http://www.ifac-papersonline.net/ en Copyright 04:31 PM Saturday 18, 2013 IFAC-PapersOnline http://www.ifacpapersonline.com 04:31 PM Saturday 18, 2013 04:31 PM Saturday 18, 2013 ET webmaster@ifac-papersonline.net webmaster@ifac-papersonline.net http://www.ifac-papersonline.net/Detailed/42968.html 04:00 PM Wednesday 31, 1969 http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42969.html 04:00 PM Wednesday 31, 1969 http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42970.html 04:00 PM Wednesday 31, 1969 Large off-shore wind farms based on synchronous generators can be connected to the mainland grid using modern wind turbines allow for tight control of terminal voltage. Therefore, an integrated design of wind turbine and HVDC link control can lead to a substantial simplification of the off-shore rectifier. This paper introduces an integrated control algorithm for line commutated thyristor (LCT) based HVDC transmission line whereby the off-shore rectifier tap changer is eliminated and a cheaper and more efficient uncontrolled rectifier is used instead of a LCT-based rectifier. The presented control strategy allows for off-shore ac-grid voltage and frequency control and shows good performance during steady state and transient operation, including on-shore fault ride-through operation. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42971.html 04:00 PM Wednesday 31, 1969 The actual wind turbines are provided with adjustable speed generators, like the double feed induction generator, that are capable to work in variable speed operations. One of the main advantage of adjustable speed generators is that they improve the system efficiency compared to fixed speed generators because turbine speed is adjusted as a function of wind speed to maximize output power. However this systems requires a suitable speed controller in order to track the optimal wind turbine speed reference. In this work, it is proposed a sliding mode control for variable speed wind turbines. The robustness analysis of the proposed controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory and simulated results show that the proposed controller provides a good performance. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42972.html 04:00 PM Wednesday 31, 1969 This paper concentrates on the possible directions of examination in the frame of one of the projects fulfilled under FP7 program umbrella. In 2009 the project "Intelligent Coordination of Operation and Emergency Control of European Union and Russian Power Grids" has been started to develop the prototype of the large power system SCADA/EMS. The project could become the basis for development of the main principles for the control system of possible UCTE-IPS/UPS interconnection that could be occurring in the near future. The paper ascertains the potential of attracting both back-to-back converter stations and wind power plants to increase the efficiency of functioning of the power system emergency control structure. The possible ways of improving of UCTE-IPS/UPS interconnection with the use of the recently obtained results of the UCTE-IPS/UPS feasibility study are discussed. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42973.html 04:00 PM Wednesday 31, 1969 Presently, available commuter electric vehicles have a battery capacity roughly equivalent to the average Australian householder's daily electricity consumption (25kWh). Naively, converting the entire fleet of commuter vehicles to electric vehicles appears therefore only feasible if the installed electrical power generation capacity doubles in size. The driver for this conversion from petrol/gas internal combustion engines to electric motors for commute vehicles stems from the significant greenhouse gas reduction that can be realized. Nevertheless doubling the electrical grid's capacity comes with too heavy a price tag. The only realistic way forward is to exploit demand management, based on the observation that peak generation is only used for a very small fraction of time, and that most car batteries can be charged off-peak. Using a smart grid enabled load management system it is possible to alleviate the need for substantial additional generation capacity. Moreover, the available electric vehicle battery storage can be used to advantage to increase the power generation contribution from wind and other alternative and hopefully more sustainable sources. This strengthens the case for the conversion. This paper considers a potential demand management approach that enables a high uptake of electric vehicles in an Australian urban context. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42974.html 04:00 PM Wednesday 31, 1969 This paper presents a conceptual framework to enable a successful integration of Electric Vehicles (EV) into isolated power systems. The developed framework includes the management and control actions that might be implemented over EV in order to improve the system's resilience. Several dynamic stability simulations were performed, using a small isolated grid as a test system, in order to demonstrate the possible contributions EV may provide to fast power/frequency control, either as a highly flexible and controllable load and/or as an energy storage device. