Comparison of Controllable Photovoltaic Emulation Methods for Real-Time Hardware Experiments

Abstract

Emulating photovoltaic (PV) modules in a controllable lab environment to interface with power electronics hardware is challenging but vital as it enables more realistic experiments to be conducted in real-time. However, the emulation methods often require nonlinear PV modeling, which may have long computational times. Hence, an effective real-time emulation method should minimize the computation time while maintaining high accuracy. This work compares different PV emulation techniques to investigate the advantages and disadvantages of various methods for real-time hardware testing. First, a literature survey compares the type of PV model, interface used, controller, and real-time technique adopted to emulate a PV model’s current-voltage characteristics. Then, the PV model emulation methods are compared using a low-cost real-time emulator (RT Box 1), and computational cycle times are measured. The target application is to emulate a PV panel over various days and test the system control algorithm in real time for a PV microinverter with an integrated battery.