Chemical Energy Converters

Analytical Approach to Characterize the Effect of Engine Control Parameters and Fuel Properties on ACI Operation in a GDI Engine

Student(s): Johannes Rohwer
Cohort: Cohort 3
Date: 01 01 2020

Advanced compression ignition (ACI) operation in gasoline direct injection (GDI) engines is a promising concept to reduce fuel consumption and emissions at part load conditions. However, combustion phasing control and the limited operating range in ACI mode are a perennial challenge. In this study the combined impact of fuel properties and engine control strategies in ACI operation are investigated. A DOE was implemented to determine the sensitivity of engine control parameters on the engine load, combustion noise and stability under low load ACI operation for three RON 98 gasoline fuels, each exhibiting disparate chemical composition. Furthermore, the thermodynamic state of the compression histories was studied with the aid of the pressure-temperature framework. Due to the compression ratio constraints imposed by knock limited SI operation, considerable intake temperature heating was required and ACI operation resulted in the intermediate to high temperature autoignition regime. The olefin containing fuel was found to be most sensitive to intake air heating, thereby enhancing its potential suitability for ACI operation, while still enabling high load SI operation. This work was conducted during Johannes’s employment Argonne National Laboratory.

Digital Systems, Optimisation and Integration

Blade Surface Pressure Measurements on a Low Pressure Rise Axial Flow Fan

Proceedings of the ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine; Fans and Blowers
Student(s): Johannes Rohwer
Cohort: Cohort 3
Date: 25 09 2020

Fan performance characteristic tests of axial flow fans provide information on the global flow field, based on stable inlet flow field distribution. More information is often required on the local flow distribution existing in the vicinity of the fan blades. In this study, a numerical and experimental investigation of a large diameter axial flow fan is conducted to investigate its local pressure distribution and performance. Two specially constructed M-Fan blades with thirty-five pressure taps at five radial locations are manufactured to conduct blade surface pressure measurements on the blades. The experimental M-Fan results are compared against results from a periodic numerical CFD model of a fan blade modelled in an ISO 5801, Type A test facility configuration. The experimental tests and numerical model correlate well with each other and details of the fan blade performance are provided in the paper. This work was conducted during Johannes’s Master of Mechanical Engineering (MEng) at the University of Stellenbosch.

Digital Systems, Optimisation and Integration

A Case for Technology - Forcing Transformative Changes in the Formula 1 Power Unit

SAE International
Student(s): Abdu Elmagdoub
Cohort: Cohort 2
Date: 06 04 2021

A key chapter from Abdu's Master's thesis at Oxford Brookes University exploring Supervised Neural Network based Machine Learning Algorithms to Predict and Reduce Emissions in Internal Combustion Engines for Racing Applications was accepted for publication by SAE International 

The paper is titled "A Case for Technology - Forcing Transformative Changes in the Formula 1 Power Unit". Following a systematic methodology, it analytically examines area-specific emissions in F1 race events at different track stadia and proposes new targets for F1 power units in conjunction with current World Health Organization (WHO) and European Commission published exposure ug/m³ standards.

Propulsion Electrification

Is Elevated Operational Temperature a Barrier to Solid-State Battery Adoption?

Climate Exp0
Student(s): Ryan Hughes
Cohort: Cohort 2
Date: 17 05 2021

Ryan presented the work from his MSc dissertation on solid-state battery at the Climate Exp0 conference in the Mitigation Solutions theme. With his supervisor Dr Christopher Vagg, he found that by utilising waste heat from the electrical power train, there is enough energy to heat thermally isolated solid-state battery modules in time for them to provide tractive power for a passenger vehicle. This is important as currently available solid-state batteries require an operational temperature of 60°C.

Chemical Energy Converters

Turbocompounding the Opposed-Piston 2-Stroke Engine

SAE 2021 World Congress
Student(s): Alex Young
Cohort: Cohort 1
Date: 22 09 2021

For Alex's MRes summer project, he studied the effects of “Turbocompounding the Opposed-Piston 2-Stroke (OP2S) Engine” with a focus on quantifying the expected Brake Specific Fuel Consumption (BSFC) improvement. In order to achieve this, Alex needed to first create a model of an OP2S engine within GT Power, an engine simulation software package. After the MRes year was finished, Alex was able to turn the summer research project report into a conference paper which was published as part of the SAE WCX World Congress Experience Digital Summit in 2021.

