Conference Paper

Reactive power analysis and control of doubly fed induction generator wind farm

Conference: Power Electronics and Applications, 2009. EPE '09. 13th European Conference on
Source: IEEE Xplore

ABSTRACT Power relations of doubly fed induction generator (DFIG) wind power generation system are analyzed. Based on this, a method is proposed to calculate the reactive power limit. Furthermore, the reactive power control of DFIG wind farm is studied and the control scheme is provided to exert the reactive power dealing capability of wind power system. A reactive power compensation strategy for the local user using DFIG wind farm and the distribution algorithms of reactive power demand are given. Simulation results are provided to verify the proposed theory.

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    ABSTRACT: With the development of wind power, the construction of large-scale wind farms has became an inevitable trend, however, it brings many reactive power/voltage problems of wind farms which connect to power grid. This paper respectively analyzes the reactive power/voltage characteristics of the current mainstream wind generators, large-scale wind farm and cluster wind farms. It is to do a detailed analysis of the single wind farm voltage controlling and proposes automatic and coordinate voltage controlling measures by the judgments of the voltage/reactive power sensitivity matrix which represent the stability of power system. Simulation results of the power grid with wind farm integration before and after using the control measures show that automatic voltage control measures can narrow the range of the voltage fluctuation and reduce line losses in the region significantly.
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    ABSTRACT: This paper presents an improved grid voltage control strategy for wind farms with doubly-fed induction generators (DFIGs) connected to distribution networks based on an analysis of the operation limits of DFIG systems. A modified reactive power limit calculation method in different operation states is proposed and a reactive power control strategy during grid voltage dips/rises is further discussed. A control strategy for compensating unbalanced grid voltage, based on DFIG systems, by injecting negative sequence current into the grid through the grid side converter (GSC) is proposed. In addition, the negative current limit of the GSC is discussed. The distribution principle of the negative sequence current among the different DFIG systems in a wind farm is also introduced. The validity of the proposed voltage control strategy is demonstrated by Matlab/Simulink simulations. It is shown that the stability of a wind farm and the power grid can be improved with the proposed strategy.
    Journal of power electronics 01/2012; 12(3). · 0.78 Impact Factor