Grid interaction of offshore wind farms. Part 1. Models for dynamic simulation

Abstract

In this contribution, dynamic wind farm models suitable for fast simulation of power systems are presented. While deriving the models, special attention has been paid to increasing the computational speed of the simulation program. An important increase in speed is realized by the use of the well-known dq0 transformation (Park transformation) not only for the generator but also for all other electrical components. The use of the Park transformation is common practice in electrical machine models, but not in the modelling of other electrical components. For single turbines, simulations in the dq0 reference frame are 100 times faster than simulations in the abc reference frame. After a discussion of the Park transformation and its most important properties, it is explained how models in the dq0 reference frame can be obtained.The dq0 models of the most important electrical components are presented. The mechanical and aerodynamic models that are needed for dynamic simulation of wind turbines are discussed briefly. The models are applied in Part 2. Ê Ëˆ[ ] q q 268 J. Morren et al.

Investigation of voltage sag impact on wind turbine tower vibrations

“…8 In spite of the short duration of voltage sags, such events can cause serious problems for a wide range of equipment such as process-control equipment, computers, adjustable-speed drives and wind turbines. 3,4,[9][10][11] Voltage sags are of a stochastic nature as most of them are caused by remote short-circuit faults occurring in transmission and distribution systems and involving several random factors such as fault position, fault type, pre-fault voltage, etc. 12 As a single event, a voltage sag is characterized by its magnitude (the residual voltage during the event) and its duration (the time during which the RMS voltage stays below a given threshold, usually 0.9 pu).…”

Control of DFIG under Unsymmetrical Voltage Dip

“…The complete DFIG system with controllers is modeled in Matlab/Simulink [3]. These models are developed in the synchronous rotating reference frame in order to improve the simulation speed, because the balanced three phase voltage and current in the synchronous rotating reference frame are DC values at steady state.…”

“…Because of its ability to provide variable speed operation and independent active and reactive power control in a costeffective way, the doubly fed induction generator (DFIG) has the largest world market share of wind turbine concepts since the year 2002 [1]. Many researches have studied the low voltage ride through (LVRT) capability of DFIG [3] [4] [5] [6] [7] , most of them are focused on the behaviors and protections of DFIG under symmetrical fault. Transient over current in the rotor is identified as the most severe LVRT problem of the DFIG, because the rotor side voltage source converter (VSC) is very sensitive to thermal overload.…”

Grid-connected and islanded operation of a hybrid power system

“…Dynamic models are developed in the synchronous rotating reference frame in order to improve the simulation speed, because the balanced three phase voltage and current in the synchronous rotating reference frame are DC values at steady state. [15]. Some important control tasks of this hybrid power system are simulated.…”