直流网状网络短路电流计算

Short-circuit Current Calculation for DC Meshy Network

为了解决舰船电力系统主网多电站短路电流的计算,根据其直流网状网络的特点,给出了一种有效的短路电流计算法。该方法用星网等值变换,将直流网状网络简化为各发电机通过整流器直接与短路故障点通过阻抗相连的形式,从而得到它们之间简单的电量关系,然后将直流侧突然短路等效为发电机三相对称短路,通过直流侧阻抗折算到交流侧的等值关系,计算母线上短路时的短路电流。仿真结果表明,该算法准确度较高,满足工程实际要求,可以用来计算直流网状网络的短路电流,为系统的保护设计提供依据。

According to the characteristics of naval DC meshy network, a simple and effective short current calculation method is given. It simplifies meshy network in the form that electrical sources and fault connect dircctly by rectifier and impedance. Because the de side short circuit is equivalent to balanced three phase short circuit on the ac side,then by the equivalence relation of dc impedance to ac impedance,calculate the short-circuit currents when the bus have a fault. The result of simulation indicates that the method is accurate enough for engineering.