High-order sliding mode control of DFIG-based marine current turbine

Abstract

This paper deals with the speed control of a variable speed DFIG-based marine current turbine. Indeed, to increase the generated power and therefore the efficiency of a marine current turbine, a nonlinear controller has been proposed. DFIG has been already considered for similar applications particularly wind turbine systems using mainly PI controllers. However, such kinds of controllers do not adequately handle some of tidal resource characteristics such as turbulence and swell effects. Indeed, these may decrease marine current turbine performances. Moreover, DFIG parameter variations should be accounted for. Therefore, a robust nonlinear control strategy, namely high-order sliding mode control, is proposed. This control strategy relies on the resource and the marine turbine models that were validated by experimental data. The sensitivity of the proposed control strategy is analyzed regarding the swell effect as it is considered as the most disturbing one for the resource model. Tidal current data from the Raz de Sein (Brittany, France) are used to run simulations of a 7.5-kW prototype over various flow regimes. Simulation results are presented and fully analyzed. Index Terms-Marine current turbine (MCT), doubly-fed induction generator (DFIG), modeling, nonlinear control, highorder sliding mode. NOMENCLATURE DFIG = Doubly-Fed Induction Generator; MCT = Marine Current Turbine; ρ = Fluid density; A = Cross-sectional area of the marine turbine; V tide = Fluid speed; C p = Power coefficient; C = Tide coefficient; V st (V nt ) = Spring (neap) tide current speed; s, (r) = Stator (rotor) index; d, q = Synchronous reference frame index; V (I) = Voltage (Current); P (Q) = Active (Reactive) power; φ = Flux; T em (T m ) = Electromagnetic torque (Mechanical torque); R = Resistance L (M) = Inductance (Mutual inductance); θ r = Rotor position; This work is supported by Brest Métropole Océane (BMO) and the European Social Fund (ESF). It is also supported by the GDR SEEDS CNRS N°2994 under the Internal Project HYDROLE. It is done within the framework of the Marine Renewable Energy Commission of the Brittany Maritime Cluster (Pôle Mer Bretagne).ω r (ω s ) = Angular speed (Synchronous speed); f = Viscosity coefficient; J = Rotor Inertia; p = Pole pair number.

2002–2012: 10 Years of Research Progress in Horizontal-Axis Marine Current Turbines

“…Ben Elghali and co-workers from France have been actively involved in research on HAMCT generator performance since 2007 [19,[103][104][105][106][107][108][109][110][111][112]. They started by developing a Matlab-Simulink model to model the marine current energy [19] and step-by-step, they validated the developed model for different generator-based HAMCTs.…”

High-order sliding mode control of a DFIG-based Wind Turbine for power maximization and grid fault tolerance

“…Up to now, a few secondorder sliding mode control approaches have been introduced for renewable energy applications [22][23][24].…”

Augmentation Channel Design for a Marine Current Turbine in a Floating Cogenerator

“…Específicamente las turbinas para corrientes marinas (MCTs) están en consideración por grupos de investigación y empresas. Proyectos como el SeaFlow (300KW) en Lynmouth en la costa norte de Devon o SeaGen (1.2MW) en Strangford Narrows, Irlanda del Norte, demuestran la viabilidad de este tipo de generación [3], [4].…”