PROJECT TITLE :

Control and Performance Analysis Methodology for Scale-up of MMC Sub modules for Back-to-Back HVDC Applications - 2017

ABSTRACT:

The modular multilevel converter (MMC) may be a promising topology for both Medium Voltage (MV) and High Voltage Direct Current (HVDC) applications. The MMC employs a massive variety of “submodule” (SM) cascaded in series per section arm to attain the MV- or HVDC voltage. The SM numbers per section arm will be as high as 256 or 512 SMs for +/- 300kV DC bus voltage for typical three hundred–600MW Back-to-Back (B2B) and additionally point to point HVDC applications. The MMC AC aspect interface voltage Total Harmonics Distortion (THD) requirements are normally < three% which will be achieved by forty eight-pulse stepped AC waveform. This paper addresses the first step towards scale-up management and performance analysis such that the behavior of a giant number of SMs will be predicted by a cumulative set of a smaller range of SMs. The SM capacitor voltage control is analyzed for scale-up of MMC. Simulation results of B2B HVDC application primarily based MMC system with minimum values of MMC components (SMs capacitors and arms inductors) based on a parametric search are performed using Real Time Digital Simulator (RTDS) system.