Reconfigurable Star-Delta VBR Induction Machine Model for Predicting Soft-Starting Transients

Induction machines are extensively utilized in many commercial and industrial applications. Simulations of such machines to analyze their starting and operational performance require numerically accurate and efficient models. The conventional qd models, although simple to implement, require snubber circuits for interfacing with an external network, which reduces the accuracy and makes the model computationally expensive. This paper extends the prior work and presents a reconfigurable star-delta constant-parameter voltage-behind-reactance (CPVBR) model of a three-phase squirrel-cage induction machine considering the low-frequency deep-rotor-bar phenomenon. The eigenvalue analysis and computer studies demonstrate that the proposed model yields superior computational performance while providing an efficient machine-network interface as compared to the established qd model. It is envisioned that the new model can be useful for efficient simulation of power systems including induction machines with star-delta starters.