The Optimized Design And Inductances Calculation Of Asynchronous Extra-High Voltage Synchronous Generator

The Asynchronous Extra-High Voltage Synchronous Generator(AEHVSG)is a new type of motor combined the advantages of Extra-High Voltage generators(EHVG)and asynchronous generators(ASG).AEHVSG can decouple active and reactive power,and realize variable speed constant frequency power generation.AEHVSG will not lose its stability when a large amount of reactive power is absorbed.At the same time,the stator output voltage is increased,which improves the efficiency and efficiency of power generation.AEHVSG is promising in the field of large clean power generation.First of all,according to the basic theory of electrical machinery,AEHVSG electromagnetic calculation is conducted and the body model data of AEHVSG are acquired based on extra-high voltage and asynchronized synchronous generator when considering rated data,the generator main dimensions,winding,magnetic circuit and magnetic field,parameter calculation.Meanwhile,the rationality of magnetic circuit design is verified under synchronous,sub-synchronous and super-synchronous speed,respectively.Secondly,the harmonic content of the air-gap flux density has a great influence on the motor performance,thus affecting the harmonic content of the terminal voltage of the AEHVSG.In order to reduce air gap flux density harmonics and improve the induced electromotive force waveform,the structure of AEHVSG is optimized in this paper.The stator winding of the AEHVSG employs round cross-linked polyethylene(XLPE),which produces a uniform distribution of the electric field,thus the rated voltage of AEHVSG arrive a high voltage.As a result,the stator structure has the characteristics of tooth length and groove depth,and the characteristics are not easy to change.In consequence,AEHVSG rotor structure is optimized.Air gap flux density harmonics and induced electromotive force harmonics are analyzed under different rotor winding connection and rotor slots,respectively.Finally,the winding wiring and rotor slots are determined.Finally,inductance coefficient are different at synchronous,sub-synchronous and super-synchronous speed,which will affect following researches such as AEHVSG excitation control inter-turn short circuit analysis of stator winding,inter-short circuit analysis.It is necessary to calculate inductance coefficient accurately under different conditions.In this paper,the inductive coefficient is studied according to magnetic conductance method without considering the effect of ferromagnetic saturation.In another word,the reluctance of the magnetic circuit does not change with the variation of flux density.The reluctance of the iron core is converted to the air gap.The air gap is amplified to consider the impact of core reluctance.Finally,the relationship between stator self inductance and mutual inductance with slip is confirmed.