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This paper exploits the availability of frequency disturbance recorder (FDR) measurements and knowledge of the underlying operational data from the Nigerian National Power System to develop a model capable of reproducing the most important characteristics of one of the many collapses in the Nigerian grid during the last recent years. The collapse investigated in this paper was captured on December 2nd , 2006, with an FDR unit installed at Abubakar Tafawa Balewa University (ATBU). Using operational information from the National Control Center (NCC) at Osogbo, three models representing the Nigerian power system were developed to capture the most relevant dynamics of the grid during the cascading failure. These models include both detailed representations of the different network components, as well as average frequency dynamics only. Comprehensive simulation results show how the models are capable of representing the most important features of the collapse of the system, and hence, their continuous improvement through model validation may allow their use in the development of load shedding mechanisms which are needed for mitigating cascading failures in the Nigerian system. QC 20120207

Synchrophasor technology is relatively new to many utility companies as they plan for its introduction as part of their smart grid infrastructure investment. A first question that arises in planning for synchrophasor technology use is where should we place the phasor measurement units (PMUs)? Because synchrophasor data can be used in a variety of applications, the placement of PMUs should be driven by the intended applications, which may have varying data needs and differing PMU siting considerations. This white paper intends to provide information on and be a resource for such PMU placement issues, using recently developed PMU placement documents from various power grid operators and from applications described in technical papers. This white paper offers some guidelines for designers and users of the synchrophasor systems to decide where to place new PMUs. The paper addresses the information requirements of power system applications under all conditions (normal, alert, emergency, restorative) and across all time horizons (monitoring, protection, control, operation, planning). As many PMU placement documents are already available, the main sections of this document will be quite brief. Some expanded details on the guidelines can be found in the appendices. QC 20120210

The successful deployment of Smart Grids at the transmission level will largely depend on the development and implementation of synchronized phasor measurement data-based applications and on the continuous improvement of the information and communication infrastructures supporting them. During the last decade several phasor measurement unit (PMU) data applications, that will potentially enable Smart Transmission Grids (STGs), have been proposed. In this paper we provide an overview on two of these applications, devoted to PMU-only state estimation, and modal analysis, as well as work related to developing some supporting IT infrastructure. Rather than discussing details of applications, this paper aims to give highlights of the relevant features of these applications in the context of STGs, and outlines additional research efforts necessary for phasing in these tools into practical use. QC 20120202

QC 20120126

This paper reports on an ongoing research effort between researchers in North America and Africa on the study of the dynamics of loosely regulated and rapidly growing power systems, with focus on the Nigerian power network. A description of the implementation of Virginia Tech’s FDR (Frequency Disturbance Recorder) at Bauchi, Nigeria is provided. We discuss the nature of the frequency dynamics observed throughout multiple hours of a day in Nigeria and other power systems. To cater to the loosely regulated nature of the system frequency in Nigeria, we propose an appropriate method for signal conditioning which prepares the data for ambient analysis. Parametric and nonparametric block processing techniques are applied to prolonged frequency recordings ranging from 8 to 19 hours, and estimates of modal frequencies and damping are obtained by computing power spectrum densities and applying a mode meter algorithm to the ambient data. The estimated modes from ambient analysis are in agreement with other studies based on power system models. QC 20120203