Analysis And Study On Modeling Of Switched DC-DC Boost Converters

Step-up conversion circuit is widely used in today’s electronic devices, especially for a battery-powered device. The converter allows the use of low voltage of the battery power supply, and then through the booster type DC-DC converter converts need high voltage circuit. In order to ensure the booster type DC-DC conversion circuit of the long-term and reliable work, understand the circuit principle is very important. This includes know non-ideal factors, the transient response of the circuit and the way the DC-DC converter work and so on. Deep understanding of the content type to find booster DC-DC converter may be unstable factors have a key role. In order to optimizing the performance of DC-DC boost converter, and provide theoretical basis for the actual hardware circuit design, developed a variety of mathematical model.This article first introduced the DC-DC switching converter modeling development present situation, more focus on the current application of state space average method and circuit averaging method. On the advantages and disadvantages of all kinds of modeling method has carried on the simple comparison, and modeling method of DC-DC switching converters development trend is prospected. Then introduces the booster type DC-DC switching converter two work modes: continuous conduction mode of CCM and discontinuous conduction mode DCM has carried on the simple introduction. For each mode, the ideal and non-ideal circumstances derivation formula of output ripple voltage, efficiency, finally comprehensive compare and analysis the advantages and disadvantages of CCM mode and DCM mode.Next, the state space average model of PWM is introduced, and then deduced respectively the CCM and DCM mode PWM switch expression, finally get their booster type converter small signal circuit model. In front, on the basis of ideal and non-ideal conditions were deduced, CCM mode and DCM mode transformation equation.Finally, the comprehensive comparison and analysis on the mode of CCM and DCM mode and boost DC-DC converter conversion equations of open-loop gain, resonance frequency, factor Q and zero expression, finally obtained for booster type DC-DC, the conclusion of DCM mode has more advantages, the booster type DC-DC converter circuit design provides a theoretical guidance.