Co Ordinated Multiloop Switching Control of DFIG for Resilience Enhancement of Wind Power Penetrated Power Systems
This paper proposes a co ordinated four loop switching controller (SC) for the doubly fed induction generator (DFIG) to improve the transient stability of wind power penetrated power systems. A short term resilience index is introduced, and it reflects the dynamics of both system frequency and load bus voltage. A four loop SC is driven by the four outputs of a DFIG, namely, the rotor speed deviation, the reactive power output of stator winding, the reactive power transferred through grid side converter, and the DC link voltage, respectively. Referring to a state dependent switching strategy, the four loop SC switches between a logic based bang bang constant funnel controller (LBCFC) and a vector control theory based conventional controller (CC) in each control loop. The LBCFC is robust to system nonlinearities, uncertainties, and external disturbances. The control signal of the LBCFC is bang bang with the upper and lower limits of control variables. Simulation studies are undertaken in a modified IEEE 16 generator 68 bus power system, in which four DFIG based wind farms are penetrated to provide 9.94% power supply. The performance of the four loop SC is evaluated in aspects of the integral control of the DFIG and the resilience enhancement of the multimachine power system, respectively.
IEEE Transactions on Sustainable Energy