Design and Implementation of Decentralized Control for Distributed generation based Off-grid System

In this paper decentralized control for distributed generation based off-grid system to realize a save and optimal operation under perturbation problems, is presented. However, perturbation and observation (P&O) technique is reinforced by iterative interpolation method to realize accurate and fast convergence toward the maximum global operating point without speed information. Furthermore, enhanced indirect control is developed to operate the solar photovoltaic system (SPVS) without any MPPT technique. To achieve high performance during the transition, as well as to mitigate the 5th and 7th order-harmonics, a simple robust control, is employed, where the AC source current is estimated using the generated and consumed power in the system. Optimal gain design of the AWPI and AWPRC controllers are given. The behavior of the developed concept for the distributed generation based off-grid system is tested under presence of several conditions.