针对现有的零电压软开关DC/DC变换器存在环流损耗大、占空比丢失严重、软开关范围窄和高频二极管寄生振荡严重等问题.设计了一种采用有限双极性PWM控制的零电压零电流软开关变换器,可在宽输入和宽负载范围内实现超前管零电流开通、零电压关断,滞后管零电流开关.采用RCD缓冲电路,有效抑制了高频整流二极管寄生振荡.相对于传统的零电压软开关变换器,具有环流损耗低、占空比丢失少和软开关范围宽等优点.
In view of problems with existing zero voltage soft switching DC/DC converters, such as large circulation loss, serious loss of duty cycle, narrow soft switching range and severe parasitic oscillation of high-frequency diodes, this paper designed a zero voltage zero current switching converter under limited bipolar PWM control. The converter could realize zero current turn-on and zero voltage turn-off for the leading tube and zero current switching for the lagging tube over a wide range of input and load. A RCD buffer circuit was adopted for effective suppression of parasitic oscillation of the high-frequency rectifier diode. Compared with the traditional zero voltage soft switching converter, the proposed converter had such advantages as low circulation loss, low duty cycle loss, and a wide range of soft switching.