This paper shows that the capability of voltage-source converters (VSCs) to control the real power output of wind turbine generators (WTGs) can be applied to smooth power fluctuations due to wind turbulence. The paper calls attention to instability that can arise from: 1) the wind turbine itself and 2) the doubly fed induction generator (DFIG). The paper presents G P /V (s) to characterize the dynamic behavior of WTGs.Index Terms-Doubly fed induction generator (DFIG), decoupled P -Q control, filtering, frequency fluctuation, moment of inertia, smoothing, voltage-source converters (VSCs), wind farm, wind turbine generators (WTGs), wind power fluctuation.

Implementation of decoupled P -Q control of doubly fed induction generators requires the positions of the rotors to be known. The rotor position phase-lock loop (PLL) is an invention that extracts rotor position and speed simultaneously by "sensorless" means. The rotor position PLL is parameterinsensitive because, apart from an approximate value of the magnetization reactance, knowledge of the other parameters is not required for it to function. Experimental results obtained under noisy conditions demonstrate that it is also insensitive to noise.Index Terms-Decoupled P -Q control, doubly fed induction generator (DFIG), phase-lock loop (PLL), position encoder, renewable energy, wind turbine generators (WTGs), wound rotor induction machine.

This paper presents an invention, the rotor position phase lock loop (PLL), which enables maximum power point (MPPT) tracking of wind by doubly-fed induction generators without needing a tachometer, an absolute position encoder, or an anemometer. The rotor position PLL is parameter variation insensitive, requiring only an estimate of the magnetization inductance for it to operate. It is also insensitive to noise in the electrical measurements. Proof of concept is by: 1) digital simulations and 2) experimental testing of a laboratory prototype. Index Terms-Decoupled -control, doubly-fed induction generator (DFIG), maximum power point tracking, wind turbine generator (WTG).

No abstract

No abstract