On the Importance of Characterizing Virtual PMUs for Hardware-in-the-Loop and Digital Twin Applications

Abstract

In recent years, the introduction of real-time simulators (RTS) has changed the way of researching the power network. In particular, researchers and system operators (SOs) are now capable of simulating the complete network and of making it interact with the real world thanks to the hardware-in-the-loop (HIL) and digital twin (DT) concepts. Such tools create infinite scenarios in which the network can be tested and virtually monitored to, for example, predict and avoid faults or energy shortages. Furthermore, the real-time monitoring of the network allows estimating the status of the electrical assets and consequently undertake their predictive maintenance. The success of the HIL and DT application relies on the fact that the simulated network elements (cables, generation, accessories, converters, etc.) are correctly modeled and characterized. This is particularly true if the RTS acquisition capabilities are used to enable the HIL and the DT. To this purpose, this work aims at emphasizing the role of a preliminary characterization of the virtual elements inside the RTS system, experimentally verifying how the overall performance is significantly affected by them. To this purpose, a virtual phasor measurement unit (PMU) is tested and characterized to understand its uncertainty contribution. To achieve that, firstly, the characterization of a virtual PMU calibrator is described. Afterward, the virtual PMU calibration is performed, and the results clearly highlight its key role in the overall uncertainty. It is then possible to conclude that the characterization of the virtual elements, or models, inside RTS systems (omitted most of the time) is fundamental to avoid wrong results. The same concepts can be extended to all those fields that exploit HIL and DT capabilities.

A Low-Cost Test Platform for Performance Analysis of Phasor Measurement Units

“…It should be pointed out that in [3,17,40], authors use an emulated GPS signal for low-cost PMU testing purposes. However, more realistic test platforms are necessary for research and validation of new algorithms as well as for comparison of various algorithms used to determine syncrophasors [24,25,[41][42][43][44][45]. Moreover, a custom-made test platform should have the possibility of performing additional test case studies for the purpose of academic research, which usually goes beyond what is possible with commercially available PMU calibrators.…”

The Kopernikus ENSURE Co-Demonstration Platform

“…This is especially true in the area of grids because of the size of the system, the small-scale ownership structures, and regulatory framework conditions. Many approaches of digital twins like [2]- [6] are based on real-time systems. These approaches pursue the goal of developing a digital twin for a specific application, or the digital twin itself is a component of the application in question.…”