我们所知道的太阳就是一个巨大的热辐射体，它不断向宇宙空间发出热辐射，在这些辐射中，除了我们能感受到的可见光线外，还有一种我们用肉眼看不见的“热线”，由于这种看不见“热线”的光谱位于红色可见光外侧，我们就称其为红外线。

在量子力学的理论体系中，任何物体在常温下都会因自身的分子和原子无规则的运动，产生热能。运动愈剧烈的分子和原子，其对外辐射出能量就愈大；反之，其辐射的能量就愈小。

红外热成像技术最早是应用于军事和科学探索领域，理论上认为，只要温度高于绝对零度（-273℃）的物体，都会辐射出红外线，工程师就利用这一特性，将物体发热部位产生的辐射功率信号，通过光电红外探测器转换成电信号，最终形成物体相对应的热像图。

二、在配网设备带电巡检工作的应用情况

电气设备进行不间断的巡视检查，即设备带电检测工作是目前电力部门极力提倡和推广的。由于电气不需要进行停电，从安全和经济上都能给供电部门带来极大的价值。巡视人员只要手持红外热成像仪，在保证安全距离的情况下，在设备运行状态就能对设备开展不停电的巡视检查，进一步提高供电可靠率，展示优质的供电服务。

在迎峰度夏保供电工作中，红外巡视工作要是设备维护的一个重点工作，利用夏季用电高峰期对可疑设备进行检测和复测，并建立完整的设备巡检的台帐记录，如制定相应的巡视标准化作业卡，记录好负荷电流情况、环境温度及测试部分，这样在发现异常时才能进行纵向的历史数据比较和横向的不同相别之间的比较。

三、电流的致热效应引起的接头发热缺陷分析

我们知道，当电流流过设备接头时，根据电阻损耗公式P=I^2·R，发热功率与电流平方成正比，如果回路中的电气接头，因接触不良或腐蚀氧化造成了接触电阻变大，当电流增大到一定程度（比如在用电高峰期，或转供电需要，一条馈线多带了另一条线路的负荷），这时的电阻热损耗就非常明显，巡视人员进行设备热成像巡视时就很容易发觉，因为其温升部位的图像相对于正常设备的热像图更加明显，很容易区别出来。而且电流致热引起的热缺陷，大数体现在隔离开关、接线板等电气连接部分。下面进行实例分析。

3.1 铝排接触面氧化引起的发热分析

例：对某造船厂10 kV配电房铝母线排的巡视检查中，发现A相母线的一处连接处温度高达111℃，当时的运行电流210A左右。由于该地区处于沿海位置，空气中含有大量的海盐成份，特别是对铝金属造成的腐蚀最为严重。在进行了停电处理时发现是一起施工质量引发的问题，发热的铝排加工面由于施工人员的疏漏，表面没有进行打磨和抗氧化处理。一般铝排加工面经钻孔后，表面可能会产生局部的变形，而经过削平打磨后可以增加接触面积。同时，铝金属在空气中极易自然氧化，表面很容易形成一层氧化铝，氧化铝对电气性能来说是绝缘的，是引起接触电阻增大的主要因素。而按照规定，环境腐蚀影响较严重的地区，打磨后的母线排表面还要涂抹上一层中性凡士林，以防止氧化反应的发生。

3.2 铜铝接头引起的发热分析

例：在一次检修人员处理套管接头发热缺陷时发现，是由两个不同材料的线夹直接接触造成的，分别是铜抱箍线夹和铝转角线夹组成。当铜、铝导体直接进行连接时，特别是在类似平潭海岛这样的运行环境中（因为海洋性气候中，空气或多或少会含有一定水份和盐份），这时的铜、铝接头就相当于浸泡在电解液内的一对电极，形成以铝为负极、铜为正极的电位差（相当于1.68 V原电池）。使铝产生电化腐蚀，造成铜、铝连接处的接触电阻不断增大。另外，由于铜、铝热膨胀系数相差很大，当流过大电流时，接头的温度升高还会引起铝本身的塑性变形，在运行中经多次冷热循环（电流的不断变化）后，会使接触点处产生间隙而影响接触，即增大了接触电阻，运行中就会引起温度升高并加剧，这是一个恶性循环的过程。所以电气设备的接头加工，在一般情况下禁止将铜和铝接头进行直接连接，否则应该采取将铜接头搪锡或采取铜铝过渡片等方法。

