一种双相结构的同步Buck DC/DC变换器

Two-phase synchronous Buck DC/DC converter

指出了同步降压型直流-直流变换器从拓扑结构上实现软开关技术优点与在大功率场合下电流纹波大的特点,结合电感磁耦合技术将其扩展为双相结构的同步Buck型DC/DC变换器,分析了电感输出电流纹波减小的原理,并对不同负载下电路的工作特点进行了分析,采用可变频率的脉冲宽度调制控制方式以达到不同输出功率时的效率,试制了一台2kW的同步Buck DC/DC变换器样机,并给出了实验结果。变换器采用DSP芯片TMS320F2808作为控制管理芯片,通过积分分离数字PID算法改变控制量,具有较优异的动态性能,在蓄电池维护领域得到较好的应用。

The advantage of synchronous Buck DC/DC eonve/ter in implementing soft-switching by topology is pointed out,as well as its high current ripple in high-power application is indicated, Combined with the magnetic coupling technology,the single-phase synchronous Buck DC/DC converter is expanded into two-phase synchronous Buck DC/DC converter. The principle of reducing the inductor output current ripple is introduced and the operational characteristics are analyzed under different loads. The multi-frequency PWM （Pulse-Width Modulation） is applied to maintain the high efficiency for different power outputs. A 2 kW prototype is manufactured and the experimental results are presented. DSP TMS320F2808 is used to control the DC/DC converter and the control variables are adjusted by the integral-separation control algorithm. The designed converter has good dynamic performance and excellent application in storage cell maintenance.