摘要
反激变换器是LED驱动的常用拓扑,为了降低成本,减小光耦对于LED电源可靠性的影响,提高系统的控制性能,同时避免线性控制方式在启动时的输出过冲造成LED损坏,提出了一种通过控制原边电流间接控制输出恒流的非线性控制策略。根据无源性控制理论建立了反激变换器的欧拉拉格朗日模型,验证了系统的无源性,获得反激变换器原副边电流关系,然后基于无源性理论和Layapunov稳定性理论,推导出系统的无源性控制规律。这里所提出的控制方法结构简单,成本低,可靠性高,控制性能良好。实验结果验证了该控制方法的正确性,采用原边非线性电流控制方法的反激变换器具有稳定的输出电流,恒流精度高,启动无过冲并且具有良好的动态响应。
Flyback converter is the common topology for LED driver. In order to reduce costs, reduce the influence of opti- calcoupler on the reliability of LED power supply, improve the control property of the system and avoid the LED damage caused by output overshoot when the linear control mode is started, a nonlinear control strategy which can indirectly control output con- stant current by controlling the primary current is proposed. Euler-Lagrange model of the flyback converter was established to ver- ify the passivity of the system based on passivity-based control theory, the relationship between the primary current and output current was obtained, and then the passivity-based control rule was deduced base on passivity theory and Layapunov stability theory. The control method proposed in this paper has advantages of simple controller structure, low cost, high reliability and good control performance. The validity of the control scheme was verified by test result. The flyback converter controlled by pri- mary nonlinear current control method has a stable output, high precision and exellent transient response, and no overshoot when startup as well.
出处
《现代电子技术》
2013年第6期164-166,170,共4页
Modern Electronics Technique
关键词
反激变换器
原边电流控制
无源性
非线性控制
flyback converter
primary-side current control
passivity-based control
nonlinear control
