Application of PMU measurements in Europe TSO approach and experience

Abstract

In the last few years more and more European TSOs have started to install wide area monitoring systems, in order to enhance system observability and to improve monitoring of the dynamic system behaviour. The application of new measurement and analysis tools has become a must, as systems are increasingly operated nearer to their boundaries. Switzerland has more than seven years of experience in PMU measurements. Currently there are links to phasor data concentrators of eight other European TSOs. Applications based on these measurements continuously assess the system stability of the interconnected system with respect to poorly damped interarea oscillations on the North-South and West-East system axis. This paper will demonstrate the effectiveness of wide area analysis with the help of recent recordings and their analysis.

Structured power system model reduction of non-coherent areas

“…3). This choice is of interest if one wants to design a power system stabilizer (PSS), since such a controller is dependent on a good model with V ref, 1 as input and that is exactly what the reduced model will provide.…”

“…This can most likely be attributed to the choice of exogenous input signals to the power system. Since the only input signal, V ref, 1 , primarily excites generators 1 and 2, the model reduction algorithm will automatically assign greater importance to capturing that intraarea mode. By choosing different input signals or by adding for instance a voltage reference to one of the generators 3 or 4 as an additional exogenous input signal, more importance would be assigned to capturing the intra-area mode of generator 3 and 4.…”

“…To excite the system the input signal V ref, 1 will be used and to validate the reduced model, the variables V 6 and θ 6 − θ 5 will be chosen. This is a natural choice, since these variables define the injected power into the study area from the external area and if that injected power is well modeled, the study area will behave well as a result, since the nonlinear description is used in the reduced model.…”

“…New interconnections to neighboring networks add to the size and complexity of these systems, and this expansion trend is of particular interest in Continental Europe where additional interconnections have recently been made [1]. With this trend, new challenges for planning, operations and control of large-scale power networks will appear.…”

“…However, to address the challenges described above, and specially in the case of the different regional coordinators in Continental Europe, it would be advantageous to arbitrarily set the area corresponding to the study system without any restrictions, and without the need of satisfying coherency properties. In addition to facilitating power system security assessment [25] for the situations explained above, having such reduced models could also be beneficial in the design of power plant controllers and in the coordination of system protections for system-wide phenomena such as inter-area oscillations [1].…”