电缆三时段热循环测试系统设计

Design of the Three-period Thermal Cycling Cable Test System

循环加热试验是电缆试验的核心,可直接检验电缆的护套材料耐温特性和电缆载流量值。常规循环加热设备多采用单机单测试形式,电气设备利用率低。为提高设备利用率,在有限时间内更好地完成多电缆样品测试,设计了一种分时复用的电缆热循环加热系统。该系统可在一个测试循环中完成三个时段内三组不同电缆的加热过程。系统采用Lab VIEW开发上位人机界面,以PLC作为核心控制单元,并采用了符号判别法进行温度控制,使系统具备更高的控制精度和控制稳定性。试验表明,该系统可有效提高电缆测试效率,节约多路测试设备成本,为新型电缆测试设备的开发提供了技术参考。

Cyclic heating test is the core of cable testing,which can directly test the temperature resistance properties of cable sheath material and the cable ampacity value. Conventional cyclic heating equipment is mostly in the form of standalone and for single test,thus the utilization of electric equipment is low. In order to improve utilization of equipment and better complete multiple samples testing in limited time, a time sharing multiplexing thermal cycling cable control system is designed, which can complete the heating process in a test cycle for three groups of different cables in three periods. In this system, Lab VIEW is used to develop the upper computer interface; PLC is the core control unit, and the symbol discrimination method is used to control temperature, so the system has higher control accuracy and control stability. The tests show that the system can effectively improve the efficiency of cable testing, save the cost of multichannel testing equipment, and provide technical reference for the development of new cable testing equipment.