A novel inverter scheme for Photovoltaic applications with reduced DC-link capacitor

A power topology based on high frequency switched DC-DC converter, reduced DC-link capacitor and three-phase inverter for providing isolated ac power is presented in this paper. The use of small DC-link capacitor increases the lifetime of the converter and reduces its size. Selective Harmonic Elimination is used to switch the devices for obtaining harmonic reduction while maintaining low switching frequency. Dutycycle variation of a pulsating DC bus is used to vary the fundamental amplitude. This leads to better utilisation of device voltage ratings for the same DC bus peak voltage. The design of a damped filter required to eliminate the higher order harmonics is also discussed. Simulation results illustrate that the topology can lead to a good quality output and flexible control performance.