Analysis and design of GTO current source inverter induction machine drive system with rotor frequency control

The GTO current source inverter (GCSI), a relatively new inverter topology, has several advantages over the conventional current source inverter (CCSI) such as a simple structure and nearly sinusoidal outputs. It is now replacing the CCSI for high power induction machine (IM) drives. However, the GCSI-IM drive system is a nonlinear, nonminimum phase and high-order system. The analysis and design of such a system are quite complex.; In this thesis, a comprehensive approach for analysis and design of the GCSI-IM drive system is developed. Steady state and dynamic behavior of the system with constant rotor frequency control is thoroughly investigated.; A dynamic model suitable for the drive system analysis and design is established. Based on this model, a steady state model is derived. Steady state characteristics of the system are investigated. A phenomenon of static instability associated with steady state operating conditions is identified. Two types of current feedback schemes for the drive system are studied and a high frequency instability problem related to stator current feedback is investigated. A systematic design procedure for current and speed control loops is developed. A detailed design example for the GCSI-IM drive system is presented.; Various analytical tools are developed and employed for the analysis and design of the nonlinear, nonminimum phase and high-order drive system. A small signal model of the drive system is developed for dynamic analysis. Root locus method is used to design compensators. Eigenvalue analysis is employed for system stability studies. Eigenvalue sensitivity analysis is performed to gain greater insight into the drive system dynamic behavior. A time domain simulation program is developed to verify the s-domain design.; Experiments on an 800hp GCSI-IM drive system are conducted. The steady state and dynamic tests including a stability boundary test are carried out. All the theoretical work including the s-domain design and the time domain simulation is experimentally verified.