Picture of person typing on laptop with programming code visible on the laptop screen

World class computing and information science research at Strathclyde...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including by researchers from the Department of Computer & Information Sciences involved in mathematically structured programming, similarity and metric search, computer security, software systems, combinatronics and digital health.

The Department also includes the iSchool Research Group, which performs leading research into socio-technical phenomena and topics such as information retrieval and information seeking behaviour.

Explore

Choice and properties of adaptive and tunable digital boxcar (moving average) filters for power systems and other signal processing applications

Roscoe, Andrew J. and Blair, Steven M. (2016) Choice and properties of adaptive and tunable digital boxcar (moving average) filters for power systems and other signal processing applications. In: IEEE Applied Measurements for Power Systems (AMPS 2016), 2016-09-28 - 2016-09-30, E.On Energy Research Center, RWTH Aachen University.

[img]
Preview
Text (Roscoe-Blair-AMPS2016-Choice-and-properties-of-adaptive-and-tunable-digital-boxcar-filters)
Roscoe_Blair_AMPS2016_Choice_and_properties_of_adaptive_and_tunable_digital_boxcar_filters.pdf - Accepted Author Manuscript

Download (525kB) | Preview

Abstract

The humble boxcar (or moving average) filter has many uses, perhaps the most well-known being the Dirichlet kernel inside a short-time discrete Fourier transform. A particularly useful feature of the boxcar filter is the ease of placement of (and tuning of) regular filter zeros, simply by defining (and varying) the time length of the boxcar window. This is of particular use within power system measurements to eliminate harmonics, inter-harmonics and image components from Fourier, Park and Clarke transforms, and other measurements related to power flow, power quality, protection, and converter control. However, implementation of the filter in real-time requires care, to minimise the execution time, provide the best frequency-domain response, know (exactly) the group delay, and avoid cumulative numerical precision errors over long periods. This paper reviews the basic properties of the boxcar filter, and explores different digital implementations, which have subtle differences in performance and computational intensity. It is shown that generally, an algorithm using trapezoidal integration and interpolation has the most desirable characteristics.