Design And Control Technology Of Single-phase Inverter Based On DSP

Following the development concepts of "carbon neutrality" and "carbon peaking",renewable energy power generation technologies such as photovoltaics and wind power,have been rapidly improved.Inverters are the important connection between renewable energy sources and grids.And the control performance of the inverters play an important role on the safety and stability of grids.In this thesis,novel methods for the L-type converters and LC-type converters are proposed respectively,and they are called the first-order switching sequence control and the second-order switching sequence control based on the sliding mode technology,the effect of the control parameter is analyzed in the theoretical,and the corresponding simulation models are built to verify the effectiveness of the proposed methods.At the same time,the single-phase inverter hardware experiment platform is designed,the software development of the proposed methods is completed,and the experimental verification is completed through the joint debugging of software and hardware.It is ensures that the proposed methods achieve accurately tracking for L-type converters and LC-type converters.At beginning,this thesis proposes the first-order switching sequence control technology for single-phase L-type inverters.By establishing the mathematical model of L-type inverters,the switching sequence controller is proposed based on the sliding mode control.Then,the steady-state accuracy and dynamic performance of the proposed method are analyzed.On this basis,the effectiveness of the proposed method is verified by MATLAB.The simulation results show that the first-order switching sequence control has good steady-state accuracy and fast dynamic performance.Then,based on the proposed first-order switching sequence control,this thesis proposes a sliding-mode-based second-order switching sequence control for LC-type inverters.By circuit analysis and discretization,the mathematical model of the LC-type inverters is established.In addition,based on the established mathematical model and sliding mode control theory,the second-order switching sequence controller is designed.And the effect of control parameters on system performance is theoretically demonstrated.Furthermore,the effectiveness of the second-order switching sequence control is verified by simulation.It shows that the proposed method has good dynamic performance and high steady-state accuracy.In addition,in order to further verify the control performance of the proposed first-order switching sequence control technology and second-order switching sequence control,this thesis designs a hardware platform based on DSP,and gives the overall scheme and technical indicators of the inverter hardware circuit.According to the circuit function division,the power main circuit,drive circuit,control circuit and other hardware circuits are designed in detail.Then,the PCB wiring is optimized,and the PCB design of the hardware circuit is completed.Finally,based on CCS,this thesis has completed the main program module,PWM interrupt service program module,sampling program module and protection program module.Then,the switching sequence control technology algorithm are implemented on the established platform.According to the experimental results,the parameters of the proposed methods are discussed.The experiments show that the proposed methods have good steady-state accuracies.It verifies the effectiveness of the proposed control methods.