Research On Generalized Load Modeling Of Distribution Network Considering Distributed Energy Access

With the increase of penetration rate of distributed power sources,traditional load model may bring a large error.It is necessary to further consider the characteristics of the distributed power supply in the load model.This paper firstly discussed the background and research significance of the topic.The development and current status of generalized load modeling research were expounded and analyzed from five aspects: load modeling method,load model,system identification theory,traditional load modeling research and generalized load modeling research.Subsequently,the PV and wind power models were further analyzed in detail.The response of each internal variable in the PV and wind power fault process and the active and reactive response curves reflected by the external process were deduced and analyzed in detail.The mechanism of considering the reactive power support of the inverter and the capacity limitation of the inverter on the fault response of various distributed power sources was discussed and analyzed in more depth.Then,the generalized load model was established and the faults in different scenarios were identified,and the effectiveness of the proposed model and identification method were verified.Furthermore,the timevarying problem which was more difficult to describe than the traditional load in generalized load modeling was analyzed.The clustering method was used to cluster complex scenes,and the fault samples were identified and then classified to select the model parameters.The results showed that the proposed method grasped the main contradiction of load time-varying,and could cluster complex scenes well and systematically gave out the selection method of a prior model parameters.Since the mechanism model was more difficult to describe the complex composition of the distribution network,this paper proposed to use the non-mechanical model for modeling.This paper first reviewed and summarized the non-mechanical load model,and discussed the advantages and disadvantages of the non-mechanical model in generalized load modeling.The generalized load was further modeled by the neural network model and its characteristics were summarized.In this paper,it was further proposed that in order to improve the model generalization ability of the non-mechanical model considering the reactive power support of the inverter and the capacity limitation of the inverter,the non-mechanical model was modeled according to the idea of piecewise function fitting.The simulation results showed that the proposed method can improve the generalization ability and stability of non-mechanical models in generalized load modeling.Lastly,the article analyzed and compared the similarities and differences between generalized load modeling and multi-microgrid equivalents,and study the dynamic characteristics of microgrids under different microgrid control strategies(master-slave model)and different micro-power control methods(PQ、VF、 droop).