Quantitative assessment of commutation failure risk and rapid identification of risk areas in HC-HVDC Receiving-end Power Grid

• Published in: Electric power systems research 2025-02, Vol.239, p.111270, Article 111270
• Main Authors: Wang, He, Liu, Sunao, Fu, Yuming, Bian, Jing, Li, Guoqing, Yu, Huanan
• Format: Article
• Language: English
• Subjects: Commutation failure risk area; Critical voltage for commutation failure; Generalized node voltage interaction factor; Hybrid cascaded DC transmission system; Receiving-end Power Grid
• ISSN: 0378-7796
• DOI: 10.1016/j.epsr.2024.111270

•The voltage interaction factor calculation method proposed in this article takes into account the DC characteristics of the system, and the derivation process uses branch addition method to reduce the inverse operation, resulting in faster calculation speed.•By carefully considering the dynamic characteristics of the system during the voltage drop of the commutation bus, an improved method for calculating the critical voltage of commutation failure is proposed, which has higher calculation accuracy.•The proposed quantitative evaluation index for commutation failure risk level and identification method for commutation failure risk areas can effectively and comprehensively evaluate the overall commutation failure risk level of the system. The hybrid cascaded DC transmission system based on LCC and MMC provides a more economical and flexible method for long-distance and high-capacity ultra-high voltage direct current transmission, but the uncertainty of commutation failure risk areas poses safety hazards to the system. In order to accurately and quickly identify the risk areas of commutation failure in the system, a generalized node voltage interaction factor calculation method considering the influence of the DC control system is proposed. Compared with traditional methods, it can more accurately quantify the voltage interaction between any two nodes in the DC receiving end power grid. Secondly, by establishing and solving the transient circuit model of the system during the voltage drop of the converter bus and considering the control characteristics of the system and the internal dynamic characteristics of MMC, an improved method for calculating the critical voltage of commutation failure is proposed, which improves the calculation accuracy. Furthermore, a quantitative evaluation index for the risk level of commutation failure and a rapid identification method for commutation failure risk areas in DC receiving-end power grids were proposed, effectively identifying weak areas in the DC receiving-end power grid. Finally, a detailed electromagnetic transient simulation model is established in PSCAD/EMTDC to verify the effectiveness of the proposed method.