四、红外热成像巡检工作存在的问题探讨

对于密封在金属柜子里面的电气设备，我们巡视人员在现场检测中发现，红外辐射的穿透能力是很弱的，基本上不能穿透设备外壳或玻璃观察窗的，所以对各种配电开关柜的玻璃观察窗进行热成像巡视时，开关柜内的设备发热缺陷就无法及时有效地发现，如果在设备运行下打开柜门巡视，又存在一定的安全风险，而有的设备由于设计了机械五防锁，在设备运行状态下是无法打开后柜门的，这也是进行红外线热成像仪巡检工作的一个局限性。我们只有通过平时的巡视，不断地积累经验和数据，当然，这个问题也可以作为今后课题研究的一个方向。

五、测试中的安全措施及注意事项

1. 电流效应的热缺陷是与电流大小有着直接关系的，有的设备接头已经氧化腐蚀很严重，但是如果没有电流通过，或通过的电流很小，不足以引起发热，这样缺陷变成无法暴露出来。同时，检测环境也应选择在傍晚、夜间或背景温度较低的情况下进行，这样做可以最大化地减少环境温度对测量的影响。测温时间一般控制为半个小时左右，特别是在农村，接下来时段负荷降得比较明显，电流效应的热缺陷就不容易暴露出来，如果在半个小时内测不完，宁可选择下个工作日测试。
2. 成像部位主要选择设备的接头，即连接处，这些部位是最容易引起螺栓松动和接触面的氧化的地方。
3. 对巡视的档案要进行及时有效的记录，要录入GPMS系统，形成闭环管理。缺陷记录是检修人员制定检修计划的依据，也是工程质量全过程管理的依据。如有的新设备在刚投运时是没有问题，但是运行了一段时间后，在保质期内出现了问题，经查明是施工质量引起的，就要追究施工人员的责任。

The goal of the infrared online monitoring system is to monitor the flow of the valve hall. The whole valve hall is divided into four areas: extremely low I, extremely low II, extremely high I and extremely high II. There are 6 flow changers in each area, a total of 24 flow changers.

The infrared on-line monitoring system is distributed in 4 areas, with 7 monitoring devices laid in each area, a total of 28 monitoring devices. Through the high-precision pan tilt and rail car control system, the monitoring of all converter flow can be realized.

Infrared application

1. Composition of infrared online monitoring system

The infrared online monitoring system mainly consists of:

"Field monitoring equipment"

"Communication network"

"Infrared monitoring platform"

"Infrared online monitoring system client" consists of four parts.

2. On site monitoring equipment

The on-site monitoring equipment is the eye of the whole system,

Equipped with temperature measuring infrared thermal imager and high-definition visible light,

Equipped with high-precision PTZ and railcar control system,

The valve hall can be fully covered without dead angle.

3. Infrared online monitoring system client

The client of the infrared online monitoring system is composed of system menu, equipment layout, equipment list, real-time temperature, temperature measurement record, high temperature alarm, cruise status, shortcut menu and other modules, which visually displays the current operation status of the whole system, including valve hall information, equipment information, temperature measurement information, alarm information, cruise information, etc.

Case analysis

Technical advantages

1. Fully distributed network management, full network digital monitoring

It can be compatible with other monitoring systems, such as the real-time collection of environmental information such as temperature, humidity and water immersion in the station.

2. The front-end infrared thermal imager has a high degree of integration, and the equipment can operate independently. The plug and play front-end infrared thermal imager integrates the infrared thermal imager, visible light network camera and streaming media server. There is no need to install a hard disk video recorder separately, which greatly simplifies the equipment installation and reduces the failure points.
3. Powerful temperature analysis function

The temperature measurement shall be corrected according to the ambient temperature, the emissivity of the object and the distance to ensure the accuracy of the temperature measurement.

