A M Kulkarni
Articles written in Sadhana
Volume 33 Issue 5 October 2008 pp 643-661
This paper presents the implementation of Static Synchronous Series Compensator (SSSC) controller on Real Time Application Interface (RTAI) for Linux Operating System (OS). RTAI provides real-time capability to Linux General Purpose Operating System (GPOS) over and above the capabilities of non real-time Linux environment, e.g. access to TCP/IP, graphical display and windowing systems, ﬁle and database systems. Both Type II controllers, DC voltage and current scheduling controllers, are implemented in RTAI. To create a user friendly environment, Graphical User Interface (GUI) is developed in Linux OS in user space (non real-time) using a software available from Quasar Technologies (Qt). The controller is tested on a small scale laboratory model of a Voltage Source Converter(VSC) connected in series with a transmission line. The real time controller performs well in both inductive and capacitive regions.
Volume 40 Issue 1 February 2015 pp 89-106 Electrical and Computer Sciences
A Waveform Relaxation (WR) based iterative real-time playback scheme for controller testing was recently proposed in the literature along with proof-ofconcept simulations. This scheme can be a low-cost alternative to Hardware-in-Loop simulation, as it does not require a real-time simulator. To demonstrate practical feasibility of the WR scheme, this paper presents results of experiments with real-time implementation of controllers, iteratively interacting with simulated models of power apparatus via storage and real-time play-back. Two systems are considered: a HVDC controller tested with a detailed model of the converters, and a TCSC based damping controller tested with a low frequency model of a power system. The results are validated with those obtained using simulated models of the controllers. We also present results of an experiment in which the tested HVDC controller is used to control the scaled real-life HVDC apparatus, for which a simulated model was used during controller testing. Convergence and a good match between simulated and real-time implementation are obtained for the HVDC system. The experiments on the TCSC damping controller drawn our attention to a potential convergence problem which may arise due to iteration-dependent round-off noise.