and immune to high frequency oscillatory resonant behavior is developed across a capacitor of a series resistor and capacitor connection connected in parallel with a synchronous rectifier. A simple logic circuit produces a waveform for controlling the synchronous rectifier which is not subject to significant turn on delay or early turn off caused by oscillatory resonances among parasitic inductances and capacitances. Improved timing accuracy of a synchronous converter provides improved power converter accuracy, particularly for flyback converters which are commonly used in converters for supplying power to offline electrical devices but are subject to oscillatory resonant behaviors that cannot be adequately damped at switching frequencies sufficiently high to support miniaturization of adapters.

公开(公告)号：US09735238B2

公开(公告)日：2017-08-15

申请号：US14471404

申请日：2014-08-28

Applicant: Virginia Tech Intellectual Properties, Inc.

Inventor： Xiucheng Huang ,  Weijing Du ,  Qiang Li ,  Fred C. Lee

IPC: G05F1/00 ,  H01L29/20 ,  H01L29/16 ,  H03K17/10 ,  H03K17/567 ,  H02M1/00 ,  H03K17/687

CPC classification number: H01L29/20 ,  H01L29/1608 ,  H01L29/2003 ,  H01L29/7828 ,  H02M2001/0058 ,  H03K17/102 ,  H03K17/567 ,  H03K2017/6875 ,  H03K2217/0036 ,  Y02B70/1491

Abstract: In a cascode switching device, avalanche breakdown of a control transistor and loss of soft switching or zero voltage switching in a high voltage normally-on depletion mode transistor having a negative switching threshold voltage and the corresponding losses are avoided by providing additional capacitance in parallel with a parallel connection of drain-source parasitic capacitance of the control transistor and gate-source parasitic capacitance of the high voltage, normally-on transistor to form a capacitive voltage divider with the drain-source parasitic capacitance of the high voltage, normally-on transistor such that the avalanche breakdown voltage of the control transistor cannot be reached. The increased capacitance also assures that the drain source parasitic capacitance of the high voltage, normally-on transistor is fully discharged before internal turn-on can occur.

公开(公告)号：US20170222483A1

公开(公告)日：2017-08-03

申请号：US15417353

申请日：2017-01-27

Applicant: Virginia Tech Intellectual Properties, Inc.

Inventor： Junjie Feng ,  Qiang Li ,  Fred C. Lee ,  Minfan Fu

IPC: H02J50/12 ,  H02J50/90 ,  H02J7/02

CPC classification number: H02J50/12 ,  H02J7/0042 ,  H02J7/025 ,  H02J50/90

Abstract: In one example, an omnidirectional wireless power transfer system includes high frequency power generator configured to generate a supply of high frequency oscillating power, a number of transmitter-side resonant tank circuits electrically coupled to the high frequency power generator, a receptacle including a number of coils arranged for omnidirectional power transfer to an electronic device placed in the receptacle, and a controller configured to activate individual ones of the transmitter-side resonant tank circuits to wirelessly transmit power to the electronic device through near-field resonant inductive coupling. In one example, the receptacle can be embodied as a bowl, and the controller can activate individual ones of the transmitter-side resonant tank circuits over time to generate an omnidirectional field distribution for wireless power transmission. In other aspects, various transmitter-side and receiver-side tank circuits for coupling independent resonance and ZVS operation are described.

公开(公告)号：US09678521B2

公开(公告)日：2017-06-13

申请号：US14050435

申请日：2013-10-10

Applicant: Virginia Tech Intellectual Properties, Inc

Inventor： Pei-Hsin Liu ,  Fred C. Lee ,  Yingyi Yan ,  Paolo Mattavelli

IPC: H02M3/157 ,  G05F1/46 ,  H02M3/156 ,  H02M1/00

CPC classification number: G05F1/468 ,  H02M3/156 ,  H02M3/157 ,  H02M2001/0012 ,  H02M2001/0025

Abstract: Peak current, valley current or average current mode controlled power converters in either digital or analog implementations obtain a stabilized feedback loop and allow high system bandwidth design by use of an external ramp generator using a slope computation equation or design parameters based on fixing the quality factor of a double pole at one-half of the switching frequency at a desired value The slope of the external ramp waveform is tuned automatically with knowledge of the slope change in the waveform of inductor current of a power converter derived by differentiating a waveform in the current feedback loop. This autotuning of the external ramp generator provides immunity of quality factor change under variations of duty cycle, component values of topological change of the power converter.

