Research On Three-level Inverter Based On DSP Control

With the development of new energy generation technology,multi-level technology,mainly three-level technology,has been applied to grid-connected inverters for wind power generation and solar power generation.Digital control method is more and more widely used in power electronic converters.Compared with the traditional analog control,digital control system has high accuracy,robustness and flexibility.In this paper,the switching state function analysis method is introduced.Diode clamped three-level inverters are taken as the research object,and the digital control chip of DSP is taken as the core.A low-power multi-level inverters with digital control are designed and implemented.In this paper,a functional analysis method of switching state is proposed.The mathematical function relationship between switching state and switching angle is established.The driving signal required by the switch is obtained by controlling the switching angle.Firstly,the switching state functionalization of half-bridge inverters is analyzed,and the topological structure of diode clamped three-level inverters and N-level inverters are deduced by switching module transformation method.Secondly,the switching state functionalization analysis of three-level inverters is carried out.Then the analysis method is extended to level inverters.On the basis of system modeling and analysis,the hardware design and software design of the system are carried out.The hardware part mainly includes the main circuit,control circuit and isolation circuit.The components needed in each part are designed and selected,and the PCB board is drawn.The software part takes the ICETEK-LF2407-A evaluation board using the TMS320LF2407 A DSP chip as the core,carries out the design of the main program and interrupt program,and completes the initialization process and algorithm implementation process of the DSP needed by the system.The application program is mainly programmed in C language,and the assembly language is nested.The software flow chart and experimental results are given,and the experimental waveform is analyzed and explained.show that the method of switching state functionalization is feasible.Finally,the main research contents of this paper are summarized,the main research conclusions are given,the shortcomings in the design process are pointed out,and the next work to be done is put forward.