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42975.html 04:00 PM Wednesday 31, 1969 For a vehicle hybrid electric (VHE) system powered by the batteries and supercapacitors (SC), a real-time optimal power management (OPM) algorithm is proposed based on the look-ahead route information in consideration of the complex traffic environment. At first, a configuration and modeling of the VHE system is addressed. Then, enlighten by the model predictive control (MPC), multiple route information including the traffic and the road terrain over a look-ahead horizon is utilized to predict the future states, and a cost function to minimize total energy loss of the VHE system is given. On above preliminaries, the dynamic programming (DP) algorithm is applied recursively over the look-ahead horizon to update the optimal power distribution between the battery and SC during the total route. Finally, the simulation results confirm that the computational time of OPM has been reduced significantly although a part of energy efficiency is sacrificed. Moreover, the behavior of OPM is similar to that of a skilful driver and thus appropriate be applied to the practical traffic environment. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42976.html 04:00 PM Wednesday 31, 1969 Most of the time, people usually do their daily activities inside a building. Thus, it is necessary to reach comfort conditions for the people. This paper presents a hierarchical control system which allows to obtain a high comfort level, optimizing the use of HVAC (Heating, Ventilation and Air Conditioning) systems and actuators while minimizing energy consumption. Specifically, in this paper an analysis about the relation between comfort (thermal comfort, visual comfort and indoor-air quality) and different degrees of freedom to control inside a research center is done. The main objective is to obtain a cost function which allows to determine optimal conditions of humidity, temperature, illuminance and CO2 concentration minimizing energy consumption. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42977.html 04:00 PM Wednesday 31, 1969 This paper presents the development of a supervision and control system architecture to assist the residential user saving resources and detecting failures. Similar to what happened in the automobile industry, the increasing number of sensors and actuator existing on a building requires a robust, fexible and reliable system. The proposed system uses a microcontroller network to acquire data from sensors and control actuators using different protocols (CAN, I2C and Modbus). The system information and control is provided through a local and remote user interface application, using a computer connected to the network, a database and dedicated software applications. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42978.html 04:00 PM Wednesday 31, 1969 When intending to renovate an existing building, with energy efficiency and greenhouse gas emissions in mind, a building owner is always questioning himself if the available investment resources are being directed to an effective return and if there are ways to improve this return? This paper presents the innovative approach from EnPROVE project that responds the previous question in a positive way. The approach is based on predicting the energy consumption of a specific building, with different scenarios implementing energy-efficient technologies and control solutions, based on actual measured performance and usage data of the building itself. The key hypothesis of EnPROVE is that it is possible, from adequate gathering and assessing data on how a structure performs and is being used by its occupants from an energy viewpoint, to build highly accurate and specific energy consumption models relevant for prediction of alternative scenarios. The EnPROVE software tools assess the energy-efficiency impact of alternative technologies for which available investment resources can be directed and, thus, support the decision maker finding the optimized set of energy-efficient solutions to be implemented. These results are tailored to the actual building itself, through automated measurements of building usage and energy consumption. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42979.html 04:00 PM Wednesday 31, 1969 In order to improve the building thermal efficiency, increase the human thermal comfort level and to reduce the building energy consumption, in this work, the human thermo-physiological sensation control, based in the adaptive comfort philosophy, is applied. In this control methodology the occupants, during a lesson activity, can choose among the clothing level, the activity level and the natural ventilation system. The PMV and PPD indexes are used in the numerical simulation. This work is made in a classroom school building, in the Algarve region, with Mediterranean characteristics, in Spring conditions, based in air temperature and relative humidity measurements. The comparison of the human thermal comfort level without and with control strategies is made. The obtained results are used to define an applicable activity, clothing and ventilation strategy, during the day. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42980.html 04:00 PM Wednesday 31, 1969 Key design parameters (in terms of their influences on building energy consumption) through sensitivity analysis for fully air-conditioned office buildings in five cities (Harbin, Beijing, Shanghai, Kunming and Hong Kong) representing the five major climate zones (severe cold, cold, hot summer and cold winter, mild, and hot summer and warm winter) across China have been identified. These include: i) building envelope - window shading coefficient, window U-value and window-to-wall ratio; ii) internal load - equipment, lighting and occupancy; iii) HVAC system - outdoor fresh air, summer and winter thermostat set points, fan efficiency and fan static pressure; and iv) HVAC plant - chiller COP and boiler efficiency. The influence coefficient (IC, a ratio of the percentage change in computed output (building energy use) to the percentage change in input design parameter was used to indicate likely energy savings. For instance, Hong Kong has a lighting load IC of 0.359, suggesting that a 20% reduction (e.g. from 18 to 14.4 W/m2) in lighting load could result in more than 7% reduction in the total building energy use. Furthermore, Hong Kong also has a summer thermostat set point IC of -1.131, suggesting that a 5% increase in the indoor temperature during the summer (e.g. from 26 to 27.3°C) could result in about 6% energy savings. Given the growing awareness of adaptive thermal comfort, this could be a no-cost energy-efficient measure with great energy saving potential. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42981.html 04:00 PM Wednesday 31, 1969 A Markov modeling technique is proposed, aiming at energy efficient optimal control of the gas turbine based power plant. A new characteristic of the dynamic Markov models is developed in the form of the final phase trajectory representing the determined part of the system stochastic dynamics. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42982.html 04:00 PM Wednesday 31, 1969 This paper describes the modeling and control of a thermoacoustic unstable burner. The thermoacoustic system is modeled using a 1D-acoustic network coupled with a flame transfer function derived from Computational Fluid Dynamics (CFD). The resulting unstable system provides a realistic test bench for controller evaluation and is controlled using a Model Predictive Controller (MPC) with a sampling time of 0.001s. As QP solver the homotopy approach of qpOASES is used. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42983.html 04:00 PM Wednesday 31, 1969 Data from a bubbling fluidized bed boiler was tentatively analyzed in order to find dependence among process variables. The data used was collected during normal operation of the power plant. Data was analyzed by using correlation analysis and the self-organizing map (SOM), which is a useful tool for visualization. SOM component planes and the U-matrix were utilized for visualization. Both correlation and SOM analysis showed similar results. For example, pressure differences across different parts of the flue gas duct had a practically linear correlation, flue gas temperature in stack requires further analysis because of surprisingly low correlation with other measurement points and flue gas SOx and NOx contents did not correlate. The visual presentation of SOM supported the results obtained from the correlation analysis. With the used methods, dependence among variables can be evaluated in a computationally inexpensive way and recognized both quantitatively and qualitatively. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42984.html 04:00 PM Wednesday 31, 1969 In this paper we consider an oxy-coal thermoelectric plant fed by a coal-water mixture (slurry) and oxygen (instead of air). The use of pure oxygen makes it easier to capture CO2. A distinctive feature of such a plant is that the combustion and flue gases system operates at high pressure (about 10 bar). We develope a model based on first principles equations in order to study the startup procedures. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42985.html 04:00 PM Wednesday 31, 1969 This paper presents an approach to pressure/under-pressure and load distribution control of fresh air supply and exhaust fans at thermal power plants, where dual actuators are used. The proposed concept, relative to standard solutions, offers better performance, simplified tuning and start-up, and safer operation in terms of over-current protection. Pressure/under-pressure and load distribution of the two fans by means of flap position relies on two PI pressure controllers, two PI current controllers (when over-current protection is active), and one PD controller for load distribution control between the two drives. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42986.html 04:00 PM Wednesday 31, 1969 In this work a numerical model, which simulates the buildings thermal response and evaluates the indoor environment comfort, in transient conditions, is used in the application of Heating, Ventilating and Air Conditioning (HVAC) systems control, based in the Predicted Mean Vote (PMV) index, in the energy and thermal comfort performance in a kindergarten school building, in the South of Portugal, in Winter conditions. In the control the PMV index, based in the mean air temperature, the mean air velocity, the mean air relative humidity, the mean radiant temperature, the clothing level and the activity level, are used. In the numerical simulation of the kindergarten, the 25 compartments, the 498 building main bodies and the 42 windows glasses, as well as two schools and three residential surrounding main buildings, are considered. