Relay protection and automation advancement mainspring is develohment and manufacture of products, which fit the long-term requirements of consumer equipment. Increase in energy facility consumption leads to necessity of applying commutate equipment with increased switching power. Products with polarized magnetic system hold a specific position among commutate equipment due to variety of advantages: reduction in current consumption, increasing of switching power, extension of relay lifetime. From 30 polarized relay magnetic circuits, contained in section 1.2 [1] only in three circuits 1-7м, 1-7ф, 1-7х cast magnets mode ЮНДК35Т5 are applied with their volume efficiency, with side plane area to magnet height proportion about 5 mm. Only circuit 1-7ф (pic.1) proved viable among them with «active tongue» applied in РПС45 and РПС46 relay. Those relays are one of the most common polarized bistable relay in Russia, which produced in lots more than 30 years. Circuit 1-7м (pic.1) dismisses a use of a standard flux transition technology of flux, which generated by constant magnets demagnetization, magnetizing being a part of a purchased item for the purpose of compliance of constant magnets flux with winding magneto-motive force and item mechanical characteristic. Circuit L (pic.1) is similar to circuit 1-7м, but it has one constant magnet, is widely used in modern relays produce both in Russia and abroad.

Pic.1 Polarized relay magnetic circuits

Described above standard technology or the one, comparable in relay control efficiency, proved to be the one of the key element of circuit and relay design viability.

On the site of Research and production company “Severnaya Zaria”, JSC on pic.6 [2] a standard relay design is displayed, which at the moment of the first adoption in Russia was widely used in LEACH relays and contactors (USA, France) [3], the dominant company in western market of relays and contactors designed for aerospace and military use. Since the beginning of the 90-th XX century LEACH actively and successfully marketed the product in Russia, resulting in multiple import phase-out programs in terms of extensive reproduction.

Consequently off the shelf relay performance level not always conformed the foreign equivalents characteristics, owing to the lack of similar domestic materials, supplements and technologies. Sanctions in place today against Russia confirm relevancy of import phase-out programs. Yet consumers more often prefer not to substitute foreign relays for domestic off the shelf equivalents, pointing their disadvantages. Overcome the trends it became ripe the necessity to upgrade the design shown on pic.6 [2] for obtaining performances reliably higher than the one of LEACH relays. The upgrade may base upon design and technological decisions on a point of rare-earth magnet.  

The first application of rare-earth magnets (type КСП37 as per GOST 21559-76) in commutation switch, stock-produced in the USSR, was headed by Gordon A.V. development of single-shot contactor product run mode 03ОДА и 01ОДА [4, 5]. Still high energy, supercritical rare-earth magnets did not receive further application in commutation switchesа for more than 30 years, in spite of apparent advantages over alnico cast magnets (ЮНДК alloy).

There is no information on the use of such magnets in domestic relays and contactors available to the public in press and on enterprises sites. However, domestic relays design analysis showed, that in polarized bistable relays mode РЭП33, РЭП43 и РЭП44 [6-8] developed by «VNIIR», JSC at early 2000-s high energy constant magnets Nd-Fe-B are to apply.

The original electromagnetic circuits considered by “KBEA”, LLC with “active” balanced armature with rare-earth magnets, which makes it possible to enhance several times clearance between contacts, but did not found engineering implementation yet.

KBEA engineers’ active search for solution for high-energy rare-earth constant magnets application, permits to conclude about a new polarized equipment development need with polarized application, as per GOST РВ 5945-002, with extended from 750 W to 4000 W and from 3000 VA to 10000 VA power handling by operation voltage rise. Otherwise, developed makes of relay for rated current up to 25 А should comply with this standard.

Industrial relay consistent in terms of electromagnetic system with specialized application relay in hermetic enclosure made of modern thermoplastic should be able to commutate increased overload up to 10 I and short-circuit current up to 20 I.

Between now and 2022 it wise to plan research and development of switching relay in plastic hermetic enclosure, rated current modification 10, 25, 50, 75, 100, 150 A, as well as R&D of overload and short-circuit current protection equipment with spare circuit set. The auxiliary contacts can be with modular construction and commutate currents from 5 uA up to 1 A, 27 V, for example reed contact.

Today KBEA specialists carry out investigations in order to increase switching power, voltage. This item is actual for modern automotive industry [9]. Received relay switching power is 6000 W for 30000 cycles and 50000 W for 200 on-off-cycles.

The similar technologies (magnetic blow with constant magnets made of supercritical hard ferrits, sealing with dry nitrogen pad of the inner space) would not cause difficulties in Russia, more to the point, the modern resin-bonded magnet instead of ferrites usage can three times increase magnetic field intensity at arcing area and reduce relay costs. Yet, it can complicate electromagnetic system work to apply magnetic blow for arc quenching, as well as relay magnetic system itself in some polarized circuits can effect on arcing process.

For complete check out of factors, which can effect on the relay steady operation, it is need to conduct severe test of modern technologies application.

KBEA will appreciate colleagues’ opinion about on the foregoing and invites potential consumers and other interested organizations for co-operation.

References: 

1. Ройзен В.З. Электромагнитные малогабаритные реле. - Л.: Энергоатомиздат. Ленингр. отд-ние, 1986.

2. Малащенко А. А. Слаботочные реле и «Северная заря».- https://relays.ru/relay.html

3. Short form catalog. Components & Solutions.- https://www.esterline.com/Portals/3/Literature/EPS_Relay_Short_Form_Catalog.pdf

4. Электромагнитные контакторы однополюсные с замыкающими контактами серия 01ОДА.- http://www.aeroem.ru/products/jelektromagnitnye-kontaktory/elektromagnitnye-kontaktory-odnopolyusnye-s-zamykayushchimi-kontaktami-seriya-01oda/

5. Электромагнитные контакторы трехполюсные с замыкающими контактами серия 03ОДА.- http://www.aeroem.ru/products/jelektromagnitnye-kontaktory/elektromagnitnye-kontaktory-trekhpolyusnye-s-zamykayushchimi-kontaktami-seriya-03oda/

6. Реле электромагнитное двустабильное РЭП33.- http://www.vniir-progress.ru/production/equipment/rele-elektromagnitnoe-dvustabilnoe-rep33/

7. Реле электромагнитные двухстабильные типа РЭП43-300.- http://www.vniir-progress.ru/production/equipment/rele-elektromagnitnye-dvuxstabilnye-tipa-rep43-300-2/

8. Реле промежуточные серии РЭП44.- http://www.cheaz.ru/upload/uf/f2b/f2bc5a62ba1d8374e85bda010bc1b2b2.pdf.- С.30.