Design Of Three-phase Grid Connected Inverter Based On DSP

With the development of energy shortage and environmental pollution, solar energy, wind energy and other new energy has drawn more and more attentions. From the problems of its own noise, wind energy is only suitable for setting in more remote, less populated areas, and from the economic aspect, through large-scale investment to achieve the effect of wind energy utilization. China is a country with a large population, the per capita energy consumption is very low, but because of the great pressure of energy demand growth, the contradiction between energy supply and economic development is particularly prominent, in the development and utilization of renewable energy efforts at the same time, vigorously improve the efficiency but also an important strategic choice of energy utilization. Solar energy with its widespread existence, storage, use of unlimited clean by people of all ages, but in the use and grid connected solar aspect, there are still many problems need further discussion and study.Based on solar photovoltaic power generation system, this paper firstly introduced the structure of grid inverter classification, working principle and introduces the three-phase grid inverter topology. Control strategy of grid connected inverter is introduced briefly in this paper, analysis and selection of control method of pulse width modulation, and the feasibility of the space vector SVPWM algorithm is validated by computer simulation. In the final, analysis current PI control strategy based on feed forward decoupling SVPWM, given the whole simulation model of three-phase grid inverter, through the simulation output waveform to verify the design correctness. Based on the understanding of the working principle of solar cells, the simulation verify the characteristics of photovoltaic solar panels, introduces several methods to achieve maximum power tracking, finally selects the fixed step perturbation and observation method, and gives the control process.Upon completion of the above analysis, the hardware and software of three-phase grid inverter are designed. Hardware mainly includes the selection of the power switch tube, the design of drive circuit, sampling circuit, overcurrent and overvoltage protection, the selection of the AC filter inductance parameters. Software is mainly selected TMS320F2812 DSP control chip, introduces some of the characteristics of the chip, to complete the construction of the development platform, designs the related software, including software project's main idea and main control program control flow.In this paper, designed and completed the production of photovoltaic (pv) grid inverter in the end, completed a prototype of power board display and waveform test.