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You may also have encountered the following problems!

SF6 gas density relay is mainly used to monitor and control the density of SF6 gas in sealed containers. Generally used in high voltage switches (GIS/PCB), medium voltage switches (CGIS), gas insulated equipment, high voltage cables (GIL), gas-filled transformers and transformers (CT/PT). It is actually a pressure gauge or pressure switch with electrical contacts and temperature compensation, and its classification mainly includes:

According to the difference of compensation principle, it is divided into two types: compensation chip type and relative cavity type;
According to the difference in appearance, it is divided into two types: pointer type and non-pointer type;
According to the difference of anti-vibration methods, it is divided into: oil-free type and oil-filled type;
According to the difference of pressure test methods, it is divided into two types: relative pressure type and absolute pressure type.

Because the SF6 gas density relay, like other pressure gauges, will have a certain drift in its alarm and blocking values ​​after a period of use; in addition, because the contact action of the density relay is not frequent, the contact action may be insensitive or invalid. If it is not checked, there is a safety hazard. There are problems with the quality of density relays for the following reasons:

The anti-vibration performance itself is not good enough. After the strong shock of the switch opening and closing, the pointer is stuck, the contact is permanently invalid (doesn't move or keeps moving), and the deviation exceeds the standard.
Due to oil leakage, its anti-vibration performance is reduced. After the switch is strongly impacted by opening and closing, faults such as pointer stuck, permanent contact failure (no action or constant action), and deviation exceeding the standard occur.
Because the contacts of the commonly used relays are magnetic-assisted electrical contacts, the contact closure force itself is small, and the time is slightly longer. Once the contacts are oxidized, the contacts will be blocked or the contact will be unreliable. For the oil-free type, the magnetically assisted electrical contacts are exposed to the air and are very susceptible to oxidation or accumulation of dust.
Its contacts are prone to poor contact or no connection; for oil-filled types, although the magnetic-assisted electrical contacts are immersed in silicone oil, the contact performance will decrease after a long time and several operations, and the oil film has an insulating effect. Its contacts will also have poor contact or no connection.

Due to its own manufacturing quality problems, the temperature compensation is inaccurate, and the error is seriously large (over-compensation or under-compensation).
Due to insufficient aging or material problems, it will drift over a long period of time, and the accuracy will be seriously large (the stress is not eliminated).
There is a failure (never action) at low temperatures due to a design flaw.
Due to design flaws, the action and display values ​​are severely degraded at high temperatures.
For the relative cavity density relay, due to internal or external reasons, the standard cavity will leak air, and there will be a large error in the action value or failure.
Due to severe vibration during transportation, the relay will fail and the accuracy will deteriorate.
Due to the quality of the components, a slightly longer time may cause the relay to fail and the accuracy to deteriorate.
Because the housing vent is not loosened, or the housing is sealed, the internal pressure of the housing changes, which changes the accuracy.
Due to the erosion of rain or corrosive gas, the relay will fail and the accuracy will deteriorate.
It will also affect the use due to improper use (poor installation location).
Due to process problems, the density relay relay will fail, or the accuracy will deteriorate.
In order to reduce costs, switch factories or relays choose inferior products or components.
Electrical properties: Insulation issues.
sealing performance.

WINFOSS and Italian EMD and Swiss TRAFAG are long-term strategic partners. In Europe, WINFOSS has provided verification and customization services for SF6 density relays for as many as 3,000 substations in more than 30 countries. WINFOSS aims to provide power users with density meters, verification services, engineering transformation and spare parts, etc. A full range of solutions. And fully consider the technical parameters and requirements of China's power market to meet the different needs of different users.

