DIGITAL SIGNAL PROCESSING METHOD AND SYSTEM, ELECTRIC POWER SYSTEM SIGNAL PROCESSING SYSTEM AND ELECTRIC POWER CONTROL SYSTEM

摘要

A method of and system for processing a digital signal are disclosed. Disclosed also are an electric power system digital controlling system and a digital relay system which utilize the signal processing system for obtaining physical quantities of a voltage and a current inputted from the electric power system. An analog signal is sample-held. The sample-held data is converted into digital data which is then filtering-processed. Arithmetic processing is effected based on the data from a digital filter means. In this digital filter means, a blocking zone of the digital filter is set to a higher frequency zone than a passage zone of the analog signal. A sampling frequency is set so that a noise generating region is larger than the blocking zone. The synthesis noises are thereby caused in the blocking zone. IMAGE