Chemical Energy Converters

The Effect of Crankshaft Phasing and Port Timing Asymmetry on Opposed-Piston Engine Thermal Efficiency

Student(s): Alex Young
Cohort: Cohort 1
Date: 15 10 2021

Opposed-piston two-stroke engines reveal degrees of freedom that make them excellent candidates for next generation, highly efficient internal combustion engines for hybrid electric vehicles and power systems. The effect of crankshaft phasing and intake and exhaust port height-to-stroke ratios on a range of scavenging performance parameters and other effects are explored in depth in his latest article in Energies: “The Effect of Crankshaft Phasing and Port Timing Asymmetry on Opposed-Piston Engine Thermal Efficiency”, where it has been shown that lean operation favours port timing asymmetry, whereas, under stoichiometric conditions, best efficiencies are found during symmetrical port timing. 

Propulsion Electrification

Assessing the Feasibility of a Cold Start Procedure for Solid State Batteries in Automotive Applications

Student(s): Ryan Hughes
Cohort: Cohort 2
Date: 05 02 2022

Originating from his Master's thesis, Ryan and his supervisor Dr Chris Vagg have published their findings in a new journal article seeking to address the feasibility of a cold start procedure for solid state batteries in automotive applications. The proposed solution involves dividing the battery into sub-packs and heating them sequentially to the required 60°C, primarily using waste heat from the electric powertrain. This could allow high energy density solid state cells to be used despite their temperature constraints.

Propulsion Electrification

Effect of Internal AC Heating on the Temperature Homogeneity of Different Size Battery Cells

Student(s): Howard Richards
Cohort: Cohort 2
Date: 12 02 2022

Howard's MRes Summer Project investigated the effect that AC internal heating had on the spatial temperature homogeneity of Lithium-ion cells. With his supervisor Dr Christopher Vagg, he found that the cylindrical MoliCel and DTP Pouch cells both demonstrated significant temperature gradients when heated from sub-zero temperatures. These gradients increased in magnitude with the size of the cell and for the pouch cells were affected further by the current gradients caused by tabs located at the same end of the battery.

Chemical Energy Converters

Investigations into EGR dilution tolerance in a pre-chamber ignited GDI engine

Student(s): Johannes Rohwer
Cohort: Cohort 3
Date: 01 03 2022

EGR is a useful means to improve fuel economy in spark-ignited gasoline engines, while also reducing NOx emissions due to the lower peak cylinder temperatures. However, the ability of conventional spark ignition systems to reliably ignite dilute mixtures limits the dilution tolerance due to the onset of combustion instability.  In this study, an active pre-chamber system was simulated and experimentally tested with various EGR rates to provide insight into its operation and performance metrics. This included an assessment of the thermodynamic states and composition over different pre-chamber operating conditions. The active pre-chamber extended the EGR dilution limit from 20% for conventional SI to above 30%, with a higher pre-chamber flow rate (more scavenging) resulting in increased combustion stability. A trade-off between the jet momentum and spark timing was observed when analysing the simulations and the pre-chamber jet momentum was found to decrease with increasing EGR rate. This work was conducted during Johannes’s employment Argonne National Laboratory.

Chemical Energy Converters

Investigation of Naphtha-Type Biofuel from a Novel Refinery Proces

WCX SAE World Congress Experience
Student(s): Immanuel Vinke
Cohort: Cohort 1
Date: 29 03 2022

