Active and Reactive Power Sharing for PV Power Plants with Quasi-Z-source Cascaded H-bridge Multilevel Inverters

Quasi-Z-source cascaded H-bridge multilevel inverters (qZS-CHBMLIs) have gained interest in photovoltaic (PV) applications, where each module allows single-stage power conversion of a PV power plant controlling the DC voltage independently to operate each PV generator at maximum or limited power, and thus reducing the number of modules needed. This paper presents a control system to share the active and reactive power in PV plants with qZS-CHBMLIs operating with different conditions and limited power delivered to the grid. It is applied to a grid-connected qZS-CHBMLI with three cascaded qZSI, each one connected to a 4.8 kW PV power plant. The control system is evaluated under different operating conditions in each PV power plant, and delivering to the grid the available power or limiting it according to the active and reactive power setpoint defined by the system operator. The results show the adequate response of the proposed configuration and the control system.