Nonlinear control algorithms and power system application

摘要

Two distinct approaches to design of nonlinear control systems are discussed in context of stabilization of interconnected power transmission systems. The control problem considered involves manipulation of line impedance through thyristor controlled series capacitor to increase stability of the transmission system in case of a large fault. Since the control signal affects system dynamics multiplicatively, traditional linear control strategies are found not appropriate and nonlinear techniques must be used instead. The first method considered is a self-tuning predictive controller based on bilinear model structure. The algorithm is shown to quickly identify the system dynamics and effectively damp oscillations following a simulated fault. The second method is a neural-network-based hierarchical controller using simplified models of the system and off-line training to classify and interpolate between different operating conditions of the system. Both nonlinear controllers are based on a concept of optimization of a performance criterion and naturally incorporate limits on control signals.