Power Components Estimation According to IEEE Standard 1459–2010 Under Wide-Range Frequency Deviations

Simple method of fundamental reactive power measurement for ASIC application

“…In the latter case, the voltage and current samples are sampled using analogue-to-digital converters (ADCs) and multiplied sample by sample to obtain the digitised instantaneous power [4], or the complex values of the voltage and current harmonics are calculated by a discrete Fourier transform (DFT), which is used for the determination of the powers in the frequency domain [5]. If the multiplication in the time domain is used, a shift of the fundamental voltage or current signal by π/2 must be performed before the multiplication operation to determine the reactive power [3,[6][7][8].…”

“…Methods based on signal low-pass filtering for fundamental power measurements overcome the intrinsic downsides of methods that are based on the Fourier transform [6], which require adjustment of algorithms if the power frequency varies, e.g. resynchronisation of the sampling frequency [5,6] or software resampling [15] and the subsequent usage of the fast Fourier transform (FFT).…”

“…Methods based on signal low-pass filtering for fundamental power measurements overcome the intrinsic downsides of methods that are based on the Fourier transform [6], which require adjustment of algorithms if the power frequency varies, e.g. resynchronisation of the sampling frequency [5,6] or software resampling [15] and the subsequent usage of the fast Fourier transform (FFT). Moreover, the re-synchronisation of the sampling frequency always take place awhile after the actual power frequency changes [16], which is hardly accurate in systems with a continuously varying frequency, like in microgrids [17,18].…”

“…The authors proposal is a compromise between the solution proposed in [6] and the methods employed by the manufacturers of microchips already on the market [7,8]. In [6], adaptive low-pass finite impulse response (FIR) filters that are preceded by decimation filters were proposed for determining the power components defined in IEEE standard 1459-2010 [3]. To obtain fundamental reactive power, an adaptive phase shifter was implemented for the extracted fundamental component of the voltage.…”

“…The FIR filters and shifter were adapted to accommodate the frequency changes, which are determined by fundamental frequency estimation module. Moreover, to eliminate the side effects of the chosen filters, a correction factor for the fundamental frequency was applied [6]. The algorithm can be used for precise measurements, but is more demanding for the hardware than the above-mentioned solutions already on the market [7,8].…”