分布式冷热电联供系统负荷随机模糊建模

摘要

In view of the coexistence of randomness and fuzziness for the natural gas based distributed combined cooling , heating and power (CCHP) system load , effective extraction of its uncertain characteristics is of great significance for system optimum scheduling and operation . A random and fuzzy modeling method is proposed . First , based on historical CCHP cold/heat/electricity load data , it has been found that the probability distribution characteristics can be described by weighted sum of n‐stage normal distribution , and the probability density functions of electricity load and cold/heat load are obtained . Further , the function parameters are analyzed and found without complete statistical property but epistemically obscure . By extracting the characteristics of the membership function and the credibility density function of parameters , the electricity load and cold/heat load are defined as random‐fuzzy variables . Based on following the thermal load ( FTL ) , the coupling characteristics between electric load and cool/heat load are analyzed , so the random‐fuzzy model for daily exchange power of CCHP with power system is proposed and the corresponding random‐fuzzy simulation method given . Case study is carried out based on operation and load data from a CCHP connected to a 10 kV bus in a city in Hunan Province , The effectiveness and validity of the proposed model is proved by simulation results .%基于天然气的冷热电联供（CCHP）系统负荷随机性和模糊性共存，有效提取其不确定特征对 CCHP 系统优化调度运行有重要意义。文中提出一种分布式 CCHP 系统负荷随机模糊建模的方法。首先基于 CCHP 系统冷热电负荷历史数据，发现其可以用 n 阶正态分布加权和方法描述其概率分布特征，并获得电负荷与冷热负荷的概率密度函数，进一步分析该函数的参数，可知其不具有完全的统计性质，因而具有认识意义的模糊性，通过对参数的隶属函数和机会测度函数特征的提取，从而定义电负荷与冷热负荷为随机模糊变量；其次分析电负荷与冷热负荷两类变量之间的耦合特性；最后结合随机模糊模型及各类负荷间的耦合特性，提出了 CCHP 系统接入电网负荷随机模糊建模方法及其相应建模步骤。湖南省某市接入10 kV 的 CCHP 系统的历史负荷数据样本仿真结果验证了该模型的有效性和正确性。