中文摘要：

随着风力发电、太阳能光伏发电等分布式电源的并网运行，城市电网的潮流分布更加复杂。通过曲线拟合和特征值比较分析了负荷特性、风力发电和太阳能光伏发电系统出力特性及其对潮流分布的影响。仿真结果表明：城市电网的潮流分布受负荷变化的影响，同时具有规律性和随机性特征，太阳能光伏发电系统接人后会增强潮流变化的规律性，风力发电系统的接入则加大了潮流的随机变化。因此，在对城市电网进行潮流控制时，应同时考虑其变化的规律性和随机性特征。

英文摘要：

With distributed generations such as wind power generation and solar photovoltaic generation integrated in the power grid, the power flow in the urban power grid is more complicated. This paper, by curve fitting and eigenvalue comparison, analyzes the load characteristics and the output characteristics of wind power generation and solar photovoltaic generation as well as their influences on the power flow. The simulation result shows that power flow in the urban power grid changes with both regularity and randomness under the influence of load changes. The regularity of the power flow change is strengthened by solar photovohaic generation while the randomness is enlarged by wind power generation. There- fore, the characteristics of both regularity and randomness of the power flow change should be considered when measures are taken to control the power flow of the urban power grid.