November 27, 2019
Taiyo Nippon Sanso Corporation

Notice Regarding Operation of Turbo Refrigerator for High-Temperature
Superconducting Power Application in Russia(NeoKelvin®-Turbo 2kW)

Taiyo Nippon Sanso Corporation (“TNSC”) hereby announces that commercial operations havestarted for three units of the turbo-Brayton [Note 1] refrigerator NeoKelvin®-Turbo 2kW for use inthe superconducting fault current limiter equipment experimental project following delivery with
SuperOx LLC to UNECO, an electric utility in Moscow.

1. Delivery Background and Outline
In recent years, as demand for electricity has grown, Moscow has faced the need to increase thecapacity of circuit breakers in order to counter fault currents (particularly, short circuitaccidents) in the power grid. However, the high cost of these refurbishments had presented anissue for the city.
SuperOx, a Russian high-temperature superconducting wire manufacturer, and its Japaneseaffiliate SuperOx Japan had proposed that UNECO introduce superconducting fault current
limiters (“SFCLs”) [Note 2], and UNECO installed SFCLs for a 220 kV line at its substation inMoscow.
TNSC concluded an agreement with SuperOx Japan in 2017 to sell three of its NeoKelvin®Turbo 2kW units, and completed installation at a UNECO substation in Moscow in December
2018. Later, trial operations of the entire system, including SFCLs, were completed, the units
connected to the power grid and full-scale commercial operations launched.
2. Outline of NeoKelvin®-TurboTNSC has developed a turbo-Brayton refrigerator (NeoKelvin®-Turbo 2kW) with the coolingcapability of 2kW by using neon gas as the working fluid, as part of the “TechnologicalDevelopment of Yttrium-based Superconducting Power Equipment (2008 – 2012),” a project
led by the New Energy and Industrial Technology Development Organization (NEDO). TNSC
commercialized NeoKelvin®-Turbo 2kW in May 2013.
Moreover, in 2016, TNSC commercialized NeoKelvin®-Turbo 10kW, a unit with a coolingcapability 5 times greater than the 2kW model. Both the 2kW and 10kW models are undergoing
extensive trial operations worldwide for the cooling of high-temperature superconducting powertransmission cables.
(1) Features of the machine1）We have adopted active magnetic bearings for the turbo-machine to compress andexpand neon gas as it can be operated without mechanical contact by floating the mainshaft in the air to eliminate the maintenance.
2）We have adopted an energy-efficient structure in which the power generated by theexpander is returned to the compressor as regenerative power.
13）We have adopted a high-precision operating temperature control method based on
adjusting the rotational speed of the compressor.
(2) Specifications of the 2kW model (individual unit)
Refrigeration temperature: 70K (-203ºC) (Temperature of liquid nitrogen at the outlet of therefrigerator)
Refrigeration capability: 2kW
Power source voltage: 3-phase alternating current, 400V
Electricity consumption: 55kW
Cooling water: 250L/min
3. Developments going forward
If the current initiative can verify the competitive advantage of SFCLs, TNSC expects further
introduction in Moscow in the future, and we will continue initiatives to spread the popularityof the Company’s refrigerators going forward.

< Glossary>[Note 1] Turbo-Brayton refrigerator
This is a refrigerator to generate cold by four processes ((1) Adiabatic compression, (2)Isobaric cooling, (3) Adiabatic expansion, and (4) Isobaric heating). The neon gas that iscompressed by the turbo compressor ejects the compression heat into the atmosphere, then it
is expanded under adiabatic conditions by a turbo expander to lower the temperature of theneon gas.
After that, it absorbs the surrounding heat, which is returned to the inlet of the turbo
compressor. In the case of an actual refrigerator, a heat exchanger is inserted between theturbo compressor and turbo expander to collect the cold generated at the expander, generating
extremely cold temperatures.
[Note 2] Fault current limiter
This is one type of safety equipment designed to reduce the overload current swiftly ataccidents caused by short-circuit / electric leakage in the electricity transmission anddistribution system. Notably, superconducting fault current limiters have outstanding
responsiveness to fault currents because they make use of extremely rapid superconducting
phase changes.

Exterior of the NeoKelvin®-Turbo 2kW machine

Photo of an installed SFCL2