A vector-controlled doubly-fed induction generator for a variable-speed wind turbine application

Abstract

This paper examines the performance of a vector-controlled doubly-fed induction generator for wind turbine use. The scheme is considered for variable-speed-range applications to produce a greater wind energy capture from varying wind velocity. A major advantage of the doubly-fed scheme over the squirrel-cage generator is the reduced volt-ampere rating of the power converter used to control the rotor current. The singly-fed scheme requires that the power converter is able to carry the full generator output. In order to produce decoupled regulation of active and reactive output power, the rotor current is controlled using field orientation principles. The measurement of rotor position and the grid voltage vector position allows the rotor current to be controlled in a reference frame closely associated with the stator magnetising current. The stator active and reactive power are also measured and fed back into outer Ps and Qs control loops. The Ps and Qs controllers produce d and q axis rotor current demands for the inner rotor current vector controller. By control of the reactive power loop the generator can be made to produce power at unity power factor. The vector control of rotor current is carried out using a commercial PWM inverter equipped with vector control hardware as standard. The inverter also produces a unity power factor sinusoidal current interface to the grid network. The performance of the scheme is examined using both simulation and experimental results. The decoupling control of active and reactive power is demonstrated and shows the ability to generate power at unity power factor.

Integrating Wind Farm to the Grid Using Hybrid Multiterminal HVDC Technology

“…The control strategies concerned with the two converters have been well-illustrated in many papers such as [22] and [23]; no more details are given here.…”

The modeling and numerical simulations of wind turbine generation system with free vortex method and simulink

“…Now, more and more researchers realized that the steady model of wind turbine is not sufficient when the dynamic behaviors of the machine during the disturbance are concerned [4]. The earlier dynamic modeling work could be found in [5]. In this paper, a vector control was proposed in wind turbine application.…”

“…In [7], the theoretical analysis of DFIG dynamic behaviors during voltage dip was proposed. However, only the DFIG dynamic behaviors were mostly concerned in [3][4][5][6][7]. Recently, an improved sensorless decoupled control method is proposed in [8].…”

Modeling and analysis of reactive power in grid-connected onshore and offshore DFIG-based wind farms

“…7,8,[11][12][13][14] By utilizing the reactive power control capability of DFIG, DFIG-based wind farms can be used as a continuous reactive power source to support system voltage control. 7,[14][15][16][17] Details about wind turbine concepts and their comparison can be found in the work of Li and Chen. 11 As the wingspan and the height of wind turbines have grown, it has become difficult to find acceptable locations to erect these wind turbines, especially in densely populated countries.…”