Voltage Security Analysis of VSC-HVDC Transmission Lines

TL;DR

This paper evaluates how VSC-HVDC transmission lines affect power system voltage security, highlighting the benefits of P-V control schemes and the challenges posed by P-PF schemes through reactive load margin analysis.

Contribution

It provides a systematic analysis of VSC-HVDC impact on voltage security, comparing different control schemes using a reactive load margin method on a real planning model.

Findings

P-V control schemes significantly enhance voltage security.

P-PF control schemes can negatively impact voltage stability.

Reactive load margin method effectively assesses HVDC impact.

Abstract

Due to generation retirements and growth of renewable energy sources integration, there will be widespread changes in the real and reactive power flow in nowadays power systems. These changes also bring about challenges on system operation and stability. High voltage direct current (HVDC) technology seems to be a promising solution to these new challenges. A study on the impact of the replacement of 500KV AC transmission lines by VSC-HVDC transmission line on system voltage security is conducted. The analysis is based on reactive load margin method and implemented on one of the Dominion Energy planning models. Different control schemes of HVDC are considered. Using k-means clustering method, three representative zones within the network are selected. The results corresponding to them are demonstrated and discussed. It is shown that HVDC lines with P-V control remarkably improve system voltage security, while those with P-PF control scheme have negative effects.