Multi-Time Scale Economic Scheduling Method Based on Day-Ahead Robust Optimization and Intraday MPC Rolling Optimization for Microgrid

Jing Zhang,Xiaofan Fu,Heng Zhang,Dian Qin,Yongchun Ye,Jing Yang,Yu He,Guoyi Shi

doi:10.1109/access.2021.3118716

Abstract

Due to the source and load prediction errors and uncertainties, the real operation state of microgrid may deviate significantly from the expected state, which leads to prevent the system from reaching its expected economic effects. In order to obtain the optimal economic effects for microgrid scheduling, an optimal microgrid scheduling model considered the demand responses is built in this paper firstly, and then a multi-time scale economic scheduling method based on day-ahead robust optimization and intraday model predictive control (MPC), is developed as well. Moreover, in the day-ahead stage, the long-time scale interval is set as 1 h and the robust optimization is used to address the low-frequency components in prediction errors and uncertainties. Meanwhile, the robust optimization enables to gain the day-head optimal economic scheduling plan for the microgrid and to keep the system operating effectively even when large-scale fluctuations happen. Furthermore, in the intraday stage, the short-time scale interval is set as 15 mins and MPC is adopted to track and correct the day-ahead economic scheduling plan, which enables to address the high-frequency components in prediction errors and uncertainties. Finally, simulation results demonstrate the feasibility of the proposed optimal microgrid scheduling model and the validity of the proposed multi-time scale economic scheduling method.

Highlights

Nowadays energy crisis calls for innovative sources and techniques for effectively utilizing more renewable energies such as wind energy and solar energy
The main contribution of this research is that we propose a multi-time scale economic scheduling method based on day-ahead robust optimization and intraday model predictive control (MPC) rolling optimization for microgrid, the microgrid can obtain better economy in the real operation state through this method
Prediction errors and uncertainties of source and load cause the real operating state of a microgrid to fluctuate over a wide range

Summary

INTRODUCTION

Nowadays energy crisis calls for innovative sources and techniques for effectively utilizing more renewable energies such as wind energy and solar energy. The research on the microgrid economic scheduling plan mostly focuses on the day-ahead and intraday multi-time scale optimal scheduling model to address the uncertainties. C. THE PROPOSED METHOD To ensure the economy and the stability of microgrid in the real operation state, this paper refers to the related studies reported and combines with the features of the robust optimization and the MPC rolling optimization, proposes a multi-time scale economic scheduling method for microgrid. In the day-ahead and long-time scale scheduling stage, a robust economic optimization model is established to minimize the whole day operation cost and consider the demand response. The main contribution of this research is that we propose a multi-time scale economic scheduling method based on day-ahead robust optimization and intraday MPC rolling optimization for microgrid, the microgrid can obtain better economy in the real operation state through this method. By optimizing and scheduling the controllable units of the microgrid at different time scales, the economy of microgrid operation is ensured

DAY-AHEAD LONG-TIME SCALE SCHEDULING WITH ROBUST OPTIMIZATION

INTRADAY SHORT-TIME SCALE SCHEDULING WITH MODEL PREDICTIVE CONTROL

MULTI-TIME SCALE OPTIMAL MICROGRID SCHEDULING PROCESS

CONCLUSION