Nonlinear L2 disturbance attenuation control design of UPFC for power flow control

A nonlinear L
₂
disturbance attenuation control (DAC) of unified power flow controller (UPFC) is investigated in power system by using Hamiltonian function method. First, the dissipative Hamiltonian structure of the UPFC system is established by means of variable transformation. Then, based on the obtained dissipative Hamiltonian structure, a nonlinear L
₂
DAC is put forward. Simulation results on the two-area four-machine power system demonstrate the effectiveness and robustness of the nonlinear L
₂
DAC in comparison with that of direct feedback linearization control (DFLC) and add-On self-tuning (ST) control and PI control. The research results show that the nonlinear L
₂
DAC has better performance than the other controls.