Verification basis: The former Guodian Corporation attached great importance to the regular inspection of SF6 gas density relays, and formulated DL/T596-1996 "Procedures for Preventive Tests of Electric Power Equipment" and "Twenty-Five Key Requirements for Preventing Electric Power Production Accidents" by the National Energy Administration Item 13.1.6 of "Prevention of GIS and Switchgear Accidents" in Item 13 of the Interpretation and Compilation, and Item 12 of the revised edition of the State Grid Corporation's Eighteen Major Anti-Accident Measures for Power Grids of the State Grid Corporation of China, "Prevention of GIS and Switchgear Accidents" ” The connection method between the sulfur hexafluoride density relay and the switchgear body in Item 12.1.1.6 should meet the requirements of not disassembling the verification density relay.

16.10 To give full play to the role of SF6 gas quality supervision and management, fresh gas management, gas monitoring of operating equipment and abnormal situation analysis should be done well. Monitoring should include regular calibration of SF6 pressure gauges and density relays.

And a summary of the actual situation of verification in various places in recent years is as follows:

The report after testing by the Qinghai Pilot Test Institute shows that the failure rate of SF6 density monitoring devices used in domestic switches that have been in operation for more than 3 years exceeds 30%, which has serious potential safety hazards and frequent safety accidents.
The latest information from the Qinghai Pilot Test Institute: In June 2007, the institute checked a batch of density relays produced by a domestic manufacturer, and the pass rate was surprisingly low (only 3 of 51 passed).
According to the 67th issue of the Technical Supervision Briefing (Thermal Engineering) of Fujian Electric Power Company: 94 were checked and 23 failed, with a failure rate of 24.4%.
"High Voltage Electrical Appliances" reported: A 35KV switch in Huaibei Bureau of Anhui Province exploded due to the failure of the density relay and the opening of the switch due to air leakage.
In 2006, a 35KV switch in Qujing, Yunnan Province exploded due to the failure of the density relay and air leakage.

What problems can we solve?
 

1. Provide SF6 density relay calibrator: fully automatic intelligent SF6 gas density relay calibrator with the help of MAX5H core technology. The calibrator adopts an embedded microprocessor and a fully enclosed SF6 gas circulation system, which can perform performance verification on various SF6 gas density relays, normal temperature pressure gauges, and P20 pressure gauges. This calibrator can be used for the production, maintenance and monitoring of SF6 gas products, especially suitable for power systems, and provides convenience for the production and safe operation of SF6 density relays. It can support both online and offline laboratory calibration methods, and adopts self-provided high-energy
Two energy options, battery and external charging interface, make the user's field application more flexible.

2. Technical transformation services for reserved verification interfaces: After investigation, SF6 electrical equipment without reserved verification interfaces is also commonly found in China’s power market (especially the Yunnan, Guizhou and Guizhou provinces of China Southern Power Grid and Sichuan, Chongqing, Shaanxi and Sichuan) of the State Grid. new and other local areas). When this kind of equipment regularly calibrates the density relay, it is necessary to power off the involved lines, and then remove the density relay from the connection of the three-way valve, and then carry out the on-site field or bring it back to the laboratory for calibration on the calibration instrument. After the calibration is completed, install it in the original position again, and then use the SF6 gas leak detector to check the installation position for leaks.

This operation has the following disadvantages:Power outages on the lines, and the possible outages for a long time, will result in certain economic losses;
It is time-consuming to disassemble and install the density relay, and it is easy to cause certain damage to the sealing surface and rubber ring of the connection during the operation, which increases the risk of air leakage;
Install the calibration valve without dismantling the meter: the calibration valve is generally connected to the air supply port of the original three-way valve. In the subsequent regular calibration process, the calibration can be realized without power failure and disassembly of the density relay, which greatly saves time. , human and financial resources.
3. Provide SF6 density relay verification service: provide users with real-time, on-site and real-time SF6 density relay professional verification services. Users who cooperate with WINFOSS can trigger the service on a regular or real-time basis, and the professional service engineers of WINFOSS will carry out the verification on the spot. test work. The verification report and on-site marking will be issued by WINFOSS engineers to provide the most powerful decision-making basis for user maintenance.
4. Spare parts supply of SF6 density relays (including the customization of sealed pot density relays): Due to the years of use of SF6 density relays, especially a considerable number of density relays are still operating in outdoor environments. Affected by various factors such as climate environment, material aging or equipment maintenance, if defective SF6 density relays are found after verification, WINFOSS will provide users with ample spare parts support. It can cover the replacement or customized application of supporting instruments on ABB, SIEMENS, ALSTOM, AREVA, SETOM, HOLLEM, AKD, TOSHIBA and various high-voltage equipment in China.
5. SF6 density relay rain cover customization and replacement: Due to the aging and damage of the rain cover due to the outdoor environment and maintenance, WINFOSS provides users with related accessories in the process of density relay verification, replacement and technical transformation. Provide users with more comprehensive services and value.

