Optimal economic dispatch for renewable energy microgrids with hybrid storage using Model Predictive Control

Abstract

The transition from the current power system to a renewable energy-based smart grid will require of smaller units for managing the random aspects between the generation sources and load demand. The introduction of energy storage systems inside microgrids brings the opportunity to decide the optimal moment to purchase or sale energy to the grid. The use of different energy storage systems gives the chance to take the advantages of each system minimizing the disadvantages.In this paper a long term scheduling optimization of a gridconnected renewable energy microgrid (μG) with hybrid energy storage is designed and evaluated. Management is performed using Model Predictive Control (MPC) to maximize the economical benefit of the microgrid while minimizing the use cost of each storage system. Several concepts as lifetime cost, degradation cost, start up/off cost and operation and maintenance (o&m) cost of the hybrid energy storage system are included. In order to model both continuous/discrete dynamics and switching between different operating conditions, the plant is modeled with the framework of Mixed Logic Dynamic (MLD). Taking into account the presence of integer variables the MPC problem is solved as MIQP (Mixed Integer Quadratic Programming).