Multi-objective robust tuning of STATCOM controller parameters for stability enhancement of stochastic wind-penetrated power systems

This study proposes a robust optimisation method for controller parameter tuning of Static Synchronous Compensators (STATCOMs) to enhance the stability of a wind-penetrated power system. The uncertainties of the wind power output and the pre-contingency state of STATCOMs, which both have a significant impact on the solutions, are addressed. Firstly, a novel index is proposed to quantify the robust optimality of the solutions, which is the sensitivity of solution results to the variations of the potential uncertainties. Then, a multi-objective robust optimisation model is proposed to simultaneously optimise three objectives: (i) short-term voltage stability index, (ii) transient (rotor angle) stability index, and (iii) robustness of the solutions. Finally, an improved non-dominated sorting genetic algorithm-II is developed with (1) Latin hypercube sampling-based initial generation, and (2) adaptive mutation rate. The proposed method is tested on a modified New England 39-bus system with industry-standard models and recommended model parameters. Simulation results verify that the much higher computational efficiency and the stronger robustness of the proposed method over conventional methods.