PROJECT TITLE :

Modular Multilevel Converter DC Fault Protection - 2017

ABSTRACT:

High-voltage direct current (HVDC) grids can need the development of dc protections that provide fast fault isolation and minimize the disturbance caused to the present ac power networks. This paper investigates how the dc fault recovery performance of a half-bridge modular multilevel converter (HB-MMC) is impacted by totally different dc protection design choices. An HB-MMC purpose-to-point HVDC system that's protected with dc circuit breakers (CBs) is simulated on a true-time digital simulator using detailed switch models of the converters and switch gear. A dc CB controller has been developed and implemented in an exceedingly software-in-the-loop fashion, and has been created out there free for download. A novel blocking theme for the HB-MMC is proposed, which limits the possible dc-side fault current, benefiting dc switch gear. A comparison of circulating current controllers shows that the standard d -q controller is likely to be unsuitable for fault studies. Finally, benchmarking shows that a forty eight% reduction in power-flow recovery time and a ninetyp.c reduction in the energy dissipated in the circuit breaker can be achieved, together with different advantages, depending on the protection style.