【摘要】 首先简要分析了频谱泄漏的成因和其对频率分析中DFT算法的影响。在理想同步采样的条件下,提出了一种基于简谐信号复幅度的频率偏差求取算法。再依据实际采样和电网信号的特点,修正了该算法,并得出了电网频率实时检测的迭代公式。仿真结果表明,该算法在非同步采样条件下能精确、快速地跟踪频率变化,且运算量小、收敛性好、抗谐波干扰能力强,在以交流电信号实时检测为基础的系统中有较强的应用价值。更多还原

【Abstract】 First, the reason for spectrum leakage and its influence to DFT used in frequency analysis is introduced. Based on the complex magnitude of harmonic signals and under the condition of ideal synchronous samplings, an algorithm for computing the frequency deviation is proposed. Second, this algorithm is further modified according to actual sampling and the power network signals. Finally, the iterative formulas for real-time determination of power network frequency are presented as well. Simulation results show that the algorithm can follow up the frequency deviation accurately and quickly. Moreover, the algorithm will be of potential applications in the fields of AC real-time determination due to its features of less computation time, fast convergence and ability of against harmonic interference.更多还原