Kazemi M.V.,Institute for Higher Education |
Moradi M.,Islamic Azad University |
Kazemi R.V.,Islamic Azad University
COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering | Year: 2014
Purpose - A direct power control (DPC) of the doubly-fed induction generator (DFIG) is presented. A new method, which is based on the rotation of the space sector, clockwise or vice versa, is proposed to improve the performance of the switching table. Then, it is combined with a fuzzy system to have advantages of both rotation sector and fuzzy controller. The paper aims to discuss these issues. Design/methodology/approach - In this paper, a new DPC of the DFIG is presented. To improve the performance of the switching table, a new method is proposed. The method is based on the rotation of the space sector, clockwise or vice versa. The excellence of the proposed method is proven. Then, it is shown that the performance of the system can be enhanced by using a fuzzy logic controller. The rotation method is combined with a fuzzy system. Findings - Simulation shows that although sector rotation and fuzzy controller can improve the performance of the DFIG, a combination of both demonstrates a smoother response in order that reactive and active power ripples and THD of the injected current decrease in different speeds. Also, it is demonstrated that the proposed method is robust against parameters variations. However, a hardware experiment should be performed to be practically verified. Originality/value - A sector rotation is proposed and its effect on the performance of the DFIG is considered. A simple method to write rules table is presented and the performance of sector rotation and fuzzy controller on the DFIG is analysed. Copyright © 2014 Emerald Group Publishing Limited. All rights reserved.
Verij Kazemi M.,Institute for Higher Education |
Moradi M.,Islamic Azad University |
Verij Kazemi R.,Islamic Azad University
Electric Power Systems Research | Year: 2012
This paper presents a new direct power control (DPC) strategy for a double fed induction generator (DFIG) based wind energy generation system. The strategy of the discrete space vector modulation (DSVM) that is on the basis of the DPC, is implemented. The algorithm to select voltage vector can effectively change the response of the system. So, a new analysis is done and a new switching table is proposed. The proposed switching table is presented to optimize the performance of the voltage vectors by accurately designing the sequence of the voltage vectors. Rearranging the sequence of the voltage space vectors has an influence on active power ripple. To enhance the performance of the closed loop system, fuzzy system is proposed in place of the switching table and hysteresis system. The four variables, rotor speed, errors of the active and reactive powers and stator flux position are exerted to the fuzzy system and the output is the vector that should be implemented to the switching devices. The outperformance of the proposed method is demonstrated by performing simulations in Matlab Software. © 2012 Elsevier B.V. All rights reserved.
Kargaran E.,Institute for Higher Education |
Mafinejad Y.,Deakin University |
Mafinezhad K.,Institute for Higher Education |
Nabovati H.,Institute for Higher Education
IEICE Electronics Express | Year: 2013
In this paper, a new gain enhancement technique which is recommended for folded cascode LNA structures at low voltage and low power applications is presented. In order to increase power gain, a new modified version of gm-boosting technique is employed which increases the power gain while consuming no extra power. The new topology shares its DC current at the folded stage in order to reduce power dissipation associated with the gm-boosting technique. The proposed technique reduces power dissipation almost 27%, additionally; other parameters such as power gain and noise figure have been slightly improved. In the proposed LNA, power gain and noise figure are15 dB and 3.2 dB respectively. It consumes 1.3mW under 0.6 supply voltage. © IEICE 2013.