Implementation and control of grid connected AC-DC-AC power converter for variable speed wind energy conversion system

30 kW electrical power conversion system is developed for a variable speed wind turbine system. In the wind energy conversion system (WECS) a synchronous generator converts the mechanical energy into electrical energy. As the voltage and frequency of generator output vary along the wind speed change, a DC-DC boosting chopper is utilized to maintain constant DC link voltage. The input DC current is regulated to follow the optimized current reference for maximum power point operation of turbine system. Line side PWM inverter supply currents into the utility line by regulating the DC link voltage. The active power is controlled by q-axis current whereas the reactive power can be controlled by d-axis current. The phase angle of utility voltage is detected using software PLL (phased locked loop) in d-q synchronous reference frame. Proposed scheme gives a low cost and high quality power conversion solution for variable speed WECS.

[1]  Control system design for a 20 kW wind turbine generator with a boost converter and battery bank load , 2001, 2001 IEEE 32nd Annual Power Electronics Specialists Conference (IEEE Cat. No.01CH37230).

[2]  R.W. De Doncker,et al.  Adjustable speed generators for wind turbines based on doubly-fed induction machines and 4-quadrant IGBT converters linked to the rotor , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).

[3]  A. G. Kothari,et al.  Unity power factor and efficiency control of a voltage source inverter-fed variable-speed induction motor drive , 2000 .

[4]  W. Koczara,et al.  Application of a permanent magnet machine in the novel Hygen adjustable-speed load-adaptive electricity generating system , 1999, IEEE International Electric Machines and Drives Conference. IEMDC'99. Proceedings (Cat. No.99EX272).

[5]  Peter Mutschler,et al.  The influence of control strategies on the energy capture of wind turbines , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).

[6]  Ying Hua Han,et al.  Grid Integration of Wind Energy Conversion Systems , 2000 .

[7]  Muneaki Ishida,et al.  An improvement of performance for small-scaled wind power generating system with permanent magnet type synchronous generator , 2000, 2000 26th Annual Conference of the IEEE Industrial Electronics Society. IECON 2000. 2000 IEEE International Conference on Industrial Electronics, Control and Instrumentation. 21st Century Technologies.