A Novel Quasi-Z Source Cascaded Multilevel Photovoltaic Power System Applied to Smart Microgrid

A novel Quasi-Z source (QZS) cascaded multilevel inverter (CMI) (QZS-CMI) based photovoltaic (PV) power system applied to smart microgrid is proposed in this paper. The novel QZS impedance network has strong boost ability. Each PV panel connects to a QZS inverter (QZSI) to form a power generation module. By establishing an analytical model of each QZSI module to design reasonable parameters of the novel QZS impedance network, it can limit the second-harmonic (2) ripples. Each QZSI module has an independent DC-link peak voltage control with phase-shifted pulse-width-amplitude modulation (PS-PWAM), so the novel QZS-CMI’s power loss is reduced. The simulation results verify the feasibility of the control strategy. The proposed novel QZS-CMI provides an effective method for the realization of new energy generation.