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167 Machine learning of diagnostic knowledge for a power distribution fault diagnostician using a genetic algorithm
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Abstracts
application of the tieline Power of the system to the decentralized control design, An illustrative example shows that the define Power is an important variable, essenual to multimachine power system control. This study also suggests the possibility of a unified design for decentralized systems of both voltage and power stabilization and load frequency control.
when the model used in the controller design is of lower order than the true system. 166 Global Robust Adaptive Control of a Power System: Primary Control on the Electrical Side
H. Jiang, J.F. Dorsey, Z. Qu, T. Habetler, pp 805-808 161 Intelligent Adaptive Control of a Multi-Machine Power System
B.W. Hogg, S. Jovanovic, B. Fox, E. Swidenbank, pp 779-782 The paper presents an intelligent adaptive turbine control scheme intended to imwove the overall control performance of a multimachine power system. Supplementary rule-based control is applied to the turbine governor, taking account of generator acceleration/deceleration as a measure o f the imbalance between mechanical and electrical Power. It is shown that this approach is capable of achieving more-effective control of frequency transients on multi-machine Power systems.
A robust adaptive control scheme is presented, using control from the electrical side, which stabilizes a nonlinear model of a power system to disturbances anywhere in the Power system. The control is local, in the sense that the control of each machine depends only on information available at the machine. Simulation result, are presented which show that the control is very effective against stabilities of current importance such as sustained oscillations following a major system disturbance. 167 Machine Learning of Diagnostic Knowledge for a Power
Distribution Fault Diagnostidan Using a Genetk Algorithm J. Ypsilantis, H. Yee, pp 809.812
162 On the Design of Robust Hoe Optimal Controllers for
Synchronous Machines V.H. Quintana, T. Ravichandran, pp 783-788 This paper presents a design of robust controllers for synchronous machines using the He,, optimization approach. Assuming the system's parameters and P o w e r loads (operating point) are constandy changing around some nominal value, the proposed design minimizes the sensitivity term in the low frequency and improves system robustness to additive uncertainties. These objectives are embodied in a weighted mixed-sensitivity problem. Two Hoo controllers are designed for a synchronousmachine/mf'mite-bus system, each using a different pair of outputs available for control. Simulation results show that these controllers guarantee effective oscillation control of the power angle against possible operating-point uncertainties. 163 Influence of the Frequency and Voltage Dependence of Load Part Systems on the Control Behaviour of Power Systems During Emergency Conditions E. Welfondor, B. Hall, R. Neifer, pp 789-796 For the investigation of the frequency and voltage dependence of the load. data-acquisition systems have been installed and operated for more than two years in eight load part systems in Germany and France. The data-acquisition systems and the evaluation procedure developed for thispurpose are described, as well as the identified load parameters. The great influence of the frequency and voltage dependence of the load on the control behaviour of isolated and interconnected power systems is shown, especially during emergency conditions. 164 Nuclear Reactor Control Using Diagonal Recurrent Neural Networks C.-C. Ku, K.Y. Lee, R.M. Edwards, pp 797-800 A new approach for wide-range optimal reactor temperature control using diagonal recurrent neuralnetworks (DRNN) with an adaptive learning rate scheme is presented. The drawback of the usual feedforward neural network (FNN) is that it is a static mapping and requires a large number of neurons. The usual fixed learning rate based on empirical trial-and-error schemes is slow and does not guarantee convergence. The DRNN is used for dynamic mapping and requires a much smaUer number of neurons and weights, and thus converges faster than an FNN. Rapid convergence of this DRNN-based control system is demonstrated by improved reactor temperature performance. 165 Trade-Off Between Energy Capture and Dynamic Loads in Variable Speed Wind Turbines T. Ekelund, B. Schmidtbauer, pp 801-804 This paper investigates the trade-off between the objectives of generating maximum power and minimizing the dynamic loads of a variable-speed wind turbine operated below rated wind speed. Linear quadratic optimal control methods are used to investigate this balance. Four models of different complexity are compared, and are established to have similar behaviour. The controllers have been simulated with a non-linear aerodynamic torque model, and the simulation confirms the predicted characteristics. It is also shown that the systems are robust to parameter changes, even
Machine learning can be used in the acquisition of knowledge for an operator assistant system. In applications such as fault diagnosis, the order of occurrence of event, may be impestant. In actual systems, noise is also present. Machine-learning algorithms for diagnostic knowledge should be capable of inducing knowledge reliably from noisy input, taking the sequence of events into account. This paper presents a method, based on genetic learning, which may be applied to the acquisition of a knowledge base for fault diagnosis. The algorithm is evaluated using a distribution system fault simulator.
