FPGA-based solution for real-time tracking of time-varying harmonics and power disturbances

A field programmable gate array (FPGA)-based implementation scheme of the universal amplitude demodulation is proposed for real-time tracking of time-varying harmonics and power disturbances in power systems. The scheme implements the required lowpass filtering with canonical signed digit (CSD) coded infinite impulse response (IIR) filters and uses the coordinate rotation digital computer (CORDIC) algorithm for the amplitude reconstruction. The proposed scheme has low complexity and is suitable for practical implementations. An FPGA-based circuit had been built to validate the proposed scheme. The circuit can track harmonics and power disturbances in about one cycle. Experimental results show the real-time performance of the scheme.