In order to reduce the carbon footprint of the Internal Combustion Engine (ICE), biofuels have been in use for a number of years. One of the problems with first-generation (1G) biofuels however is their competition with food production. In search of second-generation (2G) biofuels, that are not in competition with food agriculture, a novel biorefinery process has been developed to produce biofuel from woody biomass sources. This novel technique, part of the Belgian federal government funded Ad-Libio project, uses a catalytic process that operates at low temperature and is able to convert 2G feedstock into a stable light naphtha. The bulk of the yield consists out of hydrocarbons containing five to six carbon atoms, along with a fraction of oxygenates and aromatics. The oxygen content and the aromaticity of the hydrocarbons can be varied, both of which have a significant influence on the fuel’s combustion and emission characteristics when used in Internal Combustion Engines. When used as a blend component, this novel 2G biofuel could help increase the sustainability of vehicle fuels. But, while exhaustive experimental and, although lesser in number, numerical investigations on combustion behavior have been performed for 1G biofuels, less information is available for 2G biofuels and especially this novel naphtha-like fuel. An extensive fuel compound property database and a fuel blend property calculator is readily available in literature, but their validity has not been tested for the novel 2G biofuel components. This article provides a first screening of the usability of these light naphtha components as blend components for gasoline and diesel drop-in fuels, by means of a freely available fuel component database and fuel blend calculator, concluding with an initial assessment of achievable blends and pointing out where further work is needed.

Sustainability and Low Carbon Transition

Mobility As a Service: Why and How?

City Changers
Cohort: Cohort 2
Date: 04 04 2022

Originating from her PhD research on Mobility as a Service (MaaS), Rita wrote a short article for the City Changers website on balancing the benefits and challenges of implementing MaaS in an urban context, providing a few practical steps towards a MaaS implementation.

Digital Systems, Optimisation and Integration

Freevalve: Control and Optimization of Fully Variable Valvetrain-enabled Combustion Strategies for High Performance Hybrid Vehicles

SAE Technical Papers
Student(s): Abdu Elmagdoub
Cohort: Cohort 2
Date: 13 08 2022

With ever stricter legislative requirements for CO2 and other exhaust emissions, significant effort by Original Equipment Manufacturers (OEMs) have launched a number of different technological strategies to meet these challenges such as Battery Electric Vehicles (BEVs). However, a multiple technology approach is needed to deliver a broad portfolio of products since battery costs and supply constraints are considerable concerns hindering mass uptake of BEVs. Therefore, further investment in IC engine technologies to meet these targets are being considered, such as lean burn gasoline technologies and other high efficiency concepts such as dedicated hybrid engines. Hence, it becomes of sound reason to further embrace diversity and develop complementary technologies to assist in rapid conclusions in the transition to the next generation hybrid powertrains. One such approach is to provide increased valvetrain flexibility to afford new degrees of freedom in engine operating strategies. Freevalve is an electronically controlled, pneumatic spring-based, valve actuation system enabling independent control of ICE valves conceptualized by Koenigsegg’s Freevalve AB. Developed primarily in line with increasingly strict emissions legislations, preliminary findings have demonstrated that the cam-less engine technology withholds significant potential, offering up to 10% decreased fuel consumption and 60% less cold start emissions on an average drive cycle. This paper aims to demonstrate the most recent valve operating strategies enabled by the cam-less engine technology using a simplified 3-cylinder hybrid 1D engine model in GT-Suite.

Propulsion Electrification

Carbon Fibre Lattice Strain Mapping Via Microfocus Synchrotron X-Ray Diffraction of a Reinforced Composite

Journal: Carbon
Cohort: Cohort 1
Date: 11 08 2022

Thomas and Rob aided a Synchrotron X-Ray diffraction (SXRD) strain analysis experiment on Carbon Fibre Reinforced Polymers (CFRPs), at Diamond Lightsource. This was the first micro-scale quantification of micro-scale lattice strain in carbon fibre. This work determines the effect of load has on the axial and longitudinal strain of turbostratic atomic structure of the composite material.

Transport, Behaviour and Society

Climate anxiety: What predicts it and how is it related to climate action?

Journal of Environmental Psychology
Student(s): Lois Player
Cohort: Cohort 2
Date: 02 09 2022

Lois Player, AAPS CDT student, co-authors a study that finds that whilst climate anxiety is low amongst the UK public, it may be an important driver of climate action such as cutting down on waste.

