Korea establishes its first ultra high-voltage DC standards, accelerating the “energy highway”

The Korea Research Institute of Standards and Science (KRISS, President Lee Ho Seong) has established Korea’s first national standards for the reliable performance verification of High Voltage Direct Current (HVDC)* transmission systems. Based on these newly established standards, KRISS will begin providing calibration and testing services for national power authorities and related industries.

* High Voltage Direct Current (HVDC): A transmission technology that delivers electric power in the form of high-voltage direct current, suitable for long-distance and large-capacity power delivery. In general, transmission efficiency increases with higher voltage. Voltage levels are typically classified as 30–220 kV for high voltage (HV), 300–1000 kV for extra-high voltage (EHV), and above 1000 kV for ultra-high voltage (UHV).

KRISS has now established measurement standards for 600-kV-class high-voltage DC, 800-kV lightning impulse, and 700-kV switching impulse measurements. With these standards in place, Korea now has a reliable basis for accurately evaluating and improving the performance of ultra-high-voltage power equipment—an advancement expected to strengthen the manufacturing quality and export competitiveness of domestic heavy electrical equipment companies.

* Heavy electrical equipment: A general term for facilities, systems, and components used to generate, transmit, and utilize electric power. Most power infrastructure—such as power transformers, cables, switchgear, and circuit breakers—falls under this category.

HVDC is a transmission technology that converts alternating current from power plants into ultra-high-voltage direct current. Compared with conventional AC transmission, HVDC offers significantly lower power losses and allows easier control of power flow, making it highly advantageous for long-distance and large-capacity transmission. Because of these characteristics, HVDC is emerging as a next-generation transmission solution for delivering electricity produced in non-metropolitan regions to the high-demand metropolitan area in a stable and efficient manner. At the first meeting of the National Power Grid Committee held in October, the Korean government identified HVDC industry development as a core strategy for building the nation’s “energy superhighway.”

According to growing market demand, Korean manufacturers have also accelerated the development of HVDC equipment. However, until now, the absence of national measurement standards for ultra-high-voltage testing has made it difficult for companies to certify product performance or advance into global markets. All heavy electrical equipment used in HVDC systems must pass performance tests specified by the International Electrotechnical Commission (IEC). But because Korea had no domestic measurement standards to objectively measure such performance, companies had no choice but to rely on overseas calibration bodies to conduct the required tests.

To address these challenges, the Quantum Electricity and Magnetism Metrology Group at KRISS has established new ultra-high-voltage measurement standards tailored for HVDC equipment. KRISS first expanded its previous DC high-voltage standard—from the 200-kV level to a 600-kV-class standard, tripling the available measurement range. This standard serves as the reference for withstand voltage tests, which evaluate whether power equipment can remain stable under voltages higher than normal operating conditions for a specified duration.

KRISS has also established new measurement standards for 800-kV lightning impulse (LI) and 700-kV switching impulse (SI) testing. Lightning impulses simulate the extremely high voltages generated when a lightning strike induces a sudden surge of current, while switching impulses replicate the transient overvoltages that occur when large power equipment is turned on or off. These two standards provide the basis for impulse voltage testing, which evaluates the insulation performance of power equipment under extreme high-voltage conditions that occur within a very short duration.

With the establishment of these standards, Korea now has a system that enables the testing and calibration of ultra-high-voltage equipment in accordance with IEC international specifications. This allows companies to conduct tests quickly and at their desired schedule, helping shorten the time required for product commercialization and enabling faster responses to market demand.

Dr. Lee Hyung Kew, Head of the Quantum Electricity and Magnetism Metrology Group at KRISS, stated, “Based on the newly established standards, KRISS has begun providing calibration services for HVDC testing equipment at KEPCO’s Gochang Electric Power Testing Center and at ILJIN Electric. We will continue to develop the ultra-high-voltage measurement standards needed by Korea’s power industry, contributing to the stability of the national grid and to strengthening industrial competitiveness.”

This work was supported by the Ministry of Science and ICT (MSIT) under the national R&D program for establishing a top-level measurement system and standard framework for intelligent power grids.