Overall fuzzy logic control strategy of direct driven PMSG wind turbine connected to grid

The fuzzy logic strategies reported in the literature about the control of direct drive permanent magnet synchronous generator (PMSG) connected to grid are limited in terms of inclusiveness and efficiency. So an overall control based on fuzzy logic and anti-windup compensation is proposed in this paper. Aiming at the inadequate of hill climb search (HCS) MPPT with fixed step size, the fuzzy logic is introduced in the stage of "generating rotor speed reference" to overcome the oscillations and slowness in traditional method. PI controllers are replaced by anti-windup fuzzy logic controllers in the "machine side control" stage and in "grid side control" stage to pertinently regulate the reference parameters. Then comparison tests with classical methods are implemented under varying climatic conditions. The results obtained demonstrate that the developed control is superior to other methods in response time (less than 4.528E-04 s), precision (an overshoot about 0.41%) and quality of produced energy (efficiency is 91%). The study verifying the feasibility and effectiveness of this algorithm in PMSG wind turbine connected to grid

Effect of loop delay on phase margin of first-order and second-order control loops

This paper analyzes the phase margin of first-order and second-order control loops in the presence of a loop delay and establishes rules of thumb on the maximum permissible delay for a given phase margin. Both discrete-time and continuous-time loops are considered. Results are applicable, for example, to adaptive filters and to first-order and second-order phase-locked loops

Effect of loop delay on phase margin of first-order and second-order control loops

This paper analyzes the phase margin of first-order and second-order control loops in the presence of a loop delay and establishes rules of thumb on the maximum permissible delay for a given phase margin. Both discrete-time and continuous-time loops are considered. Results are applicable, for example, to adaptive filters and to first-order and second-order phase-locked loops