A local information integrated protection scheme for MMC-MTDC transmission system

Abstract

The integration of renewable energy sources has transformed fault characteristics in modular multilevel converter-based multi-terminal DC (MMC-MTDC) transmission systems, posing challenges to conventional protection schemes. This paper introduces an advanced protection scheme that leverages local information to address these challenges. The proposed scheme utilizes the DC voltage change rate as the initial criterion, adopts the polarity of single-ended differential current (SEDC) to identify faulted poles, applies the first derivative of DC transient voltage spectrum energy using the generalized S-transform to determine faulted DC lines, and employs local differential zone current (LDZC) to detect AC system faults in converters. A comprehensive MMC-MTDC test system is modeled in PSCAD/EMTDC to evaluate the performance of the protection scheme. Simulation results demonstrate that the proposed scheme offers rapid and reliable fault identification, effectively handling high fault resistance and noise across various fault conditions.© 2017 Elsevier Inc. All rights reserved.

Keywords

• Local information
• MMC-MTDC
• Fault characteristics
• Generalized S transform
• Protection scheme