Scenarios for the Development of Smart Grids in the UK: Literature Review

This Working Paper reviews the existing literature on the socio-technical aspects of smart grid development. This work was undertaken as part of the Scenarios for the Development of Smart Grids in the UK project

Can the equitable roll out of electric vehicle charging infrastructure be achieved?

Equitable and sufficient charging infrastructure is required for transport decarbonization to reach its goals. Despite increased electric vehicle infrastructure roll out rates, there is still considerable uncertainty regarding the charging market. For example, studies have evidenced disparities in electric vehicle charging placement, however, predictable as the market caters for early adopters. While there is an emerging discourse surrounding social equity in charging infrastructure, this is scattered across interdisciplinary research covering broader aspects of electric vehicle infrastructure provision with a lack of studies consolidating issues. This study aims to synthesize evidence on social equity in various aspects of electric vehicle charging infrastructure provision and set an agenda for centering social equity in the debate. Findings of this critical synthesis of research have helped to draw out the complexities involved in the equitable roll out of electric vehicle charging infrastructure, which are interlinked with an array of other dimensions including the affordability of electric vehicle purchase. Research into solutions and best practice has shown examples of local target setting, monetary incentives (grants, loans and rebates for electric vehicle purchase and charging infrastructure and smart energy tariffs) and other policy incentives (increased public overnight charging, electric car-clubs, extended battery warranties for second-hand vehicles) that can or have been employed to redress the balance. The outcomes could be utilized when developing and implementing electric vehicle strategies to support uptake across all people. Policy implications and further study suggested could ensure that communities and individuals are not locked out of the benefits of investment

A model reference-based adaptive PSS4B stabilizer for the multi-machines power system

Two-inputs adaptive IEEE multi-bands power system stabilizer (PSS4B) was developed for oscillations damping control in power systems. Two supplementary loops based on model reference (MR) adaptive control were added to the typical PSS4B design. The MR has the same loops’ parameters of the typical PSS4B, and hence, avoiding a complex tuning process. The proposed PSS has a self-tuning gain reduction block to avoid any negative impact due to the high gains value during the disturbance time. The proposed PSS was applied on the four-machine benchmark power system. To evaluate the robustness of the proposed PSS, it was tested in comparison with the Delta W PSS, one-input multi-bands PSS4B (1iMB) and two-inputs multi-bands PSS4B (2iMB) stabilizers. The integration of the proposed PSS was demonstrating using different study cases. These cases consider the small-signal stability (SSS), large-signal stability (LSS) and the coordination test for the local and inter-area excited power modes. The proposed PSS demonstrated robust and superior responses in all cases

Scenarios for the Development of Smart Grids in the UK: Synthesis Report

Building on extensive expert feedback and input, this Research Report describes four smart grid scenarios which consider how the UK' electricity system might develop to 2050. The scenarios outline how political decisions, as well as those made in regulation, finance, technology, consumer and social behaviour, market design or response, might affect the decisions of other actors and limit or allow the availability of future options

Modelling Li+ Ion Battery Electrode Properties

We formulated two detailed models for an electrolytic cell with particulate electrodes based on a lithium atom concentration dependent Butler-Volmer condition at the interface between electrode particles and the electrolyte. The first was based on a dilute-ion assumption for the electrolyte, while the second assumed that Li ions are present in excess. For the first, we used the method of multiple scales to homogenize this model over the microstructure, formed by the small lithium particles in the electrodes. For the second, we gave rigorous bounds for the effective electrochemical conductivity for a linearized case. We expect similar results and bounds for the "full nonlinear problem" because variational results are generally not adversely affected by a sinh term. Finally we used the asymptotic methods, based on parameters estimated from the literature, to attain a greatly simplified one-dimensional version of the original homogenized model. This simplified model accounts for the fact that diffusion of lithium atoms within individual electrode particles is relatively much faster than that of lithium ions across the whole cell so that lithium ion diffusion is what limits the performance of the battery. However, since most of the potential drop occurs across the Debye layers surrounding each electrode particle, lithium ion diffusion only significantly affects cell performance if there is more or less complete depletion of lithium ions in some region of the electrolyte which causes a break in the current flowing across the cell. This causes catastrophic failure. Providing such failure does not occur the potential drop across the cell is determined by the concentration of lithium atoms in the electrode particles. Within each electrode lithium atom concentration is, to leading order, a function of time only and not of position within the electrode. The depletion of electrode lithium atom concentration is directly proportional to the current being drawn off the cell. This leads one to expect that the potential of the cell gradually drops as current is drawn of it. We would like to emphasize that all the homogenization methods employed in this work give a systematic approach for investigating the effect that changes in the microstructure have on the behaviour of the battery. However, due to lack of time, we have not used this method to investigate particular particle geometries

A coordinated optimal programming scheme for an electric vehicle fleet in the residential sector

The development of intelligent strategies to manage electric vehicle charging process is the key for fostering a proper diffusion of electric vehicles at customer premises. The presence of renewable generation and the exploitation of vehicle-to-grid can enhance this process. In this paper, two procedures are proposed for optimizing electric vehicle charging strategies, for an aggregation of consumers, with the objectives of load profile levelling and total cost minimization, in the presence of possible realistic diffusion of photovoltaic systems and electric vehicles. Moreover, the best compromise between the two objectives is evaluated by determining techno-economic merit indicators. The procedures are applied to a realistic case study in the UK, considering an aggregator managing a group of residential customers in a low-voltage distribution network, where multiple tariff schemes are assessed

Scenarios for the Development of Smart Grids in the UK: Literature Review

This Working Paper reviews the existing literature on the socio-technical aspects of smart grid development. This work was undertaken as part of the Scenarios for the Development of Smart Grids in the UK project

Optimal placement and capacity of distributed generators in medium voltage generic UK network

Due to global environmental concerns, new opportunities are opening up for harnessing of resources from renewable energy. Currently, distributed generators (DG) which are based on renewable energy technologies such as solar, wind, and biomass are widely used in power systems. The presence of DG has potential to improve reliability of the network and minimise power losses. This work analyse the impact of DG in distribution networks and determine the optimum size and location of DG to reduce losses. Location and sizing of DG are challenging tasks due to an extensive number of possibilities and constraints to be considered. Therefore, the proposed optimisation method is capable to identify the optimal DG size and location considering additional load from EV charging stations. The developed optimisation algorithm is simulated in MATLAB programming using an MV generic UK network. Various case studies were implemented including single and multiple DGs connection to the network in order to reduce the losses and to maintain the voltage within statutory limits