Stochastic Optimal Control Scheme for Battery Lifetime Extension in Islanded Microgrid via a Novel Modeling Approach

Abstract

Most of the existing literature concerning lifetime extension of battery energy storage (BES) devices mainly focus on designing controllers in BES devices themselves. In this paper, the problem of BES lifetime extension in an islanded microgrid is considered from a different perspective, in the sense that such target is achieved by adjusting output power of controllable power generation devices. To obtain accurate power models of photovoltaic panels and loads, a new hybrid modeling method utilizing both neural networks and stochastic differential equations is proposed. We formulate the problem of extending the service life of BES devices as a stochastic optimal control problem. Meanwhile, the situation of over-control in micro-turbines is effectively avoided. We solve such stochastic optimization problem using the dynamic programming solver provided by the open source C++ program BOCOPHJB. Finally, the obtained optimal controller is verified with simulations.