摘要
由于开关状态的时变特性,Super-Boost变换器是一个高阶非线性系统,交流小信号模型存在右半平面零点,为非最小相位系统。因此,采用传统的电压或电流控制方法时,控制器的设计变得十分困难。而传统的滑模控制由于存在开关频率不确定等问题,不适用于需要固定开关频率的场合中。针对这个问题,提出一种改进的基于PWM调制的滑模控制方法,首先以开关状态为控制信号对系统进行建模,其次,在验证传统滑模控制的稳定性和状态轨迹的收敛性后,考虑到实际系统中的未建模部分,在等效控制律的基础上加入离散分量共同构成滑模控制律,并对系统稳定性和鲁棒性进行理论分析。最后,通过与电压控制方式下的仿真和实验结果进行对比,当滑模系数λ=104时,系统响应速度能提升50%,并且系统参数在±25.64%内变化时有较好的鲁棒性。
Super-Boost converter becomes a high-order and nonlinear system due to the time-varying characteristics of switch state. There exists right half plane zero of the AC small signal model, which is not a minimum phase system. It is difficult to design the controller when applying the traditional voltage or current method. Because of some problems such as uncertainty of switching frequency, the occasion of fixed switching frequency is not appropriate in the traditional sliding mode control. To solve this problem, an improved sliding mode control method based on PWM modulation is proposed. Firstly, switch status is taken as the control signal when the system is modeled. Secondly, it is essential to verify the stability of the conventional sliding mode control and the convergence of state trajectory. Thereafter, the unmodeled part of actual system is considered. So the discrete components are added to the equivalent control law, which constitute the whole sliding mode law. Then the stability and robustness are analyzed. Lastly, compared with the simulation and experimental results of voltage control mode, the response speed can increase by 50% and the system will be robust when the parameters change within the range of ±25.64% when the sliding mode coefficient λ=104.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2016年第10期3051-3058,共8页
High Voltage Engineering
基金
国家自然科学基金(61403274)~~
