计及动态管存的电—气互联系统优化调度与高比例风电消纳

面向高比例风电接入下电—气互联系统(IEGS)的日前优化调度问题,首先提出了风电并网功率比例因子,将其作为控制变量引入风电的随机性模型中,使风电建模可反映风电不确定程度与并网功率的相关性。其次,基于天然气传输的动态管存模型及流量平衡方程,推导了动态管存特性在应对天然气负荷波动时所呈现的缓冲特性机理。进一步地,以IEGS外购能源费用最小为目标,计及动态管存特性,同时引入极限场景的优化方法,建立了含高比例风电的IEGS日前经济调度模型,并对模型进行线性化求解。最后,构建仿真系统,验证了动态管存特性对风电不确定性功率的缓解作用,可有效提升系统运行的灵活性。同时,得出电转气(P2G)设备的应用有利于提升风电消纳能力的结论,但该能力受到风电不确定程度的制约。

Optimal Dispatch of Integrated Electricity and Natural Gas System and Accommodation of High-penetration Wind Power Considering Dynamic Line Pack

This paper focuses on the study of optimized dispatching for integrated electricity and natural gas system(IEGS)under the background of high-penetration wind power. Firstly, the scale factor for wind power integration is proposed. This scale factor is introduced into the random model of wind power as a control variable so that wind power modeling can reflect the correlation between the degree of wind power and its grid-connected power. Then, based on the dynamic line pack model and flow balance equation of natural gas transmission, the mechanism of buffer characteristics exhibited by natural gas system is derived. Furthermore, taking the minimum purchased energy cost of IEGS as the target, taking into account the dynamic characteristics of the natural gas network, and introducing the optimization method of the limit scene, the economic dispatching model of IEGS with high-penetration wind power is established, and the model is linearized for solution. Finally, the simulation system is built to verify the mitigation effect of the line pack on wind power uncertainty, which can effectively improve the flexibility of system operation. In addition, it is concluded that the application of power to gas(P2G)is conducive to improving the wind power accommodation capability, but this capability is limited by the uncertainty degree of wind power.