Overview of DC–DC Converters Dedicated to HVdc Grids

February 19th, 2019|

This paper presents an overview of the dc–dc power converters dedicated to HVdc proposing a classification based on their structure. Two large families are established: those which provide galvanic isolation, and those which do not. Several subfamilies are also proposed. An overview of the main HVdc applications that can be targeted with each family is also presented, highlighting the main converter requirements for each application case.

FMEA of a non-selective fault-clearing strategy for HVDC grids

February 7th, 2019|

The Failure Mode Effect Analysis (FMEA) is a technique used to investigate failures in a process or component and to identify the resultant effects of these failures on system operations. In this paper it is explained how the FMEA can be used to define and assess the impact of the failure modes (FM) of a protection strategy for High Voltage Direct Current (HVDC) grids.

Virtual Capacitor Control for Stability Improvement of HVDC System Comprising DC Reactors

February 7th, 2019|

This paper first analyzes the underlying instability issue attributed to the DC reactor by using a simplified converter station model, which reveals that the DC-link capacitor can compensate for the detrimental effect of the DC reactor and increase the stability margin. This capacitor, however, is usually avoided and distributed over the capacitors in sub-modules in the state-of-the-art Modular Multilevel Converters (MMCs).

An Implementation Method for the Supervisory Control of High-Voltage Direct Current Transmission Systems

January 16th, 2019|

This paper presents an application of the SCT to HVDC grids and proposes an implementation method for the resulting supervisors. The proposed method is capable of integrating decentralized and discrete-event controllers that interact with the continuous-time physical system. The language chosen for the implementation is C code, as it can be easily incorporated in power system simulation software, such as EMTP-RV. The method is validated by the simulation of the start-up of a point-to-point link in the EMTP-RV software.