Dual-mode power regulator for photovoltaic module emulation

Photovoltaic (PV) module emulators, which can provide reproducible and controllable input power profile for a load device corresponding to different ambient conditions for a PV module, can significantly reduce the level of effort and cost for the development and optimization of the PV module, load devices, as well as interfacing power converters. In this paper, we introduce a dual-mode power regulator for the PV emulation. The dual-mode regulator consists of a voltage regulator and a current regulator, connected by two diodes for power hybridization. The circuit switches between the two regulators in order to accurately emulate the electrical output behavior of a PV module under different ambient conditions (e.g., solar irradiance, temperature) and load demands. The proposed regulator circuit provides accurate emulation results over the full operating range of the PV module by complementary use of the two regulators. We develop a robust control method for producing an accurate I-V curve with compensation of the loss in the circuit components. We validate the behavior of the proposed circuit and control method by Matlab/Simulink simulations and experiments. The experimental results shows that the PV emulation output is greatly improved with the proposed dual-mode regulator. (C) 2012 Elsevier Ltd. All rights reserved.