The Analysis And Research Of The Synchronous Generator With Rectified Loads

The synchronous generator with rectified loads is widely used in power systems, such as the electric propulsion of ship, postal communication, airplane and so on, where high-quality DC power should be supplied. And it is studied by many scholars. The main fields of the research involve the digital simulation, the mathematical models, the steady-state performance and the stability analysis.The paper makes an in-depth study of the synchronous generator model in the MATLAB/Simulink, and its flaws are pointed out. Based on the flaws and the need of research in the paper, the stator and rotor decompounded state equations of synchronous generator are proposed. A new model which based on the equations is established by MATLAB, which will been used for analysis and research of the synchronous generator with rectified loads. And the modularization of the model is realized.The steady-state performance of synchronous generator rectification system is analyzed. Simulation model of the system is established with the new model. The new model can easily be changed into the model of steady-state performance with the three-phase unsymmetrical loads, which is deduced under neglecting resistance of rotor. The formulas of analytic method are obtained according to the model, the analytic calculation steps and the detailed calculating process by program are given, which is used directly for project application. Compared with the simulation results, the accuracy of the analytic method is verified. The fact that neglecting the affection of rotor resistance brings some differences has been proved by simulation. But neglecting the differences is permitted when the stator resistance is in the natural value.The stability of synchronous generator rectification system with Back-EMF load is studied by simulation. The affection of all parameters of the system on system stability is observed by simulation. To solve the long computing time in simulation, the stator of the decompounded model and rectifier are modified according to commutation formulas in steady state, and the simplified model is obtained. The results of the two models are accordant by simulation calculation. Base the simplified model, both the speed of computing is higher, and the duration of commutation and its harmonic are approved not to have influence on the stability of the synchronous generator rectification system.