Optimum Injected Current Harmonics to Minimize Peak-to-Average Ratio of LED Current for Electrolytic Capacitor-Less AC–DC Drivers

Author

Ruan, Xinbo ; Wang, Beibei ; Yao, Kai ; Wang, Shu

Author_Institution

Aero-Power Sci-Tech Center, Nanjing Univ. of Aeronaut. & Astronaut., Nanjing, China

Volume

26

Issue

7

fYear

2011

fDate

7/1/2011 12:00:00 AM

Firstpage

1820

Lastpage

1825

Abstract

The lifetime of an ac-dc LED driver can be increased by eliminating the electrolytic capacitor. Unfortunately, it results in pulsation with twice the line frequency in the driving current. Injection of the third and fifth harmonics into the input current can reduce the peak-to-average ratio of the driving current, which is beneficial for reliable operation of the LEDs. This letter discusses the relationship between the peak-to-average ratio and the injected harmonics, and the optimum injected third and fifth harmonics to minimize the peak-to-average ratio are obtained, while ensuring that the input power factor is higher than 0.9 to meet the regulatory requirement such as the ENERGY STAR. This optimum injected current harmonics is verified by a flyback-based electrolytic capacitor-less LED driver with 25 V, 0.35 A output.

Keywords

AC-DC power convertors; driver circuits; light emitting diodes; power factor correction; LED current; LED driver; current 0.35 A; electrolytic capacitor-less AC-DC drivers; input power factor; optimum injected current harmonics; peak-to-average ratio; voltage 25 V; Capacitors; Driver circuits; Harmonic analysis; Light emitting diodes; Peak to average power ratio; Power harmonic filters; Turning; Flyback converter; harmonic current injection; light-emitting diode (LED); peak-to-average ratio; power factor correction (PFC);

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/TPEL.2010.2098482

Filename

5664804