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149 A multivariable robust controller design for a single machine infinite-bus system
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Abstracts
139 Indirect Estimation of Thermal Networks P. Hiindel, pp 669.672 A procedure for estimating the parameters of lumped parameter models (thermal networks) describing thermal properties in buildings has been derived. The statistically efficient method is .l.~fonned in two steps, where the first step uses standard system identification tools for black-box modeling. The estimates from the first step are used as input data to the second step, where the parameters c~ a given thermal network are estimated. The method ts applied to measurements from a prototype PASSYS test cell at the J.R.C. in Ispra, Italy, and the estimauon results are compared with resultspreviouslypresented in the literature. 140 Knowledge-Based Monitoring of Conl.Fired Power plants G.K. Lausterer, pp 673.680 The increasing complexity of coal-fired power plants, especially that due to added environmental protection equipment like flue gas desulpherization (FGD) plants, places high demands on controlroom operators. These may be alleviated by using a knowledgebased system for process monitoring and operator support. KNOBOS (J~I3LQwledge-Based Qperator .~.ystem)provides for the acquisition and monitoring of process status, prediction of incipient malfunctions, diagnosttc and prognostic functions, instruction on preventive or remedial actions, consulting and optimizing functions. The G2 real-time expert-system shell was used to implement KNOBOS. First experience with knowledge acquisition for an FGD plant is reported (pilot project). 141 Dynamic Model for a Fluidized Bed Coal Combustor (Including Bed Fuel Inventory) E. Ikonen, U. Kortela, pp 681-684 Bed fuel inventory is one of the key variables in the fluidized bed combustion proces when describing the dynamic behaviour of combustors bum'msg fuels like coal or graphite. Many of the essential features of fluidized bed combustor responses can be simulated with the dynamic model presented here. The model consists of differential equations describing the dynamic behaviour of the furnace and steady-state calculations for the burning of char particles. The simulations show good agreement when compared to process measurements from a commercial-sized coal combustor. 142 Control System Design for the Plasma Equilibrium of a Tokamak Experiment W. Woyke, G. Schmldt, pp 685-688 This paper presents a model-based approach to plasma position and shape control in a large-scale tokamak experiment. The dynamically unstable plasma in controlled by a complex configuration of magnetic coil systems. Starting from the most comprehensive magnetohydrodynamic (MHD) model of the lasma, a series of reduced-order models is derived for purposes of back control design. It is shown that the multivariable plasma cuntrol problem can be decomposed into four major groups of control tasks. Experiments performed recently with the real machine, ASDEX Upgrade, confirmed predictions of the preceding design and simulation studies. 143 Modelling Wave Disturbances on a Swath Vessel Using Directional Energy Sea Spectra Providing Spatial Wave Profiles In Time N.L. Chinn, G.N. Roberts, pp 689.692 A method to approximately model the sea, for short- and longcrested waves, ts described in this paper. Depth effects are included since this study grew out of a previous study (1993), looking into the application of this technique in the shallow running of torpedoes. Random time histories with given stochastic >erties, for simulating the motion of adjacent water particles, provided. The method used produces, at each time step, an instantaneous wave profile, with depth attenuation and various perspectives taken into account. In this case, for wave profiles along each hull of a SWATH, the influence of the sea's motion on individual hull sections can be determined. 144 Energy Issues for Industrial Development Chun H. Cho, pp 693-696 Many energy issues are critical to industrial development: resources management and planning, infrastructure to establish
energy policies and codes, energy allocation and pricing, technological issues focusing on the energy efficiency of eqm.'pment' production facilities, and protection of the environment. Energy issues also encompass conservation of natural resources, manpower training, use of alternative fuels, and optimum allocation and utilization of b~-preduct fuels. For a grass-reots industrial plant or the renovauon of an existing plant, the trend is to include a real-time computer system for monitoring and control/optimization of energy systems as an integnd part of a plant-wide manufacturing strategy to optimize and reduce the production costs. 145 Adaptive Control for Steam Temperature of Thermal Power Plant S. Matsumura, K. Ogata, S. FuJll, H. Shioya, H. Nakamura, pp 697-702 A discrete-time adaptive control system was applied to the steam temperature control of a boiler for electric power generation. In the system the adaptive controllers are applied in parallel with conventional PID controllersfor superheated and reheated steam temperatures. The plant dynamics were described by polynomials whose parameters are adaptively estimated from the data of the plant under routine operauon. The adaptive control signals are synthesized on the basis of the estimated parameters so as to achieve the specified control objective. The system was applied to a 375MW plant and found to realize far better control performance than the conventional PID control system. 146 A Fuzzy Logic Controller Design for Nuclear Power Plant P. Ramaswamy, R.M. Edwards, K.Y. Lee, pp 703-706 A fuzzy logic controUer design for a wide-range reactor temperature control is presented. Typically, fuzzy logic controllers are designed on the basis of an expert's knowledge of the process. However this approach has its limitations, in that the controller is hard to optimize. In this paper a method to automate the optimizing process using a simplified Kalman filter approach is presented. The resulting controller displayed good stability and performance robustness characteristics for a wide range of operation.
