Design and implementation of a low-cost phasor measurement unit: a comprehensive review

The complexity of the contemporary electrical power systems imposes challenges in aspect of monitoring, protection and control. In order to obtain high speed of response, wide area effect and prices synchronization, the grid control functions can be benefited by the implementation of Phasor Measurement Units (PMU). The paper is aimed to make a review of the commercial implementation of Phasor Measurement Units and then open source based implementations (open architecture hardware and software). This paper focuses on standard implementations; as a consequence the concept of virtual PMU is not discussed here

Probabilistic assessment of enhanced frequency response services using real frequency time series

This paper presents a probabilistic assessment of the novel enhanced frequency response (EFR) service in the Great Britain (GB) transmission system. Real frequency measurements with one-second resolution, released by National Grid (NG) corresponding to the years 2014 and 2015, are used for the performance assessment. Initially, the frequency quality is evaluated against Security and Quality of Supply Standards (SQSS) of NG. Afterwards, battery energy storage systems (BESSs) with different power to energy ratios have been modelled and fed with the GB frequency time-series while providing two variants of EFR service. Then, a state of charge (SOC) management algorithm is implemented for comparison purposes. Finally, cumulative probability distribution functions (CDF) are created to analyse the performance of the BESS. The high utilization rates obtained for one the EFR services suggests that for the provision of EFR to be profitable for the providers, the service should refocus towards the post-fault or frequency containment region

Assessment of the critical clearing time in low rotational inertia power systems

The growing share of power electronic/converter interfaced generation is decreasing the total system rotational inertia. The reduced rotational inertia in the power system has important impact on the electro-mechanical processes, the power angle and frequency evolution time are quicker resulting in faster transient processes. Rapid response of the protection systems shall be applied, in order to clear the faults in the power systems. This paper aims to identify the roots/mechanism of critical clearing time reduction/deterioration by determining/analyzing the trajectories of the critical clearing time (CCT) in low rotational inertia power systems. In this paper, the equal area criterion (EAC) is used for analysis purposes. Theoretical and practical findings demonstrate the increase of the rotational inertia increases the CCT