面向区域间振荡模式的电力系统小扰动惯量域构建

为提升低惯量电力系统的小干扰稳定性,给出保障适应新能源发展的合理惯量裕度,并明确惯量分布对于互联系统小干扰稳定性的影响规律。研究了惯量分布对系统区域间振荡模式的影响规律,构建了面向区域间振荡的电力系统小扰动惯量域(Small Signal Inertia Region, SSIR)。首先,基于部分惯量中心(Part of the Center of Inertia,PCOI)等值方法和多项式Leverrier解法,构建了等值两机系统区间振荡模式阻尼比解析式。在此基础上,依据临界阻尼比构建了计及小干扰稳定约束的惯量域。进而,对区域互联系统惯量分布和小干扰稳定性之间的联系进行解析。最后,对惯量域进行全面分析,并在新能源系统中进行了初步验证。仿真结果表明,所提出的计算方法能够实现电力系统小扰动惯量域的准确、快速构建,增强低惯量电力系统小干扰稳定性的评估和监控能力,并为新能源惯量域的构建提供理论指导。

Construction of a small signal inertia region of a power system for inter-area oscillation mode

In order to improve the small-signal stability of a low inertia power system, a reasonable margin of inertia should be provided to ensure the development of new energy sources, and the influence of the inertia distribution on the stability of the system with small signals should be clarified. This paper studies the influence of the inertia distribution on the inter-regional oscillation mode of the system, and constructs a Small Signal Inertia Region (SSIR) of the power system for inter-regional oscillation. First, based on the Part of the Center of Inertia (PCOI) equivalent method and the polynomial Leverrier solution method, an equivalent two-machine system interval oscillation mode damping ratio analytical formula is constructed. Then, from the critical damping ratio, the inertia domain that takes into account the small disturbance stability constraints is constructed. Further, it analyzes the relationship between the inertia distribution of the regional interconnection system and small-signal stability. Finally, a comprehensive analysis of the inertia region is carried out, and a preliminary verification is carried out in the renewable energy system. The simulation results show that the calculation method proposed in this paper can realize the accurate and rapid construction of the small signal inertia region of the power system, enhance the evaluation and monitoring ability of the small signal stability of the low inertia power system, and provide theoretical guidance for research on the renewable energy inertia region. This work is supported by the National Key Research and Development Program of China (No. 2016YFB0900100) and the National Natural Science Foundation of China (No. 52007027).