Optimal Real-Time Scheduling for Hybrid Energy Storage Systems and Wind Farms Based on Model Predictive Control

Meng Xiong,Siyun Chen,Feng Gao,Jiaojiao Dong,Kun Liu

doi:10.3390/en8088020

Meng Xiong, Siyun Chen + Show 3 more

Open Access

https://doi.org/10.3390/en8088020

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Journal: Energies	Publication Date: Aug 3, 2015
Citations: 51	License type: CC BY 4.0

Affiliation: Xi'an Jiaotong University

Abstract

Energy storage devices are expected to be more frequently implemented in wind farms in near future. In this paper, both pumped hydro and fly wheel storage systems are used to assist a wind farm to smooth the power fluctuations. Due to the significant difference in the response speeds of the two storages types, the wind farm coordination with two types of energy storage is a problem. This paper presents two methods for the coordination problem: a two-level hierarchical model predictive control (MPC) method and a single-level MPC method. In the single-level MPC method, only one MPC controller coordinates the wind farm and the two storage systems to follow the grid scheduling. Alternatively, in the two-level MPC method, two MPC controllers are used to coordinate the wind farm and the two storage systems. The structure of two level MPC consists of outer level and inner level MPC. They run alternatively to perform real-time scheduling and then stop, thus obtaining long-term scheduling results and sending some results to the inner level as input. The single-level MPC method performs both long- and short-term scheduling tasks in each interval. The simulation results show that the methods proposed can improve the utilization of wind power and reduce wind power spillage. In addition, the single-level MPC and the two-level MPC are not interchangeable. The single-level MPC has the advantage of following the grid schedule while the two-level MPC can reduce the optimization time by 60%.

Highlights

With the increasing penetration of wind energy into power grids, the negative influences of wind farms are non-negligible [1,2]
Energy storage systems can be classified as fast response or slow response depending on the response time [12]
The purpose of this paper is to present two model predictive control (MPC) models to be implemented in wind farms with hybrid storage systems including a pumped hydro storage system and a fly wheel system

Summary

Introduction

With the increasing penetration of wind energy into power grids, the negative influences of wind farms are non-negligible [1,2]. Energy storage systems have been verified to be an effective method for overcoming these deficiencies [5,6,7]. The system that coordinates a wind farm with energy storage systems can be dispatched into power grids, which is similar to that of a conventional energy plant [8]. Energy storage systems can be classified into two general categories: high power density and high energy density types [9,10,11]. Energy storage systems can be classified as fast response or slow response depending on the response time [12]

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Conclusion