Functions of fuzzy logic based controllers used in smart building

The main aim of this study is to support design and development processes of advanced fuzzy-logic-based controller for smart buildings e.g., heating, ventilation and air conditioning, heating, ventilation and air conditioning (HVAC) and indoor lighting control systems. Moreover, the proposed methodology can be used to assess systems energy and environmental performances, also compare energy usages of fuzzy control systems with the performances of conventional on/off and proportional integral derivative controller (PID). The main objective and purpose of using fuzzy-logic-based model and control is to precisely control indoor thermal comfort e.g., temperature, humidity, air quality, air velocity, thermal comfort, and energy balance. Moreover, this article present and highlight mathematical models of indoor temperature and humidity transfer matrix, uncertainties of users’ comfort preference set-points and a fuzzy algorithm

System Design: A Novel, Project-Based Course Connecting the Dots of the Electrical Engineering Curriculum

The four year curriculum of the Electrical Engineering program includes a fairly diverse set of classes covering topics including electronics, electromagnetics, signal processing, power & energy, digital systems, as well as communication and control systems. While these topics constitute the core components in the technical education of a future electrical engineer, a major missing component is the holistic, system understanding of these individual topics. This paper describes a class addressing the integration of the technical topics in addition to defining the overall architecture, the modularity of complex systems, as well as the interfaces between the different components to satisfy design requirements. The new class is a project-based, one credit-hour class with a single weekly meeting in a laboratory environment. The paper describes the assigned projects as well as their proposed solutions. The paper also includes assessment data including student feedback from the first class offering. Assessment shows a great student enthusiasm towards the class. It also shows that the class improved the student\u27s conceptual knowledge, knowledge retention, and problem solving skills

Design of type-1 servo controller for grid voltage modulated direct-power control of single-phase grid-connected PV inverter

This paper presents direct control of active and reactive power using grid voltage modulation for single-phase grid-connected photovoltaic inverter. A design of type-1 servo system based on pole-placement method is proposed to control the power flow using a simplified multiple-input multiple-output (MIMO) model of the system. Phase-locked loop (PLL) with a quarter cycle time delay is used to estimate the grid phase angle for the purpose of performing the stationary and synchronous reference frame transformation. Unipolar pulse width modulation (PWM) technique is used to control a single-phase inverter with 2.7 KVA capacity connected to the photovoltaic system. The proposed controller can simply be tuned using minimum number of controller gains to achieve the transient and steady-state performance requirements. The proposed system, was capable of operating for a wide range of solar irradiance levels with a power factor in the range of 0.95 (leading/lagging), for the reactive power compensation purposes

Direct control of active and reactive power for a grid-connected single-phase photovoltaic inverter

This paper presents a single-phase grid-connected photovoltaic system with direct control of active and reactive power through a power management system of a Photovoltaic inverter. The proposed control algorithm is designed to allow maximum utilization of the inverter’s available KVA capacity while maintaining grid power factor and current total harmonic distortion (THD) requirements within the grid standards. To reduce the complexity and improve the efficiency of the system, two independent PI controllers are implemented to control single-phase unipolar PWM voltage source inverter. One controller is used to control the power angle, and hence the active power flow, while the other controller is used to control the reactive power, and consequently the power factor by adjusting the voltage modulation index of the inverter. The proposed system is modelled and simulated using MATLAB/Simulink. The PV inverter has been examined while being simultaneously connected to grid and local load. Results obtained showed the ability of the PV inverter to manage the active and reactive power flow at, and below rated levels of solar irradiances; resulting in an increased inverter utilization factor, and enhanced power quality. The proposed system, was capable of operating at power factors in the range of 0.9 lead or lag for reactive power compensation purposes and delivered its power at a wide range of solar irradiance variations

The impact of COVID-19 and its terminology learning strategies on EFL learners’ vocabulary repertoire

COVID-19 pandemic is an unprecedented crisis worldwide posing many linguistic challenges including understanding and learning new related terminology. This study explores the impact of the COVID-19 pandemic and its terminology learning strategies on EFL learners' vocabulary acquisition, particularly in Jordan. A triangulated approach was employed for collecting data including interviews, tests and a questionnaire distributed to 100 EFL learners at a Jordanian university. The qualitative and quantitative analysis of the data showed a positive influence of the COVID-19 pandemic and its terminology strategies on EFL learners' knowledge of vocabulary. It also revealed that the participants were “medium” users of cognitive, determination, and social strategies and “high” users of metacognitive and memory vocabulary learning strategies for acquiring COVID-19 associated terminology. The analysis of the tests demonstrated that the COVID-19 and its Vocabulary Language Strategies (VLSs) have a significant positive impact on students' vocabulary knowledge size. Thus, it verified the effectiveness of the reported strategies for acquiring COVID-19 terminology. The learners' vocabulary repertoire has been enriched with new COVID-19 related vocabulary such as quarantine, lockdown, incubation, pandemic, contagious, outbreak, epidemic, pathology, infectious, asymptomatic, covidiot, pneumonia, anorexia, etc. The findings highlighted the importance of employing efficient strategies for investing newly emerging contexts to cultivate learners’ vocabulary repertoire. This study contributes to the area of language acquisition through extensive illustrations of COVID-19 associated lexicon and the intensified-in use associated vocabulary learning strategies. The study concludes with some pedagogical implications and recommendations for further research