Adjusting converter controls for paralleled DC converters using a digital transient simulation program

Abstract

A description of how accurate system modelling of a dc system with an electromagnetic transient simulation program can be used to study and correct interbipole oscillations between converters connected into a parallel multiterminal system is given. The paper shows how to decide on the detail of modelling that is required, and demonstrates that it is often not enough to use prepackaged , generic HVDC control models, supplied with these programs. The detail of control models that are used in the electromagnetic simulation programs are shown to have a significant impact, in some cases, on the simulation results. In particular, a case of six hertz oscillations, in the dc currents of two converters on the Nelson River System, is accurately simulated, and it is shown that control modifications suggested by the simulation actually do eliminate the interbipole oscillations.

Electrical characteristics and transient analysis of HTS DC power cables for shipboard application

“…There have been research and studies for different topologies and configurations of rectifiers along with their pros and cons. According to some studies [16,17], there are several advantages in utilizing these devices as sources of DC in electric power electrical systems such as the reduction of Total Harmonic Distortion (THD) of input currents. Besides the reduction of the input current THD, they can improve the systems' Power Factor (PF) [18].…”