Coordinated heat and power dispatch of microgrid considering two-dimensional controllability of heat loads

Abstract

考虑到区域内用户的热、电需求,近年来以微型燃气轮机为核心的热电联供系统在微网中得到广泛应用。如何协调调度微网的供热、供电,是提高可再生能源吸纳率、降低微网热电联供成本的关键。文中从用户供热舒适度的模糊性、微网供热系统的热惯性角度考虑,提出采用室内热舒适度指标将热负荷需求由传统的曲线转换为区间,从而使热负荷在各时间点上具有弹性;同时以自回归滑动平均(ARMA)模型描述供热系统多时段间的耦合关系,使供热量在时间轴上具有一定的可调节性。文中将上述两个特性统称为热负荷的二维可控性。算例分析了考虑热负荷二维可控性后,微网在孤网/并网运行时微型燃气轮机运行平稳性、弃风/光、购/售电量等方面,结果显示所述方法可有效减少热—电刚性耦合,为实现微网中热—电的时间平移和优化匹配提供了一种新思路。 By taking into account the heat and power demands of users in a microgrid, in recent years, the combined heat and power (CHP) system in which micro gas turbines are the core has been widely used. How to coordinate the heat and power supplies of a microgrid is the key to improving the accommodation of renewable energy source (RES) and reducing the CHP cost. The fuzzy character of thermal comfort and thermal inertia of heating system in CHP microgrid are considered. The predicted mean vote (PMV) index for evaluating the indoor thermal comfort is used to convert the traditional heat load curve to an interval, enabling the heat loads to possess elasticity at each moment. In addition, an auto-regressive and moving average (ARMA) model is used to characterize the multi-period coupling of the multiple temperature parameters in the heating system, i.e. thermal inertia, thereby making heat supply adjustable on the time axis. The above two characteristics together are called two-dimensional controllability of heat loads. In the simulation, considering two-dimensional controllability of heat loads, the operation stability of the micro gas turbine, wind/photovoltaic curtailment, electricity purchase/sales etc in the islanded/grid-connected mode are analyzed. And the results show that the proposed method can effectively weaken rigid coupling of electric power generation and heat supply, providing a new idea to the realization of the time shift and optimal matching of heat and power in a microgrid.