Study On Distribution System Of Multi Function Power Electronic Transformer

With the rapid development of social economy, the electric power system gauge of mold is more and more big, gradually increase the proportion of new energy grid, nonlinear load, precision instruments and sensitive load is applied at the same time, in this situation, the user to the power supply security, reliability and power quality put forward higher requirements. Distribution transformer is one of the most close to the user equipment, so its reliability, quality of power supply and economic indicators will directly affect the performance of electrical equipment. The traditional transformer with high voltage grade, large capacity and technological level of mature development advantages, but in the process of development its function has not changed, only the voltage level conversion, electrical isolation and power transmission, therefore it has been difficult to satisfy users to power quality put forward higher request. With the development of power electronic transformer(referred to as PET) appears, it brings a new idea for solving these problems.PET not only has all the functions of traditional transformer, but also has the advantages of small volume and light weight, can inhibit the propagation of voltage fluctuation 、harmonic and short circuit fault, it plays a great role in improving the power quality. PET has both AC and DC link, the PET can be combined with FACTS devices, to the characteristics of the PET has to solve the potential of electric power system of power quality problems, so the study of PET for building a green power grid and smart grid has very important significance. This paper first summarizes the research status at home and abroad; Second, introduces the working principle of PET and the typical topology analysis, based on this, put forward a new kind of PET topology, namely PET single and three phase hybrid power supply topology; Third, PET mathematical model is derived, and then introduced the PET control strategy; Fourth, introduced the main components of PET; Fifth, using PSCAD tools for three-phase PET and PET single, three-phase hybrid power supply for the simulation and analysis, the ideal result is obtained through the simulation, fully verified the PET for power quality has great improvement action.