On-Line Recursive Closed-Loop Subspace Identification for Power System Damping Control
Ye Hua Liu Yutian (Shandong University Jinan 250061 China)
On-line recursive closed-1oop subspace algorithm is proposed for state space model identification in power system damping control. Under closed-loop condition and based on wide-area measurements, reduced order state space model of the system which contains dominant low frequency oscillation modes is identified on-line. Then linear quadratic optimal part output supplementary inter-area damping controllers are designed and updated to damp the inter-area low frequency oscillation modes. The algorithm has good numerical stability and low time complexity so that system model can be recursively updated and parameters of the controller can be adjusted on-line. Simulation results of the China EPRI 8-machine 36-bus system demonstrate that the effectiveness of the algorithm.