Modeling and design of a flexible solar array simulator topology

Photovoltaic (PV) systems have gained prominence in the context of distributed generation systems. The fundamental element of a PV grid-connected systems is the power converter. Before marketed power converters must be tested and certified according to the international standards. Therefore, a flexible equipment to test the converters is necessary. This paper presents the modeling and control structure of a solar array simulator (SAS) of 10 kW for testing inverters for photovoltaic applications. The limitations of conventional structures are pointed out and an improved structure based on two converter stages is proposed. The feasibility of the proposed SAS is shown through simulations using Matlab/Simulink package and experimental results. The simulator is tested for the system connected to resistive loads and to a photovoltaic converter model. The dynamical behavior is evaluated through solar irradiance variations and partial shadowing tests. Results showed that the proposed structures presents high capacity to simulate different shapes of solar irradiance, besides allow flexible configuration of the irradiance profile.