开关变换器多频率控制方法研究

提出并研究了一种新颖的开关变换器控制方法——多频率(multifrequency)控制方法。该方法在每一个开关周期结束时刻采样输出电压,对其所处的电压区间进行判断,并由此采用相应频率的不同控制脉冲对开关变换器进行控制,以调整变换器输出电压。多频率控制方法具有控制算法简单、开关变换器稳定性好、瞬态响应速度快、电磁干扰噪声小、轻载效率高等优点。相比于双频率控制,多频率控制不仅可以拓宽开关变换器输出功率范围,还可以降低开关变换器输出电压纹波。实验结果验证了理论分析的正确性。

Investigation of Multifrequency Control Method for Switching Converters

Multifrequency control method, a novel control method for switching converters, is proposed and investigated in this paper. The control pulse with different frequency which is determined according to the voltage intervals of the sampled output voltage at the end of previous switching period is applied to regulate the output voltage. In contrast to bifrequency control, the multifrequency control not only extends the output power range, but also reduces the output voltage ripple; it has merit of simple control algorithm, strong stability, fast dynamic response, low electromagnetic interference (EMI) noise, and high efficiency at light load. Experimental results demonstrate the correctness of the theoretical analyses.