Browsing by Author "Zhang, Y."

Now showing 1 - 3 of 3
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    Design of a Robust Speed and Position Sensorless Decoupled P-Q Controlled Doubly-Fed Induction Generator for Variable- Speed Wind Energy Applications
    (IEEE, 2007-10) Gogas, K.; Joos, G.; Ooi, B. T.; Mwinyiwiwa, Bakari M. M.; Zhang, Y.
    This paper proposes an implementation of a decoupled P-Q control of a DFIG that does not rely on mechanical sensors and a speed and position sensorless algorithm that is robust to variations of the values of the machine parameters. In this paper, the sensorless control is based on a modified phase-locked loop with an improved positioning algorithm. This eliminates the need to estimate the speed based on the machine parameters, which results in a significant improvement in speed control robustness to parameter variations. In addition, the algorithm avoids using differentiation which can lead to significant inaccuracy due to the noise inherent in measured signals. Theoretical and simulation results were validated on an experimental setup, using a laboratory 5 hp DFIG.
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    Rotor-Position Phase Lock Loop for Decoupled P-Q Control of DFIG for Wind Power Generation
    (IEEE Transactions on Power Electronics, 2009) Mwinyiwiwa, Bakari M. M.; Shein, B.; Zhang, Y.; Ooi, B. T.
    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 parameter-insensitive 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.
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    Sensorless Maximum Power Point Tracking of Wind by DFIG Using Rotor Position Phase Lock Loop (PLL)
    (IEEE Transactions on Power Electronics, 2009) Shein, B.; Mwinyiwiwa, Bakari M. M.; Zhang, Y.; Ooi, B. T.
    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.