变速恒频无刷双馈风电机组的励磁电源研究

Study on excitation source of variable-speed constant-frequency brushless double-fed wind power generators

基于同步坐标下的无刷双馈电机的数学模型,研究变速恒频无刷双馈风电机组的矩阵变换器式交流励磁电源,提出了矩阵变换器的SPWM调制策略,并验证了矩阵变换器可以满足无刷双馈风电机组的运行条件。将矩阵变换器与电压型双PWM控制交-直-交变频器从响应速度和谐波含量方面,进行了详细的分析比较。在相同情况下,采用矩阵变换器励磁时,响应速度优于电压型双PWM交-直-交变换器。对矩阵变换器交流励磁变速恒频无刷双馈风电机组进行仿真分析,发电机组输出电流的谐波含量少。

According to the mathematical model of the VSCF brushless doubly-fed generator in synchronous coordinates, the paper studies matrix converter AC excited power of variable speed constant frequency brushless double-fed wind generators, puts forward SPWM controlling strategies of matrix converters, and verifies the operational conditions of matrix converters that can meet the demands of brushless double-fed wind generator; then makes a thorough comparison between matrix converters and voltage dual PWM AC-DC-AC converters from the aspects of response speed and harmonic content. Under the same circumstances, when matrix converter is adopted to be the excitation, the response speed is faster than that of dual PWM AC-DC-AC converter. In addition, through the simulation analysis of matrix converter AC excited variable speed constant frequency brushless double-fed wind generators, the study finds that the harmonic content of the output current is small.