Design And Realization Of The PV Inverter With Maximum Power Point Tracking

In recent years the technology of new energy has been developed continuously forthe crisis of the global energy and the pollution of the environment. Nowadays,photovoltaic is widely known to people for the reason that there exit a technology whichcan turn solar energy into electricity. But there are a lot of problems while using thephotovoltaic to generate power, such as the instability of the photovoltaic powergeneration system. A PV array is consisted of several PV cells, and if the array is shadedpartially, it would cause illumination unequal, as a result the output characteristic curveof power and voltage would change, so it is with shaded by falling leaves and dust. As weall know that the conversion efficiency of the solar energy is based on the outputcharacteristic curve. In that context, we further study on the characteristics of power andvoltage. In order to take advantage of solar energy conveniently, we bring up a design ofPV inverter which is integrated with the adaptive MPPT (Maximum Power PointTracking) function. The study has important value of engineering application.This paper combines with the MPPT algorithms which are used world widely in thefield of photovoltaic. We finally determine combining the algorithm of APSO (AdaptiveParticle Swarm Optimization) and the algorithm of SPWM (Sinusoidal Pulse WidthModulation) and then transplanting those two algorithms to DSP, so the DSP can controlperipheral circuits. As a result, a continuous AC (Alternating Current) comes out from theoutput of the inverter which does have the maximum power. What’s more, the AC can beused for connecting the grid or loads directly. An overall design scheme of hardware andsoftware is given according to the function of the inverter. We introduce in detail in thedesign of DSP minimum system circuit, signal gathering circuit, high voltage drivercircuit and human-computer interaction circuit. The controller has to execute a series ofcomplex tasks when realizing the processes of maximum power point tracking andinverting. Finally, we embed Real Time Operating System (RTOS) which is called asμC/OS-II in the chip. Then we debug the algorithm program and the OS program in CCScompile environment and download the programs to the DSP.The results show that the design of the hardware and the software meets therequirements. The process of MPPT is executed accurately and rapidly. There never existthe breakdowns of the system. What’s more, the output waves of the inverter have nodistortions and the frequency of the wave or any other indicators meet the requirements.