Voltage and Reactive Power Control of Front-end Speed Controlled Wind Turbine via H∞ Strategy

Adaptive disturbance observer‐based control for stochastic systems with multiple heterogeneous disturbances

“…The front‐end speed controlled wind turbine (FSCWT) was put forward by VOITH company in 2005. Different from the traditional rigid driving mode, the hydraulic torque converter is adopted in the transmission chain, which makes the synchronous generator directly coupled to the grid power similar to the conventional hydropower and thermal power . The structure diagram of FSCWT is shown in Figure .…”

“…In the EESG structure, the rotor direct axis ( d ‐axis) has an objective excitation winding f and an equivalent damping winding D , the quadrature axis ( q ‐axis) has two equivalent damping winding, winding Q and winding . The current and rotational speed are seen as the state vectors in the operation environment of FSCWT, which can be described as x ( t )=[ i d ; i q ; i o ; i f ; i D ; i Q ] T . Similar to the works of Rubio et al and Dong et al, the detailed modeling for the wind turbine is as follows.…”

“…The current and rotational speed are seen as the state vectors in the operation environment of FSCWT, which can be described as x ( t )=[ i d ; i q ; i o ; i f ; i D ; i Q ] T . Similar to the works of Rubio et al and Dong et al, the detailed modeling for the wind turbine is as follows.…”

“…Considering that the external complex environment and internal electromagnetic environment change is inevitable, the electromagnetic disturbance is generated in the process of the synchronous generator running and affected the current and rotational speed of wind turbine system, which can be described as additive white noises. In addition, the multiplicative noise disturbance is produced in the process of the rotor running, that is, the disturbance is coupled with the state of the system, which seriously affects the efficiency of the wind turbine . From what has been discussed above, the state space model of the FSCWT with disturbance can be described by system .…”

Coordination Control of FSCWT for Enhancing LVRT Capability Using Hierarchical Multi-object Predictive Strategy

“…To exemplify the superiority of the proposed method, a comparison of the proposed method and H ∞ strategy, proposed by the authors for the same purpose [21], which is shown in Figure 11. …”