Optimized controller for renewable energy sources integration into microgrid: Functions, constraints and suggestions

The generation and integration of renewable energy sources (RESs) into microgrid (MG) systems have recently demonstrated a significant increase due to the capability of RESs to meet the rising power demands and reduce environmental pollution. However, the fast expansion of MGs and their complex structures due to the wide integration area of distributed RESs and their intermittent behaviour may affect the power system stability and security. Thus, a properly optimised control method is important to guarantee an efficient, secure and high-quality power transfer. This paper highlights a comprehensive study of optimised controller approaches concerning the RES integration into MGs and their classification in terms of structure, characteristics, operation, constraints, functions, cost, pros and cons. This study focuses on the advanced and conventional optimisation algorithms used in MG applications. The rigorous review shows that current control optimisation strategies can enhance the operation and integration of RESs into MGs. However, further improvement of control optimisation is required to achieve sustainable energy operation and renewables integration in the future. The majority of the existing methods is restricted to simulation analysis; consequently, experimental validation is necessary. The standard requirements concerning the integration of RESs into MGs and their possible improvement and harmonisation are highlighted. This study also focuses on different issues, challenges and constraints related to the integration and control optimisation of RESs as well as recommendations for future research. Overall, this review will hopefully strengthen the efforts towards the development of a reliable renewable integration using efficient optimisation algorithms for future applications. (C) 2020 Elsevier Ltd. All rights reserved.