Showing papers by "Graham Town published in 2016"

Towards an internet of energy

Abstract: The current model of centralized electricity generation, transmission and distribution is under pressure to change for a variety of reasons; environmental concerns are driving a shift away from large coal-fired generation systems to increasing adoption of renewable energy sources, which tend to be distributed and not always available on demand, and hence requiring distributed storage support. Moreover, to support electric vehicles, energy needs to be provided as a service to consumers independent of location, rather than a product delivered and billed to a fixed location. In this work, we compare and contrast modern internet and energy networks and services, identifying key functionalities and the main technical challenges to be faced in transforming the electricity distribution system to a flexible yet reliable and robust platform for the exchange of electrical energy.

Improved peak shaving in grid-connected domestic power systems combining photovoltaic generation, battery storage, and V2G-capable electric vehicle

Abstract: Strategic use of domestic battery storage in households with a V2G-capable electric vehicle and photovoltaic generation is shown to be capable of shaving the peak loading on the electricity distribution grid under realistic operating conditions by up to 37%. The additional degree of freedom provided by combining the EV and domestic storage is shown to enable additional reductions in peak grid load. A smart control algorithm is described for coordinating the system components to reduce peak grid load and improve power quality.

Electric vehicle charge scheduling using an artificial neural network

Abstract: With the integration of EVs into the power grid, smart metering using machine-to-machine (M2M) communication is likely to play an important role in real-time energy management and control. Smart devices embedded with advanced metering infrastructure (AMI) can forecast the energy demand as well as perform energy pricing in real time. In this paper, an artificial neural network (ANN) based intelligent decision-making system is presented that utilises data logged by an M2M AMI for EV charge scheduling and load management. The ANN was trained using household power consumption and EV energy demand data, and was used to decide when a vehicle should charge (G2V), or could discharge (V2G).

An intelligent driver alerting system for real-time range indicator embedded in electric vehicles

Abstract: This paper proposes a state-of-the-art algorithm for a real time charging recommendation for an electric vehicle (EV) driver based on an accurate real-time range indicator system to avoid range anxiety. The charging recommendation algorithm alerts the driver when charging is deemed required for the selected route. This algorithm determines the nearest charging location obtained using GPS based on an accurate estimation of SoC at the destination and when charging determines the optimum charging time required by the battery to have sufficient energy to reach the destination. The graphical user interface (GUI) of the real-time range indicator system is also used to show the driver an accurate estimation of the remaining range to destination and the current state of charge (SoC). The results from simulations of a range of routes validate the proposed algorithm.

Simple and Accurate Fluorescence Lifetime Measurement Scheme Using Traditional Time-Domain Spectroscopy and Modern Digital Signal Processing

Abstract: Fluorescence lifetime measurement is an essential process for evaluation and application of optical gain media. An accurate and convenient scheme for fluorescence lifetime measurement of complex emission processes with either single or multiple fluorescence lifetimes is essential. We developed a new convolution-based scheme for fluorescence lifetime measurement. The innovation of the scheme lies in a combination of convolution-based digital signal processing algorithms with a low cost and simple time-domain spectroscopic setup. The convolution-based scheme is able to achieve accurate microsecond fluorescence lifetime resolution using the spectroscopic setup with only millisecond fluorescence lifetime resolution, for both single or multiple fluorescence lifetimes. We demonstrated the performance of the scheme, both theoretically and experimentally, by measuring fluorescence lifetimes associated with complicated emission processes in bismuth–erbium-doped fibers and erbium-doped fiber.

Cure monitoring of two-component epoxy adhesives by terahertz time-domain spectroscopy

Abstract: We report nondestructive measurements of the properties of two-component epoxy adhesives at terahertz wavelengths using a transmissive time-domain spectroscopy system. The results show that the different epoxies have measurably different THz properties, that the changes which occur during the curing process can be monitored by measurements of their refractive index and absorption at terahertz wavelengths, and that this technique is sensitive enough to record changes in the optical material parameters during the postcuring process.

A quasi-periodic modulation strategy to mitigate EMI for a GaN-based quasi-Z-source DC-DC converter

Abstract: Wide-bandgap (WBG) switching devices, such as gallium nitride (GaN), enable switching at high frequencies with low rise and fall times. This provides advantages such as high power density and compact size, however a potential unwanted side-effect is increased electromagnetic interference (EMI) because of large transient currents. A novel quasi-periodic modulation scheme is described for voltage-fed quasi-Z-source (qZS) DC-DC converters which substantially reduces the peak EMI. The driver logic required is simple and generic, and therefore adaptable to all modulation schemes proposed to date for isolated qZS DC-DC converters. Various experimental results verify the effectiveness of the proposed strategy in terms of voltage gain, efficiency and EMI suppression.

Program-based peer assisted learning

Abstract: PURPOSE The aim of this research was to identify and develop a PAL framework and activities with the following features: i) A focus on competencies developed throughout degree programs, rather than selected units, ii) involve and serve students across all years of their learning program, iii) enable and encourage students to take responsibility for developing, managing and sustaining PAL groups and activities. The research is being conducted in the context of an engineering degree program, but we are seeking to develop a framework that, with appropriate changes, will be relevant in any discipline.

Improved estimation of the impact of regenerative braking on electric vehicle range

Abstract: In this paper, a mathematical model for calculating regenerative braking (RB) energy considering the time-varying efficiency of a common electric vehicle (EV) is presented, taking into account environmental conditions. The contribution factor (CF) for estimating the impact of the RB system on the total consumed energy is calculated. To validate the calculated CF, a Blade Electron EV (Converted Hyundai Gets) was driven along a selected route in Australia and the measured CF is then compared with that of the calculated one. The results clearly demonstrate the accuracy of the mathematical model. The effect of the change in the elevation and speed limit profiles along the route on the total consumed energy using the RB system is also discussed. Finally, the estimated state of charge (SoC) of the battery is then compared with the measured SoC along the selected route.

Characterization of trapping in a GaN HEMT by performing isothermal three-stage pulse measurements

Abstract: Modern microwave circuit performance is susceptible to dispersion of the characteristics of microwave FETs. This is because the complex signals used in communication systems invoke charge trapping and self-heating mechanisms. These mechanisms are sensitive to bias, temperature, and frequency variations. A major difficulty in characterizing charge trapping in microwave FETs is to differentiate between the self-heating and charge trapping rates. In this paper, the trapping behavior in a GaN HEMT is characterized by performing isothermal three-stage pulse measurements.

Alvarez optical components in the THz regime

Abstract: We present a concept to design arbitrary Alvarez-like optical devices. As an example we demonstrate a variable spiral phase plate, which produces a vortex beam.