Non-ideal torque control of wind turbine systems: Impacts on annual energy production

TL;DR

This paper examines how non-ideal torque control in wind turbine systems, due to sensor limitations and parameter uncertainties, affects annual energy output and economic returns, using real data and dynamic modeling.

Contribution

It provides an analysis of the causes and impacts of non-ideal torque control on wind turbine energy production and profitability.

Findings

Non-ideal torque control reduces energy output.

Parameter uncertainties significantly affect control accuracy.

Impacts on gross earnings are substantial.

Abstract

We discuss non-ideal torque control in wind turbine systems (WTS). Most high-level controllers generate a reference torque which is then send to the underlying electrical drive system (generator+inverter) of the WTS to steer the turbine/generator to its optimal operation point (depending on the wind speed). The energy production heavily depends on the mechanical power (i.e. the product of rotational speed and generator torque). However, since torque sensors in the MW range are not available or extremely expensive, the torque controllers are implemented as feedforward controllers and, therefore, are inherently sensitive to parameter variations/uncertainties. Based on real wind data and a dynamical WTS model, we discuss causes and impacts of non-ideal (feedforward) torque control on the energy production and the gross earnings.