Research And Application Of Dual-mode Operation Control For 2MW Doubly-fed Wind Turbine

At present,the wind power technology in China has been in the forefront of the world after many years of development.With the arrival of the parity of the wind power online price and the continuous reduction of the wind power market bid price,the wind energy resources faced by the newly installed units are not optimal already,most of which are the scene of the low wind speed resources.At the same time,the units that have been connected to the grid many years ago first occupy the superior wind resources,but their installed capacity is generally low,and the maximum utilization of wind energy is not high.More common on the market at present the unit for the doubly-fed wind turbine and permanent magnet direct drive units,doubly-fed generator for its stable and mature technology and price advantage,occupies important role in the market,in order to further improve economic efficiency,low wind power generation for traditional doubly-fed generator at low wind speed cannot be connected to the grid to study this phenomenon,combined with the advantage of permanent magnet direct drive unit,A "dual mode" power generation operation mode is adopted and analyzed in detail.Firstly,the components and common control strategies of the doubly-fed wind turbine are introduced,the basic control principle and mathematical model of the converter are analyzed,and the system design plan and key component selection of the2 MW doubly-fed wind turbine are further elaborated.Secondly,by comparing the advantages and disadvantages of doubly-fed wind turbine and permanent magnet direct drive wind turbine,a kind of dual-mode doubly-fed wind turbine topology is adopted,and the converter control strategy under low and high speed is analyzed in detail.Based on the MATLAB/Simulink simulation platform,the electrical simulation model of the dual-mode doubly-fed unit was constructed,and the relevant variables such as voltage and current of the motor stator and rotor were simulated at different speeds,which verified the effective improvement of the power generation efficiency of the dual-mode doubly-fed unit at low wind speed.Finally,in order to further improve the power generation at low speed,a test platform for dual-mode dourely-fed unit is built to optimize the control strategy of the original unit,and the average speed monitoring function is added to the improved control strategy of the unit.Through simulation and measured data,the minimum grid-connected speed of the 2MW dual-mode dourely-fed unit can be reduced to 520r/min.It is 13.3% higher than the current minimum grid-connected speed of the general unit 600r/min,which has certain practical application value.Figure 62 Table 5 Reference 82...