147 Decentralized Adaptive Control of a Nuclear Reactor J.S.B. Read, M. Jamshldi, C. Abdallah, pp 707-710 The adaptive decentralized control of large scale systems (LSS) using local state feedback is investigated. The results are then applied to a liquid metal cooled nuclear reactor.
148 Application of Adaptive Control Concept in a 750 MW Coal Fired Power Plant I. Kocaarslan, pp 711-718 This paper presents a real-time application of adaptive control in a typical industrial plant whose performance is severely affected by disturbances (particularly changes in the operating point). A short description of a large coal-fired power plant is given, and a reduced mathematical model is developed and briefly discussed. The conventional control of this power plant is investigated and described. The design of the adaptive model-reference controller is presented and realized. The results of a three-month pilot installation of a decentralized adaptive control algorithm for realtime electrical power and enthalpy control of a 750-MW power plant are compared with those of the conventional PID control.
149 A Multivarlable Robust Controller Design for a Single Machine Infinite-Bus System Y.A. Smaill, A.T. Alouani, pp 719-722 This paper investigates the application of Hoo optimal control theory to the design of a supplementary excitation and governor control system to improve the stability and performance robusmess of an electric power system. This study is based on a singlemachine infinite-bus system. The effectiveness of the proposed controller was investigated using simulation of the nonlinear model. The simulation results show that the controlled system is robust in the face of different types of disturbances, such as changes in voltage or power reference level and three-phase short circuits occurring at the infinite-bus terminal.
Abstracts
139 Indirect Estimation of Thermal Networks P. Hiindel, pp 669.672 A procedure for estimating the parameters of lumped parameter models (thermal networks) describing thermal properties in buildings has been derived. The statistically efficient method is .l.~fonned in two steps, where the first step uses standard system identification tools for black-box modeling. The estimates from the first step are used as input data to the second step, where the parameters c~ a given thermal network are estimated. The method ts applied to measurements from a prototype PASSYS test cell at the J.R.C. in Ispra, Italy, and the estimauon results are compared with resultspreviouslypresented in the literature. 140 Knowledge-Based Monitoring of Conl.Fired Power plants G.K. Lausterer, pp 673.680 The increasing complexity of coal-fired power plants, especially that due to added environmental protection equipment like flue gas desulpherization (FGD) plants, places high demands on controlroom operators. These may be alleviated by using a knowledgebased system for process monitoring and operator support. KNOBOS (J~I3LQwledge-Based Qperator .~.ystem)provides for the acquisition and monitoring of process status, prediction of incipient malfunctions, diagnosttc and prognostic functions, instruction on preventive or remedial actions, consulting and optimizing functions. The G2 real-time expert-system shell was used to implement KNOBOS. First experience with knowledge acquisition for an FGD plant is reported (pilot project). 141 Dynamic Model for a Fluidized Bed Coal Combustor (Including Bed Fuel Inventory) E. Ikonen, U. Kortela, pp 681-684 Bed fuel inventory is one of the key variables in the fluidized bed combustion proces when describing the dynamic behaviour of combustors bum'msg fuels like coal or graphite. Many of the essential features of fluidized bed combustor responses can be simulated with the dynamic model presented here. The model consists of differential equations describing the dynamic behaviour of the furnace and steady-state calculations for the burning of char particles. The simulations show good agreement when compared to process measurements from a commercial-sized coal combustor. 142 Control System Design for the Plasma Equilibrium of a Tokamak Experiment W. Woyke, G. Schmldt, pp 685-688 This paper presents a model-based approach to plasma position and shape control in a large-scale tokamak experiment. The dynamically unstable plasma in controlled by a complex configuration of magnetic coil systems. Starting from the most comprehensive magnetohydrodynamic (MHD) model of the lasma, a series of reduced-order models is derived for purposes of back control design. It is shown that the multivariable plasma cuntrol problem can be decomposed into four major groups of control tasks. Experiments performed recently with the real machine, ASDEX Upgrade, confirmed predictions of the preceding design and simulation studies. 