3,259 research outputs found
Smart Procurement of Naturally Generated Energy (SPONGE) for Plug-in Hybrid Electric Buses
We discuss a recently introduced ECO-driving concept known as SPONGE in the
context of Plug-in Hybrid Electric Buses (PHEB)'s.Examples are given to
illustrate the benefits of this approach to ECO-driving. Finally, distributed
algorithms to realise SPONGE are discussed, paying attention to the privacy
implications of the underlying optimisation problems.Comment: This paper is recently submitted to the IEEE Transactions on
Automation Science and Engineerin
Distributed charging management of multiâclass electric vehicles with different charging priorities
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166242/1/gtd2bf02710.pd
Topics in Electromobility and Related Applications
In this thesis, we mainly discuss four topics on Electric Vehicles (EVs) in the context of
smart grid and smart transportation systems.
The first topic focuses on investigating the impacts of different EV charging strategies on
the grid. In Chapter 3, we present a mathematical framework for formulating different EV
charging problems and investigate a range of typical EV charging strategies with respect to
different actors in the power system. Using this framework, we compare the performances of
all charging strategies on a common power system simulation testbed, highlighting in each
case positive and negative characteristics.
The second topic is concerned with the applications of EVs with Vehicle-to-Grid (V2G)
capabilities. In Chapter 4, we apply certain ideas from cooperative control techniques to
two V2G applications in different scenarios. In the first scenario, we harness the power
of V2G technologies to reduce current imbalance in a three-phase power network. In the
second scenario, we design a fair V2G programme to optimally determine the power dispatch
from EVs in a microgrid scenario. The effectiveness of the proposed algorithms are verified
through a variety of simulation studies.
The third topic discusses an optimal distributed energy management strategy for power
generation in a microgrid scenario. In Chapter 5, we adapt the synchronised version of the
Additive-Increase-Multiplicative-Decrease (AIMD) algorithms to minimise a cost utility
function related to the power generation costs of distributed resources. We investigate the
AIMD based strategy through simulation studies and we illustrate that the performance of
the proposed method is very close to the full communication centralised case. Finally, we
show that this idea can be easily extended to another application including thermal balancing
requirements.
The last topic focuses on a new design of the Speed Advisory System (SAS) for optimising
both conventional and electric vehicles networks. In Chapter 6, we demonstrate that, by
using simple ideas, one can design an effective SAS for electric vehicles to minimise group
energy consumption in a distributed and privacy-aware manner; Matlab simulation are give
to illustrate the effectiveness of this approach. Further, we extend this idea to conventional
vehicles in Chapter 7 and we show that by using some of the ideas introduced in Chapter
6, group emissions of conventional vehicles can also be minimised under the same SAS
framework. SUMO simulation and Hardware-In-the-Loop (HIL) tests involving real vehicles
are given to illustrate user acceptability and ease of deployment.
Finally, note that many applications in this thesis are based on the theories of a class
of nonlinear iterative feedback systems. For completeness, we present a rigorous proof on
global convergence of consensus of such systems in Chapter 2
Power quality and electromagnetic compatibility: special report, session 2
The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems.
Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages).
