First-Hand:A Birth of Gapless Metal Oxide Surge Arrester (MOSA) and Early Days of Its Promotion Activities


Submitted by Misao Kobayashi, Current Representative of Surge Protect K.K., (Former Chief Engineer of Meidensha Corporation, a key project member of MOSA R & D programs)

Introduction (in Brief)

In the 1970s, the serious challenges for world surge arrester industry were: improvement of reliability, more compact design, and capability for UHV application. In 1967, Matsushita Electric Industrial Co., Ltd. (present ‘Panasonic Corporation’) made an epoch-making discovery on varistors for household electric appliances. Meidensha Corporation (“Meiden”) made a joint research project with Panasonic, and on that basis, Meiden developed and commercialized Gapless Metal Oxide Surge Arrester (MOSA) for electric power systems. MOSA had to go through the process of international standardization starting from technical discussions at CIGRÉ (Conseil International des Grands Réseaux Électriques (in French)/The International Council on Large Electric Systems (in English)) before JEC Standard (1984), IEEE Standard (1987) and IEC Standard (1991) were established. On the other hand, MOSAs became the major choice (de facto standard) for surge arrester for electric power systems, and since 1977, they have been used worldwide even before the international standards were drafted. I would like to give you a snapshot of how it was like back then (our inventions, difficult moments, efforts, and good memories). Also, I’d like to tell you my thought and opinion about why Meiden could make it, not bigger heavy electrical companies in Japan doing the surge arrester business.

Background of Development at Meiden and Penetration at Home and Abroad (Main Text)

Back in 1970, conventional gapped type surge arresters were mostly used. They consisted of SiC resistor elements (non-linear resistor) and spark gap in-series and were enclosed in insulation housing (porcelain enclosure). The SiC resistor elements did not have sufficient voltage and current nonlinear characteristics. In order to prevent the heat generation or resultant burnout damage by the effect of the resistive current (dozens~several hundreds of ampere) under continuous operating voltage, the use of in-series gap was a must. Therefore, the burnout accidents caused by the multiple lightnings and housing surface contamination (e.g. contamination by salts or dust) were unavoidable in principle. The conventional gapped type surge arresters could not fully meet with the demands of the high information society of “no outage”. These defects remained as issues which could not be solved in the world surge arrester industry.

Meiden’s President Hiraki at that time saw a newspaper press release that Panasonic’s metal oxide varistor (whose main ingredient was zinc oxide (ZnO)) for light electric appliance might be applicable for electric power systems application (May, 1970). Meiden contacted Panasonic and started the joint research program of metal oxide varistor for electric power systems. After the success of the joint research program, we received a patent license from Panasonic by the agreement, and then embarked on the self-development program of ZnO elements for electric power systems. Together with Panasonic, Meiden announced the world-first technical paper on 66kV MOSA at the national convention of the Institute of Electrical Engineers of Japan (IEEJ) in 1973. In 1975, we supplied the world-first 66kV MOSA for Hayato Substation of Kyushu Electric Power Co., Inc. This record became the subject of IEEE Milestone Award, which Meiden received this time.

Based on the positive results of the first supply record, since 1977 in Japan, each electric power company came to adopt the MOSAs gradually. In 1979, the standardization work of JEC in Japan kicked off, and in 1984, the world-first MOSA standard, JEC-217, was established.

Meanwhile, in order to promote IEC standardization, at first Meiden contributed an English paper to 1977 IEEE Summer Meeting (SM) and joined the technical discussions at several CIGRÉ working group (WG) 33.06 (insulation co-ordination): at the Dublin Meeting (1977) and at the Paris Session (1978) . The standardization of the gapless MOSA was proposed and approved at the Warsaw Meeting (1979) of IEC TC37 (surge arrester). The draft went through the technical reviews by IEC professional members for five years (1980-1985) by WG37.04 (MOSA) and the final draft was completed in 1985. Due to some dissenting opinions from several countries at IEC Main Committee, it took six years for full clearance at IEC Main Committee and the standard was enacted in 1991. For your information, compared with the IEC final draft completion in 1985, the JEC standard was enacted in 1984 (one year ago) and the IEEE standard was enacted in 1987 (two years later.)

Commercialization and Efforts for Wider Market Penetration (Strategy, Hard days and My memories)

Regarding the commercialization and market penetration programs, they went side by side with the R & D programs at Meiden. The people in the sales front faced the “Chicken and Egg Issue” (The customers would ask: “Do you have a track record of such product?” Our reply would be: “Without the first adoption by any power utility, how could we make a track record?”). As a measure, we proposed and implemented joint research programs with the major power utilities in Japan to meet the needs of their major requirements. After gaining the field experiences and track records, we promoted the MOSA standardization in Japan and along the way, we supplied world-first MOSA products. Through these efforts, we could come to tell how to get there with the JEC standardization on MOSA. For the promotion of IEC standardization, we attempted to serialize the MOSA products for 3.3-275-kV power systems. After conducting the open type tests for all power utilities in Japan using the internal technical specification draft used at Meiden, I contributed a technical paper to 1977 IEEE SM (Mexico Meeting) using the results of such open type test. We promoted the technical discussions at CIGRÉ and IEC. However, as I mentioned earlier, it took some more years until IEEE standard and IEC standard were established.

These activities were evaluated. I received many honors, such as various awards at home and abroad (The Okochi Memorial Award, Medal with Blue Ribbon (national medal given to an individual contributing for the benefit of public interest), IEC1906 Award (recognition of exceptional current achievements of experts), etc.), and was nominated as ‘CIGRÉ Distinguished Member’, and ‘IEEE Fellow’. Moreover, I could have and am still having the friendly contacts with key members of CIGRÉ SC33, IEC TC37, and IEC TC28 during my active days. I still reminisce about those days.

Conclusion (Closing Remark)

One of the frequently asked questions (FAQs) from academia or industrial circle is "Why could Meiden, a midsized heavy electrical company, make such a great invention?” I thought about it and came to a personal conclusion as below. As old Japanese saying goes, “From the ancient period, there are three key factors for success (KFSs) : Timing from Heaven, Advantage of the Land (being there), Harmony among People (serendipity by the people’s connections). My conclusion is: “A miracle happened. The three KFSs got together by chance.” Such a case happens very, very rarely. “We were very much blessed.” Another luck was: I happened to be one of the key project members for MOSA development programs. I thank God for my luck!

Further Reading

Gapless Metal Oxide Surge Arrester (MOSA) for electric power systems, 1975 IEEE Milestone