Impact of Increased Penetration of DFIG-Based Wind Turbine Generators on Transient and Small Signal Stability of Power Systems

Abstract

The targeted and current development of wind energy in various countries around the world reveals that wind power is the fastest growing power generation technology. Among the several wind generation technologies, variable speed wind turbines utilizing doubly fed induction generators (DFIGs) are gaining momentum in the power industry. With the increase in penetration of these wind turbines, the power system dominated by synchronous machines will experience a change in dynamics and operational characteristics. Given this assertion, the present paper develops an approach to analyze the impact of increased penetration of DFIGbased wind turbines on transient and small signal stability of a large power system. The primary basis of the method is to convert the DFIG machines into equivalent conventional round rotor synchronous machines and then evaluate the sensitivity of the eigenvalues with respect to inertia. In this regard, modes that are both detrimentally and beneficially affected by the change in inertia are identified. These modes are then excited by appropriate disturbances and the impact of reduced inertia on transient stability performance is also examined. The proposed technique is tested on a large test system representing the Midwestern portion of the U.S. interconnection. The results obtained indicate that the proposed method effectively identifies both detrimental and beneficial impacts of increased DFIG penetration both for transient stability and small signal stability related performance.

Torsional vibration characteristic study of the grid-connected DFIG wind turbine

“…Accordingly, the oscillation mode 4 is the mechanical oscillation mode, and the oscillation frequency is 12.427 Hz. The oscillation mode 5 is highly sensitive to the state variables 3 θ ∆ , 3 ω ∆ , and it is mainly affected by the torsion angle and speed of the high-speed shaft. In addition, it is also affected by the torsion angle and speed of the blades and high-speed shaft to some extent.…”

“…With obvious disadvantages of variable production, however, the large amount of wind turbines integrated to the grid will bring a great impact of low-frequency oscillation and wind turbine shaft torsional vibration on power system [3]. Worse still, the torsional vibration can cause a reduction in the lifespan of the wind turbine resulted from fatigue, even the shaft fault [4], which contributes critically to the stability and safe operation of power system.…”

“…doi:10.1088/1755-1315/52/1/012022 penetration of DFIGs on the power system are studied in [10] by modelling DFIGs as synchronous machines. The researches mentioned above are mainly concentrated on studying the normal operation of DFIG, the impact of DFIGs on the power system and lack the ability of analysing the dynamic characteristics of the DFIG system.…”

The impact of increased penetration of converter control-based generators on power system modes of oscillation

“…Additionally, current utility scale photovoltaic (PV) plants are full converter control based systems. Therefore, the impact of the increasing penetration level of these new converter control based generators (CCBGs) on the security and reliability of the power system has been the subject of recent research [1][2][3][4][5][6].…”

“…Jaime Quintero is on leave of absence from Universidad Autónoma de Occidente, Cali, Colombia. the modes) [4][5][6][7][8][9]:…”