Optimal Configuration of Long- and Short-Term Energy Storage in Microgrid with Multi-Timescale Power and Energy Balances

Renewable energy exhibits significant fluctuations with multi-time scales, including long-term fluctuations and short-term intra-day fluctuations. To mitigate these fluctuations, this study proposes an optimal configuration method for long- and short-term energy storage in microgrid with multi-timescale power and energy balances. First, the daily power balance with hourly operation and the annual energy balance with daily operation models are modeled. Then, a two-stage optimal planning model is developed for the microgrids with long- and short-term energy storage, where the first stage optimizes the energy capacity of long-term energy storage, and the second stage configures the power capacity of long-term energy storage and the capacity of short-term energy storage. Furthermore, an improved Benders decomposition algorithm is used to address high-dimensional computational challenges. Case studies verify that the proposed method can optimize energy storage configuration at an 8760-hour scale. The decoupled configuration significantly reduces system costs, demonstrating both effectiveness and economic efficiency.