Scientific developments

Power grids are developing rapidly to meet demands such as the significant increase in dispersed sources, intermittent operating conditions, the increasing demands for energy efficiency and power supply reliability, the integration of renewable energies in the liberalised electricity market, the controlling of electric energy demand and the power profiles consumed.

The electric energy transmission and distribution networks are concerned, but also, to varying degrees, the internal networks of industrial units and buildings, as well as the specific networks of transport systems and their on-board networks. The development towards Smart Grids aims to « optimally » fulfil the aforementioned, and sometimes contradictory, requirements.

The Networks Team contributes to these objectives with its scientific developments concerning the energy supervision and architecture of electrical networks of any type (land-based, offshore, on-board, housing, railways, etc.) The major developments can be broken down as follows:

• Integration of decentralised sources and loads in the networks. The development of the value of energy storage solutions by pooling services and adapted multi-objective supervision contributes to the integration of multi-source and multi-load systems.
• Production supervision and planning in the networks: dealing with congestion, frequency and voltage adjustments, island operation, stochastic planning.
• Experimentation methodologies adapted to network issues using the Distributed Energy platform: real-time modelling of electrical networks, real-time implementation of multi-objective supervisors, terrestrial and offshore HVDC architecture, on-board HVDC networks and associated protections.

« Distributed energy » experimental technological platform

The purpose of this platform is to study the behaviour of electrical networks in the case of decentralised production. It gathers together different production, storage or charging devices: a photovoltaic power station (18 kW), a cogeneration system, super capacitors as well as static or dynamic emulation devices of various kinds.

This experimental platform is used to test and evaluate strategies for managing electrical networks, using alternating or direct voltage, by coordinating production units of energy sources of different types, storage systems and partially controllable loads. In addition, it incorporates a real-time simulator at the heart of its system. This can therefore be interfaced with real equipment using power amplifiers so as to take into account their behaviour in a real-life interaction with a network.

Examples of achievements

Development of supervision techniques for electrical systems whose status or behaviour is poorly known (random), whose time horizons to be integrated can be very short (real time to react to dynamic stresses) and long (e.g. one year in order to take into account the seasonality of renewable sources). Contribution of the storage of electrical energy (inertial storage, supercapacitor, batteries, compressed air storage) to the integration of renewable energies in an electrical network, and coupling with building, electric vehicle or rail vehicle related loads.

Management of meshed high voltage DC electrical networks used to facilitate the massive integration of offshore wind energy within onshore power grids.

A 3kW DC local network emulator for energy exchanges in aeronautics, integrating a supercapacitor storage device, is used for the experimental validation of real-time energy supervision strategies, developed within the team.

Local HVDC network for energy exchanges in aeronautics