多时间尺度电热综合能源系统状态估计研究

Multi-timescale state estimation for integrated electricity and heat system

电热综合能源系统的广泛发展促进了新能源消纳,提高了多能系统运行灵活性。然而,电力系统和热力系统运行时间尺度差异使得对电热综合能源系统进行准确状态估计较为困难。本文通过研究电热综合能源系统内的耦合和交互特性,通过有限差分法将描述热力系统动态特性的偏微分方程差分化,从而提出一种多时间尺度电热综合能源系统状态估计模型,并利用拉格朗日乘子进行求解。算例分析表明:本文所提多时间尺度方法对热力系统供水温度一段时间内的变化趋势估计与实测数据相比,其平均相对误差为0.27%,而稳态模型所得结果平均相对误差为1.03%,可以准确反映电热综合能源系统的多时间尺度特性。

The extensive development of integrated electricity and heat systems(IEHS)has promoted the absorption of renewable energy and improves the operation flexibility of multi-energy system.However,the time scale differences between electric power system and district heating system make it complicate to perform the estimation procedure accurately.In this paper,the coupling and interaction mechanisms in IEHS are studied.The partial differential equations describing the thermal dynamics are solved by the finite difference method,and the multitimescale state estimation model is proposed using Lagrange multiplier.Case studies shows that,compared with measured data,the average relative error of the proposed multi-timescale method on evaluating the change of supply water temperature within a period is 0.27%,while that of the steady state model is 1.03%.The proposed multitimescale method can accurately describe the multi-timescale characteristics of the IEHS.