Optimal design of UPFC nonlinear control system

In order to improve the control capabilities of power flow and system stability, unified power flow controller (UPFC) is widely studied. A nonlinear control system is designed in line with direct feedback linearization (DFL) theory and the excitation control system is taken into account. On the basis of the designed control system, a number of simulation researches are implemented which show that the nonlinear controller has much better performance than the linear.