4. Cruise control

The system has the function of automatic cruise, and can capture or record pictures for each cruise position. Conduct temperature analysis at the cruise position. If there is abnormal temperature, the equipment will actively alarm and notify the monitoring client.

5. Equipment alarm

When the detected target object exceeds the set threshold, send temperature alarm information to the client. When the equipment has various faults or network faults, corresponding alarms will also be generated to facilitate the positioning of the problem.

Applicable Machine

Ubiquitous power Internet of things

The ubiquitous power Internet of things is to focus on all links of the power system, make full use of modern information technology and advanced communication technology such as mobile Internet and artificial intelligence, and realize the interconnection of everything and human-computer interaction in all links of the power system. It is an intelligent service system with the characteristics of comprehensive state perception, efficient information processing, convenient and flexible application, including four layers of structure: perception layer, network layer, platform layer, and application layer.

UHV Substation

As a landmark project for the large-scale application of UHV AC transmission technology in the world, 1000 kV high-voltage substations can meet more than 1/3 of Shanghai's electricity demand under full load transmission. They are super large hub substations with complete voltage levels in China.

As a pilot unit of State Grid Corporation of China for the construction of ubiquitous power Internet of things, the operation platform developed by a domestic UHV substation has been put into trial operation recently. Wuhan huajingkang Photoelectric Technology Co., Ltd., as the designated partner of the infrared thermal imager equipment of the project, embeds the infrared thermal imaging products into the whole service system, and customizes the corresponding infrared detection schemes for different application scenarios.

Infrared IOT monitoring

For all key parts such as transformers, bushings, clamps, etc., Wuhan huajingkang Photoelectric Technology Co., Ltd. has fixed multiple on-line thermal imagers for fixed-point continuous monitoring, and added multiple ROI temperature measurement areas to meet the requirements of reliability and real-time, while ensuring accurate temperature measurement in high temperature and other harsh environments.

For the transformer bodies of multiple main transformer circuits and the voltage transformers connected with them, high-resolution 640 are arranged respectively × 480 double optical pan tilt, set preset positions for automatic inspection, covering all transformers and voltage transformers connected to them on the opposite side.

For the wind control box equipped with the main transformer, due to the many internal devices in the control cabinet, the narrow space, and the large area that needs to be monitored, each control cabinet is installed and deployed with three huajingkang photoelectric s300b infrared thermal imagers, which adopt a large field of view lens and are equipped with a visible light camera and LED lighting, covering the entire monitoring area.

Cloud platform

Hua Jingkang not only provides omni-directional thermal imager monitoring for ubiquitous power Internet of things, but also independently develops a cloud platform. The thermal imager can access the network through wireless WiFi, wired and mobile cellular methods, and summarize and transmit the data to the cloud platform for storage and management.

Cloud big data and machine learning algorithm are combined to comprehensively analyze multi-dimensional information, establish an expert system based on multivariable analysis model, and carry out intelligent fault diagnosis, aging prediction, defect warning, etc. for the operation of power system.

Using the cloud monitoring Internet of things system, the new power operation and maintenance personnel can check the equipment operation and temperature status in all substations, transmission towers, distribution rooms and other power facilities distributed within a radius of hundreds of kilometers by opening the app software on their mobile phones or intelligent terminals, and make automatic diagnosis by using advanced technical means such as big data and machine learning, which greatly reduces or eliminates the dependence on personnel and quickly finds out the location of suspected hidden dangers, Reduce troubleshooting time.

Based on its long-term technical accumulation in the power industry, combined with the advanced technologies of "big cloud mobile intelligence", Hua Jingkang has helped build the "ubiquitous power Internet of things". With widely distributed intelligent sensors as the data basis, network system as the context, and data processing and intelligent algorithm on the cloud platform as the core, it comprehensively monitors the operation status of all parts of the power system, and improves the operation and maintenance efficiency of the power system, Ensure the safe and stable operation of the system.

Applicable Machine