Hiri eta Komunitate Adimenduak Erasmus Mundus Masterra (SMACCs);;Máster Erasmus Mundus en Comunidades y Ciudades Inteligentes (SMACCs)http://hdl.handle.net/10810/524652024-03-29T10:01:49Z2024-03-29T10:01:49ZDynamic and Transient Analysis of LVRT Augmented Grid Tied DFIG based Wind TurbineHossain, Md Sajidhttp://hdl.handle.net/10810/579702022-10-11T18:03:59Z2022-07-11T00:00:00ZDynamic and Transient Analysis of LVRT Augmented Grid Tied DFIG based Wind Turbine
Hossain, Md Sajid
This thesis aims to present Low Voltage Ride Through (LVRT) augmentation of the gridtied Doubly Fed Induction Generator (DFIG) based wind turbine. Voltage stability is a critical grid code criterion that must be strictly adhered. A substantial voltage drop happens during a fault or network disruption situation, which must be restored as quickly as possible. According to modern grid code standards, 90 percent of the voltage must be restored to pre-fault levels in 1500 milliseconds. As a result, both dynamic and transient assessments are performed to evaluate the intended power system's LVRT capabilities. In this study, fault analysis including the most severe 3LG fault under transient conditions has been examined in order to evaluate the tuned PI controller scheme and resilience of the developed power system model. PSCAD/EMTDC® v4.5 tool has been used extensively to develop the DFIG wind turbine aerodynamic model, DFIG control scheme and power system model analysis. Simulation results show that tuned Proportional Plus Integral (PI) controllers effectively augment the LVRT functionality by injecting sufficient reactive power into the grid during fault or network disturbance scenarios.
2022-07-11T00:00:00ZOptimal design of HVAC systems for the design of nearly Zero Energy Buildings under different climate conditionsZeyad, Mohammadhttp://hdl.handle.net/10810/579692022-10-11T18:20:09Z2022-09-21T00:00:00ZOptimal design of HVAC systems for the design of nearly Zero Energy Buildings under different climate conditions
Zeyad, Mohammad
This master thesis aims to develop a methodology to identify the optimal operation of different HVAC system configurations for different climate conditions and building typologies. To reach the objective, the work is carried out in three main steps using dedicated tools (DesignBuilder, EnergyPlus, and eppy script (python language)) and running co-simulation. In addition, the nZEB standard established by the most recent edition of the Spanish Technical Building Code is addressed in this study through a parametric optimization study of a reference building. The effectiveness of this legislation is evaluated in terms of its capacity to disseminate the idea of building energy cost optimization and reduce the annual energy consumption in the residential sector. To this end, a reference building was designed and multiple HVAC designs were evaluated using DesignBuilder building energy simulation software and found the best optimization of HVAC solutions through EnergyPlus and eppy. In total, a set of 30 alternative scenarios was established and parametrically evaluated for 5 cities representing the 5 climatic zones of inland Spain (Bilbao, Burgos, Seville, Madrid, and Almeria) resulting in 150 simulations. The results were evaluated utilizing annual energy consumption (electricity, natural gas, and other fuels) values concerning the calibration of set point manager temperature (heating), obtaining the cost-optimal and minimum consumption levels of annual energy. It is worth mentioning that this study is mainly concentrating on the Energy Supply System (ESS), where the Energy Saving Measure (ESM) is kept unchanged, which should be reviewed in future updates.
2022-09-21T00:00:00ZA multifaceted analysis of COVID-19 propagation in confined spaces: a techno-economic assessment of ventilation, heating, and renewables integrationAbdulrahman, Mohammedhttp://hdl.handle.net/10810/524742022-10-11T18:20:09Z2021-06-01T00:00:00ZA multifaceted analysis of COVID-19 propagation in confined spaces: a techno-economic assessment of ventilation, heating, and renewables integration
Abdulrahman, Mohammed
The outbreak of novel coronavirus disease 2019 (COVID19) has spread rapidly, affecting nearly all countries and territories around the globe, impacting every aspect of human life. Governments and various organizations worldwide have issued mitigation measures to counteract COVID-19 virus propagations, whether in indoor spaces or outdoors. Although the underlying uncertainty concerning COVID-19 transmission details, most international organizations such as WHO, ECDC, ASHRAE, REHVA, and CIBSE agree on the important role of ventilation to minimize the causes and reduce the viability of SARS-CoV-2 in confined spaces. Given that natural ventilation is variable, which depends on the intermittent wind source, mechanical ventilation systems provide stable airflow rates that ensure reliability and adequacy to meet the minimum ventilation rates for building users in a controlled environment. Thus, a paradigm shift in the mechanical ventilation system is needed to steer the focus from the predominant energy efficient space-based design to occupant-based design. This study will discuss the cost-related effects to ensure stable and adequate ventilation by setting up ventilation scenarios with parameters derived from the recommendations published in recent guidelines focusing on HVAC operations. A working methodology is applied to a case study on two zones, an office, and a nursery. The results show that maintaining a minimum of five and seven air changes per hour for office and nursery, respectively, with proper indoor air distribution can reduce the risk of infection by more than half while ensuring an economic balance between ventilation costs and infection risk. Additionally, the study suggests using photovoltaics installations to power ventilation rates higher than five air changes per hour which can save at least forty-five tons of CO2 while reaching a payback period in thirteen years. Based on the achieved results, the paper presents recommendations to operate the two zones’ ventilation, space heating, and photovoltaics cost-effectively while ensuring COVID-19 probability of infection reduction.
vii, 73 p., xii
2021-06-01T00:00:00ZThe Impact of Occupant Behaviour on Energy Consumption at Resi-dential BuildingsKarakus, Rukenhttp://hdl.handle.net/10810/524712022-08-04T12:00:08Z2021-06-01T00:00:00ZThe Impact of Occupant Behaviour on Energy Consumption at Resi-dential Buildings
Karakus, Ruken
Buildings are responsible for 40 percent of energy consumption in cities and cities are responsible for 60 to 80 percent of the total energy consumption in the world. Besides energy consumption in the industrial market which has complex dynamics to investigate, residential buildings have a big piece of the pie in this share. To avoid the catastrophic effects of climate change and depletion of sources, energy demand and correspondingly energy consumption in cities should be controlled immediately by every energy con-sumer. In this matter, the control of energy demand depends principally on the actions of the users. Evaluating the social science behind energy consumption is not the study area of this research but the impact of adaptive behaviours to control indoor comfort are main objectives. This study goals to examine the effect of occupant behavior through Design-Builder with hypothetical and probabilistic scenarios which are configurations of Occu-pancy, Heating, Cooling, DHW, Equipment and Lighting schedules and setpoints. Three different building typologies from 3 different cities and climates` building energy performance will be analyzed through the combination of two other variables: thermal condition of the buildings and user behavior. The user behaviors are grouped into two as economic and wasteful. In the end, the comparative results of the scenarios were analyzed. The final comparison analysis confirms the assertion of the study that user behavior effects the energy demand directly proportional; wasteful occupant has the highest energy demand while the scenarios based on the Spanish technical code for energy savings has the opti-mal and economic scenarios have the lowest. The analysis of the study leads to an un-touched area of study to enlarge the scale and examine the impact of occupant behavior at low energy districts and cities to prevent the negative effects of increased urban energy consumption.
xiii, 63 p.
2021-06-01T00:00:00Z