In this paper a WECS (Wind Energy Conversion System) based on a PMSG (Permanent Magnet Synchronous Generator) and implementing a sensorless MPPT (Maximum Power Point Tracking ) strategy is presented using three types of generator rotor speed and angle estimators; the Angle Tracking Observer, the Extended Kalman Filter and the Synchronous Reference Frame Phase Locked Loop. The main purpose is to compare these estimators. Simulation results in Matlab-Simulink allowing this comparison can be found at the end of this work.
Słowa kluczowe: generator synchroniczny z magnesami trwałymi PMSG, bezczujnikowe śledzenie maksimum mocy MPPT
W artykule opisano generator z magnesami stałymi PMSG wykorzystujący strategię MPPT (śledzenie maksimum mocy). Porównano trzy typy estymatorów prędkości i kąta obrotu wirnika: czujnik kąta obrotu (angle tracking observer), filtr Kalmana i synchroniczną pętlę fazową (synchronous frame phase locked loop).
Keywords: WECS, Direct-drive PMSG, sensorless MPPT, SRF-PLL, EKF, ATO, FOC, Extremum seeking
Wind energy is one of the prominent renewable energy sources on earth. The global trend of recent research in this field is to minimize the overall cost of the Wind Energy Conversion System (WECS) while improving the quality of the produced power. With this aim, several works have been carried out to avoid the use of the mechanical sensors which are expensive to buy and maintain. The principal role of the sensors is measuring the generator rotation speed as well as the angle of the rotor that are necessary for the control of the system and the search of the maximum points of the extractable power. Reliability of the variable speed wind turbine can be improved significantly using a directdrive Permanent Magnet Synchrounous Generator (PMSG) . A sensorless Maximum Power Point Tracking (MPPT) strategy is proposed to control the pre-mentioned structure, it consists of two levels; the first is a power regulation loop generating the reference value of current iqref to the Field Oriented Control (FOC)  justified by a power maximization analysis. The second level is the extremum seeking method  generating the optimum value of the coefficient including turbine parameters in the expression of the turbine output power. The main objective of this paper is to compare three types of estimators used to build the sensorless MPPT. The first estimator is an Angle Tracking observer (ATO) , the second is the Extended Kalman Filter (EKF)  and the third is the Synchronous Reference Frame Phase Locked Loop (SRF-PLL) . The global wind conversion chain is presented in Fig.1. Simulation results obtained using Matlab-Simulink and allowing the comparison of the three estimators can be found at the end of this paper. In the conclusion we evaluate performance of the three estimators and give their basic advantages and disadvantages. Global system modeling The wind conversion chain considered in this work is presented in Fig.1 consis [...]
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