An electromagnetic transient simulation model for voltage sourced converter based HVDC transmission

Voltage sourced converter based high voltage DC transmission (VSC-HVDC) is an emerging technology for the efficient transfer of energy. Because it uses gate turn-off semiconductor devices, such as GTO or IGBT, the VSC-HVDC option offers several advantages over conventional HVDC transmission. It can operate into very weak AC systems as well as provide auxiliary services such as reactive power support to the AC network, although it currently suffers from higher losses and lower power ratings. As this is an emerging technology, it is important to develop tools and models for the study of VSC-HVDC in various operating conditions. With this in mind, the paper develops an electromagnetic transient simulation model of a 300 MW VSC-HVDC scheme that can be used for investigating its operation. A decoupled control system is developed and the transient performance and fault behavior of the system is studied under different short circuit ratio (SCR) conditions.