The study published in the Journal of Environmental Psychology coincides with a new briefing paper from the Centre for Climate Change & Social Transformations focused on UK public preferences for low-carbon lifestyles. Its analysis suggests that lifestyle changes (for example, reducing car use or eating less meat), are increasingly seen as both feasible and desirable.

In the paper, the authors emphasise the importance of the media as a motivating force for the lifestyle changes required as we decarbonise. They suggest that the media and public discourse about climate anxiety has the power to create a positive vision for a greener, cleaner future which is significantly less dependent on fossil fuels.

Lois explained: “Our results suggest that the media could play an important role in creating positive pro-environmental behaviour change, but only if they carefully communicate the reality of climate change without inducing a sense of hopelessness.”

Sustainability and Low Carbon Transition

The Path to Sustainable and Equitable Mobility: Defining a Stakeholder-Informed Transportation System

Cohort: Cohort 2
Date: 30 11 2022

A transportation system should be designed considering the relevant stakeholders’ needs for a fundamental transformation in travelling behaviour. This research aims to contribute to that by characterising the future network in response to the stakeholders’ requirements, using a systematic literature review paired with a grounded theory approach. Out of 39 reviewed publications, 13 transportation indicators were clustered into six dimensions representing stakeholders’ requirements for the transportation system. These results depict a stakeholder-informed land transportation system as a system of accessible and integrated mode services, which should be supported by policy and infrastructure, economically balanced, socially, and environmentally sustainable and rely on mobility-dedicated assisting features. Further research is proposed on (1) adapting these results to the legal, social, economic, and environmental contexts and (2) the ability of MaaS scenarios to answer the collected dimensions. This research is crucial to determine the areas of focus of a stakeholder-designed transportation system and to frame them in the mobility ecosystem, both individually and interlinked. Furthermore, its originality lies in (1) the application of this methodology to collect, analyse, and define a set of mobility investment priorities, and (2) the recognition of the relevant stakeholders in mobility considering their diverse perspectives and needs.

Transport, Behaviour and Society

The Psychologist January/February 2023: Early Career Researchers: Our world, our challenges, our future.

The British Psychological Society
Cohort: Cohort 1
Date: 03 01 2023

Catherine Naughtie was part of a team of Early Career Researchers (ECRs) based at the University of Bath who had the opportunity to be guest editors for a special issue The Psychologist, Early career researchers: Our world, our challenges, our future.

This issue is based around the theme: ‘The world we have versus the world we need: What challenges do ECRs currently face, and how could addressing them change our future?’. This edition is split into three separate parts, each of which reflect a different element of the theme.

Digital Systems, Optimisation and Integration

Freevalve: Control and Optimization of Fully Variable Valvetrain-enabled Combustion Strategies for Steady-state Part Load Performance and Transient Rise Times

SAE World Congress 2023: Combustion Control and Optimization
Student(s): Abdu Elmagdoub
Cohort: Cohort 2
Date: 14 01 2023

As part of research completed in his first year of PhD, the published work addresses industrial concerns relating the use of fully variable valvetrain (FVVT) technologies in ICEs for part load and transient performance. Adopting a data-based approach, together with his industry and academic partners Koenigsegg, Freevalve, and KAUST, Abdu concluded optimal FVVT-enabled valve strategies targeting maximum scavenging and optimized EGR rates for maximum fuel conversion efficiency and minimal brake specific fuel consumption. The study then goes on to explore the benefits of integrated FVVT technologies in turbocharged vehicles for transient rise times and how the technology assists in minimization of turbo lag and improvement of drivability. Abdu has been invited to present the published work at WCX SAE World Congress Experience, taking place in Detroit, MI, USA in April of 2023.

