PV grid-connected power conditioning system with Z-source network

This paper presents a single-phase photovoltaic power conditioning system (PVPC) based on a Z-source impedance network instead of a conventional boost converter. Using Z-source networks, the system can work within a wider range of PV array output voltages than for a conventional boost converter. Single phase instantaneous reactive power theory is adopted for harmonics current detection and a synthesis algorithm combining harmonic components with the PV active power component is used to produce reference compensation signals. The whole system is modeled and simulated in a Matlab/Simmulink environment. Simulation results demonstrate that the PVPC system with Z-source network can perform maximum power point tracking (MPPT) and voltage boosting when needed to interface with the utility grid. In addition, it can deliver valuable functions such as harmonics suppression and reactive power compensation.