The Research On Control System Of Double Fed Induction Generator Based On PSCAD

Nowadays, energy shortage and environmental pollution is increasingly serious, so the development and utilization of renewable energy is extremely significance, wind power generation is one of the most mature technology, most scale development condition and the largest commercial prospects for development in the fields of renewable energy generation, to this, countries in the world competing for attention and develop. As the current mainstream technology, The variable speed constant frequency(VSCF) wind energy generation system with doubly fed induction generator(DFIG) realizes the flexible connection of mechanical and electric systems. The DFIG has the advantages of high wind-electric energy conversion efficiency and small size of the excitation converter. The advantages of efficient and economical make it an important study direction of wind power generation technology, and has good development prospects.In this paper, VSCF doubly fed wind power system control strategy is studied from theory to simulation mainly. Firstly, analyze the wind turbine and the doubly-fed wind power generation system based on the principle, establish a DFIG equivalent circuit model, and analyze the characteristics of the mathematical models of DFIG under different reference coordinate systems, Secondly, analyze the characteristics of rotor side exciter, namely dual PWM converter, establish mathematical models of grid side converter in different reference coordinate systems, study the vector control methods of grid side converter and SVPWM modulation realization in the PSCAD, Then, discuss the vector control technology of DFIG, according to the operation characteristics and the principle of wind turbine maximum power tracking, introduce the mathematical model of wind turbine in PSCAD and parameter selection method in detail, on this basis, according to stator flux oriented vector control strategy, use speed control mode and power control mode respectively, realized the maximum wind tracking, and active power, reactive power decoupling control,Lastly, according to the power system requirements of grid integration to large scale wind power, analysis the low voltage ride through technology and verified the DFIG can realize low voltage ride through in transmission line fault condition with the Crowbar over-current protection.