A review on the implementation of nonlinear source emulators

Renewable energy sources are playing an important role in industry as green sources of energy to reduce carbon dioxide emissions. They possess electrically nonlinear voltage-current characteristics. In the test and development of the downstream converters that utilize these renewable types of energy, the practice of using nonlinear source emulators instead of the real nonlinear sources has gained a lot of interest. Different methods of implementing nonlinear source emulators have been reported in the literature, but no paper exists reviewing and assessing them from different technical points of view. This paper provides a review of the implementation of existing nonlinear source emulators. Their configurations are redrawn as block diagrams and their circuit operations are discussed. Different industrial emulators are also briefly reviewed concerning their features.