For the case with electrolytic capacitors as the output capacitor, the traditional capacitor current hysteresis (CCH) controlled buck converter is always in over-damping state due to the ESR, and has a poor dynamic performance. Moreover, there is a problem of variable switching frequency operation in the CCH controlled buck converter. To solve these problems, an improved constant-frequency CCH (CF-CCH) control scheme using the reconstructed ideal-capacitor voltage is proposed in this paper. The ideal-capacitor voltage is reconstructed through a low-pass filter and an integrator, and introduced into the control loop to replace the actual output voltage. In the proposed CF-CCH control scheme, the damping ratio is designed as the optimum value 0.707, which is in under-damping state. Furthermore, the switching frequency is kept constant by disturbing the hysteresis bands with a pair of periodic ramp signals. In addition, the circuit design of the proposed CF-CCH control scheme is presented. Finally, the validity and superiority of the proposed CF-CCH control scheme are verified by simulation and experiments.

中文翻译：

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利用重构理想电容电压对降压变换器进行恒频电容电流滞环控制


对于采用电解电容作为输出电容的情况，传统的电容电流滞回(CCH)控制降压转换器由于ESR的原因始终处于过阻尼状态，动态性能较差。此外，CCH控制降压转换器中存在可变开关频率操作的问题。为了解决这些问题，本文提出了一种使用重构理想电容器电压的改进恒频CCH（CF-CCH）控制方案。通过低通滤波器和积分器重构理想电容器电压，并将其引入控制环路以代替实际输出电压。在所提出的CF-CCH控制方案中，阻尼比设计为最佳值0.707，处于欠阻尼状态。此外，通过用一对周期性斜坡信号扰乱磁滞带，开关频率保持恒定。此外，还介绍了所提出的CF-CCH控制方案的电路设计。最后，通过仿真和实验验证了所提出的CF-CCH控制方案的有效性和优越性。