A TSA-based consideration to design LQR auxiliary voltage control of DFIG

This paper introduces a consideration to design an auxiliary voltage control of doubly-fed induction generator (DFIG) using linear quadratic regulator (LQR). One of the LQR control design challenges is the state variables weighting matrix, which has lack of systematic method. The new consideration, that determines the LQR state weighting matrix, is based on the trajectory sensitivity analysis (TSA). TSA method solves the system differential algebraic equations to get the sensitivity of state variables and outputs to the system parameters. In this paper, the sensitivity of state variables to the DFIG voltage control input parameter is used to catch the state weighting matrix. The state weighting matrix is considered based on the infinity norm throughout the time series simulation. The proposed weighting matrix is compared with two of the common methods that used in literature using a modified two-area power system. Simulation results show that the TSA-based controller has better voltage support and control signal performance. The TSA-based controller also improves the settling of oscillation damping. The proposed method shows robustness of the damping control by presenting different contingency scenarios.