新型高压直流输电系统仿真研究.doc

新型高压直流输电系统仿真研究 摘要 新型高压直流输电系统是以电压源换流器(VSC) 为基础在新型高压直流输电的拓扑模型中灵活转变。新型高压直流输电系统与传统高压直流输电系统相比较来说有很多优势，比如：输送容量大、送电距离远、输电线路造价低、能量损耗小和控制方式灵活快速。使其在这个行业中发展迅猛,对电网互联的跨区域发挥了主要作用，所以新型高压直流输电系统稳定和安全的运行对于工业生产和社会生活有着重要的影响意义。而在新型高压直流输电系统中，本文主要研究柔性直流输电系统即VSC-HVDC。 高压直流输电系统的控制方式是保持高压直流输电系统稳定性的主要方式,换流器触发控制和分接头控制是高压直流输电控制系统的核心内容,它通过控制高压直流输电系统中主要组成部分的换流设备来保证高压直流输电系统的正常运行及其故障后恢复的迅速性,所以对于换流器触发控制和分接头控制进行研究对保证高压直流输电系统的稳定又安全的运行有着主要意义。 本文基于交直流电网仿真系统与仿真平台建立新型高压直流输电一次系统仿真模型,基于一次系统仿真模型和高压直流输电基本控制原理,在分析新型高压直流输电控制系统基础上建立控制系统仿真模型建立了能够反映VSC-HVDC内部特性和物理过程的数学模型。该模型中计及了换流变压器的不同变比及三相电网电压的不平衡,具有一般性。仿真结果表明该模型在具有很高准确度的同时,还能显著缩短仿真时间,提高仿真效率。关键词：  New type of high-voltage direct current transmission system simulation ABSTRACT New high-voltage direct current transmission is based on voltage source converter (VSC) is a new type of high voltage direct current transmission (VSC - HVDC) the topological structure of complex changes. High-voltage direct current transmission system, with its large conveying capacity, transmission distance, transmission line low cost, low energy consumption advantages of fast and flexible control mode in the rapid development in the world, is the main mode for inter-district grid interconnection, So the high-voltage direct current transmission system stability and safety of operation for industrial production and social life has the very vital significance. High-voltage direct current transmission control system is to keep the important means of high-voltage direct current transmission system and stable operation, The inverter control of converter transformer tap in and control is the core part of high-voltage direct current transmission control system, Through the control of the high-voltage direct current transmission system converter equipment to ensure the normal operation of the high-voltage direct current transmission system and the back quickly after the failure, So for the inverter control and converter transformer tap control study to guarantee stable and reliable running of