Submodule Test Circuit for MMC-based Voltage Sourced HVDC System

Abstract

A Voltage Sourced Converter (VSC) for High Voltage Direct Current (HVDC) operates in extremely high voltage and high-power conditions. Especially in case of Modular Multilevel Converter (MMC), hundreds of submodules are connected in series to meet the high voltage requirement. IEC 62501 suggests several tests such as the operational tests for a valve consisting of several submodules and the dielectric tests, etc. This paper proposes a new test circuit for the submodule in MMC-based HVDC system. Simulations are carried out for a system with the power rating of 2.4 [kV] and 485 [A], and both the simulation and scaled down experimental results show the validity of the proposed test circuit.