Influence of Inverter Controller Parameters on the Small-signal Stability of LCC-HVDC System Based on a Practical Project

Huan Li,Kang Qin,P Siano,Q Li

doi:10.1051/e3sconf/202125601031

Abstract

Unreasonable control parameters of the Line Commutated Converter based High Voltage Direct Current (LCC-HVDC) system may induce small-signal instability. This paper studies the impact of inverter controller parameters on steady response of the LCC-HVDC system under weak AC grid condition. Firstly, according to a practical project, the small-signal model of LCC-HVDC system is established based on the switching function. Then, the eigen-analysis method is adopted to study the impact of the controller parameters on the inverter side on the oscillation mode and damping characteristics of the LCC system, and the correctness of results is verified by PSCAD/EMTDC simulation. The conclusion shows that reasonable controller parameters can improve the stability margin of the system.

Highlights

Line Commutated Converter based High Voltage Direct Current (LCC-HVDC) system has the advantages of lower loss and large capacity power transmission, which plays an important role in realizing the optimal configuration of cross-regional power resources [1]
When the inverter station is connected to a weak grid, some inherent problems of LCC-HVDC system may arise such as commutation failure and voltage instability issues
The results show that the stability of LCC rectifier station is enhanced with the increase of phaselocked loop (PLL) parameters, while the conclusion for the inverter station is just the opposite

Summary

Introduction

Line Commutated Converter based High Voltage Direct Current (LCC-HVDC) system has the advantages of lower loss and large capacity power transmission, which plays an important role in realizing the optimal configuration of cross-regional power resources [1]. When the inverter station is connected to a weak grid, some inherent problems of LCC-HVDC system may arise such as commutation failure and voltage instability issues. The occurrence of these problems is largely affected by control parameters of the system [2],[3]. In [7]-[8], the impact of PLL and constant extinction angle control parameters on the stability of the system is investigated based on a linearized dynamic model of the LCC inverter station.

Study system

State space model

Study parameters

Model validation

Small-signal stability analysis

Conclusions