Nonlinear Control Of PWM DC-DC Boost Power Converters

In recent years, with the rapid development of power electronics, switching power converters have been extensively applied in various fields, and the requirements of the performance of the switching power converters are increasing. Required switching power converters with high-quality output waveform, whose quality includes following two aspects:good dynamic performance and high steady-state accuracy. Therefore, the study of a simple control strategy on switching power converters with excellent dynamic and static performance has become one of the hot issues in power electronics and automation.In this thesis, considering the physical characteristics of PWM DC-DC Boost power converters system, we give the average state-space model according to their "on" and "off" stage. In order to obtain the high-performance of power converters, we apply nonlinear control method to design controllers based on the average state-space model.Firstly, according to the average model of Boost converter, we design a controller with standard backstepping method. Due to the special structure of Boost converter, the controller designed is a dynamic controller. However, simulation results are given to show its effectiveness.Secondly, the standard backstepping method is improved by introducing some class K functions to parameters of the controller designed with the standard backstepping method. Thus, the parameters of controller are connected with the error information. Then, the dynamic performance and the adaptability are enhanced.Finally, based on the improved backstepping method, we design the adaptive backstepping controller under the circumstance of the load value unknown. And based on the model with the parameter uncertainty, we design the backstepping controller respectively. In the end, we make some comparisons on various aspects through simulation, to show their effectiveness, superiority and robustness.