Coordinateurs du projet
Context
The control of a wind turbine is developed taking into account grid parameters and the interaction of the wind system with the grid. The main variables controlled are the speed of the machine and the active and reactive power exchanged with the grid. The control system is based on the use of a control model that takes into account the electrical system to which the machine is connected. In this way, in addition to local objectives (i.e., those related to the machine, such as monitoring voltage and speed setpoints), grid services—such as voltage and frequency support or damping of hyposynchronous oscillations—can be provided.
In addition, the new control system based on an extended control model (machine + grid) will be able to monitor real-time changes in the grid through direct parameterization. The machine-grid coupling will be validated both in simulation and on a hardware-in-the-loop benchmark.
Scientific breakthroughs and innovation
The COMEOL project at Centrale Nantes straddles two disciplines: automation—for the synthesis of control laws—and electrical engineering/electronics for the network and machine/power electronics aspects.
The connection of the machine to the network is taken into account in the synthesis of the control law in order to guarantee a priori performance and verify it through a posteriori simulations (i.e., after proposing a control law). The control model envisaged directly captures the characteristics of the network to which the machine will be connected. In addition to direct consideration, this also allows the control to be adapted to variations in the structure and operating point of the network. To meet these requirements, an innovative control approach is envisaged, which is very different in its design and final form from the classic vector control approach.
Expected technical and economic impact
This project aims to improve the service provided by offshore wind farms to the electricity transmission grid (frequency, voltage, reactive power requirements, etc.) by developing innovative wind turbine control systems that can adapt in real time to changes in both grid requirements and offshore wind farm production.
The companies partnering in this project will gain a better understanding of the issues involved in connecting wind generators to the electricity grid. They will be able to make better decisions in their future projects and use these innovative control systems in their future technological developments.
Results
This project focuses on the robust control of a permanent magnet synchronous generator (PMSG) connected to a grid.
The first contribution of the project is the modeling of a wind energy conversion system based on a permanent magnet machine—Permanent Synchronous Generator (PMSG)—connected to the electrical grid by two back-to-back converters. The advanced robust control depends on an analytical model of the complete system (and not just an interconnection of predefined blocks in a simulation tool such as Simulink/Simscape). This model has been constructed and validated. The control was synthesized from this model and then tested in MATLAB simulation.
The second contribution of the project concerns a new control method for the proposed model.
It is a robust control with full state feedback of the system. It has the particularity of directly taking into account (in an analytical manner) the short-circuit power of the grid to which the generator is connected. This provides robustness with respect to variations in the operating point of the grid and better rejection of disturbances (such as short circuits and voltage dips). This allows the generator to remain connected to the grid during these disturbances and, as a result, to better participate in system services.