Why choose WINFOSS?

Professional Value: 30000
For more than 20 years, WINFOSS has always stood at the forefront of the world's professional gas detection technology to promote the development of power intelligence and safety management, providing customers with a large number of high-quality projects and services. So far, WINFOSS services have provided more than 30,000 customers at home and abroad. service support. Professional operation achieves the optimal cost, professional advantages provide the most powerful guarantee, and professional management continuously creates value for customers.

Technical value: 20+40
Relying on the technical precipitation and development of WINFOSS for more than 20 years, and the technical advantages and experience accumulation of R&D, design and manufacturing of Swiss Electric for more than 40 years, it has formed the most powerful professional technical competitiveness of WINFOSS services. "Concentration, profundity, excellence", WINFOSS service attaches great importance to the training and growth of the service engineer echelon, and regularly conducts professional skills training and skills competition activities, so that the technical quality of the WINFOSS service team will always be at the forefront of the industry.

Network value: 100+300
WINFOSS service is Switzerland's largest power testing service provider with the most complete service network and the strongest service technology strength. It has 100 service outlets and 300 service engineers. Service "people-oriented". The headquarters of WINFOSS service company has gathered abundant human resources and technical force, and has professional product service engineers, system design engineers, software development engineers, system maintenance engineers, technical training lecturers, etc. At the same time, each service network brings together a variety of products, experienced and well-trained professional service personnel, strong technical force, and unified training, unified service specifications, unified management, and unified assessment, so that professionals can be professionally employed and provide customers with high-quality services. Quality service.

Resource value: 2000＋3000
WINFOSS service continues to build a service hardware resource platform with comprehensive service tools and equipment, which better guarantees the professionalism and accuracy of on-site debugging and maintenance services from tangible equipment. WINFOSS service relies on WINFOSS spare parts service outlets around the world to ensure that users are provided with reliable quality dedicated or original spare parts. The WINFOSS Service Headquarters has a spare parts warehouse with spare parts valued at more than 30 million yuan. The spare parts stock is sufficient. Each service network has different levels of spare parts storage, so as to provide customers with the first-time main spare parts response service.

Caring Value: 7×24
"Mobility, speed and quality" are the professional qualities that WINFOSS service has upheld and formed for a long time. WINFOSS service engineers provide fast expert-level support services for your power detection system around the clock, telephone support at the first time, 7×24 hours of uninterrupted whole process Service care, web-based remote diagnosis and maintenance and perfect CRM (customer service management system), maximally close to customers, and more meticulously meet customers' real-time work needs.

WINFOSS China: 3+7
WINFOSS came to China, aiming to provide comprehensive power SF6 testing and supporting professional services for China Electric Power. It will be dedicated to the sales of hardware products within 3 years, and will build a comprehensive service network and team within 7 years to suit China localization needs. Compared with Northern Europe, China has more extensive power equipment, more complex climate and environment, more severe aging of equipment, and more uneven types and quality of equipment. Therefore, in China, WINFOSS has a more arduous mission to complete, and can provide more abundant, more comprehensive and more professional value for Chinese power users.