Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller

The Science of Making Torque from Wind

Senanayaka, Jagath Sri Lal^1 ; Karimi, Hamid Reza^2 ; Robbersmyr, Kjell G.^1

Department of Engineering Sciences, University of Agder, Grimstad

4879, Norway^1

Department of Mechanical Engineering, Politecnico di Milano, Milan

20156, Italy^2

关键词: Control objectives;    Direct torque control;    Electrical machine;    Flux controllers;    Maximum Power Point Tracking;    Permanent magnet synchronous generator;    Small wind turbine;    Wind speed sensor;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/753/5/052031/pdf
DOI  :  10.1088/1742-6596/753/5/052031

来源: IOP

【 摘 要 】

In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion of the converter that gives fast responses with low overshoots. The main control objectives of the proposed small wind turbine can be maximum power point tracking and soft-stall power control. This small wind turbine consists of permanent magnet synchronous generator and external wind speed. and rotor speed measurements are not required for the system. However. a sensor is needed to detect the rated wind speed overpass events to activate proper speed references for the wind turbine. Based on the low-cost design requirement of small wind turbines. an available wind speed sensor can be modified. or a new sensor can be designed to get the required measurement. The simulation results will be provided to illustrate the excellent performance of the closed-loop control system in entire wind speed range (4-25 m/s).