Modeling of a Multi-level Converter Based MTDC System for the Study of Power System Steady-State and Transient Characteristics

Abstract

Multi-terminal High Voltage Direct Current HVDC (MTDC) systems are supposed to be one of the cost-effective ways to aggregate a huge amount of renewable energies on one side, and on the other side connect it to the main AC system through a common DC network. This paper investigates the dynamic performance of Voltage Source Converter (VSC) based Multi-terminal HVDC System in power transmission system, based on the analysis of the VSC model, the coordinated control strategy for the proposed MTDC system is discussed. Finally, a three terminal MTDC system is simulated for demonstrating the controller performance in the operation range against some steps change in power flow direction. Following that, typical operating contingency scenarios are simulated in order to evaluate transient performance. Simulation was carried out using PSCAD/EMTDC package.