An expansion planning approach for AC-DC distribution systems considering risk and reliability simultaneously

Abstract

In the modern era, rapid changes in energy demand, emerging technologies, and environmental concerns have made research on AC-DC distribution systems increasingly significant. The growing integration of renewable energy sources and electric vehicles (EVs) necessitates a highly reliable AC-DC distribution system to ensure an uninterrupted energy supply. Additionally, uncertainties in load demand and renewable power generation underscore the need for effective risk management. This paper presents a fully dynamic approach to AC-DC distribution system expansion planning, simultaneously considering risk and reliability. Risk management in distribution network planning varies between risk-averse and risk-seeking perspectives, directly influencing the application of the conditional value at risk (CVaR) metric. Security constraints, including bus voltage and line loading limits, are categorized as hard and soft constraints. Hard constraints must always be satisfied, whereas violations of soft constraints are penalized through additional costs. The objective function comprises investment and operational costs, along with the CVaR metric, which determines bus type, line type, conductor type in each line, and system topology over time. The proposed approach is applied to a test system in various cases, and the results are analyzed and discussed.