【作者】 万庆祝；

【导师】 王赞基；

【作者基本信息】 清华大学 ， 电气工程， 2008， 博士

【摘要】 目前我国正在大力发展电气化高速铁路。随着大量铁路线路和高速机车的投入运行,牵引供电系统对电力系统电能质量的负面影响也越来越严重。电气化铁道对电力系统的影响主要有:负序与谐波。负序问题的研究,包括负序分析、传播特性和负序补偿等,是电气化铁道工作者研究的重点课题。为了能对牵引供电系统产生的负序进行分析,本文首先设计并开发了包括列车牵引计算模块和牵引供电系统潮流计算模块在内的综合仿真软件,给出了仿真系统的主体流程,分析并实现了牵引变电所馈线电流的仿真计算。分析比较了求解交流牵引供电系统潮流的现有方法,针对其R/X较大的特点,通过改进支路,采用PQ分解法求解了系统潮流,且实验验证表明该方法性能优良,是求解牵引供电系统负序问题的有效方法。为了分析牵引负荷产生的负序电流及所需无功补偿容量的大小,采用基于磁势平衡方程、绕组接线方程、输出端口方程和电压传递方程的系统化方法,详细分析了单相接线、星形三角形接线、阻抗匹配平衡接线、Scott接线牵引变压器的电气特性,建立了它们的节点导纳矩阵。同时设计了平衡牵引变压器负序电流非对称补偿的统一数学模型,为设计牵引变压器的接线型式提供了理论指导。以Yd11接线型式的牵引变压器为例,分析比较了分别在牵引变电所一次、二次侧装设无功功率补偿装置校正功率因数时,负序电流及所需无功补偿容量的大小,为补偿方式的改进和优化等提供了理论依据。采用Steinmetz补偿电路是解决电气化铁道负序的成熟、有效办法,针对Steinmetz补偿电路实现三相平衡所需补偿容量很大的问题,以三相补偿装置总容量最小为目标,运用优化方法提出了一种合理的补偿容量最优方案,并推导了最优补偿容量的解析结果。通过MATLAB计算,与Steinmetz电路所需补偿容量进行的比较,表明在满足性能要求前提下,上述结果在补偿容量数值上有明显优势。计算实例表明,所提出的优化设计方案能以较小的补偿容量达到较好的补偿性能。更多还原

【Abstract】 With the rapid development of China’s high speed electrified railway, traction power supply system will cause more severe power quality problems. These power quality problems mainly focus on two aspects: negative phase sequence (NPS) and harmonics. The NPS problem including its analysis, its transmission and its compensation is one of the most important topics for researchers.In order to evaluate the NPS problem caused by traction power supply system, this dissertation describes in detail how to design and develop integrative simulation software including traction calculation module and power system power flow calculation module firstly; provides the main structure of the simulation system; figures out how to realize the simulation calculation of traction substation’s feeder. A comparative analysis on the existing methods of load flow computation for traction power systems is conducted. Considering the property of large R/X, the dissertation adopts PQ decoupled load flow algorithm to solve the traction power system via improving on the branch, and applies the algorithm in a practical system. The result of the calculation shows that this algorithm possesses good performance and can be effectively applied to solve NPS problem for AC electrified railway.In order to analyze NPS current caused by traction substation and reactive-power compensation capacity, a systematic method based on the magnetomotive force balance equations, winding connection equations, output-port equations and voltage transfer equations are adopted to analyze the operational performance of the single-phase, the wye-delta, the wye-prolonged delta, the Scott, connection transformers. The nodal admittance matrices of these transformers are set up. Meanwhile, unified mathematical model of non-symmetrical compensation is designed to balance NPS current caused by traction substation, which provides the theories leading for devising traction substation. Based on the wye-delta connection transformer, NPS current caused by traction substation and reactive-power compensation capacity are analyzed when reactive-power compensating devices are implemented in the primary or secondary side of the traction transformer respectively to correct power factor, which provides the theories leading for devising the compensation mode.Steinmetz circuit is effectively used for settling NPS problem caused by electrified railway, however which requires a quite large compensation capacity. Therefore proposed an optimal algorithm in this dissertation, its target is set to make three-phase compensation capacity lowest. By solving the mathematical problem with optimal method analytical results of the compensation capacity are obtained. Comparisons between the optimal results and that of the original Steinmetz circuit are made with MATLAB simulations, which demonstrate the advantages of the optimal design while meet the performance request. The calculation results show the system can be balanced by the optimal capacity with acceptable performance and less cost.更多还原