公开(公告)号：US20160294278A1

公开(公告)日：2016-10-06

申请号：US15075553

申请日：2016-03-21

Applicant: Virginia Tech Intellectual Properties, Inc.

Inventor： Virginia Li ,  Pei-Hsin Liu ,  Qiang Li ,  Fred C. Lee

IPC: H02M3/04

CPC classification number: H02M3/156 ,  H02M2003/1566

Abstract: A power converter using constant on-time (COT) or ramp pulse modulation (RPM) control achieves more rapid resumption of steady-state operation after a step-up load transient by extending an on-time of a switching pulse by interrupting a ramp voltage waveform that is compared with a threshold that equals a threshold voltage at the termination of a switching pulse or increasing a voltage with which the ramp voltage is compared. These techniques are applied to both single-phase and multi-phase power converters.

Abstract translation: 使用恒定导通时间（COT）或斜坡脉冲调制（RPM）控制的功率转换器通过通过中断斜坡电压来延长开关脉冲的导通时间来实现升压负载瞬变之后的更快恢复稳态操作 该波形与等于开关脉冲终止时的阈值电压的阈值进行比较，或增加与斜坡电压进行比较的电压。 这些技术适用于单相和多相功率转换器。

公开(公告)号：US09318946B2

公开(公告)日：2016-04-19

申请号：US14087076

申请日：2013-11-22

Applicant: Virginia Tech Intellectual Properties, Inc.

Inventor： Weiyi Feng ,  Fred C. Lee

IPC: H02M3/337 ,  H02M1/36 ,  H02M1/00

CPC classification number: H02M1/36 ,  H02M3/3376 ,  H02M2001/0058 ,  Y02B70/1433 ,  Y02B70/1491

Abstract: By setting switching instants of a switching circuit of a resonant power converter based on current in a resonant circuit reaching a current limit of a current limitation band, soft start-up of the power converter can be achieved to avoid or limit electrical stress with full control over a trade-off between time required to settle to a full load steady-state mode of operation and the amount of electrical stress permitted while soft start up switching frequency is automatically optimized.

Abstract translation: 通过基于达到电流限制带的电流限制的谐振电路中的电流来设置谐振功率转换器的开关电路的开关时刻，可以实现功率转换器的软启动，以完全控制以避免或限制电应力 在软启动切换频率自动优化的同时，在满足全负载稳态运行模式所需的时间和允许的电压应力之间进行权衡。

公开(公告)号：US09276480B2

公开(公告)日：2016-03-01

申请号：US14140008

申请日：2013-12-24

Applicant: Virginia Tech Intellectual Properties, Inc.

Inventor： Weiyi Feng ,  Fred C. Lee ,  Shu Ji

IPC: H05B37/00 ,  H05B39/00 ,  H05B41/00 ,  H02M3/335 ,  H05B33/08 ,  H02M1/00 ,  H02M3/337

CPC classification number: H02M3/33507 ,  H02M3/33561 ,  H02M3/337 ,  H02M2001/0058 ,  H05B33/0815 ,  H05B33/0827 ,  Y02B70/1433 ,  Y02B70/1491

Abstract: Pulse width modulation is provided for controlling a resonant power converter, particularly for dimming of light emitting diode arrays without loss of efficiency. Dynamic oscillation due to the beginning of a pulse width modulated pulse burst is limited by shortening of the first and/or last pulse of a pulse bust such that the first pulse of a subsequent pulse burst close to or to connect with a full load steady-state voltage/current trajectory of the power converter. Pulse shortening made be made substantially exact to virtually eliminate dynamic oscillation but substantial reduction in dynamic oscillation is provided if inexact or even performed randomly.

Abstract translation: 提供脉宽调制用于控制谐振功率转换器，特别是用于调光发光二极管阵列而不损失效率。 由于脉冲宽度调制脉冲串的开始而产生的动态振荡受到脉冲胸部的第一和/或最后脉冲的缩短的限制，使得后续脉冲的第一脉冲突然接近或与全负载稳态连接， 电源转换器的状态电压/电流轨迹。 基本上精确地实现脉冲缩短以实质上消除动态振荡，但是如果不精确或甚至随机地执行，则提供动态振荡的显着降低。