Modeling analysis and design of current mode controlled ultra lift luo converter

Abstract

Renewable energy system, electric vehicle, and telecommunication industry require relatively stable DC-DC switching power converters with high gain and enhanced noise immunity. In recent years, current-mode controller based power converters have gained extensive research interest due to their advantages such as good dynamic response, improved line regulation, cycle by cycle current limiting. One of the latest power electronic converters is ultra-lift Luo converter (ULC). The effects of the parasitic elements that limit the output voltage and converter s efficiency are eliminated by Luo converters. ULC produces high output voltage with small ripples by using voltage-lift (VL) technique. ULC is used in telecommunication, battery chargers, energy efficient lighting systems, computer peripherals, automotive applications, renewable energy systems, power supply for energy efficient drives and medical equipment. The three different types of current-mode controllers such as peak current-mode controller (PCM), average current-mode controller (ACM) and hysteresis current-mode controller (HCM) for high gain ultra-lift Luo converter newline(ULC) are discussed in this thesis. At first, the small-signal modeling of ultra-lift Luo-converter is done using state space averaging technique. The stability of the outer voltage loop in the controller is analyzed using Eigen value theory. Then the behaviour of the constant frequency peak current-mode controller based ULC is analyzed using an algorithm. PCM controller is modelled using Perturbation theory, Sample-and-Hold theory and Modified Pade Approximation method. Slope compensation is used for accurate margin of stability. newline newline