The Harmonic Elimination And Research On Reliability Based On Back-to-Back Three-Level Neutral-Point-Clamped Converters

As back-to-back converter has the advantages of adjustable power factor and energy two-way flow,it is widely used in the field of renewable energy power generation and micro-grid.And with the high-speed expansion of wind power systems and other emerging areas.As the core device,the back-to-back converter technology has also been widely attention.Therefore,it is of great significance to study the control performance of back-to-back converters.In this paper,three-level back-to-back converter as a research object,and this paper focuses on harmonic elimination,loss analysis and comparison of such issues as research,the main research contents of this paper are as follows.1.The working principle of the voltage-type back-to-back converter is analyzed.At the same time,the three modulation strategies of SPWM,SVPWM and SHEPWM are introduced.2.In order to solve the switching angle of SHEPWM modulation strategy,some traditional algorithms are introduced in this part,such as polynomial interpolation,genetic algorithms,etc.,finally,this paper puts forward the quantum genetic algorithm.The results are obtained by MATLAB/Simulink S-function,and compared with genetic algorithm.The simulation model is brought into the result,and using simulation and experiments to verify the feasibility of the analysis method.3.The working state and switching process of the power device are analyzed,and the loss model of the power switching devices is established.The loss in different modulation mode is analyzed and compared by building simulation and experiments.4.The hardware circuit platform of voltage back-to-back converter is designed,which includes the design and debugging of main circuit,driving circuit,signal sampling circuit and control circuit.Verify the feasibility and correctness of this study by simulation and experiments.