A holistic analysis method to assess the controllability of commercial buildings and their systems

This paper describes a novel design process for advanced MIMO (multiple inputs and multiple outputs) control system design and simulation for buildings. The paper describes the knowledge transfer from high technology disciplines such as aerospace flight control systems and the space industry to establish a three-step modelling and design process. In step 1, simplified, but holistic nonlinear and linearised dynamic models of the building and its systems is derived. This model is used to analyse the controllability of the building. In step 2, further synthesis of this model leads to the correct topology of the control system design. This is proved through the use of simulation using the simple building model. In step 3, the controller design is proved using a fully detailed building simulation such as ESP-r that acts as a type of virtual prototype of the building. The conclusions show that this design approach can help in the design of superior and more complex control systems especially for buildings designed with a Climate Adaptive Building (CAB) philosophy where many control inputs and outputs are used to control the building's temperature, concentration of CO2, humidity and lighting levels

Non-linear autopilot design using the philosophy of variable transient response

The novel non-linear controller design methodology of Variable Transient Response (VTR) is presented in this research. The performance of VTR is compared to that of successful non-linear controller designs (such as Robust Inverse Dynamics Estimation and a traditional autopilot design) by application to a non-linear missile model. The simulated results of this application demonstrate that the inclusion of VTR into the RIDE design results in a 50% improvement in response time and 100% improvement in settling time whilst achieving stable and accurate tracking of a command input. Analysis demonstrates that VTR dynamically alters the system's damping, resulting in a non-linear response. The system stability is analysed during actuator saturation using non-linear stability criteria. The results of this analysis show that the inclusion of VTR into the RIDE design does not compromise non-linear system stability

Renewable power for lean desktops in media applications

An integration of solar microgeneration to supply a low-power IT desktop, using the Power over Ethernet standards IEEE 802.3af/at as a low power distribution network avoiding transformer losses from DC generation to mains power AC and back to low-voltage DC and hence maximising efficiency. The resulting design points to applications in media technology where reducing grid power consumption is critical for improving sustainability, or where there are supply constraints, and indicates new directions in how we manage and consume power for IT devices

A comparison of the UK Standard Assessment Procedure and detailed simulation of solar energy systems for dwellings

The drive to reduce worldwide Carbon Emissions directly associated with dwellings and to achieve a zero carbon home dictates that Renewable Energy Technologies will have an increasingly large role in the built environment. Created by the Building Research Establishment (BRE), the Standard Assessment Procedure (SAP) is the UK Government's approved methodology for assessing the energy ratings of dwellings. This paper presents an evaluation of the advantage given to SAP ratings by the domestic installation of typical Photovoltaic (PV) and Solar Domestic Hot Water (SDHW) systems in the UK. Comparable PV and SDHW systems will also be simulated with more detailed modelling packages. Results suggest that calculation variances can exist between the SAP methodology and detailed simulation methods, especially for higher performance systems that deviate from the default efficiency parameters

Hybrid Heat Pump for Micro Heat Network

Achieving nearly zero carbon heating continues to be identified by UK government analysis as an important feature of any lowest cost pathway to reducing greenhouse gas emissions. Heat currently accounts for 48% of UK energy consumption and approximately one third of UK’s greenhouse gas emissions. Heat Networks are being promoted by UK investment policies as one means of supporting hybrid heat pump based solutions. To this effect the RISE (Renewable Integrated and Sustainable Electric) heating system project is investigating how an all-electric heating sourceshybrid configuration could play a key role in long-term decarbonisation of heat. For the purposes of this study, hybrid systems are defined as systems combining the technologies of an electric driven air source heat pump, electric powered thermal storage, a thermal vessel and micro-heat network as an integrated system. This hybrid strategy allows for the system to store up energy during periods of low electricity demand from the national grid, turning it into a dynamic supply of low cost heat which is utilized only when required. Currently a prototype of such a system is being tested in a modern house integrated with advanced controls and sensors. This paper presents the virtual performance analysis of the system and its design for a micro heat network with multiple dwelling units. The results show that the RISE system is controllable and can reduce carbon emissions whilst being competitive in running costs with a conventional gas boiler heating system

Design and specification of building integrated DC electricity networks

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Adoption of millions of small energy efficient, low power digital and DC appliances at home and at work is resulting in a significant and fast growing fraction of a building's electricity actually consumed in low voltage DC form. Building integrated energy systems featuring renewable photovoltaics are also increasingly attractive as part of an overall electricity and emissions reduction strategy. This paper details design and specification of a novel system level method of matching building integrated photovoltaic electricity generation with local low voltage DC appliances in office and other ICT intensive environments such as schools. The chosen scenario considers load components consisting of a diverse range of modern low power ICT and DC appliances, networked and powered by industry certified smart DC distribution technologies. Energy supply to the converged DC, IT and ICT network is described as featuring a roof-mounted or other on-site photovoltaic array in combination with conventional supply from the local grid infrastructure. The direct and strategic benefits of smart DC infrastructures are highlighted as the enabling technology for optimal demand reduction through fully integrated energy management of DC systems in buildings

