Publications by Wajeb Saab | EPFL Graph Search

Reliable and Robust Cyber-Physical Systems for Real-Time Control of Electric Grids

Real-time control of electric grids is a novel approach to handling the increasing penetration of distributed and volatile energy generation brought about by renewables. Such control occurs in cyber-physical systems (CPSs), in which software agents maintai ...

EPFL2019

Ordering Events Based on Intentionality in Cyber-Physical Systems

Jean-Yves Le Boudec, Simon Bliudze, Maaz Mashood Mohiuddin, Wajeb Saab

We consider cyber-physical systems (CPSs) comprising a central controller that might be replicated for high-reliability, and one or more process agents. The controller receives measurements from process agents, causing it to compute and issue setpoints tha ...

2018

T-RECS: A Virtual Commissioning Tool for Software-Based Control of Electric Grids – Design, Validation, and Operation

Jean-Yves Le Boudec, Lorenzo Enrique Reyes Chamorro, Maaz Mashood Mohiuddin, Wajeb Saab, Roman Rudnik, Jagdish Prasad Achara

In real-time control of electric grids using multiple software agents, the control performance depends on (1) the proper functioning of the software agents, i.e., absence of software faults, and (2) the behavior of software agents in the presence of non-id ...

ACM2018

Robust Real-Time Control of Power Grids in the Presence of Communication Network Non-Idealities

Jean-Yves Le Boudec, Mario Paolone, Lorenzo Enrique Reyes Chamorro, Wajeb Saab, Roman Rudnik

Deploying a power grid controller in the field makes it susceptible to message losses caused by the inherent uncertainties and non-idealities of communication networks, especially when the control action is taken at a sub-second time-scale. We consider a c ...

2018

Axo: Detection and Recovery for Delay and Crash Faults in Real-Time Control Systems

Jean-Yves Le Boudec, Simon Bliudze, Wajeb Saab

Real-time control systems use controllers that compute and issue setpoints within stringent delay constraints. Failure to do so, due to a crash or delay as a result of software and/or hardware faults, can cause failure of the controlled resources. Recently ...

2018

Experimental Validation of the Suitability of Virtualization-Based Replication for Fault Tolerance in Real-Time Control of Electric Grids

Jean-Yves Le Boudec, Maaz Mashood Mohiuddin, Wajeb Saab, Jalal Mostafa, Seyed Alireza Sanaee Kohroudi

Real-time control systems (RTCSs) perform complex control and require low response times. They typically use third-party software libraries and are deployed on generic hardware, which suffer from delay faults that can cause serious damage. To improve avail ...

2018

Slack Selection for Unintentional Islanding: Practical Validation in a Benchmark Microgrid

Jean-Yves Le Boudec, Mario Paolone, Lorenzo Enrique Reyes Chamorro, Wajeb Saab, Andreas Martin Kettner, Roman Rudnik

Upon an intentional or emergency disconnection from the main grid, a microgrid is expected to continue working in islanded mode. Thus, (at least) one resource needs to act as slack and compensate for power variations to keep the power balance, and ensure t ...

2018

A controller and an agreement protocol for a real-time control system

Jean-Yves Le Boudec, Simon Bliudze, Maaz Mashood Mohiuddin, Wajeb Saab

The present invention concerns a method of generating setpoints for actuators (13) of a real-time control system. The method comprises a first controller (9): a) receiving a first set of measurements from sensors (3), the measurements being individually la ...

2018

T-RECS: A Software Testbed for Multi-Agent Real-Time Control of Electric Grids

Jean-Yves Le Boudec, Maaz Mashood Mohiuddin, Wajeb Saab, Roman Rudnik, Jagdish Prasad Achara

Multiple software agents can be used to perform the real-time control of electrical grids. The control performance of such solutions is influenced by software non-idealities such as crashes and delays of the software agents, and message losses and delays d ...

2017

Quarts: Quick Agreement for Real-Time Control Systems

Jean-Yves Le Boudec, Simon Bliudze, Wajeb Saab

Real-time control systems (RTCSs) tolerate delay and crash faults by replicating the controller. Each replica computes and issues setpoints to actuators over a network that might drop or delay messages. Hence, the actuators might receive an inconsistent se ...

2017

Ordering Events Based on Intentionality in Cyber-Physical Systems

Jean-Yves Le Boudec, Simon Bliudze, Maaz Mashood Mohiuddin, Wajeb Saab

We consider cyber-physical systems (CPSs) comprising a central controller that might be replicated for high-reliability, and one or more process agents. The controller receives measurements from process agents, causing it to compute and issue setpoints tha ...

2017

Axo: Masking Delay Faults in Real-Time Control Systems

Jean-Yves Le Boudec, Simon Bliudze, Maaz Mashood Mohiuddin, Wajeb Saab

We consider real-time control systems that consist of a controller that computes and sends setpoints to be implemented in physical processes through process agents. We focus on systems that use commercial off-the-shelf hardware and software components. Set ...

2016

Axo: Tolerating Delay Faults in Real-Time Systems

Jean-Yves Le Boudec, Simon Bliudze, Maaz Mashood Mohiuddin, Wajeb Saab

We address delay faults: faults that cause a software component to take more time for completing an action than a given deadline. Such faults are particularly of interest in real- time mission-critical control applications that use general-purpose computin ...

2016

Aggregation of Power Capabilities of Heterogeneous Resources for Real-Time Control of Power Grids

Jean-Yves Le Boudec, Mario Paolone, Lorenzo Enrique Reyes Chamorro, Andrey Bernstein, Wajeb Saab

Aggregation of electric resources is a fundamental function for the operation of power grids at different time scales. In the context of a recently proposed framework for the real-time control of microgrids with explicit power setpoints, we define and form ...

Università degli Studi di Genova, Italy2016

Formal verification of infinite-state BIP models

Simon Bliudze, Wajeb Saab

We propose two expressive and complementary techniques for the verification of safety properties of infinite-state BIP models. Both our techniques deal with the full BIP specification, while the existing approaches impose con- siderable restrictions: they ...

Springer2015