INNO fibre optic temperature sensors ,temperature monitoring systems.
The importance of temperature monitoring system for electrical equipment in substations
In the power system, the temperature change of power equipment is a very important indicator, which is related to whether the power equipment can operate safely and stably. During the operation of the substation, the electrical contacts of the equipment may increase in contact resistance due to equipment manufacturing, electric shock oxidation, arc impact, and other reasons, causing their temperature to rise. When the temperature rises to a certain level, the mechanical and electrical strength of the equipment will decrease, and in severe cases, it can lead to short circuits in electrical equipment, and even damage the equipment, seriously threatening the safe and stable operation of the power grid. Real time monitoring of the temperature of electrical equipment can help duty personnel detect problems as early as possible, eliminate hidden dangers, and ensure the safe operation of the power system.
Traditional temperature measurement methods in substations
The original infrared monitoring method of the substation equipment mainly used portable infrared thermometers for manual inspection by operators. The stored thermal images were often analyzed and diagnosed on the background PC, which can only be intermittent analysis and control. It cannot monitor the thermal distribution field in real time and diagnose the fault nature of the thermal images. Due to the inconvenience in use and the defects in the methods, it is difficult to meet the growing requirements of the power system for real-time performance, economy, safety, reliability, and ease of use, which often leads to monitoring delays and significant property losses.
The reasons for the temperature rise of the switchgear in the power supply system substation
The safe and reliable dispatch operation of the power supply and distribution system plays a very important role in ensuring the sustainable development of the national economy and the stable economic electricity consumption of users. The staff of power supply and distribution enterprises must take various technical measures to improve the safety, stability, and energy-saving economy of the power grid system operation. The switchgear is an important carrier for power resource allocation and scheduling in the substation system, especially the application of drawer type switchgear such as KYN28A-12, GCS, MNS, etc. in substations greatly improves the convenience of operation and maintenance. However, due to the complex thermal and magnetic environment during the daily operation of the dynamic and static contacts of the switchgear, loose contacts, poor contact of switch springs, aging of switch spring performance, inadequate maintenance measures leading to dust entering and forming conductive flashover gaps, etc., the temperature of the switch contacts continues to rise, the operating environment deteriorates, and the defects gradually deteriorate into faults or accidents, seriously affecting the safety and reliability of substation power supply. Therefore, analyzing the reasons for the actual temperature rise and heating of the substation switchgear, and forming targeted prevention and treatment measures to ensure the safe and reliable, energy-saving, efficient and stable operation of the switchgear, has very important engineering practical application research significance for improving the reliability of enterprise power supply and electricity safety.
What are the dangers of heating the contacts of drawer type switchgear in substations
The drawer type switchgear in the substation is an excellent product obtained through the improvement of the switch contact structure on the basis of the conventional GGD type regulated switchgear. As a direct hub between the power supply and distribution system and power users in the substation, it is the core electrical control switch for energy conversion and distribution. Whether the internal switch components have a high quality level and can operate safely and reliably is an important guarantee for energy conversion and distribution. During the maintenance and repair process of the substation, temperature rise tests are mainly conducted to verify the electrical and mechanical performance of the relevant switch equipment inside the switchgear. The moving contact of the drawer type switchgear belongs to the movable contact part, and its maximum allowable temperature rise should not exceed 40C. When the temperature exceeds 40C, it will cause the switchgear to enter a thermal dead cycle, seriously reducing the overall electrical and mechanical performance of the switchgear. The heating and temperature rise fault of the substation switchgear contacts is not an instantaneous fault, but a vicious cycle of heating, aging, further heating, and further aging. The temperature on the surface of the contact does not rise. When the surface temperature exceeds the rated heat resistance level of the insulation sleeve or current (voltage) transformer inside the switchgear, it can cause damage to the insulation of the insulation sleeve or transformer, and even lead to accidents such as transformer explosion.
1. The handling time for contact heating faults is relatively long
The heating fault of the contact can affect the safety and reliability of the operation of the switchgear. In the event of a circuit breaker failure or extensive damage to ancillary equipment, it is usually necessary to return to the factory for comprehensive replacement. During the process of returning to the factory for maintenance, the required time is relatively long, which greatly prolongs the fault handling time of the switchgear and seriously affects the safety and reliability of the substation power supply.
2. Bringing economic losses to power supply and consumption enterprises
Due to temperature rise faults or accidents, drawer type switchgear in substations can cause power outages, which can affect the normal power supply and service level of power supply enterprises; On the other hand, it will affect the normal electricity consumption of electricity consuming enterprises, especially for some precision machining or production enterprises. Sudden interruption of electricity can seriously affect normal production, resulting in substandard and residual products, which will bring significant economic losses to power supply and electricity consuming enterprises.
Common causes of contact heating in drawer type switchgear in substations
1. Switch capacity design does not match daily operation
In the process of optimizing the selection and design of switchgear, due to insufficient consideration of the load characteristics of the power supply and distribution system and the balance of energy supply and demand, there is a mismatch between the selected switchgear and actual operation, resulting in too much excess capacity of switchgear and causing a lot of waste; However, some switchgear devices do not match their actual power supply capacity, resulting in a continuous increase in contact temperature under the strong thermal current during operation, leading to serious temperature rise problems in some areas.
2. There are hidden dangers in the quality of installation and debugging
Due to some reasons, some switchgear does not strictly follow the design or relevant specifications for quality control during installation and debugging, resulting in installation quality hazards. This leads to poor connection performance between some electrical components in the switchgear, resulting in conductive gaps, etc. In the later operation process, the hazards continue to evolve into faults or accidents, and the temperature rise effect continues to strengthen, seriously affecting the safe and stable, energy-saving and economic operation of the switchgear.
Install a fiber optic online temperature monitoring device inside the switchgear to collect and analyze the temperature, mechanical characteristics, partial discharge, current, voltage and other characteristic parameters of switch equipment such as isolation switches, load switches, and circuit breakers online, facilitating the timely understanding of the operating conditions of the switch equipment by substation operators. When the actual temperature of the switchgear contacts exceeds the pre-set limit value of the system, the fiber optic monitoring device can be controlled by the upper computer and other forms to prompt operators to timely inspect and test the operating conditions of relevant components on site, eliminate potential safety hazards in a timely manner, and prevent the hazards from further expanding into faults or accidents.
The safe and stable operation of substation switchgear is an important guarantee for the reliable and effective allocation and scheduling of electrical resources in the power supply and distribution system. By using reasonable daily maintenance methods, preventive testing, and configuring an online temperature rise monitoring system, the reliability, stability, and accuracy of switchgear actions can be greatly improved, ensuring that the power supply and consumption of power supply enterprises have high safety, reliability, and energy efficiency.