The Impact Of Distributed Wind Power On Composite Load Characteristic Of Distribution Network

The power system simulation is very important in the designing, operating and analyzing of power system. The accurate degree of simulation results relates to the secure and stable operating of power system. Because the power system load has the characteristics of time-varying, distributivity, randomicity, multiformity, it is very difficult to build a load model which has good adaptable and high accurate.With the rapid development of wind power technology and the importance of renewable energy power generation which the state policies attach to, the construction of wind power in China has entered a period of rapid development. The grid-connected wind power generation impacts the power system on power quality, transient stability, voltage regulation, frequency regulation, and many other issues. Researching from the perspective of load modeling, as a typical distributed power, if wind power is equivalent to the part of composited load considering distribution network, the impact will exist on the composite load model and its identified parameters, which can affect the accuracy of power system simulation. This paper applies the measured data of simulation and the theory of measurement-based method, traditional composite load model of distribution network, generalized load model considering the impact of small source and generalized composite load model considering distribution network and reactive power compensation are utilized to identify.The impact of wind power generation on load model are analyzed by comparing the model self-description capability, the generalization capability and the stability of identified parameters. The results show that the generalized composite load model considering distributed network and reactive power compensation has a better descriptive ability on composite load considering wind power generation.The impact of wind power on load model description ability behaves that it changes the regional load characteristic, but the analysis of this issue is still in qualitative analysis phase now. Using the proposed quantitative indicators, this paper analyes the impact of different operation modes of wind power on the comprehensive load characteristic. The main factors of load characteristic are the capacity and the location of wind power. According to the measured data of simulation, two factors were compared. The results show that the more the capacity of WPG, the more the impact on load characteristic; the higher the proportion of active power where WPG accesses to, the smaller the impact on load characteristic; the farther the distance between WPG and the equivalent load bus, the smaller the impact on load characteristic; When the capacity proportion of WPG is less than 20%, the impact of location on load characteristic is more than the impact of capacity; When the capacity proportion of WPG is more than 20%, the impact of capacity on load characteristic is more than the impact of location.