1. 1. A NOVEL INTEGRATED AC/DC/AC CONVERTERS FOR DIRECT DRIVE PERMANENT MAGNET WIND POWER GENERATION SYSTEM by SHEELA AROKIA MARY . J M.E ( EMBEDDED SYSTEM TECHNOLOGIES) Under the Guidance Of Mr.S.Sivasakthi M.E., Associate Professor Head of the Department Department of EEE
2. 2. To reduce the switching loss & Minimize the circulating current in the power converters used in Wind power generation system and to improve the Power factor & overall performance of the system.
3. 3. 24 switches are used in Power converters. Separate stabilizing circuit is used Switching losses are high Presence of Harmonics are high
4. 4. 9 switches are used. Switching losses are reduced. Circulating current is minimized. Less harmonics. Power factor improvement is made.
5. 5. This proposed system has AC/DC/AC converter. In existing ac-ac converter topologies, 2 level 6 switch comprising a common dc link capacitor & VSI are frequently used In order to minimize the switching loss , we are implementing a topology of 9 switch USMC for wind energy conversion system. For rectification, a 3 switch Vienna rectifier is used.
6. 6. In inverter stage it employs an 6 switch VSI. Hence the number of switches & switching losses are reduced. The circulating current is minimized & Power factor improvement is made. As a result harmonics are reduced & overall efficiency is improved.
7. 7. PWM using PI Controller Technique.
8. 8. It converts wind energy into mechanical energy. Types horizontal axis wind turbine & vertical axis wind turbine. Efficiency & Power generation of wind turbine depends on increase in height of the tower & speed of the wind. Direct drive- Generator directly coupled with turbine.
9. 9. It converts the mechanical power output of wind turbine into electrical power. Principle-Faradays law of electromagnetic induction. Can be extremely large power ratings up to 1500MW They are known as synchronous machines because they operate at synchronous speed (speed of rotor always matches supply frequency)Ns=120 f/p. Instead of field winding, permanent magnet is used. Does not require DC supply, Condenser not needed. So output power is fully utilized and total loss is reduced, higher efficiency.
10. 10. 3 phase AC source LC Filter Solid state switches Diodes & capacitive circuits DC Link Micro controller based pulse signal
11. 11. Unidirectional 3phase AC/DC converter. 3 power switches. PF improvement Harmonics are reduced.
12. 12. 9 switches. Converts unstable AC to stable AC voltage. Switching loss is reduced Circulating current is minimized. Overall efficiency is improved.
13. 13. MATLAB- Simulink SOFTWARE REQUIREMENTS Microcontroller Inductor Controlled rectifier Inverter Gate driver
14. 14. Power factor Disadvantages of lagging power factor PF improvement equipments Power triangle
15. 15. This paper has comprehensively addressed the mimization of circulating current and switching losses. In this method the unstable AC voltage is converted to a stable AC voltage with power factor improvement. Experimental verification of the power converters confirms the good performance and promising features of the proposed directly driven permanent magnet wind power generation system.
16. 16. P.Goel,B.Singh,S.S.Muruthy,& N.Kishore,Isolated wind - hydro hybrid system using cage generators & battery storage,IEEE Trans.Ind.Electron., to appear. M.Liserre,R.Cardenas,M.Molinas,&J.Rodriguez,Overview of multi-MW wind turbines & wind parks,IEEE Trans.Ind.Electron.,vol.58,no.4,pp.1081-1095,Apr.2011. A.Rajaei,M.Mohamadian,S.M.Dehghan,&A.Yazdian,PMSG- based variable speed wind energy conversion system using rectifier,Euro. Trans.Electr.Power,vol,21,Jan 2011