Study Of High Efficiency MPPT Control Method Of Non-isolated Grid-connected PV Inverter

Inverter is the key component of a PV power generation system, and plays a vital role in the development and utilization of solar energy. And one of the key problem planed to be solved in PV grid-connected inverter is the efficient maximum power point tracking (MPPT) algorithm. The traditional MPPT algorithm easily makes a mistake in a complicated weather condition, and the tracking is too slow and always make the solar panels output have a oscillation problem near the maximum power point.Based on this background, this paper researches on the non-isolated grid-connected PV inverter making stress discuss on the maximum power point tracking (MPPT) control algorithm, then Put forward an improved MPPT algorithm, which can improve the maximum power point tracking module efficiency. And the results of the research have an important practical significance on the grid-connected inverter technology development.The non-isolation PV grid-connected inverter is based on a20KHZ Boost booster circuit and a high frequency control full bridge inverter circuit as its DC/DC and DC/AC circuit, to realize PV grid-connected inverter of maximum power point tracking, we have set up the main circuit platform. In the term of control system this subject is based on DSP TMS320F2808and LM3S8962dinuclear full digital control system. TMS320F2808is used for the system each electric parameters collecting and processing, and controlling each software control module, in order to control every function module. LM3S8962is mainly used for displaying the PV inverter operation state and parameter, and also have the external communication function.This paper based on the solar PV battery electrical characteristics, puts forward the detailed analysis on the common way of MPPT:CVT、Incremental Conductance、 perturbation and observation method P&O、 Fuzzy logic control、 Power feedback method, and expounds the DC-DC conversion circuit (BOOST circuit) to realize the principle of MPPT. What’s more, this paper also has research on the way of Photovoltaic grid-connected generation system inverter signal detection and analyses the perturbation and observation method maximum power point tracking. Basing on theoretical analysis above on, we use simulink to build Photovoltaic battery simulation model, at the same time focusing on the perturbation and observation method and conductance incremental method simulation and experimental research. After comparing their Advantages and disadvantages, setting up a disturbance observation method based on the Boost of maximum power point tracking simulation model.And the result shows that the designed system can better follow maximum power point tracking.Setting up grid-connected test experimental platform, the experiment shows:the non-isolation PV grid-connected inverter has a stable and efficient maximum power point tracking (MPPT) function. The machine efficiency can reach95%, which verifies using disturbance observation method to realize MPPT control is practicability, efficiency and reliability.