Hierarchical micro-genetic algorithm paradigm for automatic optimal weight selection in H∞ loop-shaping robust flexible AC transmission system damping control design

A hierarchical-micro-genetic-algorithm-(H-μGA)-based strategy is presented for suitable weight selection in H_∞ loop-shaping robust damping control of flexible AC transmission system (FACTS) devices via normalised coprime factorisation. In H_∞ robust control design, the selection of a weighting function is an arduous and time consuming task. To muddle through this dilemma, an HGA in liaison with a micro-GA is employed to simultaneously select an appropriate structure and parameters of the weighting function in order to achieve a desired performance without the usual trial and error practice. To evaluate the effectiveness of the proposed technique, H_∞ robust damping control systems for SVC and TCSC are investigated and compared with the classical H_∞ loop- shaping control systems design. The performance and robustness of the proposed FACTS damping controls are validated through small signal and large signal simulations in a multi-machine power system.