Data sampling method and system, and application method and system thereof in parameter identification

A data sampling system for converting an analog signal to a digital signal, comprising:

• an analog-to-digital converter for sampling an analog signal y of a physical quantity with a sampling frequency satisfying the Nyquist theorem to obtain a sampled sequence Y1;
• a low-pass filter for implementing digital low-pass filtering on the sampled sequence Y1 to obtain a filtered sampled sequence Y2;
• a processor configured to re-sample the filtered sampled sequence Y2 to obtain a sampled sequence Y at a re-sampling frequency frs and said frs≦fsh=ζmax/ε;
• where ε is a Z-domain error of a sampling system and ζmax is a maximum error of S-domain.

A parameter identification system comprising:

• a data sampling system for converting an analog signal to a digital signal, including:
• an analog-to-digital converter for sampling an analog signal v of a physical quantity with a sampling frequency satisfying the Nyquist theorem to obtain a sampled sequence Y1;
• a low-pass filter for implementing digital low-pass filtering on the sampled sequence Y1 to obtain a filtered sampled sequence Y2;
• a processor configured to re-sample the filtered sampled sequence Y2 to obtain a sampled sequence Y at a re-sampling frequency frs and said frs≦fsh=ζmax/ε, where ε is a Z-domain error of a sampling system and ζmax is a maximum error of S-domain, wherein the processor is configured to perform dynamic state parameter identification and static state parameter identification according to the sampled sequence Y.