Investigations into LCC-HVDC Converter connecting to weak ac systems using various compensator configurations

Line-commutated Converters (LCC) have been used for over half a century due to their robustness as well as high power capacity. However, they can face challenges from voltage and frequency disturbances in the case of terminating in a very weak ac network. Such systems use synchronous condensers (SCs) to provide voltage and frequency support at the receiving end. A promising new topology for connecting SCs into an ac network has been developed at TGS (the industry partner). In this approach, the SC is interfaced with the network through an asynchronous by-passable back-to-back VSC link. This removes the requirement for the SC to operate at network frequency, thereby allowing much larger energy transfer to the SC’s rotating mass during under/over frequency events. Closing the bypass circuit breaker during normal operation allows the SC to perform its usual voltage control function in parallel with two converters which work as two STATCOMS. This provides the system with much more reactive power during voltage disturbances. The project aims to investigate the applicability of this approach in LCC-HVDC converters considering the range of operating contingencies.

Faculty Supervisor:

Aniruddha M. Gole

Student:

Partner:

TransGrid Solutions

Discipline:

Engineering

Sector:

Professional, scientific and technical services

University:

University of Manitoba

Program: