Salient Pole Synchronous Generator Optimization by Combined Application of Slot Skew and Damper Winding Pitch Methods

Abstract

Slot skew is applied as a method to increase the armature winding voltage waveform quality of synchronous hydro generators. Skew that matches the region of one slot pitch can effectively damp stator slot harmonics. However, achieving this condition can be difficult in some manufacturing cases, especially for the machines with greater axial length. That is why other methods are commonly used to increase the voltage waveform quality of large hydro generators. One such method is based on the damper winding slot pitch choice which ensures reduction of stator slot harmonics from the main magnetic field. Appropriate placement of damper bars over the pole shoe does not represent a significant technological problem and is much simpler to manufacture in compare with the slot skew or the fractional armature winding methods. The downside of damper slot pitch adjustment method is the damper bar currents incensement in steady state condition of the generator, which increases damper winding losses and also the rotor temperature. In order to decrease damper winding current for long term operation and enable the generator pole shoe design with smaller cross section damper bars, a combination of damper slot pitch and partial slot skew can be utilized. This paper gives insight on consequences that can occur for voltage waveform if slot skew does not not fully match the stator slot pitch and the advantages of above mentioned combined method for the design optimization of salient pole synchronous generator.

Using grey wolf optimizer to minimize voltage total harmonic distortion of a salient-pole synchronous generator

“…There are also remarkable studies those are discussed the effect of damper winding on the SG in their studies [19][20][21][22][23][24][25][26].…”

Rotor design optimization of a synchronous generator by considering the damper winding effect to minimize THD using grasshopper optimization algorithm

“…They used FEM for the simulations. Elez et al [19] presented a study on optimization of salient-pole SG. To that end they combined slot skew and damper winding pitch methods.…”

Design Improvement of a 2 Mva Synchronous Machine by Using Particle Swarm Optimization

“…It has been concluded that with this optimization method, the damper bar losses can be reduced by 7 times and the total harmonic distortion can be reduced below 1%. [5]. In [1], the shape of the rotor is optimized to facilitate the assembly of excitation windings.…”