中频炉负荷特性分析及建模研究

发布时间：2018-09-12 14:16

【摘要】：2016年6月前,云南电网通过4回500kV交流线路与南方电网主网相连,发生解列导致高频的概率较小,仅在多回直流同时双极闭锁等复杂故障下才存在解网的可能。2016年6月以后云南电网和南方电网主网实现异步联网,异步联网后,云南电网的稳定特性发生了很大的变化。与异步联网前相比,功角稳定问题减弱,而频率稳定问题突出。众所周知,负荷模型(特别是负荷频率特性)对电网频率稳定特性有显著的影响。云南电网负荷模型一直延用几十年前的负荷模型,负荷模型已不能反映实际。云南电网负荷中高载能负荷占有较大比重,中频炉在冶炼、制造等高载能行业广泛应用,研究中频炉负荷特性及其模型对研究整个云南负荷特性有重要的理论与实际意义。本文根据中频炉实际生产工艺以及电路原理对其负荷特性展开了研究。在研究过程中,先研究了不考虑配电网络的中频炉负荷特性,然后研究了计及配电网络后的总体负荷特性。对两种不同情况下负荷频率和电压因子进行了推导,并利用MATLAB/Simulink对其进行仿真分析,仿真所得结论与理论推导所得负荷特性因子一致。结果表明,考虑配电网络前后,中频炉负荷频率特性无明显变化,而电压特性变化较明显。在研究中频炉负荷特性基础上,进行了中频炉负荷建模研究,考虑了恒功率与恒阻抗相结合的负荷模型、综合负荷模型两种情况。利用MATLAB/Simulink仿真表明,考虑配网阻抗在内的等效综合负荷模型负荷特性与实际中频炉负荷特性更相近,且能更直接地反映负荷节点负荷特性。因此,可采用等效综合负荷模型负荷特性因子反映中频炉负荷特性。最后,对配网长度与等效综合负荷模型的关系进行了讨论,结果表明,当配网线路长度小于1km时,可忽略配网阻抗对等效负荷模型产生的影响;而当配网线路长度大于1km时,则在对等效综合负荷模型负荷特性研究时,应该考虑配网影响。
[Abstract]:Before June 2016, Yunnan Power Grid was connected to the main network of Southern Power Grid through four 500kV AC lines, which resulted in a low probability of high frequency. After June 2016, the asynchronous network between Yunnan Power Grid and Southern Power Grid has been realized. After asynchronous interconnection, the stability characteristics of Yunnan Power Grid have changed greatly. Compared with before asynchronous interconnection, the power angle stability problem is weakened, while the frequency stability problem is prominent. It is well known that the load model (especially the load frequency characteristic) has a significant influence on the frequency stability of the power network. The load model of Yunnan power grid has been used for decades, but the load model can not reflect the actual situation. The load of Yunnan power grid occupies a large proportion of the high energy load, and the if furnace is widely used in smelting, manufacturing and other high-load energy industries. It is of great theoretical and practical significance to study the load characteristics and its model of the intermediate frequency furnace in Yunnan Province. In this paper, the load characteristics of if furnace are studied according to its actual production process and circuit principle. In the research process, the load characteristics of if furnace without considering the distribution network are studied first, and then the overall load characteristics after considering the distribution network are studied. The load frequency and voltage factor under two different conditions are deduced and simulated by MATLAB/Simulink. The simulation results are consistent with the load characteristic factors derived from the theoretical analysis. The results show that before and after considering the distribution network, the load frequency characteristic of if furnace has no obvious change, but the voltage characteristic is obvious. On the basis of studying the load characteristics of intermediate frequency furnace, the load modeling of intermediate frequency furnace is studied. The load model combined with constant power and constant impedance is considered, and the integrated load model is considered. The MATLAB/Simulink simulation shows that the load characteristics of the equivalent integrated load model, including the impedance of the distribution network, are closer to those of the actual if furnace, and can reflect the load characteristics of the load node more directly. Therefore, the load characteristic factor of the equivalent integrated load model can be used to reflect the load characteristics of intermediate frequency furnace. Finally, the relationship between the distribution network length and the equivalent integrated load model is discussed. The results show that the influence of the distribution network impedance on the equivalent load model can be ignored when the distribution line length is less than 1km, and when the distribution line length is larger than 1km, The influence of distribution network should be taken into account when studying the load characteristics of equivalent integrated load model.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM714;TM743

【参考文献】