Stochastic Optimal Control Scheme for Operation Cost Management in Energy Internet

Abstract

By integrating power flows and information bi-directly, energy Internet (EI) is regarded as an internet style solution for energy issues, and it has been considered as a promising architecture for the future energy systems. In this paper, we consider the optimal operation cost management problem for a generalized EI topology which is composed of multiple interconnected AC microgrids (MGs) and energy routers (ERs). We assume that all the MGs are composed of wind turbine generators (WTGs), photovoltaic (PV) units, fuel cells (FCs), micro turbines (MTs), battery energy storage (BES) devices, and loads. Multiple topologies of EI are discussed and a generalized one is studied for mathematical system modelling. A group of ordinary differential equations (ODEs) and stochastic differential equations (SDEs) are utilized to describe the dynamics of each component within the whole EI. The controllers are set in MTs, FCs and ERs. We consider the operation cost of EI as a combination of four parts: the cost of BES devices, the power transmission loss between the interconnected MGs, the risk from AC bus frequency deviation and the additional cost involved by the controllers. Then the cost optimization problem is formulated as a stochastic control problem which is solved numerically. The effectiveness of the obtained optimal controllers is illustrated through numerical simulations.