Incorporating flexibility requirements into distribution system expansion planning studies based on regulatory policies

Abstract

Increasing penetration of renewable energy sources with intermittent generation calls for further flexibility requirements for efficient as well as the safe operation of power systems. Considering the significant growth of distributed energy resources in distribution systems, a promising approach to fulfill such requirements is to deploy local flexibility sources at the distribution level. Nonetheless, due to the monopoly nature of electricity distribution business, effective regulations are required to direct distribution companies toward fulfilling such goals. Accordingly, this paper aims at proposing various policies to motivate distribution companies to enhance the flexibility of their networks. In order to assess the effectiveness of these rules, we present a novel multi-stage distribution expansion planning model considering flexibility requirements. In this model, installation of conventional dispatchable distributed generation units and battery energy storage systems, as well as demand response programs, are considered available flexibility sources for distribution system planners. The proposed framework is applied to a test distribution network with 18 nodes, and the obtained results are thoroughly discussed. Finally, a sensitivity analysis is conducted to assess the effects of the key parameters of the proposed model on expansion planning of the test system.