143 Modelling Wave Disturbances on a Swath Vessel Using Directional Energy Sea Spectra Providing Spatial Wave Profiles In Time N.L. Chinn, G.N. Roberts, pp 689.692 A method to approximately model the sea, for short- and longcrested waves, ts described in this paper. Depth effects are included since this study grew out of a previous study (1993), looking into the application of this technique in the shallow running of torpedoes. Random time histories with given stochastic >erties, for simulating the motion of adjacent water particles, provided. The method used produces, at each time step, an instantaneous wave profile, with depth attenuation and various perspectives taken into account. In this case, for wave profiles along each hull of a SWATH, the influence of the sea's motion on individual hull sections can be determined. 144 Energy Issues for Industrial Development Chun H. Cho, pp 693-696 Many energy issues are critical to industrial development: resources management and planning, infrastructure to establish
energy policies and codes, energy allocation and pricing, technological issues focusing on the energy efficiency of eqm.'pment' production facilities, and protection of the environment. Energy issues also encompass conservation of natural resources, manpower training, use of alternative fuels, and optimum allocation and utilization of b~-preduct fuels. For a grass-reots industrial plant or the renovauon of an existing plant, the trend is to include a real-time computer system for monitoring and control/optimization of energy systems as an integnd part of a plant-wide manufacturing strategy to optimize and reduce the production costs. 145 Adaptive Control for Steam Temperature of Thermal Power Plant S. Matsumura, K. Ogata, S. FuJll, H. Shioya, H. Nakamura, pp 697-702 A discrete-time adaptive control system was applied to the steam temperature control of a boiler for electric power generation. In the system the adaptive controllers are applied in parallel with conventional PID controllersfor superheated and reheated steam temperatures. The plant dynamics were described by polynomials whose parameters are adaptively estimated from the data of the plant under routine operauon. The adaptive control signals are synthesized on the basis of the estimated parameters so as to achieve the specified control objective. The system was applied to a 375MW plant and found to realize far better control performance than the conventional PID control system. 146 A Fuzzy Logic Controller Design for Nuclear Power Plant P. Ramaswamy, R.M. Edwards, K.Y. Lee, pp 703-706 A fuzzy logic controUer design for a wide-range reactor temperature control is presented. Typically, fuzzy logic controllers are designed on the basis of an expert's knowledge of the process. However this approach has its limitations, in that the controller is hard to optimize. In this paper a method to automate the optimizing process using a simplified Kalman filter approach is presented. The resulting controller displayed good stability and performance robustness characteristics for a wide range of operation.
147 Decentralized Adaptive Control of a Nuclear Reactor J.S.B. Read, M. Jamshldi, C. Abdallah, pp 707-710 The adaptive decentralized control of large scale systems (LSS) using local state feedback is investigated. The results are then applied to a liquid metal cooled nuclear reactor.
148 Application of Adaptive Control Concept in a 750 MW Coal Fired Power Plant I. Kocaarslan, pp 711-718 This paper presents a real-time application of adaptive control in a typical industrial plant whose performance is severely affected by disturbances (particularly changes in the operating point). A short description of a large coal-fired power plant is given, and a reduced mathematical model is developed and briefly discussed. The conventional control of this power plant is investigated and described. The design of the adaptive model-reference controller is presented and realized. The results of a three-month pilot installation of a decentralized adaptive control algorithm for realtime electrical power and enthalpy control of a 750-MW power plant are compared with those of the conventional PID control.
149 A Multivarlable Robust Controller Design for a Single Machine Infinite-Bus System Y.A. Smaill, A.T. Alouani, pp 719-722 This paper investigates the application of Hoo optimal control theory to the design of a supplementary excitation and governor control system to improve the stability and performance robusmess of an electric power system. This study is based on a singlemachine infinite-bus system. The effectiveness of the proposed controller was investigated using simulation of the nonlinear model. The simulation results show that the controlled system is robust in the face of different types of disturbances, such as changes in voltage or power reference level and three-phase short circuits occurring at the infinite-bus terminal.