This paper introduced the status quo of wind power and wind power generation technology. Focusing on the introduction of wind power generating system ibrational self-consistent field（VSCF）, program implementation in...This paper introduced the status quo of wind power and wind power generation technology. Focusing on the introduction of wind power generating system ibrational self-consistent field（VSCF）, program implementation included Alternating Current （AC）-Direct Current （DC）-AC conversion system, magnetic field modulation generator system, doubly-fed generator system etc. Among these, doubly-fed generator system is the trend. Where to build the wind farm is very important, so a perfect site is needed. Wind power generation will have a bright future. As long as the wind power can be linked to the grid in large scale.展开更多
Doubly-Fed Induction Generator （DFIG）, with vector control applied, is widely used in Variable-Speed Constant- Frequency （VSCF） wind energy generation system and shows good performance in maximum wind energy captu...Doubly-Fed Induction Generator （DFIG）, with vector control applied, is widely used in Variable-Speed Constant- Frequency （VSCF） wind energy generation system and shows good performance in maximum wind energy capture. But in two traditional vector control schemes, the equivalent stator magnetizing current is considered invariant in order to simplify the rotor current inner-loop controller. The two schemes can perform very well when the grid is in normal condition. However, when grid disturbance such as grid voltage dip or swell fault occurs, the control performance worsens, the rotor over current occurs and the Fault Ride-Through （FRT） capability of the DFIG wind energy generation system gets seriously deteriorated. An accurate DFIG model was used to deeply investigate the deficiency of the traditional vector control. The improved control schemes of two typical traditional vector control schemes used in DFIG were proposed, and simulation study of the proposed and traditional control schemes, with robust rotor current control using Internal Model Control （IMC） method, was carded out. The validity of the proposed modified schemes to control the rotor current and to improve the FRT capability of the DFIG wind energy generation system was proved by the comparison study.展开更多
This paper presents a scalar volt per hertz(V/f)control technique for maximum power tracking of a grid-connected wind-driven brushless doubly fed reluctance generator(BDFRG).The proposed generator has two stator windi...This paper presents a scalar volt per hertz(V/f)control technique for maximum power tracking of a grid-connected wind-driven brushless doubly fed reluctance generator(BDFRG).The proposed generator has two stator windings namely;power winding,directly connected to the grid and control winding,connected to the grid through a bi-directional converter.In order to enhance the performance of the proposed scalar-control strategy,a soft starting method is suggested to avoid the over-current of the bi-directional converter.Moreover,the capability of generator speed estimation for sensorless control is also studied.The capability of the proposed scalar-control technique is validated using a sample of simulation results.In addition,the presented simulation results ensure the effectiveness of the proposed control strategy for maximum wind-power extraction under windspeed variations.Furthermore,the results show that the estimated generator speed is in a good accordance with the actual generator speed which supports sensorless control capability.展开更多
文摘This paper introduced the status quo of wind power and wind power generation technology. Focusing on the introduction of wind power generating system ibrational self-consistent field（VSCF）, program implementation included Alternating Current （AC）-Direct Current （DC）-AC conversion system, magnetic field modulation generator system, doubly-fed generator system etc. Among these, doubly-fed generator system is the trend. Where to build the wind farm is very important, so a perfect site is needed. Wind power generation will have a bright future. As long as the wind power can be linked to the grid in large scale.
基金Project (No.50577056) supported by the National Natural Science Foundation of China
文摘Doubly-Fed Induction Generator （DFIG）, with vector control applied, is widely used in Variable-Speed Constant- Frequency （VSCF） wind energy generation system and shows good performance in maximum wind energy capture. But in two traditional vector control schemes, the equivalent stator magnetizing current is considered invariant in order to simplify the rotor current inner-loop controller. The two schemes can perform very well when the grid is in normal condition. However, when grid disturbance such as grid voltage dip or swell fault occurs, the control performance worsens, the rotor over current occurs and the Fault Ride-Through （FRT） capability of the DFIG wind energy generation system gets seriously deteriorated. An accurate DFIG model was used to deeply investigate the deficiency of the traditional vector control. The improved control schemes of two typical traditional vector control schemes used in DFIG were proposed, and simulation study of the proposed and traditional control schemes, with robust rotor current control using Internal Model Control （IMC） method, was carded out. The validity of the proposed modified schemes to control the rotor current and to improve the FRT capability of the DFIG wind energy generation system was proved by the comparison study.
文摘This paper presents a scalar volt per hertz(V/f)control technique for maximum power tracking of a grid-connected wind-driven brushless doubly fed reluctance generator(BDFRG).The proposed generator has two stator windings namely;power winding,directly connected to the grid and control winding,connected to the grid through a bi-directional converter.In order to enhance the performance of the proposed scalar-control strategy,a soft starting method is suggested to avoid the over-current of the bi-directional converter.Moreover,the capability of generator speed estimation for sensorless control is also studied.The capability of the proposed scalar-control technique is validated using a sample of simulation results.In addition,the presented simulation results ensure the effectiveness of the proposed control strategy for maximum wind-power extraction under windspeed variations.Furthermore,the results show that the estimated generator speed is in a good accordance with the actual generator speed which supports sensorless control capability.
