电气设计中线缆选择校验方法

Selection and Calibration Method for Insulating Conductor and Cable in Electrical Design

短路是工程设计中必须严密关注的故障状态,短路时导体会在极短时间内产生大量的热量.因此,选择线路型号与规格后需要进行绝缘导体在短路状态下的热稳定性校验.分析了绝缘导体在短路状态下的发热与散热平衡过程,从而导出其短路时热稳定的条件.通过对热稳定条件分析,提出了设计中热稳定校验的几种方法,并指出电气工程设计中实际采用的可靠方法.

In engineering design,attention should be paid to short circuit.While short circuit happens, lots of heat is produced in a very short period of time.Therefore,its thermal stability calibration is needed in short circuit condition after conductor is chosen.In this paper,heating and cooling bal- ance process of insulating conductor is analyzed in short circuit state,and conditions of thermal stability are concluded.Through the analysis of thermal stability conditions,the methods to meet short-circuit thermal stability in design are given,and practical and reliable methods are indicated.