22 research outputs found

    Višefazni sustav za pretvorbu energije vjetra zasnovan na matričnom pretvarač

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    Abstract: This paper presents a new variable speed wind energy conversion systems (WECS). It is based on a six-phase asymmetrical squirrel cage induction generator (SCIG) and a matrix converter (MC) as power electronic interface between six-phase SCIG and electrical network. The analysis employs a rotor flux vector control algorithm and a scalar strategy modulated MC to control the generator. Characteristics of MC are used for maximizing the power tracking control when different wind speeds and delivering powers to the grid are simultaneously considered. The MC provides sinusoidal input and output voltages and a unity power factor, but causes an asymmetry in the generator. A current control strategy including the method of suppressing imbalance caused by this asymmetry is discussed. Some numerical simulations are carried out showing the effectiveness of the proposed WECS topology.U ovom radu prikazan je novi sustav za pretvorbu energije vjetra s promjenjivom brzinom. Zasnovan je na šestofaznom asimetričnom kaveznom generatoru i matričnom pretvaraču koji je sučelje između generatora i elektroenergetske mreže. U analizi se koristi vektorsko upravljanje tokom u rotoru i skalarna strategija moduliranog matričnog pretvarača za upravljanje generatorom. Karakteristike matričnog pretvarača koriste se za maksimiziranje slijeđenja snage u slučajevima kada se istovremeno promatraju različite brzine vjetra i snage koja se daje u mrežu. Matrični pretvarač daje sinusni ulazni i izlazni napon te jedinični faktor snage, ali uzrokuje asimetriju u generatoru. Razmotrena je strategija upravljanja strujom koja uključuje metodu za smanjivanje neravnoteže koju uzrokuje asimetrija. Provedene su numeričke simulacije koje pokazuju efektivnost predložene topologije sustava za pretvorbu energije vjetra

    Extended Kalman filter based sliding mode control of parallel-connected two five-phase PMSM drive system

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    This paper presents sliding mode control of sensor-less parallel-connected two five-phase permanent magnet synchronous machines (PMSMs) fed by a single five-leg inverter. For both machines, the rotor speeds and rotor positions as well as load torques are estimated by using Extended Kalman Filter (EKF) scheme. Fully decoupled control of both machines is possible via an appropriate phase transposition while connecting the stator windings parallel and employing proposed speed sensor-less method. In the resulting parallel-connected two-machine drive, the independent control of each machine in the group is achieved by controlling the stator currents and speed of each machine under vector control consideration. The effectiveness of the proposed Extended Kalman Filter in conjunction with the sliding mode control is confirmed through application of different load torques for wide speed range operation. Comparison between sliding mode control and PI control of the proposed two-motor drive is provided. The speed response shows a short rise time, an overshoot during reverse operation and settling times is 0.075 s when PI control is used. The speed response obtained by SMC is without overshoot and follows its reference and settling time is 0.028 s. Simulation results confirm that, in transient periods, sliding mode controller remarkably outperforms its counterpart PI controller
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