Areas of expertise
Energy consumption is constantly increasing all around the world. In light of this reality, GRÉPCI is seeking to improve and optimize the technology used by existing systems for the purpose of integrating renewable energy.
Digital control and simulation of electric drives
This area of research covers the application of modern control principles to torque and speed control or the control of electric drive positions. Electric motors and electronic converters, which are the main components of electric drives, constitute multi-variable non-linear systems with parameters that vary over time. These types of systems present significant challenges in terms of control. Exceptional performance (rapid dynamics, robustness, precision, etc.) can only be produced using modern control techniques, such as non-linear, adaptive and robust control. The electric drives that we study include primarily those based on permanent magnet synchronous motors, asynchronous motors and variable reluctance motors. Particular attention is paid to closed-loop speed control with no encoder based on various types of observers. Our team has also developed a library of electric drive simulation models for Matlab/Simulink.
Supervising professors : Louis-A. Dessaint and Ouassima Akhrif
Advanced aeronautic systems and robotic controls
This area focuses on the dynamic modelling and control of aircraft and robots. In terms of aircraft, active flight control is a concept that was recently introduced to civil aviation and is made possible by “Fly-By-Wire” technology. This type of control is being developed for longitudinal and lateral aircraft models. There is also a significant amount of interest in controller gains optimization and stacking, along with fault control, and more specifically, fault identification, fault tolerant control and control reconfiguration. Non-linear control of helicopters is another area of interest.
In the case of mechatronic systems, we study manipulator robots and mobile robots, with a particular focus on non-linear and adaptive controls. Highlights within this field of research include parameter estimation methods, stability analysis, hybrid control of robots (position/force), cooperation among robots and real-time implementation. We also examine exoskeleton robots, focusing primarily on the rehabilitation component.
Supervising professors: Ouassima Akhrif and Maarouf Saad
Coordinated voltage control of power transmission networks
The level of demand on electric grids is constantly growing, and these networks sometimes operate under unexpected conditions, causing instability and increasing the risk of breakdowns. Alternators and compensators are the only components that allow for regulated voltage transmission points within networks in order to handle load and topological variations, not only locally and regionally, but also globally. In this field, we are enhancing our expertise with a view of developing global control techniques for controlling the network voltage map by acting automatically on the production of reactive power in some groups within a zone in order to improve voltage safety on electricity transmission networks.
Supervising professors: Maarouf Saad and Pierre Jean Lagacé
Simulation of electric power networks
Over the course of the past thirty years, simulation has become one of the major tools used in planning and managing electricity transmission networks. Electricity network simulation is a very promising research area for producing new scientific and technological developments.
For more than fifteen years, GRÉPCI has been a major research partner of Hydro-Québec in the area of simulating network electromagnetic phenomena. Working in collaboration with Université Laval and the Hydro-Québec Research Institute, GRÉPCI played a key role in developing SimPowerSystems (SPS). More specifically, Professors Al-Haddad and Dessaint developed and built the Power Electronics, Converters, Electric Machines and SPS regulators libraries. Professor Dessaint and his graduate students also contributed to the development of Hypersim, Hydro-Québec’s fully digital real-time electric grid simulator. The research conducted in this area includes the development and validation of new SPS models. Professor Lagacé has been involved in the development of models using EMTP-RV.
Supervising professors: Louis-A. Dessaint and Pierre Jean Lagacé
Power electronics and electric machines
GRÉPCI’s activities in this area focus primarily on static electric energy converters using power semiconductors, concentrating on research into new structures that use the soft switch principle in order to improve the performance and supply weight-power ratio in embedded applications and in the telecommunications field.
This research area also covers the development of new harmonized mitigation techniques (active filters, shunts, series and hybrid) for improving the quality of electric power and cleaning the harmonics pollution network generated by non-linear loads (variable speed drives, power supply sources, etc.). The Group also conducts research into integrating FACTS into the electric grid in order to better control the flow of power and looping, improve load sharing and transient stability and regulate the voltage damping system and reactive power. New semiconductor components (IGBT, MCT, etc.) are also being studied for integration into new industrial applications. Finally, modelling and simulation are widely used to facilitate the design of complex converters and the identification of their control laws for various industrial applications.
Supervising professors: Kamal Al-Haddad and Ambrish Chandra
Renewable energy
Driven by climate change concerns that are largely associated with energy generation and consumption, researchers are currently investigating viable and sustainable technologies to meet the ever-increasing need for electricity to provide an acceptable quality of life for vast populations inhabiting the planet, understanding that the majority of people are still deprived of this luxury. “Green Power” is the path to developing these technologies using renewable energy sources, including wind and solar power.
The problem is exacerbated for remote and dispersed communities, for which off-grid solutions using locally available sources are appropriate. Many communities are interested in pursuing energy efficiency and renewable energy projects as a means of reducing energy costs, developing local economies and increasing local sovereignty over their energy supply while simultaneously reducing the environmental impact on their traditional lands.
In addition to off-grid applications, grid-connected renewable energy sources also represent a major challenge. Connecting hundreds and thousands of renewable energy sources to the energy distribution network introduces different dynamics to the system, and if the sources are not properly controlled, the grid can become unstable and even fail. As electric power systems move toward smart grids, it is crucial that renewable energy technologies are compatible with the grid, and vice versa. One important aspect of the smart grid is that it must seamlessly integrate many types of generation and storage systems into a simplified interconnection process. This means that renewable energy systems must change in terms of their current passive nature with respect to the grid in order to become active participants with a view to improving the quality of power.
Professor Ambrish Chandra supervises the research that is being conducted in all areas associated with renewable energies, including various kinds of wind conversion systems (DFIG, PMSG, SCIG) and photovoltaic and hybrid systems (diesel generator groups, battery storage, grid interfacing, off-grid systems, PHEVs, V2G, smart grids, etc.), DFIG and sensorless PMSG-based wind turbines have already been implemented into the hardware laboratory, and various control techniques have been tested.
Supervising professor: Ambrish Chandra