Research And Design Of Inverter For Photovoltaic Grid-connected System

In today’s world, the environmental pollution and energy shortageproblem increasingly serious.Looking for the new energy, the use of the newenergy, is the inevitable result of social development trend，looking for areserve big, non-pollution new energy has become the world’s importantstrategic plan.In many new energy,no matter quality or quantity,solar isundoubtedly the most famous of these. So, how to use the solar energy, howto more efficient use solar energy, become the urgent problems needresearchers to solve.Nowadays, the tendency of solar energy use is grid–connectedgeneration system. This paper to maximize use of solar energy, the highquality power gave back to the electric grid as the main target, researchedand designed the inverter for PV grid-connected system. The main researchcontents:First of all, according to the requirement of design and performanceindicators, chose the type of the system,confirmed the system controlstrategy, modulation mode and filter’s structure and parameters. Based onthis, given the mathematic model of the system, and analysis the systemperformance in different control modes, provided extremely effective helpto after hardware design.Second, the MPPT (the maximum power point tracking) is always metin photovoltaic system, this paper introduces some commonly used MPPTscheme of the several scheme in the detailed analysis and contrast, given theadvantages and disadvantages of several schemes, according to the researchand development in the actual conditions,chose the MPPT scheme for thispaper.Then, according to the TI company’s digital processing chipTMS320F2812as the controller chip, designed the inverter hardware circuit and software process. Hardware circuit mainly includes: inverter maincircuit, signal acquisition circuit, DSP peripheral circuit, drive circuit, theprotection circuit. Software of mainly has: the design of the software andphase lock loop, produce of SPWM signal.Finally, to prevent the island effect of the photovoltaic (PV) gridsystem, this paper analyzed the use of active disturbance to the solution ofprevent island effect, and the simulation results proved the feasibility.