Research On Bridgeless PFC Circuit Based On Planar Integration Technology

With the advent of the electrical information age,power electronics technologies develop rapidly.In the modern power electronics,especially the switching power supplies,the smaller size and the lighter quality become a popular trend.As we known,power factor correction(PFC)circuits get wide application in the switching power.However,there are many issues in this circuit,as low power density and instability by the distributed parameters at high frequency,since it uses many large passive components.The contribution of this paper is to solve the above problems and achieve the same performances,meanwhile it increases the power density of the bridgeless PFC converter.By using a new planar integration method,the purpose of this paper is to increase the power density of the bridgeless PFC converter since it uses many large passive components.The main tasks of this paper include the following aspects.(1)The first thing is to determine the performance indexes for a 1 kW bridgeless PFC circuit.Then,the parameters of the main circuit are designed.For the parameters design of the EMI filter at the front end of the main circuit,the insertion loss(IL)is used.The modeling analysis is carried out which it includes the analysis for the common mode and differential mode respectively.Under ideal state,the equivalent circuits for the common mode(CM)and the differential mode(DM)are established.Then,the corresponding relation matrix for the two-port network is established.By using MathCAD,the values for the passive components can be get when the matrix are iterated into the IL formula.(2)Based on the(1),this paper presents a new integrated structure for the passive components in the bridgeless PFC circuit.By using the plane PCB integration technique,the passive components,such as EMI filter and Boost inductor are integrated into an E-E-E core.The CM inductors,the DM inductor and the boost inductors are realized by several copper foils when these foils are placed in the differential legs of the magnetic core.With the ceramic dielectric between the two-copper foils,the integrated capacitor is formed which is used for the CM capacitors and the DM capacitors,respectively.The explosion and synthesis diagrams of the integrated structure are presented with SolidWorks.And the connection mode of the integrated structure is exhibited.The prototype is fabricated according to the design.The feasibility of the planar integrated structure is verified.(3)The experimental platform for 1 kW bridgeless PFC converter is built.According to the performance indexes of bridgeless PFC converter,the PCB circuit board is made by using Altium Designer.Then,the circuit board has been debugged.Finally,the size and performance of the discrete components and the integrated prototype are compared.It proves the proposed integrated structure can increase the power density of the bridgeless PFC converter significantly.