考虑频率特性的感应电动机负荷模型的对比研究

以往主要研究负荷的电压特性,很少研究频率特性。而在小电网或者薄弱电网频率可能有明显变化,所以需要研究电力负荷的频率特性。给出考虑频率特性的五阶电动机负荷模型和新三阶实用电动机负荷模型,提出两种负荷模型的参数辨识方法,通过蚁群算法辨识其中的重点参数。结合仿真算例,分别对比考虑和不考虑频率变化时的五阶电动机负荷模型、新三阶实用电动机负荷模型,还对比了两种负荷模型。根据新疆电网的实际扰动数据,对考虑频率特性的必要性进行了校验,结果表明,考虑频率特性所得参数辨识结果更精确、拟合效果更好,考虑频率特性时五阶电动机负荷模型效果更好。

Comparative study of the induction motor load models with and without considering frequency characteristics

Previous studies mostly focused the voltage characteristics of load rather than the frequency characteristics. The frequency may vary obviously in the small or weak power grid, so the frequency characteristics should be studied. The fifth-order induction motor load model and the new third-order practical induction motor load model are given. A method for load parameter estimation is proposed, i.e. estimating the key load parameters through ant colony optimization (ACO). In a simulation case, the identification results of two load models are compared with and without considering frequency characteristics. Finally, the measured data under a disturbance in Xinjiang Power Grid are used to validate the necessity of considering frequency characteristics. It is indicated that the load parameter estimation and simulation results with considering frequency characteristics are better than that without considering frequency characteristics, and the fifth-order induction motor load model is better than the new third-order practical induction motor load model.