Characterization of static voltage stability region of offshore wind farms considering submarine cable capacitance parameters and converter saturation

• Published in: International journal of electrical power & energy systems 2023-08, Vol.150, p.109095, Article 109095
• Main Authors: Tan, Hongtao, Li, Hui, Xiang, Xuewei, Zhang, Xiuqi, Yao, Ran, Zhou, Zhiting, Zheng, Jie
• Format: Article
• Language: English
• Subjects: Cable capacitance; Converter saturation; Offshore wind farm; Stability criteria; Static voltage stability region
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2023.109095

•This paper focuses on the influence of cable capacitance parameters and converter saturation on the system SVS, and establishes a SVSR assessment model for OWFs, the main contributions are as follows:•The analytical characterization model of PCC voltage considering submarine cable parameters is established, and the influence of cable capacitance parameters on system voltage characteristics is obtained.•The DC voltage stability is proposed to describe the static voltage instability caused by converter saturation, and the constraints of SVSR are summarized into three categories: power flow constraints, dq-axis stability constraints and DC voltage stability constraints.•The SVSR of the OWFs system is obtained by the intersection of multiple stability regions and Z-plane projection. Accurately characterizing the static voltage stability region (SVSR) is the key to ensure the safe and stable operation of offshore wind farms (OWFs). However, the traditional SVSR evaluation methods ignore the influence of capacitance parameters, and the stability criteria fail after d-axis current saturation, leading to a large deviation in the evaluation results. Therefore, this paper proposes an improved method to characterize the SVSR of OWFs, which takes the cable capacitance parameters and the saturation effect of the converter into account. Firstly, based on the equivalent circuit method, the power common connection (PCC) voltage charact- erization model considering cable capacitance parameters was derived. Then, the DC voltage stability was defined to describe the static voltage instability caused by the current limiting of the converter. The SVSR constraints are summarized into three categories: power flow stability, DC voltage stability and dq-axis stability, and stability criteria are designed according to different stability. Based on the method of intersection of multiple stability regions and Z-plane projection, the SVSR is characterized. Finally, the influence of different parameter settings on the SVSR is analyzed, and the accuracy of the proposed method is verified by RT-Lab experimental platform.