90 research outputs found
Multiobjective optimisation of hybrid wind-PV-battery-fuel cell-electrolyser-diesel systems : An integrated configuration-size formulation approach
Acknowledgment The financial support by Energy Renewable UK Ltd through co-funding of REST4U project is gratefully acknowledged.Peer reviewedPostprin
Evolutionary Dynamic Multi-Objective Optimisation : A survey
Peer reviewedPostprin
Access point deployment optimisation in communication-based train control systems
Through the use of new communication-based train control (CBTC) systems, modern metro railways have been able to provide a more efficient, more reliable and more eco-friendly transport services. The main advantages of the CBTC systems are achieved by utilising modern communication technologies. The performance of the communications network is dependent on a well-designed access point (AP) deployment, as this determines the overall communication capability and impacts the cost. In this thesis, a systematic methodology is proposed for formulating and solving AP deployment planning (ADP) problems in two scenarios: (i) a tunnel section area; and (ii) a real-world metro system. Different mathematical models are presented for modelling the ADP problem in these two scenarios. In addition to mathematical models, an exhaustive search and a customized search algorithm, which uses a multi-objective evolutionary algorithm based on decomposition (MOEA/D), are proposed for solving the ADP optimisation problems. The methodologies are applied to the scenarios mentioned above. To evaluate the optimisation results, the optimised AP deployments are tested on a simulation platform integrating a railway network simulator and a communication network simulator. The test result shows that with the optimised AP deployments the DCS can achieve a better performance while using fewer APs
ENERGY EFFICIENT WIRED NETWORKING
This research proposes a new dynamic energy management framework for a backbone Internet Protocol over Dense Wavelength Division Multiplexing (IP over DWDM) network. Maintaining the logical IP-layer topology is a key constraint of our architecture whilst saving energy by infrastructure sleeping and virtual router migration.
The traffic demand in a Tier 2/3 network typically has a regular diurnal pattern based on people‟s activities, which is high in working hours and much lighter during hours associated with sleep. When the traffic demand is light, virtual router instances can be consolidated to a smaller set of physical platforms and the unneeded physical platforms can be put to sleep to save energy. As the traffic demand increases the sleeping physical platforms can be re-awoken in order to host virtual router instances and so maintain quality of service.
Since the IP-layer topology remains unchanged throughout virtual router migration in our framework, there is no network disruption or discontinuities when the physical platforms enter or leave hibernation. However, this migration places extra demands on the optical layer as additional connections are needed to preserve the logical IP-layer topology whilst forwarding traffic to the new virtual router location. Consequently, dynamic optical connection management is needed for the new framework.
Two important issues are considered in the framework, i.e. when to trigger the virtual router migration and where to move virtual router instances to? For the first issue, a reactive mechanism is used to trigger the virtual router migration by monitoring the network state. Then, a new evolutionary-based algorithm called VRM_MOEA is proposed for solving the destination physical platform selection problem, which chooses the appropriate location of virtual router instances as traffic demand varies. A novel hybrid simulation platform is developed to measure the performance of new framework, which is able to capture the functionality of the optical layer, the IP layer data-path and the IP/optical control plane. Simulation results show that the performance of network energy saving depends on many factors, such as network topology, quiet and busy thresholds, and traffic load; however, savings of around 30% are possible with typical medium-sized network topologies
Computational intelligence techniques for energy storage management
Ph. D. ThesisThe proliferation of stochastic renewable energy sources (RES) such as photovoltaic
and wind power in the power system has made the balancing of generation and demand
challenging for the grid operators. This is further compounded with the liberalization
of electricity market and the introduction of real-time electricity pricing (RTP) to
reflect the dynamics in generation and demand. Energy storage sources (ESS) are
widely seen as one of the keys enabling technology to mitigate this problem. Since ESS
is a costly and energy-limited resource, it is economical to provide multiple services
using a single ESS. This thesis aims to investigate the operation of a single ESS in a
grid-connected microgrid with RES under RTP to provide multiple services.
First, artificial neural network is proposed for day-ahead forecasting of the RES,
demand and RTP. After the day-ahead forecast is obtained, the day-ahead schedule of
energy storage is formulated into a mixed-integer linear programming and implemented
in AMPL and solved using CPLEX. This method considers the impact of forecasting
errors in the day-ahead scheduling. Empirical evidence shows that the proposed nearoptimal
day-ahead scheduling of ESS can achieve a lower operating cost and peak
demand.
