Boost Converter Topology Research Articles

A Single Switch Split DC-Rail Boost Converter Topology Operated Under Steady-State Unbalanced Load Conditions in Discontinuous Conduction

A single switch split dc-rail boost converter topology is described that uses a mutually coupled two winding inductor to balance the voltage drop across both of its capacitor smoothed split dc-rail input and output voltage terminals. The operation of the converter topology is described in discontinuous conduction with an unbalanced output load in steady-state. The resultant converter topology obtains balanced input and output voltages under extreme unbalanced load conditions without requiring extra converter control features. A current sharing action is described between the two coupled windings during both the switch on-time and off-time. This action is responsible for the voltage balancing feature of the converter when the converter load is unbalanced between the two output dc voltage rails. Simulations and experimental results are used to illustrate the nature of the winding current waveforms that produce this current sharing action. Load imbalances exceeding 3:1 can easily be compensated for, and simulations and experimental results show that typical deviations of the converter input and output voltages can be limited to within the range 1% to 8% for load imbalances of up to 2:1. The voltage imbalance experienced in the two dc rail output voltages is subject to design choices and linked to the winding leakage inductance and dc voltage gain.

Modeling and Simulation of a Novel Switched Reluctance Motor Drive System with Power Factor Improvement

This study presents a novel Switched Reluctance Motor (SRM) drive system with power factor improvement. Recently, many of the converters with variable speed drives have no input power factor correction circuits. This results in harmonic pollution of the utility supply, which should be avoided. The effect of power factor variation in terms of harmonic content is also analyzed in this study. The different operations like single pulse, soft chopping and hard chopping modes are done with and without a power factor controller. This study describes the buck - boost converter topology with above said methods for SRM drive. The boost converter is used to improve the input sinusoidal current and the buck converter is used to regulate the dc source voltage. The proposed topologies were simulated using MATLAB / Simulink software package and the results were obtained. The computer simulation results support the proposed methods.

Using the Multilevel Imbricated Cells Topologies in the Design of Low-Power Power-Factor-Corrector Converters

Power-factor-corrector (PFC) converters are now commonly used in low-power supply systems connected to AC networks. In addition to their basic PFC properties, they constitute the best technical solution to directly obtain the compatibility with a large range of AC voltages provided by different distribution networks around the world (typically, from 85 to 265 V rms). It is the main application of these converters. This function is achieved with an additional cost and volume, and this extra price to pay needs to be minimized. In this context, we first recall the main approaches of the design of conventional PFCs based on the boost converter topology. We emphasize the different critical points of the sizing that mainly concern the input choke and the silicon devices, in regard with the choice of the switching frequency. Few ways of improvement are then presented for these conventional PFCs. In a second part, always in the context of a large input voltage range, we consider the possibility to introduce the multi-level concept to reduce the input choke and filters. A solution using a multi-level flying capacitor two-cell converter is presented. It is shown that it can lead to a significant increase of the performances, with several options of sizing which can be suited to different requirements of the applications.

New Two-Inductor Boost Converter With Auxiliary Transformer

A new, two-inductor, two-switch boost converter topology and its variations suitable for applications with a large difference between the input and output voltage are described. The output voltage regulation of the proposed converters is achieved in a wide load and input-voltage range with constant-frequency control by employing an auxiliary transformer that couples the current paths of the two boost inductors.

AC–DC converter with unity power factor and minimum harmonic content of line current: design considerations

The paper describes some important design considerations in developing a variable three-phase AC–DC converter with unity power factor and the minimum harmonic content of the line current using boost converter topology. The design details of expanding a single-phase converter into a three-phase system are presented. The article also describes the major problems encountered in carrying out such essential modifications, together with their practical solution. A detailed circuit design is included. The prototype circuit was tested for both resistive and inductive loads. The results of operating the converter with a typical DC motor load are also presented.

Mathematical modelling of quasi-resonant converters

A method to determine the small-signal control-to-output transfer function of quasi-resonant converters operating with continuous current is presented. The design of the feedback loop and compensation network becomes easier by this approach. Investigation is carried out using the boost converter topology.

Zero-voltage switching boost converter for power factor correction

A modified boost converter topology with zero-voltage-switching and output voltage isolation for power factor correction is presented. It is shown this new converter topology provides a transformer core resetting mechanism with component stresses which are identical to those in the conventional boost converter. The proposed topology achieves zero-voltage switching and proper transformer-core resetting by utilizing the resonance phenomenon that exists between the parasitic capacitance of the switch and the magnetization inductance of the transformer. Based on the steady-state analysis presented, control characteristic curves are derived. Simulation and experimental results are reported to verify the performance of the converter and its steady-state analysis.

Feed-forward active filter for output ripple cancellation

An active filter for DC-DC converter ripple cancellation is described and demonstrated. The feed-forward technique used applies to any converter with an output filter inductor. The technique is inherently stable, performs in both continuous and discontinuous conduction modes, and applies to both square-wave and resonant converters. A suitable linear amplifier, combined with a current transformer, implements it with low loss. An adaptive tuning scheme compensates for inductance variation and drift. Operation is demonstrated with buck, push-pull, and boost converter topologies. The result is output ripple below 10 mV RMS, effective on converters with outputs as low as 2 V and currents above 30 A.