The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks:
Block 1: Electric and Magnetic Fields, EMC, Earthing systems
Block 2: Harmonics
Block 3: Voltage Variation
Block 4: Power Quality Monitoring
Two Round Tables will be organised:
- Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13)
- Reliability Benchmarking - why we should do it? What should be done in future? (RT 15
Recommended from our members
Open-Source, Open-Architecture SoftwarePlatform for Plug-InElectric Vehicle SmartCharging in California
This interdisciplinary eXtensible Building Operating SystemâVehicles project focuses on controlling plug-in electric vehicle charging at residential and small commercial settings using a novel and flexible open-source, open-architecture charge communication and control platform. The platform provides smart charging functionalities and benefits to the utility, homes, and businesses.This project investigates four important areas of vehicle-grid integration research, integrating technical as well as social and behavioral dimensions: smart charging user needs assessment, advanced load control platform development and testing, smart charging impacts, benefits to the power grid, and smart charging ratepayer benefits
Optimal Configuration of Extreme Fast Charging Stations Integrated with Energy Storage System and Photovoltaic Panels in Distribution Networks
Extreme fast charging (XFC) for electric vehicles (EVs) has emerged recently because of the short charging period. However, the extreme high charging power of EVs at XFC stations may severely impact distribution networks. This paper addresses the estimation of the charging power demand of XFC stations and the design of multiple XFC stations with renewable energy resources in current distribution networks. First, a Monte Carlo (MC) simulation tool was created utilizing the EV arrival time and state-of-charge (SOC) distributions obtained from the dataset of vehicle travel surveys. Various impact factors are considered to obtain a realistic estimation of the charging power demand of XFC stations. Then, a method for determining the optimal energy capacity of the energy storage system (ESS), ESS rated power, and size of photovoltaic (PV) panels for multiple XFC stations in a distribution network is presented, with the goal of achieving an optimal configuration. The optimal power flow technique is applied to this optimization so that the optimal solutions meet not only the charging demand but also the operational constraints related to XFC, ESS, PV panels, and distribution networks. Simulation results of a use case indicate that the presented MC simulation can estimate approximate real-world XFC charging demand, and the optimized ESS and PV units in multiple XFC stations in the distribution network can reduce the annual total cost of XFC stations and improve the performance of the distribution network
HVAC-based hierarchical energy management system for microgrids
With the high penetration of renewable energy into the grid, power fluctuations and supply-demand power mismatch are becoming more prominent, which pose a great challenge for the power system to eliminate negative effects through demand side management (DSM). The flexible load, such as heating, ventilation, air conditioning (HVAC) system, has a great potential to provide demand response services in the electricity grids. In this thesis, a comprehensive framework based on a forecasting-management optimization approach is proposed to coordinate multiple HVAC systems to deal with uncertainties from renewable energy resources and maximize the energy efficiency. In the forecasting stage, a hybrid model based on Multiple Aggregation Prediction Algorithm with exogenous variables (MAPAx)-Principal Components Analysis (PCA) is proposed to predict changes of local solar radiance, vy using the local observation dataset and real-time meteorological indexes acquired from the weather forecast spot. The forecast result is then compared with the statistical benchmark models and assessed by performance evaluation indexes. In the management stage, a novel distributed algorithm is developed to coordinate power consumption of HVAC systems by varying the compressorsâ frequency to maintain the supply-demand balance. It demonstrates that the cost and capacity of energy storage systems can be curtailed, since HVACs can absorb excessive power generation. More importantly, the method addresses a consensus problem under a switching communication topology by using Lyapunov argument, which relaxes the communication requirement. In the optimization stage, a price-comfort optimization model regarding HVACâs end users is formulated and a proportional-integral-derivative (PID)-based distributed algorithm is thus developed to minimize the customerâs total cost, whilst alleviating the global power imbalance. The end users are motivated to participate in energy trade through DSM scheme. Furthermore, the coordination scheme can be extended to accommodate battery energy storage systems (BESSs) and a hybrid BESS-HVAC system with increasing storage capacity is proved as a promising solution to enhance its selfregulation ability in a microgrid. Extensive case studies have been undertaken with the respective control strategies to investigate effectiveness of the algorithms under various scenarios. The techniques developed in this thesis has helped the partnership company of this project to develop their smart immersion heaters for the customers with minimum energy cost and maximum photovoltaic efficiency
Frequency Regulation with Heterogeneous Energy Resources: A Realization using Distributed Control
This paper presents one of the first real-life demonstrations of coordinated
and distributed resource control for secondary frequency response in a power
distribution grid. We conduct a series of tests with up to 69 heterogeneous
active devices consisting of air handling units, unidirectional and
bidirectional electric vehicle charging stations, a battery energy storage
system, and 107 passive devices consisting of building loads and photovoltaic
generators. Actuation commands for the test devices are obtained by solving an
economic dispatch problem at every regulation instant using distributed
ratio-consensus, primal-dual, and Newton-like algorithms. The distributed
control setup consists of a set of Raspberry Pi end-points exchanging messages
via an ethernet switch. The problem formulation minimizes the sum of device
costs while tracking the setpoints provided by the system operator. We
demonstrate accurate and fast real-time distributed computation of the
optimization solution and effective tracking of the regulation signal by
measuring physical device outputs over 40-minute time horizons. We also perform
an economic benefit analysis which confirms eligibility to participate in an
ancillary services market and demonstrates up to $53K of potential annual
revenue for the selected population of devices
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