Stability Assessment of Isolated Power Systems with Large Induction Motor Drives

Induction motor drive systems may notably affect the dynamic behavior of electric power systems, especially in cases in which large motors load are an important percentage of the total system load. In order to assess stability and dynamic performance, an appropriate model is needed. This paper first presents a fundamental frequency model of induction motors drives with PWM converters. The model is fully compatible with modeling assumptions in power system stability analysis, and thus can be readily implemented in power system simulator software. A full switched and electromagnetic transient model is used for validating purposes. The proposed model provides adequate accuracy for transient and dynamic stability analysis and is efficient with regard to calculation time. Besides, different aspects related to the stability of isolated power systems with large induction motor drives are discussed in the paper.