Development of a power system laboratory supported by real-time systems

In this paper, features of a power system laboratory supported by real-time systems are outlined. These real-time systems are built using an open-source RTAI-Linux which not only offers a general purpose operating system features, but also has the hard real-time capabilities. On such a platform a transient waveform recorder is developed to capture the transient behaviour of a synchronous machine under various operating conditions such as voltage buildup and sudden 3-phase symmetrical short-circuit. Using the recorded transient waveforms, a synchronous machine model development task is carried out as per the IEEE Std. 115-2009 specified procedures. Employing such a model a time-domain simulation programme is run to tune the model parameters of the machine by comparing the simulation results against the recorded waveforms. It is also found that the transient waveform recorder provides a useful tool to visualize the synchronization and loss-of-synchronism transients either with the mains supply or with another machine. As an additional application, an open-loop excitation controller for a synchronous machine is developed which involved the realization of many hardware circuits such as inverse-cosine firing-circuit module, single-phase thyristor bridge-rectifier circuits and a DAC interfacing card. Such a laboratory is found to augment the classroom teaching of a power system dynamics course.