Managing renewable intermittency in smart grid:use of residential hot water heaters as a form of energy storage

This paper discusses a novel wind generation balancing technique to improve renewable energy integration to the system. Novel individual hot water heater controllers were modelled with the ability to forecast and look ahead the required energy, while responding to electricity grid imbalance. Artificial intelligence and machine learning techniques were used to learn and predict energy usage. In this research wind power data was used in most cases to represent the supply side, where focus was on the actual generation deviation from plan. It proved to be possible to balance the generation and increase system efficiency while maintaining user satisfaction. The methods developed in this research are not limited to wind power balancing and can also be used with any other type of renewable generation source

Design and development of a real-time readout electronics system to retrieve data from a square multi-anode photomultiplier tube for neutron gamma pulse shape discrimination

Pulse Shape Discrimination (PSD) algorithms can reliably separate neutrons and gamma-ray photons interacting in a scintillation detector. When implemented in the digital domain, the PSD algorithms allow real-time discrimination between neutron and gamma sources. This paper presents a design of a readout electronics system to retrieve data from a multi-anode photomultiplier tube (MAPMT) for a scintillator based coded-aperture neutron imager. The scintillator is to be coupled with Hamamatsu H9500, a square MAPMT, where each anode of the MAPMT is linked to a resistor network to infer the position of incidence of radiation within the scintillant. Additionally, the resistor network output signals are to be filtered through a novel noise reduction circuit to preserve the data corresponding to each pulse. Localised pulses are digitised using high sampling rate Analogue to Digital Converter (ADC). Sampled signals are temporarily stored in a local ping-pong buffer, before being processed on a field programmable gate array (FPGA). Initial results suggest that 150 MSPS rate provides sufficient information for neutron gamma source discrimination using PSD. Parallel real-time signal processing, implemented on the FPGA, enables multi-channel functioning to generate an array of interactions within the scintillator in terms of gamma rays and neutrons

Distributed energy storage using residential hot water heaters

This paper proposes and analyses a new demand response technique for renewable energy regulation using smart hot water heaters that forecast water consumption at an individual dwelling level. Distributed thermal energy storage has many advantages, including high overall efficiency, use of existing infrastructure and a distributed nature. In addition, the use of a smart thermostatic controller enables the prediction of required water amounts and keeps temperatures at a level that minimises user discomfort while reacting to variations in the electricity network. Three cases are compared in this paper, normal operation, operation with demand response and operation following the proposed demand response mechanism that uses consumption forecasts. The results show that this technique can produce both up and down regulation, as well as increase water heater efficiency. When controlling water heaters without consumption forecast, the users experience discomfort in the form of hot water shortage, but after the full technique is applied, the shortage level drops to nearly the starting point. The amount of regulation power from a single dwelling is also discussed in this paper

Multiple metrics-OLSR in NAN for Advanced Metering Infrastructures

Routing in Neighbourhood Area Network (NAN) for Smart Grid's Advanced Metering Infrastructure (AMI) raises the need for Quality of Service (QoS)-Aware routing. This is due to the expanded list of applications that will result in the transmission of different types of traffic between NAN devices (i.e smart meters). In wireless mesh network (WMN) routing, a combination of multiple link metrics, though complex, has been identified as a possible solution for QoS routing. These complexities (i.e Np complete problem) can be resolved through the use of Analytical Hierarchy Process (AHP) algorithm and pruning techniques. With the assumption that smart meters transmit IP packets of different sizes at different interval to represent AMI traffic, a case study of the performance of three Optimised Link State Routing (OLSR) link metrics is carried out on a grid topology NAN based WMN in ns-2 network simulator. The best two performing metric were used to show the possibility of combining multiple metrics with OLSR through the AHP algorithm to fulfill the QoS routing requirements of targeted AMI application traffic in NANs

Coded-aperture imaging systems:past, present and future development - a review

Scintillator based coded-aperture imaging has proven to be effective when applied for X- and gamma-ray detection. Adaptation of the same method for neutron imaging has resulted in a number of propitious systems, which could be potentially employed for neutron detection in security and nuclear decommissioning applications. Recently developed scintillator based coded-aperture imagers reveal that localisation of neutron sources using this technique may be feasible, since pulse shape discrimination algorithms implemented in the digital domain can reliably separate gamma-rays from fast neutron interactions occurring within an organic scintillator. Moreover, recent advancements in the development of solid organic scintillators make them a viable solution for nuclear decommissioning applications as they present less hazardous characteristics than currently dominating liquid scintillation detectors. In this paper existing applications of coded-apertures for radiation detection are critically reviewed, highlighting potential improvements for coded-aperture based neutron source localisation. Further, the suitability of coded-apertures for neutron imaging in nuclear decommissioning is also assessed using Monte-Carlo modelling

Performance analysis of variable Smart Grid traffic over ad hoc Wireless Mesh Networks

Recent advances in ad hoc Wireless Mesh Networks (WMN) has posited it as a strong candidate in Smart Grid's Neighbourhood Area Network (NAN) for Advanced Metering Infrastructure (AMI). However, its abysmal capacity and poor multi-hoping performance in harsh dynamic environment will require an improvement to its protocol stacks in order for it to effectively support the variable requirements of application traffic in Smart Grid. This paper presents a classification of Smart Grid traffics and examines the performance of HWMP (which is the default routing protocol of the IEEE 802.11s standard) with the Optimised Link State Routing (OLSR) protocol in a NAN based ad hoc WMN. Results from simulations in ns-3 show that HWMP does not outperform OLSR. This indicates that cross layer modifications can be developed in OLSR protocol to address the routing challenges in a NAN based ad hoc WMN

Pulse shape discrimination characteristics of stilbene crystal, pure and 6Li loaded plastic scintillators for a high resolution coded-aperture neutron imager

Pulse shape discrimination performances of single stilbene crystal, pure plastic and 6Li loaded plastic scintillators have been compared. Three pulse shape discrimination algorithms have been tested for each scintillator sample, assessing their quality of neutron/gamma separation. Additionally, the digital implementation feasibility of each algorithm in a real-time embedded system was evaluated. Considering the pixelated architecture of the coded-aperture imaging system, a reliable method of simultaneous multi-channel neutron/gamma discrimination was sought, accounting for the short data analysis window available for each individual channel. In this study, each scintillator sample was irradiated with a 252Cf neutron source and a bespoke digitiser system was used to collect the data allowing detailed offline examination of the sampled pulses. The figure-of-merit was utilised to compare the discrimination quality of the collected events with respect to various discrimination algorithms. Single stilbene crystal presents superior neutron/gamma separation performance when compared to the plastic scintillator samples

Radiation Imaging with Fast Organic Liquid Scintillator Detectors

Development of technologies for the rapid, in-situ characterisation of contaminated facilities (where man-entry is not possible) is a key requirement to speed up nuclear decommissioning. Similarly prevention of nuclear terrorism is dependent upon the accuracy and strength of the radiation monitoring systems. Organic liquid scintillator detectors are becoming popular in radiation detection applications including nuclear decommissioning, nuclear safety and security as a result of recent advances in digital pulse-shape discrimination methods. They generally sensitive to both neutrons and gamma rays, where pulse shape discrimination can be used to discriminate between neutrons and gamma rays. In this work, experimentally collected events are discriminated between neutrons and gamma-rays using pulse shape discrimination, and images produce for each measurement in terms of the angular distribution (i.e. intensity of the radiation type) of events for total counts, gamma rays and neutrons. Based on these images, it can be easily identified the actual location of the source