2. 为何电缆需要用分布式光纤测温？ 2. Why Use Distributed Fiber Optic Temperature Sensing (DTS) for Power Cables?

电缆用分布式光纤测温（DTS），是为了全线无死角测温、精准定位过热点、抗电磁干扰、长距离免维护、提前预警火灾 / 击穿——传统点式测温根本做不到。 Distributed Temperature Sensing (DTS) using fiber optics is employed in power cables to achieve full-line dead-zone-free temperature monitoring, precise hotspot localization, electromagnetic interference immunity, long-distance maintenance-free operation, and early warning for fire or insulation breakdown—capabilities that traditional point-type temperature measurement simply cannot achieve.

一、电缆最怕"看不见的局部过热" 1. Cables' Greatest Threat: Invisible Local Overheating

电缆故障 80% 以上和温度有关： Over 80% of cable failures are temperature-related:

• 过载 → 导体升温 → 绝缘加速老化 Overloading → conductor temperature rise → accelerated insulation aging
• 接头压接不良 → 接触电阻大 → 局部高温（最常见起火点） Poor joint crimping → high contact resistance → localized overheating (the most common fire ignition point)
• 绝缘老化 / 受潮 → 局部损耗变大 → 热点 Aged or moisture-damaged insulation → increased local losses → hotspots
• 隧道 / 沟内堆积、通风差 → 环境高温叠加 Cable accumulation in tunnels/trenches with poor ventilation → compounded by high ambient temperatures

核心特点：早期只在某一小段发热，整体温度正常，点式传感器根本碰不到。 Key characteristic: In the early stages, heating is localized to a very small segment while overall temperatures remain normal—point-type sensors simply cannot detect it.

二、DTS 五大不可替代的核心优势（为什么必须用它） 2. Five Irreplaceable Core Advantages of DTS (Why It Is Essential)

1）真正"分布式"：整根电缆每米都在测温 (1) True Distributed Sensing: Temperature Measured at Every Meter Along the Entire Cable

• 单根光纤 = 无数个连续温度传感器 A single optical fiber = countless continuous temperature sensors
• 空间分辨率：0.2 ~ 0.5 米，定位精度：高端可达 ±0.05 m Spatial resolution: 0.2–0.5 m; localization accuracy: up to ±0.05 m on high-end systems
• 传统方式：热电偶 / 热敏电阻只能"选几个点"，漏检率极高 Traditional approach: thermocouples / thermistors can only "sample a few points," with an extremely high miss rate

2）长距离、全覆盖（高压 / 隧道 / 海缆必备） (2) Long-Distance Full Coverage (Essential for High-Voltage, Tunnels, Submarine Cables)

• 单通道可达 10–20 km，多通道可上百公里 Up to 10–20 km per channel; hundreds of kilometers with multi-channel systems
• 隧道、管廊、地埋、桥架、风电场 / 光伏直流电缆都能全线监测 Full-line monitoring for tunnels, utility corridors, buried cables, cable trays, wind farms, and PV DC cables

3）强电磁环境下唯一可靠的测温方式 (3) The Only Reliable Temperature Measurement Method in High-EMI Environments

• 光纤全介质、无源、不导电、不受高压 / 强磁场干扰 Fiber is all-dielectric, passive, and non-conductive, immune to high-voltage and strong magnetic field interference
• 电缆 / 母线 / 开关柜附近，电子传感器容易漂移、失灵、甚至被击穿 Electronic sensors near cables, busbars, or switchgear are prone to drift, malfunction, or even breakdown

4）寿命长、免维护、本质安全 (4) Long Service Life, Maintenance-Free, Intrinsically Safe

• 光纤寿命 20–30 年，和电缆同寿命 Fiber optic service life of 20–30 years, matching cable service life
• 传感器端不用供电，只在主机端供电 No power required at the sensor end—only the host unit needs power
• 隧道 / 沟内潮湿、腐蚀、易燃易爆环境都安全 Safe in humid, corrosive, and explosive environments found in tunnels and cable trenches

5）早期预警 + 精确定位 + 趋势分析 (5) Early Warning + Precise Localization + Trend Analysis

• 秒级刷新，温度突变立刻报警（火灾前兆） Second-level refresh rates with immediate alarm on temperature spikes (a precursor to fire)
• 直接给出：哪一公里、哪一米过热，运维直奔现场，不用全线排查 Pinpoint reporting of exactly which kilometer and which meter is overheating—operation teams go straight to the site, no full-line inspection needed
• 长期数据：评估老化、优化载流量、做寿命预测 Historical data: assess aging, optimize ampacity, and perform life prediction