基于相对等效短路比的新能源——柔直送出系统振荡风险评估
Oscillation Risk Assessment of Renewable Connected to MMC-HVDC System Based on Relative Equivalent Short-Circuit Ratio
彭茂兰 1许诘翊 2严喜林 1冯雷 1谢小荣2
作者信息
- 1. 中国南方电网有限责任公司超高压输电公司电力科研院,广东广州 510663
- 2. 新型电力系统运行与控制全国重点实验室(清华大学电机系),北京 100084
- 折叠
摘要
新能源基地并网系统面临与电压支撑强度密切相关的振荡稳定性问题,在海量运行方式下,逐一建立精细化模型的稳定性分析过程耗时较长.短路比指标可直观反映新能源并网系统的电压支撑强度和稳定裕度,但现有短路比无法适用于无同步机电源的系统.为此,将短路比概念合理扩展至全电力电子化系统,基于戴维南等效网络来度量新能源-柔直送出系统电压支撑强度,进而提出了能快速评估新能源-柔直送出系统振荡风险的相对等效短路比计算方法,并阐明相对等效短路比能够全面考虑新能源场站发电功率、交流网架结构以及新能源设备变流控制系统等多重因素对振荡稳定性的影响,最后通过算例验证了相对等效短路比评估方法的有效性.
Abstract
The grid-connected system of new energy bases faces the oscillation stability issue closely related to voltage support strength.The process of stability analysis by establishing detailed models for mass operational conditions is time-consuming.The short-circuit ratio(SCR)can intuitively reflect the voltage support strength and stability margin of new energy grid-connected systems.However,the existing SCR is not applicable to the systems without synchronous machine sources.To this end,this paper reasonably extends the concept of SCR to fully electronic power systems,and the voltage support strength of renewables connected to modular multilevel converter based high voltage direct current(MMC-HVDC)transmission system is measured based on the Thevenin equivalent network.Thereafter,a calculation method for relative equivalent short-circuit ratio(RESCR)is proposed,which can quickly assess the system oscillation risk.The RESCR takes into account multiple factors affecting oscillation stability,including renewable energy generation power,AC grid topology,and renewable energy converter control systems.Finally,the effectiveness of the RESCR assessment method is verified through case studies.
关键词
新能源场站/柔性直流输电/构网型控制/电压支撑强度/振荡稳定性/相对等效短路比Key words
renewable energy station/MMC-HVDC/grid-forming control/voltage support strength/oscillation stability/relative equivalent short-circuit ratio(RESCR)引用本文复制引用
基金项目
中国南方电网有限责任公司科技项目(CGYKJXM20220061)
出版年
2024
NETL
NSTL
万方数据