Analytical modelling of salient pole synchronous generators under eccentricity faults by including stator slotting effect

Abstract

Abstract Here, a dynamic analytical model is provided for salient pole synchronous generators (SPSGs) under different eccentricity faults. A useful technique is developed first to describe the rotor position‐dependent non‐uniform air gap distribution by a proper function in the healthy state, which includes the stator slotting effect. Then, the exact air gap function is used along with the modified winding function theory to extract non‐integral equations for computing the SPSG various inductances that are playing critical role during analytical modelling and simulation of the machine. Afterword, the air gap function and the inductance equations are modified to include all types of the eccentricity fault. A 3 kW SPSG is simulated and then tested in laboratory under the healthy and the mixed eccentricity (ME) conditions. There are good accordance between the simulation and corresponding experimental results; they show that some harmonic components are introduced in the rotor and the stator currents due to the ME fault whose frequencies are integer multiples of the rotor speed frequency and whose amplitudes increase by increasing the fault severity. The load level change also affects the amplitudes of the harmonics.

Keywords

• fault diagnosis
• synchronous generators