Study the effect of series and parallel LEDs connections on the output current ripple for LED driver of solar street lighting

LED lighting fixtures become very important and largely used to replace the conventional sodium and metal-halide lighting fixtures used to illuminate streets. LED lighting fixture consists of group of high brightness LEDs lenses arranged in specific configuration and energized from power source via LED driver, the power source in this research is considered batteries storage system charged from micro-generation PV system at the daylight hours. Then, the required LED driver is a current controlled DC-DC converter. This paper studies the effect of series, parallel and hybrid connections for LEDs' array on the equivalent dynamic resistance that is inversely proportional to the output LED current ripple. It is very important to connect the LEDs array of street lighting fixtures in suitable connection to draw low current ripple. Lower output current ripples guide to minimize the size of the electrolytic capacitor, then increasing the LEDs life timer.