A DC/DC converter with active filter capabilities for residential PV generators

In residential applications grid-connected Photo Voltaic (PV) generators are generally connected to single phase AC grids. In these cases a periodical power unbalance is generated because the power drawn by the grid features a large ripple at twice the fundamental frequency, while PV modules generate a DC power. Such a power unbalance affects the Maximum Power Point Tracking (MPPT) forcing the system to operate under suboptimal conditions. In this paper a new approach is presented dealing with the realization of an active filter inside the DC/DC step up converter, without the introduction of extra power devices. According to the proposed approach the size of the electrolytic capacitor bank can be largely reduced, thus improving the reliability, while lowering costs and size.