Component condition and substation (S/S) reliability have a material impact on the cost of customer interruptions in electricity distribution systems (DSs). However, these factors are not usually considered within distribution system reconfiguration (DSR) problem formulations, because of the lack of a readily available methodology. This paper presents such a method, making use of component condition scores which are now mandatory for distribution system operators (DSOs) in the UK. Based on these condition scores, condition-based failure rate can be calculated for each component. S/S reliability is a function of component condition, S/S configuration and the network upstream of the S/Ss. The reliability of the S/S then has an impact on the reliability indices of each load point (LP) it supplies. These factors are combined to deliver a better informed algorithm for DSR, which is verified through its application on two DSs. The annual savings, compared to the formulation that neglects component condition and S/S reliability, can be in the order of tens of thousands of U.S. dollars for a single DS.

Virtual power plant (VPP) is a hybrid power system with a mesh of distributed resources, local loads and storage with both discrete and continuous variables involved. Control of such system requires advanced control schemes to make distributed assets act together to mimic an actual power plant. Previously, to study the behaviour of such systems, complex algorithms and modelling tools have been used but this paper proposes the use of Hybrid Automata (HA) as a convenient tool to model these systems. To demonstrate this, HA is used to model a VPP for a research farm owned by Newcastle University as a first step to design the control for the system.

Generally, decisions regarding power system operations are based only on operational parameters of the distribution network (DN) such as voltages, currents and power flows. Asset condition is a key parameter that is usually not considered by network management systems in their optimisation process. Against this background, this study seeks to indicate that the condition of power system assets can influence the network operation decisions. The criteria used to decide the optimal network operation are asset condition-based risk and losses. This is illustrated by a case study, where a number of network reconfigurations are examined in a representative DN and the results show that by taking asset condition information into account, then an improved operation of the network can be achieved.

Rural electricity customers are often subject to weak single-phase network connections. In this circumstance, powering three-phase equipment is not straightforward. This study addresses this problem through the development of a single- to three-phase power conversion system which is supplemented by the addition of energy storage on the DC bus of the converter. The storage is provided by a pair of second life electric vehicle (EV) batteries and charging is controlled by adjusting the DC bus voltage. The approach to, and challenges encountered in, developing this system are presented.

A methodology has been developed to compare different grid reinforcement solutions, ranging from conventional through hybrid to purely smart grid approaches. It evaluates alternative reinforcement solutions, subject to the constraints of the particular local network and situation. This methodology can be applied at all voltage levels and to both generic and actual networks. In the present study, it is applied to a representative medium voltage network of 4 feeders based on the IEEE 33-bus network. It focuses in particular on the implications of different reinforcement options on the expected annual level of network losses. The study concludes that the most effective reinforcement option depends on the anticipated load profile and growth in the location under consideration. It can be seen that energy losses have a significant impact on the choice of the most effective solution. It can also be seen that, under certain circumstances, a hybrid solution performs more effectively than either traditional reinforcement or pure smart grid solutions.

The potential for Distribution Network Operators (DNOs) to facilitate future network growth at the lowest costs for customers will come not only from smarter, more flexible network assets, but also from utilising customer flexibility, in the form of demand side response (DSR). To date, dynamic forms of DSR have been used commercially, mainly with Industrial and Commercial (I&C) customers, by the transmission system operator (TSO), and trials have been undertaken by DNOs with I&C, SME and residential customers on projects such as the Customer Led Network Revolution [1] This paper provides initial results from another Northern Powergrid (a UK DNO) project, entitled Activating Community Engagement (ACE) This project is being carried out in partnership with GenGame Ltd, Serious Games International Ltd and Newcastle University. Its aims are to examine both a new recruitment method for engaging domestic customers, and to test the GenGame's effectiveness in delivering residential DSR services to the distribution network not through tariff based incentives, but through the medium of gaming. The project commenced in 2015 and is jointly funded by Northern Powergrid from its network innovation allowance and by Innovate UK. Recruitment commenced in November 2015 and the project runs to the end of 2017. This paper presents preliminary results from a small number of initial trial members detailing the engagement structure and end-user data.

