| Title |
DC Temporary Overvoltage Characteristics ofa ±35kV MMC-MVDC System by Fault Location and Type |
| Authors |
장민혁(Minhyeok Chang) ; 서치원(Chiwon Seo) ; 정소슬(Soseul Jeong) ; 장길수(Gilsoo Jang) |
| DOI |
https://doi.org/10.5370/KIEE.2025.74.12.2076 |
| Keywords |
AC/DC hybrid system; DC cable; EMT simulation; MMC-MVDC distribution; Temporary Overvoltage |
| Abstract |
This study quantifies temporary overvoltages (TOV) on DC cables of a ±35kV symmetric?monopole MVDC distribution link based on a half?bridge MMC. Using EMTP-RV EMT simulations under a unified control/protection setup, we compare DC?voltage responses for representative AC and DC faults, fault phase angles, fault locations, line lengths, and pre-fault loading. The results indicate: (i) among AC faults, single?line-to-ground yields the highest TOV; (ii) a pole-to-ground DC fault dominates the overall envelope; (iii) shorter lines increase the initial peak but accelerate decay due to reduced stored energy; and (iv) higher pre-fault power transfer increases the peak under DC faults. These trends provide starting points for cable insulation coordination and initial protection thresholds when converting existing AC feeders to MVDC. |