Open Access

ARTICLE

Calculation of Commutation Failure Overvoltage in High-Voltage Direct Current Transmission Terminal Systems with Grid-Forming Renewable Energy Sources

Weibing Xu¹, Bo Yao^2,*, Xiangjun Quan³, Xunyou Zhang¹, Ning Zou², Shuo Liu², Jia Wang⁴, Jiansuo Zhang⁴

1 Mechanical and Electrical Engineering, Chizhou University, Chizhou, 247000, China
2 NARI Technology Co., Ltd., Nanjing, 210003, China
3 Electrical Engineering, Southeast University, Nanjing, 210018, China
4 State Grid Ningxia Electric Power Co., Ltd., Wuzhong Power Supply Company, Wuzhong, 751199, China

* Corresponding Author: Bo Yao. Email:

Energy Engineering 2025, 122(10), 4225-4243. https://doi.org/10.32604/ee.2025.066738

Received 16 April 2025; Accepted 12 August 2025; Issue published 30 September 2025

Abstract

The integration of large-scale new energy and high-capacity DC transmission leads to a reduction in system inertia. Grid-forming renewable energy sources (GF-RES) has a significant improvement effect on system inertia. Commutation failure faults may cause a short-term reactive power surplus at the sending end and trigger transient overvoltage, threatening the safe and stable operation of the power grid. However, there is a lack of research on the calculation method of transient overvoltage caused by commutation failure in high-voltage DC transmission systems with grid-forming renewable energy sources integration. Based on the existing equivalent model of high-voltage DC transmission systems at the sending end, this paper proposes to construct a model of the high-voltage DC transmission system at the sending end with grid-forming renewable energy sources. The paper first clarifies the mechanism of overvoltage generation, then considers the reactive power droop control characteristics of GF-RES, and derives the transient voltage calculation model of the DC transmission system with GF-RES integration. It also proposes a calculation method for transient overvoltage at the sending-end converter bus with GF-RES integration. Based on the PSCAD/EMTDC simulation platform, this paper builds an experimental simulation model. By constructing three different experimental scenarios, the accuracy and effectiveness of the proposed transient overvoltage calculation method are verified, with a calculation error within 5%. At the same time, this paper quantitatively analyzes the impact of grid strength, new energy proportion, and rated transmission power on transient overvoltage from three different perspectives.

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