Microgrid Robust Planning Model and Its Modification Strategy Based on Improved Grey Relational Theory

Abstract

A two-stage robust planning model is constructed in this paper, which can reduce the joint planning uncertainty of a wind-photovoltaic-energy storage system caused by the stochastic characteristics of renewable energy and ensure the sustainability of the power grid. Considering the life loss of energy storage system comprehensively, the joint planning is realized in the worst scenario. Addressing the problem that subjective and uniform robustness parameters in robust optimization cannot cope with the differentiated characteristics of each uncertainty, a robust microgrid-planning model and its modification strategy based on improved grey relational theory are proposed. The idea of weight distribution and dynamic value of identification coefficients are introduced into grey relational theory, so as to enhance the weight of indicators that influence planning and the relational degree between them, which can avoid the locally relational tendency. According to the relation degree, the renewable energy’s robustness parameters are modified to improve the applicability and flexibility of the microgrid-planning results. Finally, the effectiveness and superiority of the proposed theory and method are verified using a case study approach.