直驱风电系统三电平变流器的设计与仿真

多电平逆变器适合大容量、高压的场合，得到了越来越多的应用。本文对三电平逆变器SVPWM调制手段进行了深入研究,同时对三电平逆变器中点电位平衡的问题也进行了探讨。由于中点电位的不平衡是钳位式三电平逆变器运行过程中比较严重的问题，对此本文分析了大、中、小矢量对中点电位的影响，找到哪些矢量能够影响中点电位的波动，并得出通过对成对小矢量的作用时间分配能够控制中点电位的结论。最后通过对系统的仿真，验证了算法的可靠性。

Design and Simulation of Directly Drive Wind Power System with Three Level Converter

The theory of operation of direct driven permanent magnet synchronous generator is analyzed, and the mathematical model of a permanent magnet double PWM control for direct drive wind power generation system is established . This is the machine side of generator rotor field oriented vector control method based on the converter, the efficiency of the generator is improved. For the control of grid side inverter, the double loop control strategy of DC voltage loop and inactive current inner loop is used, and the objectives to the DC power inverter with the same frequency and amplitude of the AC can be achieved. Last the system simulation model by means of Matlab/Simulink is established, and the simulation research carried out. The simulation results prove the theoretical analysis is correct. It is a significant guidance for experimental research on the system.