华 中 科 技 大 学 硕 士 学 位 论 文
Abstract
MATLAB has been the chief computer simulation platform in the field of electric
machinery and electric automation, due to its advantages of powerful matrix and numerical
computing, outstanding visual data processing and richer simulation model library. It's
obviously that exploring effective modeling and simulation methods of electrical machine
dynamics based on MATLAB will make a significant sense. A lot of research is conducted
to investigate the modeling methods of non-library models and complex control systems in
this paper, and user-defined model library is established to improve simulation efficiency.
Firstly, taking induction machine as an example, a new way of building and packaging
non-library models by using S-function is probed and the process of modeling is simplified
greatly compared to using modules. The phenomenon that speed appears negative when
induction machine starts with load in simulink is studied and a reasonable solution is given;
then an improved induction machine model in which rotational inertia changes with load is
proposed by introducing the concept of non-stationary parameters. The new simulation
model is more accurate, and flexible and effective modeling methods are provided.
Secondly, the transformation of mathematical model to simulation model for complex
electrical machine dynamics is presented based on the research of induction machine
VVVF starting model, VC system and DTC system, that is, the model should be devided
into several subsystems according to its principle and funtion, then subsystems are builded,
packaged, tested and organized. Following that, a series of control systems are analysed and
simulated by using method mentioned above, such as the SVPWM controlled PMSM, DTC
system of PMSM, double closed-loop speed control system of BLDCM and BLDCM DTC
system. The simulation results prove the flexibility and validity of the method, and provide
technical reference for the application of electrical machine dynamics simulation in
mechanical-electrical integration system.
Finally, aiming at the shortage of the MATLAB model library, non-library models
builded and packaged in MATLAB/Simulink platform are summarized, they are integrated
and added to user-defined model library to enrich and consummate MATLAB model library,
so that users can call the models directly and simulation efficiency is improved.
Keywords:
Electrical machine dynamics, Digital simulation, Modeling method, S-Function,
Module packaging
