FPGA-based Measurement Instrument for Power Quality Monitoring according to IEC Standards

Nowadays, large scale monitoring of Power Quality (PQ) in electrical power plants is a pressing need in many countries due to the liberalization of the electrical market and the deeper interconnections of electrical networks. Many instruments are available on the market but their cost make them not suited for the purpose. To overcome this problem the paper proposes a prototypal measurement instrument for PQ monitoring based on field programmable gate arrays, in compliance with IEC 61000-4-30 and IEC 61000-4-7 standards. Features of the proposing instrument are the good accuracy and the cost effectiveness. The realized instrument applies a novel digital filter approach to harmonic and interharmonic estimation. After a detailed description of the proposed instrument, an experimental performance characterization in emulated environment is presented. Results are also compared with those furnished by a FFT approach suggested by IEC61000-4-7 standard confirming the goodness of the proposal.