一种改进的电动机静态聚合方法

Improved static aggregation of induction motors

电动机参数是电力系统电压稳定、暂态稳定的关键因素之一。在基于统计综合法的负荷建模中,如何提高电动机参数的聚合精度是重要课题。针对传统电动机聚合方法没有考虑聚合前每台电动机稳态滑差的不足,提出了一种改进的电动机的静态聚合方法。该方法首先根据聚合前各电动机的惯性时间常数、暂态电抗、转子回路时间常数、临界滑差定义了一个电动机的特性指标,并按照该指标对电动机进行分组。然后将每组中的电动机根据其稳态等值电路转化为3种阻抗并联的形式,在对3种阻抗分别聚合后再还原为一台电动机稳态等值电路。算例表明该方法能够有效提高仿真精度。

The parameters of induction motors are critical to the voltage stability and transient stability of power system and the accuracy of induction motor aggregation is the basis of component-based load modeling. As the traditional static aggregation approach of induction motors does not consider the steady slip before aggregation,an improved approach is proposed. It defines a performance index according to the time constants of inertia,rotor circuit and transient reactance and the critical slip of each induction motor before aggregation,and then groups the motors according to the index. Each motor group is transferred to the paralleled form of three impedance kinds according to its steady equivalent circuit,and the impedance of each kind is then aggregated. By transferring back from three aggregated impedance kinds,the steady equivalent circuit of an equivalent motor is obtained. A simulative example shows its aggregation accuracy.