A passive lossless snubber cell is proposed to improve the turn-on and turnoff transients of the MOSFET’s in nonisolated pulsewidth modulated (PWM) dc/dc converters. Switching losses and EMI noise are reduced by restricting di=dt of the reverse-recovery current and dv=dt of the drain–source voltage. The MOSFET operates at zero-voltage-switching (ZVS) turnoff and near zero-current-switching (ZCS...

A closed loop bidirectional ac to ac buck boost converter circuit using power MOSFET is analyzed for reducing the output voltage sag and improving efficiency of the converter. The regenerative dc snubbers are used directly to power semiconductor switches to absorb energy stored in stray line inductances. These dc snubbers enhance the conversion efficiency as it has very simple structure consist...

‎ In this paper, the stand-alone photovoltaic system for cathodic protection of underground pipelines is presented. The proposed system offers continuous and automatic adjustment of the applied voltage so that the buried pipelines receive the exact current. A modified perturb and observe (P&O) algorithm for maximum power point tracking (MPPT) is used to improve dynamic and steady state performa...

Due to increasing concerns on the power quality, power factor correction (PFC) has become an important issue in light-emitting diode (LED) lighting applications. A boost converter is one of the most well-known PFC topologies, due to its simple circuitry, simple control scheme and small number of passive components. Even though a boost converter is recognized as a typical PFC converter, its outp...

This paper presents and implements a single-stage high-power-factor light-emitting diode (LED) driver with coupled inductors, suitable for streetlight applications. The presented LED driver integrates an interleaved buck-boost power factor correction (PFC) converter with coupled inductors and a half-bridge-type series-resonant converter cascaded with a full-bridge rectifier into a single-stage ...

This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way,...

This paper focuses on the non-inverting buckboost converter supplying an adjustable DC voltage to a WCDMA RF power amplifier (RFPA) in order to improve the system efficiency under different transmitted RF power levels. It is shown that precise output voltage positioning and low output voltage ripple over a wide output voltage range, including buck, boost and buck/boost transition modes, can be ...