Digital Systems, Optimisation and Integration

Freevalve: A Comparative GWP Life Cycle Assessment of E-fuel Fully Variable Valvetrain-equipped Hybrid Electric Vehicles and Battery Electric Vehicles

SAE World Congress 2023: Lifecycle Assessment
Student(s): Abdu Elmagdoub
Cohort: Cohort 2
Date: 14 01 2023

In collaboration with our second cohort AAPS CDT student, Joris Simaitis, Abdu authored a Lifecycle Assessment (LCA) paper that has recently been published by SAE International for WCX SAE World Congress Experience 2023 taking place in Detroit, MI, USA. The work presents a comparative global warming potential (GWP) LCA case between a DAC efuel FVVT-equipped hybrid electric vehicle (HEV) and a battery electric vehicle (BEV) for a lifecycle of 150,000 km on two different grid options (a) global average mix and (b) renewable mix. The study uses standardized and peer reviewed LCA database, Ecoinvent, and professional open-source sustainability and LCA footprint modelling software OpenLCA. They found that a net reduction of up to 55% in favour of the DAC efuel FVVT-equipped HEV is evident. The comparison is a first of its kind in the published literature domain, setting a benchmark for DAC efuel FVVT-equipped HEVs in future comparative LCA investigations. Both students have been invited to attend the conference and are due to present the published work.

Transport Policy & Economics

The influence of inclement weather on electric bus efficiency: Evidence from a developed European network

Case Studies on Transport Policy
Student(s): Jac McCluskey
Cohort: Cohort 3
Date: 03 03 2023

Following his internship with the Institute for Policy Research (IPR), Jac co-authored a paper which investigated the impact of inclement weather on the service stability, efficiency, and feasibility of mass-transit bus operations delivered by fully electrified fleets. The objective was to provide easy to interpret results from a real-world case study that would reduce some of the uncertainty operators face when decarbonising their fleets. The regression results suggest that higher wind speeds and lower temperatures positively correlate with energy consumption and negatively correlate with the total energy regeneration rate. This effect is especially pronounced at freezing temperatures. The implication of these results is that through their impact on energy consumption and vehicle range, weather effects will influence the profitability of fleet electrification as well as the optimal fleet size, charging infrastructure, and route schedule.

Sustainability and Low Carbon Transition

Review and meta-analysis of recent life cycle assessments of hydrogen production

ScienceDirect
Student(s): Julian Wilkinson
Cohort: Cohort 2
Date: 07 04 2023

Hydrogen (H2) is increasingly valued as a carbon-free energy carrier, however, the environmental impact of the different methods for hydrogen production are sometimes overlooked. This article provides a comprehensive overview of the environmental impacts and costs of a diverse range of methods for producing hydrogen. Ninety-nine life cycle assessments (LCAs) published between 2015 and 2022 are categorised by geography, production method, energy source, goal and scope, and compared by data sources and methodology. A meta-analysis of methodological choices is used to identify a subset of mutually comparable studies whose results are then compared, initially by global warming potential (GWP), then low-GWP scenarios are compared by other indicators. The results show that the lowest GWP is achieved by methods that are currently more expensive (∼US $4–9/kg H2) compared to the dominant methods of producing hydrogen from fossil fuels (∼US $1–2/kg H2). The research finds that data are currently limited for comparing environmental indicators other than GWP, such as terrestrial acidification or freshwater eutrophication. Recommendations are made for future LCAs of hydrogen production.

Transport, Behaviour and Society

Quantifying the Importance of Socio-Demographic, Travel-Related, and Psychological Predictors of Public Acceptability of Low Emission Zones

Journal of Environmental Psychology
Student(s): Lois Player
Cohort: Cohort 2
Date: 24 05 2023

As ambient air pollution increases, governments are imposing traffic management strategies to improve air quality. A common strategy is the implementation of Low Emission Zones (LEZs), which have generated considerable public debate. Nonetheless, little research has explored which factors determine their public acceptability. Previous empirical studies have also typically lacked power for regression analyses and have not determined the relative importance of different predictors. After conducting a large online survey in a UK city, well-powered multiple regression and dominance analyses demonstrated that psychological factors, such as environmental moral obligation, were the most important predictors of LEZ acceptability. However, travel-related and socio-demographic factors, such as distance lived from the LEZ and having dependent children, were also unique and important predictors. Overall, we argue that, whilst psychological factors are important, travel-related and socio-demographic barriers must not be overlooked during LEZ implementation.

