电力系统论文.doc

摘要电力系统正常运行的破坏多半是由短路故障引起的,如大的短路电流使元件破损,电压的骤降造成系统解裂甚至崩溃,对周围设备的电磁干扰等。发生短路时,系统从一种状态变到另一种状态,并伴随产生复杂的电磁暂态现象。所以有必要对电力系统发生故障时的电磁暂态进行分析。本设计利用 PSCAD 软件建立相关的电力系统模型,包括:变压器模型、同步发电机模型、输电线模型、负荷模型等。把各个模型搭建在一起,从而得到与数学模型相对应的仿真模型。利用 EMTDC 进行模拟计算,并得到各个参数的曲线,说明各个参数的变化情况,并根据曲线进行比较分析得出结论。本设计建立了简单电力系统和复杂电力系统,并对其重要参数进行分析比较,得出了三相短路是最严重的短路,其次依次是两相接地短路、单相短路和两相短路;系统越复杂则稳定性越好;阻抗越小则电网强度越大等结论。关键词:电力系统;暂态;短路; PSCAD/EMTDC Abstract The electrical power system normal operation destruction is mostly cause dby the short circuit failure. For example, the great short-circuit current enable the element mangle, the voltage to plummet creates the system solution crack even collapse, interfere to periphery equipment and soon. When the short circuit occur s, condition of the system from one change to another, and itance has plex ism transition condition phenomenon. Therefore it is necessity to carry on the analysis to the electrical power system of ism transition condition. This design uses the PSCAD software establish ing electrical power system model, including: Transformer model, synchronous generator model, transmission line model, load model and soon. Each model builds in together, thus obtains the simulation model which corresponds with the mathematical model. Carr yon the putation using EMTDC, and obtain each parameter curve, explain the change situation of each parameter, and carr y on parative analysis according to the curve to draw the conclusion. This design has established the simple electrical power system and plex electrical power system, and carries on the parison to its important parameter, educe the conclusions that the three-phase short circuit is the most serious short circuit, in turn next is two docking short circuits, the single-phase short circuit and two short-circuits; The electrical power system is intricate r then the stability is better ; The impedance is smaller then the work intensity is bigger and soon Keywords : Electrical power system ; transient ; Short circuit ; PSCAD/EMTDC 目