Solar PV charge controller and an efficient SPRL MOSFET based sine symmetrical inverter for compact fluorescent lamp

Use of compact fluorescent lamps (CFL) is on the increase for photovoltaic lighting systems due to their high luminous efficacy and ability to provide adequate lumen output for a given lighting application. The luminous efficacy increases with switching frequency while providing eye comfort to the user. The low electrical consumption makes the CFL an ideal choice for photovoltaic power systems for lighting applications. However the CFL's electrical requirements are not easily met by hard switched inverters due to their higher switching losses at higher frequencies and the difficulty in meeting the complex electrical requirements of CFL of preheat and ignition voltage, resulting in lower efficiency. A series parallel resonant mode sine wave inverter is discussed which provides the basic electrical characteristics requirements of CFL, protection needs for higher reliability while offering higher inverter efficiency and above all a fairly constant lumen output throughout the operating DC voltage range by a unique control scheme. A series interrupting-type charge controller makes the PV power system self-sufficient for producing light in remote areas while maintaining reliability.