Sequence Domain Harmonic Modeling of Type-IV Wind Turbines

Abstract

Abstract-A sequence domain (SD) harmonic model of a gridconnected voltage-source converter is developed for decoupling converter generated voltage harmonics from voltage harmonics in the external grid. The modeling procedure includes a derivation of the baseband frequency response for regular-sampled pulsewidth modulation and an analysis of converter generated voltage harmonics due to compensated dead-time. The decoupling capabilities of the proposed the SD harmonic model are verified through a power quality (PQ) assessment of a 3MW Type-IV wind turbine. The assessment shows that the magnitude and phase of low-order odd converter generated voltage harmonics are dependent on the converter operating point and the phase of the fundamental component of converter current respectively. The SD harmonic model can be used to make PQ assessments of Type-IV wind turbines or incorporated into harmonic load flows for computation of PQ in wind power plants.

Implementation and Analysis of Mathematical Modeled Drive Train System in Type III Wind Turbines Using Computational Fluid Dynamics

“…During the rotation of the wind wheel, there is a frequent change in the direction and inclination of the blade with respect to the azimuth angle in the case of horizontal axis wind turbine system. The wind shear, rapid wind and other conditions have a significant influence on the wind speed at any particular point on the blade, which is shown in Figure 2 [8].…”

“…2. Wind turbine blade turbulent of wind speed [8] tower shadow effect not only causes 1P aerodynamic load pulsation but also have a certain influence on WT aerodynamic torque. So as to unable the analysis of the relationship between aerodynamic torque and wind speed model, the concept of equivalent wind speed model was introduced in [20].…”

“…A wind direction sensor is used for fi nding out the wind direction, which is instrumental in actuating the yaw control. One of the prime function of the pitch control is to avert or stop the WT from crossing the speed limits so as to keep the operation from going beyond its mechanical limits and the power rating of the generator [8,9]. In this paper, there is an attempt of presenting the comprehensive mechanical control methods which are employed for regulating the wind turbine.…”

Generalized Formulation of Steady-State Equivalent Circuit Models of Grid-Forming Inverters

“…Combining the current limiter formulation (12) into the current control loop formulation (11) yields,…”

“…Their improved computational efficiency allows utility engineers to perform extensive evaluations. For this reason, steady-state models of HVDC converters [7]- [8], grid-following inverters [9]- [10], and type-IV wind generators [11]- [12] have been developed.…”