Photovoltaic Power Conversion System Based on Cascaded Inverters with Synchronized Space-Vector Modulation

Abstract. The paper presents results of investigation of dual-inverter-bases power conversion system with synchronized pulsewidth modulation (PWM) for photovoltaic application. This system topology includes two insulated strings of photovoltaic panels, feeding two standard three-phase inverters, connected to grid by a three-phase transformer with the open winding configuration on primary side. Algorithms of synchronized PWM provide in this case continuous voltage synchronization both in each inverter and in the load. Simulations show a behavior of the systems with low switching frequency, with both continuous and discontinuous versions of synchronized PWM. Key words Cascaded two-level inverters, photovoltaic application, modulation strategy, voltage synchronization. 1