Design and Analysis of a Repetitive Current Controller for a Single-Phase Bridgeless SEPIC PFC Converter

Abstract

This paper studies a repetitive controller design scheme for a bridgeless single-ended primary inductor converter (SEPIC) power factor correction (PFC) converter to mitigate input current distortions. A small signal modeling of the converter is performed by a fifth-order model. Since the fifth-order model is complex to be applied in designing a current controller, the model is approximated to a third-order model. Using the third-order model, the repetitive controller is designed to reduce the input current distortion. Then, the stability of the repetitive controller is verified with an error transfer function. The proposed controller performance is validated by simulation, and the experiment results show that the input current total harmonic distortion (THD) is improved by applying the proposed controller for an 800 W bridgeless SEPIC PFC converter prototype.

Sliding Mode Control of the Isolated Bridgeless SEPIC High Power Factor Rectifier Interfacing an AC Source with a LVDC Distribution Bus

“…The benefits of applying sliding-mode control in the proposed converter with the mentioned constraints can be observed in terms of simple implementation, fast and robust response, and general improvement of quality indicators such as high power factor (>0.98) and reduced THD (<5%). These quality indicators for the entire range of operation of the converter are above the quality levels reported before for the same topology or for modified versions of the basic circuit [14][15][16][17][21][22][23][24][25][26][27][28].…”

“…This is carried out by an inner control loop that normally processes the input current and is complemented by an outer loop regulating the output voltage in the case of rectifiers operating as pre-regulators. In addition, discrete-time control techniques such as repetitive control have been applied to control the SEPIC rectifier [27]. With this technique, the THD is high at low power levels, but enters in the permissive range for 50% of the nominal power, which suggests that there is still an important gap to improve the rectifier performance in terms of THD.…”

“…. Considering initial conditions equal to zero in Equation (27) and assuming that ω a ω, the current of the input inductor is given by the following:…”

Special Issue “Intelligent Control in Energy Systems”

“…In [8], a repetitive controller used in a SEPIC PFC converter was designed using a third-order model approximation-instead of fifth-order for reasons of simplicity in order to reduce the input current distortion and the stability of the controller was verified with an error transfer function. The proposed controller was then validated by simulation in 100 W to 800 W load conditions in buck and boost mode.…”

A discrete repetitive adaptive sliding mode control for DC-DC buck converter

“…The majority of these works are designed under a particular type (constant or slowly time-varying) and bounded disturbances. This is not always the case; in fact, various industrial applications, such as rotating machine tools, 20 robot manipulators, 21 converters, 22 and so on, are affected by periodic disturbances. Among many control strategies for periodic disturbances rejection, the repetitive control (RC) has received widespread attention during the last two decades.…”