Described.properties dc cable developers ideas to the development of special filler secret ~
Space charge this difficulty
Power development corporation in 1979 completed the connection of Hokkaido and the state's north the first submarine cable and putting-in-service proactively grid line.But then, laying cable in oil insulated cable, consider to add and update, people want to use more environmental protection described.properties of dc cable.Is the power of promoting development with sumitomo electric co., LTD (then) Mr Asano light, he recalls: "from sumitomo electric development team unusual YiLiZhong, I felt the enthusiasm 'resolutely go the whole hog."
"The biggest difficulty is how to suppress space charge.Charge is a kind of invisible, object of power.And when applied dc voltage, the accumulation of charge in insulators is space charge.As a result of the existence of space charge, dielectric cannot give full play to the performance of transmission system the risk of being struck by lightning insulation breakdown *.Unable to apply described.properties cable to the main reason is that this is a direct current (dc).To eliminate the space charge in the process of the various attempts, sumitomo electric puts forward 'even charge exists, if charge can uniformly distribute in the insulator, might have avoided the insulation breakdown' a new train of thought.So, everyone began to try in crosslinked polyethylene as the insulation material with filler."(Mr Asano)
Sure enough, we developed a special filling agent after repeated trial and error, after adding the filler, finally success to suppress space charge.Aimed at 250 kv from stage 1 (1988-1995), to target a 500 kv phase 2 (1993-2001), we constantly promoting research and development, achieve all the goals.
Just at this point, the first appeared in the north the Internet cable and cable laying of old.Demand for replacement, sumitomo electric finally realized in 2012 the "described.properties dc cable" in the world for the first time in the practical application.
"In the practical work, we must make very long cable.Unlike when the trial production, it is difficult to ensure quality uniformity in practical manufacture.Two companies around the necessary quality management and manufacturing process to carry out the discussion, this is the key."(Mr Asano)
Mr Asano, also referring to the installation engineering of impress him.
"Submarine cable and terrestrial cable is connected together by hand.If the cable accident, the most is the connection parts.Although this procedure need so high technical strength, but sumitomo electric fellow workers were very reliable in terms of skills and project management."(Mr Asano)
Our perseverance in the pursuit of leading specification development engineers, manufacturing site is extremely strict quality management, thoroughly to use its detailed engineering, quality, and complete all assignments with a high level of enthusiasm, the comprehensive strength of the sumitomo electric yielded good results, the project was finally completed.
* on the insulator of electric field intensity exceeds certain value, insulator electric breakdown will occur and resistance fell sharply, produce huge current
Welcomed the idea of reverse: "with filling agent"
Have a life in research positions and advance together described.properties dc cable legend, he is affiliated with the department of wire ・ energy career BeiZhao history.Since 1980 s into the job, he has been doing the r&d described.properties of dc cable.
"Described.properties dc cable research and development have been well, either.Even so, people can realize the practical application of large capacity transmission of the environmental protection cable, its research and development has never stopped."(Mr)
When Mr Began to study dc cable, the industry is underway to develop described.properties of 500 kv cable communication.Its key described.properties of insulating material (cross-linked polyethylene), is a kind of method, by changing the molecular structure of crosslinking to significantly improve polyethylene material softening problem at high temperature.
"For described.properties modified into can cope with the higher voltage insulation materials, research and development of worksite do 'can't introduce defects, defect of forming defects, can't,' ideal state is' not mixed with additives, infinite close to pure PE."(Mr)
People think that such views are also applicable to the dc power transmission cable insulators.But, in the ac power cable unprecedented new problems became the obstacle.As a result of the mentioned above reasons such as space charge accumulation, described.properties of past for dc voltage can only get insulation breakdown strength is much lower than expected.That is to say, based on pure polyethylene described.properties of communication cable cannot be directly used for direct current.At this point, bei transformation thought, thought of the "mixed with filler" this method.Filler became a breakthrough.In response to high voltage, he to detailed arrangement of filler components one by one, finally obtained the can solve the problem of composition and proportion.Further refinement, high purity and high decentralization homework, he finally developed special filling agent.It spread evenly in described.properties, finally making their way into material with excellent dc insulation properties.This is now sumitomo electric high voltage direct current transmission cable base described.properties of unique.This is the question, patient, results obtained from the search for the truth.
Bei laments: "university teacher who encouraged me to search for the truth, I can do is to really practice the teachings."After entering the 21st century, the work widely praised, sumitomo electric industries also formed a consortium, the work and university to push the production preparation.But not used an item is selected, the actual application has to wait for a period of time.The turning point in the 2010 s.Due to the east Japan earthquake in 2011, the necessity of the power company each other between power gradually highlights.As if in response to this demand, in 2012, north the grid line start putting-in-service proactively described.properties of dc cable.Now, the piece of shell as sumitomo electric researcher in training new people pour into heart, but he is engaged in the development of the will, as always steps.
"Although the world is in constant expansion and network cable, but from the status quo, is enough."(Mr)
In Japan, as a clean energy strategy, the government issued a new generation of the grid construction plan, dedicated to renewable energy sources such as offshore wind power from Hokkaido to places such as northeast and Tokyo.Constantly promote the liberalization of European power, people have the name "super power" to take the lead in building global grid, coupled with the introduction of renewable energy initiatives, international and the construction of a cable is dongfeng trotters.Countries and regions to achieve carbon neutrality, has begun to take formal action.Piece of bei sumitomo electric industries, such as technical personnel development by the "described.properties dc cable and cable at home and abroad to Japan" project as the object, is accelerating product supply.
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