一种新的简化负荷模型结构

New Structure of Simplified Load Model

好的负荷模型需要反映负荷的本质特征,并能够精确地仿真实测曲线。从系统辨识的角度来看,负荷模型是变电站大量电能消耗元件的一个等值模型,同时负荷模型具有参数不唯一的特点,这就使得简化负荷模型的辨识成为可能,负荷模型的简化辨识也会为工程实际应用带来方便。采用了ZIP负荷模型加感应电动机的综合负荷模型,针对我国配电网的特点,从参数灵敏度的角度出发,提出了将灵敏度小的感应电动机参数部分固定,仅辨识灵敏度较大参数的方法,并用残差分析指标对简化后的负荷模型的准确性加以验证,证明了简化模型参数的可行性,并为进一步研究辨识参数简化后的模型的统计学规律奠定了基础。

Load modeling is very important to power system analysis and control. However, due to the complexity of the load composition as well as its time-variable characteristics, load modeling is still a worldwidly unsolved problem. Among all the load model structures, the load model consisting of constant impedance, current and power in parallel with the motor is most widely used in power systems. However, there are too many parameters to be identified in this load model. From the identification viewpoint, the load model is only an input-output equivalent of various load components, so it＇s possible to minimize the identified parameters and simplify the load modeling process. Based on the sensitivity analysis of the load model parameters and the error analysis, a load model with less parameters to be identified is proposed, which simplifies the parameter identification process without losing the capability of the load model on describing the load dynamics. Case studies validate the feasibility of the simplified identification strategies.