Three-phased Photovoltaic Grid-connected Inverter And Control

The photovoltaic power generation process is making the direct current to thealternating current and transmissing to the grid, the inverter is the core equipment of theconnection between solar cells and grid, its stability and reliability determine the qualityof the electrical energy transmission.In order to improve the quality of power generation,a in-depth analysis on hardware and software of the system have done. This paper havemade a more detailed mathematical derivation and theoretical simulation on these twoaspects, have also made a preliminary validation of these algorithms and given thecorresponding experimental results on a hardware platform.First, this paper analyzes the structure of the photovoltaic array, then builds asimulation model of the PV array. The exist of maximum output power of the P-U curvecan be seen from the simulation model, a deep thinking of the maximum power pointtracking also have done on this basis, and proposes a new algorithm simulation showsthat has a better tracking results compared with the traditional algorithm.Then, this paper describes the topology of the inverter, and selects single-stagetopology as a research object. For L-and LCL-filter structure, the mathematical model isdifferent, and the net current control algorithms also need to do the appropriate change.In this paper,direct current control is used on voltage source inverter, and respectivelyanalysises hysteresis control and the triangle wave comparing control. In particular,because decoupling of the LCL type filter in the synchronous coordinate system iscomplicated, this paper introduces PR control, sets up a matlab simulation to simulateand give comparative analysis of the above algorithm.Finally, this paper gives theoretical calculations of the L-and LCL-filter andsampling circuit, builds an experimental platform using TMS320F2812as core controllerto do a preliminary validation of the theoretical algorithm, and gives the experimental waveforms.