基于扩张状态观测器的移相全桥变换器无模型预测电流控制

Model-Free Predictive Current Control for Phase-Shifted Full-Bridge Converters Based on Extended State Observer

针对移相全桥变换器易受到外部扰动导致控制性能下降的问题,提出一种基于扩张状态观测器的移相全桥变换器无模型预测电流控制策略(ESO-MFPCC)。建立变换器不依赖系统参数的超局部模型,替代原有复杂精确模型;设计扩张状态观测器估计超局部模型中的干扰部分,引入占空比补偿环节,削弱换流过程中产生的固有占空比丢失影响,提升系统的控制精度;离散化系统预测模型,结合无差拍控制策略,输出最优等效占空比。实验结果表明,该控制策略具有良好的鲁棒性和动态性能。

Aiming at the problem that the control performance of phase-shifted full-bridge converter was vulnerable to external disturbance,a model-free predictive current control strategy based on extended state observer was proposed.An ultral-local model independent of system parameters was established to replace the original complex model.An extended state observer was designed to estimate the unknown part of the ultral-local model.Duty cycle compensation was introduced to reduce the effect of inherent duty cycle loss by the converter current process and improve the control precision.The predictive model of the system was discretized,and the optimal equivalent duty cycle was calculated with deadbeat predictive control strategy.Experimental results show that the control strategy has good robustness and dynamic performance.