168 A New Load Shedding Scheme for Limiting Underfrequency W.R. Lachs, D. Prasetijo, D Sutanto, pp 813-816 Under-frequency load shedding alleviates load-generation imbalance following a sudden loss of large amounts of generation. Loads are shed at pre-scheduied locations throughout the power system. It would be better if load shedding were to occur at locations close to the lost generation, thereby reducing the reactive power losses associated with transmitting larger amounts of power to the disturbed location. A new hierarchical load-shedding scheme is p .r.oposed, based on frequency, voltage and rate of frequency decline, which utilizes distributed intelligence to shed load according to the actual system state at each locality.
169 Control Options in Power System Operation by Use of Flexible AC Transmission System (FACTS) D. Sutanto, W.R. Lachs, pp 817-820 Devices known as FACTS (flexible AC transmission systems) specially designed to introduce more "flexibility" both in normal and emergency .operation of an electric Power system have been proposed in the hterature. The flexibility is related to the direct control (both local and centralised) of beth active and reactive power. The main aim is to increase the utilisation of existing facilities even to their thermal limits (without sacrificing reliability). This paper provides a review of the basic cxmcel~s and the possible FACTS options. It then proposes the use of battery energy storage plants for use in the FACTS system. The advantages and disadvantages are discussed.
170 CO2-Recoverlng Power Generation System in a CO 2Recycling Global Energy System Based on Solar Energy P.S. Pak, Y. Suzuki, Y. Tazaki, pp 821-824 This paper describes the concept of a CO2-recycling global energy system utilizing solar energy. The construction and characteristics of a CO2-recovering high-efficiency power-generation system are described in detail. In the power generation system, CO 2 gas is the working fluid of a closed-cycle gas-turbine power-generation system, and it is assumed that methanol is burnt in a combustor using oxygen. CO 2 gas included in the exhaust gas can be easily separated at the condenser oudet and mused m synthesize methanol. Gross thermal efficiency has been estimated at 54.6%. Net power generation efficiency has been estimated at 50.8% when considering the electric power required for liquefying recovered CO 2.
Abstracts
application of the tieline Power of the system to the decentralized control design, An illustrative example shows that the define Power is an important variable, essenual to multimachine power system control. This study also suggests the possibility of a unified design for decentralized systems of both voltage and power stabilization and load frequency control.
when the model used in the controller design is of lower order than the true system. 166 Global Robust Adaptive Control of a Power System: Primary Control on the Electrical Side
H. Jiang, J.F. Dorsey, Z. Qu, T. Habetler, pp 805-808 161 Intelligent Adaptive Control of a Multi-Machine Power System
B.W. Hogg, S. Jovanovic, B. Fox, E. Swidenbank, pp 779-782 The paper presents an intelligent adaptive turbine control scheme intended to imwove the overall control performance of a multimachine power system. Supplementary rule-based control is applied to the turbine governor, taking account of generator acceleration/deceleration as a measure o f the imbalance between mechanical and electrical Power. It is shown that this approach is capable of achieving more-effective control of frequency transients on multi-machine Power systems.
