Emergency DC power control strategy for quickly suppressing inter-zone disturbance based on time-optimal control theory
基于时间最优的快速平息区间扰动的紧急直流功率控制策略

Based on the equivalent-two-machine-two-area AC/DC parallel system, a time optimal control(TOC) plan for a second-order oscillation system is developed and a TOC strategy for quickly suppressing interzone disturbance is proposed. Firstly, the TOC theory is introduced to drive system states to a post-fault equilibrium point, and then, the nonlinear control theory is used to hold the states in that equilibrium point. Switching curve is also improved to avoid DC power jump-changing and to eliminate high-frequency nonlinear chattering and overshooting, and the optimal amount of DC power controlled by a minimal number of switching is derived. The simulation results show that the proposed TOC strategy can be combined with the practical DC Emergency Run-up and Run-back control functions to quickly and effectively suppress the interzone oscillation after a first angle swing.