一种适用于软开关全桥PWM变换器的非线性控制新策略

A New Nonlinear Control Method for Soft Switching Full Bridge PWM Converters

提出一种适用于软开关全桥PWM变换器的非线性控制新策略,通过引入一个非线性积分器,强制开关变量的平均值在每一个完整的开关周期中严格等于控制基准,彻底解决了因电力电子器件开关时间导致的开关误差,实现了开关变换器在输入电源变化时的零稳态误差。利用带双前馈补偿网络的控制器,变换器对负载扰动的抑制能力和动态响应显著改善。准周期积分函数控制的全桥PWM变换器具有高线性、大动态范围、极好的扰动抑制和鲁棒性。新策略还具有良好的通用性,适用于各种硬开关或软开关方式的Buck变换器、Cuk变换器或半桥变换器,以及由他们派生出来的其他变换器。仿真结果证明了新方案的合理性和有效性。

A new nonlinear control method for Full-Bridge Zero-Voltage and ZeroCurrent Switching PWM Converter is proposed to control the dutyratio of a switch such that in each whole cycle the average value of a switched variable is exactly equal to the control reference. The controller can correct switching errors thoroughly in one switching cycle. There is no steadystate error when the power source voltage is perturbed. The double feedforward compensation provides fast transient response for load disturbance. The proposed method can get the excellent performance in power source perturbation rejection and following the control reference. The proposed method is very general and applicable to most types of PWM, resonant based, or softswitched switching converters.