Energy consumption optimization for AC drives position control

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Branislav Ftorek ◽  
Milan Saga ◽  
Pavol Orsansky ◽  
Jan Vittek ◽  
Peter Butko
Keyword(s):  
Control System ◽  
Energy Saving ◽  
Energy Savings ◽  
Position Control ◽  
Control Strategies ◽  
Content Type ◽  
Ac Drives ◽  
Energy Demands ◽  
Wide Range ◽  
Energy Consumption Optimization

Purpose The main purpose of this paper is to evaluate the two energy saving position control strategies for AC drives valid for a wide range of boundary conditions including an analysis of their energy expenses. Design/methodology/approach For energy demands analysis, the optimal energy control based on mechanical and electrical losses minimization is compared with the near-optimal one based on symmetrical trapezoidal speed profile. Both control strategies respect prescribed maneuver time and define acceleration profile for preplanned rest-to-rest maneuver. Findings Presented simulations confirm lower total energy expenditures of energy optimal control if compared with near-optimal one, but the differences are only small due to the fact that two energy saving strategies are compared. Research limitations/implications Developed overall control system consisting of energy saving profile generator, pre-compensator and position control system respecting principles of field-oriented control is capable to track precomputed state variables precisely. Practical implications Energy demands of both control strategies are verified and compared to simulations and preliminary experiments. The possibilities of energy savings were confirmed for both control strategies. Originality/value Experimental verification of designed control structure is sufficiently promising and confirmed assumed energy savings.

scholarly journals Energy Near-Optimal Control Strategies for Industrial and Traction Drives with a.c. Motors

2017 ◽  
Vol 2017 ◽  
pp. 1-22 ◽  
Author(s):  
Ján Vittek ◽  
Peter Butko ◽  
Branislav Ftorek ◽  
Pavol Makyš ◽  
Lukáš Gorel
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Energy Savings ◽  
Position Control ◽  
Control Strategies ◽  
Time Profile ◽  
Optimal Controls ◽  
Zero Dynamic ◽  
Loop Dynamics ◽  
Traction Drives

The main contribution of this paper is a new rest-to-rest position control system for use with electric drives employing a.c. motors that is near-optimal with respect to combined electrical and frictional energy waste minimization. The friction has constant, linear, and quadratic components with respect to the rotor speed. The closeness to optimality is assessed by simulation, comparing the energy loss of the new control system with that predicted by computed optimal controls. The application of the near-optimal control system is rendered straightforward by using a symmetrical trapezoidal speed-time profile. This is provided by an energy saving reference position generator whose output is faithfully followed by means of a feedback control law based on forced dynamics control yielding prescribed closed loop dynamics, together with a matched zero dynamic lag precompensator. For load torque consisting of constant, linear, and quadratic components also maneuver time is optimized if it can be chosen arbitrary. Two case studies, one applied to position control of rotational drive and second one applied to train movement, confirm the possibilities of achieving energy savings.

Energy-efficient retrofitting of multi-storey residential buildings

Facilities ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Michael C.P. Sing ◽  
Venus W.C. Chan ◽  
Joseph H.K. Lai ◽  
Jane Matthews
Keyword(s):  
Energy Saving ◽  
Energy Use ◽  
Energy Savings ◽  
Residential Buildings ◽  
Baseline Scenario ◽  
Content Type ◽  
Energy Retrofit ◽  
Energy Demands ◽  
Research Findings

Purpose Sustainable retrofitting of aged buildings plays a significant role in reducing energy demands and greenhouse gas emissions. This study aims to assess the performance and effectiveness of energy retrofit measures (ERMs) for an archetype of aged multi-storey residential buildings. Design/methodology/approach The methodology consists of three parts, namely, a desktop study including the selection of a case-study building and identification of ERM options for the building; development of a computer model to simulate the building’s energy use in the baseline scenario and different scenarios of ERMs; and evaluation of the ERMs based on energy-saving rate. Findings Among the 13 ERMs tested, lighting-related ERMs were found to be optimal measures while window fin is the least suitable option in terms of energy saving. Based on the research findings, a two-level retrofitting framework was developed for aged multi-storey buildings. Research limitations/implications Future studies may take a similar approach of this study to develop retrofitting frameworks for other types of buildings, and further research paper can be extended to study retrofitting for buildings in a district or a region. Practical implications The findings of this study can serve as a reference for building owners to select effective ERMs for aged multi-storey buildings, which invariably exist in developed cities. Originality/value This study presents a pioneering work where an energy model and a building archetype were used to analyze the energy savings of a variety of ERMs that are applicable to aged multi-storey buildings.

