适用于DC/DC 变换器的预测函数控制优化策略

针对使用预测函数控制(Predictive Function Control, PFC)的 DC / DC 变换器在负载切换时产生的扰动对变 换器响应速度有较大影响的问题,提出通过设计观测器观测扰动来优化预测函数控制算法的控制效果;相对于其 他提高系统抗扰动的方法,通过设计观测器来提高变换器抗扰动的方法的优点是实现简单、优化后控制效果好等; 设计 Luenberger 观测器对负载切换时产生的扰动进行观测,将观测值反馈给预测函数控制算法进行最优化分析, 并结合仿真结果对目标函数进行调整,优化后的目标函数能更好地响应扰动并尽快达到稳态;最后将优化后的控 制算法与 PI 双闭环控制方法进行比较,结果显示优化后的控制算法在受到扰动后比双 PI 控制方法动态性能更 好,实现了应对负载切换时提高系统动态性能的目标,增强了 DC / DC 变换器的抗干扰能力;优化后的算法只考虑 了负载切换时的扰动对于系统其他方面的扰动没有考虑进去,可以通过设计整个系统的观测器来进一步提高 DC / DC 变换器抗扰动的能力。

Prediction Function Control Optimization Strategy for DC / DC Converters

Aiming at the problem that the disturbance generated by the DC / DC converter using predictive function control PFC has a greater impact on the response speed of the converter during load switching it is proposed to optimize the control effect of the predictive function control algorithm by designing the observer to observe the disturbance. Compared with other methods to improve the system immunity the advantage of improving the converter immunity by designing an observer is to achieve simplicity and good control effect after optimization. The Luenberger observer was designed to observe the disturbance generated during load switching feed the observation value back to the prediction function control algorithm for optimization analysis and adjust the objective function in combination with the simulation results. The optimized objective function can better respond to the disturbance and reach a steady state as soon as possible. Finally the optimized control algorithm was compared with the PI double closed-loop control method and the results show that the optimized control algorithm has better dynamic performance than the dual-PI control method after being disturbed which achieves the goal of improving the dynamic performance of the system during load switching and enhances the antiinterference ability of the DC / DC converter. The optimized algorithm only takes into account the disturbance during load switching and does not take into account the disturbance of other aspects of the system and the ability of the DC / DC converter to resist disturbance can be further improved by designing the observer of the entire system.