Solid State Transformer Control Strategy And Its Dynamic Model Test

In the background of the expansion of the grid size,the emergence of a large number of distributed energy,intelligent distribution network,a large number of nonlinear load growth,the solid state transformer has the following advantages: small volume,high and low voltage DC bus with new energy grid,DC power supply condition,the trend can be controlled,have achieved a side unit power factor operation function,improve dynamic characteristics and optimize the trend of power system.In the distribution network,power electronic transformers are often referred to as energy routers,which is the central nervous system of the future energy network.The above situation shows that it is important to study the solid state transformer.Firstly,the development process of solid state transformer are briefly summarized,this paper introduces the importance of solid state transformer in power transmission,distribution network and the application of new energy,and the several realization and principle of solid state transformer.Secondly,according to the need for the development of distribution system,this paper presents a new type of solid state transformer based on converter of flexible variable topology.In order to provide various forms of energy function to user,a flexible variable topology converter is adopted in the output stage of the solid state transformer,and the various controllers are designed.Third,The solar power systems and energy storage is connected to SST through the low voltage DC bus to further reflect on advantages of the new energy,a kind of three heavy DC/DC converter is used as interface of the energy storage system,and a coordinated control of energy strategies converter is proposed,solar power systems and energy control storage is designed.A new type of solid state transformer and a new solid-state transformer with solar power systems and energy storage are simulated by simulation software.The simulation results verified the topology and control strategy of the new solid state transformer and a new solid-state transformer with solar power and energy storage systems is feasible and effective.Built a new solid state transformer dynamic simulation test platform based on DSP F28335,and introduced the design process of the new main circuit of solid state transformer and control strategies.The software design is based on Simulink automatic code generation.The technical advantages of the new solid state transformer are verified by the dynamic simulation test platform.