Active-Clamp Resonant Power Factor Correction Converter With Output Ripple Suppression

Abstract

An active-clamp resonant power factor correction converter with output ripple suppression is proposed and analyzed. It combines a buck power factor correction (PFC) unit and a resonant dc-dc unit by sharing one active switch. With another active-clamp switch, a recycling path is built to recover the leakage inductance energy of transformer, which improves the efficiency and the voltage stress of active switch. The effect of voltage ripple of dc link on output can be suppressed by fast voltage mode control loop. Therefore, low output current or voltage ripple can be achieved. With small voltage ripple across output of buck unit, the turn on time of active switch is almost constant in a half line cycle. Therefore, power factor correction can be achieved with inductor current of buck unit operating in discontinuous conduction mode (DCM). Finally, a 65W high power factor (PF) converter prototype for LED driver application with 91.08% peak efficiency and low output current ripple is built to verify the analytical results.

Discrete State-Feedback Control Design with D-Stability and Genetic Algorithm for LED Driver Using a Buck Converter

“…Now, the problem is reduced to determine optimal values of the controller gains. By synthesizing (8) in system (6), assuming that r f 0, gives the closed-loop system…”

“…e following result gives su cient LMIs conditions to guarantee the global asymptotic convergence of the tracking controller: Theorem 1. Given system (6), and the comparator integrator control law (9), the closed-loop error system ( 5) is asymptotically stable if there exists a symmetric matrix X X T > 0 and a matrix W such that…”

“…Corollary 1. Given system (6), and the comparator integrator control law (9), the close-loop error system ( 5) is asymptotically stable if there exists a positive scalar r, a symmetric matrix X X T > 0 and a matrix W such that…”

“…is phenomenon causes the current to have a great increment in its value when the voltage has small variations [1][2][3][4][5][6][7][8][9][10][11].…”

“…To our knowledge, there are few studies on designing discrete state-feedback controllers with genetic algorithms to have the desired characteristic of a closed-loop LED driver, so the study of such problems remains important and challenging and is of both practical and theoretical importance. e buck converter is used as a LED driver because it has been used with satisfactory results in LED lighting applications [6]. is converter is a minimum phase system, and due to this property, it is easy to control it [2].…”