###### Abstract  
The verification of short-circuit effects is very important for ensuring the safety of equipment and power systems. Compared with that in alternating current (AC) systems, research on this issue in direct current (DC) systems is scarce, and it is urgently necessary to develop an accurate verification method for applications in DC systems. This research establishes an equivalent model of a pole-pole cable short-circuit according to the characteristics of low-voltage DC distribution systems in civil buildings. Through theoretical analysis and numerical simulation, the development process of a short circuit is summarized, and the methods of verifying dynamic and thermal effects based on the time-domain characteristics of the short-circuit current are specified. By calculating the peak value and Joule integral of the short-circuit current, in comparison with those in the IEC 61660 (1997) standard, this research points out that the method in the IEC 61660 (1997) standard is insufficient. Finally, the short-circuit peak current is greatly affected by the DC-link capacitance, the steady-state current is directly related to the filter inductance of the AC-link; and the verification of the thermal effect requires the calculation of the Joule integral in the transient and steady state. low-voltage DC; distribution system; short-circuit current; dynamic effect verification; thermal effect verification; Joule integral; civil building 2023  
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and protection selectivity during short circuits. In [19; 20; 21], the researchers studied several fault location methods based on short-circuit currents. Methods of limiting the short-circuit current were proposed by [22; 23; 24]. Many scholars have also studied other related issues. [PERSON] and [PERSON] studied the calculation of various fault currents of \(\pm 750\) V Dc distribution grid [25]. [PERSON] et al. investigated a mid-point grounding system using capacitors to ensure electrical safety in a mono-polar LVDC system in household [26]. [PERSON] et al. discussed the effects of grounding mode on fault characteristics in flexible DC distribution system [27]. [PERSON] et al. presented a fundamental building block for LVdc for different applications in meshed dc grids, which is capable of achieving the given control objectives [28]. [PERSON] et al. proposed a time domain piecewise approximate analytical calculation method for AC-DC hybrid system, when the AC system fails at the receiving end [29]. [PERSON] et al. developed a comprehensive isolation protection device that can quickly cut off the short circuit, and can limit the fault in the fault branch [30]. However, there are some issues that have not been fully studied, and the verification of the dynamic effects and thermal effects of short circuits is one of them. To the best of the authors' knowledge, no published papers have addressed this issue, except for the IEC 61660 (1997) standard [31; 32], which has relevant provisions. If the verification of dynamic effects or thermal effects fails, the devices will be damaged; the accident range will expand when a short circuit occurs, and the system safety will also be destroyed. Therefore, it is a key issue to the power system. For DC system, the IEC 61660-1 (1997) standard [31] provides the calculation method of short-circuit currents, the IEC 61660-2 (1997) standard [32] provides the calculation method of the dynamic effect and thermal effect of short-circuit currents. For AC system, the IEC 60909-0 (2016) standard [33] provides the calculation method of short-circuit currents. However, the method of the IEC 61660 (1997) standard is flawed, which will be explained in detail later. This research analyzes the various stages of short-circuit currents according to the characteristics of low-voltage DC distribution systems in civil buildings, and it provides accurate verification methods for the dynamic and thermal effect according to the time-domain characteristics of the short-circuit current.