Power

This paper presents the performance evaluation of Doubly-Fed Induction Generator Using Combined Vector Control and Direct Power Control Method. Combined vector and direct power control (CVDPC) is used for the rotor side converter (RSC) of double-fed induction generators (DFIGs). The control system is according a direct current control by selecting suitable voltage vectors from a switching table. Actually, the proposed CVDPC encompass the benefits of vector control (VC) and direct power control (DPC) in a compact control system. Its benefits compare with VC contains rapid dynamic response, Stability against the machine parameters Changes, less computation, and naive implementation. On the other hand, it has benefits compared with DPC, contains less harmonic distortion and lower power ripple. This technique is to improve the dynamic performance of the DFIG driven by the wind-energy conversion system.

In modern power system the non-renewable sources of energy are being replaced by renewable sources of energy such as wind, solar and hydro due to their advantage of pollution free and clean environment. But with the use of renewable sources of energy, the power system undergoes many problems, one of which is the voltage stability problem arising during grid integration. This problem can be overcome by using FACT devices such as STATCOM. This paper analyses the role of STATCOM in improving the voltage stability DFIG based wind farms located at different places which are connected to the grid. The STATCOM compensates the reactive power at the point of common coupling and thus improves the voltage and protects the system during grid faults. MATLAB/SIMULINK is used for simulating the developed system and results show that STATCOM improves the voltage and maintains the uninterrupted operation of the grid during grid fault.

Wind power stations, many located in remote areas; so they are characterized by weak grids and are often submitted to power system disturbance like faults. In this paper, the behaviour of a wind energy conversion system that uses the control of the rotor side converter (RSC) by three different methods under faulty conditions is presented. The behaviour of these systems during a grid failure is an important issue. DFIG is analysed and simulated under differing faulty conditions in the environment of MATLAB/SIMULINK. Simulation results show that the proposed method has proper operation during fault conditions.

— at the moment the position of the renewable energy is so important because of the environment pollution and the limitation of fossil fuels in world. Energy can be generated more and more by the renewable sources, but the fossil fuels are nonrenewable. 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 above fossil fuels. To further reduce cost of wind production, many methods have been proposed. One of the appropriate methods is the maximum power point tracking strategy. In this paper, tip speed ratio control is first applied for maximum power point tracking. Then, speed sensor less algorithm is used to avoid the measurement of actual values. And TSR control is still used to test the estimate accuracy. Based on the two methods, fuzzy based hill climbing method is designed. The computer simulations with a 8 KW wind power generation system are performed. The results of simulation from the proposed control method are compared with those obtained using the two existing methods. The proposed method generally outperformed the two existing methods, especially when the operating point is far away from the maximum point. The control method also has similar stable characteristic when the operating point is close to the peak point in comparison with existing methods. The proposed fuzzy method is computationally efficient and can be easily implemented in real-time.

انرژی باد یکی از انرژی های تجدید پذیر است که به دلیل
ویژگی های تمیز و اقتصادی آن توجهات را بسوی خود جلب کرده است، و
پیش بینی می شود که تا سال 2020 تا 12 ٪ از انرژی برق توسط انرژی باد
تامین شود. توربین های بادی به دو دسته طبقه بندی می شوند: توربین های
سرعت ثابت و توربین های سرعت متغییر. برای توربین های بادی سرعت
ثابت ، ژنراتور القایی به طور مستقیم به شبکه الکتریکی وصل است و سرعت
روتور ثابت و یا دارای تغییرات بسیار کمی با سرعت باد است. امروزه
توربین های بادی سرعت متغیر شایع تر از توربین های سنتی سرعت ثابت
است ان هم به دلیل تولید انرژی کارآمد تر، کیفیت توان بهبود یافته و بهبود
عملکرد دینامیکی در طول اختلالات شبکه. علاوه بر این، آنها می توانند تنش
های مکانیکی توربین های بادی سرعت ثابت را کاهش دهند. به تازگی
تبدیل ماتریسی در ساختار DFIG استفاده می شود. تبدیل ماتریسی متشکل
از نه سوئیچ دو طرفه است که اتصال هر فاز ورودی به فازهای خروجی را
بدون خازن لینک DC قادر می سازد. با این حال تبدیل ماتریسی به تغییرات
ویژگی های توپولوژیک حساس هستند. مبدل نه سوئیچی جدید به تازگی به
عنوان رقیب جایگزین برای مبدل پشت به پشت PWM ارائه شده است. که
در این مقاله یک استراتژی کنترل برای ژنراتور القایی دوسو تغذیه ) DFIG )
با استفاده از توپولوژی اینورتر یکسوساز، که متشکل از تنها نه سوئیچ
الکترونیک قدرت IGBT برای تبدیل AC / AC از طریق لینک DC است
ارائه می شود. در مقایسه با مبدل AC / AC پشت به پشت معمولی، تعداد
سوئیچ های نیمه هادی قدرت در تبدیل پیشنهادی کاهش می یابد. توپولوژی
پیشنهادی منجر به کاهش ناحیه نصب و راه اندازی و هزینه می شود. اصول
عملکرد، استراتژی کنترل و ویژگی های توربین بادی بر اساس مبدل AC / AC پیشنهادی در این مقاله توضیح داده می شود. نتایج شبیه سازی نشان می
دهد که حتی اگر تغییرات سرعت باد رخ دهد ولتاژ ترمینال ژنراتور و فرکانس
مشابه حات قبلی سرعت ثابت باقی می ماند. توان خروجی ژنراتور هم
متناسب با تغییرات سرعت باد توان بیشتری به شبکه تحویل می دهد.

