An FPGA-Based Instrument for the Estimation of R, L, and C Parameters Under Nonsinusoidal Conditions

It is well known that most of today's electric and electronic devices frequently work with nonsinusoidal waveforms; then, all the passive R, L, and C components sited in these circuits are involved with nonsinusoidal stimuli. Because of their intrinsic nonlinearity, real resistors, inductors, capacitors, and so on show behaviors that are very different from those expected in a sinusoidal environment. Consequently, a problem of reliable assessment of these components in the presence of nonsinusoidal environments arises. This problem is even more critical in applications such as the creation of hybrid filters, control circuits based on patterns of sensing elements, and circuits of digital protection in power systems, where the design and control of electrical and electronic circuits depend on the correct modeling of the R, L, and C components. In previous research works, the authors proposed a suitable measurement method for the estimation of R, L, and C parameters of passive components in nonsinusoidal conditions. This paper deals with the realization of a measurement instrument, based on a Field Gate Programmable Array, that is able to continuously update the estimated values of the considered components. The instrument realization passes through an optimized implementation of the previously proposed measurement method aimed at minimizing the hardware resources and the computational burden and increasing the measurement rate. After a preliminary tuning of the measurement method, carried out in a simulation environment, the hardware and the software architectures of the realized measurement instrument, together with the measurement strategy, are described and experimentally characterized.