Multilevel Inverter Control System Based On PWM Algorithm Research

As the traditional energy coal and dwindling fossil energy and other non-renewable energy,vigorously develop new energy power generation technology to replace traditional energy in power generation is the inevitable developing trend of power system.Traditional energy exhausting,and solar energy can be unlimited,unlimited,will become the future of new energy dominated in the power system.Solar want converted into electricity,solar photovoltaic system is needed.As the world's largest solar photovoltaic market in China,photovoltaic power generation will also be a benefit of new technology of tens of millions of families.Now the solar photovoltaic power generation technology in China has made certain achievements,formed a certain scale,contains more perfect system of new energy industry.For electric power system,make good use of new energy is also a difficult challenge,photovoltaic grid power generation can be clean,renewable solar power,can not only make full use of clean energy,no pollution,protect the environment,accord with China's current social development.As for electric power system,making good use of new energy is a difficult challenge,inverter plays an important part in photovoltaic grid-connected system.Compared with the traditional two level inverter,Multilevel inverter can effectively reduce the total harmonic content of output waveform,and reduce the equipment cost,as well as are widely used in high-voltage and high-power occasion,therefore,it has a great significance that researching the optimization of multilevel inverter control in the field of photovoltaic grid-connected.This article choose cascaded multilevel inverter as the main research object,first of all,through the analysis the working principle of traditional multilevel inverter topology structure and the merits and demerits of relevant control algorithm,aiming at the shortcomings of the existing control method,a kind of new control method was proposed:Triangular Cascading Phase Shift Rotation Method,which not only can reduce the total harmonic content-of output waveform but also can balance the output power of each basic 2H bridge unit,and stable equipment operation environment.In order to make full use of solar energy,the design of maximum power point tracking of solar photovoltaic power generation,through the DSP using the incremental conductance method according to the voltage and current of photovoltaic panels to determine electric power generated at this time v Board is for the maximum,if not,the value of the DC-DC converter circuit(boost circuit)change voltage,the voltage is stabilized in the vicinity of the maximum value.The simulation platform was built through MATLAB software,this aper analyzes the effect on the total harmonic content of output waveform by factors of sine wave modulation ratio,triangular carrier frequency and the number of cascaded unit,get the conclusion of the optimal parameters.Through the use of DSP,power supply module,full bridge converter module and so on,the hardware experimental platform was built and further verify the feasibility and effectiveness of the new control method.The simulation results and experimental results has proved the validity of this control method.