Investigation on two level cascaded positive output dc dc boost converter with multi loop controllers

Abstract

In recent years, the demand for power electronic devices in various applications such as hybrid electric vehicles, renewable energy sources, electric traction, medical equipment and much more has been grown tremendously. For these applications, several DC-DC converter topologies such as boost converters, buck converters, buck-boost converters, KY, SEPIC and Luo Converters (LCs) have been developed. Of these converters, Luo converters are the most commonly used boost topology for higher voltage conversion ratio applications and higher efficiency. The Luo-Converters are predominantly classified into three types: voltage lift, super lift, and ultra-lift. In many applications, Voltage Lift (VL) configuration has been used effectively due to the fact that the converter output voltage gets boosted up in arithmetic progression. Whereas in Super Lift (SL) technique, the output voltage gets boosted up in geometric progression and the voltage transfer gain is also increased in power series efficiently. The SL technique based Luo converter is classified as Positive Output SLLC and Negative Output SLLC. Although the SL technique based Luo converter increases the output voltage in geometric progression, the circuits are somewhat complex. As a result, cascaded boost converters have been developed which can enhance the output voltage in geometric progression using power law with simpler structure. Such converters are entitled as Cascaded Positive Output Boost Converter (CPOBC) and Cascaded Negative Output Boost Converter (CNOBC) in order to distinguish this converter from the VL and SL techniques based converters. A Two-Level Cascaded Positive Output Boost Converter (TLCPOBC) based on Super Lift technique is considered in this research. newline