We explore how imprecise continuous time Markov chains can improve traditional reliability models based on precise continuous time Markov chains. Specifically, we analyse the reliability of power networks under very weak statistical assumptions, explicitly accounting for non-stationary failure and repair rates and the limited accuracy by which common cause failure rates can be estimated. Bounds on typical quantities of interest are derived, namely the expected time spent in system failure state, as well as the expected number of transitions to that state. A worked numerical example demonstrates the theoretical techniques described. Interestingly, the number of iterations required for convergence is observed to be much lower than current theoretical bounds.

The reliability of power supply to distribution network customers can be increased by embedded generation, including wind farms. The value of this increase in reliability needs to be evaluated, and national standards such as the Great Britain security of supply standard P2/6 seek to do so. This paper appraises the capacity credit evaluation methodology in P2/6 and outlines an alternative methodology to integrate generation with load more effectively, taking into account the topology, loading and reliability of the surrounding network. It concludes that under certain circumstances, the presence of embedded wind generation can allow the deferral of costly network reinforcement projects but that the time for which reinforcement can reasonably be deferred is a function not only of the generators themselves but also of the surrounding network. Copyright © 2014 John Wiley & Sons, Ltd.

Climate change as forecast by UKCP09 will affect the planning and operation of power transmission and distribution systems in Great Britain. The links between climate change and networks are identified. The risk of flooding is very likely to increase, with the greatest effect if substations are inundated. The optimal size and location of electricity transmission corridors is difficult to define because of uncertainty in the seasonal, regional and absolute changes to wind-speed and corresponding wind generation. Although equipment in Great Britain is already fundamentally designed to operate in the future conditions anticipated under climate change, marginal changes to the capabilities of equipment will need to be accounted for in parameters used in network planning procedures. The indirect effect of climate change, created by the political response designed to minimise greenhouse gas emissions, will be more significant than the direct impact of a changing climate. This will dramatically change the generation mix, overall demand and both seasonal and diurnal demand profiles. An industry with a wider range of tools and technical solutions for planning and operation will be more prepared to manage capacity, stability and reliability at lower cost than if present methods do not evolve.

The farming sector as a whole is a major customer group for electricity networks, as well as a major emitter of greenhouse gases. Moving the farmi ng sector towards a low carbon future is a high priori ty. New technologies including anaerobic digestion (AD) , wind and PV generation can facilitate this transiti on. These technologies have implications for the design and operation of the on-farm electrical network and its connection to the grid. For the farmer, a key issue can be the limitation caused by single phase supply. Fo r the distribution network operator, problems can be caus ed by the connection of new kinds of loads and generat ion onto weak rural networks with consequent pressure o thermal ratings, voltage constraints and fault curr ent limits. Possible solutions to these electrical problems include installing a back-to-back converter, electr ical energy storage, and demand side response. A case st udy is presented based on an actual farm in NE England where these solutions, together with on-farm electr ical and heating microgrids and an associated control system, are being implemented.

The Observatoire de Paris is involved in the Cherenkov Telescope Array (CTA) project by designing and constructing on the site of Meudon a Small Size Telescope prototype, named SST-GATE, in collaboration with the CHEC team (Compact High Energy Camera) which is providing the camera. The telescope structure is based on the Schwarzschild- Couder optical design which has never been adopted before in the design of a ground-based telescope. This concept allows a larger field of view and cheaper and smaller telescope and camera design with improved performance compared to the Davies-Cotton design traditionally used in very high energy gamma-ray telescopes. The SST-GATE telescope has been designed with the prime objectives of being light, versatile and simple to assemble with a minimal maintenance cost. This papers aims at reviewing the SST-GATE telescope structure from mechanics to optics along with the control command architecture; several innovative developments implemented within the design are discussed. Updates of the project status and perspectives are made.

In this paper, we discuss the performance matrix of the SST-GATE telescope developed to allow us to partition and allocate the important characteristics to the various subsystems as well as to describe the process in order to verify that the current design will deliver the required performance. Due to the integrated nature of the telescope, a large number of parameters have to be controlled and effective calculation tools must be developed such as an automatic performance budget. Its main advantages consist in alleviating the work of the system engineer when changes occur in the design, in avoiding errors during any re-allocation process and recalculate automatically the scientific performance of the instrument. We explain in this paper the method to convert the ensquared energy (EE) and the signal-to-noise ratio (SNR) required by the science cases into the “as designed” instrument. To ensure successful design, integration and verification of the next generation instruments, it is of the utmost importance to have methods to control and manage the instrument’s critical performance characteristics at its very early design steps to limit technical and cost risks in the project development. Such a performance budget is a tool towards this goal.

