Abstract-We describe the real-time monitoring infrastructure of the smart-grid pilot on the EPFL campus. We experimentally validate the concept of a real-time state-estimation for a 20 kV active distribution network. We designed and put into operation the whole infrastructure composed by the following main elements: (1) dedicated PMUs connected on the medium-voltage side of the network secondary substations by means of specific current/voltage transducers; (2) a dedicated communication network engineered to support stringent time limits and (3) an innovative state estimation process for real-time monitoring that incorporates phasor-data concentration and state estimation processes. Special care was taken to make the whole chain resilient to cyber-attacks, equipment failures and power outages. The achieved latency is within 65ms. The refresh rate of the estimated state is 20ms. The real-time visualization of the state estimator output is made publicly available, as well as the historical data (PMU measurements and estimated states). To the best of our knowledge, the work presented here is the first operational system that provides low-latency real-time stateestimation by using PMU measurements of a real active distribution network.

Abstract-The evolution toward emerging active distribution networks (ADNs) can be realized via a real-time state estimation (RTSE) application facilitated by the use of phasor measurement units (PMUs). A critical challenge in deploying PMU-based RTSE applications at large scale is the lack of a scalable and flexible communication infrastructure for the timely (i.e., sub-second) delivery of the high volume of synchronized and continuous synchrophasor measurements. We address this challenge by introducing a communication platform called C-DAX based on the information-centric networking (ICN) concept. With a topicbased publish-subscribe engine that decouples data producers and consumers in time and space, C-DAX enables efficient synchrophasor measurement delivery, as well as flexible and scalable (re)configuration of PMU data communication for seamless full observability of power conditions in complex and dynamic scenarios. Based on the derived set of requirements for supporting PMU-based RTSE in ADNs, we design the ICN-based C-DAX communication platform, together with a joint optimized physical network resource provisioning strategy, in order to enable the agile PMU data communications in near real-time. In this paper, C-DAX is validated via a field trial implementation deployed over a sample feeder in a real-distribution network; it is also evaluated through simulation-based experiments using a large set of real medium voltage grid topologies currently operating live in The Netherlands. This is the first work that applies emerging communication paradigms, such as ICN, to smart grids while

In this paper, the performance limits of faults localization are investigated using synchrophasor data. The focus is on a non-trivial operating regime where the number of Phasor Measurement Unit (PMU) sensors available is insufficient to have full observability of the grid state. Proposed analysis uses the Kullback Leibler (KL) divergence between different fault location hypotheses, which are associated with the observation model. This analysis shows that the most likely locations are concentrated in clusters of buses more tightly connected to the actual fault site akin to graph communities. Consequently, a PMU placement strategy is derived that achieves a near-optimal resolution for localizing faults for a given number of sensors. The problem is also analyzed from the perspective of sampling a graph signal, and how the placement of the PMUs i.e. the spatial sampling pattern and the topological characteristic of the grid affect the ability to successfully localize faults is studied. To highlight the superior performance of presented fault localization and placement algorithms, the proposed strategy is applied to a modified IEEE 34, IEEE-123 bus test cases and to data from a real distribution grid. Additionally, the detection of cyberphysical attacks is also examined where PMU data and relevant Supervisory Control and Data Acquisition (SCADA) network traffic information are compared to determine if a network breach has affected the integrity of the system information and/or operations [2].

Active power distribution networks require sophisticated monitoring and control strategies for efficient energy management and automatic adaptive reconfiguration of the power infrastructure. Such requirements are realised by deploying a large number of various electronic automation and communication field devices, such as Phasor Measurement Units (PMUs) or Intelligent Electronic Devices (IEDs), and a reliable two-way communication infrastructure that facilitates transfer of sensor data and control signals. In this paper, we perform a detailed threat analysis in a typical active distribution network's automation system. We also propose mechanisms by which we can design a secure and reliable communication network for an active distribution network that is resilient to insider and outsider malicious attacks, natural disasters, and other unintended failure. The proposed security solution also guarantees that an attacker is not able to install a rogue field device by exploiting an emergency situation during islanding.

Abstract-Multicast is proposed as a preferred communication mechanism for many power grid applications. One of the biggest challenges for multicast in smart grid is ensuring source authentication without violating the stringent time requirement. The research community and standardization bodies have proposed several authentication mechanisms for smart grid multicast applications. In this paper, we evaluate different authentication schemes and identify the best candidates for phasor data communication in wide area monitoring systems (WAMS). We first do an extensive literature review of existing solutions and establish a short list of schemes to evaluate. Second we make an experimental comparison of the chosen schemes in an operational smart grid pilot and evaluate the performance of these schemes by using the following metrics: computation, communication and key management overheads. The best candidates we consider are two variants of ECDSA, TV-HORS and three variants of Incompletekey-set. We find ECDSA without pre-computed tokens and all the Incomplete-key-set variants are inapplicable for WAMS due to their high computation overhead. The ECDSA variant that uses pre-computed tokens and TV-HORS perform well in all metrics; however, TV-HORS has potential drawbacks due to a large key management overhead as a result of the frequent distribution of a large public key per source.