Transient Voltage and Current Stresses Estimation of MMC-MTDC System via Discrete-time Analysis

Identifier:  imarina:6251132

Handle: https://hdl.handle.net/20.500.11797/imarina6251132

Authors:  Chen, Yongyang; Huang, Meng; Pan, Shangzhi; El Aroudi, Abdelali; Zha, Xiaoming

Abstract:
IEEE Transient voltage and current stresses are essential for the design and protection of multi-terminal DC (MTDC) transmission systems, especially under the short-term dynamics after severe grid faults. In this paper, we propose a discrete-time model for the modular multilevel converter based MTDC (MMC-MTDC) system considering the DC-side disturbances in the system. Based on the piecewise linear modeling, the state variables such as the transient voltage on the sub-module (SM), arm current, etc., can be calculated analytically for the critical short term (within 10 ms) after the severe DC fault while the system protection is yet to be activated. Parameter sensitivity analysis is also performed to give a better system design guideline. The estimation results are validated by detailed electromagnetic (EMT) circuit simulations and the scaled-down experimental laboratory prototype.