电缆接头温度反演及故障诊断研究

Research on Temperature Retrieval and Fault Diagnosis of Cable Joint

为间接测量得到电缆导芯温度、预防电缆接头故障,建立了电缆接头2阶和1阶暂态热路简化模型,提出了一种电缆接头导芯温度的反演算法,推导得出导体实时温度。同时,通过参数辨识对电缆接头进行在线监测并得到故障诊断结果。结果表明,建立的电缆接头2阶和1阶暂态热路模型可有效简化反演计算,进而通过电缆接头外皮和金属护套温度反推出导体温度,且所得反演结果与实测结果相符。此外,根据辨识参数相对正常运行状态时的变化情况,可判断出电缆接头是否存在故障隐患以及是何种故障。

To obtain the cable joint core temperature indirectly and prevent the fault of cable joint, we established the second- and first-order transient thermal circuit simplified models of cable joint, and proposed a retrieval algorithm to calculate the conductor temperature of cable joint; and then the conductor real-time temperature could be deduced. Meanwhile, the fault diagnosis results of cable joint could be obtained by online monitoring cable joints by using para- meter identification. The results show that the proposed first- and second-order model for transient thermal circuit inversion calculation can simplify the inversion computation; the conductor temperature derived from the temperatures of cable joint surface and metal sheath is consistent with the conductor temperature detected in actual measurement. Mean- while, it is also possible to determine whether fault risks will occur and which types of faults will ＂occur according to the variation Of identification parameter in relatively normal state.