Supplier of 70% of the core products required in power supply in Korea
Korea’s first, world’s sixth in developing 765kV-class ultra-high voltage transformers in 1992
World’s first developer of 800kV class double-break gas-insulated switchgear (GIS) in 1999

Hyosung has been leading the power transmission and distribution industry in Korea for the past 50years with its main products of transformers, switchgears and substation solutions.Based on years of know-how in the local market, it has successfully expanded its business to markets across Europe, the Americas, and Central and East Asia, gaining recognition for its high standards of quality and safety. With its industry-leading technologies, the Power Systems Performance Unit offers a range of key products including transformers, Switchgears and provides comprehensive engineering and solutions with its expertise in power systems, i.e., engineering, design, manufacturing,installation, and testing, and maintenance service in power transmission, distribution and generation.To provide the best quality and service, Hyosung implements rigorous quality assurance policies and meets the ISO 9001 requirements. Hyosung is reinforcing its power condition monitoring and preventive diagnosis system, and IT-based power automation. To meet the global demand, the Power Systems Performance Unit is also strengthening global operations via Nantong Hyosung Transformer (established in China, 2006) and Hyosung T&D India Pvt. Ltd. (established in India,2015).


Ultra high voltage power transformer

ESB, IEC, ANSI, IEEE, NEMA, BS, JIS, JEC etc. based on the technical capabilities developed all domestically in products of all standards up to 765 kV at 154 kV and satisfying all international and national standards We produce transformers with quality and reliability.

Electrical equipment

We produced products with high reliability, stability and economy such as 25.8 kV GIS developed with design considering perfect insulation and safety, Package type receiving and transforming equipment integrated from the receiving end to the load end We are satisfying our customers.

Ultra high pressure circuit breaker(GIS、GCB)

It is the world's largest and most advanced level Changwon factory, producing state-of-the-art GIS and GCB, especially by developing the world's first 800 kV GIS which adopted a 2-way interrupter, it became a super-leading circuit breaker maker.

Distribution mold TR

Use copper (Cu) conductor excellent in electrical-mechanical characteristics. We are enhancing competitiveness by producing high-reliability products such as vacuum casting mold and glass Yarn insulation together with high / low pressure Coil.


Circuit breaker (Gas Insulated Switchgears Gas Circuit Breakers)

Standard & Voltage 72/145kV  :20/25/31.5/40kA
170kV   :31.5/40/50kA
245/300kV :40/50kA
362kV   :40/50/63kA
420/550kV :40/50/63kA
800kV   :50kA
Production Scope & Capacity 10,000 GVA/Year
& Strong point
Maintenance and repair minimization
Minimum installation time required & cost
Environmental affinity




Technology Core Form : Up to 765KV 2,000MVA
Shell Form : Up to 765KV 1,500MVA
Production Scope & Capacity 66~765kV, 10MVA-2,000MVA100,000 MVA/ year
& Strong point
High exclusion & high durability
High efficiency
Convenient operation
Morning maintenance fee



モ-ルド変圧器(Cast Resin Transformers)

Technology Type Up to 36KV 20MVA (AN)
Up to 36KV 30MVA (AF)
Production Scope & Capacity Up to 36kV 50~20,000KVA 2,500MVA / Year
& Strong point
No discharge
Space saving
Smoky property
Easy maintenance and repair

765kV Substation Transformer

1ph、765kV、2000MVA/Bank TR