Electrical Energy Quality Perturbation To Largescale Turbogenerator Influence And Analysis

The large-scale generator is the electrical power system core,is extremely important and the expensive equipment,its movement reliability to the system normal operation and the guarantee electrical energy quality down to the entire society's safe handling all is playing the extremely vital role.Large generating units will be subject to the impact of various special operation and faults.It has very important theoretical value and practical meaning in engineering to make deep calculation and analysis on the transient behaviour of power system under disturbances.Systematic analysis for transient processes of machines and the power system touch upon mesh equation , electric machine equations ,mechanical equations of shaft system,which is complicated.Taking two typical disturbances as three phase sudden short circuit and harmonics as examples,the dissertation has a study on transient behaviour of machines and the power system under disturbances.In this dissertation,the influencese on the characteristic of the typical electric power --turbo generator under non ideal conditions such as three phases unbalance and harmonics.Through the turbogenerator concrete structure and the movement characteristic analysis,synthesizes the domestic and foreign research results as well as correlation research foundation in many years, from the magnetic field theory,to analysis and calculate magnetic field situation in the different electrical energy quality situation.The transient electromagnetic field of turbogenertor are calculated by time-stepping finite element method under three phase sudden short circuit.The harmonic components of short circuit current are analysed,the transient stator current and transient parameters are derived with the rotor damping systems simulated by one two circuits.Finally,taking a 600MW turbogenerator as an example,the method of determining the transient reactances and time constant is presented. In addition , according to the electrical network harmonics characteristic,Changes using Fourier to it carries on the separate analysis to it,has calculated the harmonics to the motor-field influence.