中性点不接地系统单相接地故障分析与仿真

在小电流接地系统中,当出现单相接地故障的时候,因为它构不成短路回路,负荷电流比接地短路产生的电流大得多,而故障相的对地电压本身又小得多,所以故障相的对地电压以及非故障相的相电压均发生变化,前者降低、后者升高,但线电压却依然是对称的,所以用户依然能够不受影响地使用电能,在该系统下可维持运行1到2小时。因为单相接地是一种比较容易见到的故障类型,所以在该文中,采用Matlab仿真软件,模拟小电流接地系统(这里仅对中性点不接地系统进行分析)单相接地故障,建立仿真模型,通过设置电源、线路等参数以及仿真参数,模拟出了仿真结果及系统各个主要参数的波形图,最后根据仿真结果,得出重要结论。

Ungrounded System Single-phase Ground Fault Analysis and Simulation

In the small current grounding system,when there is a single phase to ground fault,it did not con- stitute a short circuit,ground fault current load current ratio produced much larger,and the fault phase-to-ground voltage which in turn is much smaller.Therefore,the phase voltage relative to ground fault and non-fault phase voltages are changed,the former is decreased,the latter increased,but line voltage is still symmetrical,the user can still do not affected to use the power,the system can be maintained to run 1-2 hours.Because single-phase ground is a common type of fault,the Matlab simulation software is used to simulate the small current grounding system single-phase ground fault simulation model in this article （where only ungrounded systems analysis）,the establishment of the simulation model,through the power lines and other simulation parameters and parameter settings,simulated waveforms for each of the major parameters of the simulation results and the system.Finally,according to the simulation results,important conclusions are drawn.