Abstract:

In this study, a disturbance observer-based power control system is developed for voltage source converters (VSC) to achieve smooth power delivery to the grid. Firstly, modeling of grid connected converter which is used for power delivery in terms of frequency and current dynamics is executed under consideration of modelling errors and uncertainties. This disturbance effects are mainly consist of frequency and amplitude variations, output impedance aging, large dc-link voltage ripple A second order nonlinear observer is integrated into the designed control to reject with model uncertainty and disturbances. Due to the objective of the proposed controller is power regulation, there is no need a voltage and current compensator. Comperative simulations are carried out to verify the robustness of the proposed controller. Also effectiveness of the proposed approach is tested under different grid scenarios (e.g., weak grid, dc-link variation, frequency deviation)

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