The FDA Guide suggests that the sampling scheme and duration should be the same as for phase one.
FDA指南建议取样计划和持续时间和第一阶段一样。
2
Anew approach, named Modified Fast Fourier Transform (MFFT), is proposed to analyze the components of a periodic signal when samplingduration is not equal to an integer multiple of the fundamentals.
When fault duration is longer than phase difference will result in fault sampling by two registers and make feedback circuit in fault state for a long time.