Virginia Tech Intellectual Properties, Inc.

Other

Qiang Li

Fred C Lee

Bin Li

Chao Fei

Pei-Hsin Liu

Xiucheng Huang

Yipeng Su

Yuchen Yang

Zhengyang Liu

Daocheng Huang

Junjie Feng

Syed Bari

Shuo Wang

Weiyi Feng

Mingkai Mu

Furong Xiao

Zhengrong Huang

Ahmed Nabih

Hao Xue

Dongbin Hou

Yadong Lyu

Hongfei Wu

Yi-Hsun Hsieh

Weijing Du

Wenli Zhang

Xuebing Chen

Mohamed Ahmed

Owen Jong

Minfan Fu

Mohamed Hassan Abouelella Ahmed

Xin Lou

Virginia Li

Feiyang Zhu

In one example, a planar 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 planar coil arrangement including a number of coils arranged for omnidirectional power transfer to a device placed over the planar coil arrangement, and a controller configured to activate individual ones of the transmitter-side resonant tank circuits to wirelessly transmit power to the device. In one aspect, 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.

Planar omnidirectional wireless power transfer system

Various examples of systems and methods for a coupled inductor winding structure for common-mode noise reduction is described herein. The coupled inductor structure can include a magnetic core including a first leg, a second leg, and a center leg; and a planar winding structure. The planar winding structures can include a first inductor winding for a forward path of a first phase of a power converter; a second inductor winding for a forward path of a second phase of the power converter; a third and fourth inductor winding for a return path. The third inductor winding having at least one turn interleaved within the number of first leg turns of the first inductor winding and configured to achieve unity coupling. The fourth inductor winding having at least one turn interleaved within the number of second leg turns of the second inductor winding and configured to achieve unity coupling.

Coupled inductor winding structure for common-mode noise reduction

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.

Multi-phase integrated coupled inductor structure

Various examples of magnetic integration of matrix transformers with controllable leakage inductance are described. In one example, a transformer includes a magnetic core comprising a plurality of core legs and a leakage core leg. The leakage core leg is positioned among the plurality of core legs to control a leakage inductance of the transformer. The transformer also includes a planar winding structure. The planar winding structure includes a primary winding and a plurality of secondary windings. The primary winding and the plurality of secondary windings extend in a number of turns around the plurality of core legs, without a turn around the leakage core leg, to further control the leakage inductance of the matrix transformer.

Magnetic integration of matrix transformer with controllable leakage inductance

Aspects of direct current (DC)-DC converters with an integrated matrix transformer and multiphase current doubler rectifiers are described. In some examples, a DC-DC converter can include a matrix transformer that has multiple magnetically integrated transformer components that are magnetically integrated using transformer components that share a top plate and a bottom plate. A multiphase current doubler rectifier can include multiple synchronous rectifiers corresponding to the plurality of transformer components of the matrix transformer.

High current DC-DC converter with integrated matrix transformer and multiphase current doubler rectifier

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.

Integrated parallel matrix transformer and inductor

Aspects of an efficient, wide voltage range, power converter system are described. In one example, a power converter system includes a first power converter, a second power converter, and a controller for the power converter. An input of the first power converter and an input of the second power converter are connected in series across an input voltage for the power converter system, and an output of the first power converter and an output of the second power converter are connected in parallel at an output of the power converter system. The controller is configured to regulate the second power converter and to determine whether or not to regulate the first power converter based on the input voltage for the power converter system and an output voltage of the power converter system, among other factors, for greater efficiency of the power converter system over wider input and output voltage ranges.

Efficient wide voltage range quasi-parallel voltage regulator

Three-phase interleaved LLC and CLLC resonant converters, with integrated magnetics, are described. In various examples, the primary sides of the phases in the converters rely upon a half-bridge configuration and include resonant networks coupled to each other in delta-connected or common Y-node configurations. The secondary sides of the phases can rely upon a full-bridge configurations and are coupled in parallel. In one example, the transformers of the phases in the converters are integrated into one magnetic core. By changing the interleaving structure between the primary and secondary windings in the transformers, resonant inductors of the phases can also be integrated into the same magnetic core. A multi-layer PCB can be used as the windings for the integrated magnetics.