Understanding intentions to reduce energy consumption at the workplace by the employees: case of a developing country

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Amna Akhound ◽  
Aseem Majeed Rizvi ◽  
Waqar Ahmed ◽  
Muhammad Nadeem Khan
Keyword(s):  
Energy Saving ◽  
Structural Equation ◽  
Energy Use ◽  
Energy Savings ◽  
Theoretical Research ◽  
Equation Modeling ◽  
Survey Method ◽  
Content Type ◽  
Saving Behavior ◽  
Save Energy

PurposeEnergy-saving behavior of individuals is essential to minimize energy use and reduce the emission of toxic gases. This study's actual focus is to find out the determinants of the energy-saving behavior of individuals in the workplace.Design/methodology/approachAs a theoretical research model, the extended theory of planned behavior (TPB) has been used to analyze the determinants of energy-saving intentions. A survey method is used to collect 289 valid data, and structural equation modeling (SEM) is used to analyze the data.FindingsThe final result shows that the variables attitude at home, subjective norm (SN) and descriptive norms positively impact intention to save energy at the workplace. In contrast, the construct attitude and perceived behavior control is insignificant in this research. On the other hand, the personal moral norm (PMN) is a powerful predictor of individual energy-saving intentions at the workplace.Originality/valueThis research provides insights that will help the organizations understand the behavior of individuals at the workplace for energy-saving intentions to formulate such policies that will enhance individuals' practice for energy savings.

scholarly journals Demand Control Strategies of a PCM Enhanced Ventilation System for Residential Buildings

2020 ◽  
Vol 10 (12) ◽  
pp. 4336
Author(s):  
Yue Hu ◽  
Per Kvols Heiselberg ◽  
Tine Steen Larsen
Keyword(s):  
New York ◽  
Energy Storage ◽  
Energy Saving ◽  
Energy Savings ◽  
Control Strategies ◽  
Residential Buildings ◽  
Ventilation System ◽  
Airflow Rate ◽  
Energy Saving Potential ◽  
Demand Control

A ventilated window system enhanced by phase change material (PCM) has been developed, and its energy-saving potential examined in previous works. In this paper, the ventilation control strategies are further developed, to improve the energy-saving potential of the PCM energy storage. The influence of ventilation airflow rate on the energy-saving potential of the PCM storage is firstly studied based on an EnergyPlus model of a sustainable low energy house located in New York. It shows that in summer, the optimized ventilation airflow rate is 300 m3/h. The energy-saving of utilizing a ventilated window with PCM energy storage is 10.1% compared to using a stand-alone ventilated window, and 12.0% compared to using a standard window. In winter, the optimized ventilation airflow rate is 102 m3/h. The energy-saving of utilizing a ventilated window with PCM energy storage is 26.6% compared to using a stand-alone ventilated window, and 32.8% compared to using a standard window. Based on the optimized ventilation airflow rate, a demand control ventilation strategy, which personalizes the air supply and heat pump setting based on the demand of each room, is proposed and its energy-saving potential examined. The results show that the energy savings of using demand control compared to a constant ventilation airflow rate in the house is 14.7% in summer and 30.4% in winter.