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42987.html 04:00 PM Wednesday 31, 1969 A computer simulation is developed to study the energy efficiency of a heat pump with a controlled variable speed compressor to heat bath water in a residential building. The usage of electric energy to heat water in Brazil will be discussed to give the context of the proposed set. Scroll compressor is chosen as the variable speed compressor, a heat pump model is used and also water distribution models that consider the local heat losses. A PID controller is used and different techniques of references are considered to determine the reservoir water temperature. Results are discussed and compared to traditional Joule effect water heating. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42988.html 04:00 PM Wednesday 31, 1969 This paper develops an operational control platform for intelligent buildings using a SCADA system (Supervisory Control And Data Acquisition). This SCADA system integrates different types of information coming from the several technologies present in modern buildings (control of ventilation, temperature, illumination, etc.). The developed control strategy implements an hierarchical cascade controller where inner loops are performed by local PLCs (Programmable Logic Controller), and the outer loop is managed by the centralized SCADA system, which interacts with the entire local PLC network. In this paper a Predictive Controller is implemented at the centralized SCADA platform. Tests applied to the control of temperature and luminosity in huge-area rooms are presented. The developed Predictive Controller tries to optimize the satisfaction of user explicit preferences coming from several distributed user-interfaces, subjected to the constraints of energy waste minimization. In order to run the Predictive Controller at the SCADA platform a communication channel was developed to allow communication between the SCADA application and the MATLAB application where the Predictive Controller runs. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42989.html 04:00 PM Wednesday 31, 1969 One of the options to increase the energy efficiency of current electricity network is the use of a Virtual Power Plant. By using multiple small (micro)generators distributed over the country, electricity can be produced more efficiently since these small generators are more efficient and located where the energy is needed. In this paper we focus on micro Combined Heat and Power generators. For such generators, the production capacity is determined and limited by the heat demand. To keep the global electricity network stable, information about the production capacity of the heat-driven generators is required in advance. In this paper we present methods to perform heat demand prediction of individual households based on neural network techniques. Using different input sets and a so called sliding window, the quality of the predictions can be improved signicantly. Simulations show that these improvements have a positive impact on controlling the distributed microgenerators. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42990.html 04:00 PM Wednesday 31, 1969 The use of artificial neural networks in various applications related with energy management in buildings has been increasing significantly over the recent years. One of these applications is predictive HVAC control, which aims to maintain thermal comfort while simultaneously minimizing the energy spent, within a specified prediction horizon. Thermal comfort depends on several variables; among them inside temperature and relative humidity are key factors. In this paper the design of predictive neural network models for these two climate variables is discussed. The design approach uses a Multi-Objective Genetic Algorithms (MOGA) to determine the structure of the network, together with an efficient derivative-based estimation algorithm. Simulations with real weather and climate data show that excellent predictive models can be obtained with this methodology. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42991.html 04:00 PM Wednesday 31, 1969 Fluid leakage is a major economic and environmental challenge in several areas, this issue explains the growing interest by the scientific and industrial communities for the development of a reliable algorithms of leak diagnosis. This paper deals with reliability analysis of a leak detection system developed by OSYRIS R&D company (high-tech company specialized in the field of the laser). The developed algorithm is based on signal processing theory, it uses the properties of the cross-correlation function in order to distinguish the fluid leak from a various disturbances. Experimental results obtained in real time show the advantages and limits of the proposed approach. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif http://www.ifac-papersonline.net/Detailed/42992.html 04:00 PM Wednesday 31, 1969 This paper studies the improvement obtained by taking driving cycle predictions into account in the power management control of a Fuel Cell hybrid vehicle (FCHV). The objective is to estimate a driving cycle from Global Position System (GPS) information and then to optimize a reduced problem in order to calculate a optimal battery state of charge and a motor power prediction. The control architecture is comprised of a Hybrid MPC controller and a reference governor which consists of a estimator and a optimizer. The results shown herein are promising reducing the hydrogen consumption up to 9.5%. http://www.ifac-papersonline.net/static/luna/images/ifac/icon-download.gif