Other

The University of Hongkong

Versitech, Inc.

Sinan Li

Shu Yuen Ron Hui

Siew Chong Tan

Ting Leung Albert Lee

Shu Yuen Hui

Wu Chen

Chi Kwan Lee

Wenxing Zhong

Yue Guo

Wenlong Qi

Weijian Jin

Ron Shu Yuen Hui

Ting Leung Lee

A power converter circuit includes: a direct current (DC) side; a first passive network; a first current switching network; at least one floating capacitor; a second current switching network; a second passive network; and an alternating current (AC) side. The first passive network is connected between the DC side and the first current switching network for linking the DC side and the first current switching network. The first current switching network comprises at least four serially linked switches for switching the power converter circuit between switching cycles. The at least one floating capacitor is connected to the first current switching network. The second current switching network comprises two pairs of switches for providing an interface between the first current switching network and the second passive network. The second passive network is connected between the second current switching network and the AC side.

AC-to-DC and DC-to-AC power conversion

A system and a control method for generating multiple independent alternating current (AC) voltages from a direct current (DC) voltage source in a single-inductor multiple-output (SIMO) inverter are disclosed. The system comprising: a DC voltage source () for providing electrical energy; a front-stage DC-DC power converter () comprising exactly one inductor as an energy storage element for power conversion and a main switching element; a plurality of selectable output branches (), wherein each output branch comprises an output selection switch (), a resonant tank (), and a transmitter coil (), wherein the resonant tank converts output power of the DC-DC power converter into AC power for feeding the transmitter coil; and a controller () for determining ON/OFF states of the main switching element and the output selection switch of each of the output branches. The system and the method can provide simple, compact, scalable, and low-cost solutions by employing only a single inductor to drive multiple independent transmitting coils.

Single-stage single-inductor multiple-output (SIMO) inverter topology with precise and independent amplitude control for each AC output

In many power electronics systems, there is an intermediate DC-link stage for facilitating the power processing of different sources to their loads. A device called a plug-and-play ripple pacifier (RP) directly plugged into the DC-link, and actively removes undesired DC-link ripple, thereby eliminating the reliance on electrolytes capacitors for stabilizing the system and remove ripple. Importantly, the use of this device is non-invasive to the operation of its host systems, and requires no modification of existing hardware. It is suitable for the protection of DC utilities/systems and can also be used as a direct replacement of ripple-canceling E-Caps in power converters device.

Plug-and-play ripple pacifier for DC voltage links in power electronics systems and DC power grids

A single-stage AC-DC single-inductor multiple-output (SIMO) LED driver uses a single inductor (L) to drive multiple independent LED strings (-) with Power Factor Correction (PFC). The driver uses a diode bridge () to achieve initial AC to DC conversion. The output of the bridge () is provided to a buck converter whose output is shared with multiple LED strings by a time division multiplex circuit. Feedback is used to separately control the current supplied to each LED string by using a separate reference for each string and controlling the width of the current pulse provided to a string. Current balancing in every LED string can be achieved with the same voltage reference without the need for additional circuitry.

AC-DC single-inductor multiple-output LED drivers

Provided is a current mirror circuit () for balancing respective currents in a plurality of parallel circuit branches () in a target circuit (), the current mirror circuit () including: a plurality of balancing transistors (), each having a connector (), an emitter (), and a base (), the collector () and emitter () of each balancing transistor () connected in series with a respective circuit branch (); a selection circuit () that connects the circuit branch () having the smallest current amongst the circuit branches () to the bases () of each balancing transistor; and an isolation circuit () that isolates circuit branches () having an open circuit fault from the rest of the target circuit (). An associated method of balancing respective currents in a plurality of parallel circuit branches () in a target circuit () is also provided.

Current mirror circuit and method

The present invention provides a current balancing circuit and method for balancing the respective currents in a plurality of parallel circuit branches in a target circuit. The current balancing circuit including: a plurality of balancing transistors, each having a collector, an emitter, and a base, the collector and emitter of each balancing transistor connected in series with a respective circuit branch; and a selection circuit for selectively connecting the circuit branch having the smallest current amongst the circuit branches to the bases of each balancing transistor.

Growing community of inventors

Hong Kong, China

Sinan Li