Analysis And Modeling Of Mid-frequency Furnace Load Characteristics

Before June 2016,Yunnan power grid through 4 back 500kV AC line and the South China Power Grid connected to the main network,there is basically no frequency stability.After June 2016,Yunnan Power Grid and China Southern Power Grid to achieve asynchronous network.After asynchronous networking,the stability of the Yunnan power grid has undergone great changes.Compared with the asynchronous networking before,the power angle stability problem is weakened,and the frequency stability problem is prominent.It is well known that the load model(especially the load frequency characteristic)has a significant effect on the grid frequency stability characteristics.Yunnan load model has been extended several decades ago with the load model,the load model has been unable to reflect the actual.The load capacity of the intermediate frequency furnace and its model have important theoretical and practical significance to study the load characteristics of the whole Yunnan.The intermediate load furnace has a large proportion of the load capacity in the load of Yunnan.In this paper,according to the actual production process of intermediate frequency furnace and the circuit principle of its load characteristics of the study.In the course of the study,the load characteristics of the intermediate frequency furnace,which does not take into account the distribution network,are studied first,and then the overall load characteristics after the distribution network are studied.The load frequency and voltage factor are deduced in two different cases,and the simulation results are analyzed by MATLAB/Simulink,the simulation results are in agreement with the theoretical deduced load factor.The results show that the load frequency characteristics of the intermediate frequency furnace are not significantly changed before and after the distribution network,and the voltage characteristic is changed obviously.Based on the study of the load characteristics of the intermediate frequency furnace,the load modeling of the intermediate frequency furnace is studied,and the load model combined with the constant power and the constant impedance is considered.The load characteristics of the equivalent load model are simulated by MATLAB/Simulink.The results show that the load characteristics of the equivalent load model considering the distribution impedance intermediate frequency furnace load characteristics are more similar,and can more directly reflect the load node load characteristics.Therefore,the equivalent load factor model can be used to reflect the load characteristics of the intermediate frequency furnace.Finally,the relationship between the length of the distribution network and the equivalent load model is discussed.The results show that the influence of the distribution impedance on the equivalent load model can be neglected when the length of the distribution network is less than lkm.When the distribution length is more than lkm,The influence of the distribution network should be considered when studying the load characteristics of the equivalent integrated load model.