A multi-function photovoltaic power supply system with grid-connection and power factor correction features

A conventional photovoltaic (PV) inverter system with grid-connection feature is usually composed of a full-bridge inverter and a microprocessor. The PV system is idle when there is no insolation (at nighttime). To optimize the use of the existing components, this paper proposes a multi-function PV power supply system with grid-connection, power factor correction and lamp-driving features. With the synchronous switch technique, pulse-width modulation, additional relays and components, an ordinary inverter system can function alternately as an electronic ballast with power factor correction at nighttime. Thus, the power switches, driving circuits and the microprocessor in such a multi-function system are optimally used. Computer simulation results and experimental measurements have verified the feasibility of the proposed system.