Second, a fuzzy logic-based energy management system (FEMS) for a grid-connected
microgrid with RES and ESS is proposed. The objectives of the FEMS are energy
arbitrage and peak shaving for the microgrid. These objectives are achieved by
controlling the charge and discharge rate of the ESS based on the state-of-charge (SoC)
of ESS, the power difference between RES and demand, and RTP. Instead of using a
forecasting-based approach, the proposed FEMS is designed with the historical data
of the microgrid. It determines the charge and discharge rate of the ESS in a rolling
horizon. A comparison with other controllers with the same objectives shows that the
proposed controller can operate at a lower cost and reduce the peak demand of the
microgrid.
Finally, the effectiveness of the FEMS greatly depends on the membership functions.
The fuzzy membership functions of the FEMS are optimized offline using a Pareto based multi-objective evolutionary algorithm, nondominated sorting genetic algorithm-
II (NSGA-II). The best compromise solution is selected as the final solution and
implemented in the fuzzy logic controller. A comparison was made against other
control strategies with similar objectives are carried out at a simulation level. Empirical
evidence shows that the proposed methodology can find more solutions on the Pareto
front in a single run. The proposed FEMS is experimentally validated on a real
microgrid in the energy storage test bed at Newcastle University, UK. Furthermore,
reserve service is added on top of energy arbitrage and peak shaving to the energy
management system (EMS). As such multi-service of a single ESS which benefit the
grid operator and consumer is achieved
Numerical and Evolutionary Optimization 2020
This book was established after the 8th International Workshop on Numerical and Evolutionary Optimization (NEO), representing a collection of papers on the intersection of the two research areas covered at this workshop: numerical optimization and evolutionary search techniques. While focusing on the design of fast and reliable methods lying across these two paradigms, the resulting techniques are strongly applicable to a broad class of real-world problems, such as pattern recognition, routing, energy, lines of production, prediction, and modeling, among others. This volume is intended to serve as a useful reference for mathematicians, engineers, and computer scientists to explore current issues and solutions emerging from these mathematical and computational methods and their applications
Innovative Wireless Localization Techniques and Applications
Innovative methodologies for the wireless localization of users and related applications
are addressed in this thesis.
In last years, the widespread diffusion of pervasive wireless communication
(e.g., Wi-Fi) and global localization services (e.g., GPS) has boosted the interest
and the research on location information and services. Location-aware
applications are becoming fundamental to a growing number of consumers (e.g.,
navigation, advertising, seamless user interaction with smart places), private and
public institutions in the fields of energy efficiency, security, safety,
fleet management, emergency response. In this context, the position of the user - where
is often more valuable for deploying services of interest than the identity of the
user itself - who.
In detail, opportunistic approaches based on the analysis of electromagnetic
field indicators (i.e., received signal strength and channel state information) for
the presence detection, the localization, the tracking and the posture recognition
of cooperative and non-cooperative (device-free) users in indoor environments are
proposed and validated in real world test sites. The methodologies are designed
to exploit existing wireless infrastructures and commodity devices without any
hardware modification.
In outdoor environments, global positioning technologies are already available
in commodity devices and vehicles, the research and knowledge transfer
activities are actually focused on the design and validation of algorithms and
systems devoted to support decision makers and operators for increasing efficiency,
operations security, and management of large fleets as well as localized
sensed information in order to gain situation awareness. In this field, a decision
support system for emergency response and Civil Defense assets management
(i.e., personnel and vehicles equipped with TETRA mobile radio) is described in
terms of architecture and results of two-years of experimental validation
Optimisation, Optimal Control and Nonlinear Dynamics in Electrical Power, Energy Storage and Renewable Energy Systems
The electrical power system is undergoing a revolution enabled by advances in telecommunications, computer hardware and software, measurement, metering systems, IoT, and power electronics. Furthermore, the increasing integration of intermittent renewable energy sources, energy storage devices, and electric vehicles and the drive for energy efficiency have pushed power systems to modernise and adopt new technologies. The resulting smart grid is characterised, in part, by a bi-directional flow of energy and information. The evolution of the power grid, as well as its interconnection with energy storage systems and renewable energy sources, has created new opportunities for optimising not only their techno-economic aspects at the planning stages but also their control and operation. However, new challenges emerge in the optimization of these systems due to their complexity and nonlinear dynamic behaviour as well as the uncertainties involved.This volume is a selection of 20 papers carefully made by the editors from the MDPI topic “Optimisation, Optimal Control and Nonlinear Dynamics in Electrical Power, Energy Storage and Renewable Energy Systems”, which was closed in April 2022. The selected papers address the above challenges and exemplify the significant benefits that optimisation and nonlinear control techniques can bring to modern power and energy systems
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