Research Of High-power T-type Three-level Grid-connected Inverter

The three-level structure of T-type inverter,which is improved by the traditional clamp three-level structure,has gained wide attention and application due to its few elements,low switching loss and high efficiency.It can be used to improve the performance of the system by applying T-type inverter structure to the power generation inverter system.Firstly,based on the mathematical model of photovoltaic cell model,the simulation of photovoltaic cell model under non-occlusion condition and partial occlusion condition is built,and the characteristic curve of photovoltaic cells output parameters is analyzed.Secondly,using the two-stage structure of photovoltaic grid-connected inverter system,the former DC Choper link has made a comparative analysis of the implementation of the maximum power point tracking algorithm for multiple photovoltaic grid-connected key problem.On the basis of summarizing the advantages and disadvantages of the commonly used methods,a method combining fuzzy control and incremental conductance method is discussed,and the advantages are verified by simulation.After the second grade analysis of the topological structure and the two working mode of the T-type inverter,and the mathematical model of the control strategy,the first to use the control method of the traditional PI controller,and the simulation to implement the unit's power factor and to analyze the control performance.Because of the disadvantages of the non-real-time adjustment of the traditional PI controller,a controller using BP neural network to optimize PI controller is discussed,and the simulation is built,and the unit power is connected to the network,and compared with it,it is proved that it not only avoids the traditional PI parameter tuning problem,but also achieves stability faster.And finally introduces the automatic code generation methed,analyzes the setting of important modules,summarizes the common problem solving methods in the experiment process,constructs the low-voltage inverter experiment platform with the traditional full-bridge topology,and makes the basic research,gives the hardware circuit parameters and the selection of the device,and adopts the automatic code generation technology to realize the off-grid inverter.