A FPGA-based implementation of data acquisition and processing for digital protective relays

In order to improve the performance of digital protective relays, a data acquisition and processing system based on a FPGA is designed in VHDL and implemented in this paper. They are four parts to this system: ADC control, 32-point FFT module, frequency counter and power meter. It can control the ADC and multiplexer to sample and convert the 16-channel voltage and current signals of a power system, process the discrete data with FFT algorithms in real time, and measure the system frequency and power. Hence it can supply the processed data for protective relays and measurement All parts can be implemented in an Altera ACEX EP1k100. Using this system, the protective relays achieve good characteristics: high reliability and performance, multifunction, small size and low cost.