Time-domain Continuous FIR Filter Based Electronic Instrument Transducers Sampling Data Inter-substation Synchronization Arithmetic

Under electronic instrument transducer applica-tion circumstance,sampling data synchronization between substaions should be achieved as sampling clocks of substations keep independent.This paper presents the concept of time-domain continuous finite impulse response(TCFIR)filter to solve this problem.A TCFIR based continuous digital low pass filter was constructed to acquire continuous signal from EPT/ECT discrete output data and calculate sampling value at any moment.Simulation and time-frequency domain analysis using 500kV transmission line fault current with strong harmonic was carried out.With 1000Hz,2400Hz and 4000Hz sampling frequency,the RMS and DFT fundamental amplitude error is less than 0.4%.Meanwhile,the arithmetic data window length is 6 points and the time delay is only 3 sampling intervals.The result shows that the arithmatic meets the accuracy and realtime requirement of protection and distributed stability control application.