中文摘要：

提出了一种考虑风电功率误差分布的电力系统改进风险评估方法,较传统评估方法更加精细地计算了系统运行风险。采用t-location scale（TLS）分布描述风电功率预测误差分布,与传统正态分布相比,可以更准确地描述风电预测误差分布情况。采用最优交流潮流模型计算最小切负荷量、节点电压和线路有功功率,与传统直流潮流模型相比,可以得到更准确的切负荷量和线路有功功率信息。计算了系统切负荷风险指标、电压越限风险指标、线路有功功率越限风险指标、电压崩溃风险指标,并引入了综合风险指标,结合风险等级的评判方法,更加全面合理地评估了系统运行的风险。此外,讨论和分析了不同风电接入节点、不同接入容量以及不同替换容量对系统运行风险的影响。从系统运行风险的角度,为电力系统规划风电接入容量和节点提供参考。最后,以IEEE RTS-79系统为例,对所提的方法和模型进行了分析和验证。

英文摘要：

This paper proposes a risk assessment method to improve accuracy for traditional method, with consideration of wind power forecast error distribution. In the proposed method, t-location scale（TLS） distribution is used to describe the uncertainty of wind power forecast error. Compared with traditional normal distribution and logistic distribution, TLS distribution performs better in approximating wind power forecast error. Optimal AC power flow model is used to calculate minimum load-shedding, node voltages and line active powers to obtain results more accurate than those for conventional DC power flow model. Detailed risk indicators are introduced to comprehensively evaluate power system risk, including load shedding, voltage violation, transmission line overload, and voltage collapse. Influences on system risk for different scenarios of wind power are analyzed and discussed, including different connecting nodes, capacities, and replacement capacities. This can provide references for planning of wind power capacity and location. At last, the proposed method is verified with modified IEEE RTS-79 systems.