A family of isolated integrated drivers with reduced capacitors for light system based on power LEDs

This paper presents a family of isolated electronic systems to supply power light emitting diodes (LEDs) for street lighting system applications. These systems are analyzed aiming to reduce the capacitances of de circuit, to eliminate electrolytic capacitors or replace them for film capacitors. The film capacitors were chosen due to their long lifetime, compatible with LEDs lifetime. This is possible through control techniques applications, keeping an appropriate relationship between input current distortion and the acceptable ripple of the output current. The integration of the power system stages is made to increase the system reliability by reducing the number of controlled switches. The systems were designed to supply 32 power LEDs connected in series and supplied with 700 mA, resulting in 70 W. The systems aim to high power factor and low total harmonic distortion (THD) of the input current, according to the IEC 61000-3-2 standard.