This paper presents a sensorless system drive on primary flux oriented control (PFOC) and secondary flux oriented control (SFOC) for the linear induction motor (LIM) with taking into account end effect. Extended kalman filter (EKF) is applied to estimate LIM speed by measuring motor voltages and currents. In order to achieve desirable dynamic and robustness motor performance instead of traditional PI controller, a fuzzy PI controller is used for speed regulation in LIM vector control. The accuracy and validity of fuzzy PI controller operation are investigated and evaluated and its results are compared with traditional PI controller. Transient and steady state responses of proposed controller under load thrust variations and speed command are studied. Also characteristics and performances of primary flux oriented control (PFOC) and secondary flux oriented control (SFOC) for the linear induction motor are compared with each other. In order to evaluate the proposed method, simulations are performed in MATLAB/SIMULINK. Results show that the fuzzy PI controller has more excellent performance than the traditional PI controller and also PFOC has better performance than SFOC, because SFOC depend on rotor resistance. EKF properly estimate motor speed by measuring motor voltages and currents and therefore speed sensor can be eliminated تفاصيل المقالة

Nowadays the position of the renewable energy is so important because of the environment pollution and the limitation of fossil fuels in the world. Energy can be generated more and more by the renewable sources, but the fossil fuels are non-renewable. One of the most important renewable sources is the wind energy. The wind energy is an appropriate alternative source of fossil fuel. The replacement rate of renewable energy to fossil fuels is rising, although the production cost is higher than fossil fuels. To further reduce cost of wind production, many methods have been proposed. One of the suitable approaches is the maximum power point tracking strategy. In this paper, a new intelligent maximum power point tracker called Fuzzy- Cuckoo strategy for small- scale wind energy conversion systems is proposed. The maximum power point tracker proposed uses measured wind speed to detect the maximum output power and its respective optimal rotational speed. The main contribution of the proposed approach is to exactly track the maximum power point, so the output power fluctuations captured by wind turbine are less than conventional approaches. The simulations are performed in MATAL/SIMULINK software. The superiority of the proposed approach is validated in two situations, low and rapid changes in wind speed. The maximum power point of wind energy conversion systems can be tracked by the proposed approach in any situation. The higher accuracy of the Fuzzy- cuckoo strategy than the conventional trackers is another advantage of the proposed approach. تفاصيل المقالة