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Light-emitting diodes (LEDs) are widely used in street lighting, landscape lighting, liquid crystal display (LCD) backlighting, healthcare, etc. As an important part of LED lighting products, LED driver plays a vital role in maintenance costs reduction, energy saving and lifetime prolongation. In this paper, a single-stage LED driver is proposed, which is integrated by a totem-pole bridgeless power factor correction (PFC) unit and several modular LCL-T resonant rectifiers. The totem-pole bridgeless PFC unit and the LCL-T resonant rectifiers are integrated by sharing switches, which can simplify the circuit and reduce the system cost. The output current can be regulated by applying the variable inductor control. Constant duty cycle and fixed switching frequency operation can be achieved as well. The operating principle and the performance of the proposed converter are analyzed in this paper. In addition, a precise parameter design method is proposed by considering the high-order harmonics. At last, an experimental prototype is established to validate the proposed parameter design and variable inductor control method. [ABSTRACT FROM AUTHOR]

An improved two-stage model predictive current control (MPCC) for three-phase three-level converters in the paper, which can simultaneously achieve common-mode voltage (CMV) reduction, effective dc-link capacitor voltage control, and decreased computational burden, is proposed. Compared to the other current control strategies, it has the capability of handling multiple control objectives and possesses a simple structure. Furthermore, it greatly reduces the CMV since the peak CMVs of all the candidate voltage vectors are constrained to be less than one sixth of the dc-link voltage. In addition, an optimal two-stage voltage vector selection mechanism is employed in the proposed method. It helps to significantly reduce the computational complexity. Simulation and experimental results are provided to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]