Interleaved converters with integrated magnetics

A matrix transformer particularly suited to large voltage step-down, high current applications achieves increased good current sharing uniformity or air gap and electrical characteristics and reduced or eliminating termination losses, core losses and winding losses with a unitary magnetic core structure featuring sheets of magnetic material and a two-dimensional array of pillars on which windings, oriented in opposite directions on pillars that are adjacent in orthogonal directions, can be formed or placed comprising metallization on or embedded in a printed circuit board (PCB) structure. Magnetic flux density is reduced by at least one-half by dividing the magnetic flux in each pillar into two paths of increased width in the sheets of magnetic material. Magnetic flux density may be further decreased and flux uniformity improved by extending the sheets of magnetic material beyond a periphery defined by the pillar array.

Matrix transformer and winding structure

A bidirectional three-phase direct current (DC)/DC converter and method are disclosed. The converter comprises a primary side comprising a DC bus having a positive side and a negative side, a first set of rectifiers connected between the positive side and the negative side of the DC bus, a first set of M resonant tanks connected to a respective rectifier of the first set of rectifiers and a first set of M transformers. Each transformer is connected to a respective resonant tank. Each resonant tank comprises a resonant capacitor and a resonant inductor. The secondary side of the converter is fully symmetrical to the primary side of the converter to ensure that the conversion gain in the forward and reverse directions is the same.

Bidirectional three-phase direct current (DC)/DC converters

An amount of charge transferred by a power converter is estimated by developing a signal that is a combination of signals representing an output voltage of a power converter and an inductor current of the power converter, charging a capacitor with a current proportional to that signal and comparing a voltage developed across the capacitor due to that charging to develop a signal for initiating a pulse to control input of power from a voltage source to the power converter. By using a signal developed in this way, response to both step-up and step-down transients can be improved and, in multi-phase embodiments, ripple cancellation problems such as noise susceptibility and loss of pulse generation can be entirely avoided.

Inverse charge current mode (IQCM) control for power converter

Various examples are provided related to switched-capacitor converters (SCCs) with multi resonant frequencies. In one example, a multi resonant SCC (MRSCC) includes a series of switches coupled between an input voltage and an output connection; a pair of diodes coupled across the output connection; and a resonant circuit coupled at a first end between first and second switches of the series of switches and at a second end between the pair of diodes. The resonant circuit can comprise a resonant tank including a first capacitor and a resonant inductor, and a resonant component in parallel with at least a portion of the resonant tank. The resonant component can be connected across the resonant tank or across the resonant inductor. The MRSCC topology can also be used with higher voltage conversion ratio converters.

Switched capacitor converters with multi resonant frequencies

A variable direct current (DC) link power converter is described. In one example, the power converter includes a first converter stage configured to convert power from a power source to power at an intermediate link voltage and a second converter stage configured to convert the power at the intermediate link voltage to power for charging a battery. The power converter further includes a control system having an intermediate link voltage regulation control loop configured, in a first mode of operation, to regulate the intermediate link voltage through the first converter stage based on a voltage of the battery, and a ripple regulation control loop configured to sense a charging current for the battery and regulate a gain of the second converter stage based on the charging current to reduce ripple in the charging current. A new configuration of transformer suitable for use with the power converter is also described.

Variable DC link converter and transformer for wide output voltage range applications

Aspects of capacitor voltage ripple reduction in modular multilevel converters are described herein. In one embodiment, a power converter system includes a modular multilevel converter (MMC) electrically coupled and configured to convert power between two different power systems. The MMC includes one or more phase legs having a cascade arrangement of switching submodules, where the switching submodules include an arrangement of switching power transistors and capacitors. The MMC further includes a control loop including a differential mode control loop and a common mode control loop. The differential control loop is configured to generate a differential control signal based on a target modulation index to reduce fundamental components of voltage ripple on the capacitors, and the common mode control loop is configured to inject 2order harmonic current into a common mode control signal to reduce 2order harmonic components of the voltage ripple on the capacitors.

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Blacksburg, VA, United States of America

Qiang Li