A Dsp Based Experimental System For Wind Turbine

As human society for the 21st century, the rapid development of industry leads to more and more serious energy issues and in the future decades, some of the conventional energy sources we use now will exhausted. So study of renewable energy such wind energy becomes a major issue at this stage of research. With the capacity of wind power generation system increased, some of the experiments in the process of study can not be completed at the wind spot which makes the simulation of wind power generation system become the important way for its study. VSCF doubly fed wind energy generation experimental system and its control technology is studied in this thesis.This thesis originated from a high-power converter experimental project of the VSCF AC excitation doubly fed wind energy generation system. We research and improve the working characteristics of converter using two double-fed motors in the experimental system by simulating various wind conditions and set up a platform for the subsequent active power, reactive power control and LVRT experiments.In this thesis, we study the converters of both motor side and grid side and focus on the motor side converter. First, the theoretical analysis and experimental verification shows that the open-loop speed control of VVVF control characteristics and control effects. Second, according to the dynamic model of induction motor and the analysis of the relationship between current and flux, we propose a rotor flux oriented vector control scheme of the induction motor, then simulate this kind of vector control using MATLAB / SIMULINK. The effect from the rotor parameters on this control system with high dynamic performance is basically eliminated. Finally, two control schemes are analyzed.In this thesis, some major aspects of research on the experimental system are carried out. In VVVF control scheme, the voltage and frequency do not demonstrate a strictly proportional relationship but show an S-type curve, hence in low frequency, the voltage needs some compensation and this paper has theoretically and experimentally determined the compensation voltage at low frequencies. In the vector control, to achieve the rotor flux oriented VC system, the key factor is to obtain the rotor flux for the flux feedback signal and the division link utilization, but direct detection methods such as flux tank buried in the motor coil has a lot of technology and technical problems, making detection of the signal pulse with a larger quantity of harmonic and the lower speed the more serious, so this paper using the indirect method obtain the rotor flux amplitude and phase.