Design Of Photovoltaic Grid Connected Inverter Based On DSP

Now, as the population becomes lager and the economy development rapidly, the sonsumption of energy comes greater.Also the fossil energy is running out, the energy crisis may break out anytime. Photovoltaic(PV) power generation develop sharply as the most highest potential clean energy in rencent years. The PV grid-connected system becomes the primary research field because it’s the only way to solve the energy crisis. The PV grid-connect system has three technical difficulties, such as Maximum Power Point Tracking(MPPT),grid-connected control strategy and islanding detection. The purpose of this paper is to develop a PV grid-connected inverter with high transmission quality, good stability based on the digital signal processor(DSP) controler.First, we choose the two levels grid-connected inverter by comparing the advantage and disadvantage of various structures.The Pre-amplifier is using the Boost converter to realize the MPPT function and the PowerAmp adopt full bridge inverter to realize the constravariant function.Second, a model of PV battery is built with Matlab/SimuLink through the deep investigate of the PV battery theory. The output curve of the PV battery with the outer environment concerned is acquired. The variable step perturbation method is proposed through introduceing sveral traditional method of the MPPT and comparing those advantages and disadvantages.Thrid, this chapter analysis the working principle of the Boost convernter and design the design the parameters of the capacitance and the inductance, introduce the types of power switch and it’s selection, and design the parameter of the LC filter ciucuit.Fourth, by comparing the various control methods, the double loop control stratege are selected. Then the mathematical model of full bridge inverter is established. The parameters of the voltage loop and curunt inner loop are designed based on the model.The whole inverter system is established under Matlab/SimuLink in order to verify its feasibility, and the reults ars given.Finally, the PV grid-connected inverter is carried out based on the double loop control model, and the hardware and software are completed with the TMS320F2812 as the control chip.A test platform is built and the photovoltaic grid inverter is tested. The output curves of the prototype is observed and the result shows that this PV grid-inverter achieve the design function and achieve the designed purpose.