https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/160 Fri, 03 Jul 2026 22:00:16 GMT 2026-07-03T22:00:16Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/212473 Title: Distributed DC voltage based grid forming control of interlinking converters in DC local grids Authors: Park, Su-Seong; Jung, Jin-Woo; Kim, Rae-Young; Lee, Dong-Geun Abstract: This paper proposes a distributed DC-voltage-based grid-forming control strategy for bidirectional interlinking converters in DC local grids. The proposed method establishes GFM (grid-forming) capability through DC-voltage synchronization among converters and enables sensorless droop operation using AC active power feedback. Small-signal analysis reveals the synchronous oscillation mechanism, which is mitigated using a notch-filterbased stabilization method. Simulation results demonstrate that the proposed control effectively suppresses synchronous oscillation and improves dynamic performance compared with conventional droop-GFM and DVSCGFM methods under various scenarios including weak-grid and increased renewable penetration conditions. Tue, 01 Sep 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/212473 2026-09-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213885 Title: Selective radiation emitters consisting of black silicon and photonic crystal for thermophotovoltaic systems Authors: Lee, Sung-Min Abstract: Highly radiative, wavelength-selective emitters are investigated for efficient Thermophotovoltaic (TPV) systems by integrating black silicon with a high-temperature one-dimensional photonic crystal (1D PC). The black silicon featuring a randomly distributed nanocolumn surface serves as an ideal black body emitter with high emissivity, while the 1D PC composed of alternating metal and dielectric layers provides spectral radiation selectivity and hence effectively suppresses radiation loss. Experimental results for 1D PC-integrated black silicon, fabricated using a scalable and potentially cost-effective method, show a two-fold improvement in spectral cut-off efficiency compared to pure black silicon. The robust operation under high-temperature conditions demonstrates its potential as a feasible emitter. Details of the design process, fabrication strategy, and quantitative characterization suggest the promising potential of combining ideal black silicon emitters with spectrally manageable photonic technology to advance TPV systems. Tue, 01 Sep 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213885 2026-09-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/211912 Title: Development of E-STATCOM analytical model for impact analysis of the southwest sea offshore wind farm linked system Authors: Park, Su-Seong; Lee, Dong-Geun; Kim, Rae-Young Abstract: An electromagnetic transient (EMT) analysis model is presented to evaluate the impact of large-scale offshore wind farm integration on the power system in the southwestern sea of Korea, in accordance with the 10th Basic Plan for Power Supply and Demand. An efficient E-STATCOM analysis model is developed by incorporating average representations of the MMC, DC–DC converter, and energy storage system (ESS) into an EMT framework, enabling system-level dynamic analysis with reduced computational burden while preserving essential transient behavior. Model parameters are derived based on power system characteristics and STATCOM ratings. The southwestern regional transmission system is converted into an EMT environment, and the operation and control modes of the proposed E-STATCOM are verified. The proposed model is comparatively evaluated against conventional EMT modeling approaches to assess dynamic fidelity and computational efficiency. The impact of E-STATCOM integration is analyzed mainly from voltage and frequency perspectives, considering variations in transmission lines, load conditions, and power generation before and after connection. The results confirm that the proposed EMT modeling framework provides an effective and scalable solution for analyzing large-scale offshore wind integration under weak-grid conditions. © 2026 The Authors. Mon, 01 Jun 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/211912 2026-06-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213228 Title: Gameplanner: A Game-Theoretical Landmark Planning for Multi-Agent Goal-Conditioned Reinforcement Learning Authors: Heo, Sunhaeng; Moon, Jun Abstract: Off-policy multi-agent reinforcement learning in decentralized settings faces key problems of non-stationarity and sparse rewards. When applied to goal-conditioned tasks, conventional planners often lead to conflicts and deadlocks, as each agent plans optimally only for itself while treating others as dynamic obstacles. To solve these problems, we propose Gameplanner, a framework that coordinates agents using a game-theoretical planner for goal selection, starting point selection, and landmark selection. In these three games, each agent’s choice is treated as a strategy, and a mixed Nash Equilibrium (NE) is computed to determine a mutually stable selection. Moreover, concerning the payoff for the landmark selection game, Gameplanner grounds game-theoretical planning in learning through a Learning-Guided Payoff (LGP), which uses each agent’s learned critic values to construct the game’s payoff matrix. This ensures that game-theoretical decisions are guided by individual learning progress. We demonstrate the effectiveness of our method in the AntMaze goal-reaching environment, where Gameplanner increases the success rate and enables stable, independent learning without centralized communication. Mon, 01 Jun 2026 00:00:00 GMT https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213228 2026-06-01T00:00:00Z