View source for Milestone-Proposal:Gapless Metal Oxide Surge Arrester (MOSA) for electric power systems,1975

{{Proposal
|docketid=2013-01
|more than 25 years=Yes
|within fields of interest=Yes
|benefit to humanity=Yes
|regional importance=Yes
|ou is paying=Yes
|ou is arranging dedication=Yes
|section is taking responsibility for plaque=Yes
|a11=Yes
|a3=1975
|a1=Gapless Metal Oxide Surge Arrester (MOSA) for electric power systems,1975
|plaque citation=Gapless Metal Oxide Surge Arrester (MOSA) for electric power systems,1975

Meidensha Corporation developed MOSA and its mass production system by innovating on Panasonic Corporation’s ZnO varistor basic patent. MOSA drastically raised performance level against multiple lightning strikes and contamination and led to the UHV protective device development. This technology contributed to improving the safety and reliability of electric power systems and to establishing the international standards.
|a2b=Tokyo Section
|IEEE units paying=
|IEEE units arranging=
|IEEE sections monitoring=
|Milestone proposers=
|a2a=Meiden R&D Center
Meidensha Corporation　
2-8-1, Osaki, Shinagawa-ku　　　　　　　　　　　　　　 
Tokyo, 141-8565, Japan　

Latitude: 35.637915
Longitude: 139.715213
|a7=The MOSA had been developed at Meiden R&D Center since 1970s. Therefore, the intended site has a direct connection.
|a8=No, a new R&D building of Meidensha Corporation (“MEIDEN”) was rebuilt at same location.
|mounting details=We intend to install the milestone plaque at the secured zone in the entrance of Meiden R&D Center.
|a9=The people are able to see the plaque in the secured zone by getting inside the entrance hall of Meiden R&D Center.
|a10=Meidensha Corporation
|a4=Design of insulation in the power transmission system depends largely on the protective characteristics of surge arresters. As the power grids were expanding with higher transmission voltage in 1970s, the conventional arresters used in the age could not satisfy the new requirements.　 Conventional arrester with air gap was sometimes failed by natural phenomena for example multi-lightning and arrester housing pollution (contamination).
 
Electric power utility companies demanded the development of high performance surge arresters to be used for the next-generation UHV power transmission systems and also compact high-performance and high-reliability surge arresters to be used in the application for GIS (tank type arrester for gas insulated switchgear). 

Panasonic Corporation (Panasonic) had discovered ZnO varistor as a surge absorber for electronic devices below dozens of volts and defined its basic principle. Meidensha Corporation (MEIDEN) developed gapless surge arrester for power electric systems based on Panasonic’s patent. MOSA was the first gapless surge arrester that could meet the tough electric power systems application needs of world-wide power utilities. Consequently, conventional gapped type surge arresters were disappeared except some special applications.

MOSA has contributed to improving the reliability against multi-lightning and housing pollution-derived problems. Furthermore it ignited the births of  economical design for power network systems and power electric equipment.
MOSA became the de facto standard and later turned to JEC [1], ANSI [2], IEC [3] standards. It realized the electric power systems which has the very minimum power failure in the world.
|a6=To apply ZnO varistors to high-voltage gapless surge arresters, MEIDEN had the various issues/challenges to be overcome as shown below: 

1. Improvement of voltage-current characteristic of ZnO element and energy absorbing capability. (This was solved by finding the best balance of main ZnO component and several additives.) 
2. Preventing flashover outside by steep high current lightning. (This was solved by coating the ZnO element side with a ceramic insulator.)
3. Making sure that the life of the ZnO element when continuous voltage is applied to it over a long period of time. (This was solved by establishing a life estimation method and supporting field tests.)
4. Establishment of mass-production technology of ZnO elements for the power systems use. (This was solved by unique production system of ZnO elements which are mixed, granulated, formed, sintered into a complete block with electrodes on the both surfaces.)   
5. Contribution to establishing the application standardization of MOSA for power systems. (MEIDEN assisted and helped harmonization process by presenting the various papers (introducing the experiences from the actual MOSA production) at WG37.04, a sub division of IEC TC37 Technical Committee.)

For details, see [1]-[10] of `Significant References Column` below.
|a5=Conventional surge arresters for electric power systems were composed of combination of non-linear resistor element using silicon carbide ( SiC ) crystals and series gaps. As a result, they had the following disadvantages; 
a)	They couldn’t have high reliability against the housing pollution. This causes failure of arrester derived from two different components (gap part and SiC element) in same housing and couldn’t maintain stability for multiple lightning.

b) They couldn’t satisfy the social ( user’s ) requirements for high-performance, high reliability and compactness of arresters both for GIS ( Gas Insulated Switchgear / Substation ), and for Ultra High Voltage (UHV) transmission systems.

Overcoming obstacles cited above, MEIDEN developed gapless surge arrester to solve the above issues of conventional model: a) and b). MEIDEN commercialized MOSA in 1975 and the first supply was to 66kV Hayato Substation in Kyushu Area, Japan and completed the MOSA product series for 3kV to 500 kV electric power systems during 1977-1978. MOSA became the preferred choice and de facto major arresters in the world in a few years.
|references=[1] JEC 217-1984 (Japanese Electrotechnical Committee Standard in English)　
[2] IEEE/ANSI C62.22-1987
[3] IEC 60099-4-1991 
[4] T. Nishikori, T. Masuyama, M. Matsuoka, S. Hieda, M. Kobayashi and M.  Mizuno: “Zinc Oxide-based Gapless Surge Arrester for Electric Power Systems”, Paper for National Convention The Institute of Electrical Engineers of Japan (IEEJ), No. 777, 1973
[5] M. Kobayashi, M. Mizuno, M. Matsuoka and M. Tanaka: “Gapless Surge Arrester for Electric Power Systems”, Paper for Research Conference , IEEJ, PD-74-12（1974）
[6] M. Kobayashi, M. Mizuno, T. Aizawa, M. Hayashi and K.Mitani:　
“Development of Zinc-Oxide Non-Linear Resistors and Their Applications to Gapless Surge Arresters”, IEEE PAS, Summer Meeting, F77, 682-8 (1977), IEEE, Transactions, vol. Pas-97, No.4 (1978)
[7] M. Hayashi and M. Kobayashi : “Developing the First Gapless Metal 
Oxide(ZnO) Surge Arrester(MOSA) in the World “, IEEJ, Trans. PE, Vol. 128 No.3 (2008)
[8] K. Mitani: “Journal: Birth of Gapless Surge Arrester for Electric Power Systems”, Serial Articles of power industry newspaper “Denki Shimbun”, from Nov. 30, 1978 to Jan. 21, 1979 (6)
[9] Misao Kobayashi and Masao Hayashi: ”The background and history of developing Gapless Metal Oxide Surge Arrester (MOSA)”, Papers of Research Conference, History of Electrical Engineering (HEE), IEEJ, HEE8-19 and HEE10-002
　[10] United States Patent 4,031,498
NON-LINEAR VOLTAGE-DEPENDENT RESISTOR
|supporting materials=[11] Picture of MOSA for 66KV system used in Japanese electric company in 1975
[12] Picture of MOSA for 500kV GIS used in Japanese electric company in 1979
[13] Picture of MOSA for 500kV system used in Canadian electric company in 1979
|submitted=Yes
}}
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