Research On Saturation Of Sychronous Generator On Various Operation Conditions Considering Effects Of Multiple Factors

Theoiy analysis and finite-element calculation were combined in this paper to study saturation considering effect of multiple factors and cross magnetization phenomenon in synchronous generator in normal and abnormal operations. The basic method of calculating magnetic field and parameters and series measures of improving precision considering saturation effected by multiple factors and cross magnetization phenomenon in various operations were studied. On Basis of abOve research, the rule of saturation characteristic, power angle characteristic and operation parameters considering saturation effected by multiple factors and cross magnetization phenomenon versus operation conditions were thoroughly researched. The main results of research in this paper are: 1 The basic method of calculating magnetic field and parameters considering saturation effected by multiple factors and cross magnetization phenomenon were determined by studying different methods of calculating magnetic field and parameter and factors effecting calculation precision. The results of calculation were proved by comparison with field test data. 2 The essence of saturation that is effected by multiple factors were discovered, a concept of d-axis current ratio was introduced, the rule of air-gap e.m.f versus resultant current, power angle and d-axis current ratio was found. Taking 3 00MW turbine generator as an example, the saturation curves family of d-axis, q-axis and any position were obtained for the first time. 3 In aspect of rule of parameters versus operation conditions, the rule of basic reactances (x x.. Xdq Xqq x and Xqd) versus power angle, terminal voltage, field current and air-gap e.m.f. was found. 4 Based on the study of electromagnetic torque calculation methods, series measures of improving calculation precision when using different methods were determined. The relative curve family was obtained for the first time. The relationship between power angle characteristic, steady state stability and the operation parameters, operation conditions considering saturation effected by multiple factors and cross magnetization phenomenon was found. 5 In order that the above rule and data table can be used in practical application, artificial neuron network (ANN) was adopted to estimate the field current, power angle and saturation parameters. Genetic algorithm and object-oriented method were combined into object-oriented genetic algorithm. The new algorithm was used to design and train ANN. The results of application show that the relationship between field current, power angle and other operation parameters of synchronous generator and operation conditions, which was established by ANN, offered a powerfttl measure for application of results of this paper.