An enhanced commutation failure prevention control in LCC based HVDC systems. (February 2023)

• Record Type: Journal Article
• Authors: Liu, Lei; Li, Xiaopeng; Teng, Yufei; Zhang, Chun; Lin, Sheng
• Is Part Of: International journal of electrical power & energy systems. Volume 145(2023)
• Publication Date: 2023-02
• Subjects: HVDC transmission system -- Commutation failure -- AC faults -- Predictive control -- Pseudo commutation process; Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2022.108584
• Languages: English
• ISSNs: 0142-0615

Abstract

Abstract: Most commutation failures in high-voltage direct current (HVDC) systems are caused by AC faults on the inverter side. Conventional control methods for commutation failure prevention are on the premise of fault detection. However, a time period between the occurrence and detection of faults is inevitable. There are no effective control methods yet dedicated to this time period to mitigate commutation failures. In this paper, an enhanced commutation failure prevention (ECFPREV) control method is proposed. During the stage that a fault has taken place but not been detected, the proposed scheme still contributes to regulate the firing angle slightly for better commutation failure mitigation performance. To achieve this, a novel concept of pseudo commutation process is presented first, so that commutation processes with time delay can be performed in near real-time. Based on the constructed pseudo commutation voltage waveform, pseudo commutation parameters can be calculated at each sampling instant. Then, the ECFPREV, which is equipped with a pseudo firing angle prediction module, is proposed. An appropriate firing angle is calculated precisely for each pseudo commutation process regardless the fault detection signal, thus keeping a sufficient commutation margin for the upcoming real commutation process. The feasibility of the proposed strategy is validated through the CIGRE Benchmark HVDC model in PSCAD/EMTDC platform. Simulation results demonstrate that the proposed ECFPREV control is able to effectively improve the commutation failure immunity of HVDC systems. Highlights: A novel concept of pseudo commutation process in HVDC is proposed. A pseudo firing angle prediction module is designed to collaborate with CFPREV. The proposed method regulates firing angle timely to prevent commutation failure.