Kyu Hoon Park

Hanyang University · The electrical system engineering

Medium voltage direct current (MVDC) transmission system are growing due to their assistive quality in conventional grid and compatibility with renewable power network. MVDC distribution links with “Mixed” overhead (OH) & underground (UG) sections could be devised based on urban planning. UG Cables or substations are indirectly exposed to lightning...

The black-box arc model is a tool that facilitates efficient research based on empirical studies in breaker design and analysis. However, its application has primarily focused on the design of ACCBs, with only a few instances of its implementation in the design of low-voltage (LV) DC circuit breakers (DCCBs) using mechanical methods. In DCCBs with...

The calculation of the continuous allowable current of an underground cable is determined by various characteristics. To calculate the allowable current in cables with alternating magnetic fields such as AC, special phenomena such as the proximity effect and skin effect must be applied. However, there are no standards or research related to the cal...

Bipolar lightning strokes are associated with multiple polarity electrical discharge with no current intervals in between, making their behavior quite peculiar. This work presents a fast front analysis of a mixed high voltage direct current (HVDC) transmission link, evaluating the factors that influence the line transients due to shielding failures...

Analyzing the arc interruption phenomena of circuit breakers, physical arc model is generally used, but its analysis and applications is complex because it requires understanding a lot of physical parameters such as thermodynamics and mathematical equations which occur during arc interruption process. But the black box model which simulate the dyna...

Many geographical constraints and aesthetic concerns necessitate the partial use of cable sections in the High Voltage DC (HVDC) transmission line, resulting in a mixed transmission line. The overhead sections of mixed lines are exposed to lightning strikes. The lightning strikes can not only result in flashover of overhead line (OHL) insulators bu...

The current and voltage in High Voltage DC (HVDC) line is not pure DC but contain superimposed ripple components. The current ripple in core of HVDC cable magnetically induces a voltage in the sheath, whereas the voltage ripple causes the flow of charging current from core to sheath. The knowledge of sheath voltage is necessary to ensure compliance...

The half bridge (HB) modular multilevel converter (MMC) technology is considered a breakthrough to mitigate the shortcomings of the conventional voltage source converter (VSC) in high-voltage direct-current (HVDC) grid application. However, interruption of the DC fault is still a challenge due to fast di/dt and extremely high levels of DC fault cur...

Growing urbanization coupled with increased power demands have led to an increasing use of mixed power transmission lines with sections of overhead lines (OHL) and the underground cables. Due to differences in surge impedance of cables and OHL, voltage surges experience reflections and refractions at their boundaries which make the transient behavi...

The black-box arc model is known to be a useful technique to simulate dynamic arc-circuit interaction by reflecting arc characteristics. Existing researches have shown that the black-box model has been widely used to analyse the ac arc characteristics of SF(6) and air circuit breakers. Due to the enormous energy and steep rise rate (di/dt) during d...

The key obstacle in implementing high-voltage direct current (HVDC) grid, which is considered as the future of power grid, is the absence of effective DC circuit breaker (DCCB). At present, HVDC grid could be based on half-bridge (HB) or full-bridge (FB) voltage source converter (VSC). Among these two converter topologies, FB topology has an advant...

The eventual goal of high-voltage direct-voltage (HVDC) systems is to implement HVDC grids. The modular multilevel converter (MMC) has been identified as the best candidate for the realization of an HVDC grid by eliminating the shortcomings of conventional voltage source converter (VSC) technology. The related research has focused on efficient cont...

To meet the growing power demand of the future, utilities and researchers have considered the addition of dc circuits in existing transmission corridors. The previous research has focused on analyzing the field environment, steady state induction and the negative effects of induction in the hybrid transmission lines. The overhead ground wires (OHGW...

The eventual goal of HVDC systems is to implement HVDC grids. One of the key obstacle in realization of HVDC grid is the absence of DC Circuit Breaker (DCCB). Several prototypes of DCCBs for HVDC grid have been proposed, but no commercial solution has been developed yet due to insufficient dc fault current breaking capabilities and unreliable prote...