A robust adaptive control scheme is presented, using control from the electrical side, which stabilizes a nonlinear model of a power system to disturbances anywhere in the Power system. The control is local, in the sense that the control of each machine depends only on information available at the machine. Simulation result, are presented which show that the control is very effective against stabilities of current importance such as sustained oscillations following a major system disturbance. 167 Machine Learning of Diagnostic Knowledge for a Power
Distribution Fault Diagnostidan Using a Genetk Algorithm J. Ypsilantis, H. Yee, pp 809.812
162 On the Design of Robust Hoe Optimal Controllers for
Synchronous Machines V.H. Quintana, T. Ravichandran, pp 783-788 This paper presents a design of robust controllers for synchronous machines using the He,, optimization approach. Assuming the system's parameters and P o w e r loads (operating point) are constandy changing around some nominal value, the proposed design minimizes the sensitivity term in the low frequency and improves system robustness to additive uncertainties. These objectives are embodied in a weighted mixed-sensitivity problem. Two Hoo controllers are designed for a synchronousmachine/mf'mite-bus system, each using a different pair of outputs available for control. Simulation results show that these controllers guarantee effective oscillation control of the power angle against possible operating-point uncertainties. 163 Influence of the Frequency and Voltage Dependence of Load Part Systems on the Control Behaviour of Power Systems During Emergency Conditions E. Welfondor, B. Hall, R. Neifer, pp 789-796 For the investigation of the frequency and voltage dependence of the load. data-acquisition systems have been installed and operated for more than two years in eight load part systems in Germany and France. The data-acquisition systems and the evaluation procedure developed for thispurpose are described, as well as the identified load parameters. The great influence of the frequency and voltage dependence of the load on the control behaviour of isolated and interconnected power systems is shown, especially during emergency conditions. 164 Nuclear Reactor Control Using Diagonal Recurrent Neural Networks C.-C. Ku, K.Y. Lee, R.M. Edwards, pp 797-800 A new approach for wide-range optimal reactor temperature control using diagonal recurrent neuralnetworks (DRNN) with an adaptive learning rate scheme is presented. The drawback of the usual feedforward neural network (FNN) is that it is a static mapping and requires a large number of neurons. The usual fixed learning rate based on empirical trial-and-error schemes is slow and does not guarantee convergence. The DRNN is used for dynamic mapping and requires a much smaUer number of neurons and weights, and thus converges faster than an FNN. Rapid convergence of this DRNN-based control system is demonstrated by improved reactor temperature performance. 165 Trade-Off Between Energy Capture and Dynamic Loads in Variable Speed Wind Turbines T. Ekelund, B. Schmidtbauer, pp 801-804 This paper investigates the trade-off between the objectives of generating maximum power and minimizing the dynamic loads of a variable-speed wind turbine operated below rated wind speed. Linear quadratic optimal control methods are used to investigate this balance. Four models of different complexity are compared, and are established to have similar behaviour. The controllers have been simulated with a non-linear aerodynamic torque model, and the simulation confirms the predicted characteristics. It is also shown that the systems are robust to parameter changes, even
Machine learning can be used in the acquisition of knowledge for an operator assistant system. In applications such as fault diagnosis, the order of occurrence of event, may be impestant. In actual systems, noise is also present. Machine-learning algorithms for diagnostic knowledge should be capable of inducing knowledge reliably from noisy input, taking the sequence of events into account. This paper presents a method, based on genetic learning, which may be applied to the acquisition of a knowledge base for fault diagnosis. The algorithm is evaluated using a distribution system fault simulator.
168 A New Load Shedding Scheme for Limiting Underfrequency W.R. Lachs, D. Prasetijo, D Sutanto, pp 813-816 Under-frequency load shedding alleviates load-generation imbalance following a sudden loss of large amounts of generation. Loads are shed at pre-scheduied locations throughout the power system. It would be better if load shedding were to occur at locations close to the lost generation, thereby reducing the reactive power losses associated with transmitting larger amounts of power to the disturbed location. A new hierarchical load-shedding scheme is p .r.oposed, based on frequency, voltage and rate of frequency decline, which utilizes distributed intelligence to shed load according to the actual system state at each locality.
169 Control Options in Power System Operation by Use of Flexible AC Transmission System (FACTS) D. Sutanto, W.R. Lachs, pp 817-820 Devices known as FACTS (flexible AC transmission systems) specially designed to introduce more "flexibility" both in normal and emergency .operation of an electric Power system have been proposed in the hterature. The flexibility is related to the direct control (both local and centralised) of beth active and reactive power. The main aim is to increase the utilisation of existing facilities even to their thermal limits (without sacrificing reliability). This paper provides a review of the basic cxmcel~s and the possible FACTS options. It then proposes the use of battery energy storage plants for use in the FACTS system. The advantages and disadvantages are discussed.
170 CO2-Recoverlng Power Generation System in a CO 2Recycling Global Energy System Based on Solar Energy P.S. Pak, Y. Suzuki, Y. Tazaki, pp 821-824 This paper describes the concept of a CO2-recycling global energy system utilizing solar energy. The construction and characteristics of a CO2-recovering high-efficiency power-generation system are described in detail. In the power generation system, CO 2 gas is the working fluid of a closed-cycle gas-turbine power-generation system, and it is assumed that methanol is burnt in a combustor using oxygen. CO 2 gas included in the exhaust gas can be easily separated at the condenser oudet and mused m synthesize methanol. Gross thermal efficiency has been estimated at 54.6%. Net power generation efficiency has been estimated at 50.8% when considering the electric power required for liquefying recovered CO 2.