| Power electronic transformer(PET)is an intelligent electronic equipment which combines modern power electronics technology with transformer technology and power conversion technology.Power electronic transformer can not only be used as traditional power transformer,but also has the function of flexible control of input current and output voltage.Compared with traditional transformer,it also has the advantages of high power density,flexible and diverse interfaces,good controllable performance and so on,so it is widely used in smart grid,track traction system and other circuits.DC-DC conversion link is power One of the indispensable links in electronic transformer,the function of this part of circuit is to realize the function of electrical isolation and energy transmission.Based on the development of modern power industry,this paper briefly introduces the application background and research status of double active full-bridge bidirectional DC-DC converter(DAB),and shows its development prospect as the core circuit in distributed power supply grid-connected and power electronic transformer.The typical DAB topology single phase shift,double phase shift control strategy and hybrid bridge bidirectional DC-DC converter control strategy are studied emphatically.According to the advantages and disadvantages of each circuit topology,the power transmission,soft switch and power reflux of the converter are deeply analyzed and contrasted.Due to the mismatch of the voltage at the output side and the input side,the mixed bridge is used instead of its original full-bridge circuit to improve the matching of the input/output voltage and solve the problem that the peak current of the converter is too high and the ZVS range is limited. |
PDF Full Text Request