基于Gram-Charlier 级数的含风电电力系统静态电压稳定概率评估

Probabilistic evaluation of power system static voltage stability with wind power uncertainty based on the Gram-Charlier expansion

可再生能源的波动性和随机性加剧了传统电力系统静态电压稳定评估的难度。为了有效计及风电出力不确定性对静态电压稳定评估的影响,提出了一种计及风电出力不确定性的静态电压稳定概率评估方法。首先,借助电力系统负荷裕度,推导各节点负荷裕度对风电注入功率的灵敏度,进而求解负荷裕度的各阶半不变量和负荷裕度的各阶矩。然后,结合风电所连节点注入功率的各阶矩和半不变量,对负荷裕度各阶矩进行Gram-Charlier展开,以求取计及风电不确定性的负荷裕度概率分布,进而实现电力系统静态电压稳定概率评估。最后,通过IEEE30节点系统验证所提方法的准确性和有效性。

The volatility and randomness of renewable energy have exacerbated the difficulty of evaluating static voltage stability in traditional power systems.In order to effectively account for the impact of wind power output uncertainty on static voltage stability assessment,first,the sensitivity of each node load margin to wind power injection power is derived through the power system load margin.Further,each order semi-invariant and each order moment of power system load margin are determined.Then,combining the various moments and semi-invariants of the injected power of the nodes connected to the wind power,the Gram-Charlier expansion of the various moments of the load margin is carried out.Thus the probability distribution of the load margin is obtained by taking into account the uncertainty of wind power to realize the probability assessment of the static voltage stability of the power system.Finally,the accuracy and effectiveness of the proposed method are verified by the IEEE30 node system.