The Cherenkov Telescope Array (CTA) project aims to create the next generation Very High Energy (VHE) gamma-ray telescope array. It will be devoted to the observation of gamma rays over a wide band of energy, from a few tens of GeV to more than 100 TeV. Two sites are foreseen to view the whole sky where about 100 telescopes, composed of three different classes, related to the specific energy region to be investigated, will be installed. Among these, the Small Size class of Telescopes, SSTs, are devoted to the highest energy region, to beyond 100 TeV. Due to the large number of SSTs, their unit cost is an important parameter.At the Observatoire de Paris, we have designed a prototype of a Small Size Telescope named SST-GATE, based on the dual-mirror Schwarzschild-Couder optical formula, which has never before been implemented in the design of a telescope. Over the last two years, we developed a mechanical design for SST-GATE from the optical and preliminary mechanical designs made by the University of Durham. The integration of this telescope is currently in progress.Since the early stages of mechanical design of SST-GATE, finite element method has been used employing shape and topology optimization techniques to help design several elements of the telescope. This allowed optimization of the mechanical stiffness/mass ratio, leading to a lightweight and less expensive mechanical structure. These techniques and the resulting mechanical design are detailed in this paper. We will also describe the finite element analyses carried out to calculate the mechanical deformations and the stresses in the structure under observing and survival conditions.

The Cherenkov Telescope Array (CTA) project aims to create a next generation Very High Energy (VHE)γ-ray telescope array, devoted to the observation in a wide band of energy, from a few tens of GeV to more than 100 TeV. Two sites are foreseen to view the whole sky, with the main one in the Southern Hemisphere where about 100 telescopes of three different classes, related to the specific energy region to be investigated, will be installed. Among these, the Small Size class of Telescopes, SSTs, are 4-meter telescopes and are devoted to the highest energy region, from 1 TeV to beyond 100 TeV. Some of these sites considered for CTA exhibit strong seismic constraints. At the Observatoire de Paris, we have designed a prototype of a Small Size Telescope named SST-GATE, based on the dual-mirror Schwarzschild-Couder optical formula, which was never before implemented in the design of a Cherenkov telescope. The integration of this telescope on the site of the Observatoire de Paris is currently in progress. Technical solutions exist in the literature to protect structures from dynamic loads caused by earthquakes without increasing the mass and cost of the structure. This paper presents a state of the art of these techniques by keeping in mind that the operational performance of the telescope should not be compromised. The preliminary seismic analysis of SSTGATE performed by the finite element method is described before.

Installed capacities of distributed generation (DG) are projected to increase substantially in Great Britain and many other power systems. This paper will discuss the definition of capacity value of DG arising from its ability to support additional demand without the need for new network capacity, in analogy with the definition of effective load carrying capability (ELCC) at transmission level. This calculated ELCC depends on the precise detail of its definition; in particular in a demand group fed by a pair of circuits where the double outage state dominates the calculated reliability index, the ELCC will be very small unless the generator can run in islanded mode. Finally, requirements for use in practical planning studies and development of formal planning standards will be discussed.

We present the results of a project to develop a proof of concept for a novel hyperspectral imager based on the use of advanced micro-optics technology. The technology gives considerably more spatial elements than a classic pushbroom which translates into far more light being integrated per unit of time. This permits us to observe at higher spatial and/or spectral resolution, darker targets and under lower illumination, as in the early morning. Observations of faint glow at night should also be possible but need further studies. A full instrument for laboratory demonstration and field tests has now been built and tested. It has about 10,000 spatial elements and spectra 150 pixel long. It is made of a set of cylindrical fore-optics followed by a new innovative optical system called a microslice Integral Field Unit (IFU) which is itself followed by a standard spectrograph. The fore-optics plus microslice IFU split the field into a large number of small slit-like images that are dispersed in the spectrograph. Our goal is to build instruments with at least hundreds of thousands of spatial elements.