Sustainability and Low Carbon Transition

Are future recycling benefits misleading? Prospective life cycle assessment of lithium-ion batteries

Journal of Industrial Ecology
Student(s): Joris Simaitis
Cohort: Cohort 2
Date: 22 06 2023

Life cycle assessment (LCA) quantifies the whole-life environmental impacts of products and is essential for helping policymakers and manufacturers transition toward sustainable practices. However, typical LCA estimates future recycling benefits as if it happens today. For long-lived products such as lithium-ion batteries, this may be misleading since there is a considerable time gap between production and recycling. To explore this temporal mismatch problem, we apply future electricity scenarios from an integrated assessment model—IMAGE—using “premise” in Brightway2 to conduct a prospective LCA (pLCA) on the global warming potential of six battery chemistries and four recycling routes. We find that by 2050, electricity decarbonization under an RCP2.6 scenario mitigates production impacts by 57%, so to reach zero-carbon batteries it is important to decarbonize upstream heat, fuels, and direct emissions. For the best battery recycling case, data for 2020 gives a net recycling benefit of −22 kg CO2e kWh−1 which reduces the net impact of production and recycling from 71 to 49 kg CO2e kWh−1. However, for recycling in 2040 with decarbonized electricity, net recycling benefits would be nearly 75% lower (−6 kg CO2e kWh−1), giving a net impact of 65 kg CO2e kWh−1. This is because materials recycled in the future substitute lower-impact processes due to expected electricity decarbonization. Hence, more focus should be placed on mitigating production impacts today instead of relying on future recycling. These findings demonstrate the importance of pLCA in tackling problems such as temporal mismatch that are difficult to capture in typical LCA.

Propulsion Electrification

Real-Time Temperature Prediction of Electric Machines Using Machine Learning with Physically Informed Features

Energy and AI
Student(s): Ryan Hughes
Cohort: Cohort 2
Date: 13 07 2023

Accurate estimation of the internal temperatures of electric machines is critical to increasing their power density and reliability since key temperatures, such as magnet temperature, are often difficult to measure. This work presents a new machine learning based modelling approach, incorporating novel physically informed feature engineering, which achieves best-in-class accuracy and reduced training time. The different features introduced are proportional to sources of machine losses and require no prior knowledge of the machine, hence the models are completely data driven. Evaluation using a standard experimental dataset shows that modelling errors can be reduced by up to 82.5%, resulting in the lowest mean squared error recorded in the literature of 2.40 K 2. Additionally, models can be trained with less training data and have lower sensitivity to data quality. Specifically, it was possible to train a loss enhanced multilayer perceptron model to a mean squared error <5 K 2 with 90 h of training data, and an enhanced ordinary least squares model with just 60 h to the same criteria. The inference time of the model can be 1–2 orders of magnitude faster than competing models and requires no time to optimise hyperparameters, compared to weeks or months for other state-of-the-art prediction methods. These results are highly important for enabling low-cost real-time temperature monitoring of electric machines to improve operational efficiency, safety, reliability, and power density.

Transport, Behaviour and Society

The 19-Item Environmental Knowledge Test (EKT-19): A short, psychometrically robust measure of environmental knowledge

Heliyon
Student(s): Lois Player
Cohort: Cohort 2
Date: 09 08 2023

Environmental knowledge is considered an important pre-cursor to pro-environmental behaviour. Though several tools have been designed to measure environmental knowledge, there remains no concise, psychometrically grounded measure. We validated an existing measure in a British sample, confirming that it had good one- and three-factor structures in line with previous literature. For the first time in this field, we built upon previous Classical Test Theory approaches and used discrimination values derived from Item Response Theory to select the best items, resulting in the 19-Item Environmental Knowledge Test (EKT-19). This measure retained a clear factor structure and had moderate-to-good internal reliability, indicating that it is a parsimonious and psychometrically robust measure for the assessment of overall and specific types of environmental knowledge. The theoretical implications and real-world applications of this measure are discussed.