Sensitivity of automatic control of emergency manoeuvre to parametric uncertainty of the airplane model

2019 ◽  
Vol 91 (3) ◽  
pp. 407-419
Author(s):  
Jerzy Graffstein ◽  
Piotr Maslowski
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Flight Control ◽  
Parametric Uncertainty ◽  
Second Phase ◽  
Flight Control System ◽  
Content Type ◽  
Control Quality ◽  
Wide Range ◽  
The Impact

Purpose The main purpose of this work was elaboration and verification of a method of assessing the sensitivity of automatic control laws to parametric uncertainty of an airplane’s mathematical model. The linear quadratic regulator (LQR) methodology was used as an example design procedure for the automatic control of an emergency manoeuvre. Such a manoeuvre is assumed to be pre-designed for the selected airplane. Design/methodology/approach The presented method of investigating the control systems’ sensitivity comprises two main phases. The first one consists in computation of the largest variations of gain factors, defined as differences between their nominal values (defined for the assumed model) and the values obtained for the assumed range of parametric uncertainty. The second phase focuses on investigating the impact of the variations of these factors on the behaviour of automatic control in the manoeuvre considered. Findings The results obtained allow for a robustness assessment of automatic control based on an LQR design. Similar procedures can be used to assess in automatic control arrived at through varying design methods (including methods other than LQR) used to control various manoeuvres in a wide range of flight conditions. Practical implications It is expected that the presented methodology will contribute to improvement of automatic flight control quality. Moreover, such methods should reduce the costs of the mathematical nonlinear model of an airplane through determining the necessary accuracy of the model identification process, needed for assuring the assumed control quality. Originality/value The presented method allows for the investigation of the impact of the parametric uncertainty of the airplane’s model on the variations of the gain-factors of an automatic flight control system. This also allows for the observation of the effects of such variations on the course of the selected manoeuvre or phase of flight. This might be a useful tool for the design of crucial elements of an automatic flight control system.

Energy-Saving Evaluation of SOFC Cogeneration Systems With Solar Cell and Battery

2014 ◽  
Vol 11 (6) ◽  
Author(s):  
Akira Yoshida ◽  
Koichi Ito ◽  
Yoshiharu Amano
Keyword(s):  
Solar Cell ◽  
Energy Saving ◽  
Energy Supply ◽  
Energy Savings ◽  
Optimization Theory ◽  
Maximum Energy ◽  
Planning Problem ◽  
Energy Supply System ◽  
Energy Demands ◽  
Cogeneration System

The purpose of this study is to evaluate the maximum energy-saving potential of residential energy supply systems consisting of a solid oxide fuel cell (SOFC) cogeneration system (CGS) combined with a solar cell (SC) and a battery (BT), compared with a reference system (RS). This study applies an optimization theory into an operational planning problem to measure actual energy demands over the course of 1 year. Eight different types of energy supply system were compared with each other by changing the components of the SOFC-CGS, SC, BT, and RS. Meaningful numerical results are obtained, indicating the maximum potential energy savings.

Development of Advanced Train Control System in Japan and its Energy Saving Effect

2012 ◽  
Vol 512-515 ◽  
pp. 1326-1332
Author(s):  
Hideo Nakamura ◽  
Jia Sun ◽  
Sei Takahashi ◽  
Masanori Yamamoto
Keyword(s):  
Control System ◽  
Energy Saving ◽  
Energy Savings ◽  
Low Cost ◽  
High Energy ◽  
Energy Reduction ◽  
Train Control ◽  
Block System ◽  
Train Control System ◽  
Saving Effect

Railways are an energy-efficient mode of transportation. Even so, efforts are being made to attain even further energy savings. The latest train-car model of the Shinkansen bullet train, while achieving enriched functionality and improved performance, has attained a 49% energy reduction compared with the 0-series Shinkansen train-cars that debuted at the start of Shinkansen's operation. Also, in the underlying train control system, technologies that will lead to energy reduction have been developed. In order to achieve further energy savings and higher-performance train control, we are developing a new train control system known as Automatic Train Protection and Block System (sometimes referred to ATP-Block system here). This new control system produces a high energy-saving effect compared with conventional signal systems based on ground equipment. We believe that realization of low-cost, highly functional energy-saving Railways will bring back users of automobiles and airlines to Railways, contributing to global energy saving and helping to prevent environmental destruction.

scholarly journals Competing priorities: lessons in engaging students to achieve energy savings in universities

