Regional HVDC interconnection and its impact on network performance
November 5, 2019

HVDC transmission links are a viable alternative for transmitting power over long distances. With large scale renewable energy availability being limited, HVDC links are being utilized to transfer renewable energy to a load center. PSC’s engineering specialists have completed system studies and analysis on a proposed HVDC link exceeding 300 miles in length intending to transmit renewable energy between two countries.

​In response to a request for proposals solicited by government agencies seeking long term renewable energy projects, a 1000MW Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) link to transmit renewable power from Canada to the United States had been proposed for consideration.

PSC performed system impact studies to identify any possible power system issues in relation to system technical performance requirements that may be introduced into the transmission system due to the inclusion of the proposed project. The studies also identified how Flexible AC Transmission System (FACTS) devices can assist in improving the dynamic stability of the system.

Two main types of power system analysis – load flow and stability – were completed for a variety of scenarios. The former was performed to check violations against system voltage and transmission line and/or equipment thermal loading limits. The stability analysis, based on dynamic system simulation studies, was aimed at establishing whether there will be transient voltage stability issues. Additional sensitivity analysis was carried out at various stages to establish robustness of the attempted mitigation measures. These steady state load flow and dynamic system stability studies were conducted for three main operational planning scenarios.

A technical paper was also prepared for the CIGRE B4 International Colloquium that was held in Johannesburg, South Africa in October. This paper summarized the methodology that was adopted and the critical analysis that should be performed when an HVDC system is introduced in parallel to an existing AC system. The paper also outlined how recent technology advancements could be utilized to transmit large amounts of power and at the same time improve the overall network stability and reliability. With series compensation and VSC, system stability issues associated with adding the VSC HVDC link were mitigated in this project.

For more information on the technical paper, please contact PSC’s Technical Director Dr. Zia Emin – [email protected]