Influence of Rotor Structure on Field Current and Rotor Electromagnetic Field of Turbine Generator Under Out-of-Phase Synchronization

Out-of-phase synchronization (OPS) fault may occur to the turbine generator used in gas-steam combined cycle units, which may seriously endanger the operation stability of the generator unit. To investigate the influences of rotor structure on field current and rotor electromagnetic field of a turbine generator under OPS, a 2-D field-circuit-grid coupled model (FCGCM) of the 150-MW turbine generator is established. By using the established FCGCM, the influences of rotor slot indexing number (RSIN) and magnetic permeability of the rotor wedge on field current under OPS of 180° were studied. A magnetic no uniform coefficient (MNC) was proposed to evaluate rotor magnetic field nonuniformity. The relations of the field current oscillation ratio and MNC to RSIN and magnetic permeability of rotor wedge were investigated. The results could provide a theoretical basis for the electromagnetic mechanism of the turbine generator under OPS faults.

[1]  D. Makuc,et al.  Computations of Magnetic Field Anomalies in Synchronous Generator Due to Rotor Excitation Coil Faults , 2013, IEEE Transactions on Magnetics.

[2]  A.M. El-Serafi,et al.  Effect of the main flux saturation on the transient short-circuit performance of synchronous machines , 2005, Canadian Conference on Electrical and Computer Engineering, 2005..

[3]  Heung-Ho Lee,et al.  A study on the detection of asynchronous state of the synchronous generator , 2013, 2013 International Conference on Electrical Machines and Systems (ICEMS).

[5]  Alessandro Franco,et al.  Combined cycle plant efficiency increase based on the optimization of the heat recovery steam generator operating parameters , 2002 .

[6]  Gordon W. Brown,et al.  Simulation for Design Purposes of Magnetic Fields in Turbogenerators with Symmetrical and Asymmetrical Rotors Part I-Model Development and Solution Technique , 1972 .

[7]  R. Romary,et al.  Non-Invasive Detection of Rotor Short-Circuit Fault in Synchronous Machines by Analysis of Stray Magnetic Field and Frame Vibrations , 2016, IEEE Transactions on Magnetics.

[8]  Liu Xiaofang,et al.  The influence of turbine generator rotor damping structure and material on first swing stability , 2015 .

[9]  Guan Chunwei,et al.  Calculation of a Complex 3-D Model of a Turbogenerator With End Region Regarding Electrical Losses, Cooling, and Heating , 2011, IEEE Transactions on Energy Conversion.

[10]  Ian Culbert,et al.  General Principles of Winding Failure, Repair, and Rewinding , 2004 .