Stator flux estimation from inverter switching states for the field oriented control of induction generators

A study of stator flux estimation from inverter switching states for the stator flux-oriented control (SFOC) of induction generators for power generation application is presented. After reviewing the main drawbacks of the rotor flux-oriented control (RFOC) system for the above-mentioned application, stator voltage reconstruction from inverter switching states and methods of stator flux estimation and implementation issues are described. SFOC algorithm is implemented with the proposed estimation technique using a digital signal processor. Tests are conducted on a 200 hp induction generator and the dynamic and steady state performance of the generator control system are presented.