双电压合成的无刷双馈风力发电系统矩阵变换器励磁控制

Control of the Brushless Doubly-fed Wind Generator System Excited by Matrix Converter with Line-to-line Voltages Synthesis

为实现双馈型风力发电系统的变速恒频运行控制,构建了能量能够双向流通的励磁装置。矩阵变换器(MC)输出电压的频率、幅值、网侧功率因数可控,通过调节矩阵变换器输出电压频率,改变无刷双馈风力发电机控制绕组的电压频率,从而保证功率绕组输出电功率的频率稳定为工频。矩阵变换器采用双电压合成控制策略,控制电机的转速和功率因数;数字信号处理器应用双电压控制算法、复杂可编程逻辑器件实现4步换流方法,为矩阵变换器的双向开关提供PWM驱动控制信号。基于MatlabR2007a平台构建了MC励磁控制的无刷双馈变速恒频风力发电系统模型,通过实验室搭建的一套实际无刷双馈风力发电机组实验平台进行了相关实验,仿真和实验结果保持了较好的一致性,验证了控制方案的有效性,同时为矩阵式变换器的实际应用提供了理论和实验基础。

In order to realize control of the doubly-fed wind power generator system in variable-speed constant-frequency （VSCF） operation, the excitation device of generator system must possess the capability of bi-direetion flow power. Consequently,the matrix converter （MC） was selected to control the frequency of voltage of the control windings of brushless doubly-fed machine （BDFM） by regulating the frequency of output voltage of the MC. And the frequency of voltage of the power windings of BDFM was maintained to grid frequency. The speed and power factor of BDFM were controlled by the MC with line-to line synthesis voltages strategy. The PWM drive signals were provided to the bi-direction switches of MC by the digital signal processor （DSP） with hne-to-line voltages syn- thesis algorithm and the complex programmable logic device （CPLD） with four-step commutation. The model of VSCF brushless doubly-fed wind power generator system excited by MC was constructed in Matlab R2007a. A practical prototype of wind power generator experimental platform was experimentally studied. That the conclusions of the experiments accord with the simulation calculated results verifies the validity of control strategy. And the foundation of theory and experiment for practical application of MC are provided by these results.