ASSTRA is an interdisciplinary training and research project that targets the development of advanced solid state transformer technology which enables a sustainable and flexible (‘Smart’), DC-equipped energy supply system with a large share of renewable energy sources. This futuristic electrification network has in its core a flexible power conversion unit, distributing electrical energy from sources to loads in a similar fashion as today’s internet hubs distribute information from senders to receivers. Specifically, this power conversion unit integrates state-of-the-art technology, such as Silicon-Carbide, in order to implement power electronics building blocks and magnetic components featuring breaking through performances, which will ultimately enable its industrial deployment. ASSTRA involves a two-partner network comprising the Eindhoven University of Technology (TU/e) in the Netherlands and ABB Corporate Research Center in Switzerland as beneficiaries. These partners complement each other in order to cover the knowledge and expertise fields required for the proposed program. A board of 6 experienced supervisors will intensively work together across a multitude of disciplines, including power electronics engineering, mechanical engineering, software engineering, material sciences and magnetics design, to train and mentor 2 Early Stage Researchers who will have access to excellent research facilities and close coaching approaches at both locations

Our society strongly depends on critical information infrastructures such as electrical grids, autonomous vehicles, blockchain applications, IoT critical infrastructures, etc. Not only do we increasingly rely on such complex infrastructures for the correct functioning of our society, in many occasions, even our lives depend on them being safe and secure. Critical infrastructures are the target of attacks aiming at stealing critical assets such as money and data. Vulnerabilities in software components used by these infrastructures are regularly found and exploited, sometimes allowing attackers to control physical components of SCADA (Supervisory Control And Data Acquisition) systems such as the New York Dam or Ukraine's Power Grid. As we keep seeing in the news, failures of such systems can be catastrophic. The decentralized nature of some of these infrastructures require complex mechanisms to guarantee that the data they handle is safe and secure. For example, blockchain systems allow remote users to agree on and maintain a digital ledger of transactions. They rely on complex agreement algorithms to provide those guarantees and ensure the correct functioning of the systems while users interact remotely and propose transactions concurrently. Such systems can even work correctly when some users are faulty (possibly acting maliciously). As for SCADA systems, bugs are regularly found and exploited to steal critical assets in such systems. Among the agreement algorithms used in blockchain technology, traditional Byzantine Fault Tolerant (BFT) protocols require little computing power, and can be used to harden any (deterministic) service (e.g., a banking service). They achieve this by replicating the service across a number of machines such that the correctly functioning machines hide the behavior of the faulty ones. However, one drawback of such protocols is that they require two thirds of the users to be honest, and a large number of messages to be exchanged before transactions are accepted. While BFT techniques have primarily been used in blockchain systems, other infrastructures could benefit from it if it was delivering the required properties. For example, in order to use BFT protocols in SCADA systems, they would have to guarantee that operations that need to be agreed upon between multiple remote components, can be achieved in a timely manner. These issues call for (1) developing generic, yet efficient defence mechanisms that can be applied to a wide range of infrastructures, and (2) provide strong correctness guarantees. First, in this project we propose to develop efficient BFT protocols that can be applied to a wide range of infrastructures. More precisely, we propose to develop novel BFT techniques that are less costly (less replicas and less exchanged messages) than state-of-the-art solutions by relying on trusted components (e.g., secure hardware components such as Intel SGX), and to apply these techniques to develop more efficient and reliable blockchain systems. Moreover, we also propose to develop techniques to turn state-of-the-art BFT protocols into protocols that achieve timeliness guarantees, allowing their integration in real-time applications. Secondly, we propose to guarantee the correctness of these novel protocols. One way to provide strong correctness guarantees is to use formal verification methods, such as theorem provers to automatically or interactively prove that a piece of software or hardware behaves as intended. Many theorem provers have been developed and improved over the years allowing to do just that, such as Agda, Coq, Isabelle, etc. Our project will make use of the highly expressive Coq prover to ensure the correctness of these protocols. More precisely, we propose to develop within Coq, support to implement BFT protocols, models to capture the environments in which those protocols execute, as well as proof techniques to guarantee their correctness.

Ensuring system security and stability is an ever-present concern in power system engineering due to the crucial importance of reliable power supply in modern society. The growth of renewable energy increases the number of power electronic converters present in the power network since they are needed to interface non-conventional forms of generation to standard 50 or 60 Hz system. This changes the network's physical structure and causes new threats to security. Compared to conventional power equipment, power electronic converters are subject to rigid capacity constraints which make them prone to lose functionalities during large disturbances and trigger fault cascading. On the other hand, converters have higher flexibility and faster response which enable more versatile patterns of dynamic control. Therefore, a new methodology for both converter design and system operation is needed to take advantage of the strengths and mitigate the weaknesses of converters in supporting grid security. This problem is difficult because power electronic converters have sophisticated internal dynamics which further interact with a complex power network with a vast number of nodes and uncertain disturbance scenarios. What adds to the difficulty is that converters and networks are created by very different owners and supply chains that newly come together but still have different perspectives and technical languages. This fellowship aims to establish a common technology framework for converter manufacturers and network operators, and find a systematic methodology and practical tools for grid-supportive converter design and converter-based grid security management. The proposed research sets out to do three things. First, it will find analytical methods to quantify the support provided by and stress placed on converters regarding network security, from which converter design guidelines will be derived to optimize the security support functions in a cost-effective way. Second, it will build computational platforms for network operators to use a vast number of converters synergistically for real-time security management. Third, it will develop proof-of-concept prototypes, demonstrate their application potential in a complex power system, and promote commercialization and standardization.

Ensuring system security and stability is an ever-present concern in power system engineering due to the crucial importance of reliable power supply in modern society. The growth of renewable energy increases the number of power electronic converters present in the power network since they are needed to interface non-conventional forms of generation to standard 50 or 60 Hz system. This changes the network's physical structure and causes new threats to security. Compared to conventional power equipment, power electronic converters are subject to rigid capacity constraints which make them prone to lose functionalities during large disturbances and trigger fault cascading. On the other hand, converters have higher flexibility and faster response which enable more versatile patterns of dynamic control. Therefore, a new methodology for both converter design and system operation is needed to take advantage of the strengths and mitigate the weaknesses of converters in supporting grid security. This problem is difficult because power electronic converters have sophisticated internal dynamics which further interact with a complex power network with a vast number of nodes and uncertain disturbance scenarios. What adds to the difficulty is that converters and networks are created by very different owners and supply chains that newly come together but still have different perspectives and technical languages. This fellowship aims to establish a common technology framework for converter manufacturers and network operators, and find a systematic methodology and practical tools for grid-supportive converter design and converter-based grid security management. The proposed research sets out to do three things. First, it will find analytical methods to quantify the support provided by and stress placed on converters regarding network security, from which converter design guidelines will be derived to optimize the security support functions in a cost-effective way. Second, it will build computational platforms for network operators to use a vast number of converters synergistically for real-time security management. Third, it will develop proof-of-concept prototypes, demonstrate their application potential in a complex power system, and promote commercialization and standardization.