Single-Phase AC-DC Cascaded Boost- Cûk (CBC) Converter for High Step-up Applications Using Common Part Sharing Method (CPSM)

Abstract

Due to the rising need of renewable energy the importance of the development of more efficient circuits that transform energy has also risen. The multi-pulse AC-DC converters used in wind turbines often prove to be insufficient in the elimination of harmonics. This leads to additional active power filters, which operate at high switching frequencies, being used and the cost of the system being increased.

The chief advantage of Boost converter topology is the continuity of the input current, which is very important for renewable energy applications since most renewable energy sources have a better performance when their electrical current is continuous.

The reason for using bridgeless Boost converters is the reduced current input current ripple, but they also should provide an output voltage higher than the peak input voltage. The current that passes through power converter devices from the main supply results in high Total Harmonic Distortion (THD) and reduced Power Factor (PF). Thus power factor correction helps greatly in the reduction of input power loss which may emanate from input current harmonics.

Even though a bridgeless power factor correction converter suffers from the difficulty of implementing control because of two switches, conduction losses can be reduced by a bridgeless topology from rectifying bridges; thus, increasing overall system efficiency. Additionally, a bridgeless topology has the advantage of reduction in the total harmonic distortion resulting from input diode reduction.

This letter details the design and function of a novel topology of Cascaded Boost-Cûk(CBC) converter which combines the Boost converter with an isolated Cûk converter as a series output module in order to obtain high step-up ratio and to overcome the drawbacks faced when using conventional circuits. The demand for high voltage, efficient and lossless converters has increased in the 21st century. In order to facilitate the demand cascaded converters has been proposed which not only provides high performance in terms of efficiency, reduction in Total Harmonic Distortion (THD) of the input current and improved input power factor (PF) but also proper voltage regulation at all duty cycles. The proposed CBC converter has been simulated and verified using PSIM environment and is appropriate for high voltage and high performance applications. Similar works has been done in cascading Boost- SEPIC converters using common parts sharing method.