Jingchao Ni - IEEE Xplore Author Profile

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Utility power lines voltage levels vary in different geographical locations, ranging from 208 to 480 Vrms. Power factor correction (PFC) converters are typically designed for a particular input voltage and do not accept a wide range of line voltages. This results in multiple product designs and revisions and increased production costs to accommodate the various ac voltage levels used around the wo...Show More
Wide-bandgap (WBG) devices, like devices based on Silicon-Carbide (SiC) and Gallium-Nitride (GaN), incorporate smaller capacitances and thus faster switching dynamics than traditional semiconductor devices. The size of these capacitances reaches the same order of magnitude than the parasitic elements of the printed circuit board (PCB). This has to be addressed effectively, in order to achieve the ...Show More
Totem-pole FC has the potential to achieve high efficiency and power density by using GaN HEMTs as the high-frequency switching device. With the advent of 600-650V rated commercial GaN HEMTs, the totem-pole PFC is expected to emerge as the dominant topology for the front-end of telecom and data center power supplies. Like most bridgeless topologies, totem-pole PFC generates a large amount of commo...Show More
Small wind energy conversion systems (WECSs) are becoming an attractive option for distributed energy generation. WECSs use permanent-magnet synchronous generators (PMSGs) directly coupled to the wind turbine and connected to the grid through a single-phase grid-tie converter. The loading produced on the dc link is characterized by large ripple currents at twice the grid frequency. These ripple cu...Show More
Synchronous interleaved boost converters (SIBCs) result in lower ripple currents and bidirectional power flow. The boost topology has a non-minimum phase characteristic, producing instability problems when a large bandwidth is required. Linear controllers inherently limit the boost controller bandwidth, resulting in a slow response. In this paper, state-trajectory control of the SIBC based on boun...Show More
A reverse control scheme for modular telecommunications battery chargers with solar panel input is investigated in this paper. Small-signal analysis is performed for a typical state-of-the-art multi-stage converter and the reverse control transfer functions are presented and used to develop a linear control strategy, which is validated using simulations and experimental results.Show More
A swinging bus scheme is investigated in this paper to eliminate undesirable low-frequency ripple current reflection in fuel cells. The swinging bus is thoroughly characterized under various loading conditions to establish a behavioral model. As a result, a general control scheme and signal processing for buck- and boost-derived power converters are obtained. A digital filter in the form of a movi...Show More