A process for providing positive primary control power by wind turbines

European Workshop on Advanced Control and Diagnosis

Marschner, V.^1 ; Michael, J.^2 ; Liersch, J.^2

Technische Universität Berlin, Straße des 17. Juni 135, Berlin

10623, Germany^1

Key Wind Energy GmbH, Cicerostraße 37, Berlin

10709, Germany^2

关键词: Aerodynamic efficiency;    Control process;    Electricity generation;    Grid integration;    Rotating flywheels;    Rotational energy;    Rotational speed;    Simple Physical Models;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/570/5/052002/pdf
DOI  :  10.1088/1742-6596/570/5/052002

来源: IOP

【 摘 要 】

Due to the increasing share of wind energy in electricity generation, wind turbines have to fulfil additional requirements in the context of grid integration. The paper examines to which extent wind turbines can provide positive control power following the related grid code. The additional power has to be obtained from the rotating flywheel mass of the wind turbine's rotor. A simple physical model is developed that allows to draw conclusions about appropriate concepts by means of a dynamic simulation of the variables rotational speed, torque, power output and rotor power. The paper discusses scenarios to provide control power. The supply of control power at partial load is examined in detail using simulations. Under partial load conditions control power can be fed into the grid for a short time. Thereby the rotational speed drops so that aerodynamic efficiency decreases and feed-in power is below the initial value after the control process. In this way an unfavourable situation for the grid control is produced, therefore the paper proposes a modified partial load condition with a higher rotational speed. By providing primary control power the rotor is delayed to the optimum rotational speed so that more rotational energy can be fed in and fed-in power can be increased persistently. However, as the rotor does not operate at optimum speed, a small amount of the energy yield is lost. Finally, the paper shows that a wind farm can combine these two concepts: A part of the wind turbines work under modified partial load conditions can compensate the decrease of power of the wind turbines working under partial load conditions. Therefore the requested control power is provided and afterwards the original value of power is maintained.