Research On Transformer Modeling And Simulation Based On Improved J-A Hysteresis Model

With the rise of the construction of smart substations and ultra-large-scale converter stations,the safety and stability of power system operation is particularly important.Transformer is an important equipment in power system.Its safe and stable operation is of great significance to the power system.Therefore,it is necessary to study the electromagnetic transient process of transformer.Digital simulation of power system is an important method to study the transient process of power system.With the continuous improvement of system operation requirements,higher requirements have been set for the accuracy of power system simulation.At the same time,because there are many types of transformers,there are also large differences in the structure and operation of different types of transformers.Therefore,a refined general model that takes into account various characteristics of the transformer during operation is needed.The occurrences are simulated.Based on this,this paper proposes a transformer modeling method based on an improved J-A hysteresis model.This article first introduces the basic theory,related principles,and research status of the J-A hysteresis model,analyzes and demonstrates the model,and improves the deficiencies in the model.Then,different types of transformer models are studied,the relevant parameters in the models are processed,and the corresponding real-time inductance matrix is solved to obtain accurate transformer models.Finally,simulation experiments verify the accuracy of the model.The research content of this thesis mainly includes the following aspects:(1)Aiming at the traditional JA hysteresis model,it is an ideal model for ferromagnetic materials.This article considers the operating conditions of the iron core under actual working conditions,and adds the transformer iron core to the traditional JA hysteresis model to generate it during operation.The hysteresis loss,eddy current loss,and related stray losses are considered.At the same time,the influence of different manufacturing processes of the transformer core on the hysteresis characteristics of the transformer core is established.According to the actual situation,according to the principle of conservation of energy,the non-physical understanding of the model is analyzed and corrected.Compared with other iron core models,this model considers the electromagnetic characteristics of the iron core during the operation of the transformer from the actual situation,and dynamically reflects the various losses of the iron coreduring actual operation,which makes the model built closer to the real situation.Transformer core model in.(2)For different types of transformers,their structural operation modes are different,corresponding mathematical models of transformers are established,corresponding magnetic equivalent circuits are obtained according to the established models,and corresponding leakage flux models are established according to the transformer structure.The self-inductance of each core post and the mutual inductance between the core posts are obtained by the sum flux leakage model,and the corresponding real-time dynamic inductance matrix is established to avoid the ill-conditioned matrix involved in the solution process.Combined with the corresponding real-time dynamic hysteresis model of the transformer core,the equivalent permeability is solved,real-time inductance matrices of transformers with different structures are obtained,and a complete dynamic model of the transformer is established.Compared with other models,this model is simple from the principle of transformer and easy to calculate,without considering the complicated wiring mode of the transformer.(3)Considering the universality of the transformer model,the model in this article separates the leakage inductance parameters when calculating the inductance matrix.At the same time,according to the type of transformer,the transformer core parameters and inductance matrix parameters are updated in real time.The model is simple,the calculation speed is fast,and the use is convenient.The simulation model was used to verify the improved JA hysteresis model,single-phase transformer model,and three-phase multi-column transformer model.The model was compared with the existing model simulation to verify the reliability of the model.The potential application scenarios and application methods of the model are discussed further.