宽输出适应的兆赫兹高效率高功率密度DC-DC变换器研究

High Efficiency High Power Density MHz DC-DC Converter for Radar Power Supply System

对于雷达电源系统中高压转低压的DC/DC应用场景,目前基于高压硅器件的方案受制于器件寄生参数的影响,开关频率一般在数百kHz以内,难以进一步提升效率和功率密度。文中利用NFoM较低的低压硅器件,提出了利用低压电路单元链式串并联的方法以实现更高电压的功率变换,该方法能够适应雷达电源系统多种输入输出电压变换需求,并且在MHz开关频率下能够实现较高的效率和功率密度。最后以380 Vdc/48 Vdc的应用场合为例设计并实现了实验样机,实现了98.0%的峰值效率,在1 800 W的满载功率下,样机的功率密度超过800 W/in^(3)。

For the high-voltage to low-voltage DC-DC application in the radar power supply system, restricted by the large parasitic parameters, the switching frequency of the current solutions using high-voltage silicon devices is generally within hundreds of kHz, which makes the efficiency and power density difficult to be further improved. In this paper, low-voltage devices with low NFoM are used and a method of using low-voltage circuit unit in series and parallel to achieve higher voltage power conversion is proposed, which can adapt to the various input and output voltage conversion requirements. Besides, the switching frequency of converter using the proposed method can be improved to MHz while high efficiency and high power density can be achieved at the same time. Finally, a 380 Vdc/12 Vdc prototype is designed and implemented for verification, a peak efficiency of 98.0% is achieved and the power density of the prototype achieves more than 800 W/in^(3) under a full load power of 1 800 W.