wireless fiber optic temperature sensor Practical scheme for temperature measurement of high-voltage switch contacts and busbars

Cảm biến nhiệt độ sợi quang, Hệ thống giám sát thông minh, Nhà sản xuất cáp quang phân phối tại Trung Quốc

With the progress of society, the voltage level of the power grid is constantly improving, and the requirements for the safety and reliability of power supply for the use of electrical equipment are also increasing. With the increase of electricity demand, it will lead to an increase in power supply load and aging of power supply equipment. During long-term operation, various electrical equipment in substations are prone to overheating due to excessive contact resistance or insulation aging. This potential hazard directly affects the normal operation of electrical equipment, and in severe cases, it can even cause major accidents, leading to personal injury and economic losses.

High voltage isolation switches are the most widely used and widely used high-voltage switchgear equipment in power grid operation. Their existence ensures the personal safety of maintenance personnel. They operate in high voltage and high current environments, and the temperature rise of their contacts directly affects the reliability of power supply. Tuy nhiên, during the operation of the power grid, factors such as unclean contact surfaces of electrical equipment, burning of contacts, and mechanical deformation and looseness can all lead to deterioration of contact conditions, increasing contact resistance, causing higher temperature at the contact points, accelerating oxidation of the contact surfaces, and ultimately causing local welding or arc formation at loose contact deformation points, ultimately leading to major electrical accidents such as damage to electrical equipment and even power outages. Do đó, real-time online monitoring of contact temperature is of great significance in the operation of electrical equipment in substations. Hơn nữa, for operating electrical equipment, temperature is a very important parameter, which can directly determine whether an electrical equipment is operating normally through temperature information. In the power system, high-voltage switchgear and cable branch boxes in power plants and substations are important equipment to ensure stable and reliable power supply.

The existing electrical equipment has increasingly high requirements for power supply reliability. Under high voltage and high current conditions, the working reliability of high-voltage switchgear is closely related to the temperature rise of isolation switch contacts. During the operation of the power grid, mechanical vibration, contact erosion, and other reasons can worsen contact conditions, increase contact resistance, cause an increase in contact point temperature, exacerbate contact surface oxidation, and lead to local welding or arc discharge at loose contact points, ultimately causing damage to electrical equipment, mất điện, or major accidents such as fires. This type of contact overheating fault accident is not only due to the quality problem of the high-voltage cabinet switch itself, but more importantly, due to the lack of effective monitoring methods for the temperature rise of the isolation switch contacts at present. One of the reasons is that there is exposed high voltage inside the cabinet, and conventional temperature measurement methods cannot be used; Thứ hai, the online real-time temperature measurement system for switchgear currently used in the power system is characterized by cumbersome installation, heavy wiring, inconvenient maintenance, and high cost. Factors such as aging of contacts can easily lead to an increase in contact resistance, which may result in serious accidents such as excessive heating or even burning of the contacts.

The traditional temperature measurement methods for switchgear include
(1) Using an infrared thermometer. The infrared thermometer is equipped with a data interface, which can transmit real-time temperature data to the background for display and alarm, and can also be indicated locally. The advantage of this scheme is high measurement accuracy; The disadvantage is that the price is relatively expensive, requiring power cord pulling, close range visual installation, and power outage installation.
(2) Manual inspection is adopted. The manual inspection method for temperature measurement of switchgear has many drawbacks, such as the inability to accurately measure temperature and the consumption of a large amount of manpower and material resources, which is very costly,
(3) Using a wireless thermometer. A low-power temperature measuring instrument developed in China in recent years using low-power microcontroller, temperature sensor, and wireless communication chip technology, with a built-in battery that can operate for 2-3 years. The advantage of this plan is its low price; The disadvantage is that the battery has a short service life, high maintenance costs, and requires power outage installation and disassembly.

The most advanced temperature measurement solution now is to use fluorescent fiber optic temperature measurement in switchgear. The main technical advantages of fluorescent fiber optic temperature sensors and temperature measurement devices are:

Suitable for strong electromagnetic, radio frequency, and microwave temperature measurement environments;

The probe has good interchangeability and repeatability;

Temperature measurement range light, high measurement accuracy;

Excellent reliability and stability;

Simple structure and long service life;