Download Investigation of the Control of Variable-Speed Constant

Investigation of the Control of Variable-Speed Constant-Frequency WECs
YE Hangye and HE Yikang china
Zhejiang Windey Engineering Co.,Ltd, Hangzhou 310009 China
0086571-87239508/0086-571-87047868/[email protected]
Abstract: the Research project of Megawatt class variable-speed constant-frequency
(VSCF) wind power generation system was listed in national 863 plan (the national hi-tech
research & development project). In this paper, the main research work of this project is
summarized and the key tech-problems are discussed and its characteristics and advantages
are presented.
In the control of VSCF an AC-excited source is required to possess excellent input and output
characteristic and the ability of bi-directional power flowing. On the basis of analysing the
limitation of other converters, the paper points out that the best solution is applying a double
PWM converter. The principles of three-phase voltage -source double PWM converter used as
the AC-excited source of the DFIG is discussed in detail in the paper and experimental results
are offered to prove that the converter is able to fit the requirement very well.
Based on the analysis of wind turbine characteristics, the idea of tracing and capturing
maximal wind energy as well as its performance is investigated. Subsequently, by analyzing
the mathematical model of a doubly-fed induction generator (DIFG) and the field-oriented
vector control scheme, the control strategy of VSCF wind energy generation system are put
forward and the correctness and feasibility are verified by simulation study. The results show
the field-oriented vector control scheme is successful for dis-coupling of p,q in generator, so
the active power and reactive power of the generator for wind power can be regulated
independently, which was met with the demands of tracing and capturing maximal wind
energy.
Key words: VSCF wind energy generation system, the maximal wind energy capture,
field-oriented vector control, AC excitation
Yehangye :Researcher(professor rank)
Chief engineer of Zhejiang Wind Power Engineering Co., Ltd.
Take charge of research and design of 1.5MW variable speed wind turbine (the
863 subject of national tenth five-year plan).