交错并联磁集成DC-DC变换器的控制策略研究

Research on Control Strategy of Interleaved Parallel Magnetic Integrated DC-DC Cconverter

摘要:

为提升交错并联磁集成DC-DC变换器抗干扰能力及均流效果，设计一种由线性自抗扰和比例积分调节器串联的控制策略。通过建立交错并联磁集成DC-DC变换器模型，分析其工作模态，建立小信号模型推导变换器传递函数；设计电流内环为比例积分均流解耦控制，防止因为相电路参数差异可能引起相间不均流问题，影响到整个变换器的运行可靠性，电压外环为线性自抗扰控制，提升系统抗干扰能力，通过设计扩张状态观测器和线性状态误差反馈控制器实现对系统的高精度控制；在matlab/simulink中对传统PI双闭环控制策略和提出的LADRC-PI解耦均流控制策略进行仿真验证对比，并搭建实验平台进行样机实验。仿真结果和实验结果表明所提控制策略有更强的抗干扰能力和均流能力。

Abstract:

To improve the anti-interference capability and current-sharing performance of interleaved parallel magnetic integrated DC-DC converters, a control strategy combining linear active disturbance rejection control (LADRC) and proportional-integral (PI) regulator in series is designed. By establishing a model of the interleaved parallel magnetic integrated DC-DC converter, its operating modes are analyzed, and a small-signal model is developed to derive the converter's transfer function. The current inner loop is designed as PI current-sharing decoupling control to prevent uneven current distribution between phases caused by parameter differences, which could affect the overall reliability of the converter. The voltage outer loop employs LADRC to enhance the system's anti-interference capability. A high-precision control system is achieved by designing an extended state observer (ESO) and a linear state error feedback (LSEF) controller. In matlab/Simulink, simulations are conducted to compare the traditional PI dual-loop control strategy with the proposed LADRC-PI decoupling current-sharing control strategy. An experimental platform is built to perform prototype tests. Both the simulation and experimental results demonstrate that the proposed control strategy exhibits stronger anti-interference capability and improved current-sharing performance.