Linux- and FPGA-based accelerated single-phase shunt active power filter

Abstract

This paper focuses on the challenges faced when developing modern power electronic converters towards the concept of tomorrow's smart grids. Industrial and commercial electronic devices are nonlinear loads by nature and so they absorb non-sinusoidal currents and usually a chump of reactive energy. The presence of such loads raises power quality problems at installation sites as well as in the distribution system. Research has been focused on the electronic converters to improve electrical waveform quality, in particular, on shunt active power filters which are suitable to compensate current harmonics. In this paper, a shunt active power filter with an integrated Hardware/Software Digital Controller based on the p-q Power Theory is presented. A state-of-the-art embedded digital controller was deployed on Linux leveraging design re-use, implementation portability, scalability as well as designer flexibility. To tackle the performance limitations, to increase system determinism and the overall latency time of the controller, the operating system overhead was minimized by (1) offloading critical software components of the controller to FPGA, (2) minimizing user- and kernel-space memory crossings to a minimum, and (3) exploring FPGA-based platforms and their communication interfaces, to promote high speed control and communication concurrency.