35KV power cable
1. Brief Introduction of XLPE Insulated Power Cable
Since the 1960s, XLPE cables have developed rapidly in China, and have replaced oil-immersed paper insulated power cables and XLPE cables. Because of their excellent electrical performance, good thermal overload characteristics, high voltage level, large transmission capacity, light weight and no drop restriction, XLPE cables can be laid vertically and electrically. Cable installation and operation and maintenance are convenient, so it is not only widely used in the low and medium voltage range of 35 kV and below.
2. Product Standards
3.1 The maximum rated temperature of cable conductor is 90 C.
3.2 The highest temperature of cable conductor is not more than 250 C when short circuit occurs (the longest duration is not more than 5s).
4. Regulations on rated voltage grade, type and specification of cross-linked cables
4.1 Selection of rated voltage of cable:
The cable quota voltage should be suitable for the system voltage and operation condition of the cable. It is expressed by U0/U (Um) and is all valid in units of kV.
U0 - rated voltage between conductor and shield or metal sleeve for cable design
U-rated power frequency voltage between conductors for cable design
Um - maximum voltage of the equipment (maximum value of the maximum voltage of the system using the equipment)
5. The rated voltage of phase system cables is as specified in Table 1.
|Category 1 Cable||Category 2 Cables|
Note: U0 can be classified into two categories according to the duration of grounding fault.
The first type of cable is used for the system with single-phase ground fault time not more than 1min, and also for the system with maximum time not more than 8h and annual cumulative time not more than 125h.
Category 2 cables are used in systems with longer grounding fault time. Category 2 cables can also be used when the insulation performance of cables is required to be high.