Research On Modulation Stategy For Paralled Back-to-Back PWM Wind Converter

Wind power technology has been increasingly emphasized on research, which uses a wind turbine directly to drive permanent magnet synchronous motor, Converts electricity to grid through power converter, eliminates the frequent failure gear box, what's more, improves the low pressure through ability and enhances efficiency significantly. Therefore, direct drive wind power generation is an important direction in wind power technology. However, full power converter carrying all the power. With the capacity of stand-alone wind power increasing, to the improvement of the full power converter capacity will be the focus of the study in wind power converter technology, the goal is to improve the capacity of the converter, protect the power converter operating stably and efficiently, to provide high-quality power to the grid, which has a profound impact the development of wind power.This paper applied the phase shift carrier technology in high-power converter, to achieve the capacity of full power converter increase, unfolded the following work:The paper introduced the development of domestic wind power industry history and current situation, the focus of wind power converter status and development trends, summed up the converter to improve the capacity of viable options, focusing on the status of technology research in parallel, indicating that the parallel technology to improve converter capacity is feasible.Secondly, it analyzed the mathematical model of 6-phase permanent magnet synchronous motor and the wind turbine, built the directly connection simulation model of the wind turbine and permanent magnet synchronous motor. Additionally, explained the permanent magnet synchronous motor zero d-axis air strategy and.Verified the effectiveness of the control strategy.Thirdly, it analyzed and compared several high-power converter modulation strategy, focused on Carrier Phase Shifted SPWM and Carrier Phase Shifted SVM modulation, which are outstanding high-power converter technology modulation strategy. In addition, the paper modulated waveform via two modulation strategies basing on MATLAB/SIMULINK.Finally, the paper focused on the parallel back-to-back PWM converters topology and operating conditions, Researched grid-side converter and generator-side converter model of the parallel back-to-back PWM converters, generator-side converter was applied the inner current loop and outer voltage loop control strategy, network-side converter used voltage and current double-loop for Decoupled Active and Reactive Power control strategy. On this basis, two kinds pulse width modulation simulation model was built, and compared two simulation results, verified the advantages and disadvantages of each high-power modulation strategy. For Carrier Phase-Shifting Technique being used in Pulse Width Modulation, achieved an aim application of pulse width modulation in High-Power Converter technology occasions. The simulation waveform verified feasibility of the study.