Impact of the Converter Control Strategies on the Drive Train of Wind Turbine during Voltage Dips

Abstract

Abstract:The impact of converter control strategies on the drive train of wind turbines during voltage dips is investigated in this paper using a full electromechanical model. Aerodynamics and tower vibration are taken into consideration by means of a simulation program, named FAST. Detailed gearbox and electrical subsystems are represented in MATLAB. The dynamic response of electromagnetic torque and its impact on the mechanical variables are the concern in this paper and the response of electrical variables is less discussed. From the mechanical aspects, the effect of rising power recovery speed and unsymmetrical voltage dips are analyzed on the basis of the dynamic response of the high-speed shaft (HSS). A comparison of the impact on the drive train is made for two converter control strategies during small voltage dips. Through the analysis of torque, speed and tower vibration, the results indicate that both power recovery speed and the sudden torque sag have a significant impact on drive trains, and the effects depend on the different control strategies. Moreover, resonance might be excited on the drive train by an unbalanced voltage.

Research on the Fault Characteristic of Wind Turbine Generator System Considering the Spatiotemporal Distribution of the Actual Wind Speed

“…Firstly, an inverse sequence component at the frequency −ω 1 in the stator determines an inverse counter rotating magnetic field. Then the inverse sequence component produces an harmonic component in the rotor at frequency (2 − s)ω 1 (s is the slip ratio) and give rise to electromagnetic and mechanical interaction between stator and rotor, which determine the further harmonic components both on stator and rotor [10]. As a consequence of this interaction, the following stator current components ω ss and rotor current components ω sr appear:…”

“…And a classifier algorithm which can detect different causes of flicker was proposed. In [10], the torque and vibration characteristics of the wind turbines drive train during voltage dips were investigated considering the wind shear and tower shadow effects. The other similar researches about this topic are truly seldom reported by now.…”

LVRT Impact on Tower Loads, Drivetrain Torque and Rotational Speed—Measurement Results of a 2-MW Class DFIG Wind Turbine

“…Since the main focus of many publications is on simulations, this publication contains measurement results of mechanical loads and the turbine operation itself, including known risks like over-speed and excitation of the drivetrain eigenfrequency of the turbine [13][14][15].…”