Improved Identification Method and Fault Current Limiting Strategy for Commutation Failure in LCC-HVDC

Jian Liu; Sheng Lin; Wenliang Zhong; Lei Liu

DOI:10.35833/MPCE.2021.000715


Improved Identification Method and Fault Current Limiting Strategy for Commutation Failure in LCC-HVDC



Page view: 0 Net amount: 161

Author: Jian Liu¹, Sheng Lin¹, Wenliang Zhong¹, Lei Liu²
Author Affiliation: 1. School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China 2. State Grid Sichuan Electric Power Research Institute, Chengdu 610072, China
Foundation:	This work was supported by the National Natural Science Foundation of China (No. 51977183).

Abstract:	Line-commutated converter based high-voltage direct-current (LCC-HVDC) transmission systems are prone to subsequent commutation failure (SCF), which consequently leads to the forced blocking of HVDC links, affecting the operation of the power system. An accurate commutation failure (CF) identification is fairly vital to the prevention of SCF. However, the existing CF identification methods cause CF misjudge or detection lag, which can limit the effect of SCF mitigation strategy. In addition, earlier approaches to suppress SCF do not clarify the key factor that determines the evolution of extinction angle during system recovery and neglect the influence. Hence, this paper firstly analyzes the normal commutation process and CF feature based on the evolution topology of converter valve conduction in detail. Secondly, the energy in the leakage inductance of converter transformer is presented to characterize the commutation state of the valves. Then a CF identification method is proposed utilizing the leakage inductance energy. Thirdly, taking the key variable which is crucial to the tendency of extinction angle during the recovery process into account, a fault current limiting strategy for SCF mitigation is put forward. Compared with the original methods, the proposed methods have a better performance in CF identification and mitigation in terms of detection accuracy and mitigation effect. Finally, case study on PSCAD/EMTDC validates the proposed methods.
Keywords:	Line commutated converter based high-voltage direct current (LCC-HVDC) transmission ; commutation failure identification ; commutation failure mitigation ; HVDC transmission control

Received:October 21, 2021 Online Time:2022/11/21



View Full Text Download reader