考虑频率稳定性的新能源电力系统惯量水平多区间评价方法

Multi-interval evaluation method of inertia level of new energy power system considering frequency stability

随着大量新能源机组取代同步发电机接入电网,系统惯量水平的下降将威胁系统频率稳定,但基于频率稳定评价系统实际惯量水平与充裕度的方法仍相对较少。本文通过量化分析惯量与频率动态响应的关系,提出一种新能源电力系统的惯量分区评价方法。首先,基于新能源电力系统频率响应模型求解,并借助提出的惯量灵敏度指标分析惯量对相关频率安全指标的影响。然后,依据频率稳定约束与综合惯量灵敏度指标确定区间边界,构建惯量危险区、惯量敏感区和惯量饱和区三类惯量水平区间,并分析潜在最大扰动功率及调频能力对区间边界的影响。进而,提出惯量安全性系数与充裕度系数评价系统当前惯量的水平高低。最后,在DIgSILENT中建立IEEE10机39节点标准系统,仿真验证了所提系统惯量分区评价方法的有效性与可行性。

As a large number of renewable energy sources replaces synchronous generators and connect to the grid,the decrease of system inertia will threaten the frequency stability.However,there are few methods to evaluate the actual inertia level and abundance based on frequency stability.A new energy power system inertia partition evaluation method was proposed by quantitatively analyzing the relationship between inertia and frequency dynamic response.Firstly,based on the frequency response model of the new energy power system,the sensitivity of inertia was proposed to analyze the influence of inertia on the relevant security indexes.Secondly,two boundary values of the interval were determined according to the frequency safety constraint and the comprehensive sensitivity of inertia,respectively.Three inertia level intervals were constructed:dangerous zone,sensitive zone and saturation zone.And the influence of potential maximum disturbance power and frequency modulation capability on the inertia intervals was discussed.Furthermore,the inertia adequacy coefficients were proposed to evaluate the level of the actual system inertia.Finally,the IEEE10-machine 39-node standard system was established in DIgSILENT,and the simulation verifies the validity and feasibility of the proposed system inertia partition evaluation method.