电力系统惯量需求:概念、指标及评估方法

Inertia Requirement of Power System:Concepts,Indexes,and Evaluation Method

低惯量运行风险是电力低碳转型过程中的重大问题,已成为制约以新能源为主体的新型电力系统可持续发展的痛点和关键瓶颈。惯量需求评估是实现系统低惯量风险感知与管控的基础。然而,当前惯量需求相关概念仍不明晰,未充分考虑故障类型和电网频率安全防线的影响,致使评估结果不够合理。文中从基本概念、表征指标和评估方法3个层面对电力系统惯量需求分析开展了研究。首先,考虑惯量支撑功率多阶段响应特征,给出了电力系统惯量需求的基本概念,并从能量和时序视角提出了惯量需求的量化表征指标。然后,综合计及故障类型和频率安全控制策略的影响,构建了一种适用于电网频率安全防线体系的惯量需求评估方法及分级机制。最后,以某实际电网为例,基于所提方法对其系统惯量需求进行评估和分析,验证了所提方法的合理性和有效性。

The low-inertia operation risk is a major problem in the process of low-carbon transition of electric power,and it has become a pain point and a key bottleneck restricting the sustainable development of new power systems with renewable energy as the main body.Inertia requirement evaluation is the foundation for realizing risk perception and control of low-inertia systems.However,the current concepts related to inertia requirements are still unclear and do not fully consider the influence of fault types and the security defense lines of power grid frequency,resulting in unreasonable evaluation results.This paper studies the inertia requirement analysis of the power system from three aspects:basic concepts,characterization indexes,and evaluation methods.Firstly,considering the multi-stage response characteristics of inertia support power,the basic concept of inertia requirement for the power system is proposed,and quantitative characterization indexes for inertia requirements are presented from the perspective of energy and time sequence.Furthermore,considering the influence of fault types and frequency security control strategies,an inertia requirement evaluation method and grading mechanism applicable to the security defense lines of power grid frequency are constructed.Finally,taking a provincial power grid in China as a case,the proposed method is used to evaluate and analyze the system inertia requirements,verifying the rationality and effectiveness of the proposed method.