Optimal Energy Management and MPC Strategies for Electrified RTG Cranes with Energy Storage Systems

Feras Alasali,Victor Becerra,Stephen Haben,William Holderbaum

doi:10.3390/en10101598

Abstract

This article presents a study of optimal control strategies for an energy storage system connected to a network of electrified Rubber Tyre Gantry (RTG) cranes. The study aims to design optimal control strategies for the power flows associated with the energy storage device, considering the highly volatile nature of RTG crane demand and difficulties in prediction. Deterministic optimal energy management controller and a Model Predictive Controller (MPC) are proposed as potentially suitable approaches to minimise the electric energy costs associated with the real-time electricity price and maximise the peak demand reduction, under given energy storage system parameters and network specifications. A specific case study is presented in to test the proposed optimal strategies and compares them to a set-point controller. The proposed models used in the study are validated using data collected from an instrumented RTG crane at the Port of Felixstowe, UK and are compared to a standard set-point controller. The results of the proposed control strategies show a significant reduction in the potential electricity costs and peak power demand from the RTG cranes.

Highlights

An Energy Storage System (ESS) is a significant tool for a more energy efficient ecosystem and help to decrease environmental concerns [1,2]
This paper presents control algorithms using real-time data collected from electrified Rubber Tyre Gantry (RTG) cranes at the Port of Felixstowe, UK, to control the energy storage system located at the substation side of RTG crane network systems
The proposed Model Predictive Control (MPC) and optimal management controller in this work was applied to an electrified RTG crane system model equipped with an ESS located at the low voltage side of the substation

Summary

Introduction

An Energy Storage System (ESS) is a significant tool for a more energy efficient ecosystem and help to decrease environmental concerns [1,2]. The objective of an ESS is to reduce the cost of electricity and avoid the need to upgrade the distribution network by shifting energy consumption from peak to valley periods [2]. Sea ports are moving towards replacing diesel RTG cranes [3,4], which move containers on a port platform and organise container storage in the yard area, with electric. RTG cranes to reduce green gas emissions and improve energy efficiency [1,2,3]. In RTG crane system, most of electricity energy or fuel consumption comes from hoisting containers with different weights to several heights. The peak demand increases when the RTG crane moves heavier containers [5]. The shift to the use of electrified RTG cranes can reduce the costs for equipment repairs and maintenance by around 30%

Objectives

Results

Conclusion