MODELING AND CONTROL OF A MULTIPHASE INDUCTION MACHINE WITH STRUCTURAL UNBALANCE .1. MACHINE MODELING AND MULTIDIMENSIONAL CURRENT REGULATION

The multiphase winding structure provides an induction machine with ca pabilities of starting and running even with one or more of its stator phases open-circuited However, when operated with such a structurally unbalanced condition, the dynamic properties of the machine will chan ge drastically from its balanced operation condition. For example, fie ld-oriented control strategies developed for a balanced winding struct ure will no longer function properly and could lead to catastrophic co nsequences. In this paper, a unified approach to the modeling and fiel d-oriented central of dual three phase induction machine with one phas e open is presented. Using the concept of vector space decomposition, the proposed technique is established on the basis of the asymmetrical winding structure directly, and thus provides a precise, physically i nsightful tool to the modeling and control of induction machines with structural unbalance.