1 ] ‫اؼننٍ‬ ‫طقاصظدل‬ ‫غ‬ ‫اّ‬ ‫ط‬ ‫ٔذ‬ ‫ق‬ ‫ا‬ ‫يحذِد‬ ‫احو‬ ‫ِطحذ‬ ‫ٔی‬ ‫خیِجر‬ ‫ذر‬ ‫طسرو‬ ‫رظل‬ ‫طَا‬ ‫اهارظ‬ ِ ‫ػرظر‬ ‫ٔظل‬ ‫خّطسآ‬ ‫ط‬ ‫ر‬ ‫ٕظ‬ ‫دٓ‬ ‫دٔذ‬ ‫َانجٓ‬ ‫رط‬ ‫سنساى‬ ‫ط‬ ‫ػیدطرل‬ ‫ػٕیْ‬ ِ ‫سّخو‬ ‫در‬ ُٓ ‫ٔز‬ ٍ ‫دًای‬ [ 3 ] ‫سرظنٕظ،‬ ٍ ‫ط‬ ‫طّل‬ ‫در‬ ‫ارالش‬ ‫در‬ ‫پؤِطرٕظ‬ ‫ط‬ ‫ػسرنظرل‬ ‫إظ،‬ ‫يحذِد‬ ‫يخاهف‬ ‫طَّطع‬ ‫نیل‬ ‫ػکظر‬ ‫ػظ‬ ‫يطکال‬ ‫حم‬ ‫ػیطل‬ ‫ر،‬ ‫ظ‬ ‫ر‬ ‫زل‬ ‫ر‬ ‫ػیَظيٓ‬ ‫سظ‬ ‫ػٕنُٓ‬ ‫اکُنکٕظل‬ ِ ‫ػظر‬ ‫طقاصظدل‬ ‫غ‬ ‫اّ‬ ‫ل‬ ‫طسو‬ ‫ضذْ‬ ‫يُاطی‬ ‫اليؼرذط‬ ‫اکیطر‬ ‫رِش‬ ‫ضظيم‬ ‫يؼًّنر‬ ‫ظ‬ ‫دالسنر‬ ‫رِضٕظل‬ [ 2 ] ‫پیِجکطرٍ،‬ ‫رظٌ‬ ‫یطد‬ ‫اى‬ ‫،طنگرّر‬ ‫طرٓ‬ َ ‫رِش‬ ‫دطخهر‬ [ 3 ] ، ‫خطر‬ ‫زل‬ ‫ر‬ ‫ػیَظيٓ‬ [ 4 ] ، ‫اکظيهر‬ ‫ایطَسنم‬ ‫د‬ [ 10 ] ‫ُظينکر‬ ‫د‬ ‫زل‬ ‫ر‬ ‫ػیَظيٓ‬ ِ [ 5 ] ‫طسرو‬ ‫ضرظيم‬ ‫ٔرى‬ ‫يرذرٌ‬ ‫رِضرٕظل‬ ‫اکظيهر‬ ‫زل‬ ‫ر‬ ‫ػیَظيٓ‬ [ 8 ] ، ‫ژَانر‬ ‫اى‬ ‫طنگّر‬ [ 7 ] ، ‫ط‬ ‫ل‬ ‫سظ‬ ‫ػٕنُٓ‬ ‫ررط‬ ‫دحظو‬ [ 6 ] ، ‫ػسرم‬ ‫َؼّر‬ ‫دهَّر‬ ‫رِش‬ [ 9 ]

In this paper Combined Vector and direct power control (CVDPC) strategy is applied to control a doubly fed induction generator (DFIG) based wind energy generation system. AC/DC/AC converter is controlled by Combined Vector and direct power control method. The rotor side converter is controlled by selecting appropriates voltage vector based on the instantaneous errors between the reference and estimated values of active and reactive powers and rotor flux position. Also the Grid side is controlled by Combined Vector and direct power control based a grid voltage position to ensure a constant DC voltage, Simulation results demonstrate robust, precise, and fast dynamic behavior of the system.

Wind power stations, many located in remote areas; so they are characterized by weak grids and are often submitted to power system disturbance like faults. In this paper, the behaviour of a wind energy conversion system that uses the control of the rotor side converter (RSC) by three different methods under faulty conditions is presented. The behaviour of these systems during a grid failure is an important issue. DFIG is analysed and simulated under differing faulty conditions in the environment of MATLAB/SIMULINK. Simulation results show that the proposed method has proper operation during fault conditions.