大规模新能源接入的电力系统惯量缺失机理及惯量水平评估

Mechanism of Inertia Loss and Evaluation of Inertia Level in Power Systems with Large Scale New Energy Access

[目的]为满足我国“30、60”的碳达峰、碳中和目标,大量风电、光伏等新能源发电通过变流器接口接入系统,以替代燃煤同步机组出力,极大地影响了电力系统惯量及相应的频率动态特性。[方法]首先分析传统电力系统惯量运动方程及传统发电机扰动后的惯量响应阶段的功频动态过程,再定性讨论了大规模新能源接入后的系统惯性缺失机理。[结果]讨论了国内外常用的集中惯性评价指标,阐述了用系统的总动能和惯性常数作为电网惯性评价指标的依据。[结论]结合某省级电网的新能源开发和消纳的规划,对该省级电网的惯量水平进行了工程化评估,提出了相应的惯量提升建议。

[Introduction]In order to meet the national goals of"30·60"-peak carbon emissions by 2030 and achieving carbon neutrality by 2060,an influx of new energy sources such as wind and photovoltaic power is integrated into the system via converter interfaces and progressively supplants coal-fired synchronous generators,significantly impacting the power system's inertia characteristics and the associated frequency dynamic characteristics.[Method]Firstly,the study reviewed the inertia equation of motion for traditional power systems,and the power-frequency dynamic process during the inertia response phase following a disturbance in traditional generators,and then qualitatively discussed the mechanism of system inertia loss due to the extensive integration of new energy sources.[Result]The study considers evaluation indicators used at home and abroad for broadly recognized centralized inertia,and elucidates the reason for employing the system's total kinetic energy and inertia constant as the inertia evaluation indicators for the power grid.[Conclusion]Combined with the planning of new energy development and consumption of a provincial power grid,an engineering evaluation of the grid's inertia level is carried out,and the corresponding suggestions for inertia improvement are put forward.