2018 ◽  
Vol 19 (7) ◽  
pp. 1220-1238 ◽  
Author(s):  
Richard Bull ◽  
Joanna Romanowicz ◽  
Neil Jennings ◽  
Marina Laskari ◽  
Graeme Stuart ◽  
...  
Keyword(s):  
Energy Saving ◽  
Real Time ◽  
Behaviour Change ◽  
Energy Savings ◽  
Small Scale ◽  
Short Term ◽  
National Union ◽  
Content Type ◽  
Energy Dashboard ◽  
The Impact

PurposeThis paper aims to present findings from an EU-funded international student-led energy saving competition (SAVES) on a scale previously unseen. There are multiple accounts of short-term projects and energy saving competitions encouraging pro-environmental behaviour change amongst students in university dormitories, but the purpose of this research is to provide evidence of consistent and sustained energy savings from student-led energy savings competitions, underpinned by practical action.Design/methodology/approachA mixed-methods approach (pre- and post-intervention surveys, focus groups and analysis of energy meter data) was used to determine the level of energy savings and quantifiable behaviour change delivered by students across participating university dormitories.FindingsThis research has provided further insight into the potential for savings and behaviour change in university dormitories through relatively simple actions. Whilst other interventions have shown greater savings, this project provided consistent savings over two years of 7 per cent across a large number of university dormitories in five countries through simple behaviour changes.Research limitations/implicationsAn energy dashboard displaying near a real-time leaderboard was added to the engagement in the second year of the project. Whilst students were optimistic about the role that energy dashboards could play, the evidence is not here to quantify the impact of dashboards. Further research is required to understand the potential of dashboards to contribute to behavioural change savings and in constructing competitions between people and dormitories that are known to each other.Social implicationsSAVES provided engagement with students, enabling, empowering and motivating them to save energy – focusing specifically on the last stage of the “Awareness, Interest, Desire, Action” framework. Automated meter reading data was used in the majority of participating dormitories to run near real-time energy challenges through an energy dashboard that informed students how much energy they saved compared to a target, and encouraged peer-to-peer learning and international cooperation through a virtual twinning scheme.Originality/valueFindings from energy saving competitions in universities are typically from small-scale and short-term interventions. SAVES was an energy-saving competition in university dormitories facilitated by the UK National Union of Students in five countries reaching over 50,000 students over two academic years (incorporating dormitories at 17 universities). As such it provides clear and important evidence of the real-world long-term potential efficiency savings of such interventions.

Control of bearingless electric machines dedicated for aviation

2020 ◽  
Vol 92 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Mariusz Żokowski ◽  
Krzysztof Falkowski ◽  
Paulina Kurnyta-Mazurek ◽  
Maciej Henzel
Keyword(s):  
Control System ◽  
Electric Motor ◽  
Position Control ◽  
Experimental Studies ◽  
Electric Machines ◽  
Magnetic Suspension ◽  
Content Type ◽  
Actuation System ◽  
Bearingless Motor ◽  
Rotary Speed

Purpose The paper presents the results of work on control systems of bearingless electric motors. Authors proposed the applications of bearingless electric machines for aircraft actuation system. Suggested solution characterizes novel concept of on-board equipment design such as More Electric Aircraft. Magnetic suspension technology allows elimination of friction force and the negative performance features of classic bearing system. However, to achieve all these purposes appropriately, dedicated control system must be also applied. Design/methodology/approach The development of a control system of bearingless electric machine is presented in detail. Mathematical model and construction of induction bearingless motor are widely discussed. Then, proportional–integral-derivative controller algorithm designing for BEM control system was presented using the well pole placement method. Simulation model of BEM control system with use of Matlab-Simulink software was shown. Finally, experimental studies on laboratory stand were introduced. The paper presents design methodology of conventional and advanced control system of bearingless motor. Findings The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap. Practical implications The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap. Originality/value The idea of active magnetic suspension system will be implemented for aviation on technology readiness level V. The paper presents unique laboratory stand with bearingless electric motor and experimental studies. The stable time responses of designed control system were presented and discussed. In addition, preliminary considerations of advanced control system with robust controller were introduced as well.

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