Control cable distributed capacitance parameter testing

As prescribed in article 141715 of the SGC 18 counter measures, for the long cable tripping circuit must be done to prevent the length of cable capacitance influence and the measures to prevent exports relay maloperation. So for the protection of control cable to use count how many meters long cable, hundreds of meters long cable capacitance is how much, cable manufacturers generally do not provide this parameter. For this, firstly analyzes the different cable conductor space layout structure and the relationship between the distributed capacitance, formulated the equivalent distributed capacitance circuit, and then according to the equivalent circuit of the measured part of the distributed capacitance parameter of the cable, on this basis, according to the equivalent circuit software simulation mathematical model is established, simulated proofreading, verified the validity and the feasibility of testing method, the equivalent circuit, in turn, is measured by the method of the distributed capacitance parameter of the control cable for a variety of protection, the statistical regularity of [123].
The basic structure of control cable, is generally composed of conductors, insulating layer, around the bag, filling material, shielding layer and sheath.Due to the applications of control cable is different, the material of each part is different, PVC insulated PVC sheathed control cable, it is suitable for laying indoors, in cable trench, pipelines and other fixed places, and is suitable for the requirements of the flame retardant PVC insulated flame-retardant control cable, etc.
According to the control cable shielding effect to differentiate, can be divided into KVV type copper core PVC insulated PVC sheathed control cable, KVVP type PVC insulated PVC sheathed braiding screened cable, KVVP2 type PVC insulated PVC sheathed copper tape screened cable, KVV22 type PVC insulated PVC sheathed steel tape armoured shield cable, etc.
Control cable structure
Some general protection with control cable in the majority with 2,4,7,8,10,12,14 core, wire cross-sectional area 1115215, 4 and 6 was common. Current voltage circuit was 4 * 4 commonly used with shielding control cable, control circuit used 7 x 215 was and 7 x 115 was shielded control cable.