Sustainability and Low Carbon Transition

Pioneering Net Zero Carbon Construction Policy in Bath & North East Somerset: Investigating the industry’s response to the introduction of novel planning policies

University of Bath
Student(s): Joris Simaitis
Cohort: Cohort 2
Date: 20 10 2023

A pilot study run by the University of Bath in partnership with Bath & North East Somerset Council, Chapter2 Architects and the South West Net Zero Hub

Propulsion Electrification

Analysis of Long-term Indicators in the British Balancing Market

IEEE Transactions on Power Systems
Student(s): Isaac Flower
Cohort: Cohort 2
Date: 26 07 2023

Proactive participation of uncertain renewable generation in the day-ahead (DA) wholesale market effectively reduces the system marginal price and carbon emissions, whilst significantly increasing the volumes of real-time balancing mechanism prices to ensure system security and stability. To solve the conflicting interests over the two timescales, this paper: 1) proposes a novel hierarchical optimization model to align with the actual operation paradigms of the hierarchical market, whereby the capacity allocation matrix is adopted to coordinate the DA and balancing markets; 2) mathematically formulates and quantitatively analyses the long-term driving factors of balancing actions, enabling system operators (SOs) to design efficient and well-functioning market structures to meet economic and environmental targets; 3) empowers renewable generating units and flexible loads to participate in the balancing market (BM) as &#x2018;active&#x2019; actors and enforces the non-discriminatory provision of balancing services. The performance of the proposed model is validated on a modified IEEE 39-bus power system and a reduced GB network. Results reveal that with effective resource allocation in different timescales of the hierarchical market, the drop speed of balancing costs soars while the intermittent generation climbs. The proposed methodology enables SOs to make the most of all resources available in the market and balance the system flexibly and economically. It thus safeguards the climate mitigation pathways against the risks of substantially higher balancing costs.

Digital Systems, Optimisation and Integration

Predictive control optimization of a holistic Thermal Management System for a Battery Electric Vehicle using Dynamic Programming

Fisita World Congress - International Barcelona Convention Centre, Barcelona, Spain
Student(s): Charlie Gaylard
Cohort: Cohort 2
Date: 27 09 2023
As the adoption and development of battery electric vehicles (BEV) increases globally with the aim to eliminate tail-pipe emissions of the incoming generation of vehicles, the automotive industry faces new challenges to maintain cost and performance parity of the new battery vehicles with their internal combustion engine (ICE) counterparts. These challenges include the temperature sensitivity of powertrain components, user range anxiety, bottlenecks in charging infrastructure and crucially, the additional burden of auxiliary consumers such as climate control.

Yet, these challenges coincide with a new era of high-speed communication and connectivity which pose many opportunities for connected vehicles to solve and optimize complex control problems. Intelligent control solutions based on predicted knowledge of future driving conditions can be used to reduce the overall energy consumption of a vehicle journey, increasing potential range, and allowing the use of smaller, cheaper powertrain components. Furthermore, such intelligent control solutions when applied to the thermal management system could help reduce stress on thermally sensitive components, increasing their efficiency and lifespan.

We capitalized on a proposed holistic BEV thermal management system model developed at AVL to study the potential gains in energy consumption if using connected control optimization. The system model utilizes the idea that three key domains can be interchangeably defined as ‘heat sinks’ or ‘heat rejectors’, thus allowing for the transfer of excess heat energy from where it is not required to where it is. The three key domains include the battery, electric machine, and cabin air temperature. Depending on the state of each domain and the ambient conditions, heat energy can be transferred via heat pumps, allowing for holistic control of these three thermal states. This thermal management system operates categorically and is made of up of eight pre-engineering control modes which determine how heat energy is transferred around the vehicle. For heating purposes, if sufficient heat energy is not present in the system or atmospheric conditions, the electric heater is used, drawing energy from the battery.

Selecting which mode to use and when poses a complex control problem, but if implemented well, can reduce battery energy consumption while ensuring passenger comfort. Future knowledge of the journey makes it possible to model the predicted state conditions and apply optimization techniques to select the most suitable sequence of control modes for a given journey. This paper evaluates the application of Dynamic Programming (DP) for use with this categorical type of control system. The DP algorithm views the problem as a whole, therefore providing a global optimum solution based on a full journey, as opposed to a rule-based system which makes decisions based only on current and past state conditions. DP is computationally intensive and is therefore typically applied as an “offline” optimizer from which to benchmark, thus, this research acts as a precursor to the development of a real-time optimized controller. As the DP results identify the best possible system gains, these will be used as a benchmark when implementing an online optimized controller, and to assess the level of investment appropriate considering the available gains.

