Research On A Novel Power Electronic Transformer And A Dc Interface Circuit

As an important part of smart grid, power electronic Transformer( PET) has many advantages, such as small volume, light weight, low cost, high quality energy, working in four phases, intelligent control and so on,which make it meet the requirement of strong smart grid and get great social benefits and economic benefits. Now, PET has already got a widely research, but it doesn’t have many applications. The fact that smart grid and distribution grid develop fast makes PET more important in future. Because the requirement of reality, the research on PET and DC interface circuit has great theory sense and reality meaning when the new energy inserts to grid or the smart grid improves.1) Analyzing the improvement of PET and DC-DC converter, especially the four-phase PET with decompression type backing circuit and bidirectional DC-DC converter, including power circuit, modulation algorithm and control strategy, getting the existing problem and performance requirement and confirming the research strategy.2) Analyzing the circuit construct and four-phase working theory of PET applying current source rectifier, including current source rectifier, high frequency inverter, high frequency transformer, controlled rectifier and three phase inverter, putting forward the SPWM, SVPWM modulation algorithm of current source rectifier and giving proof by simulation.3) Putting forward a bidirectional DC-DC converter which constitutes the DC micro grid, proving the passivity of the bidirectional DC-DC converter, giving the matching passivity control strategy, and doing the simulation.4) Improving a strategy which sampling the IGBT current instead the inductance current of DC-DC converter, and using the methods in two phase interleaved DC-DC converter.5) using the inductance current estimation method, realizing a DC-DC converter which output power is 1.0k W, input DC voltage is 110 V, output DC voltage is 150 V, including hardware design and softare design, and verifying the correctness of improved method by the software debugging and software debugging.