Comparative Performance Modelling of Heat Pump based Heating Systems using Dynamic Carbon Intensity

11th IET International Conference (APSCOM 2018) on Advances in Power System Control, Operation and Management, 2018Modern buildings and homes utilise multiple systems for energy generation, supply and storage in order to maintain occupant comfort, reduce operating costs and CO2 emissions. In recent times electricity generation and supply network (UK National Grid) have had to manage variable supply from renewable sources such as wind turbines and photovoltaics. This resulting supply mixture has a dynamic profile at intermittent times. To manage excess supply, the options are either to reduce the generation by power stations/renewables or reinforce the power infrastructure with storage capability. This has given rise to calls for electrification of services in streamlining the supply profile through intelligent demand response such as electric heating and vehicles. Furthermore, due to zero carbon energy sources with dynamic supply profile, the carbon intensity is no longer constant. This impacts the seasonal CO2 emissions calculations and also the design and performance of electrical powered heat pump based heating systems. The RISE (Renewable Integrated Sustainable Electric) heating system was developed (funded by the UK Research and Innovation), where an electrical powered Heat pump is combined with electric thermal storage allowing low cost and low carbon electricity to be utilised. For such a system more realistic performance analysis requires dynamic carbon intensity calculations to assess impact on its ability to maintain comfort, low operating costs and low carbon emissions. The paper builds upon previously published research on the RISE system comparing with domestic Gas Condensing Boiler (GCB) using static carbon calculations. This paper presents a comparison between the RISE system and standard domestic electrical powered Air Source Heat Pump (ASHP) when using static and dynamic carbon intensity profiles. The Inverse Dynamics based Energy Assessment and Simulation (IDEAS) framework is utilised for modelling and dynamic simulation of building and heating system, operating cost and estimation of annual emissions based on half hourly (HH) dynamic CO2 intensity figures rather than annual average. The results show that with dynamic carbon intensity calculations, both electric heat pump based heating systems, RISE and ASHP show a significant increase (>15%) in carbon emissions for space heating. The results also show that whilst the RISE system’s thermal storage helps to reduce running costs using a time of use tariff (TOU), it only provides a small benefit in carbon emissions

Pre-hospital notification is associated with improved stroke thrombolysis timing

Peer reviewedPublisher PD

Assessment of Multi-Domain Energy Systems Modelling Methods

Emissions are a consequence of electricity generation. A major option for low carbon generation, local energy systems featuring Combined Heat and Power with solar PV (CHPV) has significant potential to increase energy performance, increase resilience, and offer greater control of local energy prices while complementing the UK’s emissions standards and targets. Recent advances in dynamic modelling and simulation of buildings and clusters of buildings using the IDEAS framework have successfully validated a novel multi-vector (simultaneous) control of both heat and electricity approach to integrating the wide range of primary and secondary plant typical of local energy systems designs including CHP, solar PV, gas boilers, absorption chillers and thermal energy storage, and associated electrical and hot water networks, all operating under a single unified control strategy. Results from this work indicate through simulation that integrated control of thermal storage can have a pivotal role in optimizing system performance well beyond the present expectations. Environmental impact analysis and reporting of all energy systems including CHPV LES presently employ a static annual average carbon emissions intensity for grid supplied electricity. This paper focuses on establishing and validating CHPV environmental performance against conventional emissions values and assessment benchmarks to analyze emissions performance without and with an active thermal store in a notional group of non-domestic buildings. Results of this analysis are presented and discussed in context of performance validation and quantifying the reduced environmental impact of CHPV systems with active energy storage in comparison with conventional LES designs

Design and specification of building integrated DC electricity networks

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Adoption of millions of small energy efficient, low power digital and DC appliances at home and at work is resulting in a significant and fast growing fraction of a building's electricity actually consumed in low voltage DC form. Building integrated energy systems featuring renewable photovoltaics are also increasingly attractive as part of an overall electricity and emissions reduction strategy. This paper details design and specification of a novel system level method of matching building integrated photovoltaic electricity generation with local low voltage DC appliances in office and other ICT intensive environments such as schools. The chosen scenario considers load components consisting of a diverse range of modern low power ICT and DC appliances, networked and powered by industry certified smart DC distribution technologies. Energy supply to the converged DC, IT and ICT network is described as featuring a roof-mounted or other on-site photovoltaic array in combination with conventional supply from the local grid infrastructure. The direct and strategic benefits of smart DC infrastructures are highlighted as the enabling technology for optimal demand reduction through fully integrated energy management of DC systems in buildings