This study has used a thermal management model and integrated this with the highly optimized Dynamic Programming MATLAB toolbox, “DPM”, developed at ETH Zurich by Sundstrom, O et al. Initial simulations over the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) resulted in a maximum improvement in cold ambient conditions where the powertrain components are at their least efficient. The potential gains diminish at higher ambient temperatures as the powertrain components are closer to their operating windows. The results of this study provide a valuable insight into the optimization of the thermal management of a BEV which is potentially critical for their success as a long-term viable alternative to ICE powered vehicles.
Digital Systems, Optimisation and Integration

On Integration of MBSE and Simulation for Evaluation of Complex, Quantitative, Temporal Key Performance Indicators

ASEC 2023
Student(s): Lukas Macha
Cohort: Cohort 2
Date: 22 11 2023

Engineering of today’s complex automotive systems relies on heterogeneous, model-based development toolchains to compute various performance measures to demonstrate product quality and support decision making. Despite advances in System Modelling and simulation, their integration often hits a bottleneck due to cumbersome, expensive and error-prone process of manual transformation of information regarding verification criteria from authoritative System Models into domain specific simulation toolchains. To overcome these obstacles, we introduce a novel methodology that facilitates integration of System Models, built using System Modelling Language (SysML), with simulation, to enable evaluation of quantitative Key Performance Indicators (KPIs) at every system life cycle stage. This is demonstrated in a five-step process using an automotive Adaptive Cruise Control (ACC) application. First, we develop a comprehensive SysML model to analyse the system in its intended context. Second, we extract the KPIs from system requirements written in natural language and formalize them in Signal Temporal Logic (STL) to define constraint parameters. Third, we capture the atomic propositions of STL KPIs to establish traceability between constraint parameters, system properties and interfaces. Fourth, we establish correspondence between the System Architecture and domain-specific models. Fifth, simulation capabilities are leveraged to evaluate temporal, quantitative KPIs, providing insight into the system performance in achieving the desired task. This novel integration eliminates the need for manual transformation of information from System Models to simulation toolchains, reduces opportunity for error, and enhances scalability to streamline the development process of automotive systems using Model Based Systems Engineering (MBSE).

Digital Systems, Optimisation and Integration

Non-contact Heart Rate Monitoring: A Comparative Study of Computer Vision and Radar Approaches

Springer Nature Switzerland
Student(s): Gengqian Yang
Cohort: Cohort 3
Date: 17 07 2023
Transport, Behaviour and Society

Integrating three diverse perspectives into the proposed role for cooperation in sustainable transport policymaking: a reply to commentaries on ‘From “I” to “we”: an exploration of how theories of cooperation might inform policymaking around sustainable travel behaviour’ by Brendan Donegan et al

Global Discourse
Student(s): Pete Dyson
Cohort: Cohort 4
Date: 10 11 2023

We are grateful to the three commentators on our original article (Donegan et al, 2023), particularly for the diversity of perspectives. Consistent with the global nature of this journal, commentary was derived from: the UK (Professor Sarah Sharples, who wears two UK `hats’, as a Professor of Human Factors at the University of Nottingham and Chief Scientific Adviser for the UK Government’s Department of Transport); Israel (Professor Ben-Elia at Ben-Gurion University of the Negev); and Japan (Professor Fujii at Kyoto University). We are grateful for their engagement and can offer six points of reply to build on their contributions.

Transport Policy & Economics

Enabling green choices for net zero

UK Parliament POST, POSTNote 714
Student(s): Ellie Smallwood
Cohort: Cohort 3
Date: 19 02 2024

This POSTnote by Ellie Smallwood summarises the challenges and options for enabling and encouraging of low-carbon actions by individuals in sectors with the highest emissions, which from the research undertaken as part of her 3 month UKRI Internship with POST. 

© Copyright 2021 AAPS CDT, Centre for Doctoral Training in Advanced Automotive Propulsion Systems at the University of Bath