Resilient expansion planning of virtual power plant with an integrated energy system considering reliability criteria of lines and towers

Abstract

The portfolio of virtual power plants (VPP) is a flexible system for facilitating a wide range of resources with wide geographical coverage. A VPP can be placed at the intersection of electric power and energy systems by adding heat pumps to the portfolio, thereby accelerating the formation of integrated energy systems. VPPs, while virtual, still rely on a physical network for operations. The power transmission network has the responsibility of ensuring the security of supply, reliability of operation, and optimal planning for expansion. A vast majority of power network infrastructures, such as lines and towers, were installed in the last century, thus the existing infrastructure with aging components is not homogeneous. The transmission network covers a large geographical area which is expensive to maintain and requires large investments to avoid congestion. This work addresses the research question of how the condition of the existing network infrastructure affects the potential plans to expand the network. The condition of network infrastructure refers to the health of each line and tower. The decision of expansion includes both expansion with dismantling (restructuring) and without (reconfiguration) dismantling the existing lines and towers. The condition of the power network is determined by the maintenance cost of lines as well as a health index with associated risk factors of the tower. The investigation covers a range of cases where we research how the investment decisions change with the option of installing heat pumps in order to meet heating demand locally, and also when the condition of the network (health of lines and towers) is factored in, while also adding in the level of risk associated with each tower. Beyond the cases, extensive sensitivity analyses are conducted to evaluate the trade-offs between decision variables, such as cost of heat pump, coefficient of performance of heat pump, risk factors, and line and tower costs. The results of this work lay the foundation for understanding how the condition of network infrastructure impacts optimal decisions for expansion.