一种新型离散域数字化并网同步方法研究

A NOVEL DISCRETE DOMAIN DIGITAL SYNCHRONIZATION METHOD

由于实际电网电压存在各种非理想情况,电网电压中的不平衡、谐波、直流分量等非理想因素将会并网同步产生负面影响,造成并网同步误差。为了解决该问题,提出一种新型数字化离散域并网同步方法,建立新型同步方法的数学模型,并对系统特性和系统参数进行分析和设计。与传统连续域方法相比,提出的方法直接数字实现,无需连续域到离散域的转换过程,而且可快速准确地提取出基波电压正序和负序同步信号。最后通过仿真和TMS320F2812 DSP硬件平台实验验证所提方法的有效性。

Grid synchronization and phase-locked loop are the key parts for operating the grid-connected power converters,which have been widely used. In practice,the grid voltage may be non-ideal. The unbalance,harmonics and DC components in the grid voltage will result in the negative side,which leads to the grid synchronization error. In order to solve the problem,a new digital discrete-domain grid synchronization method is proposed in this paper. The mathematic model is built,and system characteristics and parameters are analyzed and designed. Compared with the conventional continuous-domain method,the proposed digital method can be implemented directly,with no need of transferring the continuous-domain to discrete-domain procedure. Moreover,the fast and accurate extraction of the positive and negative sequence signals can be achieved. Finally,the simulation and experimental tests on the hardware platform are carried out to verify the effectiveness of the proposed method.