Emergency DC Power Support Strategy Based on Coordinated Droop Control in Multi-Infeed HVDC System

TL;DR

This paper introduces an emergency DC power support strategy for multi-infeed HVDC systems that uses coordinated droop control to enhance frequency stability during faults, validated through EMT simulations.

Contribution

It proposes a novel droop-based emergency support strategy and a coordinated optimization method for droop coefficients in MIDC systems, improving stability during HVDC faults.

Findings

The EDCPS strategy effectively stabilizes frequency during HVDC faults.

Coordinated droop control improves system resilience.

Simulation results confirm the strategy's effectiveness.

Abstract

With the complex hybrid AC-DC power system in China coming into being, the HVDC faults, such as DC block faults, have an enormous effect on the frequency stability of the AC side. In multi-infeed HVDC (MIDC) system, to improve the frequency stability of the receiving-end system, this paper proposes an emergency DC power support (EDCPS) strategy, which is based on a designed droop characteristic between the active power of LCC-HVDC lines and the receiving-end system frequency. Then, a coordinated optimization method is proposed to determine the droop coefficients of the MIDC lines. To test the proposed EDCPS method, the electromagnetic transient (EMT) model of a MIDC system is built on the CloudPSS platform, and the test results verify the effectiveness of the proposed EDCPS strategy.