Modeling and Self-Excitation Analysis of Split Cascade Brushless Excitation Pulsed Alternator System

Aiming at the problem that self-excitation of air-core pulsed alternator using brush and slip ring reduces the system life and reliability, a split cascade brushless excitation pulsed alternator is studied in this article. First, the structure and working principle of the system are analyzed, and a dynamic mathematical model is established under natural coordinate system, considering the mutual inductance of the winding and the electromechanical energy conversion relationship. The correctness of the model is verified by field-circuit coupled finite element method. Second, the self-excitation process of the complex system is studied, and the influence mechanism of thyristor commutation is analyzed. The relationship between the self-excitation critical speed and the system parameters is deduced theoretically and verified by the established model. The results show that compared with the field-circuit coupled finite element method, the dynamic mathematical model has higher computational efficiency and flexibility of parameter adjustment. Considering the influence of nonideal factors, the calculation of self-excitation critical speed has higher accuracy and is instructive for the preliminary parameter design of the system.